WorldWideScience

Sample records for tension ring ctr

  1. [Phacoemulsification of subluxated lens with capsular tension ring implantation].

    Science.gov (United States)

    Dorecka, Mariola; Rokicki, Wojciech; Nita, Malgorzata; Krysik, Katarzyna; Nita, Ewa; Sikorska, Aleksandra; Romaniuk, Wanda

    2007-01-01

    To evaluate long term results of phacoemulsification with PC IOL and capsular tension ring (CTR) implantation in lens subluxation. The study comprised of 134 patients--146 eyes with subluxated lens. In all cases phacoemulsification with PC IOL and CTR implantation was performed. No intaroperative complications has occured. Postoperative complications included: inflammation in the anterior chamber in 3 eyes (2.1%), retinal detachment in 2 eyes (1.4%). In all cases there was no PC IOL decentration. (1) CTR facilitates phacoemulsification with PC IOL implantation in lens subluxation. (2) Phacoemulsification of subluxated lens with PC IOL and CTR implantation seems to be safe and effective procedure.

  2. Use of capsular tension ring in phacoemulsification. indications and technique

    Directory of Open Access Journals (Sweden)

    Lanzetta Paolo

    2002-01-01

    Full Text Available The capsular tension ring (CTR was originally introduced to reinforce the zonule in eyes with zonular dehiscence and to prevent capsular phimosis in eyes at risk for postoperative capsular shrinkage. Since then, other designs and applications have been developed and described. Modified CTRs with shields can be used in eyes with iris coloboma. A CTR with loops is intended for scleral fixation. Studies are underway to determine if the presence of the CTR helps avoid or limit capsular opacification. A number of different insertion techniques with the aid of manipulators, injectors and traction sutures have been described. We have developed a technique that is particularly effective in cases of zonular dehiscence due to its low solicitation to the damaged bag.

  3. Surgical management of spontaneous in-the-bag intraocular lens and capsular tension ring complex dislocation

    Directory of Open Access Journals (Sweden)

    Uzeyir Gunenc

    2014-01-01

    Full Text Available We describe a technique to manage late spontaneous intraocular lens (IOL and capsular tension ring (CTR dislocation within the intact capsular bag. The subluxated IOL and CTR complex can be positioned in a closed chamber and fixed to the pars plana at both 3 and 9 o′clock quadrants with the presented ab externo direct scleral suturation technique which provides an easy, safe and effective surgical option for such cases.

  4. Clinical observation of capsular tension ring implantation in congenital lens subluxation treating by phacoemulsification

    OpenAIRE

    Liang-Nan Sun; Bai-Jun Li; Yuan-Fei Zhu; Xin-Hua Liu

    2017-01-01

    AIM: To evaluate the clinical results of capsular tension ring(CTR)implantation in phacoemulsification for eyes with congenital lens subluxation. METHODS: This study comprised 18 patients(31 eyes)with congenital ectopia lentis. All patients received phacoemulsification with CTR and intraocular lens(IOL)implantation. Visual acuity before and after surgery were examined. IOL decentration were measured with Image-Pro Plus image processing software. The complications were also recorded preoperati...

  5. Clinical observation of capsular tension ring implantation in congenital lens subluxation treating by phacoemulsification

    Directory of Open Access Journals (Sweden)

    Liang-Nan Sun

    2017-07-01

    Full Text Available AIM: To evaluate the clinical results of capsular tension ring(CTRimplantation in phacoemulsification for eyes with congenital lens subluxation. METHODS: This study comprised 18 patients(31 eyeswith congenital ectopia lentis. All patients received phacoemulsification with CTR and intraocular lens(IOLimplantation. Visual acuity before and after surgery were examined. IOL decentration were measured with Image-Pro Plus image processing software. The complications were also recorded preoperatively and postoperatively. RESULTS: Uncorrected vision of all eyes increased after surgery, and all cases had different degree of IOL decentration after surgery. Two eyes received CTR scleral fixation 3mo after surgery because the IOL decentration aggravated during the follow-up period. CONCLUSION: Phacoemulsification with CTR and IOL implantation is effective and safe for congenital lens subluxation. The implantation of CTR increase the stability of the capsular bag, improve the safety of surgery, and maintain the right position of IOL. CTR scleral fixation is a effective supplement for progressive cases.

  6. Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children

    OpenAIRE

    Das, Pranab; Ram, Jagat; Brar, Gagandeep Singh; Dogra, Mangat R

    2009-01-01

    Purpose : To evaluate the outcome of intraocular lens (IOL) implantation using capsular tension ring (CTR) in subluxated crystalline or cataractous lenses in children. Setting : Tertiary care setting Materials and Methods : We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90° up to 210° after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior ...

  7. Effect of a capsular tension ring on axial intraocular lens position.

    Science.gov (United States)

    Weber, Maria; Hirnschall, Nino; Rigal, Karl; Findl, Oliver

    2015-01-01

    To assess the effect of a capsular tension ring (CTR) on the postoperative anterior chamber depth (ACD). Vienna Institute for Research in Ocular Surgery, Department of Ophthalmology, Hanusch Hospital, Vienna, Austria. Prospective observer- and patient-masked randomized trial. Bilateral small-incision cataract surgery with implantation of a hydrophobic acrylic single-piece intraocular lens (IOL) (Tecnis ZCB00) was performed using a standard technique. Each patient received a CTR in 1 eye (CTR group) and no CTR in the fellow eye (control group). The ACD was measured preoperatively with biometry (IOLMaster 500) and at 1 hour and 12 weeks postoperatively using partial coherence interferometry (ACMaster). The subjective refraction was assessed at 12 weeks. Sixty eyes (30 patients) were included. Preoperatively, the mean axial length was 23.36 mm ± 1.55 (SD) (range 21.01 to 29.46 mm) in the CTR group and 23.37 ± 1.70 mm (range 21.14 to 28.84 mm) in the control group and the mean ACD was 3.06 ± 0.45 mm (range 2.25 to 4.16 mm) and 3.03 ± 0.47 mm (range 2.18 to 4.10 mm), respectively. The differences were not statistically significant (P=.148 and P=.074, respectively). The mean postoperative ACD was 4.83 ± 0.46 mm (range 3.84 to 5.76 mm) in the CTR group and 4.81 ± 0.43 mm (range 3.67 to 5.65 mm) in the control group. The difference between the groups was not statistically significant (P=.329). Implantation of a CTR had no significant influence on the postoperative axial IOL position. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Clinical application of capsular tension ring on cataract surgery in patients with pseudoexfoliation syndrome after trabeculectomy

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2014-09-01

    Full Text Available AIM:To investigate the safety and efficacy of capsular tension ring(CTRinsertion combined with phacoemulsification and intraocular lens(IOLimplantation in patient with pseudoexfoliation syndrome after anti-glaucoma surgery.METHODS: A retrospective study was conducted of 10 eyes from 10 cataract patients with pseudoexfoliation syndrome following trabeculectomy surgery, and who underwent CTR insertion combined with phacoemulsification and IOL implantation between January, 2012 and June, 2013. All cases had nuclear cataracts(nuclear hardness Ⅱ 1 eye, nuclear hardness Ⅲ 4 eyes, nuclear hardness Ⅳ 5 eyes. One case with Ⅳ nuclear hardness cataract had iridodonesis and lens subluxation. Postoperative visual acuity, intra- and post-operative complications, anterior capsular opening, IOL position, and postoperative intraocular pressure(IOPwere assessed. Follow-ups ranged from 3 to 14mo. The t test was used to analyze the variables studied.RESULTS: All patients had a successful CTR insertion combined with phacoemulsification and IOL implantation. A modified CTR insertion was performed in one case, the others underwent a standard CTR insertion. The best corrected visual acuity(BCVAwas ≥0.5 in 3 eyes and 0.3-t=1.9955, P>0.05. The most common intrao- and post-operative complications were corneal edema, small pupil, residual cortex, spontaneous zonular dialysis.CONCLUSION: Suitable CTR insertion in appropriate occasion may be beneficial to patients with pseudoexfoliation syndrome after trabeculectomy during cataract surgery. It prevents the IOL decentration and decrease the surgical complication. Less complication occurs at the early stage.

  9. Chronic and Intermittent Angle Closure Caused by In-The-Bag Capsular Tension Ring and Intraocular Lens Dislocation in Patients With Pseudoexfoliation Syndrome.

    Science.gov (United States)

    Bochmann, Frank; Strümer, Jörg

    2017-11-01

    A subluxation or dislocation of the intraocular lens (IOL) is a well-known complication after cataract surgery in patients with pseudoexfoliation syndrome (PEX). Capsular tension rings (CTR) are frequently used to prevent postoperative complications caused by zonular weakness. Here we present a series of 7 cases, 2 with intermittent and 5 with acute angle closure caused by a combination of PEX-associated zonular weakness and a resulting unstable capsular bag-CTR-IOL complex. We describe the typical clinical course with elevated intraocular pressure, myopic shift, and shallowing of the anterior chamber in 7 patients with a new type of secondary angle closure. The diagnostic challenges and treatment options are discussed in detail. In all cases, the mechanism of angle closure identified by ultrasound biomicroscopy was an anterior dislocation of the peripheral iris by the capsular bag-CTR-IOL complex. The IOL was removed together with the capsular bag and the CTR and replaced by an iris-fixated IOL in all cases. We present a new type of secondary angle closure caused by an anterior dislocated capsular bag-CTR-IOL complex. The cause of both, this atypical presentation and the ineffectiveness of the laser peripheral iridotomy is the large diameter CTR. Therefore CTR implantation might also be the source of late postoperative complications. If a secondary angle closure associated with PEX and unstable capsular bag-CTR-IOL complex is encountered, IOL explantation and replacement by an iris-fixated IOL is a simple and effective treatment option.

  10. Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children.

    Science.gov (United States)

    Das, Pranab; Ram, Jagat; Brar, Gagandeep Singh; Dogra, Mangat R

    2009-01-01

    To evaluate the outcome of intraocular lens (IOL) implantation using capsular tension ring (CTR) in subluxated crystalline or cataractous lenses in children. Tertiary care setting. We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90 degrees up to 210 degrees after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior capsular opacification (PCO). Age of the patient ranged between five to 15 years. Out of 18 eyes, seven had traumatic and 11 had spontaneous subluxation of crystalline or cataractous lens. Phacoemulsification was successfully performed with CTR implantation in the capsular bag. Intraoperative zonular dialysis occurred in two eyes. Anterior vitrectomy was performed in six eyes to manage vitreous prolapse. IOL implanted was polymethyl methacrylate (PMMA) in eight eyes, hydrophobic acrylic in seven and hydrophilic acrylic in three. Follow-up ranged from 24 months to 72 months. Sixteen eyes had a best corrected visual acuity of 20/40 or better. Nine eyes developed significant PCO and were managed with Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser posterior capsulotomy. One eye with acrylic IOL in the capsular bag had IOL dislocation after two years which was managed with vitrectomy and secondary trans-scleral fixation of IOL. Phacoaspiration with CTR implantation makes capsular bag IOL fixation possible in most of the eyes with subluxated crystalline or cataractous lenses. PCO still remains a challenge in children with successful phacoaspiration with CTR implantation.

  11. Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children

    Directory of Open Access Journals (Sweden)

    Das Pranab

    2009-01-01

    Full Text Available Purpose : To evaluate the outcome of intraocular lens (IOL implantation using capsular tension ring (CTR in subluxated crystalline or cataractous lenses in children. Setting : Tertiary care setting Materials and Methods : We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90° up to 210° after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior capsular opacification (PCO. Results : Age of the patient ranged between five to 15 years. Out of 18 eyes, seven had traumatic and 11 had spontaneous subluxation of crystalline or cataractous lens. Phacoemulsification was successfully performed with CTR implantation in the capsular bag. Intraoperative zonular dialysis occurred in two eyes. Anterior vitrectomy was performed in six eyes to manage vitreous prolapse. IOL implanted was polymethyl methacrylate (PMMA in eight eyes, hydrophobic acrylic in seven and hydrophilic acrylic in three. Follow-up ranged from 24 months to 72 months. Sixteen eyes had a best corrected visual acuity of 20/40 or better. Nine eyes developed significant PCO and were managed with Neodymium Yttrium Aluminum Garnet (Nd:YAG laser posterior capsulotomy. One eye with acrylic IOL in the capsular bag had IOL dislocation after two years which was managed with vitrectomy and secondary trans-scleral fixation of IOL. Conclusions : Phacoaspiration with CTR implantation makes capsular bag IOL fixation possible in most of the eyes with subluxated crystalline or cataractous lenses. PCO still remains a challenge in children with successful phacoaspiration with CTR implantation

  12. Comparative evaluation of rotational stability and visual outcome of toric intraocular lenses with and without a capsular tension ring.

    Science.gov (United States)

    Rastogi, Anju; Khanam, Samreen; Goel, Yashpal; Thacker, Prolima; Kumar, Prateek

    2018-03-01

    To evaluate the rotational stability of toric intraocular lens (IOL) when co-implanted with a capsular tension ring (CTR) as compared to that of a toric IOL without a CTR. This was a prospective randomized clinical trial performed in a tertiary care centre in India. Fifty adult human eyes with visually significant cataract and regular corneal astigmatism ≥1.5D divided into two groups of 25 eyes each, A and B by simple randomization. Eyes with corneal pathology, lens subluxation, and a specular endothelial cell count IOL. In Group A, a CTR was put in the bag before IOL implantation. The groups were called for follow-up on day 1, 1 week, 1 month, and 3 months, postoperatively. The axis of the toric IOL on each visit was measured by slit lamp imaging in retroillumination and analyzed digitally. Mean rotation of toric IOL at 3 months postoperatively was 1.85 ± 1.72° in Group A and 4.02 ± 2.04° in Group B. The difference was statistically significant (P = 0.003). Coimplantation of a CTR is a safe and effective technique for ensuring better rotational stability of toric IOLs.

  13. Comparative evaluation of rotational stability and visual outcome of toric intraocular lenses with and without a capsular tension ring

    Directory of Open Access Journals (Sweden)

    Anju Rastogi

    2018-01-01

    Full Text Available Purpose: To evaluate the rotational stability of toric intraocular lens (IOL when co-implanted with a capsular tension ring (CTR as compared to that of a toric IOL without a CTR. Methods: This was a prospective randomized clinical trial performed in a tertiary care centre in India. Fifty adult human eyes with visually significant cataract and regular corneal astigmatism ≥1.5D divided into two groups of 25 eyes each, A and B by simple randomization. Eyes with corneal pathology, lens subluxation, and a specular endothelial cell count <2000/mm2 were excluded from the study. The eyes in both the groups underwent standard phacoemulsification and were implanted with a toric IOL. In Group A, a CTR was put in the bag before IOL implantation. The groups were called for follow-up on day 1, 1 week, 1 month, and 3 months, postoperatively. The axis of the toric IOL on each visit was measured by slit lamp imaging in retroillumination and analyzed digitally. Results: Mean rotation of toric IOL at 3 months postoperatively was 1.85 ± 1.72° in Group A and 4.02 ± 2.04° in Group B. The difference was statistically significant (P = 0.003. Conclusion: Coimplantation of a CTR is a safe and effective technique for ensuring better rotational stability of toric IOLs.

  14. Joining mechanism with stem tension and interlocked compression ring

    Science.gov (United States)

    James, Allister W.; Morrison, Jay A.

    2012-09-04

    A stem (34) extends from a second part (30) through a hole (28) in a first part (22). A groove (38) around the stem provides a non-threaded contact surface (42) for a ring element (44) around the stem. The ring element exerts an inward force against the non-threaded contact surface at an angle that creates axial tension (T) in the stem, pulling the second part against the first part. The ring element is formed of a material that shrinks relative to the stem by sintering. The ring element may include a split collet (44C) that fits partly into the groove, and a compression ring (44E) around the collet. The non-threaded contact surface and a mating distal surface (48) of the ring element may have conic geometries (64). After shrinkage, the ring element is locked onto the stem.

  15. A retrospective study of the indications and outcomes of capsular tension ring insertion during cataract surgery at a tertiary teaching hospital

    Directory of Open Access Journals (Sweden)

    Wang BZ

    2013-03-01

    Full Text Available Bob Z Wang, Elsie Chan, Rasik B Vajpayee The Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Centre for Eye Research Australia, University of Melbourne, East Melbourne, Victoria, Australia Background: The purpose was to determine preoperative indications, intraoperative procedures, and outcomes of capsular tension ring (CTR insertion during cataract surgery. Methods: A review of all patients undergoing cataract surgery with insertion of a CTR between July 2000 and June 2010 was conducted at The Royal Victorian Eye and Ear Hospital, a large tertiary teaching hospital in Victoria, Australia. Information relating to each patient's demographic details, preoperative assessment, surgical procedure, and postoperative assessment were obtained. Results: Eighty-four eyes of 82 patients were included in this study. The main indications for CTR insertion were previous trauma, pseudoexfoliation syndrome, and mature cataracts. Twenty-one eyes (25.0% did not have any obvious preoperative indication. A posterior capsule tear was the most common intraoperative complication (3.6%. An intraocular lens was successfully implanted in the bag in 72 eyes (85.7%. Postoperatively, the most common complications were a decentered intraocular lens (8.3% and persistent corneal edema (6.0%. Overall, 61 eyes (72.6% had better postoperative visual acuity compared with preoperative acuity, with 67 patients (79.8% achieving vision of 20/40 or better. Conclusion: For the majority of cases, CTR use in complex cataract surgeries is associated with improved postoperative outcomes. CTR implantation is most commonly required in patients with known risk factors for zonular instability. Keywords: capsular tension ring, cataract extraction, indications, outcomes

  16. Application of capsular tension ring combined with iris hooks in phacoemulsification of traumatic cataract with lens subluxation

    Directory of Open Access Journals (Sweden)

    Li-Gang Li

    2015-07-01

    Full Text Available AIM: To evaluate the clinical efficacy and safety of capsular tension ring(CTRcombined with iris hooks in eyes with large traumatic zonular dialysis or weakness that underwent micro-incision coaxial phacoemulsification with posterior chamber(PCintraocular lens(IOLimplantation. METHODS: This prospective study was carried on 21 patients(21 eyeswith traumatic cataract and traumaticzonular dialysis(RESULTS: The mean follow-up period was 3~12mo. No serious postoperative complication was found. BCVA in our cases: 0.8 in 5 eyes. IOPs were in normal range too. The IOLs in 20 eyes remained the required position to the final follow-up examination except one eye in which the PC IOL was dislocated into vitreous cavity due to a postoperative spontaneity PCR, and in which vitrectomy and IOL suture fixation was performed.CONCLUSION: In cases of cataract associated with traumatic zonular dialysis(<180°, by setting the rational parameters of phacoemulsification, the CTR and iris hooks are found to be efficient in preventing IOL decentration and reducing operation complication. In our cases, the CTR combined with iris hooks is relatively safe application.

  17. In-the-bag capsular tension ring and intraocular lens subluxation or dislocation: a series of 23 cases.

    Science.gov (United States)

    Werner, Liliana; Zaugg, Brian; Neuhann, Tobias; Burrow, Michael; Tetz, Manfred

    2012-02-01

    To describe clinical and pathologic findings from cases of in-the-bag capsular tension ring (CTR) and intraocular lens (IOL) subluxation or dislocation. Retrospective case series with clinicopathologic correlation. Twenty-three explanted subluxated/dislocated capsular bags containing a CTR and an IOL explanted in Europe and submitted in fixative to the Berlin Eye Research Institute. Standard gross and light microscopy of specimens, complete histopathologic analyses of selected specimens done at the University of Utah, as well as questionnaire sent to explanting surgeons, and patient chart review, when available. Lens design, material, and abnormalities, capsular bag anomalies, patient demographic data, surgical dates, and presence or absence of known risk factors. Patients were aged 76.31 ± 8.24 years at explantation, which was performed 81.5 ± 32.2 months after implantation. The IOLs in these cases were 3-piece hydrophobic acrylic (N = 11), 1-piece hydrophobic acrylic (n = 6), 3-piece silicone (n = 4), or 1-piece hydrophilic acrylic (n = 2) designs; all CTRs were made of poly(methyl methacrylate). Available information on associated ocular conditions included pseudoexfoliation (n = 17), glaucoma (n = 4), vitrectomy/retina surgery (n = 3), and trauma (n = 1). Complete histopathologic assessment in 3 specimens showed signs consistent with pseudoexfoliation, without available history related to this condition in one of the cases. Moderate/severe degrees of Soemmering's ring formation and capsulorhexis phimosis were observed or reported in 13 and 11 specimens, respectively. Fourteen eyes were implanted and explanted by the same surgeon, with an interval of 92.7 ± 23.4 months between the procedures. His rate of explantation because of subluxation/dislocation was 0.76% of the CTRs implanted during the time considered. Explantation because of postoperative subluxation or dislocation of CTR-IOL-capsular bag complexes occurred approximately 6.8 years after implantation

  18. Prevention of after-cataract by application of heparin treatment of capsular tension ring in Marfan syndrome and subluxation of lens

    Directory of Open Access Journals (Sweden)

    Zhong-Qing Li

    2013-08-01

    Full Text Available AIM: To investigate the effect of heparin treatment on capsular tension ring(CTRin the prevention of after-cataract postoperative patients with Marfan syndrome and subluxation of lens.METHODS: Totally 34 cases(56 eyeswere divided randomly into experimental and control groups. Preoperative heparin 12500 units was added to 500mL Ringer's infusion, and CTR was dealt with heparin stock solution soak for 20 minutes in experimental group; there was no any drugs in the control group's solution, and CTR was not dealt with heparin. Postoperative IOP, anterior chamber reaction, corneal edema, IOL position, posterior capsular opacification were observed.RESULTS: There was statistically significant difference in the posterior capsular opacification between the heparin group(13.3%and the contral group no-heparin(69.2%(PCONCLUSION: The present results indicate that there is the preventive effect on posterior capsular opacification by CTR soaked in heparin in postoperative patients with Marfan syndrome and subluxation of lens, thus contributing to the recovery of visual function.

  19. Measurement of calcium influx in tethered rings of rabbit aorta under tension

    International Nuclear Information System (INIS)

    Gleason, M.M.; Ratz, P.H.; Flaim, S.F.

    1985-01-01

    Calcium (Ca) influx in vascular smooth muscle is routinely measured in untethered preparations not under passive stretch, and Ca influx data are correlated with data for steady-state isometric tension obtained under parallel conditions from tethered preparations under passive stretch. The validity of this method was tested by simultaneous measurement of Ca influx and tension in tethered rings of rabbit thoracic aorta. Ca influx ( 45 Ca 3-min pulse) and tension were measured at 3 and 30 min after norepinephrine (NE) or KCl and under control (no agonist) conditions. Active tension was significantly altered by variations in passive tension. Ca influx was unaffected by passive tension under control, NE, or KCl conditions, and results were similar at 3 and 30 min. The results confirm the validity of correlating Ca influx data from untethered rings with steady-state contractile response data obtained from tethered rings under similar experimental conditions

  20. Combined special capsular tension ring and toric IOL implantation for management of post-DALK high regular astigmatism with subluxated traumatic cataract.

    Science.gov (United States)

    Kandar, Asim Kumar

    2014-07-01

    We report a case of 18-year-old male who has undergone phacoemulsification with implantation of toric IOL (AcrySof IQ SN6AT9) after fixation of lens capsule with Cionni's capsular tension ring (CTR) for subluxated traumatic cataract with high astigmatism after deep anterior lamellar keratoplasty (DALK). He underwent right eye DALK for advanced keratoconus four years earlier. He had history of trauma one year later with displaced clear crystalline lens into  anterior chamber and graft dehiscence, which was repaired successfully. The graft survived, but patient developed cataract with subluxated lens, for which phacoemulsification with implantation of toric IOL was done. Serial  topography showed regular corneal astigmatism of -5.50 diopter (K 1 42.75 D @130°, K 2 48.25 D @40°). At 10-month follow-up, the patient has BCVA 20/30 with + 0.75 DS/- 1.75 DC @ 110°. The capsular bag is quite stable with well-centered IOL. Combination of Cionni's ring with toric IOL could be a good option to manage such complex cases.

  1. Combined special capsular tension ring and toric IOL implantation for management of post-DALK high regular astigmatism with subluxated traumatic cataract

    Directory of Open Access Journals (Sweden)

    Asim Kumar Kandar

    2014-01-01

    Full Text Available We report a case of 18-year-old male who has undergone phacoemulsification with implantation of toric IOL (AcrySof IQ SN6AT9 after fixation of lens capsule with Cionni′s capsular tension ring (CTR for subluxated traumatic cataract with high astigmatism after deep anterior lamellar keratoplasty (DALK. He underwent right eye DALK for advanced keratoconus four years earlier. He had history of trauma one year later with displaced clear crystalline lens into  anterior chamber and graft dehiscence, which was repaired successfully. The graft survived, but patient developed cataract with subluxated lens, for which phacoemulsification with implantation of toric IOL was done. Serial  topography showed regular corneal astigmatism of -5.50 diopter (K 1 42.75 D @130°, K 2 48.25 D @40°. At 10-month follow-up, the patient has BCVA 20/30 with + 0.75 DS/- 1.75 DC @ 110°. The capsular bag is quite stable with well-centered IOL. Combination of Cionni′s ring with toric IOL could be a good option to manage such complex cases.

  2. [Surgical solutions to luxation of the IOL--capsular bag--capsular tension ring complex].

    Science.gov (United States)

    Berthout, A; Turut, P; Taboureau, E; Denimal, F; Milazzo, S

    2007-02-01

    The spontaneous luxation of the intraocular lens-capsular bag-capsular tension ring complex is a serious but fortunately rare complication. The authors report a combined surgical procedure to reposition the complex in a patient who was operated on for bilateral lens subluxation 4 years before and whose enophthalmia made surgery difficult. Two surgical techniques can be considered to reposition the complex and avoid explantation. The McCannel modified stitch can capture the complex with the help of a transcorneal point and then a transscleral suture on the 12 o'clock meridian, despite the enophthalmia of the patient; the Moreno transscleral stitch. Both techniques suture the complex to the ciliary sulcus. Moreno's technique is easy and safe for the endothelium and must therefore be attempted first. In case of failure, the McCannel modified stitch remains a useful and satisfying procedure allowing transscleral fixation of the complex to the sulcus at the cost of a minimal corneal trauma.

  3. An elastic hollow cylinder under axial tension containing a crack and two rigid inclusions of ring shape

    OpenAIRE

    Artem, Hatice Seçil; Geçit, Mehmet Ruşen

    2002-01-01

    This paper is concerned with the fracture of an axisymmetric hollow cylindrical bar containing rigid inclusions. The cylinder is under the action of uniformly distributed axial tension applied at infinity. The bar contains a ring-shaped crack at the symmetry plane whose surfaces are free of tractions and two ring-shaped rigid inclusions with negligible thickness symmetrically located on both sides of the crack. It is assumed that the material of the cylinder is linearly elastic and isotropic....

  4. [Evaluation of the modified capsular tension ring in cases of traumatic lens subluxation].

    Science.gov (United States)

    Marques, Daniela Meira Villano; Marques, Frederico França; Cionni, Robert J; Osher, Robert Henry; Freitas, Lincoln Lemes

    2007-01-01

    To evaluate the behavior of the modified capsular tension ring (MCTR) in traumatic subluxated cataracts analyzing the visual acuity, centration of the capsular bag, pseudophacodonesis, postoperative follow-up and intra- and postoperative complications. Cincinnati Eye Institute, Cincinnati, Ohio, USA. Twenty-two eyes of 22 patients with traumatic loss of zonular support had phacoemulsification using PCIOL and MCTR implantation. The preoperative examination included best correct visual acuity (BCVA) and the presence or absence of phacodonesis, lens decentration and vitreous prolapse. The postoperative evaluation included BCVA, the presence of pseudophacodonesis, PCIOL centration, necessity of vitrectomy and other complications. 21 eyes (95.45%) had an improvement in BCVA. The preoperative examination disclosed phacodonesis in 11 eyes (50%) and no eye presented pseudophacodonesis in the postoperative period. Preoperatively, symptomatic decentration was presented by 10 eyes (45.45%) and 22 eyes (100%) had no decentration after surgery. The preoperative examination revealed vitreous prolapse in the anterior chamber in 9 eyes (40.90%). Vitrectomy was required in 11 eyes (50%). The use of the MCTR resulted in a good centration of the capsular bag and the PC IOL in 22 eyes with traumatic cataract and loss of zonular support.

  5. [Iris hooks and modified capsular tension ring for subluxation lens in patients with Marfan's syndrome].

    Science.gov (United States)

    Wu, Wen-Jie; Zheng, Dan-ying; Zheng, Ying-feng; Cai, Xiao-yu

    2007-02-01

    To evaluate clinical efficiency and safety of the iris hooks and modified capsular tension ring (MCTR) for the treatment of subluxation lens in patients with Marfan's syndrome. This study comprised 5 patients (7 eyes) with Marfan's syndrome and subluxation lens. After 3.2 mm clear cornea incision and continuous curvilinear capsulorhexis (CCC), 2 - 4 disposable nylon iris hooks were inserted through the stab incisions and placed in the capsulorhexis to support the capsule and enlarged the CCC. Following irrigation/aspiration, a MCTR with suture in its eyelet was placed in the capsule bag. After tightening and tying the suture of MCTR, the capsular bag was centered and fixed. A foldable AcrySof one-piece intraocular lens (IOL) was then placed in the capsule bag. Twelve months after the operation, the best corrected visual acuity was >/= 0.8 in six eyes and 0.7 in one eye. The scheimpflug images obtained from the Pentacam demonstrated that the IOL were well centered. UBM showed that all the MCTR and the haptics of the IOL were in the capsule bag, the eyelet of the MCTR was rested stably between the capsulorhexis margin and the iris. The retroillumination photograph indicated that only one eye had obvious posterior capsular opacification. No intraoperative and postoperative complications such as prolapse of vitreous and retina detachment was occurred. The iris hooks can provide excellent intraoperative capsule-lens stability and facilitate the manipulation during operation. MCTR allows additional suture fixation to the eye wall without damaging the capsular bag and maintains the long-term stability of the intraocular lens. Furthermore, MCTR is helpful for avoiding dislocation of the IOL due to progressive weakening of the zonular fibers in some patients and provides long-term safety.

  6. Development of indirect ring tension test for fracture characterization of asphalt mixtures

    Science.gov (United States)

    Zeinali Siavashani, Alireza

    Low temperature cracking is a major distress in asphalt pavements. Several test configurations have been introduced to characterize the fracture properties of hot mix (HMA); however, most are considered to be research tools due to the complexity of the test methods or equipment. This dissertation describes the development of the indirect ring tension (IRT) fracture test for HMA, which was designed to be an effective and user-friendly test that could be deployed at the Department of Transportation level. The primary advantages of this innovative and yet practical test include: relatively large fracture surface test zone, simplicity of the specimen geometry, widespread availability of the required test equipment, and ability to test laboratory compacted specimens as well as field cores. Numerical modeling was utilized to calibrate the stress intensity factor formula of the IRT fracture test for various specimen dimensions. The results of this extensive analysis were encapsulated in a single equation. To develop the test procedure, a laboratory study was conducted to determine the optimal test parameters for HMA material. An experimental plan was then developed to evaluate the capability of the test in capturing the variations in the mix properties, asphalt pavement density, asphalt material aging, and test temperature. Five plant-produced HMA mixtures were used in this extensive study, and the results revealed that the IRT fracture test is highly repeatable, and capable of capturing the variations in the fracture properties of HMA. Furthermore, an analytical model was developed based on the viscoelastic properties of HMA to estimate the maximum allowable crack size for the pavements in the experimental study. This analysis indicated that the low-temperature cracking potential of the asphalt mixtures is highly sensitive to the fracture toughness and brittleness of the HMA material. Additionally, the IRT fracture test data seemed to correlate well with the data from

  7. Estimation of fracture toughness and critical crack length of zircaloy pressure tube from ring tension test

    International Nuclear Information System (INIS)

    Chatterjee, S.; Anantharaman, S.; Balakrishnan, K.S.; Sriharsha, H.K.

    1999-09-01

    Transverse fracture, toughness data of zircaloy pressure tubes are needed for assuring leak-before-break, if any, during their in-reactor residence. These data are conventionally computed from burst tests and/or using compact tension specimens. A study was undertaken to derive fracture toughness of zircaloy in the temperature range ambient to 300 deg C, from the transverse tensile properties. The fracture toughness properties so derived were used to estimate the values of critical crack length of zircaloy pressure tubes in the above temperature range. (author)

  8. TRIDENT-CTR: a two-dimensional transport code for CTR applications

    International Nuclear Information System (INIS)

    Seed, T.J.

    1978-01-01

    TRIDENT-CTR is a two-dimensional x-y and r-z geometry multigroup neutral transport code developed at Los Alamos for toroidal calculations. The use of triangular finite elements gives it the geometric flexibility to cope with the nonorthogonal shapes of many toroidal designs of current interest in the CTR community

  9. Ectopic Expression of CsCTR1, a Cucumber CTR-Like Gene, Attenuates Constitutive Ethylene Signaling in an Arabidopsis ctr1-1 Mutant and Expression Pattern Analysis of CsCTR1 in Cucumber (Cucumis sativus

    Directory of Open Access Journals (Sweden)

    Beibei Bie

    2014-09-01

    Full Text Available The gaseous plant hormone ethylene regulates many aspects of plant growth, development and responses to the environment. Constitutive triple response 1 (CTR1 is a central regulator involved in the ethylene signal transduction pathway. To obtain a better understanding of this particular pathway in cucumber, the cDNA-encoding CTR1 (designated CsCTR1 was isolated from cucumber. A sequence alignment and phylogenetic analyses revealed that CsCTR1 has a high degree of homology with other plant CTR1 proteins. The ectopic expression of CsCTR1 in the Arabidopsis ctr1-1 mutant attenuates constitutive ethylene signaling of this mutant, suggesting that CsCTR1 indeed performs its function as negative regulator of the ethylene signaling pathway. CsCTR1 is constitutively expressed in all of the examined cucumber organs, including roots, stems, leaves, shoot apices, mature male and female flowers, as well as young fruits. CsCTR1 expression gradually declined during male flower development and increased during female flower development. Additionally, our results indicate that CsCTR1 can be induced in the roots, leaves and shoot apices by external ethylene. In conclusion, this study provides a basis for further studies on the role of CTR1 in the biological processes of cucumber and on the molecular mechanism of the cucumber ethylene signaling pathway.

  10. Distributed Workflow Service Composition Based on CTR Technology

    Science.gov (United States)

    Feng, Zhilin; Ye, Yanming

    Recently, WS-BPEL has gradually become the basis of a standard for web service description and composition. However, WS-BPEL cannot efficiently describe distributed workflow services for lacking of special expressive power and formal semantics. This paper presents a novel method for modeling distributed workflow service composition with Concurrent TRansaction logic (CTR). The syntactic structure of WS-BPEL and CTR are analyzed, and new rules of mapping WS-BPEL into CTR are given. A case study is put forward to show that the proposed method is appropriate for modeling workflow business services under distributed environments.

  11. Application of REDUCE-2 to the computation in CTR

    International Nuclear Information System (INIS)

    Tsunematsu, Toshihide; Kurita, Gen-ichi; Ninomiya, Hiromasa; Takeda, Tatsuoki

    1977-07-01

    Complicated analytical calculations in CTR were made with algebraic manipulation language REDUCE-2. Described as such are calculation of the coefficient matrix in mhd stability analysis by a variational method, calculation of metrics and equilibrium quantities in stability analysis by an initial-value problem, and calculation of the equilibrium magnetic field for positional control of the toroidal plasma. Algebraic manipulations proved to be highly useful in CTR. (auth.)

  12. Biochemical characterization of the human copper transporter Ctr1.

    Science.gov (United States)

    Lee, Jaekwon; Peña, Maria Marjorette O; Nose, Yasuhiro; Thiele, Dennis J

    2002-02-08

    The trace metal copper is an essential cofactor for a number of biological processes including mitochondrial oxidative phosphorylation, free radical detoxification, neurotransmitter synthesis and maturation, and iron metabolism. Consequently, copper transport at the cell surface and the delivery of copper to intracellular proteins are critical events in normal physiology. Little is known about the molecules and biochemical mechanisms responsible for copper uptake at the plasma membrane in mammals. Here, we demonstrate that human Ctr1 (hCtr1) is a component of the copper transport machinery at the plasma membrane. hCtr1 transports copper with high affinity in a time-dependent and saturable manner and is metal-specific. hCtr1-mediated (64)Cu transport is an energy-independent process and is stimulated by extracellular acidic pH and high K(+) concentrations. hCtr1 exists as a homomultimer at the plasma membrane in mammalian cells. This is the first report on the biochemical characterization of the human copper transporter hCtr1, which is important for understanding mechanisms for mammalian copper transport at the plasma membrane.

  13. Application of damage functions to CTR component fluence limit predictions

    International Nuclear Information System (INIS)

    Simons, R.L.; Doran, D.G.

    1975-01-01

    Material behavior observed under irradiation conditions in test reactors is not always directly applicable to the design of reactor components such as CTR first wall because of differences in the damage effectiveness of test reactor and service spectra. The interpolation and, under some conditions, extrapolation of material property change data from test conditions to different neutron spectra in service conditions can be accomplished using semi-empirical damage functions. The derivation and application of damage functions to CTR conditions is reviewed. Since limited amounts of data are available for applications to CTR design spectra, considerable attention is placed on the effectiveness of various available and proposed neutron sources in determining a damage function and subsequent fluence limit prediction. Neutron sources included in this study were EBR-II, HIFR, LAMPF (Be and Cu targets), high energy deuterons incident on Be (D-Be), and 14 MeV neutrons (D-T)

  14. Surface erosion phenomena in connection with CTR applications

    International Nuclear Information System (INIS)

    Kaminsky, M.; Das, S.K.

    1976-01-01

    The interaction of plasma radiations with the exposed surfaces of components of plasma devices and future controlled thermonuclear fusion reactors (CTR) can cause a variety of surface effects. In turn, such surface effects can cause (a) the release of plasma contaminants, and (b) the damage and erosion of the irradiated surfaces. The contamination of the plasma can have serious effects on plasma stability and on plasma temperature, and the surface erosion can seriously limit the lifetime of the irradiated components. At present, knowledge of surface erosion rates for the plasma parameters and materials envisioned in CTR applications is only fragmentary. To what extent the erosion rates will be affected by synergistic effects due to the simultaneous bombardment of surfaces by high fluxes of energetic particles of various types and by photons is almost completely unknown. A summary of some of the major surface erosion phenomena which have been identified as being important for CTR applications by using single irradiation sources (e.g., accelerators) will be given. A discussion of some potential solutions to reduce surface erosion will be included. The main features of a recently completed two component irradiation facility at ANL for CTR related surface studies will be described

  15. Molecular Characterization of CTR-type Copper Transporters in an Oceanic Diatom, Thalassiosira oceanica 1005

    Science.gov (United States)

    Kong, L.; Price, N. M.

    2016-02-01

    Copper is an essential micronutrient for phytoplankton growth because of its role as a redox cofactor in electron transfer proteins in photosynthesis and respiration, and a potentially limiting resource in parts of the open sea. Thalassiosira oceanica 1005 can grow at inorganic copper concentrations varying from 10 fmol/L to 10 nmol/L by regulating copper uptake across plasma membrane. Four putative CTR-type copper transporter genes (ToCTR1, ToCTR2, ToCTR3.1 and ToCTR3.2) were identified by BLASTP search against the T. oceanica genome. Predicted gene models were revised by assembled mRNA sequencing transcripts and updated gene models contained all conserved features of characterized CTR-type copper transporters. ToCTR3.1 and ToCTR3.2 may arise from one another by gene duplication as they shared a sequence similarity of 97.6% with a peptide insertion of 5 amino acids at N-terminus of ToCTR3.1. The expression of ToCTR1, ToCTR2 and ToCTR3.1/3.2 was upregulated in low copper concentrations, but only ToCTR3.1/3.2 showed a significant increase (2.5 fold) in copper-starved cells. Both ToCTR3.1 and ToCTR3.2 restored growth of a yeast double mutant, Saccharomyces cerevisiae ctrctr3Δ, in copper deficient medium. GFP-fused ToCTR expression showed that some ToCTR3.1 localized to the plasma membrane but a large portion was retained in the endoplasmic reticulum. Inefficient targeting of ToCTR3.1 to the yeast outer membrane may explain poorer growth compared to the Saccharomyces native ScCTR1 transformant. Thus, diatom CTR genes encoding CTR-type copper transporters show high-affinity copper uptake and their regulation may enable diatoms to survive in ocean environments containing a wide range of copper concentrations.

  16. Safety and effect of femtosecond laser-assisted cataract surgery combined with Cionni capsular tension ring implantation in the management of traumatic lens subluxation

    Directory of Open Access Journals (Sweden)

    Jia-Hui Chen

    2017-07-01

    Full Text Available AIM:To investigate the safety and effect of femtosecond laser-assisted cataract surgery with Cionni modified capsular tension ring(MCTRimplantation in the management of traumatic lens subluxation.METHODS: Totally 11 patients(11 eyeswith traumatic lens subluxation were divided into three groups according to the severity of lens dislocation, ranging from 90° to 120°(4 eyes, 120° to 180°(5 eyesand 180° to 270°(2 eyes. The contact LenSx femtosecond laser cataract surgery platform was applied to create the capsulotomy, prepare nuclear fragmentation and make corneal wound creation. Anterior vitrectomy was performed in some patients during the surgery. After capsular retractors insertion and phacoemulsification, the MCTR was inserted to the capsular bag and fixed to the sclera. Finally, the IOL was implanted into the capsular bag. Postoperative visual acuity, intra- and post-operative complications, anterior capsular opening, IOL and MCTR position and intraocular pressure(IOPwere assessed.RESULTS:The duration of follow-up was 2mo. All the operations were completed successfully. Five eyes underwent cataract surgery combined with anterior vitrectomy. Four eyes had been inserted with 2-eyelet MCTR and seven eyes with 1-eyelet MCTR. The best corrected visual acuity(BCVAafter operation was better than 0.5 in 4 eyes, between 0.3 and 0.5 in 3 eyes, between 0.1 and 0.3 in 3 eyes, and less than 0.1 in 1 eye. Compared with preoperative BCVA, the difference was statistically significant(PCONCLUSION:Femtosecond laser-assisted cataract surgery can improve the success rate of capsulorhexis, and reduce the difficulty of nuclear fragmentation. Femtosecond laser-assisted cataract surgery combined with MCTR implantation is an ideal surgical method for traumatic lens subluxation.

  17. Expression profiles of a MhCTR1 gene in relation to banana fruit ripening.

    Science.gov (United States)

    Hu, Huei-Lin; Do, Yi-Yin; Huang, Pung-Ling

    2012-07-01

    The banana (Musa spp.) is a typical climacteric fruit of high economic importance. The development of bananas from maturing to ripening is characterized by increased ethylene production accompanied by a respiration burst. To elucidate the signal transduction pathway involved in the ethylene regulation of banana ripening, a gene homologous to Arabidopsis CTR1 (constitutive triple response 1) was isolated from Musa spp. (Hsien Jin Chiao, AAA group) and designated as MhCTR1. MhCTR1 spans 11.5 kilobases and consists of 15 exons and 14 introns with consensus GT-AG nucleotides situated at their boundaries. MhCTR1 encodes a polypeptide of 805 amino acid residues with a calculated molecular weight of 88.6 kDa. The deduced amino acid sequence of MhCTR1 demonstrates 55%, 56% and 55% homology to AtCTR1, RhCTR1, and LeCTR1, respectively. MhCTR1 is expressed mostly in the mature green pulp and root organs. During fruit development MhCTR1 expression increases just before ethylene production rises. Moreover, MhCTR1 expression was detected mainly in the pulps at ripening stage 3, and correlated with the onset of peel yellowing, while MhCTR1 was constitutively expressed in the peels. MhCTR1 expression could be induced by ethylene treatment (0.01 μL L(-1)), and MhCTR1 expression decreased in both peel and pulp 24 h after treatment. Overall, changes observed in MhCTR1 expression in the pulp closely related to the regulation of the banana ripening process. Copyright © 2012. Published by Elsevier Masson SAS.

  18. LeCTR2, a CTR1-like protein kinase from tomato, plays a role in ethylene signalling, development and defence

    Science.gov (United States)

    Lin, Zhefeng; Alexander, Lucy; Hackett, Rachel; Grierson, Don

    2008-01-01

    Arabidopsis AtCTR1 is a Raf-like protein kinase that interacts with ETR1 and ERS and negatively regulates ethylene responses. In tomato, several CTR1-like proteins could perform this role. We have characterized LeCTR2, which has similarity to AtCTR1 and also to EDR1, a CTR1-like Arabidopsis protein involved in defence and stress responses. Protein–protein interactions between LeCTR2 and six tomato ethylene receptors indicated that LeCTR2 interacts preferentially with the subfamily I ETR1-type ethylene receptors LeETR1 and LeETR2, but not the NR receptor or the subfamily II receptors LeETR4, LeETR5 and LeETR6. The C-terminus of LeCTR2 possesses serine/threonine kinase activity and is capable of auto-phosphorylation and phosphorylation of myelin basic protein in vitro. Overexpression of the LeCTR2 N-terminus in tomato resulted in altered growth habit, including reduced stature, loss of apical dominance, highly branched inflorescences and fruit trusses, indeterminate shoots in place of determinate flowers, and prolific adventitious shoot development from the rachis or rachillae of the leaves. Expression of the ethylene-responsive genes E4 and chitinase B was upregulated in transgenic plants, but ethylene production and the level of mRNA for the ethylene biosynthetic gene ACO1 was unaffected. The leaves and fruit of transgenic plants also displayed enhanced susceptibility to infection by the fungal pathogen Botrytis cinerea, which was associated with much stronger induction of pathogenesis-related genes such as PR1b1 and chitinase B compared with the wild-type. The results suggest that LeCTR2 plays a role in ethylene signalling, development and defence, probably through its interactions with the ETR1-type ethylene receptors of subfamily I. PMID:18346193

  19. Heterodimerization of the prostaglandin E2 receptor EP2 and the calcitonin receptor CTR.

    Directory of Open Access Journals (Sweden)

    Shin Matsubara

    Full Text Available G protein-coupled receptors (GPCRs have been found to form heterodimers and modulate or fine-tune the functions of GPCRs. However, the involvement of GPCR heterodimerization and its functional consequences in gonadal tissues, including granulosa cells, have been poorly investigated, mainly due to the lack of efficient method for identification of novel GPCR heterodimers. In this paper, we identified a novel GPCR heterodimer between prostaglandin E2 (PGE2 receptor 2 (EP2 and calcitonin (CT receptor (CTR. High-resolution liquid chromatography (LC-tandem mass spectrometry (MS/MS of protease-digested EP2-coimmunoprecipitates detected protein fragments of CTR in an ovarian granulosa cell line, OV3121. Western blotting of EP2- and CTR-coimmunoprecipitates detected a specific band for EP2-CTR heterodimer. Specific heterodimerization between EP2 and CTR was also observed by fluorescence resonance energy transfer analysis in HEK293MSR cells expressing cyan- and yellow-fluorescent protein-fused EP2 and CTR, respectively. Collectively, these results provided evidence for heterodimerization between EP2 and CTR. Moreover, Ca2+ mobilization by CT was approximately 40% less potent in HEK293MSR cells expressing an EP2-CTR heterodimer, whereas cAMP production by EP2 or CT was not significantly altered compared with cells expressing EP2- or CTR alone. These functional analyses verified that CTR-mediated Ca2+ mobilization is specifically decreased via heterodimerization with EP2. Altogether, the present study suggests that a novel GPCR heterodimer, EP2-CTR, is involved in some functional regulation, and paves the way for investigation of novel biological roles of CTR and EP2 in various tissues.

  20. Chemical interactions of insulator materials in CTR environments

    International Nuclear Information System (INIS)

    Hoffman, J.G.

    1976-01-01

    The stringent demands for materials performance in an operational CTR power system require careful consideration and planning to avoid unacceptable deletorious interactions between components. Efforts have begun to identify potential problem areas and experiments are in progress to understand the fundamental aspects of these new materials problems. Two long-term experiments are in progress to study these interactions, specifically reactor irradiations of refractory metal/ceramic interfaces and the atomic hydrogen erosion problem. A high-purity polycrystalline alumina probe directly exposed to a deuterium plasma was examined to determine the effects of the plasma bombardment. Though the surface was altered through erosion or flash melting, the probe surface was intact and exhibited no signs of mechanical or electrical failure

  1. Tension Headache

    Science.gov (United States)

    ... your head Tenderness on your scalp, neck and shoulder muscles Tension headaches are divided into two main categories — ... that monitor and give you feedback on body functions such as muscle tension, heart rate and blood pressure. You then ...

  2. Annual report of the CTR Blanket Engineering research facility in 1994

    International Nuclear Information System (INIS)

    1995-09-01

    This is an annual report of the studies on Controlled Thermo-nuclear Reactor(CTR) Blanket Engineering which have been carried out in the Faculty of Engineering, the University of Tokyo, in FY 1994. This research facility on the CTR Blanket Engineering is located in the Nuclear Engineering Research Laboratory, the Tokai-mura branch of the Faculty of Engineering. (author)

  3. Annual report of the CTR Blanket Engineering research facility in 1996

    International Nuclear Information System (INIS)

    1998-02-01

    This is an annual report of the studies on Controlled Thermo-nuclear Reactor (CTR) Blanket Engineering which have been carried out in the Faculty of Engineering, the University of Tokyo, in FY 1996. This research facility on the CTR Blanket Engineering is located in the Nuclear Engineering Research Laboratory, the Tokai-mura branch of the Faculty of Engineering. (J.P.N.)

  4. Annual report of the CTR Blanket Engineering research facility in 1992

    International Nuclear Information System (INIS)

    1993-08-01

    This is an annual report of the studies on Controlled Thermo-nuclear Reactor (CTR) Blanket Engineering which have been carried out in the Faculty of Engineering, the University of Tokyo, in FY 1992. This research facility on the CTR Blanket Engineering is located in the Nuclear Engineering Research Laboratory, the Tokai-mura branch of the Faculty of Engineering. (J.P.N.)

  5. Cionni ring and in-the-bag intraocular lens implantation for subluxated lenses: a prospective case series.

    Science.gov (United States)

    Vasavada, Abhay R; Praveen, Mamidipudi R; Vasavada, Viraj A; Yeh, Ru-Yin; Srivastava, Samaresh; Koul, Archana; Trivedi, Rupal H

    2012-06-01

    To report the intraoperative performance and postoperative outcomes of the Cionni-modified capsule tension ring (CTR) implantation in eyes with subluxated lenses. Prospective, observational case series. This study was carried out at Iladevi Cataract & IOL Research Centre, Ahmedabad, India. The study population comprised 41 eyes with subluxated lenses that underwent lens extraction, capsular bag fixation with modified CTR, and in-the-bag single-piece AcrySof intraocular lens (IOL) implantation. Main outcome measures were intraoperative performance and postoperative best-corrected visual acuity (BCVA), IOL centration, and complications. The mean age was 29.46 ± 16.16 years (3-68 years). Mean extent of subluxation was 6.1 ± 1.0 clock hours. Preoperatively, vitreous was detected in the anterior chambers of 5 eyes (12.2%). Two-port anterior chamber vitrectomy was performed in 2 eyes. Mean follow-up was 45.8 ± 2.9 months. Mean preoperative BCVA was 0.66 ± 0.22 logMAR (35 eyes). Mean postoperative BCVA at final follow-up was 0.33 ± 0.21 logMAR (41 eyes) (P IOL decentration was noted and repositioning was required in 2 eyes. Posterior capsule opacification developed in 14 eyes (34.2%); 12 eyes (29.3%) required Nd:YAG capsulotomy. Other complications included cystoid macular edema in 1 eye (2.4%), posterior synechiae in 1 eye (2.4%), and retinal detachment in 1 eye (2.4%). In-the-bag implantation of a Cionni-modified CTR with IOL appears to be a safe option in eyes with subluxated cataract, ensuring a stable IOL with few complications. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Tension headache.

    Science.gov (United States)

    Ziegler, D K

    1978-05-01

    Headache is an extremely common symptom, and many headaches undoubtedly have a relationship to stressful situations. The clear definition, however, of a "tension headache" complex and its differentiation from migraine in some patients is difficult. The problems are in the identification of a specific headache pattern induced by stress or "tension" and the relationship of the symptom to involuntary contraction of neck and scalp muscles. Treatment consists of analgesics and occasionally mild tranquilizers. Psychotherapy consists of reassurance and often other supportive measures, including modification of life styles. Various feedback techniques have been reported of value, but their superiority to suggestion and hypnosis is still problematic.

  7. Interactions of cisplatin and the copper transporter CTR1 in human colon cancer cells.

    Science.gov (United States)

    Akerfeldt, Mia C; Tran, Carmen M-N; Shen, Clara; Hambley, Trevor W; New, Elizabeth J

    2017-07-01

    There is much interest in understanding the mechanisms by which platinum-based anticancer agents enter cells, and the copper transporter CTR1 has been the focus of many recent studies. While there is a clinical correlation between CTR1 levels and platinum efficacy, cellular studies have provided conflicting evidence relating to the relationship between cisplatin and CTR1. We report here our studies of the relationship between cisplatin and copper homeostasis in human colon cancer cells. While the accumulation of copper and platinum do not appear to compete with each other, we did observe that cisplatin perturbs CTR1 distribution within 10 min, a far shorter incubation time than commonly employed in cellular studies of cisplatin. Furthermore, on these short time-scales, cisplatin caused an increase in the cytoplasmic labile copper pool. While the predominant focus of studies to date has been on CTR1, these studies highlight the importance of investigating the interaction of cisplatin with other copper proteins.

  8. Summary of problems associated with primary damage and secondary defect aggregation under CTR irradiation conditions

    International Nuclear Information System (INIS)

    Hayns, M.R.

    1982-01-01

    Some of the important new quantities which need experimental verification and characterization to further our understanding of the irradiation damage processes in materials in CTR environments were highlighted. We have particularly emphasized the need to thoroughly understand the available simulation experiment conditions so that a proper correlation with the, as yet unobtainable, CTR conditions can be made. We have only focused upon the primary stages of the damage process and the nucleation of secondary defects. This should in no way be taken as implying that our understanding of the more basic quantities, such as diffusion in complex alloys, surface energies, stacking fault-energies, dislocation bias values, trap nature and binding energies, and phase stability (not segregation) is anywhere near adequate and further work is needed here as well as in the rather more exotic fields discussed in the body of the paper

  9. Overview of CTR-division control and data acquisition usage at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Chandler, G.I.; Klare, K.A.; Lillberg, J.W.; Wilkins, R.W.

    1979-01-01

    Computers have become an integral part of the control and data acquisition systems of several different fusion experiments in the CTR Division. These systems must (1) monitor and/or control approximately 200 to 1000 signals, (2) process from 40 to 250 diagnostic channels with a maximum plasma discharge repetition rate of once every five minutes, and (3) operate in an electrically noisy environment. Small to medium scale minicomputers interfaced to the experiment through CAMAC modules have been used to meet these requirements. System shielding and grounding have been given special consideration. These systems are also used for on-line data analysis and are linked to the local CTR network User Service Center where additional off-line analysis can be performed

  10. The design and analysis of integral assembly experiments for CTR neutronics

    International Nuclear Information System (INIS)

    Beynon, T.D.; Curtis, R.H.; Lambert, C.

    1978-01-01

    The use of simple-geometry integral assemblies of lithium metal or lithium compounds for the study of the neutronics of various CTR designs is considered and four recent experiments are analysed. The relatively long mean free path of neutrons in these assemblies produces significantly different design problems from those encountered in similar experiments for fission reactor design. By considering sensitivity profiles for various parameters it is suggested that experiments can be designed to be optimised for data adjustments. (author)

  11. Applications of controlled thermonuclear reactor (CTR) fusion power in the steel industry

    International Nuclear Information System (INIS)

    Jordan, R.K.; Steinberg, M.

    1975-03-01

    A review of the process and economics of basic steel production is presented for the purpose of indicating where CTR fusion energy may be applicable. The present conventional air blown blast furnace produces a relatively low Btu value top gas with limited usefulness. The industry consumes relatively large amounts of natural gas for reheating ingots, plates, etc. A concept is presented wherein oxygen is used in the blast furnace which would double the capacity of the furnace and produce a rich carbon monoxide gas stream useful as synthesis gas for methanol and ammonia production. A CTR supplying high energy radiation in a blanket would disproportionate carbon dioxide to carbon monoxide and oxygen which could be used at high temperatures in the blast furnace in place of an oxygen supply stream. Coke would be used in this scheme. In a second scheme the oxygen is separated from the disproportioned CO 2 stream and CO is used in a direct reduction furnace which is followed by an electric furnace to refine the reduced product. Other schemes include iron ore reduction with electrolytic hydrogen and the use of thermal energy for reforming coal with steam or CO 2 for production of reducing gas. The electrosmelting of scrap metal using CTR power could become an important operation in the future. A complex of steel, fertilizer, fuel and chemical production is presented. Steel capacity and power requirement data are presented and projected to the year 2020. (U.S.)

  12. Avaliação do uso do anel endocapsular modificado em casos de subluxação traumática do cristalino Evaluation of the modified capsular tension ring in cases of traumatic lens subluxation

    Directory of Open Access Journals (Sweden)

    Daniela Meira Villano Marques

    2007-10-01

    Full Text Available OBJETIVO: Avaliar o comportamento do anel modificado de tensão capsular em cataratas traumáticas com subluxação, analisando a acuidade visual, centração do saco capsular, pseudofacodonese, seguimento pós-operatório, e complicações intra e pós-operatórias. LOCAL: Cincinnati Eye Institute, Cincinnati, Ohio, USA. MÉTODOS: Vinte e dois olhos de 22 pacientes com perda traumática de suporte zonular foram submetidos à facoemulsificação utilizando lente intra-ocular de câmara posterior e o implante do anel capsular modificado. O exame pré-operatório incluiu melhor acuidade visual corrigida (MAVC, a presença ou ausência de facodonese, descentração do cristalino e prolapso vítreo. A avaliação pós-operatória incluiu MAVC, presença de pseudofacodonese, centração do implante, necessidade de vitrectomia e outras complicações. RESULTADOS: Vinte e um olhos (95,45% tiveram melhora da MAVC. O exame pré-operatório revelou facodonese em 11 olhos (50% e nenhum olho apresentou pseudofacodonese. No exame pré-operatório, a descentração sintomática estava presente em 10 olhos (45,45%. Todos os olhos apresentaram centração do complexo saco capsular/LIO no pós-operatório. Prolapso vítreo foi diagnosticado antes da cirurgia em 9 olhos (40,90% e a vitrectomia foi necessária em 11 olhos (50%. CONCLUSÃO: O uso do anel modificado de tensão capsular resultou em boa centração do complexo saco capsular/lente intra-ocular nos olhos estudados com catarata traumática e perda de suporte zonular.PURPOSE: To evaluate the behavior of the modified capsular tension ring (MCTR in traumatic subluxated cataracts analyzing the visual acuity, centration of the capsular bag, pseudophacodonesis, postoperative follow-up and intra- and postoperative complications. SETTING: Cincinnati Eye Institute, Cincinnati, Ohio, USA. METHODS: Twenty-two eyes of 22 patients with traumatic loss of zonular support had phacoemulsification using PCIOL and MCTR

  13. Tritium recovery and separation from CTR plasma exhausts and secondary containment atmospheres

    International Nuclear Information System (INIS)

    Forrester, R.C. III; Watson, J.S.

    1975-01-01

    Recent experimental successes have generated increased interest in the development of thermonuclear reactors as power sources for the future. This paper examines tritium containment problems posed by an operating CTR and sets forth some processing schemes currently being evaluated at the Oak Ridge National Laboratory. An appreciation of the CTR tritium management problem can best be realized by recalling that tritium production rates for various fission reactors range from 2 x 10 4 to 9 x 10 5 Ci/yr per 1000 MW(e). Present estimates of tritium production in a CTR blanket exceed 10 9 Ci/yr for the same level of power generation, and tritium process systems may handle 10 to 20 times that amount. Tritium's high permeability through most materials of construction at high temperatures makes secondary containment mandatory for most piping. Processing of these containment atmospheres will probably involve conversion of the tritium to a nonpermeating form (T 2 O) followed by trapping on conventional beds of desiccant material. In a similar fashion, all purge streams and process fluid vent gases will be subjected to tritium recovery prior to atmospheric release. Two tritium process systems will be required, one to recover tritium produced by breeding in the blanket and another to recover unburned tritium in the plasma exhaust. Plasma exhaust processing will be unconventional since the exhaust gas pressure will lie between 10 -3 and 10 -6 torr. Treatment of this gas stream will entail the removal of small quantities of protium and helium from a much larger deuterium-tritium mixture which will be recycled. (U.S.)

  14. Regulation of copper-dependent endocytosis and vacuolar degradation of the yeast copper transporter, Ctr1p, by the Rsp5 ubiquitin ligase.

    Science.gov (United States)

    Liu, Jingxuan; Sitaram, Anand; Burd, Christopher G

    2007-10-01

    The Saccharomyces cerevisiae high-affinity copper transporter, Ctr1p, mediates cellular uptake of Cu(I). We report that when copper (50 microm CuSO(4)) is added to the growth medium of copper-starved cells, Ctr1p is rapidly internalized by endocytosis, delivered to the lumen of the lysosome-like vacuole and slowly degraded by vacuolar proteases. Through analysis of the trafficking and degradation of Ctr1p mutants, two lysine residues in the C-terminal cytoplasmic tail of Ctr1p, Lys340 and Lys345, were found to be critical for copper-dependent endocytosis and degradation. In response to copper addition, Ctr1p was found to be ubiquitylated and a mutation in the Rsp5 ubiquitin ligase largely abolished ubiquitylation, endocytosis and degradation. In a strain lacking the Rsp5p accessory factors Bul1p and Bul2p, endocytosis and degradation of Ctr1p-green fluorescent protein were substantially diminished. Surprisingly, a Ctr1p mutant that lacks Lys340 and Lys345 was still ubiquitylated in a copper-dependent manner, indicating that ubiquitylation of Ctr1p on other sites is insufficient to drive copper-dependent endocytosis and degradation. This study demonstrates that copper regulates turnover of Ctr1p by stimulating Rsp5p-dependent endocytosis and degradation of Ctr1p in the vacuole.

  15. Helium embrittlement of CTR materials simulated by ions implantation and hot isostatic pressing of metal powders

    International Nuclear Information System (INIS)

    Fleischer, L.R.; Spitznagel, J.A.; Choyke, W.J.

    1976-01-01

    Helium embrittlement is currently considered a limitation on the lifetimes of CTR structures exposed to high energy neutrons. The phenomenon has been observed in fast fission reactor irradiated materials and has been studied in helium ion bombarded foil samples. In this study, helium ions were implanted in stainless steel and refractory metal alloy powder particles. The 150 keV ion energies used require particle size distributions with mean particle diameters of about 3 μm to get a suitably homogeneous initial distribution of helium atoms. The helium implanted powders were consolidated by hot isostatic pressing; the helium remained in solid solution. Subsequent thermomechanical processing permitted the preparation of tensile specimens with controlled helium bubble distributions. In general, grain boundary migration concentrated helium bubbles on the boundaries, while conditions favoring stationary boundaries allowed intragranular bubble nucleation on dislocations. It remains to be seen whether the distributions available through these processes are representative of those that will be generated in situ by (n,α) reactions in CTR neutron spectra. Specimens for bulk properties measurements prepared in this way are most suitable for study of helium embrittlement as an isolated effect. Many of the constraints encountered in other sample preparation methods are mitigated

  16. Mechanism of cytokinetic contractile ring constriction in fission yeast.

    Science.gov (United States)

    Stachowiak, Matthew R; Laplante, Caroline; Chin, Harvey F; Guirao, Boris; Karatekin, Erdem; Pollard, Thomas D; O'Shaughnessy, Ben

    2014-06-09

    Cytokinesis involves constriction of a contractile actomyosin ring. The mechanisms generating ring tension and setting the constriction rate remain unknown because the organization of the ring is poorly characterized, its tension was rarely measured, and constriction is coupled to other processes. To isolate ring mechanisms, we studied fission yeast protoplasts, in which constriction occurs without the cell wall. Exploiting the absence of cell wall and actin cortex, we measured ring tension and imaged ring organization, which was dynamic and disordered. Computer simulations based on the amounts and biochemical properties of the key proteins showed that they spontaneously self-organize into a tension-generating bundle. Together with rapid component turnover, the self-organization mechanism continuously reassembles and remodels the constricting ring. Ring constriction depended on cell shape, revealing that the ring operates close to conditions of isometric tension. Thus, the fission yeast ring sets its own tension, but other processes set the constriction rate. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Skin tension related to tension reduction sutures.

    Science.gov (United States)

    Hwang, Kun; Kim, Han Joon; Kim, Kyung Yong; Han, Seung Ho; Hwang, Se Jin

    2015-01-01

    The aim of this study was to compare the skin tension of several fascial/subcutaneous tensile reduction sutures. Six upper limbs and 8 lower limbs of 4 fresh cadavers were used. At the deltoid area (10 cm below the palpable acromion) and lateral thigh (midpoint from the palpable greater trochanter to the lateral border of the patella), and within a 3 × 6-cm fusiform area of skin, subcutaneous tissue defects were created. At the midpoint of the defect, a no. 5 silk suture was passed through the dermis at a 5-mm margin of the defect, and the defect was approximated. The initial tension to approximate the margins was measured using a tensiometer.The tension needed to approximate skin without any tension reduction suture (S) was 6.5 ± 4.6 N (Newton). The tensions needed to approximate superficial fascia (SF) and deep fascia (DF) were 7.8 ± 3.4 N and 10.3 ± 5.1 N, respectively. The tension needed to approximate the skin after approximating the SF was 4.1 ± 3.4 N. The tension needed to approximate the skin after approximating the DF was 4.9 ± 4.0 N. The tension reduction effect of approximating the SF was 38.8 ± 16.4% (2.4 ± 1.5 N, P = 0.000 [ANOVA, Scheffé]). The tension reduction effect of approximating the DF was 25.2% ± 21.9% (1.5 ± 1.4 N, P = 0.001 [ANOVA, Scheffé]). The reason for this is thought to be that the SF is located closely to the skin unlike the DF. The results of this study might be a basis for tension reduction sutures.

  18. Characterization of Ctr family genes and the elucidation of their role in the life cycle of Neurospora crassa.

    Science.gov (United States)

    Korripally, Premsagar; Tiwari, Anand; Haritha, Adhikarla; Kiranmayi, Patnala; Bhanoori, Manjula

    2010-03-01

    Transcriptional analysis using qRT-PCR of 62 metal ion transporters during conidial germination of Neurospora crassa showed a significant up regulation of a hypothetical copper transporter gene, tcu-1, that belongs to the Ctr family. Herein we characterised the Ctr family genes (tcu-1, tcu-2 and tcu-3) and deciphered their role in various developmental phases of the N. crassa life cycle. Cross complementation assays in copper uptake mutant of Saccharomyces cerevisiae revealed that tcu-1, tcu-2 and tcu-3 are functional homologs of S. cerevisiae copper transporters. Expression studies of Ctr family members in various developmental phases of N. crassa showed differential expression pattern for high-affinity copper transporter, TCU1. Functional analysis of their gene knockout mutants showed that tcu-1 is essential for saprophytic conidial germination, vegetative growth and perithecia development under copper limited conditions while conidiation remained unaffected. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  19. Cloning and characterisation of two CTR1-like genes in Cucurbita pepo: regulation of their expression during male and female flower development.

    Science.gov (United States)

    Manzano, Susana; Martínez, Cecilia; Gómez, Pedro; Garrido, Dolores; Jamilena, Manuel

    2010-12-01

    Ethylene is an essential regulator of flower development in Cucurbita pepo, controlling the sexual expression, and the differentiation and maturation of floral organs. To study the action mechanism of ethylene during the male and female flower development, we have identified two CTR1 homologues from C. pepo, CpCTR1 and CpCTR2, and analysed their expressions during female and male flower development and in response to external treatments with ethylene. CpCTR1 and CpCTR2 share a high homology with plant CTR1-like kinases, but differ from other related kinases such as the Arabidopsis EDR1 and the tomato LeCTR2. The C-terminal ends of both CpCTR1 and CpCTR2 have all the conserved motifs of Ser/Thr kinase domains, including the ATP-binding signature and the protein kinase active site consensus sequence, which suggests that CpCTR1 and CpCTR2 could have the same function as CTR1 in ethylene signalling. The transcripts of both genes were detected in different organs of the plant, including roots, leaves and shoots, but were mostly accumulated in mature flowers. During the development of male and female flowers, CpCTR1 and CpCTR2 expressions were concomitant with ethylene production, which indicates that both genes could be upregulated by ethylene, at least in flowers. Moreover, external treatments with ethylene, although did not alter the expression of these two genes in seedlings and leaves, were able to upregulate their expression in flowers. In the earlier stages of flower development, when ethylene production is very low, the expression of CpCTR1 and CpCTR2 is higher in male floral organs, which agrees with the role of these genes as negative regulators of ethylene signalling, and explain the lower ethylene sensitivity of male flowers in comparison with female flowers. The function of the upregulation of these two genes in later stages of female flower development, when the production of ethylene is also increased, is discussed.

  20. Reactor vessel stud tensioner

    International Nuclear Information System (INIS)

    Malandra, L.J.; Beer, R.W.; Salton, R.B.; Spiegelman, S.R.; Cognevich, M.L.

    1982-01-01

    A quick-acting stud tensioner, for facilitating the loosening or tightening of a stud nut on a reactor vessel stud, has gripper jaws which when the tensioner is lowered into engagement with the upper end of the stud are moved inwards to grip the upper end and which when the tensioner is lifted move outward to release the upper end. (author)

  1. 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.

  2. Development and evaluation of cryosorption pump and cryotrapping pump for CTR applications

    International Nuclear Information System (INIS)

    Kuribayashi, S.; Ota, H.; Sato, H.

    1986-01-01

    In order to obtain the engineering data to design compound cryopump for CTR, the authors tested the cryosorption pump and cryotrapping pump. The cryosorption panel was consisted of coconut charcoal metallically bonded to 4.2K cryopanel by brazing. The initial pumping speed of helium of cryosorption pump was found to be ≅2.2 iota/scm/sup 2/. The speed dropped off with loading (about 8 Torr iota/cm/sup 2/) to 1.5 iota/scm/sup 2/. The initial helium pumping speed of the 4.2K cryotrapping pump by argon spray was found to be ≅6 iota/scm/sup 2/. The speed, however, dropped off with loading (≅0.3 Torr iota/cm/sup 2/) to less than 5%. These results indicate that the cryosorption pump by coconut charcoal is superior to the cryotrapping pump, because the capacity of the former is larger than the latter

  3. EGCG Enhances Cisplatin Sensitivity by Regulating Expression of the Copper and Cisplatin Influx Transporter CTR1 in Ovary Cancer.

    Directory of Open Access Journals (Sweden)

    Xuemin Wang

    Full Text Available Cisplatin is one of the first-line platinum-based chemotherapeutic agents for treatment of many types of cancer, including ovary cancer. CTR1 (copper transporter 1, a transmembrane solute carrier transporter, has previously been shown to increase the cellular uptake and sensitivity of cisplatin. It is hypothesized that increased CTR1 expression would enhance the sensitivity of cancer cells to cisplatin (cDDP. The present study demonstrates for the first time that (--epigallocatechin-3-gallate (EGCG, a major polyphenol from green tea, can enhance CTR1 mRNA and protein expression in ovarian cancer cells and xenograft mice. EGCG inhibits the rapid degradation of CTR1 induced by cDDP. The combination of EGCG and cDDP increases the accumulation of cDDP and DNA-Pt adducts, and subsequently enhances the sensitivity of ovarian cancer SKOV3 and OVCAR3 cells to the chemotherapeutic agent. In the OVCAR3 ovarian cancer xenograft nude mice model, the combination of the lower concentration of cDDP and EGCG strongly repressed the tumor growth and exhibited protective effect on the nephrotoxicity induced by cisplatin. Overall, these findings uncover a novel chemotherapy mechanism of EGCG as an adjuvant for the treatment of ovarian cancer.

  4. Identification and functional characterization of the Lactococcus lactis CodY-regulated branched-chain amino acid permease BcaP (CtrA)

    NARCIS (Netherlands)

    den Hengst, CD; Groeneveld, M; Kuipers, OP; Kok, J; Hengst, Chris D. den

    Transcriptome analyses have previously revealed that a gene encoding the putative amino acid transporter CtrA (YhdG) is one of the major targets of the pleiotropic regulator CodY in Lactococcus lactis and Bacillus subtilis. The role of ctrA in L. lactis was further investigated with respect to both

  5. Planetary Rings

    Science.gov (United States)

    Tiscareno, Matthew S.

    Planetary rings are the only nearby astrophysical disks and the only disks that have been investigated by spacecraft (especially the Cassini spacecraft orbiting Saturn). Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 10- 7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close range and in real time in planetary rings.We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The A, B, and C rings of Saturn, plus the Cassini Division, comprise our solar system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are found both at Uranus (where they comprise the main rings entirely) and at Saturn (where they are embedded in the broad disk) and are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty rings, likely generated by embedded source bodies, are surprisingly found to sport azimuthally confined arcs at Neptune, Saturn, and Jupiter. Finally, every known ring system includes a substantial component of diffuse dusty rings.Planetary rings have shown themselves to be useful as detectors of planetary processes around them, including the planetary magnetic field and interplanetary impactors as well as the gravity of nearby perturbing moons. Experimental rings science has made great progress in recent decades, especially numerical simulations of self-gravity wakes and other processes but also laboratory investigations of coefficient of restitution and spectroscopic ground truth. The age of self-sustained ring systems is a matter of

  6. Relative contribution of CTR1 and DMT1 in copper transport by the blood–CSF barrier: Implication in manganese-induced neurotoxicity

    International Nuclear Information System (INIS)

    Zheng, Gang; Chen, Jingyuan; Zheng, Wei

    2012-01-01

    The homeostasis of copper (Cu) in the cerebrospinal fluid (CSF) is partially regulated by the Cu transporter-1 (CTR1) and divalent metal transporter-1 (DMT1) at the blood–CSF barrier (BCB) in the choroid plexus. Data from human and animal studies suggest an increased Cu concentration in blood, CSF, and brains following in vivo manganese (Mn) exposure. This study was designed to investigate the relative role of CTR1 and DMT1 in Cu transport under normal or Mn-exposed conditions using an immortalized choroidal Z310 cell line. Mn exposure in vitro resulted in an increased cellular 64 Cu uptake and the up-regulation of both CTR1 and DMT1. Knocking down CTR1 by siRNA counteracted the Mn-induced increase of 64 Cu uptake, while knocking down DMT1 siRNA resulted in an increased cellular 64 Cu uptake in Mn-exposed cells. To distinguish the roles of CTR1 and DMT1 in Cu transport, the Z310 cell-based tetracycline (Tet)-inducible CTR1 and DMT1 expression cell lines were developed, namely iZCTR1 and iZDMT1 cells, respectively. In iZCTR1 cells, Tet induction led to a robust increase (25 fold) of 64 Cu uptake with the time course corresponding to the increased CTR1. Induction of DMT1 by Tet in iZDMT1 cells, however, resulted in only a slight increase of 64 Cu uptake in contrast to a substantial increase in DMT1 mRNA and protein expression. These data indicate that CTR1, but not DMT1, plays an essential role in transporting Cu by the BCB in the choroid plexus. Mn-induced cellular overload of Cu at the BCB is due, primarily, to Mn-induced over-expression of CTR1. -- Highlights: ► This study compares the relative role of CTR1 and DMT1 in Cu transport by the BCB. ► Two novel tetracycline-inducible CTR1 and DMT1 expression cell lines are created. ► CTR1, but not DMT1, plays an essential role in transporting Cu by the BCB. ► Mn-induced cellular Cu overload is due to its induction of CTR1 rather than DMT1. ► Induction of CTR1 by Mn in the BCB contributes to an elevated Cu

  7. Relative contribution of CTR1 and DMT1 in copper transport by the blood–CSF barrier: Implication in manganese-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Gang [School of Health Sciences, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi' an, Shanxi 710032 (China); Chen, Jingyuan [Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi' an, Shanxi 710032 (China); Zheng, Wei, E-mail: wzheng@purdue.edu [School of Health Sciences, Purdue University, West Lafayette, Indiana 47907 (United States)

    2012-05-01

    The homeostasis of copper (Cu) in the cerebrospinal fluid (CSF) is partially regulated by the Cu transporter-1 (CTR1) and divalent metal transporter-1 (DMT1) at the blood–CSF barrier (BCB) in the choroid plexus. Data from human and animal studies suggest an increased Cu concentration in blood, CSF, and brains following in vivo manganese (Mn) exposure. This study was designed to investigate the relative role of CTR1 and DMT1 in Cu transport under normal or Mn-exposed conditions using an immortalized choroidal Z310 cell line. Mn exposure in vitro resulted in an increased cellular {sup 64}Cu uptake and the up-regulation of both CTR1 and DMT1. Knocking down CTR1 by siRNA counteracted the Mn-induced increase of {sup 64}Cu uptake, while knocking down DMT1 siRNA resulted in an increased cellular {sup 64}Cu uptake in Mn-exposed cells. To distinguish the roles of CTR1 and DMT1 in Cu transport, the Z310 cell-based tetracycline (Tet)-inducible CTR1 and DMT1 expression cell lines were developed, namely iZCTR1 and iZDMT1 cells, respectively. In iZCTR1 cells, Tet induction led to a robust increase (25 fold) of {sup 64}Cu uptake with the time course corresponding to the increased CTR1. Induction of DMT1 by Tet in iZDMT1 cells, however, resulted in only a slight increase of {sup 64}Cu uptake in contrast to a substantial increase in DMT1 mRNA and protein expression. These data indicate that CTR1, but not DMT1, plays an essential role in transporting Cu by the BCB in the choroid plexus. Mn-induced cellular overload of Cu at the BCB is due, primarily, to Mn-induced over-expression of CTR1. -- Highlights: ► This study compares the relative role of CTR1 and DMT1 in Cu transport by the BCB. ► Two novel tetracycline-inducible CTR1 and DMT1 expression cell lines are created. ► CTR1, but not DMT1, plays an essential role in transporting Cu by the BCB. ► Mn-induced cellular Cu overload is due to its induction of CTR1 rather than DMT1. ► Induction of CTR1 by Mn in the BCB

  8. Copper deprivation modulates CTR1 and CUP1 expression and enhances cisplatin cytotoxicity in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kommuguri, Upendra Nadh; Bodiga, Sreedhar; Sankuru, Suneetha; Bodiga, Vijaya Lakshmi

    2012-01-01

    Saccharomyces cerevisiae has been established as a model system for cancer studies, due to the widely conserved family of genes involved in cell cycle progression, proliferation and apoptosis. In the current study, we sought to determine whether copper deprivation modulates sensitivity of yeast to cisplatin. Yeast cultures grown in low copper medium and exposed to bathocuproiene disulfate (BCS) resulted in significant reduction of intracellular copper. We report here that low copper medium rendered BY4741 hypersensitive to cisplatin (CDDP). Yeast grown in low copper medium exhibited ∼2.0 fold enhanced cytotoxicity in survival and colony-forming ability, compared to copper adequate control cells grown in YPD. The effect of copper restriction on CDDP sensitivity appeared to be associated with the up regulation of CTR1, facilitating enhanced uptake and accumulation of CDDP. Also, CDDP further lowered copper deprivation-induced changes in CUP1 metallothionein levels, SOD activity and GSH levels. These changes were associated with increased protein oxidation and lipid peroxidation induced by CDDP. These results thus suggest that cisplatin cytotoxicity is potentiated under low copper conditions due to enhanced uptake and accumulation of cisplatin and also in part due to lowered antioxidant defense and increased oxidative stress imposed by copper deprivation. Copyright © 2011 Elsevier GmbH. All rights reserved.

  9. Storage rings

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, Gerald K.

    1963-04-15

    The development of storage rings is discussed. Advantages of such devices are pointed out as well as their limits, requirements, and design and fabrication problems. Information gained by the operation of small electron storage rings is included, and three experiments are proposed for colliding-beam facilities. (D.C.W.)

  10. 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.

  11. Tensions in Distributed Leadership

    Science.gov (United States)

    Ho, Jeanne; Ng, David

    2017-01-01

    Purpose: This article proposes the utility of using activity theory as an analytical lens to examine the theoretical construct of distributed leadership, specifically to illuminate tensions encountered by leaders and how they resolved these tensions. Research Method: The study adopted the naturalistic inquiry approach of a case study of an…

  12. The CckA-ChpT-CtrA phosphorelay system is regulated by quorum sensing and controls flagellar motility in the marine sponge symbiont Ruegeria sp. KLH11.

    Directory of Open Access Journals (Sweden)

    Jindong Zan

    Full Text Available Bacteria respond to their environment via signal transduction pathways, often two-component type systems that function through phosphotransfer to control expression of specific genes. Phosphorelays are derived from two-component systems but are comprised of additional components. The essential cckA-chpT-ctrA phosphorelay in Caulobacter crescentus has been well studied and is important in orchestrating the cell cycle, polar development and flagellar biogenesis. Although cckA, chpT and ctrA homologues are widespread among the Alphaproteobacteria, relatively few is known about their function in the large and ecologically significant Roseobacter clade of the Rhodobacterales. In this study the cckA-chpT-ctrA system of the marine sponge symbiont Ruegeria sp. KLH11 was investigated. Our results reveal that the cckA, chpT and ctrA genes positively control flagellar biosynthesis. In contrast to C. crescentus, the cckA, chpT and ctrA genes in Ruegeria sp. KLH11 are non-essential and do not affect bacterial growth. Gene fusion and transcript analyses provide evidence for ctrA autoregulation and the control of motility-related genes. In KLH11, flagellar motility is controlled by the SsaRI system and acylhomoserine lactone (AHL quorum sensing. SsaR and long chain AHLs are required for cckA, chpT and ctrA gene expression, providing a regulatory link between flagellar locomotion and population density in KLH11.

  13. Model calculations as one means of satisfying the neutron cross-section requirements of the CTR program

    International Nuclear Information System (INIS)

    Gardner, D.G.

    1975-01-01

    A large amount of cross section and spectral information for neutron-induced reactions will be required for the CTR design program. To undertake to provide the required data through a purely experimental measurement program alone may not be the most efficient way of attacking the problem. It is suggested that a preliminary theoretical calculation be made of all relevant reactions on the dozen or so elements that now seem to comprise the inventory of possible construction materials to find out which are actually important, and over what energy ranges they are important. A number of computer codes for calculating cross sections for neutron induced reactions have been evaluated and extended. These will be described and examples will be given of various types of calculations of interest to the CTR program. (U.S.)

  14. Copper-dependent degradation of the Saccharomyces cerevisiae plasma membrane copper transporter Ctr1p in the apparent absence of endocytosis.

    OpenAIRE

    Ooi, C E; Rabinovich, E; Dancis, A; Bonifacino, J S; Klausner, R D

    1996-01-01

    The cell surface protein repertoire needs to be regulated in response to changes in the extracellular environment. In this study, we investigate protein turnover of the Saccharomyces cerevisiae plasma membrane copper transporter Ctr1p, in response to a change in extra-cellular copper levels. As Ctr1p mediates high affinity uptake of copper into the cell, modulation of its expression is expected to be involved in copper homeostasis. We demonstrate that Ctr1p is a stable protein when cells are ...

  15. Determinantal rings

    CERN Document Server

    Bruns, Winfried

    1988-01-01

    Determinantal rings and varieties have been a central topic of commutative algebra and algebraic geometry. Their study has attracted many prominent researchers and has motivated the creation of theories which may now be considered part of general commutative ring theory. The book gives a first coherent treatment of the structure of determinantal rings. The main approach is via the theory of algebras with straightening law. This approach suggest (and is simplified by) the simultaneous treatment of the Schubert subvarieties of Grassmannian. Other methods have not been neglected, however. Principal radical systems are discussed in detail, and one section is devoted to each of invariant and representation theory. While the book is primarily a research monograph, it serves also as a reference source and the reader requires only the basics of commutative algebra together with some supplementary material found in the appendix. The text may be useful for seminars following a course in commutative ring theory since a ...

  16. 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.

  17. Vascular ring

    Science.gov (United States)

    ... trachea) and esophagus can lead to breathing and digestive problems. The more the ring presses down, the more severe the symptoms will be. Breathing problems may include: ... Digestive symptoms are rare, but may include: Choking Difficulty ...

  18. Strings with zero tension

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, R.; Barcelos-Neto, J.

    1988-05-01

    We describe bosonic strings by using a kind of Lagrangian compatible with the zero tension limit. The work is developed on an extended configuration space and the quantization is carried out with details.

  19. Parachute Cord Tension Sensor

    Data.gov (United States)

    National Aeronautics and Space Administration — To design and fabricate a light weight (few oz), very small (~2 inch length) parachute cord tension sensor demonstrator device.A major challenge for the CPAS (The...

  20. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  1. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  2. Salinity-dependent copper accumulation in the guppy Poecilia vivipara is associated with CTR1 and ATP7B transcriptional regulation.

    Science.gov (United States)

    da Silva, Evelise Sampaio; Abril, Sandra Isabel Moreno; Zanette, Juliano; Bianchini, Adalto

    2014-07-01

    Copper (Cu) accumulation and regulation of key-genes involved in Cu homeostasis were evaluated in freshwater- and saltwater-acclimated guppies Poecilia vivipara. Fish were exposed (96h) to environmentally relevant concentrations of dissolved Cu (0, 5.0, 9.0 and 20.0μg/L). In freshwater guppies, gill and liver Cu accumulation was dependent on Cu concentration in the exposure medium. In saltwater guppies, this dependence was observed only in the gut. These findings indicate that Cu accumulation was salinity- and tissue-dependent. Key genes involved in Cu metabolism were sequenced for the first time in P. vivipara. Transcripts coding for the high-affinity copper transporter (CTR1) and copper-transporting ATPase (ATP7B) were identified using polymerase chain reaction (PCR) and gene sequencing. The full-length CTR1 open reading frame (1560bp) and a partial ATP7B (690bp) were discovered. Predicted amino acid sequences shared high identities with the CTR1 of Fundulus heteroclitus (81%) and the ATP7B of Sparus aurata (87%). Basal transcriptional levels addressed by RT-qPCR in control fish indicate that CTR1 and ATP7B was highly transcribed in liver of freshwater guppies while CTR1 was highly transcribed in gut of saltwater guppies. This could explain the higher Cu accumulation observed in liver of freshwater guppies and in gut of saltwater guppies, because CTR1 is involved in Cu uptake. Reduced gill mRNA expression of CTR1 was observed in freshwater guppies exposed to 20.0μg/L Cu and in saltwater guppies exposed to 5.0μg/L Cu. In turn, reduced mRNA expression of gut ATP7B was observed in freshwater and salt water guppies exposed to 9.0 and 20.0μg/L Cu. Liver CTR1 and ATP7B transcription were not affected by Cu exposure. These findings suggest that gill CTR1 and gut ATP7B are down-regulated to limit Cu absorption after exposure to dissolved Cu, while liver CTR1 and ATP7B levels are maintained to allow Cu storage and detoxification. In conclusion, findings reported here

  3. 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

  4. 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.

  5. The effect of clamping a tensioned wire: implications for the Ilizarov external fixation system.

    Science.gov (United States)

    Watson, M A; Mathias, K J; Maffulli, N; Hukins, D W L

    2003-01-01

    This study demonstrates that clamping a tensioned wire can cause a reduction in wire tension. Tension (about 1275 N) was applied to a wire that was subsequently clamped, using cannulated bolts, to the steel half-ring of an Ilizarov external fixator. The tension in the wire was monitored before, during and after clamping. The apparatus was disassembled and the deformations in the wire caused by the clamps were measured. This experiment was repeated 15 times. When the wire was clamped to the frame, the wire tension was reduced by 22 +/- 7 per cent (mean +/- standard deviation, SD). The drop in wire tension was linearly correlated (r = 0.96; p toothpaste from a tube) and so reduce its tension during fixator assembly. To assess the magnitude of this effect in the clinical situation, the FE model analysis was repeated to replicate clamping a 1.8-mm-diameter wire to a 180-mm-diameter steel Ilizarov ring component. The analysis showed that for these conditions the tension reduced by 8-29 per cent. The results of this study highlight a general engineering problem: how can a tensioned wire be secured to a structure without an appreciable loss of tension? If the performance of the structure depends on the wire tension, this performance will change when the wire is secured.

  6. 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

  7. Transcriptional regulation of ethylene receptor and CTR genes involved in ethylene-induced flower opening in cut rose (Rosa hybrida) cv. Samantha.

    Science.gov (United States)

    Ma, Nan; Tan, Hui; Liu, Xiaohui; Xue, Jingqi; Li, Yunhui; Gao, Junping

    2006-01-01

    In this work, the effect of ethylene on flower opening of cut rose (Rosa hybrida) cv. Samantha was studied. However, although ethylene hastened the process of flower opening, 1-MCP (1-methylcyclopropene), an ethylene action inhibitor, impeded it. Ethylene promoted ethylene production in petals, but 1-MCP did not inhibit this process. Of the four ethylene biosynthetic genes tested, Rh-ACS1 and Rh-ACS2 were undetectable; Rh-ACS3 and Rh-ACO1 expression was enhanced by ethylene slightly and greatly, respectively. However, their mRNA amounts were not inhibited by 1-MCP compared with controls. Expression of seven signalling component genes was also studied, including three ethylene receptors (Rh-ETR1, Rh-ETR3, and Rh-ETR5), two CTRs (Rh-CTR1 and Rh-CTR2), and two transcription factors (Rh-EIN3-1 and Rh-EIN3-2). Transcripts of Rh-ETR5, Rh-EIN3-1, and Rh-EIN3-2 were accumulated in a constitutive manner and had no or little response to ethylene or 1-MCP, while transcript levels of Rh-ETR1 and Rh-CTR1 were substantially elevated by ethylene, and those of Rh-ETR3 and Rh-CTR2 were greatly enhanced by ethylene; 1-MCP reduced all the four genes to levels much less than those in control flowers. These results show that ethylene triggers physiological responses related to flower opening in cut rose cv. Samantha, and that continued ethylene perception results in flower opening. Ethylene may regulate flower opening mainly through expression of two ethylene receptor genes (Rh-ETR1 and Rh-ETR3) and two CTR (Rh-CTR1 and Rh-CTR2) genes.

  8. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta...

  9. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta block...

  10. SCR series switch and impulse crowbar at the Lawrence Berkeley Laboratory for CTR neutral beam source development

    International Nuclear Information System (INIS)

    Franck, J.V.; Arthur, A.A.; Brusse, L.A.; Low, W.

    1977-10-01

    The series switch is designed to operate at 120kV and pass 65A for 0.5 sec every 30 sec on the Lawrence Berkeley Laboratory CTR Neutral Beam Source Test Stand IIIB. The series switch consists of 400 individual SCR circuits connected in series and is turned on by a simple system of cascaded pulse transformers with multiple single turn secondaries each driving the individual SCR gates. It is turned off by an SCR impulse crowbar that momentarily shorts the power supply allowing the series switch to recover. The SCR switch has been tested in the impulse crowbar configuration and will reliably commutate up to 90A at 120kV. The series switch and impulse crowbar are now in service in Test Stand IIIB. A series switch and impulse crowbar similar in concept is routinely powering a 10 x 10 cm source at 150kV, 20A, 0.5 sec with a 1% duty cycle on the Lawrence Berkeley Laboratory CTR NSB Test Stand IIIA

  11. Analysis of axial behavior of three piece oil control ring; Kumiawase oil ring no jikuhoko kyodo no kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Tateishi, Y.; Fujimura, K.; Hitosugi, H. [Nippon Piston Ring Co. Ltd., Tokyo (Japan)

    1997-10-01

    It is considered that the reduction of oil control ring tension is a major problem in reducing the friction-loss of internal combustion engines. The authors have successfully developed a calculating method for the axial behavior prediction of a three piece type oil control ring as a method used in reduction of lube-oil consumption when lower tension ring is used. By means of the method, the authors found that the effect in reduction of lube-oil consumption was able to be expected by optimizing design parameters of the oil ring, the tension and the seating tab angle of expander-spacer, and the gas pressure on the 3rd land. 3 refs., 14 figs.

  12. Superstrings with zero tension

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J.; Ruiz-Altaba, M. (European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.)

    1989-09-14

    The superstring in the limit of vanishing tension is analyzed with the help of a phase space lagrangian. We show that our formulation is the supersymmetric extension of Schild's null string and that all the symmetries of the standard Green-Schwarz theory are maintained. The null superstring thus arises as a new theoretical laboratory, its complexity between the usual superstring and the massless superparticle. Its canonical quantization is carried through in detail. (orig.).

  13. MANAGEMENT OF STAKEHOLDERS IN HIGH COMPLEXITY PROJECTS: APPLICATIONS AND EMPIRIC EVIDENCES IN CTR NOVA IGUAÇU

    Directory of Open Access Journals (Sweden)

    Fernando Oliveira de Araujo

    2015-12-01

    Full Text Available This article presents the case of implementation of the licensed landfill CTR Nova Iguaçu (the first initiative all around the world certified by the Clean Development Mechanism – CDM, from Kyoto Treaty, providing an analysis of the practices of management of stakeholders adopted with the neighboring communities surrounding the enterprise. Besides the local investigation at the enterprise concerned, the study is supported by technical-scientific literature, highlighting the themes of stakeholders management, change management, and processes of project management, based on the PMI’s 5th Ed PMBoK view. As conclusions, it is seen, in the situation displayed, that actions of identification, planning and monitoring of the stakeholders were crucial to the initiative success, under the economical perspective and concerning corporative image.

  14. Tension-type headache

    DEFF Research Database (Denmark)

    Bendtsen, Lars; Jensen, Rigmor; Bendtsen, Lars

    2009-01-01

    The substantial societal and individual burdens associated with tension-type headache (TTH) constitute a previously overlooked major public health issue. TTH is prevalent, affecting up to 78% of the general population, and 3% suffer from chronic TTH. Pericranial myofascial nociception probably...... is important for the pathophysiology of episodic TTH, whereas sensitization of central nociceptive pathways seems responsible for the conversion of episodic to chronic TTH. Headache-related disability usually can be reduced by identification of trigger factors combined with nonpharmacologic and pharmacologic...

  15. The CTR/COPT-dependent copper uptake and SPL7-dependent copper deficiency responses are required for basal cadmium tolerance in A. thaliana

    Science.gov (United States)

    Copper (Cu) homeostasis in plants is maintained by at least two mechanisms: 1) the miRNA-dependent reallocation of intracellular Cu among major Cu-enzymes and important energy-related functions; 2) the regulation of the expression of Cu transporters including members of the CTR/COPT family. These ev...

  16. Ringing phenomenon of the fiber ring resonator.

    Science.gov (United States)

    Ying, Diqing; Ma, Huilian; Jin, Zhonghe

    2007-08-01

    A resonator fiber-optic gyro (R-FOG) is a high-accuracy inertial rotation sensor based on the Sagnac effect. A fiber ring resonator is the core sensing element in the R-FOG. When the frequency of the fiber ring resonator input laser is swept linearly with time, ringing of the output resonance curve is observed. The output field of the fiber ring resonator is derived from the superposition of the light transmitted through the directional coupler directly and the multiple light components circulated in the fiber ring resonator when the frequency of the laser is swept. The amplitude and phase of the output field are analyzed, and it is found that the difference in time for different light components in the fiber ring resonator to reach a point of destructive interference causes the ringing phenomenon. Finally the ringing phenomenon is observed in experiments, and the experimental results agree with the theoretical analysis well.

  17. General definition of gravitational tension

    International Nuclear Information System (INIS)

    Harmark, T.; Obers, N.A.

    2004-01-01

    In this note we give a general definition of the gravitational tension in a given asymptotically translationally-invariant spatial direction of a space-time. The tension is defined via the extrinsic curvature in analogy with the Hawking-Horowitz definition of energy. We show the consistency with the ADM tension formulas for asymptotically-flat space-times, in particular for Kaluza-Klein black hole solutions. Moreover, we apply the general tension formula to near-extremal branes, constituting a check for non-asymptotically flat space-times. (author)

  18. Minimally invasive tension band wiring technique for olecranon fractures.

    Science.gov (United States)

    Takada, Naoya; Kato, Kenji; Fukuta, Makoto; Wada, Ikuo; Otsuka, Takanobu

    2013-12-01

    Some types of implants, such as plates, screws, wires, and nails, have been used for open reduction and internal fixation of olecranon fractures. A ≥ 10 cm longitudinal incision is used for open reduction and internal fixation of olecranon fractures. According to previous studies, tension band wiring is a popular method that gives good results. However, back out of the wires after the surgery is one of the main postoperative complications. Moreover, if the Kirschner wires are inserted through the anterior ulnar cortex, they may impinge on the radial neck, supinator muscle, or biceps tendon. Herein, we describe the minimally invasive tension band wiring technique using Ring-Pin. This technique can be performed through a 2 cm incision. Small skin incisions are advantageous from an esthetic viewpoint. Ring-Pin was fixed by using a dedicated cable wire that does not back out unless the cable wire breaks or slips out of the dedicated metallic clamp. As the pins are placed in intramedullary canal, this technique does not lead to postoperative complications that may occur after transcortical fixation by conventional tension band wiring. Minimally invasive tension band wiring is one of the useful options for the treatment of olecranon fractures with some advantages.

  19. 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

  20. Radical theory of rings

    CERN Document Server

    Gardner, JW

    2003-01-01

    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  1. Contribution of pelvic floor muscles to stiffness of the pelvic ring

    NARCIS (Netherlands)

    Pool-Goudzwaard, A.L.; Hoek van Dijke, G; van Gurp, M; Mulder, P; Snijders, C.J.; Stoeckart, R.

    2004-01-01

    STUDY DESIGN: A biomechanical study in embalmed specimens, on the relation between applied tension in the pelvic floor muscles, stiffness of the pelvic ring and generation of movement in the sacroiliac joints. OBJECTIVE: To gain insight into the effect of tension in the pelvic floor muscles on

  2. 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.

  3. MUSCLE TENSION DYSPHONIA

    Directory of Open Access Journals (Sweden)

    Irena Hočevar Boltežar

    2004-07-01

    Full Text Available Background. Muscle tension dysphonia (MTD is the cause of hoarseness in almost one half of the patients with voice disorders. The otorhinolaryngologic examination discovers no evident organic lesions in the larynx at least in the beginning of the voice problems. The reason for the hoarse voice is a disordered and maladjusted activity of the muscles taking part in phonation and/or articulation. In some patients, the irregular function of the larynx results in mucosal lesions on vocal folds. The factors participating in the development of MTD, directly or indirectly influence the quality of laryngeal mucosa, the activity of the phonatory muscles and/or increase of the vocal load. In the diagnostics and treatment of the MTD a phoniatrician, a speech and language therapist and a psychologist closely cooperate with the patient who must take an active role. The treatment is a long-lasting one but resulted in a high percentage of clinical success.Conclusions. Most likely, MTD is not a special disease but only a reflection of any disorder in the complicated system of regulation and realization of phonation. The prognosis of treatment is good when all unfavourable factors participating in development of MTD are eliminated and a proper professional voice- and psychotherapy started.

  4. 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

  5. Numerical Simulation of Piston Ring Lubrication

    DEFF Research Database (Denmark)

    Felter, Christian Lotz

    2006-01-01

    and the angle between the normals of the solid and the free surface. The numerical model is compared with the results from an analytical solution of Reynolds equation for a fixed incline slider bearing. Then results from a more compli- cated simulation of piston ring lubrication is given and discussed.......This paper describes a numerical method that can be used to model the lubrication of piston rings. Classical lubrication theory is based on the Reynolds equation which is ap- plicable to confined geometries and open geometries where the flooding conditions are known. Lubrication of piston rings...... on solids and the equilibrium of stresses on the free surface. It is assumed that the surrounding gas phase has zero viscosity. Surface tension can be included in the model if necessary. The contact point where the three phases solid, liquid, and gas intersect is updated based on the velocity of the solid...

  6. Use of sodC versus ctrA for real-time polymerase chain reaction-based detection of Neisseria meningitidis in sterile body fluids

    Directory of Open Access Journals (Sweden)

    Fábio Takenori Higa

    2013-04-01

    Full Text Available We evaluated the use of a newly described sodC-based real-time-polymerase chain reaction (RT-PCR assay for detecting Neisseria meningitidis in normally sterile sites, such as cerebrospinal fluid and serum. The sodC-based RT-PCR assay has an advantage over ctrA for detecting nongroupable N. meningitidis isolates, which are commonly present in asymptomatic pharyngeal carriage. However, in our study, sodC-based RT-PCR was 7.5% less sensitive than ctrA. Given the public health impact of possible false-negative results due to the use of the sodC target gene alone, sodC-based RT-PCR for the diagnosis of meningococcal meningitis should be used with caution.

  7. Note: A thermally stable tension meter for atmospheric soundings using kites.

    Science.gov (United States)

    Walesby, K T; Harrison, R G

    2010-07-01

    Kites offer considerable potential as wind speed sensors--a role distinct from their traditional use as instrument-carrying platforms. In the sensor role, wind speed is measured by kite-line tension. A kite tether line tension meter is described here, using strain gauges mounted on an aluminum ring in a Wheatstone bridge electronic circuit. It exhibits a linear response to tension (19.5 mV N(-1)) with good thermal stability (mean drift of -0.18 N degrees C(-1) over 5-45 degrees C temperature range) and a rapid time response (0.2 s or better). Field comparisons of tether line tension for a Rokkaku kite with a fixed tower sonic anemometer show an approximately linear tension-wind speed relationship over the range 1-6 ms(-1).

  8. Real Closed Rings and Real Closed * Rings

    OpenAIRE

    Capco, Jose

    2007-01-01

    Here we try to distinguish and compare different notions of real closedness mainly one developed by N. Schwartz in his Habilitationschrift and the other developed by A. Sankaranand K. Varadarajan which we shall call real closed *. We stick to the definition of real closed rings as defined and characterized N. Schwartz and we try to determine and characterize real closed rings that are real closed *. The main result is that real closed rings have unique real closure * and that real closure of ...

  9. Evaluation of the reliability of Si3N4-Al2O3 -CTR2O3 ceramics through Weibull analysis

    Directory of Open Access Journals (Sweden)

    Santos Claudinei dos

    2003-01-01

    Full Text Available The objective of this work has been to compare the reliability of two Si3N4 ceramics, with Y2O3/Al2O3 or CTR2O3/Al2O3 mixtures as additives, in regard to their 4-point bending strength and to confirm the potential of the rare earth oxide mixture, CTR2O3, produced at FAENQUIL, as an alternative, low cost sinter additive for pure Y2O3 in the sintering of Si3N4 ceramics. The oxide mixture CTR2O3 is a solid solution formed mainly by Y2O3, Er2O3, Yb2O3 and Dy2O3 with other minor constituents and is obtained at a cost of only 20% of pure Y2O3. Samples were sintered by a gas pressure sintering process at 1900 °C under a nitrogen pressure of 1.5 MPa and an isothermal holding time of 2 h. The obtained materials were characterized by their relative density, phase composition and bending strength. The Weibull analysis was used to describe the reliability of these materials. Both materials produced presented relative densities higher than 99.5%t.d., b-Si3N4 and Y3Al5O12 (YAG as cristalline phases and bending strengths higher than 650 MPa, thus demonstrating similar behaviors regarding their physical, chemical and mechanical characteristics. The statistical analysis of their strength also showed similar results for both materials, with Weibull moduli m of about 15 and characteristic stress values s o of about 700 MPa. These results confirmed the possibility of using the rare earth oxide mixture, CTR2O3, as sinter additive for high performance Si3N4 ceramics, without prejudice of the mechanical properties when compared to Si3N4 ceramics sintered with pure Y2O3.

  10. The Mitochondrial Metallochaperone SCO1 Is Required to Sustain Expression of the High-Affinity Copper Transporter CTR1 and Preserve Copper Homeostasis

    Directory of Open Access Journals (Sweden)

    Christopher J. Hlynialuk

    2015-02-01

    Full Text Available Human SCO1 fulfills essential roles in cytochrome c oxidase (COX assembly and the regulation of copper (Cu homeostasis, yet it remains unclear why pathogenic mutations in this gene cause such clinically heterogeneous forms of disease. Here, we establish a Sco1 mouse model of human disease and show that ablation of Sco1 expression in the liver is lethal owing to severe COX and Cu deficiencies. We further demonstrate that the Cu deficiency is explained by a functional connection between SCO1 and CTR1, the high-affinity transporter that imports Cu into the cell. CTR1 is rapidly degraded in the absence of SCO1 protein, and we show that its levels are restored in Sco1−/− mouse embryonic fibroblasts upon inhibition of the proteasome. These data suggest that mitochondrial signaling through SCO1 provides a post-translational mechanism to regulate CTR1-dependent Cu import into the cell, and they further underpin the importance of mitochondria in cellular Cu homeostasis.

  11. Ejendomsret ctr. forsyningssikkerhed

    DEFF Research Database (Denmark)

    Olesen, Karsten Naundrup

    2007-01-01

    Når man vil løse en bestemt opgave, er der aktiver det er nødvendigt at kunne råde over - vil man eksempelvis levere ambulanceberedskab, må mna have adgang til ambulancer. Udlicitering af offentlige opgaver kan føre til tab af rådighed over sådanne nødvendige aktiver, hvilket kan føre til forsyni...

  12. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1990-01-01

    The main focus of the work by the Fusion Plasma Engineering Group at the University during the prior contract year involved a study of fusion ash (helium) effects on burn efficiency and on potential ways to control ash buildup. This work has wide application to a variety of fusion reactor concepts, but the immediate application for the present work is in the ARIES tokamak reactor design study now being undertaken by a national design team headed by the UCLA. The examples presented here largely deal with the ARIES-I design which is a D-T device operating in the first instability regime

  13. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1991-01-01

    Ash (e.g. thermalized helium from D-T) buildup in a tokamak can potentially prevent ignition and seriously degrade the fusion energy gain from driven system. This problem is most pronounced as the ratio of particle/energy confinement time increases towards the neoclassical limit. Yet much improved confinement of the fuel ions is desirable for a fusion reactor. The goals of the work described here were two fold: to study the effect of helium buildup on the energy balance for a tokamak, and consider methods of active control that might be employed to alleviate the problem. We examine ash buildup effect for both D-T and D- 3 He systems. Most examples used apply to the ARIES 1 D-T reactor design and to the ARIES 3 D- 3 He design since part of this was in support of these two designs. Then we report on brief studies of two potentially attractive control methods, namely controlled sawtooth and fishbone instabilities. The concept is that sawteeth or fishbones would be used on purpose periodically in order to ''flush'' out excess ash from the fusion core. Both methods are shown to feasible and attractive. More study is needed, however, since the phenomenona in which are physically complex. Still the pay off, namely, reduced ash buildup, is exceedingly important so that such studies desires strong attention

  14. Mitochondrial Respiration and Oxygen Tension.

    Science.gov (United States)

    Shaw, Daniel S; Meitha, Karlia; Considine, Michael J; Foyer, Christine H

    2017-01-01

    Measurements of respiration and oxygen tension in plant organs allow a precise understanding of mitochondrial capacity and function within the context of cellular oxygen metabolism. Here we describe methods that can be routinely used for the isolation of intact mitochondria, and the determination of respiratory electron transport, together with techniques for in vivo determination of oxygen tension and measurement of respiration by both CO 2 production and O 2 consumption that enables calculation of the respiratory quotient [CO 2 ]/[O 2 ].

  15. 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

  16. Birth Control Ring

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's in this article? What Is ... español Anillo vaginal anticonceptivo What Is It? The birth control ring is a soft, flexible, doughnut-shaped ...

  17. Constriction model of actomyosin ring for cytokinesis by fission yeast using a two-state sliding filament mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yong-Woon [Department of Chemistry, Texas A and M University, College Station, Texas 77843-3255 (United States); Mascagni, Michael, E-mail: Mascagni@fsu.edu [Departments of Computer Science, Mathematics and Scientific Computing, and Graduate Program in Molecular Biophysics, Florida State University, Tallahassee, Florida 32306-4530 (United States)

    2014-09-28

    We developed a model describing the structure and contractile mechanism of the actomyosin ring in fission yeast, Schizosaccharomyces pombe. The proposed ring includes actin, myosin, and α-actinin, and is organized into a structure similar to that of muscle sarcomeres. This structure justifies the use of the sliding-filament mechanism developed by Huxley and Hill, but it is probably less organized relative to that of muscle sarcomeres. Ring contraction tension was generated via the same fundamental mechanism used to generate muscle tension, but some physicochemical parameters were adjusted to be consistent with the proposed ring structure. Simulations allowed an estimate of ring constriction tension that reproduced the observed ring constriction velocity using a physiologically possible, self-consistent set of parameters. Proposed molecular-level properties responsible for the thousand-fold slower constriction velocity of the ring relative to that of muscle sarcomeres include fewer myosin molecules involved, a less organized contractile configuration, a low α-actinin concentration, and a high resistance membrane tension. Ring constriction velocity is demonstrated as an exponential function of time despite a near linear appearance. We proposed a hypothesis to explain why excess myosin heads inhibit constriction velocity rather than enhance it. The model revealed how myosin concentration and elastic resistance tension are balanced during cytokinesis in S. pombe.

  18. Analyses of layer-thickness effects in bilayered dental ceramics subjected to thermal stresses and ring-on-ring tests

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Chun-Hway [ORNL; Thompson, G. A. [U.S. Army Dental and Trauma Research Detachment, Greak Lakes; Jadaan, Osama M. [University of Wisconsin, Platteville; Wereszczak, Andrew A [ORNL; Becher, Paul F [ORNL

    2008-01-01

    Objectives. The purpose of this study was to analyze the stress distribution through the thickness of bilayered dental ceramics subjected to both thermal stresses and ring-on-ring tests and to systematically examine how the individual layer thickness influences this stress distribution and the failure origin. Methods. Ring-on-ring tests were performed on In-Ceram Alumina/Vitadur Alpha porcelain bilayered disks with porcelain in the tensile side, and In-Ceram Alumina to porcelain layer thickness ratios of 1:2, 1:1, and 2:1 were used to characterize the failure origins as either surface or interface. Based on the thermomechanical properties and thickness of each layer, the cooling temperature from glass transition temperature, and the ring-on-ring loading configuration, the stress distribution through the thickness of the bilayer was calculated using closed-form solutions. Finite element analyses were also performed to verify the analytical results. Results. The calculated stress distributions showed that the location of maximum tension during testing shifted from the porcelain surface to the In-Ceram Alumina/porcelain interface when the relative layer thickness ratio changed from 1:2 to 1:1 and to 2:1. This trend is in agreement with the experimental observations of the failure origins. Significance. For bilayered dental ceramics subjected to ring-on-ring tests, the location of maximum tension can shift from the surface to the interface depending upon the layer thickness ratio. The closed-form solutions for bilayers subjected to both thermal stresses and ring-on-ring tests are explicitly formulated which allow the biaxial strength of the bilayer to be evaluated.

  19. Physics of quantum rings

    CERN Document Server

    Fomin, Vladimir M

    2013-01-01

    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 po

  20. Abolishing the maximum tension principle

    Directory of Open Access Journals (Sweden)

    Mariusz P. Da̧browski

    2015-09-01

    Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.

  1. Portfolios: Assumptions, Tensions, and Possibilities.

    Science.gov (United States)

    Tierney, Robert J.; Clark, Caroline; Fenner, Linda; Herter, Roberta J.; Simpson, Carolyn Staunton; Wiser, Bert

    1998-01-01

    Presents a discussion between two educators of the history, assumptions, tensions, and possibilities surrounding the use of portfolios in multiple classroom contexts. Includes illustrative commentaries that offer alternative perspectives from a range of other educators with differing backgrounds and interests in portfolios. (RS)

  2. CALCULATION OF TENSION FORCE OF BELT CONVEYOR

    OpenAIRE

    Ismet Ibishi; Ahmet Latifi; Gzim Ibishi; Kadri Sejdiu; Melihate Shala-Galica; Bekim Latifi

    2012-01-01

    In this paper is done the explanation on tension fashion of the belt conveyor which is employed in Kosovo Energy Corporation – KEK, for coal transportation to provide electric power plant. The aim of the paper enables to recognize tension forces not to pass with deformation of belt so that this problem will damage the workingprocess. Work principle is based on initial tension and tension during working process. The fact is known that the tension starts from the carriage on the way to tension ...

  3. Brane world black rings

    International Nuclear Information System (INIS)

    Sahay, Anurag; Sengupta, Gautam

    2007-01-01

    Five dimensional neutral rotating black rings are described from a Randall-Sundrum brane world perspective in the bulk black string framework. To this end we consider a rotating black string extension of a five dimensional black ring into the bulk of a six dimensional Randall-Sundrum brane world with a single four brane. The bulk solution intercepts the four brane in a five dimensional black ring with the usual curvature singularity on the brane. The bulk geodesics restricted to the plane of rotation of the black ring are constructed and their projections on the four brane match with the usual black ring geodesics restricted to the same plane. The asymptotic nature of the bulk geodesics are elucidated with reference to a bulk singularity at the AdS horizon. We further discuss the description of a brane world black ring as a limit of a boosted bulk black 2 brane with periodic identification

  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. Spannungsgesteuerter Ring-Oszillator

    OpenAIRE

    Wang, Z.; Thiede, A.

    1999-01-01

    The oscillator (1) of integrated monolithic design has several analogue amplifier units (2) connected in a ring. The individual amplifiers are frequency selective in regard to a resonance frequency. The phase displacements of the amplifiers are chosen so that the total phase displacement over the ring at the resonance frequencies of the amplifiers amounts to 3600 or a whole number multiple of that. The number of amplifiers selected corresponds to the overall quality factor for the ring oscill...

  7. Radioactive gold ring dermatitis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.A.; Aldrich, J.E. (Dalhousie Univ., Halifax, Nova Scotia (Canada))

    1990-08-01

    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.

  8. 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...... is dedicated to vortex rings. Source rings are only briefly mentioned....

  9. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  10. The ring laser gyro

    Science.gov (United States)

    Chow, W. W.; Gea-Banacloche, J.; Pedrotti, L. M.; Sanders, V. E.; Schleich, W.; Scully, M. O.

    1985-01-01

    This paper presents a review of both active and passive ring laser devices. The operating principles of the ring laser are developed and discussed, with special emphasis given to the problems associated with the achievement of greater sensitivity and stability. First-principle treatments of the nature of quantum noise in the ring laser gyro and various methods designed to avoid low-rotation-rate lock-in are presented. Descriptions of state-of-the-art devices and current and proposed applications (including a proposed test of metric theories of gravity using a passive cavity ring laser) are given.

  11. Tensions of Corporate Social Responsibility

    DEFF Research Database (Denmark)

    Strand, Robert

    I engaged with the top management team (TMT) and employees of American Cafes Corporation as an action/intervention researcher in the 20 months immediately following the TMT’s decision to formalize the company’s corporate social responsibility (CSR) activities. This led to the establishment...... CSR agenda is considered, which brings with it a multiplicity of substantively rational ends for which the corporation could pursue. I show the CSR bureaucracy can create a space for reflection in which the multiplicity of substantively rational ends can be considered, negotiated, and selected...... for reflection within the corporation. But I also show tensions can arise from the establishment of the CSR bureaucracy itself. This suggests the CSR bureaucracy itself resides in a tension....

  12. Robust Tensioned Kevlar Suspension Design

    Science.gov (United States)

    Young, Joseph B.; Naylor, Bret J.; Holmes, Warren A.

    2012-01-01

    One common but challenging problem in cryogenic engineering is to produce a mount that has excellent thermal isolation but is also rigid. Such mounts can be achieved by suspending the load from a network of fibers or strings held in tension. Kevlar fibers are often used for this purpose owing to their high strength and low thermal conductivity. A suite of compact design elements has been developed to improve the reliability of suspension systems made of Kevlar.

  13. 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

  14. Children of Sex Rings.

    Science.gov (United States)

    Hunt, Patricia; Baird, Margaret

    1990-01-01

    Outlines three major differentiating categories of children who were sexually abused by sex rings: level of fear, ability to trust, and disclosure confusion. Addresses denial and resistance regarding child sexual exploitation by a ring among practitioners in the child welfare system. (Author/BB)

  15. Illustration of Saturn's Rings

    Science.gov (United States)

    2001-01-01

    This illustration shows a close-up of Saturn's rings. These rings are thought to have formed from material that was unable to form into a Moon because of tidal forces from Saturn, or from a Moon that was broken up by Saturn's tidal forces.

  16. Relativistic ring models

    Energy Technology Data Exchange (ETDEWEB)

    Ujevic, Maximiliano [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Letelier, Patricio S.; Vogt, Daniel [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Matematica, Estatistica e Computacao Cientifica. Dept. de Matematica Aplicada

    2011-07-01

    Full text: Relativistic thick ring models are constructed using previously found analytical Newtonian potential-density pairs for flat rings and toroidal structures obtained from Kuzmin-Toomre family of discs. This was achieved by inflating previously constructed Newtonian ring potentials using the transformation |z|{yields}{radical}z{sup 2} + b{sup 2}, and then finding their relativistic analog. The models presented have infinite extension but the physical quantities decays very fast with the distance, and in principle, one could make a cut-off radius to consider it finite. In particular, we present systems with one ring, two rings and a disc with a ring. Also, the circular velocity of a test particle and its stability when performing circular orbits are presented in all these models. Using the Rayleigh criterion of stability of a fluid at rest in a gravitational field, we find that the different systems studied present a region of non-stability that appears in the intersection of the disc and the ring, and between the rings when they become thinner. (author)

  17. Imaging rings in ring imaging Cherenkov counters

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliff, Blair N

    2002-11-25

    The general concepts used to form images in Ring Imaging Cherenkov (RICH) counters are described and their performance properties compared. Particular attention is paid to issues associated with imaging in the time dimension, especially in Detectors of Internally Reflected Cherenkov light (DIRCs).

  18. Rings and their modules

    CERN Document Server

    Bland, Paul E

    2011-01-01

    This book is an introduction to the theory of rings and modules that goes beyond what one normally obtains in a graduate course in abstract algebra. In addition to the presentation of standard topics in ring and module theory, it also covers category theory, homological algebra and even more specialized topics like injective envelopes and projective covers, reflexive modules and quasi-Frobenius rings, and graded rings and modules. The book is a self-contained volume written in a very systematic style: allproofs are clear and easy for the reader to understand and allarguments are based onmaterials contained in the book. A problem sets follow each section. It is suitable for graduate and PhD students who have chosen ring theory for their research subject.

  19. DOUBLE-RING AND TENSION INFILTROMETER MEASUREMENTS OF HYDRAULIC CONDUCTIVITY AND MOBILE SOIL REGIONS MEDIDAS DE CONDUTIVIDADE HIDRÁULICA E MOVIMENTO DE ÁGUA NO SOLO POR ANÉIS CONCÊNTRICOS E INFILTRÔMETRO DE TENSÃO

    Directory of Open Access Journals (Sweden)

    Bernd Lennartz

    2011-07-01

    Full Text Available

    There are several field methods and techniques for measuring Ks. In this study, double-ring (DI and tension infiltrometer (TI infiltration techniques were combined with dye tracer application and compared for estimating Ks and the mobile soil fraction on a structured sandy loam soil (Gleyic Luvisol, in Rostock, Germany. Water was infiltrated into soil by using three

  20. Superdualities, brane tensions and massive IIA/IIB duality

    International Nuclear Information System (INIS)

    Lavrinenko, I.V.; Lue, H.; Pope, C.N.; Stelle, K.S.

    1999-01-01

    The gauge transformations of p-form fields in supergravity theories acquire a non-commuting character when one introduces potentials both for the theory's original field strengths and for their duals. This has previously been shown in the 'doubled' formalism for maximal supergravities, where a generalised duality relation between original and dual field strengths replaces the equations of motion. In the doubled formalism, the gauge transformations generate a superalgebra, and the corresponding symmetries have accordingly been called 'superdualities'. The corresponding Noether charges form a representation of the cohomology ring on the space-time manifold. In this paper, we show that the gauge symmetry superalgebra implies certain non-trivial relations among the various p-brane tensions, which can straightforwardly be read off from the superalgebra commutation relations. This provides an elegant derivation of the brane-tension relations purely within a given theory, without the need to make use of duality relations between different theories, such as the type IIA/IIB T-duality, although the results are consistent with such dualities. We present the complete set of brane-tension relations in M-theory, in the type IIA and type IIB theories, and in all the lower-dimensional maximal supergravities. We also construct a doubled formalism for massive type IIA supergravity, and this enables us to obtain the brane-tension relations involving the D8-brane, purely within the framework of the massive IIA theory. We also obtain explicit transformations for the nine-dimensional T-duality between the massive type IIA theory and the Scherk-Schwarz reduced type IIB theory

  1. 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...... with the probe L1.26 confirmed the derivation from chromosome 13 and DNA polymorphism analysis showed maternal origin of the ring chromosome. Our results, together with a review of previous reports of cases with ring chromosome 13 with identified breakpoints, could neither support the theory of distinct clinical...

  2. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

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

  3. Origen de la Cefalea Tensional

    OpenAIRE

    Romero Godoy, Rosalinda; Romero Godoy, Sara Raquel

    2010-01-01

    Introducción y objetivos: La cefalea es una de las causas de consulta médica más comunes y el síntoma más frecuente consultado en neurología. La prevalencia según estudios estadísticos nacionales es de un 62% en hombres y un 86% en mujeres. De todas las cefaleas la cefalea tensional es la más común, pero la menos estudiada y conocida. Nos hemos propuesto hacer una revisión actual sobre la etiopatogenia en las cefaleas tensionales que nos pueda orientar a futuras investigaciones. ...

  4. 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.

  5. Saturn's dynamic D ring

    Science.gov (United States)

    Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.

    2007-01-01

    The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, <40-km wide ringlet to a much broader and more diffuse 250-km wide feature. In addition, its center of light has shifted inwards by over 200 km relative to other features in the D ring. Cassini also finds that the locations of other narrow features in the D ring and the structure of the diffuse material in the D ring differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D ring that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C ring that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D ring contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D ring that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D ring produced by differential nodal regression of an initially inclined ring. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.

  6. Child sex rings.

    OpenAIRE

    Wild, N J; Wynne, J M

    1986-01-01

    Details of 11 child sex rings identified in one working class community were obtained by interviewing investigating police officers and examining health and social services records. The rings contained 14 adult male perpetrators and 175 children aged 6-15 years. Most perpetrators used child ringleaders to recruit victims; others became a "family friend" or obtained a position of authority over children. Secrecy was encouraged and bribery, threats, and peer pressure used to induce participatio...

  7. 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

  8. Matrimonial ring structures

    OpenAIRE

    Hamberger, Klaus; Houseman, Michael; Daillant, Isabelle; White, Douglas R.; Barry, Laurent

    2006-01-01

    The paper deals with matrimonial rings, a particular kind of cycles in kinship networks which result when spouses are linked to each other by ties of consanguinity or affinity. By taking a network-analytic perspective, the paper endeavours to put this classical issue of structural kinship theory on a general basis, such as to allow conclusions which go beyond isolated discussions of particular ring types (like "cross-cousin marriage", "sister exchange", and so forth). The paper provides a def...

  9. Update on normal tension glaucoma

    Directory of Open Access Journals (Sweden)

    Jyotiranjan Mallick

    2016-01-01

    Full Text Available Normal tension glaucoma (NTG is labelled when typical glaucomatous disc changes, visual field defects and open anterior chamber angles are associated with intraocular pressure (IOP constantly below 21 mmHg. Chronic low vascular perfusion, Raynaud's phenomenon, migraine, nocturnal systemic hypotension and over-treated systemic hypertension are the main causes of normal tension glaucoma. Goldmann applanation tonometry, gonioscopy, slit lamp biomicroscopy, optical coherence tomography and visual field analysis are the main tools of investigation for the diagnosis of NTG. Management follows the same principles of treatment for other chronic glaucomas: To reduce IOP by a substantial amount, sufficient to prevent disabling visual loss. Treatment is generally aimed to lower IOP by 30% from pre-existing levels to 12-14 mmHg. Betaxolol, brimonidine, prostaglandin analogues, trabeculectomy (in refractory cases, systemic calcium channel blockers (such as nifedipine and 24-hour monitoring of blood pressure are considered in the management of NTG. The present review summarises risk factors, causes, pathogenesis, diagnosis and management of NTG.

  10. The study and design of tension controller

    Science.gov (United States)

    Jun, G.; Lamei, X.

    2018-02-01

    Tension control is a wide used technology in areas such as textiles, paper and plastic films. In this article, the tension control system release and winding process is analyzed and the mathematical model of tension control system is established, and a high performance tension controller is designed. In hardware design, STM32F130 single chip microcomputer is used as the control core, which has the characteristics of fast running speed and rich peripheral features. In software design, μC/OS-II operating system is introduced to improve the efficiency of single chip microcomputer, and enhance the independence of each module, and make development and maintenance more convenient. The taper tension control is adopted in the winding part, which can effectively solve the problem of rolling shrinkage. The results show that the tension controller has the characteristics of simple structure, easy operation and stable performance.

  11. Ezrin enhances line tension along transcellular tunnel edges via NMIIa driven actomyosin cable formation

    Science.gov (United States)

    Stefani, Caroline; Gonzalez-Rodriguez, David; Senju, Yosuke; Doye, Anne; Efimova, Nadia; Janel, Sébastien; Lipuma, Justine; Tsai, Meng Chen; Hamaoui, Daniel; Maddugoda, Madhavi P.; Cochet-Escartin, Olivier; Prévost, Coline; Lafont, Frank; Svitkina, Tatyana; Lappalainen, Pekka; Bassereau, Patricia; Lemichez, Emmanuel

    2017-06-01

    Transendothelial cell macroaperture (TEM) tunnels control endothelium barrier function and are triggered by several toxins from pathogenic bacteria that provoke vascular leakage. Cellular dewetting theory predicted that a line tension of uncharacterized origin works at TEM boundaries to limit their widening. Here, by conducting high-resolution microscopy approaches we unveil the presence of an actomyosin cable encircling TEMs. We develop a theoretical cellular dewetting framework to interpret TEM physical parameters that are quantitatively determined by laser ablation experiments. This establishes the critical role of ezrin and non-muscle myosin II (NMII) in the progressive implementation of line tension. Mechanistically, fluorescence-recovery-after-photobleaching experiments point for the upstream role of ezrin in stabilizing actin filaments at the edges of TEMs, thereby favouring their crosslinking by NMIIa. Collectively, our findings ascribe to ezrin and NMIIa a critical function of enhancing line tension at the cell boundary surrounding the TEMs by promoting the formation of an actomyosin ring.

  12. Robust gap repair in the contractile ring ensures timely completion of cytokinesis.

    Science.gov (United States)

    Silva, Ana M; Osório, Daniel S; Pereira, Antonio J; Maiato, Helder; Pinto, Inês Mendes; Rubinstein, Boris; Gassmann, Reto; Telley, Ivo Andreas; Carvalho, Ana Xavier

    2016-12-19

    Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore the biophysical properties of constricting rings in Caenorhabditis elegans embryos. Laser cutting causes rings to snap open. However, instead of disintegrating, ring topology recovers and constriction proceeds. In response to severing, a finite gap forms and is repaired by recruitment of new material in an actin polymerization-dependent manner. An open ring is able to constrict, and rings repair from successive cuts. After gap repair, an increase in constriction velocity allows cytokinesis to complete at the same time as controls. Our analysis demonstrates that tension in the ring increases while net cortical tension at the site of ingression decreases throughout constriction and suggests that cytokinesis is accomplished by contractile modules that assemble and contract autonomously, enabling local repair of the actomyosin network. Consequently, cytokinesis is a highly robust process impervious to discontinuities in contractile ring structure. © 2016 Silva et al.

  13. The Plastic Tension Field Method

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    . The emphasis is attached to the presentation of a design method based on the diagonal tension field theory. Also, how to determine the load-carrying capacity of a given steel plate girder with transverse web stiffeners, is briefly presented. The load-carrying capacity may be predicted by applying both...... method. The method is based on the theory of plasticity and is analogous to the so-called diagonal compression field method developed for reinforced concrete beams with transverse stirrups, which is adopted in the common European concrete code (Eurocode 2). Many other theories have been developed......, but the method presented differs from these theories by incorporating the strength of the transverse stiffeners and by the assumption that the tensile bands may pass the transverse stiffeners, which often is observed in tests. Other methods have only dealt with a single web field between two stiffeners...

  14. 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)

  15. 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.

  16. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  17. Embracing Tensions in Feminist Organizational Communication Pedagogies

    Science.gov (United States)

    Linabary, Jasmine R.; Long, Ziyu; Mouton, Ashton; Rao, Ranjani L.; Buzzanell, Patrice M.

    2017-01-01

    Feminist pedagogies hold potential to create more inclusive and transformative classrooms. Adopting a tension-centered approach, we draw on our individual and collective reflections on the design and instruction of a multi-section undergraduate organizational communication course to build an autoethnographic account of the tensions associated with…

  18. Surface tension measurements with a smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-11-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept of surface tension through simple experiments.

  19. Intraoperative Development of Tension Pneumocephalus in a ...

    African Journals Online (AJOL)

    Rapid buildup of gas within the cranial vault can result in a life‑threatening condition known as “tension pneumocephalus,” necessitating immediate surgical intervention. Nitrous oxide (N2O), a commonly used inhaled anesthetic, is associated with the development of tension pneumocephalus and its role in neurosurgical ...

  20. Tension Pneumothorax following an Accidental Kerosene Poisoning ...

    African Journals Online (AJOL)

    Tension pneumothorax is a rare complication following an accidental kerosene poisoning. In such situation, a bed-side needle thoracocentesis is performed because of its potential of becoming fatal; hence its clinical importance. A case of 15 month old boy with tension pneumothorax following accidental kerosene ...

  1. Traumatic tension pneumocephalus: Two case reports

    Directory of Open Access Journals (Sweden)

    Abubaker Al-Aieb

    2017-01-01

    Conclusions: These are two rare cases with posttraumatic tension pneumocephalus treated conservatively with a favorable outcome. Early diagnosis of tension pneumocephalus is a crucial step to facilitate early recovery; however, the associated injuries need attention as they could influence the hospital course.

  2. Tension and robustness in multitasking cellular networks.

    Directory of Open Access Journals (Sweden)

    Jeffrey V Wong

    Full Text Available Cellular networks multitask by exhibiting distinct, context-dependent dynamics. However, network states (parameters that generate a particular dynamic are often sub-optimal for others, defining a source of "tension" between them. Though multitasking is pervasive, it is not clear where tension arises, what consequences it has, and how it is resolved. We developed a generic computational framework to examine the source and consequences of tension between pairs of dynamics exhibited by the well-studied RB-E2F switch regulating cell cycle entry. We found that tension arose from task-dependent shifts in parameters associated with network modules. Although parameter sets common to distinct dynamics did exist, tension reduced both their accessibility and resilience to perturbation, indicating a trade-off between "one-size-fits-all" solutions and robustness. With high tension, robustness can be preserved by dynamic shifting of modules, enabling the network to toggle between tasks, and by increasing network complexity, in this case by gene duplication. We propose that tension is a general constraint on the architecture and operation of multitasking biological networks. To this end, our work provides a framework to quantify the extent of tension between any network dynamics and how it affects network robustness. Such analysis would suggest new ways to interfere with network elements to elucidate the design principles of cellular networks.

  3. Pressure-tension test for assessing fatigue in concrete

    Science.gov (United States)

    Soleimani, Sayed M.; Boyd, Andrew J.; Komar, Andrew J. K.

    2017-04-01

    In a pressure-tension test, a cylindrical concrete specimen is inserted into a cylindrical steel jacket, with a rubber ``O'' ring seal at each end to prevent gas leakage. Gas pressure is then applied to the curved surface of the concrete cylinder, leaving the ends free. As the gas pressure is increased, the specimen eventually fractures across a single plane transverse to the axis of the cylinder. The gas pressure at fracture may then be considered as the tensile strength of the concrete. In this study, the pressure-tension test is used to study fatigue in concrete. A total of 22 standard concrete cylinders (100 mm × 200 mm) were tested. Both dry and wet specimens have been studied. Low-cycle loading, which involves the application of a few load cycles at high stress levels - such as a concrete structure under earthquake load - has been used in this study. It was found that the concrete specimens in a low-cycle loading fail after only a few cycles of loading and interestingly at a stress level lower than the maximum value applied in the cyclic loading. In addition, non-destructive testing (NDT) was performed to determine the progressive damage due to tensile load in concrete cylinders using Ultrasonic Pulse Velocity (UPV). It was found that UPV can be used to evaluate the damage in concrete even after the application of a very low-level of tensile stress - as low as 10% of its tensile strength.

  4. Initial tension loss in cerclage cables.

    Science.gov (United States)

    Ménard, Jérémie; Émard, Maxime; Canet, Fanny; Brailovski, Vladimir; Petit, Yvan; Laflamme, George Y

    2013-10-01

    Cerclage cables, frequently used in the management of fractures and osteotomies, are associated with a high failure rate and significant loosening during surgery. This study compared the capacity to maintain tension of different types of orthopaedic cable systems. Multifilament Cobalt-Chrome (CoCr) cables with four different crimp/clamp devices (DePuy, Stryker, Zimmer and Smith&Nephew) and one non-metallic Nylon (Ny) cable from Kinamed were instrumented with a load cell to measure tension during insertion. Significant tension loss was observed with crimping for all cables (Ptensioner led to an additional unexpected tension loss (CoCr-DePuy: 18%, CoCr-Stryker: 29%, CoCr-Smith&Nephew: 33%, Ny: 46%, and CoCr-Zimmer: 52%). The simple CoCr (DePuy) cable system outperformed the more sophisticated locking devices due to its significantly better ability to prevent tension loss. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Fusion rings and fusion ideals

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    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...... 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...

  6. 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...... functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also compute the fu- sion rings for type G2....

  7. 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.)

  8. 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.

  9. 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

  10. Ring Bubbles of Dolphins

    Science.gov (United States)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  11. Mini-Tn7 Insertion in an Artificial attTn7 Site Enables Depletion of the Essential Master Regulator CtrA in the Phytopathogen Agrobacterium tumefaciens.

    Science.gov (United States)

    Figueroa-Cuilan, Wanda; Daniel, Jeremy J; Howell, Matthew; Sulaiman, Aliyah; Brown, Pamela J B

    2016-08-15

    Mechanistic studies of many processes in Agrobacterium tumefaciens have been hampered by a lack of genetic tools for characterization of essential genes. In this study, we used a Tn7-based method for inducible control of transcription from an engineered site on the chromosome. We demonstrate that this method enables tighter control of inducible promoters than plasmid-based systems and can be used for depletion studies. The method enables the construction of depletion strains to characterize the roles of essential genes in A. tumefaciens Here, we used the strategy to deplete the alphaproteobacterial master regulator CtrA and found that depletion of this essential gene results in dramatic rounding of cells, which become nonviable. Agrobacterium tumefaciens is a bacterial plant pathogen and natural genetic engineer. Thus, studies of essential processes, including cell cycle progression, DNA replication and segregation, cell growth, and division, may provide insights for limiting disease or improving biotechnology applications. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  12. Dynamical modeling of surface tension

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Kothe, D.B.

    1996-01-01

    In a recent review it is said that free-surface flows ''represent some of the difficult remaining challenges in computational fluid dynamics''. There has been progress with the development of new approaches to treating interfaces, such as the level-set method and the improvement of older methods such as the VOF method. A common theme of many of the new developments has been the regularization of discontinuities at the interface. One example of this approach is the continuum surface force (CSF) formulation for surface tension, which replaces the surface stress given by Laplace's equation by an equivalent volume force. Here, we describe how CSF might be made more useful. Specifically, we consider a derivation of the CSF equations from a minimization of surface energy as outlined by Jacqmin. This reformulation suggests that if one eliminates the computation of curvature in terms of a unit normal vector, parasitic currents may be eliminated For this reformulation to work, it is necessary that transition region thickness be controlled. Various means for this, in addition to the one discussed by Jacqmin are discussed

  13. On the measurement of surface tension in binders used for moulding sands

    Directory of Open Access Journals (Sweden)

    B. Hutera

    2008-07-01

    Full Text Available The surface tension of foundry binders is a very important parameter affecting the properties of a sand-binder system. Combined with other parameters, its value determines an outcome of the process of moulding sand preparation and the mechanical properties of the ready moulding composition. The problem of how to measure the surface tension of binders used in preparation of moulding sands is discussed only occasionally. Indirectly, the surface tension is characterised by the value of a contact angle, but it never means that these two parameters can be considered identical. Numerous methods are available and used at present to measure the surface tension, among others, the capillary rise method, the spinning drop method, the sessile drop method, the pendant drop method, the method of pulled out ring (or plate, or frame. There is also a rich variety of devices offered with different measuring methods. The devices are modern and represent a high level of the technical skill and art. Unfortunately, also their price is high. It is, however, possible to obtain the reliable results of the surface tension measurement using relatively simple methods, viz. the stalagmometric method and the capillary rise method. What is necessary are proper conditions of the measurement, directly related with the specific properties of binders. The present paper gives examples of the results obtained during measurement of the surface tension of some selected binders. Attention was drawn to the methods of taking measurements, and the obtained results were discussed and analysed. The possibilities of detemining the surface tension of the examined binders from the results of the contact angle measurements using the “sessile drop” and “pendant drop” methods were outlined.

  14. Prestressed Ring Beam in the Church of St. Peter’s and Paul’s in Bodzanow, Design and Realization

    Science.gov (United States)

    Szydlowski, Rafal; Labuzek, Barbara; Turcza, Monika

    2017-10-01

    The present trend in architecture is designing thin. slender and spacious architectural forms. It has become the reason for searching for new solutions and finding new ways of use of the existing construction ones. Recently, the first time in Poland, the post-tensioning has been used in realization of church building. In the Church of St. Peter’s and Paul’s in Bodzanow (near Cracow) was designed circumferential ring beam post-tensioned with 4 unbounded tendons to transfer peripheral tensile forces from the roof. Thanks to the use of a prestressed ring beam hidden in the wall, large cross-section of roof girders was possible to be avoided, as well as a massive reinforced concrete ring or additional steel tie-rods. The paper presents the applied solutions in details with the theoretical calculated results as well as the results of prestressing measured in site during tensioning of tendons. Based on presented results some conclusions have been drawn.

  15. 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

  16. 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.

  17. e-læring

    DEFF Research Database (Denmark)

    Helms, Niels Henrik

    e-læring kan defineres på ganske mange måder. Ordet e-læring består jo tydeligt nok af to elementer. E + læring ligesom e-handel eller e-banking, og umiddelbart vil de fleste nok sige, at det så handler om læring vha. internettet. I bidraget advokeres for en læringsmæssig frem for normativ tilgang....

  18. 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...

  19. Clean elements in abelian rings

    Indian Academy of Sciences (India)

    equivalent to being clean for an abelian ring is 'topologically boolean'. In line with [1] we say that a ring R (not necessarily commutative) is right (resp. left) topologically boolean, or a right (resp. left) tb-ring for short, if for every pair of distinct maximal right (resp. left) ideals of R there is an idempotent in exactly one of them.

  20. 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.

  1. Tension waves in tethered satellite cables

    Science.gov (United States)

    Lallman, F. J.

    1984-01-01

    A one-degree-of-freedom simulation of the Tethered Satellite System (TSS) was programmed using a distributed system model of the tether based on the one-dimensional wave equation. This model represents the time varying tension profile along the tether as the sum of two traveling waves of tension moving in opposite directions. A control loop was devised which combines a deployment rate command with the measured tension at the deployer to produce a smooth, stable rate of deployment of the subsatellite. Simulation results show a buildup of periodic bursts of high frequency oscillation in tension. This report covers the mathematical modelling and simulation results and explains the reason for the observed oscillations. The design of a possible vibration damping device is discussed.

  2. Foundation design for high tension cable guardrails.

    Science.gov (United States)

    2010-06-01

    High tension cable guardrail is becoming increasing popular in median and roadside applications due to the promise of reduced deflections upon impact and reduced maintenance. As the performance of these systems is observed in service, there is a grow...

  3. Modelling Tension Stiffening in Reinforced Concrete Structures

    DEFF Research Database (Denmark)

    Christiansen, Morten Bo; Nielsen, Mogens Peter

    1997-01-01

    Part I of the present thesis deals with crack formation in reinforced concrete and the phenomenon of tension stiffening in concrete tension rods reinforced with deformed bars.Two physical models are presented for uniaxial tension, and they are modified for application on beams subjected to pure...... predicted by the models are compared with experimental data from tests on tension rods as well as flexural beams.In the light of the simple assumptions made and the random nature of cracking, the accordance between the models and the test data is quite good.Part II of the present thesis deals...... flexure.In the first model, the yield zone model, it is assumed that the mean crack distance is a descending function of the reinforcement stress in a crack. Furthermore it is assumed that in certain zones between the cracks the concrete is carrying its full effective tensile strength, i.e. the concrete...

  4. Tension Hydrothorax Related to Disseminated Endometriosis

    Directory of Open Access Journals (Sweden)

    AnnaKate Deal, MD

    2016-01-01

    Full Text Available We present the case of a 34-year-old woman presenting to the emergency department (ED with dyspnea, cough, and fever. She was found to have a tension hydrothorax and was treated with ultrasound-guided thoracentesis in the ED. Subsequent inpatient evaluation showed the patient had disseminated endometriosis. Tension hydrothorax has not been previously described in the literature as a complication of this disease.

  5. Ehrlichia chaffeensis proliferation begins with NtrY/NtrX and PutA/GlnA upregulation and CtrA degradation induced by proline and glutamine uptake.

    Science.gov (United States)

    Cheng, Zhihui; Lin, Mingqun; Rikihisa, Yasuko

    2014-11-25

    How the obligatory intracellular bacterium Ehrlichia chaffeensis begins to replicate upon entry into human monocytes is poorly understood. Here, we examined the potential role of amino acids in initiating intracellular replication. PutA converts proline to glutamate, and GlnA converts glutamate to glutamine. E. chaffeensis PutA and GlnA complemented Escherichia coli putA and glnA mutants. Methionine sulfoximine, a glutamine synthetase inhibitor, inhibited E. chaffeensis GlnA activity and E. chaffeensis infection of human cells. Incubation of E. chaffeensis with human cells rapidly induced putA and glnA expression that peaked at 24 h postincubation. E. chaffeensis took up proline and glutamine but not glutamate. Pretreatment of E. chaffeensis with a proline transporter inhibitor (protamine), a glutamine transporter inhibitor (histidine), or proline analogs inhibited E. chaffeensis infection, whereas pretreatment with proline or glutamine enhanced infection and upregulated putA and glnA faster than no treatment or glutamate pretreatment. The temporal response of putA and glnA expression was similar to that of NtrY and NtrX, a two-component system, and electrophoretic mobility shift assays showed specific binding of recombinant E. chaffeensis NtrX (rNtrX) to the promoter regions of E. chaffeensis putA and glnA. Furthermore, rNtrX transactivated E. chaffeensis putA and glnA promoter-lacZ fusions in E. coli. Growth-promoting activities of proline and glutamine were also accompanied by rapid degradation of the DNA-binding protein CtrA. Our results suggest that proline and glutamine uptake regulates putA and glnA expression through NtrY/NtrX and facilitates degradation of CtrA to initiate a new cycle of E. chaffeensis growth. Human monocytic ehrlichiosis (HME) is one of the most prevalent, life-threatening emerging infectious zoonoses in the United States. HME is caused by infection with E. chaffeensis, an obligatory intracellular bacterium in the order

  6. Density and surface tension of ionic liquids.

    Science.gov (United States)

    Kolbeck, C; Lehmann, J; Lovelock, K R J; Cremer, T; Paape, N; Wasserscheid, P; Fröba, A P; Maier, F; Steinrück, H-P

    2010-12-30

    We measured the density and surface tension of 9 bis[(trifluoromethyl)sulfonyl]imide ([Tf(2)N](-))-based and 12 1-methyl-3-octylimidazolium ([C(8)C(1)Im](+))-based ionic liquids (ILs) with the vibrating tube and the pendant drop method, respectively. This comprehensive set of ILs was chosen to probe the influence of the cations and anions on density and surface tension. When the alkyl chain length in the [C(n)C(1)Im][Tf(2)N] series (n = 1, 2, 4, 6, 8, 10, 12) is increased, a decrease in density is observed. The surface tension initially also decreases but reaches a plateau for alkyl chain lengths greater than n = 8. Functionalizing the alkyl chains with ethylene glycol groups results in a higher density as well as a higher surface tension. For the dependence of density and surface tension on the chemical nature of the anion, relations are only found for subgroups of the studied ILs. Density and surface tension values are discussed with respect to intermolecular interactions and surface composition as determined by angle-resolved X-ray photoelectron spectroscopy (ARXPS). The absence of nonvolatile surface-active contaminants was proven by ARXPS.

  7. Oxygen tension level and human viral infections

    Energy Technology Data Exchange (ETDEWEB)

    Morinet, Frédéric, E-mail: frederic.morinet@sls.aphp.fr [Centre des Innovations Thérapeutiques en Oncologie et Hématologie (CITOH), CHU Saint-Louis, Paris (France); Université Denis Diderot, Sorbonne Paris Cité Paris, Paris (France); Casetti, Luana [Institut Cochin INSERM U1016, Paris (France); François, Jean-Hugues; Capron, Claude [Institut Cochin INSERM U1016, Paris (France); Laboratoire d' Hématologie, Hôpital Ambroise Paré, Boulogne (France); Université de Versailles Saint-Quentin en Yvelynes, Versailles (France); Pillet, Sylvie [Laboratoire de Bactériologie-Virologie-Hygiène, CHU de Saint-Etienne, Saint-Etienne (France); Université de Lyon et Université de Saint-Etienne, Jean Monnet, GIMAP EA3064, F-42023 Saint-Etienne, Lyon (France)

    2013-09-15

    The role of oxygen tension level is a well-known phenomenon that has been studied in oncology and radiotherapy since about 60 years. Oxygen tension may inhibit or stimulate propagation of viruses in vitro as well as in vivo. In turn modulating oxygen metabolism may constitute a novel approach to treat viral infections as an adjuvant therapy. The major transcription factor which regulates oxygen tension level is hypoxia-inducible factor-1 alpha (HIF-1α). Down-regulating the expression of HIF-1α is a possible method in the treatment of chronic viral infection such as human immunodeficiency virus infection, chronic hepatitis B and C viral infections and Kaposi sarcoma in addition to classic chemotherapy. The aim of this review is to supply an updating concerning the influence of oxygen tension level in human viral infections and to evoke possible new therapeutic strategies regarding this environmental condition. - Highlights: • Oxygen tension level regulates viral replication in vitro and possibly in vivo. • Hypoxia-inducible factor 1 (HIF-1α) is the principal factor involved in Oxygen tension level. • HIF-1α upregulates gene expression for example of HIV, JC and Kaposi sarcoma viruses. • In addition to classical chemotherapy inhibition of HIF-1α may constitute a new track to treat human viral infections.

  8. Tensile mechanical behavior of hollow and filled carbon nanotubes under tension or combined tension-torsion

    Science.gov (United States)

    Jeong, Byeong-Woo; Lim, Jang-Keun; Sinnott, Susan B.

    2007-01-01

    The tensile mechanical behavior of hollow and filled single-walled carbon nanotubes under tension or combined tension-torsion is examined using classical molecular dynamics simulations. These simulations indicate that the tensile strength under combined tension-torsion can be increased by filling the carbon nanotubes, and the amount of this increase depends on the kind of filling material. They also predict that the tensile strength under combined tension-torsion decreases linearly under applied torsion. The tensile strength can be modified by adjusting the system temperature and through chemical functionalization to the carbon nanotube walls.

  9. Claisen thermally rearranged (CTR) polymers

    Science.gov (United States)

    Tena, Alberto; Rangou, Sofia; Shishatskiy, Sergey; Filiz, Volkan; Abetz, Volker

    2016-01-01

    Thermally rearranged (TR) polymers, which are considered the next-generation of membrane materials because of their excellent transport properties and high thermal and chemical stability, are proven to have significant drawbacks because of the high temperature required for the rearrangement and low degree of conversion during this process. We demonstrate that using a [3,3]-sigmatropic rearrangement, the temperature required for the rearrangement of a solid glassy polymer was reduced by 200°C. Conversions of functionalized polyimide to polybenzoxazole of more than 97% were achieved. These highly mechanically stable polymers were almost five times more permeable and had more than two times higher degrees of conversion than the reference polymer treated under the same conditions. Properties of these second-generation TR polymers provide the possibility of preparing efficient polymer membranes in a form of, for example, thin-film composite membranes for various gas and liquid membrane separation applications. PMID:27482538

  10. Surface tension of a coal extract in an organic solvent; Sekitan chushutsu seibun no kaigo to hyomen choryoku

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T.; Hayasaka, K.; Takanohashi, T.; Iino, M. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

    1996-10-28

    The behavior and properties of associated bodies were studied through measurement of surface tension considering acetone-soluble fraction relatively light among various solvent extracts of coal. In experiment, the acetone-soluble fraction was extracted from the substances extracted from Upper Freeport coal as standard specimen using the mixed solvent of carbon disulfide (CS2) and N-methyl-2-pyrrolidinone (NMP), and it was dissolved into NMP after drying. Surface tension was measured by Wilhelmy method. The experimental results are as follows. Equilibrium surface tension is equal to the surface tension of pure solvent in a low concentration range of solution, and decreases with an increase in concentration approaching a fixed value at 0 in log concentration, nearly showing an S curve. Adsorption of species with non-polar aromatic ring of the acetone-soluble fraction on a solution surface probably decreases surface tension. Change with time in surface tension is observed which suggests fast initial reaction and slow subsequent reaction. 4 figs.

  11. 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.)

  12. Oxygen tension affects lubricin expression in chondrocytes.

    Science.gov (United States)

    Hatta, Taku; Kishimoto, Koshi N; Okuno, Hiroshi; Itoi, Eiji

    2014-10-01

    We assessed the effects of oxygen tension on lubricin expression in bovine chondrocytes and cartilage explants and a role for hypoxia-inducible transcription factor (HIF)-1α in regulating lubricin expression was investigated using a murine chondroprogenitor cell line, ATDC5, and bovine chondrocytes isolated from superficial and middle/deep zones of femoral cartilage. ATDC5 cells and bovine chondrocytes were cultured in micromass under different oxygen tensions (21%, 5%, and 1%). ATDC5 cells and middle/deep zone chondrocytes that initially had low lubricin expression levels were also cultured with or without transforming growth factor (TGF)-β1. Quantitative reverse transcription (RT)-PCR was used to determine lubricin and chondrogenic marker gene mRNA levels and immunohistochemistry was used to assess lubricin protein expression. Explant cartilage plugs cultured under different oxygen tensions were also subjected to immunohistological analysis for lubricin. HIF-1α gene silencing was achieved by electroporatic transfer into ATDC5 cells. A low oxygen tension reduced lubricin gene expression levels in bovine superficial chondrocytes, TGF-β1-treated middle/deep zone chondrocytes, and TGF-β1-treated ATDC5 cells. Lubricin expression in explant cartilage was also suppressed under hypoxia. HIF-1α gene silencing in ATDC5 cells attenuated the lubricin expression response to the oxygen tension. These results corroborate with previous studies that the oxygen tension regulates lubricin gene expression and suggest that HIF-1α plays an important role in this regulation. The normal distribution of lubricin in articular cartilage may be due to the hypoxic oxygen environment of cartilage as it is an avascular tissue. An oxygen tension gradient may be a key factor for engineering cartilage tissue with a layered morphology.

  13. 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.

  14. 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

  15. 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 realis......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....

  16. 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.

  17. Saturn ring temperature variations with approaching ring equinox

    Science.gov (United States)

    Spilker, L.; Leyrat, C.; Flandes, A.; Altobelli, N.; Pilorz, S.; Ferrari, C.; Edgington, S.

    2009-04-01

    Cassini's Composite Infrared Spectrometer (CIRS) has acquired a wide-ranging set of thermal measurements of Saturn's main rings (A, B, C and Cassini Division) at solar elevations ranging from less than one degree to 24 degrees. At Saturn equinox in August the solar elevation angle will reach zero as the sun traverses from the south to north side of the rings. For the data acquired to date, temperatures were retrieved for the lit and unlit rings over a variety of ring geometries that include solar elevation, as well as spacecraft elevation, phase angle and local hour angle. To first order, the largest temperature changes on the lit face of the rings are driven by variations in phase angle while differences in temperature with changing spacecraft elevation and local time are a secondary effect. Decreasing ring temperature with decreasing solar elevation are observed for both the lit and unlit faces of the rings after phase angle and local time effects are taken into account. As the solar elevation continues to decrease, the ring temperatures are decreasing in a non-linear fashion. The difference in temperature between the lit and unlit sides of the rings is decreasing also with decreasing solar elevation. Using ring thermal models developed by Leyrat we extrapolate to the expected minimum ring temperatures at equinox for our planned CIRS ring observations. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA and at CEA Saclay supported by the "Programme National de Planetologie". Copyright 2009 California Institute of Technology. Government sponsorship acknowledged.

  18. Tension Distribution in a Tendon-Driven Robotic Finger

    Science.gov (United States)

    Abdallah, Muhammad E. (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor)

    2013-01-01

    A method is provided for distributing tension among tendons of a tendon-driven finger in a robotic system, wherein the finger characterized by n degrees of freedom and n+1 tendons. The method includes determining a maximum functional tension and a minimum functional tension of each tendon of the finger, and then using a controller to distribute tension among the tendons, such that each tendon is assigned a tension value less than the maximum functional tension and greater than or equal to the minimum functional tension. The method satisfies the minimum functional tension while minimizing the internal tension in the robotic system, and satisfies the maximum functional tension without introducing a coupled disturbance to the joint torques. A robotic system includes a robot having at least one tendon-driven finger characterized by n degrees of freedom and n+1 tendons, and a controller having an algorithm for controlling the tendons as set forth above.

  19. INSIGHTS INTO THE MECHANICS OF CYTOKINETIC RING ASSEMBLY USING 3D MODELING.

    Science.gov (United States)

    Bidone, Tamara Carla; Tang, Haosu; Vavylonis, Dimitrios

    During fission yeast cytokinesis, actin filaments nucleated by cortical formin Cdc12 are captured by myosin motors bound to a band of cortical nodes. The myosin motors exert forces that pull nodes together into a contractile ring. Cross-linking interactions help align actin filaments and nodes into a single bundle. Mutations in the myosin motor domain and changes in the concentration of cross-linkers alpha-actinin and fimbrin alter the morphology of the condensing network, leading to clumps, rings or extended meshworks. How the contractile tension developing during ring formation depends on the interplay between network morphology, myosin motor activity, cross-linking and actin filament turnover remains to be elucidated. We addressed this question using a 3D computational model in which semiflexible actin filaments (represented as beads connected by springs) grow from formins, can be captured by myosin in neighboring nodes, and get cross-linked with one another through an attractive interaction. We identify regimes of tension generation between connected nodes under a wide set of conditions regarding myosin dynamics and strength of cross-linking between actin filaments. We find conditions that maximize circumferential tension, correlate them with network morphology and propose experiments to test these predictions. This work addresses "Morphogenesis of soft and living matter" using computational modeling to simulate cytokinetic ring assembly from the key molecular mechanisms of viscoelastic cross-linked actin networks that include active molecular motors.

  20. TBK1 duplication is found in normal tension and not in high tension ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 95; Issue 2. TBK1 duplication is found in normal tension and not in high tension glaucoma patients of Indian origin. LALIT KAURANI MANSI VISHAL JHARNA RAY ABHIJIT SEN KUNAL RAY ARIJIT MUKHOPADHYAY. RESEARCH NOTE Volume 95 Issue 2 June 2016 pp 459- ...

  1. TBK1 duplication is found in normal tension and not in high tension ...

    Indian Academy of Sciences (India)

    Supplementary data: TBK1 duplication is found in normal tension and not in high tension glaucoma patients of Indian origin. Lalit Kaurani, Mansi Vishal, Jharna Ray, Abhijit Sen, Kunal Ray and Arijit Mukhopadhyay. J. Genet. 95, 459–461. Table 1. Intraocular pressure of NTG and HTG patients. Total. Mean IOP. Mean IOP ...

  2. Ring Image Analyzer

    Science.gov (United States)

    Strekalov, Dmitry V.

    2012-01-01

    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  3. 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

  4. 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

  5. Percutaneous tension band wiring for patellar fractures.

    Science.gov (United States)

    Rathi, Akhilesh; Swamy, M K S; Prasantha, I; Consul, Ashu; Bansal, Abhishek; Bahl, Vibhu

    2012-08-01

    To evaluate outcome of percutaneous tension band wiring for transverse fractures of the patella. 16 men and 7 women aged 27 to 65 (mean, 40) years underwent percutaneous tension band wiring for transverse fractures of the patella with a displacement of >3 mm. Pain, operating time, mobility, functional score, and complications were evaluated. 20 patients underwent successful percutaneous tension band wiring. The remaining 3 patients in whom closed reduction failed underwent open reduction and tension band wiring. The mean operating time was 46 (range, 28-62) minutes. The mean follow-up period was 20 (range, 15-30) months. At the latest follow-up, all patients had regained full extension. The objective score was excellent in 20 patients and good in 3, whereas the subjective score was excellent in 17, good in 5, and fair in one. All patients had radiological union at week 8. One patient had patellofemoral arthritis (secondary to a postoperative articular step). Two patients developed superficial infections, which resolved after antibiotic therapy. Mean thigh muscle wasting was 0.7 (range, 0.4-1) cm. Three patients encountered hardware problems (impingement/irritation of the skin over the knee) necessitating implant removal. Percutaneous tension band wiring is a viable option for transverse fractures of the patella.

  6. On thickness of Saturn rings

    International Nuclear Information System (INIS)

    Brahic, Andre; Laques, Pierre; Lecacheux, Jean; Servan, Bernard; Despiau, Raymond; Michet, Daniel; Renard, Leopold

    1980-01-01

    Electronographic plates of Saturn were taken during the transit of the Earth through the ring plane. Observing conditions were more favorable than those prevailing in 1966. Thanks to the quality of the detectors and the telescopes, it has been possible to make a more precise photometric determination of the brightness of the ring seen edge on and to measure the brightness variation with respect to the distance to the center of the planet. Extrapolating to the case where the elevation of the Earth above the ring plane is strictly zero, we deduce an apparent photometric ring thickness equal to 1.5+-0.3 km. For an homogeneous layer of small particles colliding inelastically, theory predicts a thickness of the order of a few particles radii, i.e. a few tens of meters. The observed brightness could be explained by the E ring, the brightness of large chunks, condensations and warping of the ring [fr

  7. On relation between the quark-gluon bag surface tension and the colour tube string tension

    International Nuclear Information System (INIS)

    Bugaev, K.A.; Zinovjev, G.M.

    2010-01-01

    We revisit the bag phenomenology of deconfining phase transition aiming to replenish it by introducing systematically the bag surface tension. Comparing the free energies of such bags and the strings confining the static quark-antiquark pair, we express the string tension in terms of the bag surface tension and the bulk pressure in order to estimate the bag characteristics using the lattice QCD (LQCD) data. Our analysis of the bag entropy density demonstrates that the surface tension coefficient is amazingly negative at the cross-over (continuous transition). The approach developed allows us to naturally account for an origin of a pronounced maximum (observed in the LQCD studies) in the behaviour of heavy quark-antiquark pair entropy. The vicinity of the (tri-)critical endpoint is also analyzed to clarify the meaning of vanishing surface tension coefficient.

  8. Saturn's Rings and Associated Ring Plasma Cavity: Evidence for Slow Ring Erosion

    Science.gov (United States)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

    2017-01-01

    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C- ring, leading to field-aligned plasma transport to Saturns ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma fountains. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >10(exp 9) years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

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

    Science.gov (United States)

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

    2014-03-01

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

  10. Caustic rings of dark matter

    International Nuclear Information System (INIS)

    Sikivie, P.

    1997-01-01

    It is shown that the infall of collisionless dark matter onto isolated galaxies produce a series of caustic rings in the halo dark matter distribution. The properties of these caustics are investigated. It is found in particular that the density profile of the caustic behaves as the inverse distance to the ring. Bumps in the rotation curve of NGC 3198 are interpreted as due to caustic rings of dark matter

  11. Homologues of Genetic Transformation DNA Import Genes Are Required for Rhodobacter capsulatus Gene Transfer Agent Recipient Capability Regulated by the Response Regulator CtrA.

    Science.gov (United States)

    Brimacombe, Cedric A; Ding, Hao; Johnson, Jeanette A; Beatty, J Thomas

    2015-08-01

    Gene transfer agents (GTAs) morphologically resemble small, double-stranded DNA (dsDNA) bacteriophages; however, their only known role is to package and transfer random pieces of the producing cell genome to recipient cells. The best understood GTA is that of Rhodobacter capsulatus, termed RcGTA. We discovered that homologues of three genes involved in natural transformation in other bacteria, comEC, comF, and comM, are essential for RcGTA-mediated gene acquisition. This paper gives genetic and biochemical evidence that RcGTA-borne DNA entry into cells requires the ComEC and ComF putative DNA transport proteins and genetic evidence that putative cytoplasmic ComM protein of unknown function is required for recipient capability. Furthermore, the master regulator of RcGTA production in bacterial horizontal gene transfer mechanisms, where donor DNA is packaged in transducing phage-like particles and recipient cells take up DNA using natural transformation-related machinery. Both of these differentiated subsets of a culture population, donors and recipients, are dependent on the same response regulator, CtrA. Horizontal gene transfer (HGT) is a major driver of bacterial evolution and adaptation to environmental stresses. Traits such as antibiotic resistance or metabolic properties can be transferred between bacteria via HGT; thus, HGT can have a tremendous effect on the fitness of a bacterial population. The three classically described HGT mechanisms are conjugation, transformation, and phage-mediated transduction. More recently, the HGT factor GTA was described, where random pieces of producing cell genome are packaged into phage-like particles that deliver DNA to recipient cells. In this report, we show that transport of DNA borne by the R. capsulatus RcGTA into recipient cells requires key genes previously thought to be specific to natural transformation pathways. These findings indicate that RcGTA combines central aspects of phage-mediated transduction and natural

  12. 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

  13. 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

  14. Integrated Ring Resonators The Compendium

    CERN Document Server

    Rabus, Dominik G

    2007-01-01

    The optical filter, which has emerged in the last few years in integrated optics, is resonator based. Ring-resonator filters do not require facets or gratings for optical feedback and are thus particularly suited for monolithic integration with other components. Ring resonators find applications not only in optical networks, but also as sensors. The required passband shape of ring resonator-filters can be custom designed by the use of configurations of various ring coupled resonators. This book describes the current state-of-the-art on these devices with respect to design, fabrication and application.

  15. 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....

  16. Tension Stiffened and Tendon Actuated Manipulator

    Science.gov (United States)

    Doggett, William R. (Inventor); Dorsey, John T. (Inventor); Ganoe, George G. (Inventor); King, Bruce D. (Inventor); Jones, Thomas C. (Inventor); Mercer, Charles D. (Inventor); Corbin, Cole K. (Inventor)

    2015-01-01

    A tension stiffened and tendon actuated manipulator is provided performing robotic-like movements when acquiring a payload. The manipulator design can be adapted for use in-space, lunar or other planetary installations as it is readily configurable for acquiring and precisely manipulating a payload in both a zero-g environment and in an environment with a gravity field. The manipulator includes a plurality of link arms, a hinge connecting adjacent link arms together to allow the adjacent link arms to rotate relative to each other and a cable actuation and tensioning system provided between adjacent link arms. The cable actuation and tensioning system includes a spreader arm and a plurality of driven and non-driven elements attached to the link arms and the spreader arm. At least one cable is routed around the driven and non-driven elements for actuating the hinge.

  17. Tensions between Teams and Their Leaders

    Directory of Open Access Journals (Sweden)

    J. David Johnson

    2016-10-01

    Full Text Available The intersection of teamwork and leadership results in tensions, dilemmas, and paradoxes for both individuals and for institutions such as simultaneously empowering individuals at the same time it frustrates them when our naive, cultural understanding of leadership centralizes power and values leaders who can impose their will and vision on others. Perhaps the fundamental paradox of teamwork and leadership is that the more leadership is focused on an individual the less likely a team’s potential will be realized. Six specific domains where tensions arise are: at team boundaries; culture; who is in charge, rationality/cognition; diversity; and collaborations. Three approaches - clarifying different levels of analysis, temporal factors, and overarching concepts - to resolving tensions are discussed. New conceptions of leadership and the importance of the larger cultural frame within which they are embedded are needed for the management of technology and innovation.

  18. Residual Stress State in Single-Edge Notched Tension Specimen Caused by the Local Compression Technique

    Directory of Open Access Journals (Sweden)

    Huang Yifan

    2016-12-01

    Full Text Available Three-dimensional (3D finite element analyses (FEA are performed to simulate the local compression (LC technique on the clamped single-edge notched tension (SE(T specimens. The analysis includes three types of indenters, which are single pair of cylinder indenters (SPCI, double pairs of cylinder indenters (DPCI and single pair of ring indenters (SPRI. The distribution of the residual stress in the crack opening direction in the uncracked ligament of the specimen is evaluated. The outcome of this study can facilitate the use of LC technique on SE(T specimens.

  19. Tissue oxygen tension in the stria vascularis.

    Science.gov (United States)

    Nagahara, K; Miyake, Y; Aoyama, T; Ogino, F

    1988-01-01

    Tissue oxygen tension in the stria vascularis was successfully measured in cats using the polarographic technique. A correlation study using the differential coefficient between oxygen tension in the stria vascularis and systemic blood pressure proved that vascular autoregulation is present in the mean systemic blood pressure range between 40 and 80 mmHg. The anatomical findings and the response patterns to different gas inhalations indicated that the type of vascular regulation present is more closely related to chemical control than to auto-regulation.

  20. Coiffured black rings

    Science.gov (United States)

    Bena, Iosif; Ross, Simon F.; Warner, Nicholas P.

    2014-08-01

    We describe a new type of hair on supersymmetric black string and black ring solutions, which produces the largest known violation of black hole uniqueness, parameterized by an arbitrary function and hence an infinite number of continuous parameters. The new solutions can have non-trivial density profiles for the electric fields along the horizon, and yet have a geometry that is regular, although generically not infinitely differentiable, at the horizon. Both neutral and charged probes can cross the horizon without experiencing divergent forces. We also find restricted examples, parameterized by a few arbitrary continuous parameters, where the charge densities fluctuate but the metric does not and hence is completely differentiable. Our new class of solutions owes its existence to a mechanism reminiscent of the Q-ball: in the simplest examples the metric has more symmetry than the matter that supports it.

  1. Ring-constrained Join

    DEFF Research Database (Denmark)

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

    2008-01-01

    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....... 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...... from the conventional distance joins and closest pairs problems. We are not aware of efficient processing algorithms for RCJ in the literature. A brute-force solution requires computational cost quadratic to input size and it does not scale well for large datasets. In view of this, we develop efficient...

  2. On separable extensions of group rings and quaternion rings

    Directory of Open Access Journals (Sweden)

    George Szeto

    1978-01-01

    Full Text Available The purposes of the present paper are (1 to give a necessary and sufficient condition for the uniqueness of the separable idempotent for a separable group ring extension RG(R may be a non-commutative ring, and (2 to give a full description of the set of separable idempotents for a quaternion ring extension RQ over a ring R, where Q are the usual quaternions i,j,k and multiplication and addition are defined as quaternion algebras over a field. We shall show that RG has a unique separable idempotent if and only if G is abelian, that there are more than one separable idempotents for a separable quaternion ring RQ, and that RQ is separable if and only if 2 is invertible in R.

  3. Epidithiodiketopiperazines: Strain-Promoted Thiol-Mediated Cellular Uptake at the Highest Tension.

    Science.gov (United States)

    Zong, Lili; Bartolami, Eline; Abegg, Daniel; Adibekian, Alexander; Sakai, Naomi; Matile, Stefan

    2017-05-24

    The disulfide dihedral angle in epidithiodiketopiperazines (ETPs) is near 0°. Application of this highest possible ring tension to strain-promoted thiol-mediated uptake results in efficient delivery to the cytosol and nucleus. Compared to the previous best asparagusic acid (AspA), ring-opening disulfide exchange with ETPs occurs more efficiently even with nonactivated thiols, and the resulting thiols exchange rapidly with nonactivated disulfides. ETP-mediated cellular uptake is more than 20 times more efficient compared to AspA, occurs without endosomal capture, depends on temperature, and is "unstoppable" by inhibitors of endocytosis and conventional thiol-mediated uptake, including siRNA against the transferrin receptor. These results suggest that ETP-mediated uptake not only maximizes delivery to the cytosol and nucleus but also opens the door to a new multitarget hopping mode of action.

  4. Solid-state ring laser gyroscope

    Science.gov (United States)

    Schwartz, S.

    The ring laser gyroscope is a rotation sensor used in most kinds of inertial navigation units. It usually consists in a ring cavity filled with a mixture of helium and neon, together with high-voltage pumping electrodes. The use of a gaseous gain medium, while resulting naturally in a stable bidirectional regime enabling rotation sensing, is however the main industrially limiting factor for the ring laser gyroscopes in terms of cost, reliability and lifetime. We study in this book the possibility of substituting for the gaseous gain medium a solid-state medium (diode-pumped Nd-YAG). For this, a theoretical and experimental overview of the lasing regimes of the solid-state ring laser is reported. We show that the bidirectional emission can be obtained thanks to a feedback loop acting on the states of polarization and inducing differential losses proportional to the difference of intensity between the counterpropagating modes. This leads to the achievement of a solid-state ring laser gyroscope, whose frequency response is modified by mode coupling effects. Several configurations, either mechanically or optically based, are then successively studied, with a view to improving the quality of this frequency response. In particular, vibration of the gain crystal along the longitudinal axis appears to be a very promising technique for reaching high inertial performances with a solid-state ring laser gyroscope. Gyrolaser à état solide. Le gyrolaser est un capteur de rotation utilisé dans la plupart des centrales de navigation inertielle. Dans sa forme usuelle, il est constitué d'une cavité laser en anneau remplie d'un mélange d'hélium et de néon pompé par des électrodes à haute tension. L'utilisation d'un milieu amplificateur gazeux, si elle permet de garantir naturellement le fonctionnement bidirectionnel stable nécessaire à la mesure des rotations, constitue en revanche la principale limitation industrielle des gyrolasers actuels en termes de coût, fiabilit

  5. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  6. Caustic rings of dark matter

    OpenAIRE

    Sikivie, Pierre

    1997-01-01

    It is shown that the infall of collisionless dark matter onto isolated galaxies produces a series of caustic rings in the halo dark matter distribution. The properties of these caustics are investigated. The density profile of the caustic is derived for a specific case. Bumps in the rotation curve of NGC 3198 are interpreted as due to caustic rings of dark matter.

  7. 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

  8. El metamodelo meditativo y cefalea tensional. The meditative metamodel and tensional headache.

    OpenAIRE

    Bestard Bizet, Rafael; Batista González, Antonio; Escobar de la Torre, José Carlos; Bestard Silva, Dalia Del Carmen

    2014-01-01

    El metamodelo meditativo y cefalea tensional. The meditative metamodel and tensional headache. Resumen. La cefalea tensional se ha convertido en un verdadero fustigador de la sociedad moderna ocasionando verdaderos estragos en la salud y en la economía colectiva e individual. Aunque se hacen ingentes esfuerzos por paliar sus nefastos efectos, estos todavía resultan insuficientes e ineficientes. El presente trabajo constituye el primer intento en nuestro país de evaluar la efectividad de la me...

  9. Transcutaneous oxygen tension in imminent foot gangrene

    DEFF Research Database (Denmark)

    Tønnesen, K H

    1978-01-01

    Transcutaneous oxygen tension at 44 degree C and maximal isotope clearance (90m Tc-pretechnetate + histramine) just proximal to the 1st toe and systolic toe blood pressure (strain gauge) were studied on a tilt table in patients with various degrees of obstructive arteriosclerotic disease. In legs...

  10. Inclusion and Participation: Working with the Tensions

    Directory of Open Access Journals (Sweden)

    Gideon Calder

    2011-12-01

    Full Text Available Democracy is crucially about inclusion: a theory of democracy must account for who is to be included in the democratic process, how, and on what terms. Inclusion, if conceived democratically, is fraught with tensions. This article identifies three such tensions, arising respectively in: (i the inauguration of the democratic public; (ii enabling equal participation; and (iii the relationship between instrumental and non-instrumental accounts of democracy’s value. In each case, I argue, rather than seeking somehow to dissolve or avoid such tensions, theories of democracy should allow us to live with their implications reflexively: to work with them. Such tensions are counter-democratic to the extent that they derail what Nancy Fraser calls “participatory parity,” under which citizens count as “full partners in social interaction.” But the extent to which they do this is not itself dependent on points of paradox in the very idea of inclusion. Such parity relies on complex factors, social and economic, which democratic institutions and procedures will not by themselves address. To achieve full democratic inclusion we must already have addressed such factors; no account of democracy itself, however finely-tuned, will do this.

  11. On the role of the string tension

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, R.; Barcelos-Neto, J. (Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Fisica)

    1991-01-10

    We study in detail the role played by the tension in the quantum algebra of constraints for bosonic and spinning strings, from the point of view of the BRST/BFV formalism. We observe why the well-known critical dimensions D=10 and D=26 can survive in the tensionless case. (orig.).

  12. Five tensions between science and democracy

    Energy Technology Data Exchange (ETDEWEB)

    Guston, D.J.

    1995-12-31

    The historical aspects of dialogue between the scientific establishments and the congress are used to illustrate and define the continuing tensions between these parties since 1880. Five areas are addressed as how best to cope and deal with the issues which in all probability will not go away. 1 ref.

  13. Coexisting tensions between the 'traditionmodernity' and the ...

    African Journals Online (AJOL)

    Coexisting tensions between the 'traditionmodernity' and the 'sustainability- integration' approaches to urban development policy and planning practices in Botswana. ... exists at several levels and manifest in urban planning's preoccupation with the physicality of spatial forms, often justified in the embracing of globalization.

  14. Surface Tension Measurements with a Smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-01-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept…

  15. Multiple Intelligences: Its Tensions and Possibilities

    Science.gov (United States)

    Eisner, Elliot W.

    2004-01-01

    This article explores the tensions between Howard Gardner's theory of multiple intelligences and current educational policies emphasizing standardized and predictable outcomes. The article situates Gardner's theory within the historical interests among psychometricians in identifying those core processes that constitute human intelligence.…

  16. The tension nose: open structure rhinoplasty approach.

    Science.gov (United States)

    Johnson, C M; Godin, M S

    1995-01-01

    The term tension nose is known to many rhinoplastic surgeons, yet confusion exists as to its precise meaning. We define the tension deformity as excessive growth of the quadrilateral cartilage, resulting in a high nasal dorsum and anterior and sometimes inferior displacement of the nasal tip cartilages. A review of the surgical literature shows that little attention has been given to the evaluation and management of this problem. We reviewed 50 consecutive primary rhinoplasty candidates and found that 46 percent had some manifestation of tension deformity that required correction at the time of surgery. The techniques of open structure rhinoplasty are ideally suited to manage the tension nose. The essence of correction is a deprojection-reprojection process. First, excessive elements of the septal cartilage and anterior nasal spine, which comprise what we have termed the nasal pedestal, are reduced, resulting in tip deprojection. Open structure methods are then employed to achieve reprojection of the domes by using cartilage grafts and suturing techniques to build strength, support, and elegance into the nasal tip.

  17. Tenure Tensions: Out in the Enchanted Forest

    Science.gov (United States)

    Tyler, Jo A.

    2010-01-01

    The tenure track in higher education represents a path shrouded in a fair degree of mystery. This essay provides the perspective of a middle-aged, second-career tenure track faculty member on the vagaries of progressing down the track as an out lesbian. Three dialectics that build tension into the process--covering-creating, evaluation-liberation,…

  18. Influence of colour symmetry on string tension

    International Nuclear Information System (INIS)

    Yukalov, V.I.; Yukalova, E.P.; Shanenko, A.A.

    1994-01-01

    The ratio of the fundamental string tension in the SU(3) pure (quarkless) gauge theory to that in the SU(2) gluonic system is estimated within a statistical model approach to the description of the QCD thermodynamics. The obtained estimation is in agreement with the lattice evaluation of the ratio. 9 refs

  19. Surface tension of aqueous electrolyte solutions. Thermodynamics

    NARCIS (Netherlands)

    Drzymala, J.; Lyklema, J.

    2012-01-01

    A thermodynamic theory is developed for obtaining the enthalpic and entropic contributions to the surface excess Gibbs energy of electrolyte solutions from the dependence of the surface tension on concentration and temperature. For elaboration, accurate activity coefficients in solution as functions

  20. Normal tension glaucoma and Alzheimer disease

    DEFF Research Database (Denmark)

    Bach-Holm, Daniella; Kessing, Svend Vedel; Mogensen, Ulla

    2012-01-01

    PURPOSE: To investigate whether normal tension glaucoma (NTG) is associated with increased risk of developing dementia/Alzheimer disease (AD). METHODS: A total of 69 patients with NTG were identified in the case note files in the Glaucoma Clinic, University Hospital of Copenhagen (Rigshospitalet...

  1. Tension Builds over AFT Reform Agenda

    Science.gov (United States)

    Sawchuk, Stephen

    2012-01-01

    Can a teachers' union successfully be both a hardball-playing defender of its rights and a collaborative force for the common good? It is both a question of philosophy and, increasingly, one of policy direction for the American Federation of Teachers (AFT), whose biennial convention in Detroit showed delegates grappling with the tension between…

  2. Educational Leadership: Key Challenges and Ethical Tensions

    Science.gov (United States)

    Duignan, Patrick

    2007-01-01

    "Educational Leadership" is a major research book on contemporary leadership challenges for educational leaders. In this groundbreaking new work, educational leaders in schools, including teachers, are provided with ways of analysing and resolving common but complex leadership challenges. Ethical tensions inherent in these challenges are…

  3. 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.

  4. Burnside Rings of Fusion Systems

    DEFF Research Database (Denmark)

    Reeh, Sune Precht

    In this thesis we study the interactions between saturated fusion systems and group actions of the underlying p-groups. For a saturated fusion system F on a finite p-group S we construct the Burnside ring of F in terms of the finite S-sets whose actions respect the structure of the fusion system...... of Burnside rings given by multiplication with the characteristic idempotent, and we show that this map is the transfer map previously constructed. Applying these results, we show that for every saturated fusion system the ring generated by all (non-idempotent) characteristic elements in the p-local double...... Burnside ring is isomorphic to the p-local Burnside ring of the fusion system, and we disprove a conjecture by Park-Ragnarsson-Stancu on the composition product of fusion systems....

  5. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer

    2005-06-01

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

  6. Exploratory experimental investigations on post-tensioned structural glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik; Belis, J.

    2013-01-01

    This paper discusses two projects on post-tensioned glass beams, performed at EPFL and DTU, respectively. In these projects small scale glass beams (length of 1.5m and 1m) are post-tensioned by means of steel threaded rods tensioned at the beam ends. The purpose of post-tensioning glass beams...... is to enhance the initial failure stress of the glass and to obtain ductile (post-breakage) performance. From four-point bending tests on the post-tensioned glass beam specimens it is observed that these goals are reached. From the test results it is concluded that post-tensioning glass beams is a feasible...

  7. Transitions of tethered chain molecules under tension.

    Science.gov (United States)

    Luettmer-Strathmann, Jutta; Binder, Kurt

    2014-09-21

    An applied tension force changes the equilibrium conformations of a polymer chain tethered to a planar substrate and thus affects the adsorption transition as well as the coil-globule and crystallization transitions. Conversely, solvent quality and surface attraction are reflected in equilibrium force-extension curves that can be measured in experiments. To investigate these effects theoretically, we study tethered chains under tension with Wang-Landau simulations of a bond-fluctuation lattice model. Applying our model to pulling experiments on biological molecules we obtain a good description of experimental data in the intermediate force range, where universal features dominate and finite size effects are small. For tethered chains in poor solvent, we observe the predicted two-phase coexistence at transitions from the globule to stretched conformations and also discover direct transitions from crystalline to stretched conformations. A phase portrait for finite chains constructed by evaluating the density of states for a broad range of solvent conditions and tensions shows how increasing tension leads to a disappearance of the globular phase. For chains in good solvents tethered to hard and attractive surfaces we find the predicted scaling with the chain length in the low-force regime and show that our results are well described by an analytical, independent-bond approximation for the bond-fluctuation model for the highest tensions. Finally, for a hard or slightly attractive surface the stretching of a tethered chain is a conformational change that does not correspond to a phase transition. However, when the surface attraction is sufficient to adsorb a chain it will undergo a desorption transition at a critical value of the applied force. Our results for force-induced desorption show the transition to be discontinuous with partially desorbed conformations in the coexistence region.

  8. Endothelium-dependent effects of the ethanolic extract of the mistletoe Psittacanthus calyculatus on the vasomotor responses of rat aortic rings.

    Science.gov (United States)

    Rodríguez-Cruz, M E; Pérez-Ordaz, L; Serrato-Barajas, B E; Juárez-Oropeza, M A; Mascher, D; Paredes-Carbajal, M C

    2003-06-01

    The mistletoe Psittacanthus calyculatus (Loranthaceae) is used in Mexican traditional medicine for the treatment of hypertension. In the present study the effects of a crude ethanolic extract of this mistletoe, on the vasomotor reactivity of superfused rat aortic rings (with or without a functional endothelium) were analyzed. Either in the absence or in the presence of L-NAME or indomethacin, the extract (12.5-800 microg/ml) had no effect on the basal tone of both types of rings. In phenylephrine-precontracted rings, low concentrations of the extract (up to 300 microg/ml) induced a small additional tension development in both types of rings; however, the tension increase was slightly larger in rings having an intact endothelium. At higher concentrations (400-800 microg/ml), the extract relaxed, concentration-dependently, phenylephrine-precontracted rings with an intact endothelium. This relaxation was completely reverted by the addition of L-NAME. When the extract was applied in the continuous presence of L-NAME to phenylephrine-precontracted rings, instead of a relaxation a marked additional tension development occurred. Indomethacin did not modify the relaxation induced by the extract. The results indicate that the ethanolic extract of this mistletoe induces, predominantly, an endothelium-dependent relaxation which seems to be mediated by the synthesis/release of nitric oxide.

  9. 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)

  10. Necessary Tension in Marine Risers Tension des colonnes montantes en mer

    Directory of Open Access Journals (Sweden)

    Lubinski A.

    2006-11-01

    Full Text Available The tension governing transverse static and dynamic deflections in a riser is not the actual tension but the so-called « effective tension » The concept of effective tension and effective compression is thoroughly explained, and means for calculating effective forces are given. Numerical examples are worked out for risers whose length is between 152 m (520 ft and 920 m (3020 ft. The reciprocal of maximum bending moment of the vicinity of the hall joint is plotted versus the effective tension of the ball joint. Bending moments used were obtained through use of static and dynamic computer programs applied ta a variety of conditions of wave loading, use or non-use of buoyant moterial sleeves, etc. The most important parameters affecting riser performance are the effective La tension régissant les déflections transversales statiques et dynamiques d'une colonne montante n'est pas la tension réelle mais ce qu'on appelle « la tension effective ». Le concept de tension ou de compression effective est expliqué en détail et la façon de calculer les forces effectives est indiquée dans cet article. Des exemples numériques sont développés pour des colonnes montantes de longueur comprise entre 152 m (520 ft et 920 m (3 020 ft. On a tracé la courbe de l'inverse du moment fléchissant en fonction de la tension effective à l'articulation. Les moments fléchissants utilisés ont été calculés par ordinateur en utilisant des programmes dynamiques et statiques pour des conditions variées d'action des vagues, la colonne montante étant ou non munie de manchettes de flottabilité, etc. Les deux paramètres les plus importants qui affectent le bon comportement d'une colonne montante sont la tension effective et la charge latérale.

  11. Decay ring status / studies

    CERN Document Server

    Chance, A

    2008-01-01

    The aim of "beta-beams" is to produce highly energetic pure electron neutrino and anti-neutrino beams coming from β-decay of radioactive ions. In CERN baseline, after accelerating, the ions 6He2+ and 18Ne10+ are stored in a racetrack-shaped-decay ring until they are lost [1]. Consequently, the injection compensates the losses which occurred between two cycles. Two main loss sources were identified: the β decay and the injection scheme. After giving the optics, we will see how to protect the magnetic elements from the decay products. The injections scheme will be then detailed with its implications. We will see that the injection process makes a collimation section in energy necessary. Since the magnetic elements are not perfect, we will take into account the magnet misalignment and the multipole defects in the dipoles. We will talk then about the closed orbit distortion due to misalignment defects and about the long-term transverse stability with the dynamic aperture.

  12. JAERI storage ring JSR

    International Nuclear Information System (INIS)

    Yokomizo, H.; Harada, S.; Yanagida, K.; Yokoyama, M.; Nagai, T.; Suzuki, Y.; Mashiko, K.; Ishizaki, N.; Tayama, H.

    1990-01-01

    A design study for a next generation 8 GeV synchrotron radiation facility is in progress in Japan, and the Japan Atomic Energy Research Institute (JAERI) and Institute of Physical and Chemical Research (RIKEN) have join forces in this project. A compact electron storage ring JSR has been under construction in the linac building in the Tokai Research Establishment of JAERI to serve for studies of various kind of accelerator technologies, examination of insertion devices and beam monitors, and training of young researchers. This paper describes the lattice design, injection system, magnets, vacuum system, RF system, control system and beam monitors and presents some operation results regarding the electron beam injection and storage. The JSR is presently in good condition concerning it's fundamental functions such as injection, storage at around 150 MeV and 300 MeV, and acceleration from 150 MeV and 300 MeV. Photon induced gas desorption is still large because the vacuum chamber has not been aged heavily by synchrotron radiation. (N.K.)

  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. Particle properties and processes in Uranus' rings

    Science.gov (United States)

    Esposito, L. W.; Brahic, A.; Burns, J. A.; Marouf, Essam A.

    1991-01-01

    The particle properties and processes in the Uranian rings are analyzed from Voyager observations and ground-based data. Occultation observations of the epsilon ring are interpreted to yield an effective size of the ring particles that exceeds 70 cm, a surface mass density that exceeds 80 g/sq cm, and a ring vertical thickness greater than tens of meters for solid ice particles. The particles forming the classic rings are dark and gray, with albedo of 0.014 +/-0.004. It is argued that the small amount of dust that exists in the classical rings and between the rings in bands is created by erosion of ring particles and unseen satellites resulting from collisions and micrometeoroid bombardment. As proposed for regions of the other known ring systems, new ring material can be continually created by the destruction of small moons near the rings, which may explain the youthful appearance of the Uranian rings.

  15. The phase structure of higher-dimensional black rings and black holes

    International Nuclear Information System (INIS)

    Emparan, Roberto; Harmark, Troels; Niarchos, Vasilis; Obers, Niels A.; RodrIguez, Maria J.

    2007-01-01

    We construct an approximate solution for an asymptotically flat, neutral, thin rotating black ring in any dimension D ≥ 5 by matching the near-horizon solution for a bent boosted black string, to a linearized gravity solution away from the horizon. The rotating black ring solution has a regular horizon of topology S 1 x S D-3 and incorporates the balancing condition of the ring as a zero-tension condition. For D = 5 our method reproduces the thin ring limit of the exact black ring solution. For D ≥ 6 we show that the black ring has a higher entropy than the Myers-Perry black hole in the ultra-spinning regime. By exploiting the correspondence between ultra-spinning black holes and black membranes on a two-torus, we take steps towards qualitatively completing the phase diagram of rotating blackfolds with a single angular momentum. We are led to propose a connection between MP black holes and black rings, and between MP black holes and black Saturns, through merger transitions involving two kinds of 'pinched' black holes. More generally, the analogy suggests an infinite number of pinched black holes of spherical topology leading to a complicated pattern of connections and mergers between phases

  16. Ion Rings for Magnetic Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Greenly, John, B.

    2005-07-31

    This Final Technical Report presents the results of the program, Ion Rings for Magnetic Fusion, which was carried out under Department of Energy funding during the period August, 1993 to January, 2005. The central objective of the program was to study the properties of field-reversed configurations formed by ion rings. In order to reach this objective, our experimental program, called the Field-reversed Ion Ring Experiment, FIREX, undertook to develop an efficient, economical technology for the production of field-reversed ion rings. A field-reversed configuration (FRC) in which the azimuthal (field-reversing) current is carried by ions with gyro-radius comparable to the magnetic separatrix radius is called a field-reversed ion ring. A background plasma is required for charge neutralization of the ring, and this plasma will be confined within the ring's closed magnetic flux. Ion rings have long been of interest as the basis of compact magnetic fusion reactors, as the basis for a high-power accelerator for an inertial fusion driver, and for other applications of high power ion beams or plasmas of high energy density. Specifically, the FIREX program was intended to address the longstanding question of the contribution of large-orbit ions to the observed stability of experimental FRCs to the MHD tilt mode. Typical experimental FRCs with s {approx} 2-4, where s is the ratio of separatrix radius to ion gyro-radius, have been stable to tilting, but desired values for a fusion reactor, s > 20, should be unstable. The FIREX ring would consist of a plasma with large s for the background ions, but with s {approx} 1 for the ring ions. By varying the proportions of these two populations, the minimum proportion of large-orbit ions necessary for stability could be determined. The incorporation of large-orbit ions, perhaps by neutral-beam injection, into an FRC has been advanced for the purpose of stabilizing, heating, controlling angular momentum, and aiding the formation

  17. Static tensioning promotes hamstring tendons force relaxation more reliably than cycling tensioning.

    Science.gov (United States)

    Piedade, Sérgio Rocha; Dal Fabbro, Inácio Maria; Mischan, Martha Maria; Piedade, Cezar; Maffulli, Nicola

    2017-08-01

    Graft elongation might be a major reason for increased anterior laxity after anterior cruciate ligament (ACL) reconstruction. This study analyzed the force relaxation values and their stabilization when single strands of the gracilis and semitendinosus tendons underwent cyclic and static tensioning at 2.5% strain level, and compared the efficiency of static and cyclic tensioning in promoting force relaxation. Eighteen gracilis tendons and 18 semitendinosus tendons from nine male cadavers (mean age: 22.44years) were subjected to 10 in vitro cyclic loads at 2.5% strain level, or to a static load at 2.5% strain level. During cyclic loading, the reduction in force values tended to stabilize after the sixth cyclic load, while, in the case of static loading, this stabilization occurred by the second minute. Comparing static and cyclic loading, the gracilis tendon had similar mechanical responses in both conditions, while the semitendinosus tendon showed greater force relaxation in static compared with cyclic loading. Considering that the semitendinosus tendon is the main component of the hamstring graft, its biomechanical response to loading should guide the tensioning protocol. Therefore, static tensioning seems more effective for promoting force relaxation of the semitendinosus tendon than cyclic tensioning. The gracilis tendon showed a similar mechanical response to either tensioning protocols. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Treatment of Unstable Pelvic Ring Injuries.

    Science.gov (United States)

    Kim, Weon-Yoo

    2014-06-01

    Pelvic fractures are classified according to the stability of the pelvic ring. Unlike stable pelvic fractures, which heal without complications, unstable fractures may lead to pelvic ring deformities, which cause severe complications. An orthopedic surgeon must determine the stability of the pelvic ring by radiography and physical examination of the patient in order to ensure early, prompt treatment. This article includes anatomy of the pelvic ring, classification of pelvic ring injuries, its treatment algorithm, and corresponding cases involving unstable pelvic ring injury.

  19. 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

  20. 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

  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. Deceleration of electron rings by ions

    International Nuclear Information System (INIS)

    Schumacher, U.; Hofmann, I.; Merkel, P.; Reiser, M.

    1976-02-01

    The deceleration of intense relativistic electron rings by ions created by impact ionization in the electron rings is calculated analytically and numerically. It turns out that the stopping of rings with initial axial velocities of about β 0 = 0.1 is possible under conditions that easily can be realized experimentally in the Maryland ERA. The stopping length of the electron rings, however, depends sensitively on the initial axial ring velocities β 0 (as β 0 3 ). If the method of ring deceleration by ions is used, the reproducibility of the initial ring parameters (especially that of β 0 ) should be very good to get reliable electron ring loading and acceleration. (orig.) [de

  3. Surface and interfacial tension measurement, theory, and applications

    CERN Document Server

    Hartland, Stanley

    2004-01-01

    This edited volume offers complete coverage of the latest theoretical, experimental, and computer-based data as summarized by leading international researchers. It promotes full understanding of the physical phenomena and mechanisms at work in surface and interfacial tensions and gradients, their direct impact on interface shape and movement, and their significance to numerous applications. Assessing methods for the accurate measurement of surface tension, interfacial tension, and contact angles, Surface and Interfacial Tension presents modern simulations of complex interfacial motions, such a

  4. Tending the tensions in co-creation

    DEFF Research Database (Denmark)

    Phillips, Louise Jane

    -creation as a process of mutual learning to be valued at least as much as the outcome AND the neoliberal instrumentalisation of creativity in the service of social innovation and economic growth. The papers build on the themes of Knowledge and Power in Collaborative Research: A Reflexive Approach (Phillips, Kristiansen......Across fields of social practice, the harnessing of creativity in collaborative, dialogic processes of knowledge production is championed as a means to empower participants as agents and generate practice change. ‘Collaboration’, ‘dialogue’ and ‘participation’ have become buzzwords with a taken......-for-granted positive value. In the panel we de-romanticise “co-creation” and explore how it is enacted in particular organisational contexts, concentrating on context-specific tensions arising in the meeting between different knowledge forms and interests. These include tensions BETWEEN dialogic views of knowledge co...

  5. Surface tension and deformation in soft adhesion

    Science.gov (United States)

    Jensen, Katharine

    Modern contact mechanics was originally developed to account for the competition between adhesion and elasticity for relatively stiff deformable materials like rubber, but much softer sticky materials are ubiquitous in biology, engineering, and everyday consumer products. In such soft materials, the solid surface tension can also play an important role in resisting shape change, and significantly modify the physics of contact with soft matter. We report indentation and pull-off experiments that bring small, rigid spheres into adhesive contact with compliant silicone gel substrates, varying both the surface functionalization of the spheres and the bulk elastic properties of the gels. We map the resulting deformation profiles using optical microscopy and image analysis. We examine the substrate geometry in light of capillary and elastic theories in order to explore the interplay of surface tension and bulk elasticity in governing soft adhesion.

  6. Tensions of Teaching Media Literacy in Teacher Education

    Science.gov (United States)

    Ngomba-Westbrook, Nalova Elaine

    2013-01-01

    This study investigates the tensions a teacher educator faces in facilitating a media literacy teacher education course at the university level. Teaching tensions are conceptualized as a three-tier framework. At the first level, tensions may arise in the selection and application of pedagogies associated with critical and new/21st century…

  7. Line tension and the shape of nanodroplets.

    Science.gov (United States)

    Schimmele, L; Dietrich, S

    2009-12-01

    Various factors are discussed which might influence the equilibrium contact angle of nanodroplets placed on a solid substrate. Special emphasis is put on the possible role of the dependence of the solid-liquid interface tension [Formula: see text] on the pressure in the liquid, which in nanodrops considerably exceeds the saturation pressure. We show that certain published data regarding that dependence are meaningless because these have been deduced based on an inconsistent data analysis.

  8. Tension Tests On Bored Piles In Sand

    DEFF Research Database (Denmark)

    Krabbenhøft, Sven; Clausen, Johan; Damkilde, Lars

    2006-01-01

    The lengths of the bored piles varied from 2 m to 6 m and all were of a diameter of 140 mm. The piles were tested to failure in tension and the load-displacement relations were recorded. The investigation has shown pronounced differences between the load bearing capacities obtained by different...... design methods. The methods proposed by Fleming et al. and Reese & O’Neill seem to produce the best match with the test results....

  9. 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

  10. 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.

  11. Quasi-isochronous storage rings

    International Nuclear Information System (INIS)

    Robin, D.; Forest, E.; Pellegrini, C.; Amiry, A.

    1993-01-01

    A study is made of the single-particle dynamics of an electron-positron storage ring where the phase-slip factor is made small in order to make the ring nearly isochronous and reduce the bunch length. What is found is that a quasi-isochronous ring makes it possible to obtain a bunch length in the millimeter range, about one order of magnitude shorter than present values. In this study we have extended the work of others on isochronous storage rings by quantitatively including higher-order terms in the longitudinal equations of motion. Scaling laws are then derived relating the linear term with the next-highest-order term. These scaling laws, which are derived from a two-dimensional Hamiltonian (one dimension of position and one of momentum), establish criteria for stability. These scaling laws are then checked with full six-dimensional tracking on one particular lattice

  12. ring i familien

    DEFF Research Database (Denmark)

    Kryger, Niels

    2015-01-01

    Artiklen diskutere de senere års eksplosionsagtig interesse for børns læring i familien, og sætter et kritisk lys på den snævre investeringslogik (læring skal give afkast i form af økonomisk produktivitet), der har ledsaget mange af de programmer, der er sat i gang for at fremme denne ”familielær......Artiklen diskutere de senere års eksplosionsagtig interesse for børns læring i familien, og sætter et kritisk lys på den snævre investeringslogik (læring skal give afkast i form af økonomisk produktivitet), der har ledsaget mange af de programmer, der er sat i gang for at fremme denne...

  13. 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?

  14. 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

  15. The Composition of Saturn's Rings

    Science.gov (United States)

    Clark, R. N.; Cuzzi, J.; Filacchione, G.; Cruikshank, D. P.; Curchin, J. M.; Hoefen, T. M.; Nicholson, P. D.; Hedman, M.; Brown, R. H.; Buratti, B. J.; Baines, K. H.; Nelson, R. M.

    2008-12-01

    The Cassini spacecraft has obtained a unique collection of data about Saturn's rings, as it has observed the rings from 0 to 180 degrees in phase angle, and on both lit and unlit sides. Identification of trace contaminants, especially organic compounds, requires that spectra of the rings be uncontaminated by light from Saturn. The Cassini Visual and Infrared Mapping Spectrometer (VIMS) has acquired 0.35 to 5.1 micron, high spatial resolution spectroscopic data near the shadow of Saturn on the rings where scattered light is at a minimum. At low phase angles, the ring spectra show classic crystalline-ice spectral features except for a contaminant causing a UV absorption. VIMS spectra at 180-degree phase angle are generally flat, with only a weak positive feature at 2.86 microns in spectra of the F-ring. The general transmission decrease is due to large ring particles completely blocking light. The 2.86-micron feature indicates the presence of fine ice dust, where the ice's index of refraction is near 1.0, and light is not refracted or diffracted. There are no indications of interparticle scattering in the VIMS data at any phase angle. The lack of interparticle scattering indicates that the dense A and B rings must be very thin, approaching a monolayer, but rigorous constraints have yet to be modeled. Previous studies used tholins and amorphous carbon for the contaminant causing the UV absorption, but these models display additional absorptions and spectral structure in the near infrared not seen in VIMS data. Clark et al. (Icarus, v193, p372, 2008) modeled the changing blue peak and UV absorber observed on Phoebe, Iapetus, Hyperion, and Dione with amorphous carbon and nano-sized hematite. Nanohematite has muted spectral features compared to larger grained hematite, due to crystal field effects at the surfaces of small grains. Nanohematite has a strong UV absorber that matches the steep UV slope observed in spectra of Saturn's rings and has no strong IR absorptions

  16. Tension-induced binding of semiflexible biopolymers

    International Nuclear Information System (INIS)

    Benetatos, Panayotis; Heydt, Alice von der; Zippelius, Annette

    2014-01-01

    We investigate theoretically the effect of polymer tension on the collective behavior of reversibly binding cross-links. For this purpose, we employ a model of two weakly bending wormlike chains aligned in parallel by a tensile force, with a sequence of inter-chain binding sites regularly spaced along the contours. Reversible cross-links attach and detach at the sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and find the emergence of a free-energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the tension increases. We show that this transition is related to the cross-over between weak and strong localization of a directed polymer in a pinning potential. The cross-over to the strongly bound state can be interpreted as a mechanism for force-stiffening which exceeds the capabilities of single-chain elasticity and thus available only to reversibly cross-linked polymers. (paper)

  17. Generalized surface tension bounds in vacuum decay

    Science.gov (United States)

    Masoumi, Ali; Paban, Sonia; Weinberg, Erick J.

    2018-02-01

    Coleman and De Luccia (CDL) showed that gravitational effects can prevent the decay by bubble nucleation of a Minkowski or AdS false vacuum. In their thin-wall approximation this happens whenever the surface tension in the bubble wall exceeds an upper bound proportional to the difference of the square roots of the true and false vacuum energy densities. Recently it was shown that there is another type of thin-wall regime that differs from that of CDL in that the radius of curvature grows substantially as one moves through the wall. Not only does the CDL derivation of the bound fail in this case, but also its very formulation becomes ambiguous because the surface tension is not well defined. We propose a definition of the surface tension and show that it obeys a bound similar in form to that of the CDL case. We then show that both thin-wall bounds are special cases of a more general bound that is satisfied for all bounce solutions with Minkowski or AdS false vacua. We discuss the limit where the parameters of the theory attain critical values and the bound is saturated. The bounce solution then disappears and a static planar domain wall solution appears in its stead. The scalar field potential then is of the form expected in supergravity, but this is only guaranteed along the trajectory in field space traced out by the bounce.

  18. 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)

  19. 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...

  20. MUON STORAGE RINGS - NEUTRINO FACTORIES

    International Nuclear Information System (INIS)

    PARSA, Z.

    2000-01-01

    The concept of a muon storage ring based Neutrino Source (Neutrino Factory) has sparked considerable interest in the High Energy Physics community. Besides providing a first phase of a muon collider facility, it would generate more intense and well collimated neutrino beams than currently available. The BNL-AGS or some other proton driver would provide an intense proton beam that hits a target, produces pions that decay into muons. The muons must be cooled, accelerated and injected into a storage ring with a long straight section where they decay. The decays occurring in the straight sections of the ring would generate neutrino beams that could be directed to detectors located thousands of kilometers away, allowing studies of neutrino oscillations with precisions not currently accessible. For example, with the neutrino source at BNL, detectors at Soudan, Minnesota (1,715 km), and Gran Sasso, Italy (6,527 km) become very interesting possibilities. The feasibility of constructing and operating such a muon-storage-ring based Neutrino-Factory, including geotechnical questions related to building non-planar storage rings (e.g. at 8degree angle for BNL-Soudan, and 3degree angle for BNL-Gran Sasso) along with the design of the muon capture, cooling, acceleration, and storage ring for such a facility is being explored by the growing Neutrino Factory and Muon Collider Collaboration (NFMCC). The authors present overview of Neutrino Factory concept based on a muon storage ring, its components, physics opportunities, possible upgrade to a full muon collider, latest simulations of front-end, and a new bowtie-muon storage ring design

  1. Optofluidic ring resonator dye lasers

    Science.gov (United States)

    Sun, Yuze; Suter, Jonathan D.; Fan, Xudong

    2010-02-01

    We overview the recent progress on optofluidic ring resonator (OFRR) dye lasers developed in our research group. The fluidics and laser cavity design can be divided into three categories: capillary optofluidic ring resonator (COFRR), integrated cylindrical optofluidic ring resonator (ICOFRR), and coupled optofluidic ring resonator (CpOFRR). The COFRR dye laser is based on a micro-sized glass capillary with a wall thickness of a few micrometers. The capillary circular cross-section forms the ring resonator and supports the whispering gallery modes (WGMs) that interact evanescently with the gain medium in the core. The laser cavity structure is versatile to adapt to the gain medium of any refractive index. Owing to the high Q-factor (>109), the lasing threshold of 25 nJ/mm2 is achieved. Besides directly pump the dye molecules, lasing through fluorescence resonance energy transfer (FRET) between the donor and acceptor dye molecules is also studied in COFRR laser. The energy transfer process can be further controlled by designed DNA scaffold labeled with donor/acceptor molecules. The ICOFRR dye laser is based on a cylindrical ring resonator fused onto the inner surface of a thick walled glass capillary. The structure has robust mechanical strength to sustain rapid gain medium circulation. The CpOFRR utilizes a cylindrical ring resonator fused on the inner surface of the COFRR capillary. Since the capillary wall is thin, the individual WGMs of the cylindrical ring resonator and the COFRR couples strongly and forms Vernier effect, which provides a way to generate a single mode dye laser.

  2. 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

  3. 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

  4. Commuting Π-regular rings

    Directory of Open Access Journals (Sweden)

    Shervin Sahebi

    2014-05-01

    Full Text Available ‎$R$ is called commuting regular ring (resp‎. ‎semigroupif‎ for each $x,y\\in R$ there exists $a\\in R$‎ such that$xy=yxayx$‎. ‎In this paper‎, ‎we introduce the concept of‎‎commuting $\\pi$-regular rings (resp‎. ‎semigroups and‎‎study various properties of them.

  5. 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

  6. Standard Fibre Optic Ring LANs

    Science.gov (United States)

    Beale, N. C. L.

    1985-08-01

    The paper begins with a reminder of the particular need for standards in LANs. We then describe the requirements of High Integrity LANs. Current developments in LAN standards are then outlined. It is argued that the requirements of industrial LANs lead ideally to reconfiguring fibre optic rings, for which there are two major emerging standards. These two (IEEE 802.5 and ANSI FDDI) and the Cambridge Ring are discussed and compared. One implementation - the HILAN is discussed.

  7. Of Rings and Volcanoes

    Science.gov (United States)

    2002-01-01

    Office National d'Etudes et de Recherches Aérospatiales (ONERA) , Laboratoire d'Astrophysique de Grenoble (LAOG) and the DESPA and DASGAL laboratories of the Observatoire de Paris in France, in collaboration with ESO. The CONICA infra-red camera was built, under an ESO contract, by the Max-Planck-Institut für Astronomie (MPIA) (Heidelberg) and the Max-Planck Institut für Extraterrestrische Physik (MPE) (Garching) in Germany, in collaboration with ESO. Saturn - Lord of the rings ESO PR Photo 04a/02 ESO PR Photo 04a/02 [Preview - JPEG: 460 x 400 pix - 54k] [Normal - JPEG: 1034 x 800 pix - 200k] Caption : PR Photo 04a/02 shows the giant planet Saturn, as observed with the VLT NAOS-CONICA Adaptive Optics instrument on December 8, 2001; the distance was 1209 million km. It is a composite of exposures in two near-infrared wavebands (H and K) and displays well the intricate, banded structure of the planetary atmosphere and the rings. Note also the dark spot at the south pole at the bottom of the image. One of the moons, Tethys, is visible as a small point of light below the planet. It was used to guide the telescope and to perform the adaptive optics "refocussing" for this observation. More details in the text. Technical information about this photo is available below. This NAOS/CONICA image of Saturn ( PR Photo 04a/02 ), the second-largest planet in the solar system, was obtained at a time when Saturn was close to summer solstice in the southern hemisphere. At this moment, the tilt of the rings was about as large as it can be, allowing the best possible view of the planet's South Pole. That area was on Saturn's night side in 1982 and could therefore not be photographed during the Voyager encounter. The dark spot close to the South Pole is a remarkable structure that measures approximately 300 km across. It was only recently observed in visible light from the ground with a telescope at the Pic du Midi Observatory in the Pyrenees (France) - this is the first infrared image to

  8. Rhythmic ring-ring stacking drives the circadian oscillator clockwise.

    Science.gov (United States)

    Chang, Yong-Gang; Tseng, Roger; Kuo, Nai-Wei; LiWang, Andy

    2012-10-16

    The oscillator of the circadian clock of cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, which together generate a self-sustained ∼24-h rhythm of phosphorylation of KaiC. The mechanism propelling this oscillator has remained elusive, however. We show that stacking interactions between the CI and CII rings of KaiC drive the transition from the phosphorylation-specific KaiC-KaiA interaction to the dephosphorylation-specific KaiC-KaiB interaction. We have identified the KaiB-binding site, which is on the CI domain. This site is hidden when CI domains are associated as a hexameric ring. However, stacking of the CI and CII rings exposes the KaiB-binding site. Because the clock output protein SasA also binds to CI and competes with KaiB for binding, ring stacking likely regulates clock output. We demonstrate that ADP can expose the KaiB-binding site in the absence of ring stacking, providing an explanation for how it can reset the clock.

  9. 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

  10. Effect of Ginkgo biloba on visual field and contrast sensitivity in Chinese patients with normal tension glaucoma: a randomized, crossover clinical trial.

    Science.gov (United States)

    Guo, Xinxing; Kong, Xiangbin; Huang, Rui; Jin, Ling; Ding, Xiaohu; He, Mingguang; Liu, Xing; Patel, Mehul Chimanlal; Congdon, Nathan G

    2014-01-07

    We evaluated the effect of ginkgo biloba extract on visual field defect and contrast sensitivity in a Chinese cohort with normal tension glaucoma. In this prospective, randomized, placebo-controlled crossover study, patients newly diagnosed with normal tension glaucoma, either in a tertiary glaucoma clinic (n = 5) or in a cohort undergoing routine general physical examinations in a primary care clinic (n = 30), underwent two 4-week phases of treatment, separated by a washout period of 8 weeks. Randomization determined whether ginkgo biloba extract (40 mg, 3 times per day) or placebo (identical-appearing tablets) was received first. Primary outcomes were change in contrast sensitivity and mean deviation on 24-2 SITA standard visual field testing, while secondary outcomes included IOP and self-reported adverse events. A total of 35 patients with mean age 63.7 (6.5) years were randomized to the ginkgo biloba extract-placebo (n = 18) or the placebo-ginkgo biloba extract (n = 17) sequence. A total of 28 patients (80.0%, 14 in each group) who completed testing did not differ at baseline in age, sex, visual field mean deviation, contrast sensitivity, IOP, or blood pressure. Changes in visual field and contrast sensitivity did not differ by treatment received or sequence (P > 0.2 for all). Power to have detected a difference in mean defect as large as previously reported was 80%. In contrast to some previous reports, ginkgo biloba extract treatment had no effect on mean defect or contrast sensitivity in this group of normal tension glaucoma patients. (http://www.chictr.org number, ChiCTR-TRC-08000724).

  11. Double acting stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1986-01-01

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

  12. Insulin resistance in equine digital vessel rings: an in vitro model to study vascular dysfunction in equine laminitis.

    Science.gov (United States)

    Venugopal, C S; Eades, S; Holmes, E P; Beadle, R E

    2011-11-01

    One of the causes of equine laminitis is hyperinsulinaemia, which may be associated with endothelial dysfunction and insulin resistance of vessels. Insulin resistance can be induced in palmar digital vessels by continued exposure to insulin in vitro. The objective was to evaluate this in vitro model for future studies. Palmar digital vessel segments were collected immediately after euthanasia from horses with normal insulin/glucose blood values. Four arterial and 4 venous rings (3 mm wide) were prepared and each ring mounted in a tissue bath, containing Tyrode's solution at 37°C, 2 g tension was applied and the rings allowed to equilibrate for 45 min. Of the 4 rings of each vessel type, one was used as a control. One each of the remaining 3 rings was used for incubation with insulin (to induce resistance), wortmannin (to block PI3-kinase) and PD-098059 (to block MAP-kinase), respectively, for 30 min. After the incubation period, the rings were contracted with phenylephrine. When the response reached a plateau, a single dose of insulin was added to the baths and the response of each ring monitored for 30 min. Insulin relaxed the control rings and those treated with PD 098059 but contracted those pretreated with insulin and wortmannin. Normal relaxation responses of the rings were converted to contractions by insulin resistance. Insulin resistance was confirmed by the qualitative response of insulin-incubated and wortmannin-incubated rings. This study demonstrated successful induction of insulin resistance in both arterial and venous rings. It also suggested that the MAP-kinase pathway plays a minor role in controlling vasomotor tone under normal physiological conditions. The study suggests that the induction of insulin resistance in equine palmar digital vessel rings is reliable and provides a good in vitro model for studying the vascular insulin resistance which may occur in equine laminitis. © 2011 EVJ Ltd.

  13. 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)

  14. 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

  15. Treatment of Unstable Pelvic Ring Injuries

    OpenAIRE

    Kim, Weon-Yoo

    2014-01-01

    Pelvic fractures are classified according to the stability of the pelvic ring. Unlike stable pelvic fractures, which heal without complications, unstable fractures may lead to pelvic ring deformities, which cause severe complications. An orthopedic surgeon must determine the stability of the pelvic ring by radiography and physical examination of the patient in order to ensure early, prompt treatment. This article includes anatomy of the pelvic ring, classification of pelvic ring injuries, its...

  16. Dream of Isochronous Ring Again

    CERN Document Server

    Hama, H

    2005-01-01

    More than 20 years ago, D.A.G. Deacon proposed an isochronous storage ring for FEL to avoid bunch heating and decreasing instantaneous gain [1]. Some of low momentum compaction (alpha) operations have been carried out, and recently coherent infrared radiation are observed on a 3rd generation light source. Because the 3rd generation rings are optimized to obtain very low emittance beam, the dispersion function in the arc sections are much reduced by introducing large bending radius, so that those are very big machines. Meanwhile N.A. Vinokurov et al. recently proposed a ring type SASE FEL based on a complete isochronous bending transport [2]. At least, experimental and theoretical study of the isochronous ring so far suggests nonlinear effects resulted from higher order dispersion and chromaticity declines the "complete" isochronous system. On the other hand, in a wavelength region of THz, tolerance of the path length along a turn of the ring seems to be within our reach. A concept to preserve of a form factor...

  17. 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

  18. Temporomandibular disorders and tension-type headache.

    Science.gov (United States)

    Mongini, Franco

    2007-12-01

    Pathologies currently defined as temporomandibular disorders may be different in nature. Temporomandibular joint (TMJ) disorders and craniofacial and cervical myogenous pain (MP) are distinct pathologies but may be superimposed and share some etiologic factors. Tension-type headache (TTH) may often be associated with craniofacial and cervical pain, and the same pharmacologic and nonpharmacologic treatment may be efficacious for both. Psychiatric comorbidity (depression and/or anxiety disorder) is less frequent in sheer TMJ disorders, compared with MP and TTH. A screening for the presence of an underlying psychiatric disorder should be part of the clinical evaluation in patients suffering from headache and facial pain.

  19. Superficial tension: experimental model with simple materials

    Directory of Open Access Journals (Sweden)

    Tintori Ferreira, María Alejandra

    2012-09-01

    Full Text Available In this work appears a didactic offer based on an experimental activity using materials of very low cost, orientated to achieving that the student understand and interpret the phenomenon of superficial tension together with the importance of the modeling in sciences. It has as principal aim of education bring the student over to the mechanics of the static fluids and the intermolecular forces, combining scientific contents with questions near to the student what provides an additional motivation to the reflection of the scientific investigation.

  20. Cuerpo y subjetividad: materiales y tensiones

    OpenAIRE

    Cachorro, Gabriel

    2007-01-01

    En este artículo se efectúa un abordaje del tema cuerpo y subjetividad a través de un ejercicio exploratorio de sus materiales y tensiones. Las preguntas posibles de formular son: ¿Qué discusiones tenemos por debajo de la subjetividad corporal?, ¿cuáles son las raíces históricas de este tema?, ¿qué problemáticas lo atraviesan? La enunciación de estos interrogantes nos ayuda a establecer la posición de investigador y a explicitar los argumentos teóricos. Se desprende de esta propuest...

  1. 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

  2. Interpreting expressive performance through listener judgments of musical tension.

    Science.gov (United States)

    Farbood, Morwaread M; Upham, Finn

    2013-01-01

    This study examines listener judgments of musical tension for a recording of a Schubert song and its harmonic reduction. Continuous tension ratings collected in an experiment and quantitative descriptions of the piece's musical features, include dynamics, pitch height, harmony, onset frequency, and tempo, were analyzed from two different angles. In the first part of the analysis, the different processing timescales for disparate features contributing to tension were explored through the optimization of a predictive tension model. The results revealed the optimal time windows for harmony were considerably longer (~22 s) than for any other feature (~1-4 s). In the second part of the analysis, tension ratings for the individual verses of the song and its harmonic reduction were examined and compared. The results showed that although the average tension ratings between verses were very similar, differences in how and when participants reported tension changes highlighted performance decisions made in the interpretation of the score, ambiguity in tension implications of the music, and the potential importance of contrast between verses and phrases. Analysis of the tension ratings for the harmonic reduction also provided a new perspective for better understanding how complex musical features inform listener tension judgments.

  3. 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

  4. 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

  5. Dewetting-mediated pattern formation inside the coffee ring

    Science.gov (United States)

    Li, Weibin; Lan, Ding; Wang, Yuren

    2017-04-01

    The rearrangement of particles in the final stage of droplet evaporation has been investigated by utilizing differential interference contrast microscopy and the formation mechanism of a network pattern inside a coffee ring has been revealed. A tailored substrate with a circular hydrophilic domain is prepared to obtain thin liquid film containing monolayer particles. Real-time bottom-view images show that the evolution of a dry patch could be divided into three stages: rupture initiation, dry patch expansion, and drying of the residual liquid. A growing number of dry patches will repeat these stages to form the network patterns inside the ringlike stain. It can be shown that the suction effect promotes the rupture of the liquid film and the formation of the dry patch. The particle-assembling process is totally controlled by the liquid film dewetting and dominated by the surface tension of the liquid film, which eventually determine the ultimate deposition patterns.

  6. 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.)

  7. Shape accuracy optimization for cable-rib tension deployable antenna structure with tensioned cables

    Science.gov (United States)

    Liu, Ruiwei; Guo, Hongwei; Liu, Rongqiang; Wang, Hongxiang; Tang, Dewei; Song, Xiaoke

    2017-11-01

    Shape accuracy is of substantial importance in deployable structures as the demand for large-scale deployable structures in various fields, especially in aerospace engineering, increases. The main purpose of this paper is to present a shape accuracy optimization method to find the optimal pretensions for the desired shape of cable-rib tension deployable antenna structure with tensioned cables. First, an analysis model of the deployable structure is established by using finite element method. In this model, geometrical nonlinearity is considered for the cable element and beam element. Flexible deformations of the deployable structure under the action of cable network and tensioned cables are subsequently analyzed separately. Moreover, the influence of pretension of tensioned cables on natural frequencies is studied. Based on the results, a genetic algorithm is used to find a set of reasonable pretension and thus minimize structural deformation under the first natural frequency constraint. Finally, numerical simulations are presented to analyze the deployable structure under two kinds of constraints. Results show that the shape accuracy and natural frequencies of deployable structure can be effectively improved by pretension optimization.

  8. TBK1 duplication is found in normal tension and not in high tension ...

    Indian Academy of Sciences (India)

    Duplication in TANK-binding kinase 1 (TBK1) gene has been shown to be associated with normal tension glaucoma. (NTG), a subtype of the neurodegenerative disease glau- coma, which is the largest cause of irreversible blindness. A specific Taqman assay was used in exploring the genetic contribution of the duplication ...

  9. Nitinol Fatigue Investigation on Stent-Finish Specimens Using Tension-Tension Method

    Science.gov (United States)

    Lin, Z.; Pike, K.; Zipse, A.; Schlun, M.

    2011-07-01

    Nitinol fatigue strain limit versus both strain amplitude (range 0.25-1.25%) and mean strain (1.0, 2.0, and 4.0%) was investigated using a tension-tension method. In order to apply the fatigue testing results to a nitinol stent and evaluate stent fatigue performance, the dog-bone style specimens were processed from the same raw material common to implantable stent manufacturing, i.e., similar nitinol tubing, surface quality, and electropolished surface. To simulate a physiological environment, the tension-tension fatigue tests were conducted in water at 37 °C. This strain-controlled fatigue test was conducted with a run-out set at 106 cycles. The fatigue strain limit at 106 cycles as well as the mean strain effect and the effects of inclusions are discussed. Fatigue results appeared in a bi-modal pattern when the strain amplitude was at a level between too high, which made all specimens to fail, and too low, which allowed all specimens to survive.

  10. A polarized view on DNA under tension

    Science.gov (United States)

    van Mameren, Joost; Vermeulen, Karen; Wuite, Gijs J. L.; Peterman, Erwin J. G.

    2018-03-01

    In the past decades, sensitive fluorescence microscopy techniques have contributed significantly to our understanding of the dynamics of DNA. The specific labeling of DNA using intercalating dyes has allowed for quantitative measurement of the thermal fluctuations the polymers undergo. On the other hand, recent advances in single-molecule manipulation techniques have unraveled the mechanical and elastic properties of this intricate polymer. Here, we have combined these two approaches to study the conformational dynamics of DNA under a wide range of tensions. Using polarized fluorescence microscopy in conjunction with optical-tweezers-based manipulation of YOYO-intercalated DNA, we controllably align the YOYO dyes using DNA tension, enabling us to disentangle the rapid dynamics of the dyes from that of the DNA itself. With unprecedented control of the DNA alignment, we resolve an inconsistency in reports about the tilted orientation of intercalated dyes. We find that intercalated dyes are on average oriented perpendicular to the long axis of the DNA, yet undergo fast dynamics on the time scale of absorption and fluorescence emission. In the overstretching transition of double-stranded DNA, we do not observe changes in orientation or orientational dynamics of the dyes. Only beyond the overstretching transition, a considerable depolarization is observed, presumably caused by an average tilting of the DNA base pairs. Our combined approach thus contributes to the elucidation of unique features of the molecular dynamics of DNA.

  11. INVITED TALK: Dynamics Of Planetary Rings

    Science.gov (United States)

    Tiscareno, Matthew S.

    2011-04-01

    Planetary rings are the only nearby astrophysical disks, and the only disks that have been investigated by spacecraft (especially the Cassini spacecraft orbiting Saturn). Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 1e-7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close-range and in real-time in planetary rings. We will review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We will then review planetary rings by type. The A, B, and C rings of Saturn, plus the Cassini Division, comprise our solar system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are found both at Uranus (where they comprise the main rings entirely) and at Saturn (where they are embedded in the broad disk), and are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty rings, likely generated by embedded source bodies, are surprisingly found to sport azimuthally-confined arcs both at Saturn, Jupiter, and Neptune. Finally, every known ring system includes a substantial component of diffuse dusty rings.

  12. Tension-type headache: pain, fatigue, tension, and EMG responses to mental activation.

    Science.gov (United States)

    Bansevicius, D; Westgaard, R H; Sjaastad, O M

    1999-06-01

    Twenty patients with tension-type headache (14 chronic and 6 episodic) and 20 group-matched controls were selected for this study. They participated in a 1-hour, complex, two-choice, reaction-time test, as well as 5-minute pretest and 20-minute posttest periods. Subjects reported any pain in the forehead, temples, neck, and shoulders, as well as any feelings of fatigue and tension during the pretest, and every 10 minutes during the test and posttest by visual analog scales. Superficial electromyography was recorded simultaneously from positions representing the frontal and temporal muscles, neck (mostly splenius), and trapezius muscles. The location of pain corresponded to the position of the electrodes, but extended over a larger area. The test provoked pain in the forehead, neck, and shoulders of patients, i.e., pain scores from these regions increased significantly during the test. The pain scores continued to increase posttest. In patients, the EMG response of the trapezius (first 10 minutes of the test) was elevated relative to pretest. In controls, only the frontal muscles showed an EMG test response. Patients showed significantly higher EMG responses than controls in the neck (whole test period) and trapezius (first 10 minutes of the test period). There were significant differences in pain and fatigue scoring between patients and controls in all three periods and in tension scoring posttest. Fatigue correlated with pain, with increasing significance for all locations examined, while tension was mainly associated with the neck pain. The meaning of the variables "tension" and "fatigue" in headache, and their association with recorded muscle activity in various regions is discussed. The EMG response of the trapezius muscle to the test is discussed in comparison with similar responses observed in patients with other pain syndromes.

  13. Soft Neutrosophic Ring and Soft Neutrosophic Field

    Directory of Open Access Journals (Sweden)

    Mumtaz Ali

    2014-04-01

    Full Text Available In this paper we extend the theory of neutrosophic rings and neutrosophic fields to soft sets and construct soft neutrosophic rings and soft neutrosophic fields. We also extend neutrosophic ideal theory to form soft neutrosophic ideal over a neutrosophic ring and soft neutrosophic ideal of a soft neutrosophic ring. We have given many examples to illustrate the theory of soft neutrosophic rings and soft neutrosophic fields and display many properties of these. At the end of this paper we gave soft neutrosophic ring homomorphism.

  14. Thomson's Jumping Ring Over a Long Coil

    Science.gov (United States)

    Jeffery, Rondo N.; Amiri, Farhang

    2018-03-01

    The classic jumping ring apparatus consists of a coil with an iron core that extends out of the coil. A copper or aluminum ring placed over the iron core jumps upward when AC power is applied to the coil. In this paper we will examine a modified design of the jumping ring apparatus, called the "long-coil design." It allows the ring to jump upward or downward, depending on the starting position of the ring. These features shed significant light on the study of the force that causes the ring to jump.

  15. E-læring

    DEFF Research Database (Denmark)

    Heilesen, Simon

    2001-01-01

    E-læring er et modeord og et mantra. Undervisning bliver ikke automatisk bedre af, at der sættes et ”e-” foran. Forbedring og fornyelse af undervisningen er betinget af, at vi forstår computermediets muligheder og skaber forandring ved at tilpasse det til de undervisningsformer, vi ønsker....

  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 ...

  17. 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

  18. 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

  19. 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

  20. 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.

  1. Modification of Upper Thread Tensioner of Sewing Machine

    Science.gov (United States)

    Klouček, P.; Škop, P.

    Standard mechanical upper thread tensioner of sewing machines is more and more limited in use for industrial sewing machines due to increasing requests for quality and raising velocity of machines. If we omit mostly manual settings of force made only by sense, the most problematic things are influence of different friction coefficient of the different batch of threads and strong relation between thread tension and sewing machine velocity. The article describes the development focused to the elimination of the most significant disadvantages of a standard tensioner and mainly finding of new conception of the tensioner with electromagnetic brake, development and testing of its prototype.

  2. STRENGTH SHRINKAGE AND CREEP OF CONCRETE IN TENSION AND COMPRESSION

    Directory of Open Access Journals (Sweden)

    S A Kristiawan

    2006-01-01

    Full Text Available Strength, shrinkage and creep of concrete in tension and compression have been determined and the relationship between those properties was studied. Direct tensile tests were applied to measure those properties in tension. The relationship of creep in tension and compression was determined based on the measurement of creep at similar stress and similar stress/strength ratio. It is found that concrete deforms more in tension than in compression. Except for concrete with a higher water/cement ratio, the use of pulverised fuel ash, ground granulated blast furnace slag, superplasticizer and shrinkage reducing admixture has no effect on strength. However, they affect creep and shrinkage of concrete.

  3. Origin of line tension for a Lennard-Jones nanodroplet

    Science.gov (United States)

    Weijs, Joost H.; Marchand, Antonin; Andreotti, Bruno; Lohse, Detlef; Snoeijer, Jacco H.

    2011-02-01

    The existence and origin of line tension has remained controversial in literature. To address this issue, we compute the shape of Lennard-Jones nanodrops using molecular dynamics and compare them to density functional theory in the approximation of the sharp kink interface. We show that the deviation from Young's law is very small and would correspond to a typical line tension length scale (defined as line tension divided by surface tension) similar to the molecular size and decreasing with Young's angle. We propose an alternative interpretation based on the geometry of the interface at the molecular scale.

  4. Bending Under Tension Test with Direct Friction Measurement

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Olsson, David Dam; Chodnikiewicz, K.

    2006-01-01

    A special Bending-Under-Tension (BUT) transducer has been developed in which friction around the tool radius can be directly measured when drawing a plane sheet strip around a cylindrical tool-pin under constant back tension. The front tension, back tension and torque on the tool-pin are all...... measured directly, thus enabling accurate measurement of friction and direct determination of lubricant film breakdown for varying normal pressure, sliding speed, tool radius and tool preheat temperature. The transducer is applied in an experimental investigation focusing on limits of lubrication...... in drawing of stainless steel showing the influence of varying process conditions and the performance of different lubricants....

  5. Neurotrophic factors in tension-type headache

    Directory of Open Access Journals (Sweden)

    Renan B. Domingues

    2015-05-01

    Full Text Available Neurotrophic factors (NF are involved in pain regulation and a few studies have suggested that they may play a pathophysiological role in primary headaches. The aim of this study was to investigate NF levels in patients with tension type headache (TTH. We carried out a cross sectional study including 48 TTH patients and 48 age and gender matched controls. Beck Depression and Anxiety Inventories, and Headache Impact Test were recorded. Serum levels of NF were determined by ELISA. There were not significant differences between NF levels between TTH patients and controls. Patients with chronic and episodic TTH had not significant differences in NF levels. The presence of headache at the time of evaluation did not significantly alter the levels of NF. Depression and anxiety scores as well as headache impact did not correlate with NF levels. Our study suggest that the serum levels of NF are not altered in TTH.

  6. Cognitive functions and normal tension glaucoma.

    Science.gov (United States)

    Daveckaite, Akvile; Grusauskiene, Evelina; Petrikonis, Kestutis; Vaitkus, Antanas; Siaudvytyte, Lina; Januleviciene, Ingrida

    2017-10-01

    Only a few studies have analyzed the potential link between glaucoma and cognitive function impairment. They have found controversial results. This study aims to perform quick cognitive function assessment with clock drawing test (CDT) using two different scoring systems and compare between normal tension glaucoma (NTG) and cataract patients. Totally, 30 NTG and 30 patients with cataracts were included in a prospective, pilot study. The predrawn circle was given, and patients were asked to draw the clock showing a time of 11:10. The test was evaluated using two methods - Freund method using a 7-point scoring scale (optimal cutoff ≤4) and Rakusa using a 4-point scoring scale (optimal cutoff ≤3). The level of significance was set at P drawing. Further prospective studies are needed to investigate the CDT reliability as fast screening test of cognitive function impairment in glaucoma patients.

  7. Evolving spacetimes with purely radial tension

    Directory of Open Access Journals (Sweden)

    B. Nasre Esfahani

    2000-12-01

    Full Text Available   In this study time-dependent and spherically symmetric solutions of the Einstein field equations in an anisotropic background with a purely radial tension are presented. There exist three classes of solutions,1 An open spacetime with a wormhole at its center. 2 A conical spacetime. 3 A closed spacetime. These inhomogeneous solutions are reduced to FRW spacetimes in matter-dominated era, asymptotically. Therefore, they can be used to describe local inhomogeneities that are not considered in the standard model. For the wormhole solution. it is explicity shown that the considered matter is non-exotic, that is, it does not violate the energy conditions. Also, static solutions are studied. There is only one static solution,a conical spacetime. In this case, the matter satisfies the energy condition critically.

  8. Biaxial tension on polymer in thermoforming range

    Directory of Open Access Journals (Sweden)

    Billon N.

    2010-06-01

    Full Text Available This paper presents an experimental characterization of mechanical properties of a polyethylene terephtalate (PET resin classically used in stretch blow moulding process. We have applied on such a material a well established experimental protocol at CEMEF, including new and relevant biaxial tensile tests. The experimental set-up relative to biaxial tension will be presented and described in a first part of the paper. Furthermore, we will focus on the experimental DMTA preliminary tests which are required to estimate the resin sensibility to temperature and strain rate in linear viscoelasticity domain. Finally, we will be interested in the material large strain behaviour: biaxial tensile results are presented and discussed. Finally, such an experimental approach should allow a relevant modelling of polymer physics and mechanics; this point will not be discussed here because of a lack of time.

  9. 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...

  10. Planetary science: Shepherds of Saturn's ring

    Science.gov (United States)

    Crida, Aurélien

    2015-09-01

    Saturn's F ring is chaperoned on both sides by the tiny moons Prometheus and Pandora. Numerical simulations show that this celestial ballet can result from the collision of two aggregates that evolved out of Saturn's main rings.

  11. 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.

  12. Damage development in woven fabric composites during tension-tension fatigue

    DEFF Research Database (Denmark)

    Hansen, U.

    1999-01-01

    of the operating fatigue damage mechanism(s). Fatigue leads to a degradation of material properties. Consequently, in connection with impact induced local stress raisers, fatigue produces continuously changing non-uniform stress fields because of stress redistribution effects. Other models addressing evolution......Impacted woven fabric composites were tested in tension-tension fatigue. In contrast to results from static testing, the effects of low energy impact damage in a fatigue environment were found to be the critical element leading to failure of the specimen. This difference emphasizes the need...... to identify and understand the fatigue damage mechanism. A relatively new non-destructive inspection technique using infrared thermography was found to be a very useful tool in detecting damage initiation and growth. Furthermore, this technique supplies valuable information to the characterization...

  13. 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.

  14. 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 ...

  15. Tree-ring anomalies in Toona ciliata

    OpenAIRE

    Heinrich, Ingo; Banks, John Charles Gripper

    2006-01-01

    New increment core samples of Toona ciliata collected in the Australian tropics and subtropics compared to already existing material from the Upper Kangaroo Valley, near Sydney exhibit distinct differences in tree-ring structures. This necessitated a closer examination of the wood anatomy, possible false rings and the species’ crossdating capacity in northeast Australia. During tree-ring analysis two growth anomalies (extensive zones of narrow and indistinct rings) and three types of false ri...

  16. 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...

  17. Random Implantation of Asymmetric Intracorneal Rings

    Directory of Open Access Journals (Sweden)

    Cristina Peris-Martínez

    2014-01-01

    Full Text Available Intracorneal ring employment for treating ectasia is widespread. Although the mechanism of action of intracorneal rings in the regularization of the corneal surface after its implantation is well known in most cases, there are still many doubts. We present a case of implanted intracorneal rings, where, despite the peculiar position of the rings, the patient gains lines of visual acuity and keratoconus remains stable.

  18. Edge-on View of Saturn's Rings

    Science.gov (United States)

    1996-01-01

    TOP - This is a NASA Hubble Space Telescope snapshot of Saturn with its rings barely visible. Normally, astronomers see Saturn with its rings tilted. Earth was almost in the plane of Saturn's rings, thus the rings appear edge-on.In this view, Saturn's largest moon, Titan, is casting a shadow on Saturn. Titan's atmosphere is a dark brown haze. The other moons appear white because of their bright, icy surfaces. Four moons - from left to right, Mimas, Tethys, Janus, and Enceladus - are clustered around the edge of Saturn's rings on the right. Two other moons appear in front of the ring plane. Prometheus is on the right edge; Pandora, on the left. The rings also are casting a shadow on Saturn because the Sun was above the ring plane.BOTTOM - This photograph shows Saturn with its rings slightly tilted. The moon called Dione, on the lower right, is casting a long, thin shadow across the whole ring system due to the setting Sun on the ring plane. The moon on the upper left of Saturn is Tethys.Astronomers also are studying the unusual appearance of Saturn's rings. The bottom image displays a faint, narrow ring, the F-ring just outside the main ring, which normally is invisible from Earth. Close to the edge of Saturn's disk, the front section of rings seem brighter and more yellow than the back due to the additional lumination by yellowish Saturn.The color images were assembled from separate exposures taken August 6 (top) and November 17 (bottom), 1995 with the Wide Field Planetary Camera-2.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 data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  19. Optical fiber having wave-guiding rings

    Science.gov (United States)

    Messerly, Michael J [Danville, CA; Dawson, Jay W [Livermore, CA; Beach, Raymond J [Livermore, CA; Barty, Christopher P. J. [Hayward, CA

    2011-03-15

    A waveguide includes a cladding region that has a refractive index that is substantially uniform and surrounds a wave-guiding region that has an average index that is close to the index of the cladding. The wave-guiding region also contains a thin ring or series of rings that have an index or indices that differ significantly from the index of the cladding. The ring or rings enable the structure to guide light.

  20. Familial transmission of a ring chromosome 21

    DEFF Research Database (Denmark)

    Hertz, Jens Michael

    1987-01-01

    A ring chromosome 21 was found in a phenotypically normal mother and her son. The clinical findings in the son were bilateral retention of the testes and a slightly delayed puberty onset. Consequences of a ring formation of a chromosome 21 in phenotypically normal patients are presented...... and discussed, and the previously reported cases of familially transmitted G-group ring chromosomes are reviewed....

  1. 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.)

  2. Anomalous dark growth rings in black cherry

    Science.gov (United States)

    Robert P. Long; David W. Trimpey; Michael C. Wiemann; Susan L. Stout

    2012-01-01

    Anomalous dark growth rings have been observed in black cherry (Prunus serotina) sawlogs from northwestern Pennsylvania making the logs unsuitable for veneer products. Thirty-six cross sections with dark rings, each traceable to one of ten stands, were obtained from a local mill and sections were dated and annual ring widths were measured. One or...

  3. A Ring Construction Using Finite Directed Graphs

    Science.gov (United States)

    Bardzell, Michael

    2012-01-01

    In this paper we discuss an interesting class of noncommutative rings which can be constructed using finite directed graphs. This construction also creates a vector space. These structures provide undergraduate students connections between ring theory and graph theory and, among other things, allow them to see a ring unity element that looks quite…

  4. Laser driven structured quantum rings

    Science.gov (United States)

    Castiglia, Giuseppe; Corso, Pietro Paolo; De Giovannini, Umberto; Fiordilino, Emilio; Frusteri, Biagio

    2015-06-01

    In this work we study harmonic emission from structured quantum rings (SQRs). In SQRs, electrons trapped in two-dimensional structures are further confined by an external potential composed of N scattering centers arranged on a circle. We build a suitable one-dimensional model Hamiltonian describing this class of systems and analytically solve the associated Schödinger equation. We find that the solution can be expressed in terms of Mathieu functions and focus on the specific case of N = 6. By exactly solving the time-dependent Schödinger equation, we then show how the harmonic response to linearly polarized lasers strongly depends on the ring physical parameters. The results illustrate how the additional degrees of freedom introduced by these parameters provide important handles to control the emitted spectrum that in some cases extends into the XUV region.

  5. Fiber Ring Optical Gyroscope (FROG)

    Science.gov (United States)

    1979-01-01

    The design, construction, and testing of a one meter diameter fiber ring optical gyro, using 1.57 kilometers of single mode fiber, are described. The various noise components: electronic, thermal, mechanical, and optical, were evaluated. Both dc and ac methods were used. An attempt was made to measure the Earth rotation rate; however, the results were questionable because of the optical and electronic noise present. It was concluded that fiber ring optical gyroscopes using all discrete components have many serious problems that can only be overcome by discarding the discrete approach and adapting an all integrated optic technique that has the laser source, modulator, detector, beamsplitters, and bias element on a single chip.

  6. Behavioral Mapless Navigation Using Rings

    Science.gov (United States)

    Monroe, Randall P.; Miller, Samuel A.; Bradley, Arthur T.

    2012-01-01

    This paper presents work on the development and implementation of a novel approach to robotic navigation. In this system, map-building and localization for obstacle avoidance are discarded in favor of moment-by-moment behavioral processing of the sonar sensor data. To accomplish this, we developed a network of behaviors that communicate through the passing of rings, data structures that are similar in form to the sonar data itself and express the decisions of each behavior. Through the use of these rings, behaviors can moderate each other, conflicting impulses can be mediated, and designers can easily connect modules to create complex emergent navigational techniques. We discuss the development of a number of these modules and their successful use as a navigation system in the Trinity omnidirectional robot.

  7. Subluxation of the crystalline lens: a no-ring approach.

    Science.gov (United States)

    Rodrigues, Antonio Carlos L; Trivedi, Rupal H; Wilson, M Edward

    2012-01-01

    To report the surgical technique and outcomes of a no-ring approach to posterior chamber intraocular lens (IOL) implantation in children and young adults with subluxation of the crystalline lens. A three-piece 5.5-mm hydrophobic acrylic IOL was implanted in which the optic and one haptic were inside the capsular bag and the other haptic was in the ciliary sulcus. The implantations were done in 13 eyes of 10 patients with lens subluxation. One haptic was fixated in the ciliary sulcus by passing it through an operculum-shaped opening in the capsular bag edge, made between 2 and 3 clock hours, clockwise from the middle point of the subluxated area. The mean age of the 10 patients was 12.61 ± 8.04 years and the mean follow-up was 21.38 ± 11.29 months. The mean preoperative and postoperative best-corrected visual acuity (BCVA) was 1.15 ± 0.58 and 0.37 ± 0.17 logarithm of the minimum angle of resolution, respectively, in 11 measured eyes. The postoperative BCVA was 20/40 or better in 4 eyes (36.36%), between 20/40 and 20/60 in 6 eyes (54.54%), and between 20/80 and 20/100 in 1 eye (9.09%). The BCVA improved in all eyes. Postoperative IOL decentration between 1.0 and 1.5 mm occurred in 3 of 13 eyes (23.08%). The results indicate that the no-ring technique allows centration of an IOL implanted into a subluxated capsular bag without using capsule tension rings. Copyright 2012, SLACK Incorporated.

  8. Corrosion resistance of grouted post-tensioning systems : [summary].

    Science.gov (United States)

    2013-08-01

    The increased popularity of post-tensioned bridge construction in the United States has led to concerns about corrosion and its impact on the life cycle of these bridges. Although the vast majority of post-tensioned bridges in the United States have ...

  9. Rapid cable tension estimation using dynamic and mechanical properties

    Science.gov (United States)

    Martínez-Castro, Rosana E.; Jang, Shinae; Christenson, Richard E.

    2016-04-01

    Main tension elements are critical to the overall stability of cable-supported bridges. A dependable and rapid determination of cable tension is desired to assess the state of a cable-supported bridge and evaluate its operability. A portable smart sensor setup is presented to reduce post-processing time and deployment complexity while reliably determining cable tension using dynamic characteristics extracted from spectral analysis. A self-recording accelerometer is coupled with a single-board microcomputer that communicates wirelessly with a remote host computer. The portable smart sensing device is designed such that additional algorithms, sensors and controlling devices for various monitoring applications can be installed and operated for additional structural assessment. The tension-estimating algorithms are based on taut string theory and expand to consider bending stiffness. The successful combination of cable properties allows the use of a cable's dynamic behavior to determine tension force. The tension-estimating algorithms are experimentally validated on a through-arch steel bridge subject to ambient vibration induced by passing traffic. The tension estimation is determined in well agreement with previously determined tension values for the structure.

  10. Tension band wiring fi xation is associated with good functional ...

    African Journals Online (AJOL)

    Background: Tension band wiring (TBW) is a widely accepted technique for olecranon fractures. Various investigators have reported a significant rate of complications especially hardware prominence. The purpose of this study was to determine the clinical and radiological outcome after tension band wiring of olecranon ...

  11. College Learning and Teaching: Struggling with/in the Tensions.

    Science.gov (United States)

    Child, Mark; Williams, David D.

    1996-01-01

    Tensions arising in the college classroom when a teacher attempts to change instructional practice and meets resistance are examined. It is suggested that the common response is for both teacher and students to struggle to overcome tensions entirely, which tends to reproduce the original instructional problems. Alternative approaches that can…

  12. Tensions within Teaching: An Autoethnography of an American Teacher

    Science.gov (United States)

    Tuura, Brianne Marie

    2012-01-01

    This dissertation examines the personal transformation of an American teacher as she becomes aware of the social, political, and economic tensions that exist within the American school system and the affects these tensions have on her ability to teach. As the researcher becomes more aware of power structures surrounding her, the reader is enabled…

  13. Surface tension of ionic liquids and ionic liquid solutions.

    Science.gov (United States)

    Tariq, Mohammad; Freire, Mara G; Saramago, Benilde; Coutinho, João A P; Lopes, José N Canongia; Rebelo, Luís Paulo N

    2012-01-21

    Some of the most active scientific research fronts of the past decade are centered on ionic liquids. These fluids present characteristic surface behavior and distinctive trends of their surface tension versus temperature. One way to explore and understand their unique nature is to study their surface properties. This critical review analyses most of the surface tension data reported between 2001 and 2010 (187 references).

  14. Creative tensions in youth ministry in a congregational context ...

    African Journals Online (AJOL)

    congregational approach to youth ministry could lead to certain creative tensions in youth ministry as an integral part of congregational ministry. Therefore the article identifies and discusses specific creative tensions that could be present in youth ministry where the inclusive congregational approach to youth ministry is ...

  15. Managing Tensions Between New and Existing Business Models

    DEFF Research Database (Denmark)

    Sund, Kristian J.; Bogers, Marcel; Villarroel, J. Andrei

    2016-01-01

    The search for new business models forces established companies to experiment with organizational designs — and leads to tensions that should be anticipated and carefully managed.......The search for new business models forces established companies to experiment with organizational designs — and leads to tensions that should be anticipated and carefully managed....

  16. Conducting Qualitative Data Analysis: Managing Dynamic Tensions within

    Science.gov (United States)

    Chenail, Ronald J.

    2012-01-01

    In the third of a series of "how-to" essays on conducting qualitative data analysis, Ron Chenail examines the dynamic tensions within the process of qualitative data analysis that qualitative researchers must manage in order to produce credible and creative results. These tensions include (a) the qualities of the data and the qualitative data…

  17. The Tension between Justice and Freedom in Paulo Freire's Epistemology.

    Science.gov (United States)

    Joldersma, Clarence W.

    2001-01-01

    Explores how the concept of freedom in Paulo Freire's constructivist epistemology-constituted as agentive, spontaneity-based action-is in tension with his ethical project of a pedagogy for justice, one based on responsibility and non-indifference. Resolution of this tension means reconceptualizing the grounding notion of the subject beyond a…

  18. Livslang læring

    DEFF Research Database (Denmark)

    Larson, Anne

    2016-01-01

    Pædagogisk sociologi beskæftiger sig blandt andet med de politiske rammebetingelser for opdragelse, undervisning, socialisering og uddannelse. I dette kapitel præsenteres en komparativ undersøgelse af EU’s politik med hensyn til livslang læring på den ene side, og den danske politik og lovgivning...... tilgang kaldet ‘What is the problem represented to be?’...

  19. ring og vejledning

    DEFF Research Database (Denmark)

    Ambjørn, Lone

    Formålet med kompendiet om forskellige aspekter omkring sproglig læring er at ruste de studerende til studiet på en højere læreranstalt; at højne effektiviteten i deres sproglige læringsproces; at lære de studerende at arbejde uafhængigt af underviseren; at give de studerende de nødvendige redska...

  20. 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

  1. 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...

  2. 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...

  3. Progressiv læring

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    2017-01-01

    undervisningen. • At der afsættes tid til implementeringen, og at det gøres tydeligt, at implementering tager tid. • At organiseringen af undervisningen på skolerne tilpasses, så det letter anvendelsen af principperne i Progressiv Læring. • At lærernes kompetenceudvikling er forankret på skolen både emnemæssigt...

  4. Localized type Volkmann's contracture treated with tendon transfer and tension-reduced early mobilization

    Science.gov (United States)

    Kaji, Yoshio; Nakamura, Osamu; Yamaguchi, Konosuke; Tobiume, Sachiko; Yamamoto, Tetsuji

    2017-01-01

    Abstract Rationale: For localized type Volkmann's contracture, in which degeneration of the flexor digitorum profundus (FDP) muscle to one or two fingers and restriction of finger extension occur, dissection or excision of the affected muscle is usually recommended. However, these surgical procedures need relatively wide exposure of the muscle, because the FDP muscle is in the deep portion of the forearm. Patient concerns: In this report, the case of a 35-year-old woman with localized type Volkmann's contracture is presented. Her left forearm had been compressed with an industrial roller 4 months earlier, and severe flexion contracture of the long finger and mild flexion contracture of the ring finger developed gradually. Diagnoses: localized type Volkmann's contracture. Intervention: Five months after the injury, transection of the FDP tendon to the long finger and transfer of the transected tendon to the FDP tendon to the index finger was performed after adjusting the tonus of these two tendons using a small skin incision. This procedure was followed by a tension-reduced early mobilization technique in which a tension-reduced position of the tendon suture site was maintained by taping the long finger to the volar side of the index finger, and then immediate active range of motion (ROM) exercise was started. Outcomes: Within 9 weeks after surgery, full ROM had been regained. Lessons: Using the treatment procedure presented in this case report, a good clinical result was obtained in a minimally invasive manner. PMID:28072735

  5. Evaluation of cable tension sensors of FAST reflector from the perspective of EMI

    Science.gov (United States)

    Zhu, Ming; Wang, Qiming; Egan, Dennis; Wu, Mingchang; Sun, Xiao

    2016-06-01

    The active reflector of FAST (five-hundred-meter aperture spherical radio telescope) is supported by a ring beam and a cable-net structure, in which nodes are actively controlled to form series of real-time paraboloids. To ensure the security and stability of the supporting structure, tension must be monitored for some typical cables. Considering the stringent requirements in accuracy and long-term stability, magnetic flux sensor, vibrating wire strain gauge and fiber bragg grating strain gauge are screened for the cable tension monitoring of the supporting cable-net. Specifically, receivers of radio telescopes have strict restriction on electro magnetic interference (EMI) or radio frequency interference (RFI). These three types of sensors are evaluated from the view of EMI/RFI. Firstly, these fundamentals are theoretically analyzed. Secondly, typical sensor signals are collected in the time and analyzed in the frequency domain, which shows the characteristic in the frequency domain. Finally, typical sensors are tested in an anechoic chamber to get the EMI levels. Theoretical analysis shows that Fiber Bragg Grating strain gauge itself will not lead to EMI/RFI. According to GJB151A, frequency domain analysis and test results show that for the vibrating wire strain gauge and magnetic flux sensor themselves, testable EMI/RFI levels are typically below the background noise of the anechoic chamber. FAST finally choses these three sensors as the monitoring sensors of its cable tension. The proposed study is also a reference to the monitoring equipment selection of other radio telescopes and large structures.

  6. Myosin II dynamics are regulated by tension in intercalating cells.

    Science.gov (United States)

    Fernandez-Gonzalez, Rodrigo; Simoes, Sérgio de Matos; Röper, Jens-Christian; Eaton, Suzanne; Zallen, Jennifer A

    2009-11-01

    Axis elongation in Drosophila occurs through polarized cell rearrangements driven by actomyosin contractility. Myosin II promotes neighbor exchange through the contraction of single cell boundaries, while the contraction of myosin II structures spanning multiple pairs of cells leads to rosette formation. Here we show that multicellular actomyosin cables form at a higher frequency than expected by chance, indicating that cable assembly is an active process. Multicellular cables are sites of increased mechanical tension as measured by laser ablation. Fluorescence recovery after photobleaching experiments show that myosin II is stabilized at the cortex in regions of increased tension. Myosin II is recruited in response to an ectopic force and relieving tension leads to a rapid loss of myosin, indicating that tension is necessary and sufficient for cortical myosin localization. These results demonstrate that myosin II dynamics are regulated by tension in a positive feedback loop that leads to multicellular actomyosin cable formation and efficient tissue elongation.

  7. Planck and the local Universe: quantifying the tension

    CERN Document Server

    Verde, Licia; Protopapas, Pavlos

    2013-01-01

    We use the latest Planck constraints, and in particular constraints on the derived parameters (Hubble constant and age of the Universe) for the local universe and compare them with local measurements of the same quantities. We propose a way to quantify whether cosmological parameters constraints from two different experiments are in tension or not. Our statistic, T, is an evidence ratio and therefore can be interpreted with the widely used Jeffrey's scale. We find that in the framework of the LCDM model, the Planck inferred two dimensional, joint, posterior distribution for the Hubble constant and age of the Universe is in "strong" tension with the local measurements; the odds being ~ 1:50. We explore several possibilities for explaining this tension and examine the consequences both in terms of unknown errors and deviations from the LCDM model. In some one-parameter LCDM model extensions, tension is reduced whereas in other extensions, tension is instead increased. In particular, small total neutrino masses ...

  8. Maximizing aesthetics in lateral-tension abdominoplasty and body lifts.

    Science.gov (United States)

    Lockwood, Ted E

    2004-10-01

    The high-lateral-tension abdominoplasty addresses the practical and theoretic faults of standard abdominoplasty design. Key features include limited direct undermining, increased lateral skin resection with highest-tension wound closure along lateral limbs, two-layer superficial fascial system repair, and significant truncal liposuction when needed. The high-lateral-tension design limits the unfavorable features of standard abdominoplasty and produces balanced natural aesthetic contours. The high-lateral-tension abdominoplasty is the foundation for treatment of more generalized relaxation problems in the circumferential trunk and thighs. For more significant thigh laxity and buttock ptosis, the lateral-tension abdominoplasty is combined with the transverse thigh/buttock lift to produce the lower body lift #2.

  9. Exploratory experimental investigations on post-tensioned structural glass beams

    Directory of Open Access Journals (Sweden)

    Christian Louter

    2015-05-01

    Full Text Available The mechanical response of post-tensioned glass beams is explored in this paper. This is done through bending experiments on post-tensioned glass beam specimens with either mechanically anchored or adhesively bonded steel tendons by which a beneficial pre-stress is inflicted on the glass beams. In addition, reference beams with identical geometry but without tendons are tested. From the results of the bending experiments it can be seen that the post-tensioned glass beams reach higher initial fracture loads than the reference glass beams. Furthermore, the post-tensioned glass beams develop a significant post-fracture reserve. From this it is concluded that post-tensioning a glass beam is a feasible concept, which provides increased initial fracture strength and enhanced post-fracture performance.

  10. Ethnography in community psychology: promises and tensions.

    Science.gov (United States)

    Case, Andrew D; Todd, Nathan R; Kral, Michael J

    2014-09-01

    Community psychology recognizes the need for research methods that illuminate context, culture, diversity, and process. One such method, ethnography, has crossed into multiple disciplines from anthropology, and indeed, community psychologists are becoming community ethnographers. Ethnographic work stands at the intersection of bridging universal questions with the particularities of people and groups bounded in time, geographic location, and social location. Ethnography is thus historical and deeply contextual, enabling a rich, in-depth understanding of communities that is aligned with the values and goals of community psychology. The purpose of this paper is to elucidate the potential of ethnography for community psychology and to encourage its use within the field as a method to capture culture and context, to document process, and to reveal how social change and action occur within and through communities. We discuss the method of ethnography, draw connections to community psychology values and goals, and identify tensions from our experiences doing ethnography. Overall, we assert that ethnography is a method that resonates with community psychology and present this paper as a resource for those interested in using this method in their research or community activism.

  11. Ocular Blood Flow and Normal Tension Glaucoma

    Directory of Open Access Journals (Sweden)

    Ning Fan

    2015-01-01

    Full Text Available Normal tension glaucoma (NTG is known as a multifactorial optic neuropathy characterized by progressive retinal ganglion cell death and glaucomatous visual field loss, even though the intraocular pressure (IOP does not exceed the normal range. The pathophysiology of NTG remains largely undetermined. It is hypothesized that the abnormal ocular blood flow is involved in the pathogenesis of this disease. A number of evidences suggested that the vascular factors played a significant role in the development of NTG. In recent years, the new imaging techniques, fluorescein angiography, color Doppler imaging (CDI, magnetic resonance imaging (MRI, and laser speckle flowgraphy (LSFG, have been used to evaluate the ocular blood flow and blood vessels, and the impaired vascular autoregulation was found in patients with NTG. Previous studies showed that NTG was associated with a variety of systemic diseases, including migraine, Alzheimer’s disease, primary vascular dysregulation, and Flammer syndrome. The vascular factors were involved in these diseases. The mechanisms underlying the abnormal ocular blood flow in NTG are still not clear, but the risk factors for glaucomatous optic neuropathy likely included oxidative stress, vasospasm, and endothelial dysfunction.

  12. Tension tests of concrete containment wall elements

    International Nuclear Information System (INIS)

    Schultz, D.M.; Julien, J.T.; Russel, H.G.

    1984-01-01

    Tension tests of concrete containment wall elements were conducted as part of a three-phase research program sponsored by the Electric Power Research Institute (EPRI). The objective of the EPRI experimental/analytical program is twofold. The first objective is to provide the utility industry with a test-verified analytical method for making realistic estimates of actual capacities of reinforced and prestressed concrete containments under internal over-pressurization from postulated degraded core accidents. The second objective is to determine qualitative and quantitative leak rate characteristics of typical containment cross-sections with and without penetrations. This paper covers the experimental portion to the EPRI program. The testing program for Phase 1 included eight large-scale specimens representing elements from the wall of a containment. Each specimen was 60-in (1525-mm) square, 24-in (610-mm) thick, and had full-size reinforcing bars. Six specimens were representative of prototypical reinforced concrete containment designs. The remaining two specimens represented prototypical prestressed containment designs. Various reinforcement configurations and loading arrangements resulted in data that permit comparisons of the effects of controlled variables on cracking and subsequent concrete/reinforcement/liner interaction in containment elements. Subtle differences, due to variations in reinforcement patterns and load applications among the eight specimens, are being used to benchmark the codes being developed in the analytical portion of the EPRI program. Phases 2 and 3 of the test program will examine leak rate characteristics and failure mechanisms at penetrations and structural discontinuities. (orig.)

  13. [Prozac treatment of chronic tension headache].

    Science.gov (United States)

    Voznesenskaia, T G

    1999-01-01

    The paper summarizes the experience of therapy of chronic tension type headache (TTH) with prozac (fluoxetine)--a selective serotonine reuptake inhibitor. The data are presented concerning clinical psychologic examination of 20 outpatients with chronic TTH both before and after therapy with prozac in daily dose of 20 mg during 6 weeks. Background study of the patients revealed severe depression (according to Beck's and SCL-90 scales), anxiety (Spilberger scale) and alexitimia (Toronto scale). Before the treatment, a frequency of TTH attacks was at least four times a week, the intensivity was equal to 8.9 scores according to visual analogous scale. Together with a headache there were psychopathologic and psychoautonomic manifestations. After the course of therapy the headaches disappeared completely in 25%, while considerable improvement was observed in 75% of the patients. The levels of depression, anxiety, somatization have decreased significantly too. Side effects as well as withdrawal syndrome weren't found. The role of depression in formation of chronic TTH, as well as the role of alixetimia in formation of somatizated variation of the depression were considered.

  14. India: environmental degradation, urban slums, political tension.

    Science.gov (United States)

    Chhabra, R

    1985-09-01

    This article presents an overview of stresses facing Indian society, including population pressures on land and agriculture, topsoil erosion, deforestation, flooding, unemployment, urban slums, and political unrest. Over 60% of India's arable land is estimated to suffer from environmental degradation. This has been caused both by a rapidly growing poor population seeking subsistence and by the misappropriation of natural resources by the wealthy for luxury consumption. Although deforestation is officially cited at 0.37 million acres/year, more sensitive estimates put it at 2.5 million acres/year. Deforestation and massive soil erosion have further created silting, flooding, and pollution in the plains areas of the country. Moreover, the urban population of India is expected to double in the next 15 years to reach a level of 350-400 million. At present, 20-33% of the urban population lives in slums without basic facilities. The employment crisis precipitated by increasing urbanization and migration is expected to be a major problem in the decades ahead. By the year 2000, 7.5 million people will enter the labor force annually. Demographic tension has been a major factor in recent political unrest. Language differences, inequitable access to resources, and the lack of job opportunities have been central issues in these conflicts. Unless more effective means can be found to cope simultaneously with the need to speed up development and meet the needs of a rapidly expanding population, the social and environmental fabric of India is in danger of further erosion.

  15. Muscle tension dysphonia in Vietnamese female teachers.

    Science.gov (United States)

    Nguyen, Duong Duy; Kenny, Dianna T; Tran, Ninh Duy; Livesey, Jonathan R

    2009-03-01

    There has been no published research on muscle tension dysphonia (MTD) in speakers who use a tonal language. Using a sample of 47 Northern Vietnamese female primary school teachers with MTD, we aimed to discover whether professional voice users of tonal languages presented with the same symptoms of MTD as speakers of nontonal languages and whether they presented with additional symptoms as a result of speaking a tonal language. The vocal characteristics were assessed by use of a questionnaire and expert perceptual evaluation. Laryngeal features were assessed by photolaryngoscopy. The results showed that MTD was associated with a larger number of vocal symptoms than previously reported. However, the participants did not have the same vocal symptoms reported in English speakers, for example, hard glottal attack, pitch breaks, unusual speech rate, and glottal fry. Factor analysis of the vocal symptoms revealed three factors: "vocal fatigue/hyperfunction," "physical discomfort," and "voice quality," all of which demonstrated high reliability. The major laryngeal characteristic was a glottal gap. The glottal shapes observed included: 44.7% had an incomplete closure, 29.8% a posterior gap, 12.8% an hourglass-shaped gap, 8.5% a spindle-shaped gap, and 4.3% had complete glottal closure. The findings implied a potential contribution of linguistic-specific factors and teaching-related factors to the presentation of this voice disorder in this group of teachers.

  16. Multi-wavelength studies of Saturn's rings to constrain ring particle properties and ring structure

    Science.gov (United States)

    Spilker, L.; Deau, E.; Morishima, R.; Filacchione, G.; Hedman, M.; Nicholson, P.; Colwell, J.; Bradley, T.

    2012-04-01

    A great deal can be learned about the nature of Saturn's ring particles and their regoliths by modeling the changes in brightness, color and temperature with changing viewing geometry over a wide range of wavelengths, from ultraviolet through the thermal infrared. Data from Cassini's Composite Infrared Spectrometer (CIRS), Visual and Infrared Mapping Spectrometer (VIMS), Imaging Science Subsystem (ISS) and Ultraviolet Imaging Spectrograph (UVIS) are jointly being studied using scans of the lit and unlit main rings (A, B, C and Cassini Division) at multiple geometries and solar elevations. Using multi-wavelength data sets allow us to test different thermal models by combining the effects of particle albedo, regolith grain size and surface roughness with thermal emissivity and inertia, particle spin rate and spin axis orientation. With the high spatial resolution of the Cassini data it is now possible to analyze these effects at smaller spatial scales and characterize regions such as the C ring plateaus and ringlets, where albedo differences may be present. In the CIRS data, over a range of solar elevations from -23 degrees to -8 degrees, the bulk of the temperature variations are confined primarily to phase angle. Only small temperature differences are observed with changing spacecraft elevation. Similar behavior is seen in the ISS color data. Color and temperature dependence with changing solar elevation angle are also observed. VIMS observations show that the IR ice absorption band depths are (almost) independent of phase angle, out to ~140 deg phase, suggesting that interparticle light scattering is relatively unimportant except at very high phase angles. These results imply that the individual properties of the ring particles may play a larger role than the collective properties of the rings, in particular at visible wavelengths. The temperature and color variation with phase angle may be a result of scattering within the regolith and on possibly rough surfaces

  17. Automated wireless monitoring system for cable tension using smart sensors

    Science.gov (United States)

    Sim, Sung-Han; Li, Jian; Jo, Hongki; Park, Jongwoong; Cho, Soojin; Spencer, Billie F.; Yun, Chung-Bang

    2013-04-01

    Cables are critical load carrying members of cable-stayed bridges; monitoring tension forces of the cables provides valuable information for SHM of the cable-stayed bridges. Monitoring systems for the cable tension can be efficiently realized using wireless smart sensors in conjunction with vibration-based cable tension estimation approaches. This study develops an automated cable tension monitoring system using MEMSIC's Imote2 smart sensors. An embedded data processing strategy is implemented on the Imote2-based wireless sensor network to calculate cable tensions using a vibration-based method, significantly reducing the wireless data transmission and associated power consumption. The autonomous operation of the monitoring system is achieved by AutoMonitor, a high-level coordinator application provided by the Illinois SHM Project Services Toolsuite. The monitoring system also features power harvesting enabled by solar panels attached to each sensor node and AutoMonitor for charging control. The proposed wireless system has been deployed on the Jindo Bridge, a cable-stayed bridge located in South Korea. Tension forces are autonomously monitored for 12 cables in the east, land side of the bridge, proving the validity and potential of the presented tension monitoring system for real-world applications.

  18. Surface tension of Nanofluid-type fuels containing suspended nanomaterials.

    Science.gov (United States)

    Tanvir, Saad; Qiao, Li

    2012-04-18

    The surface tension of ethanol and n-decane based nanofluid fuels containing suspended aluminum (Al), aluminum oxide (Al2O3), and boron (B) nanoparticles as well as dispersible multi-wall carbon nanotubes (MWCNTs) were measured using the pendant drop method by solving the Young-Laplace equation. The effects of nanoparticle concentration, size and the presence of a dispersing agent (surfactant) on surface tension were determined. The results show that surface tension increases both with particle concentration (above a critical concentration) and particle size for all cases. This is because the Van der Waals force between particles at the liquid/gas interface increases surface free energy and thus increases surface tension. At low particle concentrations, however, addition of particles has little influence on surface tension because of the large distance between particles. An exception is when a surfactant was used or when (MWCNTs) was involved. For such cases, the surface tension decreases compared to the pure base fluid. The hypothesis is the polymer groups attached to (MWCNTs) and the surfactant layer between a particle and the surround fluid increases the electrostatic force between particles and thus reduce surface energy and surface tension.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Interface-læring

    DEFF Research Database (Denmark)

    Thorhauge, Sally

    2015-01-01

    Interface-læring er den læringsoplevelse, der kan opstå i grænsefladen mellem to væsensforskellige læringsmiljøer, når de mødes og griber ind i hinanden. Et gymnasium og et museum er eksempler på to sådanne læringsmiljøer. Artiklen præsenterer nogle af de væsentligste resultater fra min ph.d. afh...

  4. Tension in the recent Type Ia supernovae datasets

    International Nuclear Information System (INIS)

    Wei, Hao

    2010-01-01

    In the present work, we investigate the tension in the recent Type Ia supernovae (SNIa) datasets Constitution and Union. We show that they are in tension not only with the observations of the cosmic microwave background (CMB) anisotropy and the baryon acoustic oscillations (BAO), but also with other SNIa datasets such as Davis and SNLS. Then, we find the main sources responsible for the tension. Further, we make this more robust by employing the method of random truncation. Based on the results of this work, we suggest two truncated versions of the Union and Constitution datasets, namely the UnionT and ConstitutionT SNIa samples, whose behaviors are more regular.

  5. Bending Under Tension Test with Direct Friction Measurement

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Olsson, David Dam; Chodnikiewicz, K.

    2004-01-01

    A special BUT-transducer has been developed in which friction around the tool radius can be directly measured when drawing a plane sheet strip around a cylindrical tool-pin under constant back tension. The front tension, back tension and torque on the tool-pin are all measured directly, thus...... enabling accurate measurement of friction and direct determination of lubricant film breakdown for varying normal pressure, sliding speed, tool radius and tool preheat temperature. The transducer is applied in an experimental investigation focusing on limits of lubrication in drawing of stainless steel...

  6. First-principles prediction of liquid/liquid interfacial tension

    DEFF Research Database (Denmark)

    Andersson, Martin Peter; Bennetzen, M.V.; Klamt, A.

    2014-01-01

    of groundwater aquifers contaminated by chlorinated solvents to drug delivery and a host of industrial processes. Here, we present a model for predicting interfacial tension from first principles using density functional theory calculations. Our model requires no experimental input and is applicable to liquid/liquid......The interfacial tension between two liquids is the free energy per unit surface area required to create that interface. Interfacial tension is a determining factor for two-phase liquid behavior in a wide variety of systems ranging from water flooding in oil recovery processes and remediation...

  7. Percutaneous Relief of Tension Pneumomediastinum in a Child

    International Nuclear Information System (INIS)

    Chau, Helen Hoi-lun; Kwok, Philip Chong-hei; Lai, Albert Kwok-hung; Fan, Tsz Wo; Chan, Susan Chi-hum; Miu, Ting Yat; Chan, Grace Lai-har

    2003-01-01

    The purpose of this article was to describe the experience of relieving tension pneumomediastinum by a fluoroscopic-guided percutaneous method. We inserted a percutaneous drainage catheter with a Heimlich valve under fluoroscopic guidance to relieve the tension pneumomediastinum in a 2-year-old girl who suffered from dermatomyositis with lung involvement. This allowed immediate relief without the need for surgery. The procedure was repeated for relapsed tension pneumomediastinum. Good immediate results were achieved in each attempt. We conclude that percutaneous relief of pneumomediastinum under fluoroscopic guidance can be performed safely and rapidly in patients not fit for surgery

  8. Boom and Bust Cycles in Saturn's Rings

    Science.gov (United States)

    Esposito, L. W.; Meinke, B. K.; Sremcevic, M.; Albers, N.

    2010-12-01

    Cassini UVIS occultation data show clumping in Saturn’s F ring and at the B ring outer edge, indicating aggregation and disaggregation at these locations perturbed by Mimas and Prometheus. Timescales range from hours to months. The maximum clumping lags the moon by roughly π in the forcing frame. This indicates a direct relation between the moon and the ring clumping. We propose that the collective behavior of the ring particles resembles a predator-prey system: the aggregate mean size is the prey, which feeds the velocity dispersion; conversely, increasing dispersion breaks up the aggregates. For realistic values of the parameters this creates a limit cycle behavior, as for the ecology of foxes and hares or the boom-bust economic cycle. Solving for the long-term behavior of this forced system gives a periodic response at the perturbing frequency, with a phase lag roughly consistent with the UVIS occultation measurements. We conclude that the agitation by the moons at both these locations in the F ring and at the B ring outer edge drives aggregation and disaggregation in the forcing frame. This agitation of the ring material allows fortuitous formation of solid objects from the temporary clumps, via stochastic processes like compaction, adhesion, sintering or reorganization that drives the denser parts of the aggregate to the center or ejects the lighter elements. These more persistent objects would then orbit at the Kepler rate. Such processes can create the equinox objects seen at the B ring edge and in the F ring, explain the ragged nature of those ring regions and allow for rare events to aggregate ring particles into solid objects, recycling the ring material and extending the ring lifetime.

  9. Climate-derived tensions in Arctic security.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Strickland, James Hassler

    2008-09-01

    Globally, there is no lack of security threats. Many of them demand priority engagement and there can never be adequate resources to address all threats. In this context, climate is just another aspect of global security and the Arctic just another region. In light of physical and budgetary constraints, new security needs must be integrated and prioritized with existing ones. This discussion approaches the security impacts of climate from that perspective, starting with the broad security picture and establishing how climate may affect it. This method provides a different view from one that starts with climate and projects it, in isolation, as the source of a hypothetical security burden. That said, the Arctic does appear to present high-priority security challenges. Uncertainty in the timing of an ice-free Arctic affects how quickly it will become a security priority. Uncertainty in the emergent extreme and variable weather conditions will determine the difficulty (cost) of maintaining adequate security (order) in the area. The resolution of sovereignty boundaries affects the ability to enforce security measures, and the U.S. will most probably need a military presence to back-up negotiated sovereignty agreements. Without additional global warming, technology already allows the Arctic to become a strategic link in the global supply chain, possibly with northern Russia as its main hub. Additionally, the multinational corporations reaping the economic bounty may affect security tensions more than nation-states themselves. Countries will depend ever more heavily on the global supply chains. China has particular needs to protect its trade flows. In matters of security, nation-state and multinational-corporate interests will become heavily intertwined.

  10. Cognitive functions and normal tension glaucoma

    Directory of Open Access Journals (Sweden)

    Akvile Daveckaite

    2017-01-01

    Full Text Available Purpose: Only a few studies have analyzed the potential link between glaucoma and cognitive function impairment. They have found controversial results. This study aims to perform quick cognitive function assessment with clock drawing test (CDT using two different scoring systems and compare between normal tension glaucoma (NTG and cataract patients. Methods: Totally, 30 NTG and 30 patients with cataracts were included in a prospective, pilot study. The predrawn circle was given, and patients were asked to draw the clock showing a time of 11:10. The test was evaluated using two methods – Freund method using a 7-point scoring scale (optimal cutoff ≤4 and Rakusa using a 4-point scoring scale (optimal cutoff ≤3. The level of significance was set at P < 0.05. Results: CDT result was significantly better in cataract group than in NTG group: 3.5 (2 versus 2 (2 by Freund, (P = 0.003 and 6.5 (1 versus 4.5 (2.75 by Rakusa, respectively (P = 0.004. Sixty percent (n = 18 of NTG group and 10% (n = 3 of cataract group patients completed the CDT in the specific picture manner (the short hand on 11 and the long hand between 11 and 12, (P = 0.001. Conclusions: Lower CDT results were seen in NTG patients according to two different scoring systems. NTG patients showed a specific manner of drawing. Further prospective studies are needed to investigate the CDT reliability as fast screening test of cognitive function impairment in glaucoma patients.

  11. Diffuse brain damage in normal tension glaucoma.

    Science.gov (United States)

    Giorgio, Antonio; Zhang, Jian; Costantino, Francesco; De Stefano, Nicola; Frezzotti, Paolo

    2018-01-01

    Brain changes within and beyond the visual system have been demonstrated in primary open angle glaucoma (POAG), the most common type of glaucoma. These changes have been often interpreted as a neurodegenerative process due, at least partially, to the raised intraocular pressure (IOP). In this context, normal tension glaucoma (NTG), a form of POAG with IOP acquired multimodal brain MRI in NTG patients (n = 17) and compared them with demographically matched groups of POAG patients with raised IOP (n = 17) and normal controls (NC, n = 29). Voxelwise statistics was performed with nonparametric permutation testing. Both NTG and POAG patients showed, compared to NC, significantly more gray matter atrophy in both the visual system and in nonvisual brain regions and altered diffusion tensor imaging-derived anatomical connectivity (AC; lower fractional anisotropy and/or higher diffusivities). Compared with NTG, POAG had both more atrophic visual cortex and higher axial diffusivity in nonvisual regions. Functional connectivity (FC) with respect to NC was altered in NTG at short-range level [visual network (VN), ventral attention network] and in POAG at long-range level (between secondary VN and limbic network). FC of POAG was higher than NTG in both VN and executive network. This study provides further evidence that diffuse structural and functional abnormalities across glaucoma brain may be, at least partially, independent of raised IOP and the consequent retinal degeneration. This further defines glaucoma as a condition with neurodegeneration spreading. Hum Brain Mapp 39:532-541, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. 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.

  13. Replantation of ring avulsion amputations

    Directory of Open Access Journals (Sweden)

    Sabapathy R

    2003-01-01

    Full Text Available Replantation of ring avulsion injuries is a challenge because of the long segment damage to the vessels and intrinsic damage caused to soft tissues at the proximal edge of the amputation. Eight patients with total ring avulsion amputations underwent microsurgical replantation in the period 1994 to 2002. Arterial repair was done by direct vessel suture in three patients, interposition vein grafts in two and cross anastomosis of the digital arteries in three patients. Venous anastomosis was carried out by mobilization and direct suture in seven patients and vessel transfer from the adjacent finger in one patient. Seven of the eight replantations were successful, while one patient had a partial failure. At a minimum follow-up of one year, these patients showed good functional and cosmetic recovery. All successful patients were happy with the outcome and none have requested for amputation, even those whose results were not functionally adequate. However, in addition to technical factors, it is important to evaluate the patient's motivation to undergo not only the long surgery, but also multiple secondary procedures and regular supervised physiotherapy. We also describe a simple method which prevents the soft tissues inside the degloved digit from becoming wrapped around the K wire during bony fixation, thus making one step of this technically challenging procedure a little easier.

  14. New diols with imidazoquinazoline ring

    Science.gov (United States)

    Szyszkowska, Agnieszka; Klasek, Antonin; Pawlędzio, Sylwia; Trzybiński, Damian; Woźniak, Krzysztof; Zarzyka, Iwona

    2018-02-01

    The objective of these studies was to synthesize and characterize new diols with an imidazoquinazoline ring. New diols were obtained in reactions of 2,6-bis-(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione with excess of ethylene glycol or in reaction of 1-phenyl-2H,6H-imidazo[1,5-c]quinazoline-3,5-dione with 2-M excess of ethylene oxide. The products were isolated at high yield and characterized by instrumental methods (IR, 1H- and 13C-NMR, MS-ESI, UV, TGA). The structure of 2,6-bis(2-hydroxyethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione (BEFIQ) was also investigated by single-crystal X-ray diffraction. BEFIQ crystallizes in the monoclinic P21/n space group with two molecules in the asymmetric unit of the crystal lattice. The nature of the packing of molecules in the crystal lattice of BEFIQ was investigated by Hirshfeld surface analysis. The described methods enable the synthesis of new diols with an imidazoquinazoline ring. The new diols are quite soluble in typical organic solvents. Therefore, they can be used as raw materials for the synthesis of thermally stable polymers, and they can also have biological activity.

  15. Differences of optic disc appearance between normal tension and high tension glaucoma patients

    Directory of Open Access Journals (Sweden)

    Stojčić Milan

    2011-01-01

    Full Text Available Introduction. The term glaucoma is used to cover a wide range of diseases, whose main feature is optic neuropathy. According to the level of intraocular pressure (IOP, the open angle glaucoma is arbitrarily divided into high tension glaucoma (HTG and normal tension glaucoma (NTG. Objective. The aim of this study was to investigate the differences of optic disc cup appearance between patients with NTG and HTG. Methods. Prospective study included 30 patients (60 eyes with NTG and 30 patients (60 eyes with HTG. IOP was measured by Goldmann applanation tonometry. Examination of optic disc head was performed by indirect ophthalmoscopy with Volk 90 D superfield lens through a dilated pupil to observe qualitative and quantitative parameters. Visual fields were examined in all patients with the Octopus program G1, full threshold strategy (Octopus 500 EZ, Interzeag, Switzerland. Results. Vertical form of optic disc cup was present in 11 eyes with NTG (18.3% and three eyes with HTG (5% (p<0.05. A disc with localized tissue loss (polar notching on the inferior pole was observed in eight eyes with NTG (13.3% and in one eye with HTG (1.7% (p<0.01. Uniformly enlarged, round cup was more frequent in patients with HTG than NTG: 93.3% and 68.3% respectively (p<0.05. Conclusion. The perceived differences indicate a complex multifactorial nature of glaucoma disease and a possible existence of two pathophysiological ways of optic disc changes within the same basic disease.

  16. 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.

  17. 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...

  18. Machine for winding under tension a prestressing wire

    International Nuclear Information System (INIS)

    Perez, M.A.; Thillet, Georges.

    1975-01-01

    This invention concerns a machine for winding under tension a prestressing wire or cable. It is used in the wrapping of cylindrical structures, particularly concrete vessels, for the purpose of achieving radial prestressing in them [fr

  19. System and Method for Tensioning a Robotically Actuated Tendon

    Science.gov (United States)

    Reiland, Matthew J. (Inventor); Diftler, Myron A. (Inventor)

    2013-01-01

    A tendon tensioning system includes a tendon having a proximal end and a distal end, an actuator, and a motor controller. The actuator may include a drive screw and a motor, and may be coupled with the proximal end of the tendon and configured to apply a tension through the tendon in response to an electrical current. The motor controller may be electrically coupled with the actuator, and configured to provide an electrical current having a first amplitude to the actuator until a stall tension is achieved through the tendon; provide a pulse current to the actuator following the achievement of the stall tension, where the amplitude of the pulse current is greater than the first amplitude, and return the motor to a steady state holding current following the conclusion of the pulse current.

  20. Corrosion characteristics of unprotected post-tensioning strands under stress.

    Science.gov (United States)

    2014-05-01

    An investigation was conducted to determine the effect of stress condition : and environmental exposure on corrosion of post-tensioned strands during ungrouted periods. : Exposures for periods of up to 4 weeks of stressed, as-received strand placed i...

  1. Fracture analysis of composites in high-speed tension

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Chiping; Cao, Li; Zou, Zhenzhu; Wang, Duo; Yao, Zhongkai (Harbin Institute of Technology (China))

    1989-12-01

    The fracture mechanism of composites in high-speed tension is investigated using a simplified theoretical model and results of a high-speed tension experiment on a sample of SiC-whisker-reinforced Al composite. Particular attention is given to the influence of microcracks and faults which may exist along the interfaces between the matrix and reinforcers of the composite on the strength of the composite. Results of the experimental observations show that, in high-speed tension (at 500 mm/min tensile rate), the effect of microcracks and faults along the interfaces on the composite's strength decreases in comparison with samples under conventional tension (i.e., at 0.5 mm/min tensile rate), and thus, the fracture strength of composites increases. 5 refs.

  2. Molecular dynamics calculation of the surface tension of aluminum nanodrops

    International Nuclear Information System (INIS)

    Gubin, A.S.; Botyachkova, A.I.; Dubrovskij, A.V.

    2012-01-01

    A method has been proposed for calculating the surface tension coefficient of liquid drops. The density and normal and tangential components of the stress tensor have been calculated as functions of the distance to the center of a nanodrop [ru

  3. Quantifying the BICEP2-Planck tension over gravitational waves.

    Science.gov (United States)

    Smith, Kendrick M; Dvorkin, Cora; Boyle, Latham; Turok, Neil; Halpern, Mark; Hinshaw, Gary; Gold, Ben

    2014-07-18

    The recent BICEP2 measurement of B-mode polarization in the cosmic microwave background (r = 0.2(-0.05)(+0.07)), a possible indication of primordial gravity waves, appears to be in tension with the upper limit from WMAP (r < 0.13 at 95% C.L.) and Planck (r < 0.11 at 95% C.L.). We carefully quantify the level of tension and show that it is very significant (around 0.1% unlikely) when the observed deficit of large-scale temperature power is taken into account. We show that measurements of TE and EE power spectra in the near future will discriminate between the hypotheses that this tension is either a statistical fluke or a sign of new physics. We also discuss extensions of the standard cosmological model that relieve the tension and some novel ways to constrain them.

  4. Bathing Trunk Inevus Associated with Neurofibromatosis and Raised Intracranial Tension

    Directory of Open Access Journals (Sweden)

    T.V.S Arya

    1988-01-01

    Full Text Available A 17-year-old boy had bathing trunk nevus with multiple large neurofibromata on the nevus and raised intracranial tension presenting with bilateral papilloedema and pyramidal tract sings. This combination, of features is extremely rare.

  5. CASE SERIES Traumatic tension pneumocephalus: a series of 4 ...

    African Journals Online (AJOL)

    Test

    ABSTRACT. Tension pneumocephalus is the accumulation of air in the intracranial cavity with attendant neurological changes. ... differentiated from intracranial haemorrhage. The presentation may include headache, ..... evacuation of chronic subdural hematoma : Is it a serious complication? Asian J Neurosurg. 2012 ...

  6. 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.

  7. ring og den kulturhistoriske skole

    DEFF Research Database (Denmark)

    Broström, Stig

    2007-01-01

    -forskere uddrager den grundlæggende forståelse af forholdet mellem læring og udvikling. Nemlig at læring og udvikling indgår i en dialektisk enhed og virker gensidigt ind på hinanden - dog således at læring kommer ført, den trækker udviklingen med sig og så at sige leder udviklingen. Vygotskys tese vedrørende...

  8. On the potential of large ring lasers

    Science.gov (United States)

    Stedman, G. E.; Hurst, R. B.; Schreiber, K. U.

    2007-11-01

    We describe a new ring laser with area A = 833 m 2 and update performance statistics for several such machines. Chaio and Anandan [R.Y. Chaio, J. Anandan, Gen. Relat. Gravit. 14 (1982) 515-521] judged ring lasers inferior to matter interferometers as possible detectors of gravitational waves. However, we note that geophysically interesting results have been obtained from large ring lasers and that there is still a lot of room for improvements.

  9. Arkitektur krop og læring

    DEFF Research Database (Denmark)

    Gulløv, E.; Coninck-Smith, N. D.; Pedersen, S. H.

    Når vi taler om læring, tænker vi sædvanligvis på resultatet af bevidst tilrettelagt undervisningsforløb. Megen læring sker imidlertid ubevidst via den påvirkning, omgivelserne øver på vores kroppe og vores sanser. I arkitektur, krop og læring gives en teoretisk og analytisk fremstilling af forsk......, Gebauer, Wulf, Lorentzer, Merleau-Ponty, Barth, Ehn....

  10. RRF rings which are not LRF

    Indian Academy of Sciences (India)

    All the rings we consider will be associative rings with an identity element 1 TИ 0 and all the modules considered will be unital modules. In what follows A denotes a ring, mod-A. (respectively A-mod) will denote the category of right (respectively left) A-modules. Recall (Definition 2.1 in [9]) that an A-module M is said to be ...

  11. Relatively Orthocomplemented Skew Nearlattices in Rickart Rings

    Directory of Open Access Journals (Sweden)

    Cīırulis Jānis

    2015-12-01

    Full Text Available A class of (right Rickart rings, called strong, is isolated. In particular, every Rickart *-ring is strong. It is shown in the paper that every strong Rickart ring R admits a binary operation which turns R into a right normal band having an upper bound property with respect to its natural order ≤; such bands are known as right normal skew nearlattices. The poset (R, ≤ is relatively orthocomplemented; in particular, every initial segment in it is orthomodular.

  12. 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.

  13. Parameter Scan for the CLIC Damping Rings

    CERN Document Server

    Papaphilippou, Y; Korostelev, M

    2008-01-01

    Triggered by the RF frequency reduction of the CLIC main linac cavities, the damping ring parameters had to be reevaluated and the rings performance adapted to the new luminosity requirements. In view of a staged approach for reaching the ultimate energy of the collider, the dependence of the rings output emittances under the influence of Intrabeam Scattering is evaluated with respect to different beam characteristics such as bunch population, beam energy, coupling and longitudinal beam characteristics.

  14. Study on the makinq of Cockroft Walton high tension

    International Nuclear Information System (INIS)

    Hutapea, Sumihar.

    1976-01-01

    A prototype of a generator is being developed at the GAMA Research Center. Experience in working with some components, high voltage capacitor, column, and potential divider is discussed. High voltage diode, the type which is usually used in television, is used. The tension of the generator is measured by using the high ohmic resistence of 4000 megaohm. The maximum tension can be reached no more than 150000 volts. (author)

  15. Nonzero Ideal Gas Contribution to the Surface Tension of Water.

    Science.gov (United States)

    Sega, Marcello; Fábián, Balázs; Jedlovszky, Pál

    2017-06-15

    Surface tension, the tendency of fluid interfaces to behave elastically and minimize their surface, is routinely calculated as the difference between the lateral and normal components of the pressure or, invoking isotropy in momentum space, of the virial tensor. Here we show that the anisotropy of the kinetic energy tensor close to a liquid-vapor interface can be responsible for a large part of its surface tension (about 15% for water, independent from temperature).

  16. Concentric and eccentric time-under-tension during strengthening exercises

    DEFF Research Database (Denmark)

    Skovdal Rathleff, Michael; Thorborg, Kristian; Bandholm, Thomas

    2013-01-01

    Total, single repetition and contraction-phase specific (concentric and eccentric) time-under-tension (TUT) are important exercise-descriptors, as they are linked to the physiological and clinical response in exercise and rehabilitation.......Total, single repetition and contraction-phase specific (concentric and eccentric) time-under-tension (TUT) are important exercise-descriptors, as they are linked to the physiological and clinical response in exercise and rehabilitation....

  17. Observer-based fault diagnosis for trucks belt tensioner

    OpenAIRE

    Dubuc , Donatien; Sename , Olivier; Bresch-Pietri , Delphine; Gauthier , Christophe

    2017-01-01

    International audience; This paper deals with the monitoring of a serpentine belt tensioner performance, a critical automotive engine component guaranteeing the cooling system efficiency. A belt tensioner fault will affect the transmission, deteriorate the water pump efficiency, and eventually, lead the engine to stall. Monitoring this component is thus a key to design predictive or corrective maintenance. In this paper, we propose to estimate a parameter which is shown to be characteristic o...

  18. Surface tension and related thermodynamic quantities of aqueous electrolyte solutions

    CERN Document Server

    Matubayasi, Norihiro

    2013-01-01

    Surface tension provides a thermodynamic avenue for analyzing systems in equilibrium and formulating phenomenological explanations for the behavior of constituent molecules in the surface region. While there are extensive experimental observations and established ideas regarding desorption of ions from the surfaces of aqueous salt solutions, a more successful discussion of the theory has recently emerged, which allows the quantitative calculation of the distribution of ions in the surface region. Surface Tension and Related Thermodynamic Quantities of Aqueous Electrolyte Solutions provides a d

  19. Queer feminist international relations: uneasy alliances, productive tensions

    OpenAIRE

    Leigh, Darcy

    2017-01-01

    This article examines the ‘uneasy alliance’ between Feminist IR and Queer IR. The article focusses on three areas of tension and continuity between the fields: (1) sexuality, sexual deviance and gender variance; (2) the roles of liberalism in gendered, sexualized and racialized violence; and (3) binaries relating to sex, gender and sexuality. The article argues that it is around tensions between Queer and Feminist IR that a Queer Feminist IR can be productively articulated. In particular, a Q...

  20. The spatial string tension and dimensional reduction in QCD

    Science.gov (United States)

    Cheng, M.; Datta, S.; van der Heide, J.; Huebner, K.; Karsch, F.; Kaczmarek, O.; Laermann, E.; Liddle, J.; Mawhinney, R. D.; Miao, C.; Petreczky, P.; Petrov, K.; Schmidt, C.; Soeldner, W.; Umeda, T.

    2008-08-01

    We calculate the spatial string tension in (2+1) flavor QCD with physical strange quark mass and almost physical light quark masses using lattices with temporal extent Nτ=4, 6 and 8. We compare our results on the spatial string tension with predictions of dimensionally reduced QCD. This suggests that also in the presence of light dynamical quarks dimensional reduction works well down to temperatures 1.5Tc.

  1. Managing Tensions Between New and Existing Business Models

    DEFF Research Database (Denmark)

    Sund, Kristian J.; Bogers, Marcel; Villarroel Fernandez, Juan Andrei

    2016-01-01

    Exploring new business models may be a good way to stay competitive, but doing so can create tensions internally, in areas such as organizational structure and competition for resources. Companies exploring business model innovation may not recognize the inevitability of these tensions and thus b...... be poorly prepared to manage them. But understanding these issues may lessen some of the organizational challenges associated with business model innovation....

  2. Development of Fabric-Type of Tensional Force Sensor

    OpenAIRE

    Suzuki, Y; Ogura, D; Shikida, M; Hasegawa, Y; Sato, K

    2009-01-01

    We developed a tensional force sensor by applying artificial tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA) hollow fibers. The fibers were fabricated by depositing thin metal and an insulation layer on the PFA tube, and the fabric sensor was made by weaving the decorated PFA tube and the conventional cotton yarns together. The sensor was 57.0 times 4.0 mm. The sensor output linearly increased with the increase of the tension. We confirmed that the sensor output increased with a...

  3. Central and peripheral mechanisms in chronic tension-type headache

    OpenAIRE

    Lipchik, Gay L.; Holroyd, Kenneth A.; France, Christopher R.; Kvaal, Steven A.; Segal, David; Cordingley, Gary E.; Rokicki, Lori A.; McCool, Heidi R.

    1996-01-01

    The second exteroceptive suppression of masseter muscle activity (ES2) and tenderness in pericranial muscles were evaluated in 112 young adults who met IHS criteria in the following diagnostic classifications: 31 chronic tension headache, 31 episodic tension headache, 33 migraine without aura and 17 migraine with aura. An additional 31 subjects served as controls. Pericranial muscle tenderness better distinguished diagnostic subgroups and better distinguished recurrent headache sufferers from...

  4. The role of muscles in tension-type headache

    DEFF Research Database (Denmark)

    Bendtsen, Lars; Fernández-de-la-Peñas, César

    2011-01-01

    The tenderness of pericranial myofascial tissues and number of myofascial trigger points are considerably increased in patients with tension-type headache (TTH). Mechanisms responsible for the increased myofascial pain sensitivity have been studied extensively. Peripheral activation or sensitizat......The tenderness of pericranial myofascial tissues and number of myofascial trigger points are considerably increased in patients with tension-type headache (TTH). Mechanisms responsible for the increased myofascial pain sensitivity have been studied extensively. Peripheral activation...

  5. MDT WIRE TENSION MEASUREMENT USING AN ELECTROSTATIC METHOD

    CERN Document Server

    Balla, A; Esposito, B; Felici, G; Nedosekin, A; Ponzio, B; Russo, V; Spitalieri, M C

    1998-01-01

    An automated system to measure wire tension in MDT tubes is presented.The method uses electrostatic forces between wire and tube to excite mechanical oscillation around the wire harmonic resonance. A LC oscillating circuit is used to measure capacitance variation due towire oscillation. Wire tension is determined by the frequency at which the wirereaches the maximum oscillation amplitude. Both the excitation and measuring circuits are controlled by a computer.

  6. 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...

  7. Forandringslæring med autismediagnoser?

    DEFF Research Database (Denmark)

    Gustafson, Kari Ingrid; Mørck, Line Lerche

    2013-01-01

    Rasmus’ ændringer i læring, selvforståelse og tilhørsforhold perspektiveres med andre ASF-diagnostiseredes læring udforsket bl.a. gennem gruppeinterviews i regi af Asperger-foreningen. Artiklen byder således på et alternativ i form af at forstå forandringslæring som overskridende læring, med langt større...... hvor fx Asperger-foreningen, lærere og skolebørns- og unges-fællesskaber, samt forældrene er vigtige aktører i overskridelsen af marginalisering....

  8. 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.

  9. 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

  10. 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

  11. Contact angle control of sessile drops on a tensioned web

    Science.gov (United States)

    Park, Janghoon; Kim, Dongguk; Lee, Changwoo

    2018-04-01

    In this study, the influence of the change of tension applied to flexible and thin web substrate on the contact angle of sessile drop in roll-to-roll system was investigated. Graphene oxide and deionized water solutions were used in the experiments. Tension was changed to 29, 49, and 69 N, and the casting distance of the micropipette and the material was set to 10, 20, and 40 mm, and the droplet volume was set to 10, 20, and 30 μL, respectively. Statistical analysis of three variables and analysis of the variance methodology showed that the casting distance was most significant for the contact angle change, and the most interesting tension variable was also affected. The change in tension caused the maximum contact angle to change by 5.5°. The tension was not uniform in the width direction. When the droplet was applied in the same direction in the width direction, it was confirmed that the tension unevenness had great influence on the contact angle up to 11°. Finally, the casting distance, which has a large effect on the contact angle, was calibrated in the width direction to reduce the width direction contact angle deviation to 1%. This study can be applied to fine patterning research using continuous inkjet printing and aerosol jet printing, which are roll-to-roll processes based on droplet handling.

  12. Tension-Enhanced Hydrogen Evolution Reaction on Vanadium Disulfide Monolayer.

    Science.gov (United States)

    Pan, Hui

    2016-12-01

    Water electrolysis is an efficient way for hydrogen production. Finding efficient, cheap, and eco-friendly electrocatalysts is essential to the development of this technology. In the work, we present a first-principles study on the effects of tension on the hydrogen evolution reaction of a novel electrocatalyst, vanadium disulfide (VS2) monolayer. Two electrocatalytic processes, individual and collective processes, are investigated. We show that the catalytic ability of VS2 monolayer at higher hydrogen coverage can be efficiently improved by escalating tension. We find that the individual process is easier to occur in a wide range of hydrogen coverage and the collective process is possible at a certain hydrogen coverage under the same tension. The best hydrogen evolution reaction with near-zero Gibbs free energy can be achieved by tuning tension. We further show that the change of catalytic activity with tension and hydrogen coverage is induced by the change of free carrier density around the Fermi level, that is, higher carrier density, better catalytic performance. It is expected that tension can be a simple way to improve the catalytic activity, leading to the design of novel electrocatalysts for efficient hydrogen production from water electrolysis.

  13. Patients with tension-type headaches feel stigmatized

    Directory of Open Access Journals (Sweden)

    Sanjay Prakash

    2016-01-01

    Full Text Available The author, a sufferer of tension-type headache (TTH, believes that the word "tension" in "tension-type headache" carries a social stigma and that patients do not accept a diagnosis of TTH readily. TTH is the most common primary headache disorder. The disability of TTH as a burden of society is greater than that of migraine. Absenteeism because of TTH is higher than that due to migraine. However, patients with TTH do not go for consultation. Even the prevalence of new daily persistent headache (NDPH is 12 times higher at the headache clinic than that of chronic TTH (CTTH. These points hint that TTH patients probably do not want to visit the clinic. The author believes that it could be because of the stigma attached to "tension." Herein, the author has noted the first responses given by 50 consecutive patients with TTH when they were told that they had been suffering from TTH. The first answer of 64% of patients with TTH was "I do not have any tension/stress ." This denial is similar to the denial declared by patients with depression. Depression and tension are similar in the sense that both are considered as a signs of personal weakness. Such a preconception in the society creates a stigma, and patients deny the diagnosis, conceal symptoms, and become reluctant to seek help and treatment.

  14. 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)

  15. Mechanical support of a ceramic gas turbine vane ring

    Science.gov (United States)

    Shi, Jun; Green, Kevin E.; Mosher, Daniel A.; Holowczak, John E.; Reinhardt, Gregory E.

    2010-07-27

    An assembly for mounting a ceramic turbine vane ring onto a turbine support casing comprises a first metal clamping ring and a second metal clamping ring. The first metal clamping ring is configured to engage with a first side of a tab member of the ceramic turbine vane ring. The second metal clamping ring is configured to engage with a second side of the tab member such that the tab member is disposed between the first and second metal clamping rings.

  16. Ring opening metathesis polymerization catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Grubbs, R.H.; Johnson, L.K.; Novak, B.M.; Hillmyer, M.; Benedicto, A.; France, M.; Nguyen, S.T. [California Institute of Technology, Pasadena, CA (United States)

    1993-12-31

    Over the past eight years, a number of new catalysts for the ring opening metathesis polymerization of cyclic olefins have been developed. These catalysts are simple organometallic complexes containing metal carbon multiple bonds that in most cases polymerize olefins by a living process. These catalysts have been used to prepare a family of near monodispersed and structurally homogeneous polymers, a series of telechelic polymers with controlled molecular weight and functionality and triblock polymers with segments with potentially interesting electronic properties. A series of new group VIII catalysts are being developed that allow a wide range of functionality to be incorporated into the polymer side chains. The same catalysts can also be used in the synthesis of fine chemicals.

  17. 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

  18. 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.

  19. What confines the rings of Saturn?

    Science.gov (United States)

    Tajeddine, Radwan; Nicholson, Philip D.; El Moutamid, Maryame; Longaretti, Pierre-Yves; Burns, Joseph A.

    2017-10-01

    The viscous spreading of planetary rings is believed to be counteracted by satellite torques, either through an individual resonance or through overlapping resonances (when the satellite is close to the ring edge). For the A ring of Saturn, it has been commonly believed that the satellite Janus alone can prevent the ring from spreading via its 7:6 Lindblad resonance. We discuss this common misconception and show that, in reality, the A ring is confined by the contributions from the group of satellites Pan, Atlas, Prometheus, Pandora, Janus, Epimetheus, and Mimas, whose resonances gradually decrease the angular momentum flux transported outward through the ring via density and bending waves. We further argue that this decrease in angular momentum flux occurs through the mechanism of ‘flux reversal’.We find that the Janus 7:6 torque is relatively feeble, as is the comparable torque of the nearby small satellite Atlas, each amounting to less than one-tenth of the angular momentum transport carried by the A ring. But the cumulative torques of the many other satellite resonances in the A ring sufficiently reduce the angular momentum flux through the rings so that the torques due to Janus and Atlas are effective in confining the outer edge of the ring.Furthermore, we use the magnitude of the satellites’ resonance torques to estimate the effective viscosity profile across the A ring, showing that it decreases from ~50 cm2 s-1 at the inner edge to less than ~11 cm2 s-1 at the outer edge. The gradual estimated decrease of the angular momentum flux and effective viscosity are roughly consistent with results obtained by balancing the shepherding torques from Pan and Daphnis with the viscous torque at the edges of the Encke and Keeler gaps, as well as the edge of the A ring.On the other hand, the Mimas 2:1 Lindblad resonance alone seems to be capable of confining the edge of the B ring, and contrary to the situation in the A ring, we show that the effective viscosity

  20. 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.

  1. 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)

  2. Perceiving the affordance of string tension for power strokes in badminton: expertise allows effective use of all string tensions.

    Science.gov (United States)

    Zhu, Qin

    2013-01-01

    Affordances mean opportunities for action. These affordances are important for sports performance and relevant to the abilities developed by skilled athletes. In racquet sports such as badminton, different players prefer widely different string tension because it is believed to provide opportunities for effective strokes. The current study examined whether badminton players can perceive the affordance of string tension for power strokes and whether the perception of affordance itself changed as a function of skill level. The results showed that string tension constrained the striking performance of both novice and recreational players, but not of expert players. When perceptual capability was assessed, perceptual mode did not affect perception of the optimal string tension. Skilled players successfully perceived the affordance of string tension, but only experts were concerned about saving energy. Our findings demonstrated that perception of the affordance of string tension in badminton was determined by action abilities. Furthermore, experts could adjust the action to maintain a superior level of performance based on the perception of affordance.

  3. Crystallographic Analysis of Fatigue Crack Initiation Behavior in Coarse-Grained Magnesium Alloy Under Tension-Tension Loading Cycles

    Science.gov (United States)

    Tamada, Kazuhiro; Kakiuchi, Toshifumi; Uematsu, Yoshihiko

    2017-07-01

    Plane bending fatigue tests are conducted to investigate fatigue crack initiation mechanisms in coarse-grained magnesium alloy, AZ31, under the stress ratios R = -1 and 0.1. The initial crystallographic structures are analyzed by an electron backscatter diffraction method. The slip or twin operation during fatigue tests is identified from the line angle analyses based on Euler angles of the grains. Under the stress ratio R = -1, relatively thick tension twin bands are formed in coarse grains. Subsequently, compression twin or secondary pyramidal slip operates within the tension twin band, resulting in the fatigue crack initiation. On the other hand, under R = 0.1 with tension-tension loading cycles, twin bands are formed on the specimen surface, but the angles of those bands do not correspond to tension twins. Misorientation analyses of c-axes in the matrix grain and twin band reveal that double twins are activated. Under R = 0.1, fatigue crack initiates along the double twin boundaries. The different manners of fatigue crack initiation at R = -1 and 0.1 are related to the asymmetricity of twining under tension and compression loadings. The fatigue strengths under different stress ratios cannot be estimated by the modified Goodman diagram due to the effect of stress ratio on crack initiation mechanisms.

  4. How bilateral iliolumbar fusion increases the stability of horizontal osteosynthesis in unstable pelvic ring injuries?

    Science.gov (United States)

    Bodzay, T; Sztrinkai, G; Gál, T; Simonovics, J; Váradi, K

    2013-07-01

    In type C pelvic ring injuries, the operative stabilization of the posterior ring is absolutely indicated. There exist four different types of operative methods: iliosacral screw fixation, transsacral plate synthesis, ventral plate fixation (primarily for sacroiliac luxations), and local plate synthesis performed on the dorsal cortex of the sacrum. In our current article, we analyzed the stability of fixation methods used together with bilateral iliolumbar techniques. We analyzed a finite element pelvic model attached to lumbar 4-5 vertebrae. By imitating a standing position on two feet, we measured the differences in tension and displacement in T1 and T2 thoracic vertebrae fractures with and without iliolumbar fusion in cases of iliosacral screw fixation, transsacral plate synthesis and KFI-H (small fragment-H) plate synthesis. The osteosynthesises reinforced via Galveston technique were rather stable; the amount of displacement measured in the fracture gap was significantly less than in the cases without iliolumbar fusion. The tension in the implants were below the allowed values, therefore they were capable of withstanding the imposed loads without permanent deformation. In unilateral pelvis injuries, if a non-weight bearing status cannot be achieved on the injured side, unilateral iliolumbar fusion reinforcement is justified, since the contralateral lower limb must also be non-weight bearing due to the pelvis injury itself. In the case of the most unstable sacrum fracture--"jumper's fracture", bilateral iliolumbar fusion is necessary, in which case the patient will be able to bear weight during the early postoperative period.

  5. The relaxant effect of curcumin on porcine coronary arterial ring segments.

    Science.gov (United States)

    Xu, Pei-Han; Long, Yuan; Dai, Fang; Liu, Zhong-Li

    2007-07-01

    Curcumin is a naturally occurring phenolic compound isolated as a yellow pigment from turmeric (curcuma longa). This compound has received much attention due to its diversity of biological and pharmacological activities. The purpose of this study was to assess the effect of curcumin on porcine coronary arteries and to investigate the mechanism of its action, if any. The isometric tension of coronary arterial rings taken from porcine hearts was measured and its response to curcumin (10(-11)-10(-5) mol/l) was studied. It was found that curcumin significantly reduced the isomeric tension of both quiescent and prostaglandin F2alpha (PGF2alpha) precontracted porcine coronary arterial rings. The relaxing effect of curcumin on coronary arteries was significantly reduced by removal of endothelium, and by the addition of N-nitro-L-arginine (L-NNA), methylene blue or propranolol, but not by indomethacin. These results suggest that curcumin-induced relaxation of isolated porcine coronary arteries might involve the action of nitric oxide (NO), cyclic guanosine monophosphate (cGMP) and adrenergic beta-receptor, but not involve the synthesis of prostaglandin.

  6. Two cases of halo scalp ring.

    Science.gov (United States)

    Douri, Thaer Hasan

    2016-11-15

    Halo scalp ring (HSR) is a rare form of non-scarring annular alopecia that is attributed to caput succedaneum. It arises perinatally because of prolonged pressure on the scalp by the cervix during or before the delivery. We report two new cases of halo scalp ring in full term pregnancy - newborns.

  7. Two cases of halo scalp ring

    OpenAIRE

    Douri, Thaer Hasan

    2016-01-01

    Halo scalp ring (HSR) is a rare form of non-scarring annular alopecia that is attributed to caput succedaneum. It arises perinatally because of prolonged pressure on the scalp by the cervix during or before the delivery. We report two new cases of halo scalp ring in full term pregnancy - newborns.

  8. Local duality for 2-dimensional local ring

    Indian Academy of Sciences (India)

    We prove a local duality for some schemes associated to a 2-dimensional complete local ring whose residue field is an -dimensional local field in the sense of Kato–Parshin. Our results generalize the Saito works in the case =0 and are applied to study the Bloch–Ogus complex for such rings in various cases.

  9. 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

  10. 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.

  11. Counteracting ring formation in rotary kilns

    NARCIS (Netherlands)

    Pisaroni, M.; Sadi, R.; Lahaye, D.

    Avoiding the formation of rings in rotary kilns is an issue of primary concern to the cement production industry. We developed a numerical combustion model that revealed that in our case study rings are typically formed in zones of maximal radiative heat transfer. This local overheating causes the

  12. 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...

  13. Familial transmission of a ring chromosome 21

    DEFF Research Database (Denmark)

    Hertz, Jens Michael

    1987-01-01

    A ring chromosome 21 was found in a phenotypically normal mother and her son. The clinical findings in the son were bilateral retention of the testes and a slightly delayed puberty onset. Consequences of a ring formation of a chromosome 21 in phenotypically normal patients are presented...

  14. Coefficient rings of formal group laws

    International Nuclear Information System (INIS)

    Buchstaber, V M; Ustinov, A V

    2015-01-01

    We describe the coefficient rings of universal formal group laws which arise in algebraic geometry, algebraic topology and their application to mathematical physics. We also describe the homomorphisms of these coefficient rings coming from reductions of one formal group law to another. The proofs are based on the number-theoretic properties of binomial coefficients. Bibliography: 37 titles

  15. Ring chromosome 13 and ambiguous genitalia.

    Science.gov (United States)

    Ozsu, Elif; Yeşiltepe Mutlu, Gül; Ipekçi, Belkıs

    2014-01-01

    Ambiguous genitalia, known to be associated with sex chromosome disorders, may also be seen with autosomal chromosome anomalies. Herein, we report a case with ambiguous genitalia and ring chromosome 13. Ring chromosome 13 is a rare genetic anomaly in which the loss of genetic material determines the clinical spectrum.

  16. Ring Chromosome 13 and Ambiguous Genitalia

    OpenAIRE

    Özsu, Elif; Yeşiltepe Mutlu, Gül; İpekçi, Belkıs

    2014-01-01

    Ambiguous genitalia, known to be associated with sex chromosome disorders, may also be seen with autosomal chromosome anomalies. Herein, we report a case with ambiguous genitalia and ring chromosome 13. Ring chromosome 13 is a rare genetic anomaly in which the loss of genetic material determines the clinical spectrum.

  17. 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 ... Author Affiliations. Li-Xin Mao1. Institute of Mathematics, Nanjing Institute of Technology, Nanjing 211167, People's Republic of China ...

  18. 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...

  19. 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.

  20. Piecewise catenarian and going between rings.

    OpenAIRE

    Brodmann, M.

    1980-01-01

    The main purpose of this paper is to prove the following theorem. Let R be a noetherian ring and n a nonnegative integer. Then R[X1, ••• ,Xn] is a going-between ring (=GB) iff R is GB and is (n+l)-piecewise catenarian.

  1. The decay of confined vortex rings

    Science.gov (United States)

    Stewart, K. C.; Niebel, C. L.; Jung, S.; Vlachos, P. P.

    2012-07-01

    Vortex rings are produced during the ejection of fluid through a nozzle or orifice, which occurs in a wide range of biological conditions such as blood flow through the valves of the heart or through arterial constrictions. Confined vortex ring dynamics, such as these, have not been previously studied despite their occurrence within the biological flow conditions mentioned. In this work, we investigate laminar vortex rings using particle image velocimetry and develop a new semi-empirical model for the evolution of vortex ring circulation subject to confinement. Here we introduce a decay parameter β which exponentially grows with increasing vortex ring confinement ratio, the ratio of the vortex ring diameter ( D VR) to the confinement diameter ( D), with the relationship β=4.38 exp(9.5D_VR/D), resulting in a corresponding increase in the rate of vortex ring circulation decay. This work enables the prediction of circulation decay rate based on confinement, which is important to understanding naturally occurring confined vortex ring dynamics.

  2. CTR related tritium research at LASL

    International Nuclear Information System (INIS)

    Anderson, J.L.; Carstens, D.H.W.; Alire, R.M.

    1975-01-01

    The solubility and diffusion coefficients of H 2 in Li contained in a cylinder of Nb/1 percent Zr were measured in the temperature range 805-905 0 C at a pressure of 575 Pa. Appropriate corrections for the solubility of H 2 in Nb/1 percent Zr were made. As expected, a finite solid cylinder diffusion model adequately delineates the time-dependent consumption of H 2 in Li. The diffusion coefficient was found to vary from 3.88 x 10 -5 to 6.92 x 10 -5 cm 2 /sec and the activation energy was estimated to be 14.7 kcal/mole. The use of low melting eutectic mixtures containing Y, La, and Ce for extracting tritium from molten lithium is being investigated. Eutectic mixtures being investigated include the 16 percent in La, 12 percent Fe in Ce and 16 percent Co in Ce. At 875 0 K the molar distribution coefficients for tritium between these eutectic mixtures and lithium are less than or equal to 100. The temperature coefficients for these distributions are also being investigated. The pressure-composition-temperature diagram for the La 5 Ni-deuterium system is being studied. A ΔH of --39.7 kcal/mole D 2 was measured for the composition D/La 1.5. (auth)

  3. 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

  4. Monlithic nonplanar ring oscillator and method

    Science.gov (United States)

    Nilsson, Alan C. (Inventor); Byer, Robert L. (Inventor)

    1991-01-01

    A monolithic nonplanar ring oscillator having an optically isotropic solid-state laser body for propagating laser radiation about a nonplanar ring path internal to the laser body is disclosed. The monolithic laser body is configured to produce a 2N reflection nonplanar ring light path, where N is an integer greater than or equal to 2, comprising 2N-1 total internal reflections and one reflection at a coupler in a single round trip. Undirectional traveling wave oscillation of the laser is induced by the geometry of the nonplanar ring path together with the effect of an applied magnetic field and partial polarizer characteristics of the oblique reflection from the coupler. The 6-reflection nonplanar ring oscillator makes possible otpimal unidirectional oscillation (low loss for the oscillating direction of propagation and, simultaneously high loss for the nonoscillating direction of propagation) in monolithic NPROs using materials with index of refraction smaller than the square root of 3, for example, laser glass.

  5. Observation of "fairy rings" in the lowlands

    Directory of Open Access Journals (Sweden)

    Barbara Sadowska

    2014-11-01

    Full Text Available Investigations on the formation of fairy rings by Agaricales were performed in the year·s 1971-1974 in forest meadows and reserves in Dziekanów Leśny and on agricultural mowed ones in Kazuń near Warsaw. During 240 observations 378 maps were made. In forest meadows 15 species formed rings and on agricultural mowed meadows 22 species. Many species formed rings considerably affecting the growth of vascular plants. This caused the formation of distinct zone.s parallel to the lines of fructifications. Many more species formed rings without affecting the growth and species composition of vascular plants. The appearance of fairy rings and the analysis of the reasons for their occurrence may facilitate in a certain sense the investigation of the speed and way of growth of mycelium in the soil.

  6. 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

  7. An evolving view of Saturn's dynamic rings.

    Science.gov (United States)

    Cuzzi, J N; Burns, J A; Charnoz, S; Clark, R N; Colwell, J E; Dones, L; Esposito, L W; Filacchione, G; French, R G; Hedman, M M; Kempf, S; Marouf, E A; Murray, C D; Nicholson, P D; Porco, C C; Schmidt, J; Showalter, M R; Spilker, L J; Spitale, J N; Srama, R; Sremcević, M; Tiscareno, M S; Weiss, J

    2010-03-19

    We review our understanding of Saturn's rings after nearly 6 years of observations by the Cassini spacecraft. Saturn's rings are composed mostly of water ice but also contain an undetermined reddish contaminant. The rings exhibit a range of structure across many spatial scales; some of this involves the interplay of the fluid nature and the self-gravity of innumerable orbiting centimeter- to meter-sized particles, and the effects of several peripheral and embedded moonlets, but much remains unexplained. A few aspects of ring structure change on time scales as short as days. It remains unclear whether the vigorous evolutionary processes to which the rings are subject imply a much younger age than that of the solar system. Processes on view at Saturn have parallels in circumstellar disks.

  8. 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.

  9. 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

  10. Exploring the tensions of being and becoming a medical educator.

    Science.gov (United States)

    Sethi, Ahsan; Ajjawi, Rola; McAleer, Sean; Schofield, Susie

    2017-03-23

    Previous studies have identified tensions medical faculty encounter in their roles but not specifically those with a qualification in medical education. It is likely that those with postgraduate qualifications may face additional tensions (i.e., internal or external conflicts or concerns) from differentiation by others, greater responsibilities and translational work against the status quo. This study explores the complex and multi-faceted tensions of educators with qualifications in medical education at various stages in their career. The data described were collected in 2013-14 as part of a larger, three-phase mixed-methods research study employing a constructivist grounded theory analytic approach to understand identity formation among medical educators. The over-arching theoretical framework for the study was Communities of Practice. Thirty-six educators who had undertaken or were undertaking a postgraduate qualification in medical education took part in semi-structured interviews. Participants expressed multiple tensions associated with both becoming and being a healthcare educator. Educational roles had to be juggled with clinical work, challenging their work-life balance. Medical education was regarded as having lower prestige, and therefore pay, than other healthcare career tracks. Medical education is a vast speciality, making it difficult as a generalist to keep up-to-date in all its areas. Interestingly, the graduates with extensive experience in education reported no fears, rather asserting that the qualification gave them job variety. This is the first detailed study exploring the tensions of educators with postgraduate qualifications in medical education. It complements and extends the findings of the previous studies by identifying tensions common as well as specific to active students and graduates. These tensions may lead to detachment, cynicism and a weak sense of identity among healthcare educators. Postgraduate programmes in medical education

  11. 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.

  12. 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.

  13. Exploratory experimental investigations on post-tensioned structural glass beams

    Directory of Open Access Journals (Sweden)

    Christian Louter

    2014-06-01

    Full Text Available Corresponding author: Dr. ir. Christian Louter, Steel Structures Laboratory (ICOM, School of Architecture, Civil and Environmental Engineering (ENAC, École Polytechnique Fédérale de Lausanne (EPFL, GC B3 505, Station 18, Lausanne CH-1015, Switzerland. Tel.: +41 21 6932427; Fax: +41 21 6932868; E-mail: christian.louter@epfl.ch The mechanical response of post-tensioned glass beams is explored in this paper. This is done through bending experiments on post-tensioned glass beam specimens with either mechanically anchored or adhesively bonded steel tendons by which a beneficial pre-stress is inflicted on the glass beams. In addition, reference beams with identical geometry but without tendons are tested. From the results of the bending experiments it can be seen that the post-tensioned glass beams reach higher initial fracture loads than the reference glass beams. Furthermore, the post-tensioned glass beams develop a significant post-fracture reserve. From this it is concluded that post-tensioning a glass beam is a feasible concept, which provides increased initial fracture strength and enhanced post-fracture performance.

  14. Hyperautofluorescent ring in eyes with macular holes

    Directory of Open Access Journals (Sweden)

    Sato T

    2013-08-01

    Full Text Available Tatsuhiko Sato, Kazuyuki Emi, Yui Osawa, Hajime Bando Osaka Rosai Hospital Clinical Research Center for Occupational Sensory Organ Disability, Sakai, Japan Background: Fundus autofluorescence studies in eyes with macular holes (MHs have shown a hyperautofluorescent spot corresponding to the hole and a hypoautofluorescent ring corresponding to the fluid cuff surrounding the hole. The purpose of this report is to present three cases of MH with a different fundus autofluorescence pattern. Case reports: Case 1 was a 62-year-old woman who did not know the duration of the MH in her left eye. Her decimal best-corrected visual acuity (BCVA was 0.08. The left eye had a one-half disc diameter MH with a depigmented ring surrounding the area of the fluid cuff. Fundus autofluorescence showed a hyperautofluorescent ring corresponding to the depigmented ring. After vitrectomy, fundus autofluorescence showed the same size hyperautofluorescent ring despite the decreased size of the opened MH. Case 2 was a 69-year-old woman who had been diagnosed with MH in the right eye 13 years earlier. Her decimal BCVA was 0.1. The right eye had a one-half disc diameter MH with a depigmented ring surrounding the area of the fluid cuff. Fundus autofluorescence showed a hyperautofluorescent ring corresponding to the depigmented ring. Postoperative fundus autofluorescence showed the same size hyperautofluorescent ring despite the hole being closed. The decimal BCVA was 0.2 in her right eye 6 months after vitrectomy. Case 3 was a 71-year-old woman who had been diagnosed with MH in the right eye 15 years earlier. Her decimal BCVA was 0.1. The right eye had a one-half disc diameter MH with a depigmented ring which corresponded with a hyperautofluorescent ring. Postoperative fundus autofluorescence showed the same size hyperautofluorescent ring despite the hole being closed. The decimal BCVA was 0.2 in her right eye 6 months after vitrectomy. Conclusion: Our findings suggest that a

  15. Wedding ring shaped excitation coil

    Science.gov (United States)

    MacLennan, Donald A.; Tsai, Peter

    2001-01-01

    A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency.

  16. Surface tension in microsystems engineering below the capillary length

    CERN Document Server

    Lambert, Pierre

    2014-01-01

    This book describes how surface tension effects can be used by engineers to provide mechanical functions in miniaturized products (<1 mm). Even if precursors of this field such as Jurin or Laplace already date back to the 18th century, describing surface tension effects from a mechanical perspective is very recent. The originality of this book is to consider the effects of capillary bridges on solids, including forces and torques exerted both statically and dynamically by the liquid along the 6 degrees-of-freedom. It provides a comprehensive approach to various applications, such as capillary adhesion (axial force), centering force in packaging and micro-assembly (lateral force) and recent developments such as a capillary motor (torque). It devises how surface tension can be used to provide mechanical functions such as actuation (bubble-actuated compliant table), sealing and tightness, energy harvesting, nanodispending.

  17. Dissipative Particle Dynamics of tension-induced membrane fusion

    DEFF Research Database (Denmark)

    Shillcock, Julian C.

    2009-01-01

    Recent studies of tension-induced membrane fusion using dissipative particle dynamics (DPD) simulations are briefly reviewed. The stochastic nature of the fusion process makes it necessary to simulate a large number of fusion attempts in order to obtain reliable fusion statistics and to extract...... meaningful values for the fusion probability and the average fusion times. All successful fusion events follow the same pathway. In this fusion pathway, configurations of individual lipids play an important role. Fusion starts with individual lipids assuming a splayed tail configuration with one tail......, three sub-processes have been identified in the fusion pathway. Their energy barriers are estimated to lie in the range 8-15kBT. The fusion probability is found to possess a maximum at intermediate tension values. As one decreases the tension, the fusion probability seems to vanish before...

  18. Tension Pneumatocele due to Enterobacter gergoviae Pneumonia: A Case Report

    Directory of Open Access Journals (Sweden)

    Emeka B. Kesieme

    2012-01-01

    Full Text Available Pneumatocele formation is a known complication of pneumonia. Very rarely, they may increase markedly in size, causing cardiorespiratory compromise. Many organisms have been implicated in the pathogenesis of this disease; however, this is the first report of tension pneumatocele resulting from Enterobacter gergoviae pneumonia. We report a case of a 3-month-old Nigerian male child who developed two massive tension pneumatoceles while on treatment for postpneumonic empyema due to Enterobacter gergoviae pneumonia. Tube thoracostomy directed into both pneumatocele resulted in complete resolution and recovery. Enterobacter gergoviae is a relevant human pathogen, capable of causing complicated pneumonia with fatal outcome if not properly managed. In developing countries where state-of the-art radiological facilities and expertise for prompt thoracic intervention are lacking, there is still room for nonoperative management of tension pneumatocele especially in very ill children.

  19. A Kolsky tension bar technique using a hollow incident tube

    Science.gov (United States)

    Guzman, O.; Frew, D. J.; Chen, W.

    2011-04-01

    Load control of the incident pulse profiles in compression Kolsky bar experiments has been widely used to subject the specimen to optimal testing conditions. Tension Kolsky bars have been used to determine dynamic material behavior since the 1960s with limited capability to shape the loading pulses due to the pulse-generating mechanisms. We developed a modified Kolsky tension bar where a hollow incident tube is used to carry the incident stress waves. The incident tube also acts as a gas gun barrel that houses the striker for impact. The main advantage of this new design is that the striker impacts on an impact cap of the incident tube. Compression pulse shapers can be attached to the impact cap, thus fully utilizing the predictive compression pulse-shaping capability in tension experiments. Using this new testing technique, the dynamic tensile material behavior for Al 6061-T6511 and TRIP 800 (transformation-induced plasticity) steel has been obtained.

  20. A Kolsky tension bar technique using a hollow incident tube

    International Nuclear Information System (INIS)

    Guzman, O; Frew, D J; Chen, W

    2011-01-01

    Load control of the incident pulse profiles in compression Kolsky bar experiments has been widely used to subject the specimen to optimal testing conditions. Tension Kolsky bars have been used to determine dynamic material behavior since the 1960s with limited capability to shape the loading pulses due to the pulse-generating mechanisms. We developed a modified Kolsky tension bar where a hollow incident tube is used to carry the incident stress waves. The incident tube also acts as a gas gun barrel that houses the striker for impact. The main advantage of this new design is that the striker impacts on an impact cap of the incident tube. Compression pulse shapers can be attached to the impact cap, thus fully utilizing the predictive compression pulse-shaping capability in tension experiments. Using this new testing technique, the dynamic tensile material behavior for Al 6061-T6511 and TRIP 800 (transformation-induced plasticity) steel has been obtained

  1. Tensile behavior and tension stiffening of reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    Choun, Young Sun; Seo, Jeong Moon

    2001-03-01

    For the ultimate behavior analysis of containment buildings under severe accident conditions, a clear understanding of tensile behaviors of plain and reinforced concrete is necessary. Nonlinear models for tensile behaviors of concrete are also needed. This report describe following items: tensile behaviors of plain concrete, test results of reinforced concrete panels in uniaxial and biaxial tension, tension stiffening. The tensile behaviors of reinforced concrete are significantly influenced by the properties of concrete and reinforcing steel. Thus, for a more reliable evaluation of tensile behavior and ultimate pressure capacity of a reinforced or prestressed concrete containment building, an advanced concrete model which can be considered rebar-concrete interaction effects should be developed. In additions, a crack behavior analysis method and tension stiffening models, which are based on fracture mechanics, should be developed. The model should be based on the various test data from specimens considering material and sectional properties of the containment building.

  2. Sun pipeline`s tensioned cover system saves storage costs

    Energy Technology Data Exchange (ETDEWEB)

    Blaisdell, J.R. [Sun Pipe Line Co., Detroit, MI (United States); Lydick, L. [National Seal Co., Aurora, IL (United States)

    1996-02-01

    Sun Pipe Line chose the Columbia tensioned floating cover (TFC) system from Columbia Geosystems for several reasons. First, capital costs for the TFC system are considerably lower than those for structural metal or concrete systems. Installation requires less time than fixed structures, and construction costs are about one-tenth as much. A second reason for the choice is its patented tower/tension cover design which easily accommodates fluctuating fluid levels in brine ponds, even in a rapid drawdown. When brine is pumped into the storage chambers, changes in brine ponds can be as great as ten feet. The tensioned design maintains folds of extra material on the outer perimeter of the cover above fluid level. As fluid levels fall, the curtain unfolds and adequate reservoir coverage is maintained.

  3. Uniaxial Tension Test of Slender Reinforced Early Age Concrete Members

    Directory of Open Access Journals (Sweden)

    Wenbo Zhang

    2011-08-01

    Full Text Available The present study aims to obtain the tensile properties of early age concrete based on a uniaxial tension test employing RC slender members. First, the paper shows that concrete strain is equal to the strain of rebar at the mid-span of the RC member. The tensile Young’s modulus and the strain capacity of early age concrete are estimated using strain measurements. The experiment indicated that the tensile Young’s modulus at an early age is higher than the compressive modulus. This observation was similar to one found in a previous investigation which used a direct tension test of early age concrete. Moreover, the paper describes how an empirical equation for mature concrete can be applied to the relation between uniaxial tensile strength and splitting tensile strength even in early age concrete. Based on a uniaxial tension test, the paper proposes an empirical equation for the relationship between standard bond stresses and relative slip.

  4. Surface tension and contact angles of molten cadmium telluride

    Science.gov (United States)

    Balasubramanian, R.; Wilcox, W. R.

    1990-01-01

    The surface tension and contact angle of molten cadmium telluride (CdTe) were measured as a function of temperature by the sessile drop technique. A FORTRAN code was developed to calculate the surface tension of sessile drops, with the contact angle ranging from O to 180°. The wetting of cadmium telluride melt was studied on different surfaces. The surface tension of cadmium telluride was about 160 ±5 dynes · cm-1[1.6 m-1] at the melting point of 1093°C. The contact angle of CdTe melt was about 65° on a quartz optical flat, 75° on commercial fused quartz, and 125° on boron nitride coated quartz.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Ring enhancement in contrast enhancement computed tomography

    International Nuclear Information System (INIS)

    Inatsuki, Shinichi; Hayashi, Kuniaki; Miyake, Hidetoshi

    1979-01-01

    Ring enhancement was examined in 11 lesions, 61 patients, we experienced. The frequency of ring enhancement observed in cerebral abscesses and tumors and the characteristics and the differential points of each disease were obtained. The frequency of ring enhancement was 54% in metastatic cerebral tumor, 56% in glioblastoma and astrocytoma (grade III) and 100% in cerebral abscess. Glioblastoma and astrocytoma (grade III) differed from other diseases in having distorted rings with poor uniform thickness. Although there was a great similarity between the computed tomographic picture of metastatic cerebral tumor and that of cerebral abscess, the ring in cerebral abscess was clearer, thin and uniform, and the peripheral edema in cerebral abscess was weak in general. In cerebral infarct, peripheral edema and mass effect of the ring were not observed or slightly observed, if any. Considering only the characteristics of the rings, there are differences between each diseases, and differentiation seems to be possibly performed. In practice, however, it is not necessarily easy to make a differential diagnosis. Clinical results should be carefully managed. (Kumagai, M.)

  10. Dynamics of the Uranian Gamma Ring

    Science.gov (United States)

    Hamilton, Douglas P.; Rimlinger, Thomas; Hahn, Joseph M.

    2017-10-01

    The planet Uranus is surrounded by a unique ring system consisting of ten narrow ringlets as well as several broad sheets of dust. The brightest of these rings is bracketed by a pair of satellites, Cordelia and Ophelia, that may serve to help confine the ring radially. Searches for smaller satellites near the other narrow rings, however, have been unsuccessful. Hamilton et. al. 2016 and Rimlinger et al. 2016 have argued that the eccentric and/or inclined uranian ringlets self confine radially by a combination of ringlet gravity and viscous forces. Importantly, no shepherd satellites are required in this model.We apply these ideas to the uranian gamma ring, a particularly strange ringlet which has, in addition to the standard elliptical shape, a superposed m=0 breathing mode (French et. al. 1988). In a pure m=0 mode, the particles in an elliptical ring all reach pericenter at the same times giving the ring a circular appearance. The particles remain synced in phase and all move outward reaching apocenter simultaneously. Thus the ring appears circular at any given time, but the radius of the circle seems to increase and decrease - it breathes. We investigate first the dynamics of the pure m=0 mode and show that the equilibrium is stable against small perturbations. We are currently moving toward a more sophisticated stability analysis for the real gamma ring with its unusual combination of normal modes. We will detail our results to date and will report on our progress toward an origin scenario for this obscure but interesting ringlet.

  11. Contact Angles and Surface Tension of Germanium-Silicon Melts

    Science.gov (United States)

    Croell, A.; Kaiser, N.; Cobb, S.; Szofran, F. R.; Volz, M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Precise knowledge of material parameters is more and more important for improving crystal growth processes. Two important parameters are the contact (wetting) angle and the surface tension, determining meniscus shapes and surface-tension driven flows in a variety of methods (Czochralski, EFG, floating-zone, detached Bridgman growth). The sessile drop technique allows the measurement of both parameters simultaneously and has been used to measure the contact angles and the surface tension of Ge(1-x)Si(x) (0 less than or equal to x less than or equal to 1.3) alloys on various substrate materials. Fused quartz, Sapphire, glassy carbon, graphite, SiC, carbon-based aerogel, pyrolytic boron nitride (pBN), AIN, Si3N4, and polycrystalline CVD diamond were used as substrate materials. In addition, the effect of different cleaning procedures and surface treatments on the wetting behavior were investigated. Measurements were performed both under dynamic vacuum and gas atmospheres (argon or forming gas), with temperatures up to 1100 C. In some experiments, the sample was processed for longer times, up to a week, to investigate any changes of the contact angle and/or surface tension due to slow reactions with the substrate. For pure Ge, stable contact angles were found for carbon-based substrates and for pBN, for Ge(1-x)Si(x) only for pBN. The highest wetting angles were found for pBN substrates with angles around 170deg. For the surface tension of Ge, the most reliable values resulted in gamma(T) = (591- 0.077 (T-T(sub m)) 10(exp -3)N/m. The temperature dependence of the surface tension showed similar values for Ge(1-x)Si(x), around -0.08 x 10(exp -3)N/m K, and a compositional dependence of 2.2 x 10(exp -3)N/m at%Si.

  12. Migration of Star Clusters and Nuclear Rings

    OpenAIRE

    van de Ven, Glenn; Chang, Philip

    2008-01-01

    Star clusters that form in nuclear rings appear to be at slightly larger radii than the gas. We argue that the star clusters move out from the gas in which they are formed because of satellite-disk tidal interactions. In calculating the dynamics of this star cluster and gas ring system, we include the effects of dynamical friction of the background stars in the host galaxy on the star cluster, and inflowing gas along the bar onto the nuclear ring at the two contact points. We show that the fi...

  13. 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.

  14. Wind turbine ring/shroud drive system

    Science.gov (United States)

    Blakemore, Ralph W.

    2005-10-04

    A wind turbine capable of driving multiple electric generators having a ring or shroud structure for reducing blade root bending moments, hub loads, blade fastener loads and pitch bearing loads. The shroud may further incorporate a ring gear for driving an electric generator. In one embodiment, the electric generator may be cantilevered from the nacelle such that the gear on the generator drive shaft is contacted by the ring gear of the shroud. The shroud also provides protection for the gearing and aids in preventing gear lubricant contamination.

  15. 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

  16. Phenylephrine Decreases Vascular Tension in Goat Arteries in Specific Circumstances.

    Directory of Open Access Journals (Sweden)

    Renu R Raj

    Full Text Available Phenylephrine (PE causes vasoconstriction through alpha adrenergic receptors. PE-induced vasodilatation has also been reported earlier in pre-constricted vessels. Here we demonstrate in spiral strips of goat arteries that addition of PE can decrease tone even from base-line levels (i.e. not pre-constricted and show that this process requires nitric oxide (NO and alpha adrenergic stimulation, but is cGMP-independent. Under control conditions, PE caused vasoconstriction, but under conditions where NO levels are higher, as with L-Arginine or sodium nitroprusside, PE decreased vessel tension. L-Arginine/PE combination was not able to decrease tension when alpha adrenoceptors were blocked with Phentolamine or endothelial nitric oxide synthase (eNOS was blocked with Nω-Nitro-L-arginine (L-NNA. Propranolol, a beta blocker, was unable to prevent the reduction in tension by the L-Arginine/PE combination. Adrenaline and noradrenaline (and not isoproterenol also reduced vessel tension in the presence of L-Arginine. Even when NO levels were not enhanced, relieving NO from having to stimulate the enzyme soluble guanylyl cyclase (sGC (either by using sGC blockers, namely ODQ or methylene blue, or by enhancing cGMP levels (with sildenafil which by negative feedback probably inhibits sGC led to PE-induced reduction of vascular tension. PMA-phorbol myristate acetate-an agonist which stimulates Protein Kinase C was able to prevent the ability of PE to reduce vascular tension in a high NO environment. Our conclusion is that PE reduces vascular tension through alpha adrenoceptors if there is excess NO availability to activate a putative pathway. Though the reduction of vessel tone by PE is dependent on NO, it is independent of cGMP. Prior treatment with PMA or PE itself can prevent further PE-induced reduction of tension in a high NO environment. The results here suggest, counter-intuitively, that alpha blockers may be of help in the treatment of septic shock

  17. Drag force on heavy quarks and spatial string tension

    Science.gov (United States)

    Andreev, Oleg

    2018-02-01

    Heavy quark transport coefficients in a strongly coupled Quark-Gluon Plasma can be evaluated using a gauge/string duality and lattice QCD. Via this duality, one can argue that for low momenta the drag coefficient for heavy quarks is proportional to the spatial string tension. Such a tension is well-studied on the lattice that allows one to straightforwardly make non-perturbative estimates of the heavy quark diffusion coefficients near the critical point. The obtained results are consistent with those in the literature.

  18. Surface tension alteration on calcite, induced by ion substitution

    DEFF Research Database (Denmark)

    Sakuma, Hiroshi; Andersson, Martin Peter; Bechgaard, Klaus

    2014-01-01

    The interaction of water and organic molecules with mineral surfaces controls many processes in nature and industry. The thermodynamic property, surface tension, is usually determined from the contact angle between phases, but how does one understand the concept of surface tension at the nanoscale...... preferentially as ion pairs at solution-calcite interfaces. Mg2+ incorporation weakens organic molecule adhesion while strengthening water adsorption so Mg2+ substitution renders calcite more water wet. When Mg2+ replaces 10% of surface Ca2+, the contact angle changes dramatically, by 40 to 70, converting...

  19. Surface tension in plasmas related to double layer formation

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, Sebastian; Lozneanu, Erzilia [Al. I. Cuza University, Dept. of Plasma Physics, Iasi (Romania)

    2001-07-01

    Self-organized space charge configurations bordered by electric double layers appear in plasma as the result of the transition into a state characterized by local minimum of the free energy. Considering the self-assemblage process of such a complex well-confined space-charge configuration in plasma, known by the name of ball of fire, as a nucleation process, it becomes possible to define an equivalent surface tension for the double layer that covers the core of the ball of fire and to make some predictions for its surface tension coefficient and capacitance. (author)

  20. Surface tension mediated conversion of light to work

    Science.gov (United States)

    Okawa, David; Pastine, Stefan J; Zettl, Alexander K; Frechet, Jean M. J

    2014-12-02

    Disclosed are a method and apparatus for converting light energy to mechanical energy by modification of surface tension on a supporting fluid. The apparatus comprises an object which may be formed as a composite object comprising a support matrix and a highly light absorptive material. The support matrix may comprise a silicon polymer. The highly light absorptive material may comprise vertically aligned carbon nanotubes (VANTs) embedded in the support matrix. The composite object is supported on a fluid. By exposing the highly light absorptive material to light, heat is generated, which changes the surface tension of the composite object, causing it to move physically within the fluid.