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Sample records for axial spondyloarthritis treated

  1. Diagnosis of spondyloarthritis of the axial skeleton

    International Nuclear Information System (INIS)

    Conventional radiography is used as the first-line imaging test in evaluating the axial skeleton for manifestations of spondyloarthritis, which is a cover term for five entities: ankylosing spondylitis, psoriatric spondyloarthritis, reactive arthritis, enteropathic arthritis, and undifferentiated spondyloarthritis. However, as it often takes many years from the onset of clinical symptoms and the first appearance of radiographic changes, a cross-sectional imaging is warranted (CT and/or MRI) for early diagnosis. MRI sensitively detects early inflammatory stages of spondyloarthritis and can thus fill the gap by markedly reducing the interval between initial symptoms and diagnosis. The aim of this article is to show that all manifestations and forms of spondyloarthritis share the same pathogenetic inflammatory pattern, namely a mixture of bone destruction and bone proliferation: enthesis - enthesitis - enthesiophyte. An enthesis in the true sense is a fibrocartilaginous junction (uncalcified fibrocartilage - tidemark - calcified fibrocartilage) between a tendon, ligament, joint capsule, or fascia and bone. The sacroiliac joint is a special form, a so-called articular fibrocartilaginous enthesis. A wide range of images - including radiographs, CT scans, and MR images - will be presented to provide a comprehensive picture of the entheseal manifestations and inflammatory patterns of the sacroiliac joints, vertebral endplates and ridges, facet joints, costovertebral junctions, and spinal ligaments in spondyloarthritis. (orig.)

  2. The window of opportunity: a relevant concept for axial spondyloarthritis

    OpenAIRE

    Robinson, Philip C.; Brown, Matthew A.

    2014-01-01

    The window of opportunity is a concept critical to rheumatoid arthritis treatment. Early treatment changes the outcome of rheumatoid arthritis treatment, in that response rates are higher with earlier disease-modifying anti-rheumatic drug treatment and damage is substantially reduced. Axial spondyloarthritis is an inflammatory axial disease encompassing both nonradiographic axial spondyloarthritis and established ankylosing spondylitis. In axial spondyloarthritis, studies of magnetic resonanc...

  3. Defining active sacroiliitis on MRI for classification of axial spondyloarthritis

    DEFF Research Database (Denmark)

    Lambert, Robert G W; Bakker, Pauline A C; van der Heijde, Désirée;

    2016-01-01

    OBJECTIVES: To review and update the existing definition of a positive MRI for classification of axial spondyloarthritis (SpA). METHODS: The Assessment in SpondyloArthritis International Society (ASAS) MRI working group conducted a consensus exercise to review the definition of a positive MRI for...

  4. An update on biomarkers in axial spondyloarthritis.

    Science.gov (United States)

    Prajzlerová, Klára; Grobelná, Kristýna; Pavelka, Karel; Šenolt, Ladislav; Filková, Mária

    2016-06-01

    Axial spondyloarthritis is a chronic inflammatory disease with the onset at a young age, and, if undiagnosed and untreated, it may result in permanent damage and lifelong disability. Rates of early diagnosis have improved, due in particular to the addition of magnetic resonance imaging into the diagnostic armamentaria; however, it is costly, not widely available, and requires experienced readers to interpret the findings. In addition to clinical measures and imaging techniques, biomarkers that will be described in this review may represent useful tools for diagnosis, monitoring disease activity and outcomes as well as therapeutic responses. Currently, HLA-B27 remains the best genetic biomarker for making a diagnosis, while CRP currently appears to be the best circulating measure for assessing disease activity, predicting structural progression and therapeutic response. Interestingly, key molecules in the pathogenesis of the disease and essential therapeutic targets, such as tumour necrosis factor (TNF)α, interleukin (IL)-17 and IL-23, show only limited association with disease characteristics or disease progression. Some genetic biomarkers and particularly anti-CD74 antibodies, may become a promising tool for the early diagnosis of axSpA. Further biomarkers, such as matrix metalloproteinases (MMP)-3, calprotectin (S100A8/9), vascular endothelial growth factor (VEGF), C-terminal telopeptide of type II collagen (CTX-II) or dickkopf-1 (DKK-1), are not sufficient to reflect disease activity, but may predict spinal structural progression. In addition, recent data have shown that monitoring calprotectin might represent a valuable biomarker of therapeutic response. However, all of these results need to be confirmed in large cohort studies prior to use in daily clinical practice. PMID:26851549

  5. Treatment with tumor necrosis factor inhibitors in axial spondyloarthritis

    DEFF Research Database (Denmark)

    Ciurea, A.; Weber, U.; Stekhoven, D.;

    2015-01-01

    -TNF agents in private practices in comparison to academic centers, adherence to ASAS treatment recommendations for TNF inhibition was equally high, and similar response rates to TNF blockers were achieved in both clinical settings. (First Release Nov 1 2014; J Rheumatol 2015; 42:101-5; doi 10.3899/jrheum......Objective. To evaluate the initiation of and response to tumor necrosis factor (TNF) inhibitors for axial spondyloarthritis (axSpA) in private rheumatology practices versus academic centers. The Journal of Rheumatology, Methods.We compared newly initiated TNF inhibition for axSpA in 363 patients...... enrolled in private practices with 100 patients recruited in 6 university hospitals within the Swiss Clinical Quality Management (SCQM) cohort., Results. All patients had been treated with > 1 nonsteroidal antiinflammatory drug and > 70% of patients had a baseline Bath Ankylosing Spondylitis Disease...

  6. Etanercept for the treatment of non-radiographic axial spondyloarthritis.

    Science.gov (United States)

    Rios Rodriguez, Valeria; Poddubnyy, Denis

    2016-05-01

    Presently, tumor necrosis factor α antagonist therapy is the only effective alternative treatment to nonsteroidal anti-inflammatory drugs for the entire spectrum of axial spondyloarthritis, including non-radiographic and radiographic (=ankylosing spondylitis) forms. Recently, etanercept has been approved by the European Medicines Agency for the treatment of non-radiographic axial spondyloarthritis, increasing the number of available treatment options for this indication. The latest data on etanercept concerning clinical efficacy and safety in short-term and long-term treatment of patients with non-radiographic axial spondyloarthritis who do not respond to the first-line therapy with non-steroidal anti-inflammatory drugs suggests good efficacy and safety profiles similar to that observed previously in ankylosing spondylitis. This article reviews recent data on the efficacy and safety of etanercept and is focused on the treatment of non-radiographic axial spondyloarthritis. This article will also discuss the role of etanercept in the context of current and developing treatment options. PMID:26788837

  7. ASAS classification criteria for axial spondyloarthritis: time to modify.

    Science.gov (United States)

    Akkoc, Nurullah; Khan, Muhammad A

    2016-06-01

    The relationship between ankylosing spondylitis and the recently proposed entity called axial spondyloarthritis with its radiographic and non-radiographic forms that have been defined by the Assessment of Spondyloarthritis International Society (ASAS) criteria for axial spondyloarthritis (axSpA), is currently being debated. The Food and Drug Agency (FDA) had criticized the ASAS criteria and the studies which used these criteria to enroll patients in a clinical trial of certolizumab and adalimumab for the treatment of non-radiographic axial spondyloarthritis. The primary aim of classification criteria is to create homogenous patient populations for basic and clinical research. But the multi-arm construct of the ASAS criteria is a potential source of heterogeneity reducing their utility. Criteria sets should be regarded as dynamic concepts open to modifications or updates as our knowledge advances. We provide evidence to conclude that it is time to modify the ASAS Criteria for axSpA, and we propose some of the steps that can be taken to start moving forward in improving the validity of these criteria. PMID:27094940

  8. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II)

    DEFF Research Database (Denmark)

    Rudwaleit, M; van der Heijde, D; Landewé, R;

    2009-01-01

    or by magnetic resonance imaging (MRI) plus at least one SpA feature ("imaging arm") or the presence of HLA-B27 plus at least two SpA features ("clinical arm"). The sensitivity and specificity of the entire set of the new criteria were 82.9% and 84.4%, and for the imaging arm alone 66.2% and 97......OBJECTIVE: To validate and refine two sets of candidate criteria for the classification/diagnosis of axial spondyloarthritis (SpA). METHODS: All Assessment of SpondyloArthritis international Society (ASAS) members were invited to include consecutively new patients with chronic (> or =3 months) back...

  9. Bone mineral density in patients with early axial spondyloarthritis

    Directory of Open Access Journals (Sweden)

    E. E. Gubar

    2015-01-01

    Full Text Available Objective: to study bone mineral density (BMD of the lumbar spine (LS and femoral neck (FN in patients with early axial spondyloarthritis (SpA and to reveal its association with inflammatory disease activity.Subjects and methods. Seventy-three patients aged 18–45 years with inflammatory back pain lasting at least 3 months and not more than 5 years were examined. Axial SpA was diagnosed according to the 2009 ASAS criteria. BASDAI and ASDAS C-reactive protein (CRP values were used to estimate disease activity; BASFI was employed to evaluate functional status. The examination encompassed determination of HLA-B27, X-ray of the pelvis and LS, magnetic resonance imaging (MRI of sacroiliac joints, LS, and hip joints (in the presence of clinical signs of their injuries, densitometry of LS (LI-IV and FN. By taking into account the young age of patients, the Z-score was applied to measure BMD. The latter is considered lower if the Z-score is 1–2 standard deviations (SD in at least one of the segments under study.Results. The median Z-score was -0.7 (-1.3; -0.3 SD for FN and 0.9 (-1.6; -0.5 SD for LS. Reduced BMD in at least one of the segments under study was detected in 13 (17.8% patients: that in LS and FN in 11 (15.1% and 5 (6.8% patients, respectively. Lower BMD was observed in two segments in 3 (4.1% patients. No association was found between lower BMD and age, gender, disease activity (BASDAI, ASDAS, and laboratory inflammatory markers (erythrocyte sedimentation rate (ESR and CRP. A relationship was established between inflammatory changes according to the data of MRI of LS (MRI spondylitis and reduced BMD in the same segment. MRI spondylitis was detected in 8 patients. Five and 3 patients with spondylitis of LS were found to have lower and normal BMD in this segment, respectively. Six out of 65 patients without MRI spondylitis in LS had its reduced BMD and the remaining (n=59 patients had its normal BMD (p=0.0014.Conclusion. There was an

  10. ASDAS, BASDAI and different treatment responses and their relation to biomarkers of inflammation, cartilage and bone turnover in patients with axial spondyloarthritis treated with TNF{alpha} inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Sørensen, Inge Juul; Garnero, Patrick;

    2011-01-01

    To investigate the relation between ankylosing spondylitis disease activity score (ASDAS), Bath ankylosing spondylitis disease activity index (BASDAI) and treatment response and biomarkers of inflammation (C-reactive protein (CRP), interleukin-6 (IL-6), YKL-40), angiogenesis (vascular endothelial...... growth factor (VEGF)), cartilage (C-terminal crosslinking telopeptide of type II collagen (CTX-II), matrix metalloproteinase-3 (MMP-3), total aggrecan, cartilage oligomeric matrix protein) and bone (C-terminal crosslinking telopeptide of type I collagen, osteocalcin) turnover in 60 patients with axial...

  11. ASDAS, BASDAI and different treatment responses and their relation to biomarkers of inflammation, cartilage and bone turnover in patients with axial spondyloarthritis treated with TNFα inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Sørensen, Inge Juul; Garnero, Patrick;

    2011-01-01

    To investigate the relation between ankylosing spondylitis disease activity score (ASDAS), Bath ankylosing spondylitis disease activity index (BASDAI) and treatment response and biomarkers of inflammation (C-reactive protein (CRP), interleukin-6 (IL-6), YKL-40), angiogenesis (vascular endothelial...... growth factor (VEGF)), cartilage (C-terminal crosslinking telopeptide of type II collagen (CTX-II), matrix metalloproteinase-3 (MMP-3), total aggrecan, cartilage oligomeric matrix protein) and bone (C-terminal crosslinking telopeptide of type I collagen, osteocalcin) turnover in 60 patients with axial...

  12. Diagnosis of spondyloarthritis of the axial skeleton; Diagnostik der Spondyloarthritiden am Achsenskelett

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, Kay-Geert A. [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie; Bollow, Matthias [Augusta-Kranken-Anstalt Bochum (Germany); Bochum Univ. (Germany)

    2009-09-15

    Conventional radiography is used as the first-line imaging test in evaluating the axial skeleton for manifestations of spondyloarthritis, which is a cover term for five entities: ankylosing spondylitis, psoriatric spondyloarthritis, reactive arthritis, enteropathic arthritis, and undifferentiated spondyloarthritis. However, as it often takes many years from the onset of clinical symptoms and the first appearance of radiographic changes, a cross-sectional imaging is warranted (CT and/or MRI) for early diagnosis. MRI sensitively detects early inflammatory stages of spondyloarthritis and can thus fill the gap by markedly reducing the interval between initial symptoms and diagnosis. The aim of this article is to show that all manifestations and forms of spondyloarthritis share the same pathogenetic inflammatory pattern, namely a mixture of bone destruction and bone proliferation: enthesis - enthesitis - enthesiophyte. An enthesis in the true sense is a fibrocartilaginous junction (uncalcified fibrocartilage - tidemark - calcified fibrocartilage) between a tendon, ligament, joint capsule, or fascia and bone. The sacroiliac joint is a special form, a so-called articular fibrocartilaginous enthesis. A wide range of images - including radiographs, CT scans, and MR images - will be presented to provide a comprehensive picture of the entheseal manifestations and inflammatory patterns of the sacroiliac joints, vertebral endplates and ridges, facet joints, costovertebral junctions, and spinal ligaments in spondyloarthritis. (orig.)

  13. Descriptions of spinal MRI lesions and definition of a positive MRI of the spine in axial spondyloarthritis

    DEFF Research Database (Denmark)

    Hermann, Kay-Geert A; Baraliakos, Xenofon; van der Heijde, Désirée M F M;

    2012-01-01

    The aim of this study was to define characteristic MRI findings in the spine of patients with axial spondyloarthritis (SpA) and provide a definition of a positive spinal MRI for inflammation and structural changes.......The aim of this study was to define characteristic MRI findings in the spine of patients with axial spondyloarthritis (SpA) and provide a definition of a positive spinal MRI for inflammation and structural changes....

  14. Fat infiltration on magnetic resonance imaging of the sacroiliac joints has limited diagnostic utility in nonradiographic axial spondyloarthritis

    DEFF Research Database (Denmark)

    Weber, Ulrich; Pedersen, Susanne J; Zubler, Veronika; Rufibach, Kaspar; Chan, Stanley M; Lambert, Robert G W; Østergaard, Mikkel; Maksymowych, Walter P

    2014-01-01

    To explore whether morphological features of fat infiltration (FI) on sacroiliac joint (SIJ) magnetic resonance imaging (MRI) contribute to diagnostic utility in 2 inception cohorts of patients with nonradiographic axial spondyloarthritis (nr-axSpA).......To explore whether morphological features of fat infiltration (FI) on sacroiliac joint (SIJ) magnetic resonance imaging (MRI) contribute to diagnostic utility in 2 inception cohorts of patients with nonradiographic axial spondyloarthritis (nr-axSpA)....

  15. Responsiveness of the Ankylosing Spondylitis Disease Activity Score (ASDAS) and clinical and MRI measures of disease activity in a 1-year follow-up study of patients with axial spondyloarthritis treated with tumour necrosis factor alpha inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Sørensen, Inge Juul; Hermann, Kay-Geert A; Madsen, Ole Rintek; Tvede, Niels; Hansen, Michael Sejer; Thamsborg, Gorm; Andersen, Lis Smedegaard; Majgaard, Ole; Loft, Anne Gitte; Erlendsson, Jon; Asmussen, Karsten Heller; Johansen, Julia S; Jurik, Anne Grethe; Møller, Jakob Møllenbach; Hasselquist, Maria; Mikkelsen, Dorrit; Skjødt, Thomas; Hansen, Annette; Østergaard, Mikkel

    2010-01-01

    To investigate construct validity and responsiveness of the novel ankylosing spondylitis (AS) disease activity score (ASDAS) in patients with spondyloarthritis (SpA).......To investigate construct validity and responsiveness of the novel ankylosing spondylitis (AS) disease activity score (ASDAS) in patients with spondyloarthritis (SpA)....

  16. A comparison of disease burden in rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis.

    Directory of Open Access Journals (Sweden)

    Brigitte Michelsen

    Full Text Available The main objective of this study was to compare disease burden in rheumatoid arthritis (RA, psoriatic arthritis (PsA and axial spondyloarthritis (ax-SpA.In this cross-sectional study, all the RA (1093, PsA (365 and ax-SpA (333 patients who visited the out-patient clinic of the Hospital of Southern Norway Trust during the year 2013 were included; the RA patients all had a RA diagnosis verified by the treating rheumatologist, the PsA patients all fulfilled the ClASsification for Psoriatic ARthritis (CASPAR criteria and the ax-SpA patients all fulfilled the Assessment of SpondyloArthritis international Society (ASAS classification criteria for ax-SpA. Patient-reported health status, demographic variables, medications, and composite scores of disease activity were assessed. The main analyses were performed using General Linear Models adjusted for age, sex and multiple comparisons. Correlation analyses were performed using Spearman's rho.The reported pain, joint pain, patient's global assessment and fatigue were similar in PsA and ax-SpA, but significantly lower in RA. The 28-joint Disease Activity Score (DAS28 (0.3±0.1, p = 0.003, Clinical Disease Activity Index (CDAI (1.0±0.4, p = 0.028 and Routine Assessment of Patient Index Data 3 (RAPID3 (0.4±0.1, p = 0.004 were all significantly higher in PsA vs. RA. RAPID3 showed moderate to high correlation with DAS28 (rho = 0.521, p<0.001 and CDAI (rho = 0.768, p<0.001 in RA and PsA, and with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI (rho = 0.902, p<0.001 and Bath Ankylosing Spondylitis Functional Index (BASFI (0.865, p<0.001 in ax-SpA and PsA.In conclusion, patient- reported outcome measures were similar in our population of PsA and ax-SpA patients, but significantly lower for the RA patients. Composite disease activity measures were lower in RA than in PsA and ax-SpA, but the magnitude of these differences was small and probably not of clinical significance. Our study indicates that

  17. An appraisal of golimumab in the treatment of severe, active nonradiographic axial spondyloarthritis

    Directory of Open Access Journals (Sweden)

    Paccou J

    2016-07-01

    Full Text Available Julien Paccou, René-Marc Flipo Department of Rheumatology, Lille University Hospital, Lille, France Abstract: Golimumab (Simponi® is a fully human tumor necrosis factor α inhibitor (TNFi antibody administered subcutaneously. In the European Union, golimumab is indicated for the treatment of adults with severe, active axial spondyloarthritis (axSpA, which includes both ankylosing spondylitis (AS and nonradiographic axSpA (nr-axSpA. In the US, it is indicated for the treatment of adults with active AS only. This article reviews the efficacy and tolerability of golimumab in nr-axSpA patients compared to other TNFi agents (adalimumab, infliximab, etanercept, and certolizumab pegol. In one ongoing, well-designed controlled study (GO-AHEAD, data at 16 weeks showed that treatment with golimumab (50 mg every 4 weeks was effective in improving the clinical signs and symptoms of disease in nr-axSpA patients. In addition, 16 weeks of treatment with golimumab reduced inflammation in the sacroiliac joints and spine in patients with nr-axSpA. Moreover, objective evidence of active inflammation at baseline, such as a positive magnetic resonance imaging scan and/or an elevated CRP level, was a good predictor of treatment response to golimumab. Golimumab was generally well tolerated in this study, with a tolerability profile consistent with that seen in previous clinical trials for other indications. Although additional long-term data are needed, current evidence indicates that golimumab is an effective option for the treatment of nr-axSpA. However, in the absence of comparative head-to-head trials, there is no recommended hierarchy for the first prescription of a TNFi agent for the treatment of either nr-axSpA or AS. Keywords: axial spondyloarthritis, nonradiographic axial spondyloarthritis, ankylosing spondylitis, golimumab, tumor necrosis factor α inhibitor, therapy

  18. Evolving "Diagnostic" Criteria for Axial Spondyloarthritis in the Context of Anterior Uveitis.

    Science.gov (United States)

    Rosenbaum, James T

    2016-08-01

    Anterior uveitis is far more common than intermediate, posterior or panuveitis. About 50% of patients with acute anterior uveitis are HLA B27+. Those who are HLA B27+ are highly likely to have associated back, joint, or tendon disease. The majority of patients with acute anterior uveitis and inflammatory low back pain are suffering from axial spondyloarthritis and radiographic evidence for abnormal sacroiliac joints is not required to make this diagnosis. Received 12 October 2015; revised 31 January 2016; accepted 16 February 2016; published online 12 April 2016. PMID:27070270

  19. Physical activity in axial spondyloarthritis-tails from bench to bedside.

    Science.gov (United States)

    Gensler, Lianne S

    2016-06-01

    Physical therapy and exercise (recreational activity) are the cornerstones of non-pharmacologic therapy in axial spondyloarthritis (AxSpA) [1, 2]. These are components of physical activity, though physical activity is made up of activities beyond these and also include occupational activity. Not all activities in AxSpA appear to derive the same benefit for patients. In fact, it might be that while some activities are extremely beneficial for disease activity, function, and other outcomes, other activities may be harmful for the disease. The following review will examine animal model-based evidence and epidemiologic studies on physical activity in AxSpA. PMID:27118200

  20. Analysis of HLA-B15 and HLA-B27 in spondyloarthritis with peripheral and axial clinical patterns

    OpenAIRE

    Londono, John; Santos, Ana Maria; Peña, Paola; Calvo, Enrique; Espinosa, Luis R; John D Reveille; Vargas-Alarcon, Gilberto; Jaramillo, Carlos A.; Valle-Oñate, Rafael; Avila, Mabel; Romero, Consuelo; Medina, Juan F.

    2015-01-01

    Objective Human leucocyte antigen (HLA) B27 and HLA-B15 are associated with spondyloarthritis (SpA). Recent Assessment of SpondyloArthritis international Society (ASAS) criteria emphasise a distinction between SpA with axial and peripheral patterns. We analysed whether HLA-A, HLA-B and HLA-DRB1 alleles could associate with these patterns. Methods We studied 100 healthy individuals and 178 patients with SpA according to European Spondyloarthropathy Study Group (ESSG) criteria. Patients were th...

  1. Recent Advances in Imaging of the Axial Skeleton in Spondyloarthritis for Diagnosis, Assessment of Treatment Effect, and Prognostication

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Maksymowych, Walter P

    2015-01-01

    In the last few years, many studies have investigated the role of imaging for improved diagnosis, assessment of treatment effects, and determining prognosis in patients with axial spondyloarthritis (SpA). Recent research has primarily focused on the utility of magnetic resonance imaging (MRI) for...... improved diagnosis of patients with non-radiographic axial SpA, and in particular on the classification utility of the MRI criteria as defined by the Assessment of Spondyloarthritis International Society (ASAS). New and more sensitive methods for evaluation of MRI of the sacroiliac joints have been...... developed and have provided insight into effects of treatment on structural progression and the interrelationships between different lesions visualized by MRI. This review gives an overview of the recent advances in imaging of the axial skeleton in axial SpA from a clinical perspective....

  2. Human brucellosis mimicking axial spondyloarthritis: a challenge for rheumatologists when applying the 2009 ASAS criteria.

    Science.gov (United States)

    Ye, Cong; Shen, Gui-Fen; Li, Shou-Xin; Dong, Ling-Li; Yu, Yi-Kai; Tu, Wei; Zhu, Ying-Zi; Hu, Shao-Xian

    2016-06-01

    Although the development of the 2009 SpA classification criteria by Assessment of SpondyloArthritis international Society (ASAS) represents an important step towards a better definition of the early disease stage particularly in axial spondyloarthritis (axSpA), the specificity of the criteria has been criticized these days. As the commonest zoonotic infection worldwide, human brucellosis can mimic a large number of diseases, including SpA. This study was performed to determine the frequency of rheumatologic manifestations in patients with brucellosis and the chance of misdiagnosing them as having axSpA in central China. The results showed that clinical manifestations of axSpA could be observed in brucellosis. Over half of patients had back pain, and one fifth of the patients with back pain were less than 45 years old at onset and had the symptom for more than 3 months. Two young males were falsely classified as suffering from axSpA according to the ASAS criteria, and one with MRI proved sacroiliitis was once given Etanercept for treatment. Therefore, differential diagnosis including human brucellosis should always be kept in mind when applying the ASAS criteria, even in traditionally non-endemic areas. PMID:27376805

  3. IL-17 Inhibition: Emerging Perspectives in the Future Management of Axial Spondyloarthritis

    Directory of Open Access Journals (Sweden)

    Atul Deodhar

    2015-07-01

    Full Text Available The meeting was opened by Prof Atul Deodhar who introduced the prevalence, epidemiology, and clinical features of axial spondyloarthritis (axSpA, and discussed the ongoing unmet needs in the management of axSpA. Prof Dirk Elewaut described the role of the interleukin-17 (IL-17 pathway in the pathogenesis of axSpA. Prof Dominique Baeten reviewed the latest clinical data from existing and emerging therapies for axSpA. Finally, Prof Xenofon Baraliakos discussed recent advances in the assessment of bone inflammation and structural damage in axSpA. Each discussion was followed by questions and answers. The meeting was concluded with an interactive final discussion between the panellists and the audience, with concluding remarks by Prof Atul Deodhar.

  4. The oral microbiome of patients with axial spondyloarthritis compared to healthy individuals

    Science.gov (United States)

    Bisanz, Jordan E.; Suppiah, Praema; Thomson, W. Murray; Milne, Trudy; Yeoh, Nigel; Nolan, Anita; Ettinger, Grace; Reid, Gregor; Gloor, Gregory B.; Burton, Jeremy P.; Cullinan, Mary P.

    2016-01-01

    Background. A loss of mucosal tolerance to the resident microbiome has been postulated in the aetiopathogenesis of spondyloarthritis, thus the purpose of these studies was to investigate microbial communities that colonise the oral cavity of patients with axial spondyloarthritis (AxSpA) and to compare these with microbial profiles of a matched healthy population. Methods. Thirty-nine participants, 17 patients with AxSpA and 22 age and gender-matched disease-free controls were recruited to the study. For patients with AxSpA, disease activity was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). All participants underwent a detailed dental examination to assess oral health, including the presence of periodontal disease assessed using probing pocket depth (PPD). Plaque samples were obtained and their bacterial populations were profiled using Ion Torrent sequencing of the V6 region of the 16S rRNA gene. Results.Patients with AxSpA had active disease (BASDAI 4.1 ± 2.1 [mean ± SD]), and a significantly greater prevalence of periodontitis (PPD ≥ 4 mm at ≥4 sites) than controls. Bacterial communities did not differ between the two groups with multiple metrics of α and β diversity considered. Analysis of operational taxonomic units (OTUs) and higher levels of taxonomic assignment did not provide strong evidence of any single taxa associated with AxSpA in the subgingival plaque. Discussion. Although 16S rRNA gene sequencing did not identify specific bacterial profiles associated with AxSpA, there remains the potential for the microbiota to exert functional and metabolic influences in the oral cavity which could be involved in the pathogenesis of AxSpA. PMID:27330858

  5. Golimumab in radiographic and nonradiographic axial spondyloarthritis: a review of clinical trials

    Directory of Open Access Journals (Sweden)

    Toussirot E

    2016-07-01

    Full Text Available Eric Toussirot,1–5 Charline Vauchy,1 Delphine Binda,1 Fabrice Michel6 1Clinical Investigation Center in Biotherapy, Intitut National de la Santé et de la Recherche Médicale CIC-1431, 2Fédération Hospitalo-Universitaire Integrated Center for Research in inflammatory Diseases, 3Department of Rheumatology, University Hospital of Besançon, Besançon, France; 4Department of Therapeutics, 5Equipe d’accueil EA 4266: “Pathogenic Agents and Inflammation”, University of Franche-Comté, 6Department of Neuromuscular Examinations and Diseases, University Hospital of Besançon, Besançon, FranceAbstract: Axial spondyloarthritis (Ax SpA refers to chronic inflammatory rheumatic diseases that mainly affect the axial skeleton, leading to erosions and new bone formation in the sacroiliac joints and/or the spine. Ax SpA includes the radiographic form of the disease, ie, ankylosing spondylitis (AS, and the nonradiographic Ax SpA (non-Rx Ax SpA forms. Anti-tumor necrosis factor alpha (TNFα agents are used in the treatment of Ax SpA in patients who do not respond to or are intolerant to nonsteroidal anti-inflammatory drugs. In these patients, anti-TNFα agents show promising results by targeting the inflammatory process and providing symptomatic relief. Golimumab is a fully human anti-TNFα agent that is currently approved for the treatment of both AS and non-Rx Ax SpA in Europe. This review focuses on the results of clinical trials with golimumab for the treatment of AS (GO-RAISE studies and non-Rx Ax SpA (GO-AHEAD study and on the effects of this agent on imaging findings (radiographic progression, magnetic resonance imaging inflammation as well as on biological parameters. Overall, golimumab is a valid therapeutic option in patients with AS and non-Rx Ax SpA in Europe.Keywords: anti-TNFα, golimumab, axial spondyloarthritis

  6. Identification of plasma microRNA expression profile in radiographic axial spondyloarthritis-a pilot study.

    Science.gov (United States)

    Magrey, Marina N; Haqqi, Tariq; Haseeb, Abdul

    2016-05-01

    At present, there are no studies that have established a microRNA (miRNA)-based signature profile in patients with radiographic axial spondyloarthritis (rad-axial SpA), and we hypothesized that these patients may have aberrantly expressed circulating miRNAs reflective of underlying disease and inflammation. This study aims to determine the expression profile of miRNAs in plasma of patients with rad-axial SpA and compare it with healthy, age, and sex-matched controls. Fifteen subjects with rad-axial SpA based on ASAS classification criteria and 5 controls were recruited from our local SpA registry. Demographic data were collected and disease activity was measured using Bath Ankylosing Spondylitis Disease Activity Index (BASDI). Peripheral blood samples (5 ml) were obtained from eligible consenting patients and controls. RNA from the plasma was prepared using miRNeasy kit (Qiagen) by a modified protocol. Expression of 175 miRNAs was screened in the plasma of all 15 patients and 5 controls using serum/plasma miRNA PCR arrays (Exiqon Inc. Woburn, MA) essentially following the manufacturer's instructions. Real-time PCR was carried out on StepOne Plus (Applied Biosystems) and the data was extracted and analyzed using ExiGen Enterprise software (MultiD, Göteborg, Sweden). Potential miRNA targets were identified using bioinformatics. ESR and CRP levels were measured by standard laboratory methods. We identified 7 differentially expressed miRNAs (2 upregulated and 5 downregulated). miR-34a, which was overexpressed in patients with rad-axial SpA, was predicted to target BMP-3 mRNA by TargetscanS and PicTar miRNA target algorithms. miR-150 was downregulated in all of the samples analyzed by us using the TaqMan Gene Expression assay. The most repressed miRNA was miR-16 and is predicted to regulate the expression of activin A receptor (ACVR2B), a receptor for growth, and differentiation factor-5 (GDF-5). Our data indicates that (1) patients with axial SpA, as compared to

  7. Pyoderma gangrenosum, acne conglobata, suppurative hidradenitis, and axial spondyloarthritis: efficacy of anti-tumor necrosis factor α therapy.

    Science.gov (United States)

    Bruzzese, Vincenzo

    2012-12-01

    We report the case of a patient with a simultaneous presence of pyoderma gangrenosum, acne conglobata, suppurative hidradenitis, and axial spondyloarthritis. This condition differs from both the PASH (pyoderma gangrenosum, acne, and suppurative hidradenitis) syndrome, in which arthritis is absent, and the PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome, in which suppurative hidradenitis is lacking. Our patient failed to respond to etanercept therapy, whereas all dermatologic and rheumatic manifestations completely regressed following infliximab infusion. We therefore propose that simultaneous presence of pyoderma gangrenosum, acne conglobata, suppurative hidradenitis, and seronegative spondyloarthritis might represent a distinct syndrome that could be termed the PASS syndrome. Tumor necrosis factor α therapies seem to play selective roles. PMID:23188209

  8. Spondyloarthritis-related and degenerative MRI changes in the axial skeleton--an inter- and intra-observer agreement study

    DEFF Research Database (Denmark)

    Arnbak, Bodil; Jensen, Tue Secher; Manniche, Claus; Zejden, Anna; Egund, Niels; Jurik, Anne Grethe

    2013-01-01

    The Back Pain Cohort of Southern Denmark (BaPa Cohort) was initiated with the aim of evaluating the clinical relevance of magnetic resonance imaging (MRI) in the diagnosis of early spondyloarthritis (SpA). In order to facilitate the collection of MRI data for this study, an electronic evaluation...... form was developed including both SpA-related and degenerative axial changes. The objective of the current study was to assess the intra- and inter-observer agreement of the MRI changes assessed....

  9. Does the reason for discontinuation of a first TNF inhibitor influence the effectiveness of a second TNF inhibitor in axial spondyloarthritis?

    DEFF Research Database (Denmark)

    Ciurea, Adrian; Exer, Pascale; Weber, Ulrich;

    2016-01-01

    BACKGROUND: With regard to switching tumor necrosis factor inhibitors (TNFi) in axial spondyloarthritis (axSpA), conflicting results have been reported as to whether the effectiveness of a second TNFi depends on the reason for discontinuation of the first TNFi. METHODS: Patients with a clinical d...

  10. CLINICAL PROFILE OF PATIENTS WITH EARLY AXIAL SPONDYLOARTHRITIS (RUSSIAN COHORT OF PATIENTS

    Directory of Open Access Journals (Sweden)

    E. E. Gubar'

    2014-01-01

    Full Text Available Objective: to study clinical manifestations of axial spondyloarthritis (axSpA fulfilling ASAS criteria and to evaluate Russian version of modified New York criteria for the diagnosis of AS in Russian patients.Subjects and methods. Authors examined 73 patients aged 18–45 years suffering from inflammatory back pain for a period from 3 months to 5 years. BASDAI and ASDAS-CRP were used to assess activity, whereas BASFI – to evaluate functional status. Examination included: assessment of HLA-B27 rate, X-ray of pelvis and lumbar spine, ultrasonography of hip joints and calcaneal regions, magnetic-resonance imaging (MRI of sacroiliac joints, lumbar spine and hip joints (if clinical signs of injury are present, densitometry of lumbar spine (LII–IV and femoral neck.Results. Mean age of patients was 28.3±6.4 years, mean duration of disease – 19.9±14.4 months. HLA-B27 was found in 94.5% of patients. Mean BASDAI value was 4.1±1.9; ASDAS – 2.7±1.3; BASFI – 2.6±2.1. Peripheral arthritis was observed in 65.8% of cases, coxitis – in 31.5%, calcaneal enthesitis – in 61.6%, dactylitis – in 19.2%, low bone mineral density – in 17.8%. MRI showed inflammatory changes of axial skeleton in 84.9% of patients, active sacroiliitis (SI – in 72.6%. X-ray revealed definite SI in 49.3% of patients («classic» AS. According to MRI data, 30.1% of patients with active SI and without structural changes of sacroiliac joints had pre-radiological stage of AS (by Russian version of modified New York criteria. 74.0% of patients fulfilled both sets of ASAS criteria for axSpA, 5.5% – met only I criteria set, whereas 20.5% – only II criteria set. Three groups of patients were defined. The first included patients with radiologically proven SI, the second – with MRI-proven SI and the third – patients without SI. Significant difference between the groups was detected either by gender (number of males in groups I and II exceeded that in group

  11. Anti-TNF agents for the treatment of active non-radiographic axial spondyloarthritis

    Directory of Open Access Journals (Sweden)

    I. Olivieri

    2013-03-01

    Full Text Available The spondyloarthritis (SpA complex includes ankylosing spondylitis (AS, reactive arthritis, psoriatic arthritis, arthritis related to inflammatory bowel disease and forms that do not meet established criteria for these definite categories which are designated as undifferentiated SpA. In the early 1990s, two sets of classification criteria were suggested with the purpose to cover the whole clinical spectrum of SpA: the Amor criteria and the European Spondylarthropathy Study Group (ESSG criteria...

  12. Comparison of rates of referral and diagnosis of axial spondyloarthritis before and after an ankylosing spondylitis public awareness campaign.

    Science.gov (United States)

    Harrison, Andrew A; Badenhorst, Christoffel; Kirby, Sandra; White, Douglas; Athens, Josie; Stebbings, Simon

    2014-07-01

    The objective of this research is to measure the effect of a national ankylosing spondylitis (AS) public awareness campaign on numbers of referrals for suspected AS and numbers of cases diagnosed with axial spondyloarthritis (SpA). A television advertising campaign was conducted by Arthritis New Zealand in 2011 to raise public awareness of AS. A retrospective analysis was made of referrals received by the three rheumatology services 3 months before the campaign started and 3 months after the campaign ended. The age, gender, number of referrals for suspected AS and number of referrals resulting in a diagnosis of axial SpA were recorded. Independent analysis showed that the awareness campaign reached 82 % of the primary target audience. In the 3 months after the awareness campaign, there was a significant increase in referrals for suspected AS compared with the 3 months before the campaign (54 vs. 88, 63 %, p = 0.0056). Referrals for other conditions did not change. The number of referrals resulting in a diagnosis of axial SpA also increased (27 vs. 44, 63 %, p = 0.0576). The mean ages of the patients referred and of those diagnosed with axial SpA did not change. The male/female ratio was 1:1 among the referrals for suspected AS and 2:1 in referrals diagnosed with axial SpA, before and after the campaign. The Arthritis New Zealand AS public awareness campaign was associated with a significant increase in referrals to rheumatology services for suspected AS and an increase in the diagnosis of axial SpA in clinics. PMID:24609715

  13. Predictive validity of the ASAS classification criteria for axial and peripheral spondyloarthritis after follow-up in the ASAS cohort

    DEFF Research Database (Denmark)

    Sepriano, Alexandre; Landewé, Robert; van der Heijde, Désirée;

    2016-01-01

    OBJECTIVE: To establish the predictive validity of the Assessment of SpondyloArthritis international Society (ASAS) spondyloarthritis (SpA) classification criteria. METHODS: 22 centres (N=909 patients) from the initial 29 ASAS centres (N=975) participated in the ASAS-cohort follow-up study. Patie...

  14. CLINICAL HETEROGENEITY OF EARLY AXIAL SPONDYLOARTHRITIS: ANALYSIS OF CLINICAL AND RADIOLOGICAL FINDINGS IN CRIMEA’S PATIENTS

    Directory of Open Access Journals (Sweden)

    A. V. Petrov

    2015-01-01

    Full Text Available Ankylosing spondylitis (AS is characterized  by considerable variation in the rate of development of structural changes in the vertebral column and joints. As of now, the clinical and laboratory predictors of progression of undifferentiated axial spondyloarthritis  (SpA to AS have not been adequately explored.         Objective: to study the clinical features of early axial SpA in view of radiographic changes in the sacroiliac and hip joints and spinal column.Subjects and methods. The rate of different clinical syndromes of axial SpA was analyzed in 162 patients. The study included less than 35-year-old  patients with a 2-to-5-year history of axial SpA that was first diagnosed according to the 2009 ASAS criteria, by excluding psoriatic and reactive arthritis and inflammatory  bowel diseaserelated arthritis.Results and discussion. The examinees were diagnosed with undifferentiated SpA (52.5%, advanced AS (43.2%, and late AS (in the presence of syndesmophytes (4.3%. 38.3% of patients had peripheral arthritis (PA, 8.6% – dactylitis, 28.4% – enthesitis , and 4.9% – uveitis. The patients with advanced AS had higher C-reactive  protein (CRP  levels (38.7 [22.3; 45.8] and lower rates of PA (27% than those with undifferentiated axial SpA (14.4 [4.2;18.6] mg/l and 48%, respectively; p < 0.05. The patients with late AS had more commonly enthesitis (71.4% and HLA-B27 (100% than those with undifferentiated axial SpA (31.4 and 78.8% and those with advanced AS (22.3 and 81.4%, respectively; p < 0.05. Radiographic  narrowing of the hip joint space was accompanied by increases in the rate of enthesitis up to 56.2% and HLA-B27 up to 93.7% (the remaining patients exhibited 24.6 and 79.5% increases, respectively (p < 0.05.Conclusion. High CRP levels, presence of enthesitis and HLA-B27 may be regarded as predictors for rapid progression of structural changes in patients with early axial SpA.DOI: http://dx.doi.org/10.14412/1995-4484-2015-139-142

  15. Candidate lesion-based criteria for defining a positive sacroiliac joint MRI in two cohorts of patients with axial spondyloarthritis

    DEFF Research Database (Denmark)

    Weber, Ulrich; Østergaard, Mikkel; Lambert, Robert G W;

    2015-01-01

    OBJECTIVE: To determine candidate lesion-based criteria for a positive sacroiliac joint (SIJ) MRI based on bone marrow oedema (BMO) and/or erosion in non-radiographic axial spondyloarthritis (nr-axSpA); to compare the performance of lesion-based criteria with global evaluation by expert readers...... clinical examination, pelvic radiography and laboratory values as having nr-axSpA (n=51), ankylosing spondylitis (n=34) or non-specific back pain (n=72). Four blinded readers assessed SIJ MRI, recording the presence/absence of SpA by concomitant global evaluation of T1-weighted spin echo (T1SE) and short τ...... inversion recovery (STIR) scans and, thereafter, whether BMO and/or erosion were present/absent in each SIJ quadrant of each MRI slice. We derived candidate lesion-based criteria based on the number of SIJ quadrants with BMO and/or erosion and calculated mean sensitivity and specificity for SpA. RESULTS...

  16. External Validation of a Referral Rule for Axial Spondyloarthritis in Primary Care Patients with Chronic Low Back Pain.

    Directory of Open Access Journals (Sweden)

    Lonneke van Hoeven

    Full Text Available To validate and optimize a referral rule to identify primary care patients with chronic low back pain (CLBP suspected for axial spondyloarthritis (axSpA.Cross-sectional study with data from 19 Dutch primary care practices for development and 38 for validation.Primary care patients aged 18-45 years with CLBP existing more than three months and onset of back pain started before the age of 45 years.The number of axSpA patients according to the ASAS criteria.The referral rule (CaFaSpA referral rule was developed using 364 CLBP patients from 19 primary care practices and contains four easy to use variables; inflammatory back pain, good response to nonsteriodal anti-inflammatory drugs, family history of spondyloarthritis and a back pain duration longer than five years. This referral rule is positive when at least two variables are present. Validation of the CaFaSpA rule was accomplished in 579 primary care CLBP patients from 38 practices from other areas. Performance of the referral rule was assessed by c-statistic and calibration plot. To fit the final referral rule the development and validation datasets were pooled leading to a total study population of 943 primary care participants.The referral rule was validated in 579 patients (41% male, mean age 36 (sd7.0. The percentage of identified axSpA patients was 16% (n=95. External validation resulted in satisfactory calibration and reasonable discriminative ability (c-statistics 0.70 [95% CI, 0.64-0.75]. In the pooled dataset sensitivity and specificity of the referral rule were 75% and 58%.The CaFaSpA referral rule for axSpA consists of four easy to use predictors for primary care physicians and has a good predictive value in this validation study. The referral rule has the potential to be a screening tool for primary care by identifying CLBP patients suspected for axSpA.

  17. Diagnostic utility of candidate definitions for demonstrating axial spondyloarthritis on magnetic resonance imaging of the spine

    DEFF Research Database (Denmark)

    Weber, Ulrich; Zhao, Zheng; Rufibach, Kaspar;

    2015-01-01

    patients with nonspecific back pain. A threshold of ≥6 CILs had moderate to substantial diagnostic utility (positive LR 13.26 and 6.74 in cohorts A and B, respectively) in nonradiographic axial SpA, while ≥4 CILs showed small diagnostic utility (positive LR 3.83 and 2.72 in cohorts A and B, respectively...

  18. Head-to-toe whole-body MRI in psoriatic arthritis, axial spondyloarthritis and healthy subjects

    DEFF Research Database (Denmark)

    Poggenborg, René Panduro; Pedersen, Susanne Juhl; Eshed, Iris;

    2015-01-01

    OBJECTIVES: By whole-body MRI (WBMRI), we aimed to examine the frequency and distribution of inflammatory and structural lesions in PsA patients, SpA patients and healthy subjects (HSs), to introduce global WBMRI inflammation/damage scores, and to assess WBMRI's reproducibility and correlation with...... conventional MRI (convMRI). METHODS: WBMRI (3.0-T) of patients with peripheral PsA (n = 18) or axial SpA (n = 18) and of HS (n = 12) was examined for proportion of evaluable features (readability) and the presence and pattern of lesions in axial and peripheral joints. Furthermore, global WBMRI scores of...... inflammation and structural damage were constructed, and WBMRI findings were compared with clinical measures and convMRI (SpA/HS: spine and SI joints; PsA/HS: hand). RESULTS: The readability (92-100%) and reproducibility (intrareader intraclass correlation coefficient: 0.62-1.0) were high in spine/SI joint...

  19. Efficacy of high intensity exercise on disease activity and cardiovascular risk in active axial spondyloarthritis: a randomized controlled pilot study.

    Directory of Open Access Journals (Sweden)

    Silje Halvorsen Sveaas

    Full Text Available BACKGROUND: Physical therapy is recommended for the management of axial spondyloarthritis (axSpA and flexibility exercises have traditionally been the main focus. Cardiovascular (CV diseases are considered as a major health concern in axSpA and there is strong evidence that endurance and strength exercise protects against CV diseases. Therefore, the aim of this study was to investigate the efficacy of high intensity endurance and strength exercise on disease activity and CV health in patients with active axSpA. METHODS: In a single blinded randomized controlled pilot study the exercise group (EG performed 12 weeks of endurance and strength exercise while the control group (CG received treatment as usual. The primary outcome was the Ankylosing Spondylitis (AS Disease Activity Score (ASDAS. Secondary outcomes included patient reported disease activity (Bath AS Disease Activity Index [BASDAI], physical function (Bath AS Functional Index [BASFI], and CV risk factors measured by arterial stiffness (Augmentation Index [Alx] and Pulse Wave Velocity [PWV], cardiorespiratory fitness (VO2 peak and body composition. ANCOVA on the post intervention values with baseline values as covariates was used to assess group differences, and Mann Whitney U-test was used for outcomes with skewed residuals. RESULTS: Twenty-eight patients were included and 24 (EG, n = 10, CG, n = 14 completed the study. A mean treatment effect of -0.7 (95%CI: -1.4, 0.1 was seen in ASDAS score. Treatment effects were also observed in secondary outcomes (mean group difference [95%CI]: BASDAI: -2.0 (-3.6, -0.4, BASFI: -1.4 (-2.6, -0.3, arterial stiffness (estimated median group differences [95% CI]: AIx (%: -5.3 (-11.0, -0.5, and for PVW (m/s: -0.3 (-0.7, 0.0, VO2 peak (ml/kg/min (mean group difference [95%CI]: 3.7 (2.1, 5.2 and trunk fat (%: -1.8 (-3.0, -0.6. No adverse events occurred. CONCLUSION: High intensity exercise improved disease activity and reduced CV risk factors in

  20. Comparison of non-radiographic axial spondyloarthritis and ankylosing spondylitis patients - baseline characteristics, treatment adherence, and development of clinical variables during three years of anti-TNF therapy in clinical practice

    DEFF Research Database (Denmark)

    Wallman, Johan K; Kapetanovic, Meliha C; Petersson, Ingemar F;

    2015-01-01

    BACKGROUND: The relationship between non-radiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) is currently debated. Using observational data from the South Swedish Arthritis Treatment Group register, we thus aimed to compare clinical development and treatment adherence ...

  1. Assessment of MRI abnormalities of the sacroiliac joints and their ability to predict axial spondyloarthritis: a retrospective pilot study on 110 patients

    International Nuclear Information System (INIS)

    To assess sacroiliac joint (SIJ) modifications on MRI and their ability to predict axial spondyloarthritis (SpA) with the purpose of identifying parameters for future prospective studies. Retrospective study was carried out of 110 consecutive patients referred for SIJ MRI with coronal, axial short TI inversion recovery (STIR), and axial T1 sequences over 6 months. Factors associated with SpA, including MRI SIJ modifications (fat deposition, structural abnormalities on T1-weighted images, and bone marrow edema [BME] on STIR sequences) and age were explored using multivariate logistic regression. The reference diagnosis was made 1-1.5 years later based on clinical, radiological, and biological findings, according to Assessment of SpondyloArthritis International Society (ASAS) criteria. Twenty-eight patients were diagnosed with SpA (female/male: 19/9, age 41 ± 13 years). Abnormal findings were found in up to 21 % of patients without SpA (including 11 % with BME), versus 64 % of SpA patients (50 % with BME). A threshold age of 42.6 years was found to discriminate SpA patients (ROC AUC: 0.71, 95 % CI: 0.59-0.81). BME location in the sacral (OR: 7.07 [1.05, 47.6], p = 0.044) and both sacral and iliac areas (OR: 36.0 [5.61, 231], p = 0.0002), as well as age (OR: 0.95 [0.92, 0.98], p = 0.0019) were found to be independent predictors of SpA. 83.6 % of patients were effectively diagnosed using BME location and patient age in a classification and regression tree (CART) algorithm (sensitivity: 61 %, specificity: 91 %, PPV: 71 %, NPV: 87 %). The BME location combined with the patient's age (threshold 42.6 years) could help predict SpA. Further studies are required before these features can be used by radiologists to boost their confidence in reporting SIJ MRI. (orig.)

  2. IgG subclass antibodies to human and bacterial HSP60 are not associated with disease activity and progression over time in axial spondyloarthritis

    DEFF Research Database (Denmark)

    Carlsen, Thomas Gelsing; Hjelholt, Astrid; Jurik, Anne Grethe;

    2013-01-01

    INTRODUCTION: Spondyloarthritis (SpA), an interrelated group of rheumatic diseases, has been suggested to be triggered by bacterial infections prior to the development of an autoimmune response that causes inflammation of the spinal and peripheral joints. Because human heat shock protein 60 (HSP60......), recently renamed HSPD1, and bacterial HSP60 are highly homologous, immunological cross-reactivity has been proposed as a mechanism of disease initiation. However, previous investigations of the humoral immune response to HSP60 in SpA patients have lacked determination of immunoglobulin G (IgG) subclasses...... HSP60 of three reactive arthritis-related bacteria; human HSP60; and the microorganisms Chlamydia trachomatis and C. pneumoniae were determined by ELISA. Serum samples collected from 2004 to 2006 and in 2010 and 2011 from 39 axial SpA patients were analyzed and compared with samples from 39 healthy...

  3. Fat Metaplasia on Sacroiliac Joint Magnetic Resonance Imaging at Baseline Is Associated with Spinal Radiographic Progression in Patients with Axial Spondyloarthritis.

    Directory of Open Access Journals (Sweden)

    Kwi Young Kang

    Full Text Available To study the relationship between inflammatory and structural lesions in the sacroiliac joints (SIJs on MRI and spinal progression observed on conventional radiographs in patients with axial spondyloarthritis (axSpA.One hundred and ten patients who fulfilled the ASAS axSpA criteria were enrolled. All underwent SIJ MRI at baseline and lumbar spine radiographs at baseline and after 2 years. Inflammatory and structural lesions on SIJ MRI were scored using the SPondyloArthritis Research Consortium of Canada (SPARCC method. Spinal radiographs were scored using the Stoke AS Spinal Score (SASSS. Multivariate logistic regression analysis was performed to identify predictors of spinal progression.Among the 110 patients, 25 (23% showed significant radiographic progression (change of SASSS≥2 over 2 years. There was no change in the SASSS over 2 years according to the type of inflammatory lesion. Patients with fat metaplasia or ankyloses on baseline MRI showed a significantly higher SASSS at 2 years than those without (p<0.001. According to univariate logistic regression analysis, age at diagnosis, HLA-B27 positivity, the presence of fat metaplasia, erosion, and ankyloses on SIJ MRI, increased baseline CRP levels, and the presence of syndesmophytes at baseline were associated with spinal progression over 2 years. Multivariate analysis identified syndesmophytes and severe fat metaplasia on baseline SIJ MRI as predictive of spinal radiographic progression (OR, 14.74 and 5.66, respectively.Inflammatory lesions in the SIJs on baseline MRI were not associated with spinal radiographic progression. However, fat metaplasia at baseline was significantly associated with spinal progression after 2 years.

  4. Assessment of MRI abnormalities of the sacroiliac joints and their ability to predict axial spondyloarthritis: a retrospective pilot study on 110 patients

    Energy Technology Data Exchange (ETDEWEB)

    Larbi, Ahmed; Viala, Pierre; Baron, Marie Pierre; Taourel, Patrice; Cyteval, Catherine [Hopital Lapeyronie, Medical Imaging Department, Montpellier Cedex 5 (France); Molinari, Nicolas [Hopital Lapeyronie, Medical Data Processing Department, Montpellier Cedex 5 (France); Lukas, Cedric [Hopital Lapeyronie, Rheumatology Department, Montpellier Cedex 5 (France)

    2014-03-15

    To assess sacroiliac joint (SIJ) modifications on MRI and their ability to predict axial spondyloarthritis (SpA) with the purpose of identifying parameters for future prospective studies. Retrospective study was carried out of 110 consecutive patients referred for SIJ MRI with coronal, axial short TI inversion recovery (STIR), and axial T1 sequences over 6 months. Factors associated with SpA, including MRI SIJ modifications (fat deposition, structural abnormalities on T1-weighted images, and bone marrow edema [BME] on STIR sequences) and age were explored using multivariate logistic regression. The reference diagnosis was made 1-1.5 years later based on clinical, radiological, and biological findings, according to Assessment of SpondyloArthritis International Society (ASAS) criteria. Twenty-eight patients were diagnosed with SpA (female/male: 19/9, age 41 ± 13 years). Abnormal findings were found in up to 21 % of patients without SpA (including 11 % with BME), versus 64 % of SpA patients (50 % with BME). A threshold age of 42.6 years was found to discriminate SpA patients (ROC AUC: 0.71, 95 % CI: 0.59-0.81). BME location in the sacral (OR: 7.07 [1.05, 47.6], p = 0.044) and both sacral and iliac areas (OR: 36.0 [5.61, 231], p = 0.0002), as well as age (OR: 0.95 [0.92, 0.98], p = 0.0019) were found to be independent predictors of SpA. 83.6 % of patients were effectively diagnosed using BME location and patient age in a classification and regression tree (CART) algorithm (sensitivity: 61 %, specificity: 91 %, PPV: 71 %, NPV: 87 %). The BME location combined with the patient's age (threshold 42.6 years) could help predict SpA. Further studies are required before these features can be used by radiologists to boost their confidence in reporting SIJ MRI. (orig.)

  5. New evidence on the management of spondyloarthritis.

    Science.gov (United States)

    Sieper, Joachim; Poddubnyy, Denis

    2016-05-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment for patients with symptomatic axial spondyloarthritis (SpA), who seem to respond best if treated early in the course of disease. The effect of NSAIDs on radiographic disease progression is less clear. Conventional disease-modifying antirheumatic drugs (DMARDs) are not recommended in the treatment of axial SpA, either alone or in combination with TNF blockers. Patients with nonradiographic axial SpA (nr-axSpA) seem to respond as well to TNF blockers as do patients with radiographic axial SpA (ankylosing spondylitis (AS)). However, patients with nr-axSpA should, in addition to a high severity of symptoms, also have objective signs of inflammation, detectable by MRI or by C-reactive protein testing, to be treated with TNF blockers. Whether early TNF-blocker treatment can retard new bone formation needs clarification. In clinical trials, anti-IL-17 agents and TNF blockers showed similar efficacy in patients with AS. The potential of IL-23 blockade for treatment of axial SpA needs to be further investigated. Treatment options for peripheral SpA have been much less thoroughly investigated than those for axial SpA. However, some data indicate that TNF blockers are effective for treating peripheral arthritis, enthesitis and dactylitis, the typical manifestations of peripheral SpA. PMID:27052489

  6. Cartilage collagen type II seromarker patterns in axial spondyloarthritis and psoriatic arthritis: associations with disease activity, smoking and HLA-B27.

    Science.gov (United States)

    Munk, Heidi Lausten; Gudmann, Natasja Staehr; Christensen, Anne Friesgaard; Ejstrup, Leif; Sorensen, Grith Lykke; Loft, Anne Gitte; Bay-Jensen, Anne C; Siebuhr, Anne Sofie; Junker, Peter

    2016-04-01

    The aim of the study was to assess the possible association between type II collagen turnover seromarkers and disease profile in patients with axial spondyloarthritis (SpA) and psoriatic arthritis (PsA). Outpatients with axial SpA (n = 110) or PsA (n = 101) underwent clinical examination including disease activity measures and HLA-B27 typing. The procollagen IIA N-terminal peptide (PIIANP) and a matrix metalloproteinase-generated type II collagen fragment (C2M) were quantified in serum by ELISA. C2M was higher in SpA than in controls, 0.41 versus 0.36 ng/ml (p = 0.004), while PIIANP did not differ between patients and healthy subjects, 2252 versus 2142 ng/ml (p = 0.13). However, DMARD-naïve SpA patients had higher PIIANP, 2461 ng/ml (p = 0.01) and C2M, 0.44 ng/ml (p = 0.0007) levels than controls, and PIIANP correlated with CRP (ρ = 0.34). C2M was lower in SpA smokers, 0.36 ng/ml versus non-smokers, 0.43 ng/ml (p = 0.02), while PIIANP was higher in HLA-B27 positive, 2312 ng/ml versus negative patients, 2021 ng/ml (p = 0.03). In PsA, PIIANP and C2M did not differ between patients and controls, but PIIANP was elevated in patients not receiving DMARDs, 2726 ng/ml. In PsA, PIIANP and C2M did not differ according to smoking and HLA-B27. Cartilage degradation assessed by C2M is increased in SpA irrespective of treatment but not in PsA. Cartilage synthesis reflected by PIIANP is increased in untreated SpA and PsA. PIIANP correlates with CRP in SpA while not in PsA. In DMARD-naïve SpA but not in PsA, HLA-B27 positivity and smoking are associated with a chondro-proliferative metabolic pattern. PMID:26620690

  7. Optimizing the MRI protocol of the sacroiliac joints in Spondyloarthritis: which para-axial sequence should be used?

    Energy Technology Data Exchange (ETDEWEB)

    Giraudo, Chiara; Weber, Michael; Platzgummer, Hannes; Kainberger, Franz; Schueller-Weidekamm, Claudia [Medical University of Vienna, Vienna General Hospital, Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging und Image-guided Therapy, Vienna (Austria); Magnaldi, Silvia [Fondazione Poliambulanza Istituto Ospedaliero, Dipartimento di Radiologia e Diagnostica per Immagini, Brescia (Italy); Puchner, Antonia [Medical University of Vienna, Vienna General Hospital, Division of Rheumatology, Department of Internal Medicine III, Vienna (Austria)

    2016-01-15

    To assess the diagnostic value of para-axial T2w-TSE (paT2) and fat-suppressed proton density (paPD-FS) MRI sequences for the evaluation of the sacroiliac joint (SIJ) of patients with axial Spondylarthritis (SpA). One hundred and six patients with clinical findings suggestive of SpA underwent an MR protocol of the SIJ with additional paPD-FS (41 patients) and paT2 (105 patients). Acute (bone marrow oedema [BME], enthesitis, capsulitis, synovitis) and chronic findings (erosions, ankylosis) were assessed by paPD-FS and compared with the gold standard post-contrast sequences, whereas chronic features (because of the lack of fat suppression) were evaluated on paT2 and compared with pcT1. paPD-FS demonstrated high sensitivity (98.9 %) and specificity (99.1 %) for BME; sensitivity and specificity for synovitis and enthesitis were 100 %; 85.7 % and 100 %, respectively, for capsulitis. paPD-FS and paT2 showed 100 % sensitivity and specificity for ankylosis; for erosions, paT2 demonstrated 85.3 % sensitivity and 100 % specificity, whereas paPD-FS, respectively, 98 % and 100 %. PaT2 and paPD-FS provided precious information enabling an accurate interpretation of the heterogeneous findings of SpA. paPD-FS showed good results in detecting acute and chronic lesions and its inclusion in a routine MR examination of the SIJ could increase the diagnostic performance of a pre-contrast protocol. (orig.)

  8. The diagnostic utility of MRI in spondyloarthritis

    DEFF Research Database (Denmark)

    Pedersen, Susanne J; Weber, Ulrich; Østergaard, Mikkel

    2012-01-01

    The recently developed Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial and peripheral spondyloarthritis (SpA) are the first criteria ever to include findings on magnetic resonance imaging (MRI) of the sacroiliac joints. Features indicating sacroiliac...... joint inflammation on MRI are weighted equally to structural changes on conventional radiography, and thus MRI has become an important tool for use in daily practice to evaluate patients with clinically suspected early spondyloarthritis. However, MRI can also detect structural changes such as erosions...... and fat infiltrations, and recent studies suggest that assessment of both inflammatory and structural changes of the sacroiliac joints may improve the diagnostic utility of MRI. The present article reviews the evidence for the use of sacroiliac joint and spinal MRI to assess patients with axial and...

  9. Imaging in Spondyloarthritis: Controversies in Recognition of Early Disease.

    Science.gov (United States)

    Weber, Ulrich; Jurik, Anne Grethe; Lambert, Robert G W; Maksymowych, Walter P

    2016-09-01

    Advanced imaging has become essential for recognition of clinically suspected early spondyloarthritis. This report summarizes recent progress towards a data-driven comprehensive definition of a positive sacroiliac joint MRI in axial spondyloarthritis, which incorporates contextual information provided by structural lesions alongside with active changes. A focus is on emerging limitations and challenges with increasing use of imaging in spondyloarthritis. We discuss the ongoing controversy as to whether sacroiliac joint MRI due to its superior reliability and ability to depict both structural and active lesions should be the preferred imaging modality in early disease over the traditional approach with pelvic radiographs. Another challenge is transferring the expanding knowledge about imaging evaluation in spondyloarthritis to the community of rheumatologists and radiologists. Advanced imaging modalities will not become the gold standard for diagnosis of spondyloarthritis, which remains a process of composite deduction based on complementary information obtained from clinical, laboratory, and imaging assessment. PMID:27435070

  10. Tumor necrosis factor inhibitor therapy but not standard therapy is associated with resolution of erosion in the sacroiliac joints of patients with axial spondyloarthritis

    OpenAIRE

    Pedersen, Susanne J; Wichuk, Stephanie; Chiowchanwisawakit, Praveena; Lambert, Robert G; Maksymowych, Walter P

    2014-01-01

    Introduction Radiography is an unreliable and insensitive tool for the assessment of structural lesions in the sacroiliac joints (SIJ). Magnetic resonance imaging (MRI) detects a wider spectrum of structural lesions but has undergone minimal validation in prospective studies. The Spondyloarthritis Research Consortium of Canada (SPARCC) MRI Sacroiliac Joint (SIJ) Structural Score (SSS) assesses a spectrum of structural lesions (erosion, fat metaplasia, backfill, ankylosis) and its potential to...

  11. Spondyloarthritis oder Morbus Bechterew: Neue Klassifikation der axialen Spondyloarthritis mit Morbus Bechterew als Endstadium

    OpenAIRE

    Schirmer M; Gander A.

    2011-01-01

    Mit einer Prävalenz von 0,61,9 % ist die axiale Spondyloarthritis (SpA) der Sammelbegriff für eine Gruppe von entzündlichen rheumatischen Krankheiten, die vor allem das axiale Skelett und die Insertionsstellen der Sehnen am Knochen (Enthesen) betreffen. Je nach Subtyp der SpA besteht eine unterschiedlich starke Assoziation mit dem MHC-I-Antigen HLA-B27. Entsprechend der Assessment of Spondyloarthritis International Society (ASAS) wird die SpA anhand der prädominant betroffenen Regio...

  12. Tumor necrosis factor inhibitor therapy but not standard therapy is associated with resolution of erosion in the sacroiliac joints of patients with axial spondyloarthritis

    DEFF Research Database (Denmark)

    Pedersen, Susanne J; Wichuk, Stephanie; Chiowchanwisawakit, Praveena; Lambert, Robert G; Maksymowych, Walter P

    2014-01-01

    INTRODUCTION: Radiography is an unreliable and insensitive tool for the assessment of structural lesions in the sacroiliac joints (SIJ). Magnetic resonance imaging (MRI) detects a wider spectrum of structural lesions but has undergone minimal validation in prospective studies. The Spondyloarthritis...... Research Consortium of Canada (SPARCC) MRI Sacroiliac Joint (SIJ) Structural Score (SSS) assesses a spectrum of structural lesions (erosion, fat metaplasia, backfill, ankylosis) and its potential to discriminate between therapies requires evaluation. METHODS: The SSS score assesses five consecutive coronal...... (ANOVA), discrimination was assessed using Guyatt's effect size, and treatment group differences were assessed using t-tests and the Mann-Whitney test. We identified baseline demographic and structural damage variables associated with change in SSS score by univariate analysis and analyzed the effect of...

  13. Imaging in Spondyloarthritis

    DEFF Research Database (Denmark)

    Weber, Ulrich; Jurik, Anne Grethe; Lambert, Robert G W;

    2016-01-01

    and active lesions should be the preferred imaging modality in early disease over the traditional approach with pelvic radiographs. Another challenge is transferring the expanding knowledge about imaging evaluation in spondyloarthritis to the community of rheumatologists and radiologists. Advanced...

  14. Defining active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis: a consensual approach by the ASAS/OMERACT MRI group

    DEFF Research Database (Denmark)

    Rudwaleit, M; Jurik, A G; Hermann, K-G A;

    2009-01-01

    to reach consensus on which MRI findings are essential for the definition of sacroiliitis. METHODS: Ten doctors (two radiologists and eight rheumatologists) from the ASAS/OMERACT MRI working group reviewed and discussed in three workshops MR images depicting sacroiliitis associated with SpA and other...... relevant for sacroiliitis have been defined by consensus by a group of rheumatologists and radiologists. These definitions should help in applying correctly the imaging feature "active sacroiliitis by MRI" in the new ASAS classification criteria for axial SpA....

  15. Secukinumab: a promising therapeutic option in spondyloarthritis.

    Science.gov (United States)

    Maldonado-Ficco, Hernan; Perez-Alamino, Rodolfo; Maldonado-Cocco, José A

    2016-09-01

    Psoriatic arthritis (PsA) is the second most common chronic inflammatory joint disease. Ankylosing spondylitis (AS) is another less common but equally chronic and disabling spondyloarthritis (SpA). Therapeutic agents for the treatment of these diseases have been somewhat lacking as compared with those available for rheumatoid arthritis, which represents a significant challenge for both the treating physician and the pharmaceutical industry. A promising development for our understanding of the physiopathology of PsA and AS involves new targets to interrupt IL-17 and IL-12/IL-23 pathways. Up to 30-40 % of SpA patients have inadequate or poor response, or are intolerant to anti-TNF therapies. Therefore, there has been a clear unmet medical need in an important group of these patients. As a result, new therapeutic targets have emerged for the treatment of both axial and peripheral SpA. Interleukin 17 (IL-17) is a pro-inflammatory cytokine that is increased in psoriatic lesions as well as in the synovial fluid of patients with PsA and in sites of enthesitis in SpA. IL-23 has been shown to play an important role in the polarization of CD4+ T-cells to become IL-17 producers. Based on these evidences, blockade of the cytokine IL-17 or its receptors was considered to have therapeutic implications for the treatment of psoriasis, as well as PsA and AS.This article presents a thorough review of an IL-17 A blocking agent, its mechanism of action, its clinical efficacy and its therapeutic safety. PMID:27437696

  16. Molecular Pathogenesis of Spondyloarthritis

    DEFF Research Database (Denmark)

    Carlsen, Thomas Gelsing

    This dissertation includes a presentation of knowledge on the molecular pathogenesis of spondyloarthritis achieved through a PhD programme at Aalborg University from 1.12.2011 - 1.12.2014. Work was carried out in the Laboratory of Medical Mass Spectrometry, headed by: Professor Svend Birkelund...... Associate Professor Allan Stensballe The output of this PhD programme, besides from this dissertation, includes 5 published papers, 30 ECTS PhD courses, oral presentations of posters in national and international research environment and a short-term scholarship at the La Jolla Institute for Allergy and...

  17. The FAt Spondyloarthritis Spine Score (FASSS)

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Zhao, Zheng; Lambert, Robert Gw; Wichuk, Stephanie; Østergaard, Mikkel; Weber, Ulrich; Maksymowych, Walter P

    2013-01-01

    Studies have shown that fat lesions follow resolution of inflammation in the spine of patients with axial spondyloarthritis (SpA). Fat lesions at vertebral corners have also been shown to predict development of new syndesmophytes. Therefore, scoring of fat lesions in the spine may constitute both...... an important measure of treatment efficacy as well as a surrogate marker for new bone formation. The aim of this study was to develop and validate a new scoring method for fat lesions in the spine, the Fat SpA Spine Score (FASSS), which in contrast to the existing scoring method addresses the...... localization and phenotypic diversity of fat lesions in patients with axial SpA....

  18. Physical activity in spondyloarthritis: a systematic review

    LENUS (Irish Health Repository)

    O’Dwyer, Tom

    2014-10-01

    Physical activity (PA) is associated with numerous health-related benefits among adults with chronic diseases and the general population. As the benefits are dose-dependent, this review aims to establish the PA levels of adults with spondyloarthritis and to compare these to the general population. Electronic databases (Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE\\/PubMed, PEDro, AMED, CINAHL) were systematically searched from inception to May 2014 using medical subject headings and keywords. This was supplemented by searching conference abstracts and hand-searching reference lists of included studies. Eligible studies were randomized controlled trials and observational studies of adults with SpA in which free-living PA or energy expenditure levels were measured. Subjects less than 18 years or with juvenile-onset SpA were excluded. Outcomes included objective and self-report measurements. Two reviewers independently screened studies for inclusion and assessed methodological quality using the Cochrane risk of bias tool and the RTI item bank. From the 2,431 records reviewed, nine studies involving 2,972 participants were included. This review focused on qualitative synthesis. Meta-analyses were not undertaken due to differences in study design, measurement tools, and participant characteristics. This heterogeneity, coupled with the risk of bias inherent in the included observational studies, limits the generalizability of findings. Objective measurements suggest PA levels may be lower among adults with spondyloarthritis than in healthy population controls. Self-reported PA and self-reported rates of adherence to PA recommendations varied largely across studies; higher disease activity was associated with lower self-reported PA levels. Physical activity levels may be lower in adults with axial spondyloarthritis, with higher disease activity associated with lower PA levels.

  19. Chronic widespread pain in spondyloarthritis

    Directory of Open Access Journals (Sweden)

    F. Atzeni

    2014-06-01

    Full Text Available The pain associated with spondyloarthritis (SpA can be intense, persistent and disabling. It frequently has a multifactorial, simultaneously central and peripheral origin, and may be due to currently active inflammation, or joint damage and tissue destruction arising from a previous inflammatory condition. Inflammatory pain symptoms can be reduced by non-steroidal anti-inflammatory drugs, but many patients continue to experience moderate pain due to alterations in the mechanisms that regulate central pain, as in the case of the chronic widespread pain (CWP that characterises fibromyalgia (FM. The importance of distinguishing SpA and FM is underlined by the fact that SpA is currently treated with costly drugs such as tumour necrosis factor (TNF inhibitors, and direct costs are higher in patients with concomitant CWP or FM than in those with FM or SpA alone. Optimal treatment needs to take into account symptoms such as fatigue, mood, sleep, and the overall quality of life, and is based on the use of tricyclic antidepressants or selective serotonin reuptake inhibitors such as fluoxetine, rather than adjustments in the dose of anti-TNF agents or disease-modifying drugs.

  20. ON THE TERMINOLOGY OF SPONDYLOARTHRITIS

    Directory of Open Access Journals (Sweden)

    Sh. F. Erdes

    2015-01-01

    Full Text Available By the end of the first decade of the 21st century, spondyloarthritis studies have accumulated a certain number of terms that are obsolete, but used by physicians in their everyday speech, on the one hand, and a great variety of different definitions, on the other hand. In January 2014, the first organizational meeting of the Expert Group on Spondyloarthritis, Association of Rheumatologists of Russia, decided that its primary task should be to order the terminology used in this area. The authors primarily collected the terms, which had been already used in medical vocabulary, and then divided them into two categories: obsolete definitions and terms to be finalized and unified. This publication gives guidelines for using the medical terms relevant to spondyloarthritis and separately discusses how to correctly write the term sacroiliitis.

  1. 伴发葡萄膜炎的中轴型脊柱关节炎临床特征分析%Analysis of clinic features of patients with axial spondyloarthritis complicated with uveitis

    Institute of Scientific and Technical Information of China (English)

    陈玉铃; 李挺; 沈洁; 信维伟; 王晓栋; 叶霜

    2016-01-01

    目的:观察中轴型脊柱关节炎伴发葡萄膜炎的发生率,探讨伴发葡萄膜炎的中轴型脊柱关节炎的临床特征。方法收集218例中轴型脊柱关节炎患者,比较葡萄膜炎组与无葡萄膜炎组患者在人口学因素、临床特征、使用药物、生存质量等方面的差异,采用t检验及χ2检验进行统计学分析。结果中轴型脊柱关节炎伴发葡萄膜炎的发生率为24.3%。葡萄膜炎组的病程[(156±140)个月]长于无葡萄膜炎组[(84±98)个月](t=-3.473,P=0.001),起病到确诊时间[(90±105)个月]长于无葡萄膜炎组[(47±65)个月](t=-2.818,P=0.006),就诊到确诊时间[(67±97)个月]长于无葡萄膜炎组[(34±55)个月](t=-2.366,P=0.021),HLA­B27阳性率(97.7%)高于无葡萄膜炎组患者(74.2%)(t=5.822,P=0.016),BASMI得分(3.3±2.0)高于无葡萄膜炎组(2.4±1.9)(t=-3.141,P=0.002),生物制剂使用率(64.2%)高于无葡萄膜炎组患者(46.7%)(t=4.907,P=0.027)。结论在急性前葡萄膜炎患者中应仔细询问病史、及时检测HLA­B27,加强风湿科与眼科会诊制度,以期早期诊治中轴型脊柱关节炎,减少葡萄膜炎的发作及功能受损。%Objective To investigate the prevalence of uveitis associated with axial spondyloarthritis (ax­SpA), and analyze the features of patients with ax­SpA accompanying uveitis. Methods Two hundred and eighteen patients with ax­SpA were recruited. The differences in demographic factors, clinical features, the use of drugs and the quality of life were compared between uveitis group and non­uveitis group by using t­tests andχ2 tests. Results The prevalence of uveitis associated with ax­SpA was 24.3%. Uveitis group had longer disease duration [(156±140) month] compared to the non­uveitis group [(84±98) month] (t=-3.473, P=0.001), longer duration from disease onset to diagnosis [(90±105) month

  2. EULAR RECOMMENDATIONS FOR THE USE OF IMAGING IN SPONDYLOARTHRITIS IN CLINICAL PRACTICE

    DEFF Research Database (Denmark)

    Mandl, P; Navarro-Compán, V; Terslev, L;

    2014-01-01

    Objectives: To develop evidence-based recommendations on the use of imaging in the clinical management of both axial and peripheral spondyloarthritis. Methods: The task force comprised an expert group of 21 rheumatologists, radiologists and methodologists from 11 countries. Twelve key questions on...

  3. Spondyloarthritis oder Morbus Bechterew: Neue Klassifikation der axialen Spondyloarthritis mit Morbus Bechterew als Endstadium

    Directory of Open Access Journals (Sweden)

    Schirmer M

    2011-01-01

    Full Text Available Mit einer Prävalenz von 0,6–1,9 % ist die axiale Spondyloarthritis (SpA der Sammelbegriff für eine Gruppe von entzündlichen rheumatischen Krankheiten, die vor allem das axiale Skelett und die Insertionsstellen der Sehnen am Knochen (Enthesen betreffen. Je nach Subtyp der SpA besteht eine unterschiedlich starke Assoziation mit dem MHC-I-Antigen HLA-B27. Entsprechend der „Assessment of Spondyloarthritis International Society“ (ASAS wird die SpA anhand der prädominant betroffenen Region in die periphere und die axiale Form unterteilt. Die aktuelle Klassifikation der axialen SpA erfolgt mittels der 2009 veröffentlichten ASAS-Kriterien. Bei Sakroiliitis in der Bildgebung müssen ≥ 1 SpAParameter, bei positivem HLA-B27-Befund ≥ 2 andere SpA-Parameter für die Klassifikation als SpA vorhanden sein. SpA-Parameter sind entzündlicher Rückenschmerz, Arthritis, Familienanamnese, Uveitis anterior, entzündliche Darmerkrankung, Psoriasis, Daktylitis, Enthesitis, gutes Ansprechen auf NSAR und HLA-B27-Positivität. Die Sensitivität dieser Kriterien liegt bei 82,9 %, die Spezifität bei 84,4 %. Für die axiale Beteiligung der Psoriasis arthropathica werden auch die ähnlichen CASPAR-Kriterien verwendet. Für die Klassifikation des Morbus Bechterew werden die 1984 modifizierten New York-Kriterien verwendet, bei denen neben spezifischen klinischen Kriterien radiologisch eine Sacroiliitis Grad 2 oder mehr bilateral oder Grad 3–4 unilateral vorhanden sein muss. Bei schwerem Verlauf kann prinzipiell jede Form der SpA mit einer axialen Beteiligung in einen Morbus Bechterew übergehen. Somit ist der Morbus Bechterew sowohl ein Subtyp der SpA, als auch eine mögliche Spätform anderer Subtypen. Zur Verlaufs- bzw. Therapiekontrolle werden sowohl bei axialer SpA als auch bei Morbus Bechterew spezifische Scores verwendet, um Krankheitsaktivität und Funktionsveränderungen zu dokumentieren (BASFI, BASDAI, ASDAS.

  4. Axial location of cladding failure during a slow transient overpower TREAT test

    International Nuclear Information System (INIS)

    The axial location of cladding failure following a transient overpower accident is of importance in fast reactor safety studies in that it is a determining factor in the relocation of fuel, and therefore in the possibility of inherent neutronic shutdown of the reactor. In-pile experimental data on the axial location of cladding failure of fuel in bundles of pins is sparse since, in general, the experimental fuel pin bundles are largely destroyed during the in-pile test. The post-test examination work has been completed for TREAT test J1. It was found that damage to the fuel elements during the irradiation was low enough for an accurate observation of the location of cladding failure to be made for each of the seven pins

  5. Gut inflammation and microbiome in spondyloarthritis.

    Science.gov (United States)

    Kabeerdoss, Jayakanthan; Sandhya, Pulukool; Danda, Debashish

    2016-04-01

    Spondyloarthritis (SpA) is chronic inflammatory disease involving joints and the spine. Bowel inflammation is common in SpA, which may be classified as acute or chronic. Chronic gut inflammation is most common in SpA patients with axial involvement as compared to those presenting with peripheral involvement alone. The pathogenesis of gut inflammation in SpA could be explained by two factors-over-activation of immunological cells and altered gut microbiome. This is exemplified by SpA animal models, namely HLA-B27-expressing transgenic animals and SKG mice models. Immunological mechanisms include homing of activated T cells from gut into synovium, excess pro-inflammatory cytokines secretion by immune cells such as IL-23 and genetic variations in immunological genes. The evidence for role of gut microbiome in SpA is gradually emerging. Recently, metagenomic study of gut microbiome by sequencing of microbial nucleic acids has enabled identification of new microbial taxa and their functions in gut of patients with SpA. In SpA, the gut microbiome could emerge as diagnostic and prognostic marker of disease. Modulation of gut microbiome is slated to have therapeutic potential as well. PMID:26719306

  6. EULAR recommendations for the use of imaging in the diagnosis and management of spondyloarthritis in clinical practice

    DEFF Research Database (Denmark)

    Mandl, P; Navarro-Compán, V; Terslev, L;

    2015-01-01

    A taskforce comprised of an expert group of 21 rheumatologists, radiologists and methodologists from 11 countries developed evidence-based recommendations on the use of imaging in the clinical management of both axial and peripheral spondyloarthritis (SpA). Twelve key questions on the role of...... produce recommendations that are practical and valuable in daily practice for rheumatologists, radiologists and general practitioners....

  7. Revisiting MHC genes in spondyloarthritis.

    Science.gov (United States)

    Breban, Maxime; Costantino, Félicie; André, Claudine; Chiocchia, Gilles; Garchon, Henri-Jean

    2015-06-01

    Spondyloarthritis (SpA) refers to a variety of inflammatory rheumatic disorders with strong heritability. Shared genetic predisposition, as shown by familial aggregation, is largely attributable to the major histocompatibility complex (MHC) locus, which was estimated to account for approximately half of the whole disease heritability. The first predisposing allele identified more than 40 years ago is HLA-B27, which is a major gene predisposing to all forms of SpA. However, despite intensive research, its pathogenesis remains uncertain. Other MHC alleles belonging to the class I and class II regions have been identified to exert additional effect. Candidate-gene approaches and genome-wide studies have recently allowed identification of several new loci residing outside of the MHC region that are involved in the predisposition to SpA. Interestingly, some of those new genes, such as ERAP1, ERAP2, and NPEPPS, code for aminopeptidases that are involved in MHC class I presentation and were shown to interact with HLA-B27. PMID:25903667

  8. Defining enthesitis in spondyloarthritis by ultrasound

    DEFF Research Database (Denmark)

    Terslev, Lene; Naredo, E; Iagnocco, A;

    2014-01-01

    Objective: To standardize ultrasound (US) in enthesitis. Methods: An Initial Delphi exercise was undertaken to define US detected enthesitis and its core components. These definitions were subsequently tested on static images taken from Spondyloarthritis (SpA) patients in order to evaluate their ...

  9. Uveitis in Spondyloarthritis: An Overview.

    Science.gov (United States)

    Cantini, Fabrizio; Nannini, Carlotta; Cassarà, Emanuele; Kaloudi, Olga; Niccoli, Laura

    2015-11-01

    Autoimmune anterior uveitis (AU) accounts for at least half of the cases of noninfectious uveitis, and similarly to spondyloarthritis (SpA), its occurrence is related to HLA-B27 positivity. AU is significantly more frequently found in HLA-B27-positive subjects with SpA and is characterized by unilateral eye involvement, marked tendency to recur with involvement of both eyes in alternate fashion, and has good prognosis in the majority of cases. The estimated frequency of SpA in patients with AU is around 50%, whereas AU in SpA has been reported in at least 30% of cases. Across the SpA disease spectrum, AU has a frequency peak of 33.4% in patients with ankylosing spondylitis, while the estimated prevalence in psoriatic arthritis (PsA) and inflammatory bowel disease-associated SpA is 2%-25%, and 25%, respectively. In early PsA, the frequency of AU has been found in 9% of patients. The wide range of prevalence reported in PsA may be explained by the variable sets of classification criteria used for patient selection and the different length of followup. AU may precede the clinical features of SpA, may be present at diagnosis, or may complicate the SpA clinical course. However, the occurrence of AU in SpA as well as AU flares has been reduced through treatment of SpA with anti-tumor necrosis factor-α agents. PMID:26523051

  10. Associations between spondyloarthritis features and MRI findings

    DEFF Research Database (Denmark)

    Arnbak, Bodil; Jurik, Anne Grethe; Hørslev-Petersen, Kim;

    2015-01-01

    ASAS definition, was present in 217(21%) patients. Of those, 91(42%) had bone marrow oedema (BMO) at the minimum requirement according to ASAS (low BMO score). HLA-B27, peripheral arthritis, good response to NSAID, and preceding infection associated independently with SIJ MRI findings (OR range 1...... clinical features and MRI findings included in ASAS criteria, and 2) explore the associations between clinical features and MRI findings. METHODS: Patients aged 18-40 years with persistent LBP referred to an outpatient spine clinic were included. Information on clinical features (incl. HLA-B27 and CRP) and......OBJECTIVES: The Assessment of SpondyloArthritis international Society (ASAS) has previously published criteria for spondyloarthritis (SpA). The objectives in the current study were in a low back pain (LBP) cohort, including an unknown proportion of SpA patients, to: 1) estimate the prevalence of...

  11. Molecular mechanisms of bone formation in spondyloarthritis.

    Science.gov (United States)

    González-Chávez, Susana Aideé; Quiñonez-Flores, Celia María; Pacheco-Tena, César

    2016-07-01

    Spondyloarthritis comprise a group of inflammatory rheumatic diseases characterized by its association to HLA-B27 and the presence of arthritis and enthesitis. The pathogenesis involves both an inflammatory process and new bone formation, which eventually lead to ankylosis of the spine. To date, the intrinsic mechanisms of the pathogenic process have not been fully elucidated, and our progress is remarkable in the identification of therapeutic targets to achieve the control of the inflammatory process, yet our ability to inhibit the excessive bone formation is still insufficient. The study of new bone formation in spondyloarthritis has been mostly conducted in animal models of the disease and only few experiments have been done using human biopsies. The deregulation and overexpression of molecules involved in the osteogenesis process have been observed in bone cells, mesenchymal cells, and fibroblasts. The signaling associated to the excessive bone formation is congruent with those involved in the physiological processes of bone remodeling. Bone morphogenetic proteins and Wnt pathways have been found deregulated in this disease; however, the cause for uncontrolled stimulation remains unknown. Mechanical stress appears to play an important role in the pathological osteogenesis process; nevertheless, the association of other important factors, such as the presence of HLA-B27 and environmental factors, remains uncertain. The present review summarizes the experimental findings that describe the signaling pathways involved in the new bone formation process in spondyloarthritis in animal models and in human biopsies. The role of mechanical stress as the trigger of these pathways is also reviewed. PMID:26838262

  12. Coexisting HLA-B27 positive spondyloarthritis and polyarteritis nodosa.

    OpenAIRE

    Sattar, M A

    1992-01-01

    A 38 year old woman presented with widespread polyarteritis nodosa a few years after the onset of HLA-B27 positive spondyloarthritis. The concomitant coexistence of these two disorders suggests a possible association in this genetically susceptible subject.

  13. Decreased plasma levels of soluble CD18 link leukocyte infiltration with disease activity in spondyloarthritis

    DEFF Research Database (Denmark)

    Kragstrup, Tue Wenzel; Jalilian, Babak; Hvid, Malene;

    2014-01-01

    A patients compared with healthy volunteers (P < 0.001) with the lowest levels in the HLA-B27-positive subgroup (P < 0.05). In a multiple regression model the sCD18 levels exhibited an inverse correlation with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (P < 0.05), the level of morning......INTRODUCTION: Spondyloarthritis (SpA) comprises a group of diseases often associated with HLA-B27 and characterized by inflammation of the entheses and joints of the axial skeleton. The inflammatory process in SpA is presumably driven by innate immune cells but still poorly understood. Thus, new...... of arthritis patients to have anti-inflammatory functions. Here, we study the mechanisms for these alterations and their association with SpA disease activity. METHODS: Plasma levels of sCD18 in a study population with 84 SpA patients and matched healthy controls were analyzed with a time resolved...

  14. Occult spondyloarthritis in inflammatory bowel disease.

    Science.gov (United States)

    Bandinelli, Francesca; Manetti, Mirko; Ibba-Manneschi, Lidia

    2016-02-01

    Spondyloarthritis (SpA) is a frequent extra-intestinal manifestation in patients with inflammatory bowel disease (IBD), although its real diffusion is commonly considered underestimated. Abnormalities in the microbioma and genetic predisposition have been implicated in the link between bowel and joint inflammation. Otherwise, up to date, pathogenetic mechanisms are still largely unknown and the exact influence of the bowel activity on rheumatic manifestations is not clearly explained. Due to evidence-based results of clinical studies, the interest on clinically asymptomatic SpA in IBD patients increased in the last few years. Actually, occult enthesitis and sacroiliitis are discovered in high percentages of IBD patients by different imaging techniques, mainly enthesis ultrasound (US) and sacroiliac joint X-ray examinations. Several diagnostic approaches and biomarkers have been proposed in an attempt to correctly classify and diagnose clinically occult joint manifestations and to define clusters of risk for patient screening, although definitive results are still lacking. The correct recognition of occult SpA in IBD requires an integrated multidisciplinary approach in order to identify common diagnostic and therapeutic strategies. The use of inexpensive and rapid imaging techniques, such as US and X-ray, should be routinely included in daily clinical practice and trials to correctly evaluate occult SpA, thus preventing future disability and worsening of quality of life in IBD patients. PMID:26354428

  15. Limited role of gadolinium to detect active sacroiliitis on MRI in juvenile spondyloarthritis

    Energy Technology Data Exchange (ETDEWEB)

    Herregods, N.; Leus, A.; Verstraete, K.; Jans, L. [Ghent University Hospital, Department of Radiology and Medical Imaging, Ghent (Belgium); Jaremko, J.L. [University of Alberta Hospital, Department of Radiology and Diagnostic Imaging, Edmonton, AB (Canada); Baraliakos, X. [Ruhr-University Bochum, Rheumazentrum Ruhrgebiet, Herne (Germany); Dehoorne, J. [Ghent University Hospital, Department of Pediatric Rheumatology, Ghent (Belgium)

    2015-11-15

    The aim of this study is to determine the added diagnostic value of contrast-enhanced (CE) magnetic resonance imaging (MRI) compared to routine non contrast-enhanced MRI to detect active sacroiliitis in clinically juvenile spondyloarthritis (JSpA). A total of 80 children clinically suspected for sacroiliitis prospectively underwent MRI of the sacroiliac (SI) joints. Axial and coronal T1-weighted (T1), Short-tau inversion recovery (STIR) and fat-saturated T1-weighted gadolinium-DTPA (Gd) contrast-enhanced (T1/Gd) sequences were obtained. The presence of bone marrow edema (BME), capsulitis, enthesitis, high intra-articular STIR signal, synovial enhancement and a global diagnostic impression of the MRI for diagnosis of sacroiliitis was recorded. STIR and T1/Gd sequences had 100 % agreement for depiction of BME, capsulitis and enthesitis. High intra-articular STIR signal was seen in 18/80 (22.5 %) patients, 15 (83 %) of whom also showed synovial enhancement in the T1/Gd sequence. Sensitivity (SN) and specificity (SP) for a clinical diagnosis of JSpA were similar for high STIR signal (SN = 33 %, SP = 85 %) and T1/Gd synovial enhancement (SN = 36 %, SP = 92 %). Positive likelihood ratio (LR+) for JSpA was twice as high for synovial enhancement than high STIR signal (4.5 compared to 2.2). Global diagnostic impression was similar (STIR: SN = 55 %, SP = 87 %, LR + =4.2; T1/Gd: SN = 55 %, SP = 92 %, LR + = 6.9). MRI without contrast administration is sufficient to identify bone marrow edema, capsulitis and retroarticular enthesitis as features of active sacroiliitis in juvenile spondyloarthritis. In selected cases when high STIR signal in the joint is the only finding, gadolinium-enhanced images may help to confirm the presence of synovitis. (orig.)

  16. Analysis and performance of various classification criteria sets in a Colombian cohort of patients with spondyloarthritis.

    Science.gov (United States)

    Bautista-Molano, Wilson; Landewé, Robert B M; Londoño, John; Romero-Sanchez, Consuelo; Valle-Oñate, Rafael; van der Heijde, Désirée

    2016-07-01

    The objective of this study was to investigate the performance of classification criteria sets (Assessment of SpondyloArthritis international Society (ASAS), European Spondylarthropathy Study Group (ESSG), and Amor) for spondyloarthritis (SpA) in a clinical practice cohort in Colombia and provide insight into how rheumatologists follow the diagnostic path in patients suspected of SpA. Patients with a rheumatologist's diagnosis of SpA were retrospectively classified according to three criteria sets. Classification rate was defined as the proportion of patients fulfilling a particular criterion. Characteristics of patients fulfilling and not fulfilling each criterion were compared. The ASAS criteria classified 81 % of all patients (n = 581) as having either axial SpA (44 %) or peripheral SpA (37 %), whereas a lower proportion met ESSG criteria (74 %) and Amor criteria (53 %). There was a high degree of overlap among the different criteria, and 42 % of the patients met all three criteria. Patients fulfilling all three criteria sets were older (36 vs. 30 years), had more SpA features (3 vs. 1 features), and more frequently had a current or past history of back pain (77 vs. 43 %), inflammatory back pain (47 vs. 13 %), enthesitis (67 vs. 26 %), and buttock pain (37 vs. 13 %) vs. those not fulfilling any criteria. HLA-B27, radiographs, and MRI-SI were performed in 77, 59, and 24 % of the patients, respectively. The ASAS criteria classified more patients as having SpA in this Colombian cohort when the rheumatologist's diagnosis is used as an external standard. Although physicians do not perform HLA-B27 or imaging in all patients, they do require these tests if the clinical symptoms fall short of confirming SpA and suspicion remains. PMID:26791876

  17. Limited role of gadolinium to detect active sacroiliitis on MRI in juvenile spondyloarthritis

    International Nuclear Information System (INIS)

    The aim of this study is to determine the added diagnostic value of contrast-enhanced (CE) magnetic resonance imaging (MRI) compared to routine non contrast-enhanced MRI to detect active sacroiliitis in clinically juvenile spondyloarthritis (JSpA). A total of 80 children clinically suspected for sacroiliitis prospectively underwent MRI of the sacroiliac (SI) joints. Axial and coronal T1-weighted (T1), Short-tau inversion recovery (STIR) and fat-saturated T1-weighted gadolinium-DTPA (Gd) contrast-enhanced (T1/Gd) sequences were obtained. The presence of bone marrow edema (BME), capsulitis, enthesitis, high intra-articular STIR signal, synovial enhancement and a global diagnostic impression of the MRI for diagnosis of sacroiliitis was recorded. STIR and T1/Gd sequences had 100 % agreement for depiction of BME, capsulitis and enthesitis. High intra-articular STIR signal was seen in 18/80 (22.5 %) patients, 15 (83 %) of whom also showed synovial enhancement in the T1/Gd sequence. Sensitivity (SN) and specificity (SP) for a clinical diagnosis of JSpA were similar for high STIR signal (SN = 33 %, SP = 85 %) and T1/Gd synovial enhancement (SN = 36 %, SP = 92 %). Positive likelihood ratio (LR+) for JSpA was twice as high for synovial enhancement than high STIR signal (4.5 compared to 2.2). Global diagnostic impression was similar (STIR: SN = 55 %, SP = 87 %, LR + =4.2; T1/Gd: SN = 55 %, SP = 92 %, LR + = 6.9). MRI without contrast administration is sufficient to identify bone marrow edema, capsulitis and retroarticular enthesitis as features of active sacroiliitis in juvenile spondyloarthritis. In selected cases when high STIR signal in the joint is the only finding, gadolinium-enhanced images may help to confirm the presence of synovitis. (orig.)

  18. Ankylosing spondyloarthritis in the rheumatology practice of Karelia

    OpenAIRE

    Irina Mikhailovna Marusenko; A A Brazhnik; N N Vezikova; O A Vaskova

    2012-01-01

    The paper describes the pathological aspects of an inflammatory process in ankylosing spondyloarthritis (AS), the role of muscle spasm in maintaining the intensity of pain syndrome and stiffness, the need for the early diagnosis of AS, and the significance of the early use of nonster-oidal anti-inflammatory drugs in these patients. The results of clinical trials and the authorsX data demonstrate the high efficacy and good tolerance of nimesulide (nise) in AS.

  19. Ankylosing spondyloarthritis in the rheumatology practice of Karelia

    Directory of Open Access Journals (Sweden)

    Irina Mikhailovna Marusenko

    2012-12-01

    Full Text Available The paper describes the pathological aspects of an inflammatory process in ankylosing spondyloarthritis (AS, the role of muscle spasm in maintaining the intensity of pain syndrome and stiffness, the need for the early diagnosis of AS, and the significance of the early use of nonster-oidal anti-inflammatory drugs in these patients. The results of clinical trials and the authorsX data demonstrate the high efficacy and good tolerance of nimesulide (nise in AS.

  20. Ankylosing spondyloarthritis in the rheumatology practice of Karelia

    Directory of Open Access Journals (Sweden)

    Irina Mikhailovna Marusenko

    2012-01-01

    Full Text Available The paper describes the pathological aspects of an inflammatory process in ankylosing spondyloarthritis (AS, the role of muscle spasm in maintaining the intensity of pain syndrome and stiffness, the need for the early diagnosis of AS, and the significance of the early use of nonster-oidal anti-inflammatory drugs in these patients. The results of clinical trials and the authorsX data demonstrate the high efficacy and good tolerance of nimesulide (nise in AS.

  1. Towards new measures of inflammation in spondyloarthritis

    OpenAIRE

    Baeten, D. L. P.; Landewé, R.B.M.; Turina, M.C.

    2016-01-01

    Spondyloartritis is een vorm van chronische gewrichtsontsteking welke zowel het axiale skelet als de perifere gewrichten aantast. Het is hierbij belangrijk om de periode tussen symptomen en het stellen van de diagnose van 5-10 jaar te vervroegen. In dit proefschrift is aangetoond dat potentieel interessante inflammatoire serum biomarkers hieraan niet kunnen bijdragen. Wel lijkt het opzetten van een inceptie-cohort van eerstegraads familieleden van HLA-B27 positieve spondylitis ankylopoetica p...

  2. Magnetic resonance imaging of sacroiliitis in patients with spondyloarthritis. Correlation with anatomy and histology

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, K.G.A. [Charite Medical School, Campus Mitte, Berlin (Germany). Dept. of Radiology; Bollow, M. [Augusta Hospital, Bochum (Germany). Dept. of Diagnostic and Interventional Radiology and Nuclear Medicine

    2014-03-15

    Magnetic resonance imaging (MRI) of the sacroiliac joints (SIJs) has become established as a valuable modality for the early diagnosis of sacroiliitis in patients with inconclusive radiographic findings. Positive MRI findings have the same significance as a positive test for HLA-B27. Sacroiliitis is one of the key features of axial spondyloarthritis (SpA) in the classification proposed by the Assessments in Ankylosing Spondylitis (ASAS) group. Early signs of sacroiliitis include enthesitis of articular fibrocartilage, capsulitis, and osteitis. In more advanced disease, structural (chronic) lesions will be visible, including periarticular fatty deposition, erosions, subchondral sclerosis, and transarticular bone buds and bridges. In this article we describe magnetic resonance (MR) findings and provide histologic biopsy specimens of the respective disease stages. The predominant histologic feature of early and active sacroiliitis is the destruction of cartilage and bone by proliferations consisting of fibroblasts and fibrocytes, T-cells, and macrophages. Advanced sacroiliitis is characterized by new bone formation with enclosed cartilaginous islands and residual cellular infiltrations, which may ultimately lead to complete ankylosis. Knowledge of the morphologic appearance of the sacroiliac joints and their abnormal microscopic and gross anatomy is helpful in correctly interpreting MR findings. (orig.)

  3. Development and validation of an MRI reference criterion for defining a positive SIJ MRI in spondyloarthritis

    DEFF Research Database (Denmark)

    Weber, Ulrich; Zubler, Veronika; Pedersen, Susanne J; Rufibach, Kaspar; Lambert, Robert G W; Chan, Stanley M; Østergaard, Mikkel; Maksymowych, Walter P

    2012-01-01

    OBJECTIVE: To validate an MRI reference criterion for a positive SIJ MRI based on the level of confidence in classification of spondyloarthritis (SpA) by expert MRI readers. METHODS: Four readers assessed SIJ MRI in two inception cohorts (A/B) of 157 consecutive back pain patients ≤50 years, and in...... 20 healthy controls. Patients were classified according to clinical examination and pelvic radiography as having non-radiographic axial SpA (n=51), ankylosing spondylitis (n=34), or non-specific back pain (n=72). Readers recorded their level of confidence in the classification of SpA on a 0-10 scale...... (0=definitely not; 10=definite). The MRI reference criterion was pre-specified as the majority of readers recording a confidence of 8-10; absence of SpA required all readers to record Non-SpA (confidence 0-4). We calculated inter-reader reliability and agreement between MRI-based and clinical...

  4. Danish recommendations on treatment of ankylosing spondylitis and spondyloarthritis based on multinational project initiative

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Madsen, Ole Rintek; Erlendsson, J.; Schiottz-Christensen, B.; Sørensen, Inge Juul; Andersen, L.S.; Østergaard, Morten

    2008-01-01

    INTRODUCTION: The multinational initiative "3e Initiative in Rheumatology - Multi-national Recommendations for the Management of Ankylosing Spondylitis 2006-7" served the primary purpose of providing specific recommendations for the management of ankylosing spondylitis and spondyloarthritis...

  5. Cartilage collagen type II seromarker patterns in axial spondyloarthritis and psoriatic arthritis

    DEFF Research Database (Denmark)

    Munk, Heidi Lausten; Gudmann, Natasja Staehr; Christensen, Anne Friesgaard;

    2016-01-01

    disease activity measures and HLA-B27 typing. The procollagen IIA N-terminal peptide (PIIANP) and a matrix metalloproteinase-generated type II collagen fragment (C2M) were quantified in serum by ELISA. C2M was higher in SpA than in controls, 0.41 versus 0.36 ng/ml (p = 0.004), while PIIANP did not differ......-smokers, 0.43 ng/ml (p = 0.02), while PIIANP was higher in HLA-B27 positive, 2312 ng/ml versus negative patients, 2021 ng/ml (p = 0.03). In PsA, PIIANP and C2M did not differ between patients and controls, but PIIANP was elevated in patients not receiving DMARDs, 2726 ng/ml. In PsA, PIIANP and C2M did not...... differ according to smoking and HLA-B27. Cartilage degradation assessed by C2M is increased in SpA irrespective of treatment but not in PsA. Cartilage synthesis reflected by PIIANP is increased in untreated SpA and PsA. PIIANP correlates with CRP in SpA while not in PsA. In DMARD-naïve SpA but not in Ps...

  6. Does evaluation of the ligamentous compartment enhance diagnostic utility of sacroiliac joint MRI in axial spondyloarthritis?

    DEFF Research Database (Denmark)

    Weber, Ulrich; Maksymowych, Walter P; Chan, Stanley M;

    2015-01-01

    compartment alone. METHODS: Two independent cohorts of 69 and 88 consecutive back pain patients ≤50 years were referred for suspected SpA (cohort A) or acute anterior uveitis plus back pain (cohort B). Patients were classified according to rheumatologist expert opinion based on clinical, radiographic and...

  7. A UK Best Practice Model for Diagnosis and Treatment of Axial Spondyloarthritis

    OpenAIRE

    Rebecca Adshead; Hasan Tahir; Simon Donnelly

    2015-01-01

    Objectives: To examine the combined effectiveness of a care pathway for patients with suspected inflammatory back pain (IBP) in conjunction with an educational campaign targeting primary and secondary care and the local community. Methods: Between June 2010 and June 2013, general practitioners referred patients fulfilling the Berlin IBP criteria into our Early Inflammatory Back Pain Service (EIBPS). Investigations were undertaken in line with our service model pathway and consultant rheuma...

  8. MODERN IDEA ON THE PATHOGENESIS OF SPONDYLOARTHRITIS: MOLECULAR MECHANISMS

    Directory of Open Access Journals (Sweden)

    E. L. Nasonov

    2015-09-01

    Full Text Available As of now, impaired immune homeostasis of the intestinal mucosa in genetically predisposed individuals is considered to be one of the major components in the pathogenesis of spondyloarthritis (SpA, which leads to systemic chronic inflammation. The results of recent studies may suggest that the interleukin-23/interleukin-17 (IL-23/IL-17 axis plays a leading role in the development of these diseases. The multifactorial components of the pathogenesis of SpA are characterized by not only the hyperproduction of IL-23, but also by the change in cell target susceptibility to this cytokine with aconcurrent increase in their number, resulting in the chronic autoinflammatory process that occurs via a wide spectrum of clinical manifestations of different types of SpA

  9. MR enterography to evaluate sub-clinical intestinal inflammation in children with spondyloarthritis

    Directory of Open Access Journals (Sweden)

    Stoll Matthew L

    2012-02-01

    Full Text Available Abstract Background Magnetic resonance enterography (MRE is an established tool to evaluate for changes associated with inflammatory bowel disease (IBD, but has not been studied in sub-clinical IBD. We sought to evaluate the use of MRE in children with spondyloarthritis (SpA, who are at risk of having sub-clinical gut inflammation. Methods Children with juvenile idiopathic arthritis (JIA with evidence of intestinal inflammation as evidence by an abnormal fecal calprotectin assay were offered MRE of their intestines. Flavored sports drink containing polyethylene glycol 3350 was used as oral contrast. Glucagon was used to arrest peristalsis. Patients were imaged in the prone position on a 1.5 T scanner. Heavily T2-weighted fat-suppressed coronal and axial images using breath-hold technique were obtained, followed by post-gadolinium fat-suppressed T1-weighted gradient echo images. Results We recruited five children with juvenile idiopathic arthritis (JIA; four had SpA, and one had poly-articular JIA. All five had evidence of intestinal inflammation based upon a positive fecal calprotectin assay and successfully completed the MRE. Three of the studies showed findings suggestive of IBD, including thickening and contrast uptake at the terminal ileum (TI in one child, contrast uptake of the distal ileum in another, and prominent vasa recta and mesenteric lymph nodes in the third. The child with evidence of inflammatory changes at the TI underwent colonoscopy, which revealed inflammatory bowel disease limited to the TI. Conclusions MRE can be used to evaluate for subclinical IBD in children with JIA. This protocol was safe and well-tolerated, and identified mild changes in three of the subjects.

  10. The -308 TNFα and the -174 IL-6 promoter polymorphisms associate with effective anti-TNFα treatment in seronegative spondyloarthritis.

    Science.gov (United States)

    Fabris, M; Quartuccio, L; Fabro, C; Sacco, S; Lombardi, S; Ramonda, R; Biasi, D; Punzi, D; Adami, S; Olivieri, I; Curcio, F; De Vita, S

    2016-06-01

    The genetic predisposition to a long-term efficacy of anti-tumor necrosis factor (TNF)α treatment in seronegative spondyloarthritis (SpA) was investigated by analysing the possible correlation between several single nucleotide gene polymorphisms and the retention rate of anti-TNFα therapies. We compared patients needing to switch the first anti-TNFα (Sw, No. 64) within at least 12 months of follow-up with patients not needing to switch (NSw, No. 123), observing at least 6 months of treatment to establish anti-TNFα failure, leading to treatment change. Response to treatment was evaluated by standardised criteria (BASDAI for axial involvement, DAS28-EULAR for peripheral involvement). The TNFα -308 A allele and the interleukin (IL)-6 -174GG homozygosis resulted as independent biomarkers predicting survival of the first anti-TNFα therapy in SpA patients (P=0.007, odds ratio (OR): 4.4, 95% confidence interval (CI)=1.5-13.1 and P=0.035, OR: 2.1, 95% CI=1.1-4.4). Also, the male gender (P=0.001, OR: 3.4, 95% CI=1.6-7.1) associated with the NSw phenotype, whereas no association was found either with the specific diagnosis or the predominant joint involvement. PMID:26149736

  11. Validity of ankylosing spondylitis and undifferentiated spondyloarthritis diagnoses in the Swedish National Patient Register

    DEFF Research Database (Denmark)

    Lindström, U; Exarchou, S; Sigurdardottir, V; Sundström, B; Askling, J; Eriksson, J K; Forsblad-d'Elia, H; Turesson, C; Kristensen, L E; Jacobsson, L

    2015-01-01

    OBJECTIVES: Epidemiological studies of spondyloarthritis (SpA), using ICD codes from the Swedish National Patient Register (NPR), offer unique possibilities but hinge upon an understanding of the validity of the codes. The aim of this study was to validate the ICD codes for ankylosing spondylitis...

  12. Whole-body MRI of juvenile spondyloarthritis: protocols and pictorial review of characteristic patterns

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Michael R. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Tse, Shirley M.L.; Rachlis, Alisa C. [Hospital for Sick Children, Department of Rheumatology, Toronto (Canada); Gupta, Sumeet; Stimec, Jennifer [Hospital for Sick Children, Department of Radiology, Toronto (Canada)

    2015-05-01

    Spondyloarthritides are a group of inflammatory rheumatological diseases that cause arthritis with a predilection for spinal or sacroiliac involvement in addition to a high association with HLA-B27. Juvenile spondyloarthritis is distinct from adult spondyloarthritis and manifests more frequently as peripheral arthritis and enthesitis. Consequently juvenile spondyloarthritis is often referred to as enthesitis-related arthritis (ERA) subtype under the juvenile idiopathic arthritis (JIA) classification criteria. The American College of Rheumatology Treatment Recommendations for JIA, including ERA, are based on the following clinical parameters: current treatment, disease activity and the presence of poor prognostic features. The MRI features of juvenile spondyloarthritis include marrow edema, peri-enthesal soft-tissue swelling and edema, synovitis and joint or bursal fluid. Marrow edema is nonspecific and can be seen with other pathologies as well as in healthy subjects, and this is an important pitfall to consider. With further longitudinal study and validation, however, whole-body MRI with dedicated images of the more commonly affected areas such as the spine, sacroiliac joints, hips, knees, ankles and feet can serve as a more objective tool compared to clinical exam for early detection and monitoring of disease activity and ultimately direct therapeutic management. (orig.)

  13. Fears and beliefs in rheumatoid arthritis and spondyloarthritis: a qualitative study.

    Directory of Open Access Journals (Sweden)

    Francis Berenbaum

    Full Text Available To explore beliefs and apprehensions about disease and its treatment in patients with rheumatoid arthritis and spondyloarthritis.25 patients with rheumatoid arthritis and 25 with spondyloarthritis participated in semi-structured interviews about their disease and its treatment. The interviews were performed by trained interviewers in participants' homes. The interviews were recorded and the main themes identified by content analysis.Patients differentiated between the underlying cause of the disease, which was most frequently identified as a hereditary or individual predisposition. In patients with rheumatoid arthritis, the most frequently cited triggering factor for disease onset was a psychological factor or life-event, whereas patients with spondyloarthritis tended to focus more on an intrinsic vulnerability to disease. Stress and overexertion were considered important triggering factors for exacerbations, and relaxation techniques were frequently cited strategies to manage exacerbations. The unpredictability of the disease course was a common source of anxiety. Beliefs about the disease and apprehensions about the future tended to evolve over the course of the disease, as did treatment expectations.Patients with rheumatoid arthritis and spondyloarthritis hold a core set of beliefs and apprehensions that reflect their level of information about their disease and are not necessarily appropriate. The physician can initiate discussion of these beliefs in order to dispel misconceptions, align treatment expectations, provide reassurance to the patient and readjust disease management. Such a dialogue would help improve standards of care in these chronic and incapacitating diseases.

  14. Functional variants of ERAP1 gene are associated with HLA-B27 positive spondyloarthritis.

    Science.gov (United States)

    Cherciu, M; Popa, L O; Bojinca, M; Dutescu, M I; Bojinca, V; Bara, C; Popa, O M

    2013-09-01

    We investigated two nonsynonymous variants (rs30187 and rs27044) of ERAP1 gene in HLA-B27 positive individuals (150 spondyloarthritis and 108 controls) and in general ankylosing spondylitis (AS) patients (n = 137) vs random controls (n = 139). Both single nucleotide polymorphisms (SNPs) were associated with the risk of spondyloarthritis [odds ratio (OR) 1.80, 95% confidence interval (CI) 1.24-2.62, P = 0.001 for rs30187, OR 1.58, 95% CI 1.07-2.34, P = 0.02 for rs27044]. The CC haplotype was a protective factor (P = 0.002), while the TG haplotype was a risk factor (P = 0.01) for spondyloarthritis. The SNP rs30187 was also associated with the risk of HLA-B27+ AS. For the general group of AS, the carriers of minor alleles showed an increased risk for the disease (OR 1.92, 95% CI 1.17-3.13 for rs30187, OR 1.74, 95% CI 1.08-2.80 for rs27044). This is the first study that shows the association of ERAP1 gene variants and haplotypes with HLA-B27 positive spondyloarthritis. PMID:23800305

  15. Whole-body MRI of juvenile spondyloarthritis: protocols and pictorial review of characteristic patterns

    International Nuclear Information System (INIS)

    Spondyloarthritides are a group of inflammatory rheumatological diseases that cause arthritis with a predilection for spinal or sacroiliac involvement in addition to a high association with HLA-B27. Juvenile spondyloarthritis is distinct from adult spondyloarthritis and manifests more frequently as peripheral arthritis and enthesitis. Consequently juvenile spondyloarthritis is often referred to as enthesitis-related arthritis (ERA) subtype under the juvenile idiopathic arthritis (JIA) classification criteria. The American College of Rheumatology Treatment Recommendations for JIA, including ERA, are based on the following clinical parameters: current treatment, disease activity and the presence of poor prognostic features. The MRI features of juvenile spondyloarthritis include marrow edema, peri-enthesal soft-tissue swelling and edema, synovitis and joint or bursal fluid. Marrow edema is nonspecific and can be seen with other pathologies as well as in healthy subjects, and this is an important pitfall to consider. With further longitudinal study and validation, however, whole-body MRI with dedicated images of the more commonly affected areas such as the spine, sacroiliac joints, hips, knees, ankles and feet can serve as a more objective tool compared to clinical exam for early detection and monitoring of disease activity and ultimately direct therapeutic management. (orig.)

  16. Acute Anterior Uveitis and Spondyloarthritis: More Than Meets the Eye.

    Science.gov (United States)

    Khan, Muhammad A; Haroon, Muhammad; Rosenbaum, James T

    2015-09-01

    Ankylosing spondylitis (AS) and related forms of spondyloarthritis (SpA) are associated with some extra-articular features, and the most common symptomatic association is with acute anterior uveitis (AAU). Thus, approximately 40 % of patients with AS will experience a sudden onset of a unilateral anterior uveitis sometime during the course of their disease. Patients with AAU, especially those who are HLA-B27 positive, should be questioned about inflammatory low back pain and also evaluated for other clinical features of SpA. Since a prolonged delay in diagnosis is common among SpA patients and occurrence of AAU may be the reason for their first interaction with medical care, occurrence of AAU presents a unique opportunity for identifying such undiagnosed SpA patients. Therefore, a novel evidence-based algorithm called Dublin Uveitis Evaluation Tool (DUET) has been proposed to guide ophthalmologists and primary care physicians to refer appropriate AAU patients to rheumatologists. In a large two-phase study, approximately 40 % of patients presenting with idiopathic AAU were noted to have undiagnosed SpA, and DUET algorithm was noted to have excellent sensitivity (96 %) and specificity (97 %). It has a positive likelihood ratio (LR) 41.5 and negative LR 0.03. In most instances, the eye inflammation responds well to corticosteroid and mydriatic eye drops and without the need for additional therapy. Use of oral corticosteroids is reserved for patients, especially with associated chronic inflammatory bowel disease or psoriatic arthritis presenting with bilateral, chronic, anterior, and/or intermediate uveitis, and this treatment is rarely needed for more than a couple of weeks. A very small percentage may be more refractory to such treatment and require potential novel therapies, including the use of tumor necrosis factor blockers. PMID:26233598

  17. Baixa prevalência das manifestações extra-articulares renais, cardíacas, pulmonares e neurológicas nas espondiloartrites: análise do Registro Brasileiro de Espondiloartrites Low prevalence of renal, cardiac, pulmonary, and neurological extra-articular clinical manifestations in spondyloarthritis: analysis of the Brazilian Registry of Spondyloarthritis

    Directory of Open Access Journals (Sweden)

    Carlos Ewerton Maia Rodrigues

    2012-06-01

    Full Text Available OBJETIVO: Descrever as manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas geralmente não relacionadas às espondiloartrites (EpA em uma grande coorte de pacientes brasileiros. MÉTODOS: Este estudo retrospectivo analisou 1.472 pacientes com o diagnóstico de EpA atendidos em 29 centros distribuídos pelas cinco principais regiões geográficas do Brasil, integrantes do Registro Brasileiro de Espondiloartrites. Todos os pacientes foram avaliados para a prevalência das principais manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas, divididas por diagnóstico [espondilite anquilosante (EA, artrite psoriásica (AP, artrite reativa (ARe, artrite associada a doença inflamatória intestinal (DII, EpA indiferenciada (EI e EpA juvenil] e por forma clínica (axial, periférica, mista e entesítica. RESULTADOS: Dentre os pacientes avaliados com EpA, 963 apresentavam EA, 271 AP, 49 ARe, 48 artrite associada a DII, 98 EI e 43 EpA juvenil. Acometimento cardíaco foi observado em 44 pacientes (3,0%, seguido por acometimento pulmonar em 19 (1,3%, renal em 17 (1,2% e neurológico em 13 pacientes (0,9%. A maioria dos casos de acometimento visceral ocorreu nos pacientes com EA ou AP e naqueles com forma clínica mista (axial e periférica e/ou predominantemente axial. CONCLUSÃO: As manifestações extra-articulares cardíacas, renais, pulmonares e neurológicas são muito pouco frequentes nas EpA, variando de 0,9%-3% nesta grande coorte brasileira, estando mais associadas a EA e AP.OBJECTIVE: To describe the extra-articular manifestations (cardiac, renal, pulmonary, and neurological, usually not related to spondyloarthritis (SpA, in a large cohort of Brazilian patients. MATERIALS AND METHODS: This retrospective study analyzed 1,472 patients diagnosed with SpA and cared for at 29 health care centers distributed in the five major geographic regions in the country, participating in the Brazilian

  18. Prevalence of Peri-Implant Mucositis and Peri-Implantitis in Patients Treated with a Combination of Axial and Tilted Implants Supporting a Complete Fixed Denture

    Directory of Open Access Journals (Sweden)

    Nicolò Cavalli

    2015-01-01

    Full Text Available Objectives. The aim of this retrospective study was to assess the incidence and prevalence of peri-implant mucositis and peri-implantitis in patients with a fixed full-arch prosthesis supported by two axial and two tilted implants. Materials and Methods. Sixty-nine patients were included in the study. Each patient received a fixed full-arch prosthesis supported by two mesial axial and two distal tilted implants to rehabilitate the upper arch, the lower arch, or both. Three hundred thirty-six implants for 84 restorations were delivered. Patients were scheduled for follow-up visits every 6 months in the first 2 years and yearly after. At each follow-up visit peri-implant mucositis and peri-implantitis were diagnosed if present. Results. The overall follow-up range was from 12 to 130 months (mean 63,2 months. Three patients presented peri-implantitis. The prevalence of peri-implant mucositis ranged between 0 and 7,14% of patients (5,06% of implants while the prevalence of peri-implantitis varied from 0 to 4,55% of patients (3,81% of implants. Conclusions. The prevalence and incidence of peri-implant mucositis and peri-implantitis are lower than most of the studies in literature. Therefore this kind of rehabilitation could be considered a feasible option, on the condition of adopting a systematic hygienic protocol.

  19. Circulating levels of interleukin-6, vascular endothelial growth factor, YKL-40, matrix metalloproteinase-3, and total aggrecan in spondyloarthritis patients during 3 years of treatment with TNFα inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Hetland, Merete Lund; Sørensen, Inge Juul; Østergaard, Mikkel; Nielsen, Hans Jørgen; Johansen, Julia Sidenius

    2010-01-01

    The objectives of the study were to investigate short and long-term changes and relations to treatment response of plasma interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), YKL-40, matrix metalloproteinase-3 (MMP-3), and total aggrecan in patients with spondyloarthritis (SpA) treated...... with tumor necrosis factor-alpha (TNFα) inhibitors and to compare with levels in healthy subjects. Biomarkers were measured in an observational cohort of 49 SpA patients (ankylosing spondylitis, n=32, and psoriatic arthritis, n=17) initiating TNFα inhibitor therapy (infliximab, n=38; etanercept, n=8...

  20. Circulating levels of interleukin-6, vascular endothelial growth factor, YKL-40, matrix metalloproteinase-3, and total aggrecan in spondyloarthritis patients during 3 years of treatment with TNF alpha inhibitors

    DEFF Research Database (Denmark)

    Pedersen, S.J.; Hetland, M.L.; Sørensen, Inge Juul; Østergaard, Mikkel; Nielsen, H.J.; Johansen, J.S.

    2010-01-01

    The objectives of the study were to investigate short and long-term changes and relations to treatment response of plasma interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), YKL-40, matrix metalloproteinase-3 (MMP-3), and total aggrecan in patients with spondyloarthritis (SpA) treated...... with tumor necrosis factor-alpha (TNF alpha) inhibitors and to compare with levels in healthy subjects. Biomarkers were measured in an observational cohort of 49 SpA patients (ankylosing spondylitis, n = 32, and psoriatic arthritis, n = 17) initiating TNF alpha inhibitor therapy (infliximab, n = 38...

  1. Circulating levels of interleukin-6, vascular endothelial growth factor, YKL-40, matrix metalloproteinase-3, and total aggrecan in spondyloarthritis patients during 3 years of treatment with TNFα inhibitors

    DEFF Research Database (Denmark)

    Sørensen, Inge Juul; Ostergaard, Mikkel; Nielsen, Hans Jørgen; Pedersen, Susanne Juhl; Hetland, Merete Lund; Østergaard, Mikkel; Johansen, Julia Sidenius

    2010-01-01

    The objectives of the study were to investigate short and long-term changes and relations to treatment response of plasma interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), YKL-40, matrix metalloproteinase-3 (MMP-3), and total aggrecan in patients with spondyloarthritis (SpA) treated...... with tumor necrosis factor-alpha (TNFa) inhibitors and to compare with levels in healthy subjects. Biomarkers were measured in an observational cohort of 49 SpA patients (ankylosing spondylitis, n=32, and psoriatic arthritis, n=17) initiating TNFa inhibitor therapy (infliximab, n=38; etanercept, n=8...

  2. Seronegative spondyloarthritis and Darier’s disease: more than a casual association?

    Directory of Open Access Journals (Sweden)

    C. Cosso

    2013-05-01

    Full Text Available A 46-year old man, affected by Darier’s disease (DD, was seen because of right hand pain, later extended to shoulders and ankles. Physical examination showed swelling and tenderness of the wrist, metacarpophalangeal and metatarsophalangeal joints, of the right Achilles tendon’s enthesis and of the left knee, with psoriatic-like lesions of the scalp. A diagnosis of seronegative spondyloarthritis, supported by HLA-B27 positivity and by the magnetic resonance imaging fi nding of hand synovitis and unilateral sacro-iliitis, was made. The correlation between DD, spondyloarthritis and psoriasis has been already anecdotally reported. Further observations may clarify if this association is more than casual.

  3. MR enterography to evaluate sub-clinical intestinal inflammation in children with spondyloarthritis

    OpenAIRE

    Stoll Matthew L; Patel Ashish S; Punaro Marilynn; Dempsey-Robertson Molly

    2012-01-01

    Abstract Background Magnetic resonance enterography (MRE) is an established tool to evaluate for changes associated with inflammatory bowel disease (IBD), but has not been studied in sub-clinical IBD. We sought to evaluate the use of MRE in children with spondyloarthritis (SpA), who are at risk of having sub-clinical gut inflammation. Methods Children with juvenile idiopathic arthritis (JIA) with evidence of intestinal inflammation as evidence by an abnormal fecal calprotectin assay were offe...

  4. Diagnostic value of pelvic enthesitis on MRI of the sacroiliac joints in spondyloarthritis

    Energy Technology Data Exchange (ETDEWEB)

    Jans, L.; Langenhove, C. van; Lambrecht, V.; Verstraete, K. [Ghent University Hospital, Department of Radiology and Medical Imaging, Gent (Belgium); Praet, L. van; Carron, P.; Elewaut, D.; Bosch, F.V. den [Ghent University Hospital, Department of Rheumatology, Gent (Belgium); Jaremko, J.L. [University of Alberta Hospital, Department of Radiology, Edmonton, Alberta (Canada)

    2014-04-15

    To determine the prevalence and diagnostic value of pelvic enthesitis on MRI of the sacroiliac (SI) joints in spondyloarthritis (SpA). A retrospective study in 444 patients aged 17-45 years old with MRI of the SI joints and with clinically suspected sacroiliitis was performed. Patients were classified as having SpA if they fulfilled the Assessment of Spondyloarthritis International Society (ASAS) criteria. Pelvic enthesitis on MRI was correlated with the final diagnosis. Sensitivity, specificity, positive and negative likelihood ratio (LR) and predictive values (PV) of pelvic enthesitis for the diagnosis of SpA were calculated. MRI showed pelvic enthesitis in 24.4 % of patients with SpA and in 7.1 % of patients without SpA. Presence of any enthesitis had sensitivity, specificity, LR+, LR-, PPV and NPV of 24.4 %, 92.9 %, 3.45, 0.81, 69.4 % and 65.2 % for the diagnosis of SpA, respectively. The most commonly affected entheses were the longitudinal ligament insertion (4.5 %), the retroarticular ligaments (4.1 %) and the pubic symphysis (4.1 %). The sites of enthesitis with the highest PPV for SpA were the iliac crest/wing (85.7 %) and the retroarticular ligaments (81.3 %). Nearly one fourth of SpA patients with suspected sacroiliitis showed pelvic enthesitis on MRI. Such pelvic enthesitis has a high specificity for the diagnosis of spondyloarthritis. (orig.)

  5. Diagnostic value of pelvic enthesitis on MRI of the sacroiliac joints in spondyloarthritis

    International Nuclear Information System (INIS)

    To determine the prevalence and diagnostic value of pelvic enthesitis on MRI of the sacroiliac (SI) joints in spondyloarthritis (SpA). A retrospective study in 444 patients aged 17-45 years old with MRI of the SI joints and with clinically suspected sacroiliitis was performed. Patients were classified as having SpA if they fulfilled the Assessment of Spondyloarthritis International Society (ASAS) criteria. Pelvic enthesitis on MRI was correlated with the final diagnosis. Sensitivity, specificity, positive and negative likelihood ratio (LR) and predictive values (PV) of pelvic enthesitis for the diagnosis of SpA were calculated. MRI showed pelvic enthesitis in 24.4 % of patients with SpA and in 7.1 % of patients without SpA. Presence of any enthesitis had sensitivity, specificity, LR+, LR-, PPV and NPV of 24.4 %, 92.9 %, 3.45, 0.81, 69.4 % and 65.2 % for the diagnosis of SpA, respectively. The most commonly affected entheses were the longitudinal ligament insertion (4.5 %), the retroarticular ligaments (4.1 %) and the pubic symphysis (4.1 %). The sites of enthesitis with the highest PPV for SpA were the iliac crest/wing (85.7 %) and the retroarticular ligaments (81.3 %). Nearly one fourth of SpA patients with suspected sacroiliitis showed pelvic enthesitis on MRI. Such pelvic enthesitis has a high specificity for the diagnosis of spondyloarthritis. (orig.)

  6. Role of HLA-B Alleles and Clinical Presentation of B27 Negative Spondyloarthritis Patients from Mumbai, Western India

    OpenAIRE

    Parasannanavar, Devaraj J.; Anjali Rajadhyaksha; Kanjaksha Ghosh

    2014-01-01

    Seronegative spondyloarthritis (SpA) are variably associated with HLA-B∗27 antigen. HLA-B∗27 negative SpA has also been reported from different parts of the world. There is paucity of data on this entity from Indian subcontinent. We studied 100 consecutively diagnosed HLA-B27 negative spondyloarthritis patients from a tertiary care center in India. Modified New York Criteria for ankylosing spondylitis (AS) and ESSG criteria for SpA were used for diagnosing patients. HLA-B∗27 typing was done b...

  7. Undifferentiated seronegative spondyloarthritis with inflammatory bowel disease and a family history of psoriasis. Sicca syndrome

    Directory of Open Access Journals (Sweden)

    Norma Marigliano

    2013-04-01

    Full Text Available Background: Seronegative spondyloarthritis is characterized by the presence of subcutaneous nodules, asymmetrical peripheral arthritis, sacroileitis with or without spondylitis, and rheumatoid-factor negativity. Other common clinical manifestations include oral ulcers, conjunctivitis, and cutaneous lesions such as psoriasis. Familial aggregation has also been described. According to the 1986 classification, corresponding clinical entities include ankylosing spondylitis, psoriatic arthritis, Reiter’s syndrome, arthritis associated with inflammatory bowel disease (IBD, and undifferentiated spondyloarthritis. The disease is also frequently associated with the HLA B27 antigen. From the clinical point of view, there are often incomplete forms of spondyloarthritis, such as reactive arthritis triggered by asymptomatic infections, psoriatic arthritis without psoriasis itself, initial phases of specific forms of spondyloarthritis or the phase of ankylosing spondylitis characterized by sacroiliac lesions, and all forms that remain undifferentiated for long periods of time. Moreover, there are close relations between arthropathy and IBDs, such as Crohn’s disease, ulcerative colitis, and Whipple’s syndrome. Recently, microscopic inflammatory bowel lesions and psoriatic arthritis have been described. Case report: A 30-year-old man (HLA B27-negative who had been vaccinated against TBC and HBV presented with a 6-year history of recurrent episodes of predominantly left-sided sciatica. The pain was worse at night and during rest. He was suffering from bilateral sacroileitis without spondylitis. Three to five times a day, usually after eating, he passed watery feces containing mucous and small amounts of bright red blood. Colonoscopy revealed pancolitis with histological evidence of chronic inflammation interspersed with areas of acute inflammation, edema, hyperemia, and glandular distortion. One year later, the clinical manifestations and histological

  8. Nefropatia por IgA nas espondiloartrites IgA nephropathy in spondyloarthritis

    Directory of Open Access Journals (Sweden)

    Daniela Castelo Azevedo

    2011-02-01

    Full Text Available Pacientes com espondiloartrites poderiam ser mais acometidos pela nefropatia por IgA do que a população geral, havendo, possivelmente, um mecanismo etiopatogênico comum. O seguinte artigo relaciona quatro casos que exemplificam essa possível associaçãoSpondyloarthritis patients can be more frequently affected by IgA nephropathy than the general population, and a common etiopathogenic mechanism can be involved. We report four cases that may exemplify that association

  9. Extra-Axial Medulloblastoma in the Cerebellar Hemisphere

    OpenAIRE

    Chung, Eui Jin; Jeun, Sin Soo

    2014-01-01

    Extra-axial medulloblastoma is a rare phenomenon. We report a case in a 5-year-old boy who presented with nausea, vomiting, and gait disturbance. He was treated with total removal of the tumor. This is the first case of an extra-axially located medulloblastoma occurring in the cerebellar hemisphere posteriolateral to the cerebellopontine angle in Korea. Although the extra-axial occurrence of medulloblastoma is rare, it should be considered in the differential diagnosis of extra-axial lesions ...

  10. Indirect and direct costs of treating patients with ankylosing spondylitis in the Brazilian public health system

    OpenAIRE

    Valderilio Feijó Azevedo; Chayanne N. Rossetto; Lorencetti, Pedro G.; Mariana Y. Tramontin; Bruna Fornazari; Denizar V. Araújo

    2016-01-01

    ABSTRACT Introduction: Patients with Ankylosing Spondylitis (AS) require a team approach from multiple professionals, various treatment modalities for continuous periods of time, and can lead to the loss of labour capacity in a young population. So, it is necessary to measure its socio-economic impact. Objectives: To describe the use of public resources to treat AS in a tertiary hospital after the use of biological medications was approved for treating spondyloarthritis in the Health Public...

  11. Safety of Etoricoxib, Celecoxib, and Nonselective Nonsteroidal Antiinflammatory Drugs in Ankylosing Spondylitis and Other Spondyloarthritis Patients

    DEFF Research Database (Denmark)

    Kristensen, L E; Jakobsen, A K; Askling, J; Nilsson, F; Jacobsson, L T H

    2015-01-01

    OBJECTIVE: Safety data regarding the use of etoricoxib and other nonsteroidal antiinflammatory drugs (NSAIDs) in ankylosing spondylitis (AS) and other spondyloarthritis (SpA) patients are rather limited. Our objective was to estimate and compare rates of gastrointestinal, renovascular, and...... cardiovascular adverse events in patients exposed to etoricoxib, celecoxib, or nonselective NSAIDs or totally unexposed to NSAIDs. METHODS: We performed a national register-based cohort study on patients with AS or SpA (n = 21,872) identified in the Swedish national patient register from 1987-2009. Treatment...... exposure was assessed time dependently based on the prescription drug register from 2006-2009, adjusting for sociodemographics and comorbidities derived from national population-based registers. RESULTS: Exposure to etoricoxib, celecoxib, and nonselective NSAIDs was 7.6%, 3.9%, and 71.2%, respectively. No...

  12. IL-23/IL-17 axis in spondyloarthritis-bench to bedside.

    Science.gov (United States)

    Raychaudhuri, Siba P; Raychaudhuri, Smriti K

    2016-06-01

    Cytokines play a critical role in the pathogenesis of psoriatic arthritis, ankylosing spondylitis, and other types of spondyloarthritis (SpA). Besides IFN-γ and TNF-α; IL-23/IL-17 cytokines play a dominant role in the inflammatory and proliferative cascades of SpA. Recently, in a series of elegant experiments using mouse models and human tissues, it has been demonstrated that IL-23-induced Th17 cytokines (IL-17 and IL-22) can contribute to following pathologic events associated with SpA: development of psoriatic plaque, pannus formation in the joint, joint erosion, and new bone formation. In this review article, we have discussed the contributing role of the IL-23/IL-17 cytokine axis in the pathogenesis of PsA and AS. IL-23/IL-17-targeted therapies are very promising for SpA, and we have provided an outline about usefulness of these new groups of biologics in SpA. PMID:27075462

  13. BWR AXIAL PROFILE

    International Nuclear Information System (INIS)

    The purpose of this calculation is to develop axial profiles for estimating the axial variation in burnup of a boiling water reactor (BWR) assembly spent nuclear fuel (SNF) given the average burnup of an assembly. A discharged fuel assembly typically exhibits higher burnup in the center and lower burnup at the ends of the assembly. Criticality safety analyses taking credit for SNF burnup must account for axially varying burnup relative to calculations based on uniformly distributed assembly average burnup due to the under-burned tips. Thus, accounting for axially varying burnup in criticality analyses is also referred to as accounting for the ''end effect'' reactivity. The magnitude of the reactivity change due to ''end effect'' is dependent on the initial assembly enrichment, the assembly average burnup, and the particular axial profile characterizing the burnup distribution. The set of bounding axial profiles should incorporate multiple BWR core designs and provide statistical confidence (95 percent confidence that 95 percent of the population is bound by the profile) that end nodes are conservatively represented. The profiles should also conserve the overall burnup of the fuel assembly. More background on BWR axial profiles is provided in Attachment I

  14. BWR AXIAL PROFILE

    Energy Technology Data Exchange (ETDEWEB)

    J. Huffer

    2004-09-28

    The purpose of this calculation is to develop axial profiles for estimating the axial variation in burnup of a boiling water reactor (BWR) assembly spent nuclear fuel (SNF) given the average burnup of an assembly. A discharged fuel assembly typically exhibits higher burnup in the center and lower burnup at the ends of the assembly. Criticality safety analyses taking credit for SNF burnup must account for axially varying burnup relative to calculations based on uniformly distributed assembly average burnup due to the under-burned tips. Thus, accounting for axially varying burnup in criticality analyses is also referred to as accounting for the ''end effect'' reactivity. The magnitude of the reactivity change due to ''end effect'' is dependent on the initial assembly enrichment, the assembly average burnup, and the particular axial profile characterizing the burnup distribution. The set of bounding axial profiles should incorporate multiple BWR core designs and provide statistical confidence (95 percent confidence that 95 percent of the population is bound by the profile) that end nodes are conservatively represented. The profiles should also conserve the overall burnup of the fuel assembly. More background on BWR axial profiles is provided in Attachment I.

  15. Aberrant expression of shared master-key genes contributes to the immunopathogenesis in patients with juvenile spondyloarthritis.

    Directory of Open Access Journals (Sweden)

    Lovro Lamot

    Full Text Available Association of juvenile spondyloarthritis (jSpA with the HLA-B27 genotype is well established, but there is little knowledge of other genetic factors with a role in the development of the disease. To date, only a few studies have tried to find those associated genes by obtaining expression profiles, but with inconsistent results due to various patient selection criteria and methodology. The aim of the present study was to identify and confirm gene signatures and novel biomarkers in highly homogeneous cohorts of untreated and treated patients diagnosed with jSpA and other forms of juvenile idiopathic arthritis (JIA according to ILAR criteria. For the purposes of the research, total RNA was isolated from whole blood of 45 children with jSpA and known HLA genotype, 11 children with oligo- and polyarticular forms of JIA, as well as 12 age and sex matched control participants without diagnosis of inflammatory disease. DNA microarray gene expression was performed in 11 patients with jSpA and in four healthy controls, along with bioinformatical analysis of retrieved data. Carefully selected differentially expressed genes where analyzed by qRT-PCR in all participants of the study. Microarray results and bioinformatical analysis revealed 745 differentially expressed genes involved in various inflammatory processes, while qRT-PCR analysis of selected genes confirmed data universality and specificity of expression profiles in jSpA patients. The present study indicates that jSpA could be a polygenic disease with a possible malfunction in antigen recognition and activation of immunological response, migration of inflammatory cells and regulation of the immune system. Among genes involved in these processes TLR4, NLRP3, CXCR4 and PTPN12 showed almost consistent expression in study patients diagnosed with jSpA. Those genes and their products could therefore potentially be used as novel biomarkers, possibly predictive of disease prognosis and response to

  16. Signatures for axial chromodynamics

    International Nuclear Information System (INIS)

    Within the context of basic left-right symmetry and the hypothesis of unification of weak, electromagnetic and strong forces at a mass level approximately equal to 104-106 GeV, relatively light ''mass'' axial gluons, confined or liberated, must be postulated. The authors remark that the existence of such ''light'' axial gluons supplementing the familiar vector octet preserves the successes of QCD, both for deep inelastic processes and charmonium physics. Through the characteristic spin-spin force, generated by their exchange, they may even help resolve some of the discrepancies between vector QCD predictions and charmonium physics. The main remark of this note is that if colour is liberated, not only vector but also axial-vector gluons are produced in high-energy e-e+ experiments, e.g. at PETRA and PEP, with fairly large cross-section. Distinctive decay modes of such liberated axial gluons are noted

  17. Surface nanoscale axial photonics

    OpenAIRE

    Sumetsky, M.; Fini, J. M.

    2011-01-01

    Dense photonic integration promises to revolutionize optical computing and communications. However, efforts towards this goal face unacceptable attenuation of light caused by surface roughness in microscopic devices. Here we address this problem by introducing Surface Nanoscale Axial Photonics (SNAP). The SNAP platform is based on whispering gallery modes circulating around the optical fiber surface and undergoing slow axial propagation readily described by the one-dimensional Schr\\"odinger e...

  18. Increased Levels of IgG Antibodies against Human HSP60 in Patients with Spondyloarthritis

    DEFF Research Database (Denmark)

    Nielsen, Astrid Hjelholt; Carlsen, Thomas; Deleuran, Bent;

    2013-01-01

    Introduction: Spondyloarthritis (SpA) comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA)-B27. SpA is suggested triggered by bacterial infection, and bacterial heat shock protein (HSP) seems to be a strong T cell antigen. Since...... severity in relation to HLA-B27 was evaluated. Material & Methods: Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella...... against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27+ patients. Only weak correlation between antibodies against bacterial and human HSP60 was...

  19. Role of HLA-B Alleles and Clinical Presentation of B27 Negative Spondyloarthritis Patients from Mumbai, Western India

    Directory of Open Access Journals (Sweden)

    Devaraj J. Parasannanavar

    2014-01-01

    Full Text Available Seronegative spondyloarthritis (SpA are variably associated with HLA-B*27 antigen. HLA-B*27 negative SpA has also been reported from different parts of the world. There is paucity of data on this entity from Indian subcontinent. We studied 100 consecutively diagnosed HLA-B27 negative spondyloarthritis patients from a tertiary care center in India. Modified New York Criteria for ankylosing spondylitis (AS and ESSG criteria for SpA were used for diagnosing patients. HLA-B*27 typing was done by an in-house PCR-SSP technique in SpA patients to exclude B*27 positive patients and PCR-SSOP technique was used to type 100 B*27 negative SpA patients and 100 controls from the same ethnicity. Frequency of B*07 was significantly increased (B*07: % PF 54 versus 18; OR 5.348; 95% CI 2.808–10.186; P value 1.14E − 07, whereas frequency of B*40 was significantly decreased (B*40: % PF 17 versus 32; OR 0.435; 95% CI 0.222–0.850; P value 0.013 when compared with B*27 negative controls. Among 100 SpA patients, 47 were undifferentiated spondyloarthritis and 33 patients were reactive arthritis patients. 40% of the patients were suffering from polyarticular arthritis, 35% had pauciarticular arthritis with knee joint, hip joint, ankle joint, and SI joint involvement. We conclude that B*07 was significantly associated with B27 negative spondyloarthropathy from Western India and majority of B*27 negative patients were uSpA.

  20. Enthesitis of lumbar spinal ligaments in clinically suspected spondyloarthritis: value of gadolinium-enhanced MR images in comparison to STIR

    Energy Technology Data Exchange (ETDEWEB)

    Agten, Christoph A.; Zubler, Veronika; Rosskopf, Andrea B.; Pfirrmann, Christian W.A. [Balgrist University Hospital, Radiology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland); Weiss, Bettina [Balgrist University Hospital, Rheumatology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland)

    2016-02-15

    To compare detection of spinal ligament enthesitis between gadolinium-enhanced fat-saturated T1-weighted gadolinium-enhanced fat-saturated T1-weighted (T1+Gd) and STIR sequences in patients with suspected spondyloarthritis. Sixty-eight patients (37 males, 42 ± 14 years) with a sacroiliac-joint (SIJ) and lumbar spine MRI for suspected spondyloarthritis were prospectively included. Sagittal T1+Gd and STIR images of the lumbar spine were assessed by two readers for enthesitis of interspinous/supraspinous ligaments, and for capsulitis of facet-joints between T12-S1. Patients' MRI were grouped according to ASAS (Assessment of SpondyloArthritis international Society) criteria in positive (group A) or negative (group B) SIJs. Enthesitis/capsulitis were compared between groups. Interreader agreement was assessed. Enthesitis/capsulitis per patient was statistically significantly more frequent with T1+Gd compared to STIR (p ≤ 0.007), except for interspinous ligaments for reader 1 (p = 0.455). Interspinous enthesitis, supraspinous enthesitis, and capsulitis were present with T1+Gd(STIR) in 64.7 %(72.1 %), 60.3 %(17.7 %), and 61.8 %(29.4 %) for reader 1, and 51.5 %(41.2 %), 45.6 %(7.4 %), and 91.2 %(45.5 %) for reader 2. There were 76.5 %(52/68) patients in group A and 23.5 %(16/68) in group B. Total number of enthesitis/capsulitis on T1+Gd was statistically significantly higher in group A than B (4.96 vs. 2.94, p = 0.026; 8.12 vs. 5.25, p = 0.041 for reader 1 and 2, respectively). Interreader agreement showed mixed results for interspinous/supraspinous/capsulitis but was higher on T1+Gd (ICC = 0.838/0.783/0.367; p ≤ 0.001) compared to STIR (ICC = 0.652/0.298/0.224; p ≤ 0.032). In patients with suspected spondyloarthritis, enthesitis/capsulitis in the lumbar spine are common findings and more frequently/reliably detected with T1+Gd than STIR. In patients with positive SIJ-MRI, the total number of enthesitis/capsulitis in T1+Gd was higher compared to patients with

  1. Enthesitis of lumbar spinal ligaments in clinically suspected spondyloarthritis: value of gadolinium-enhanced MR images in comparison to STIR

    International Nuclear Information System (INIS)

    To compare detection of spinal ligament enthesitis between gadolinium-enhanced fat-saturated T1-weighted gadolinium-enhanced fat-saturated T1-weighted (T1+Gd) and STIR sequences in patients with suspected spondyloarthritis. Sixty-eight patients (37 males, 42 ± 14 years) with a sacroiliac-joint (SIJ) and lumbar spine MRI for suspected spondyloarthritis were prospectively included. Sagittal T1+Gd and STIR images of the lumbar spine were assessed by two readers for enthesitis of interspinous/supraspinous ligaments, and for capsulitis of facet-joints between T12-S1. Patients' MRI were grouped according to ASAS (Assessment of SpondyloArthritis international Society) criteria in positive (group A) or negative (group B) SIJs. Enthesitis/capsulitis were compared between groups. Interreader agreement was assessed. Enthesitis/capsulitis per patient was statistically significantly more frequent with T1+Gd compared to STIR (p ≤ 0.007), except for interspinous ligaments for reader 1 (p = 0.455). Interspinous enthesitis, supraspinous enthesitis, and capsulitis were present with T1+Gd(STIR) in 64.7 %(72.1 %), 60.3 %(17.7 %), and 61.8 %(29.4 %) for reader 1, and 51.5 %(41.2 %), 45.6 %(7.4 %), and 91.2 %(45.5 %) for reader 2. There were 76.5 %(52/68) patients in group A and 23.5 %(16/68) in group B. Total number of enthesitis/capsulitis on T1+Gd was statistically significantly higher in group A than B (4.96 vs. 2.94, p = 0.026; 8.12 vs. 5.25, p = 0.041 for reader 1 and 2, respectively). Interreader agreement showed mixed results for interspinous/supraspinous/capsulitis but was higher on T1+Gd (ICC = 0.838/0.783/0.367; p ≤ 0.001) compared to STIR (ICC = 0.652/0.298/0.224; p ≤ 0.032). In patients with suspected spondyloarthritis, enthesitis/capsulitis in the lumbar spine are common findings and more frequently/reliably detected with T1+Gd than STIR. In patients with positive SIJ-MRI, the total number of enthesitis/capsulitis in T1+Gd was higher compared to patients with

  2. On renormalization of axial anomaly

    International Nuclear Information System (INIS)

    It is shown that multiplicative renormalization of the axial singlet current results in renormalization of the axial anomaly in all orders of perturbation theory. It is a necessary condition for the Adler - Bardeen theorem being valid. 10 refs.; 2 figs

  3. Axial compressor stability enhancement

    OpenAIRE

    Houghton, Timothy Oliver.

    2010-01-01

    Aircraft jet engines must operate in a stable manner at all times. One source of instability is compressor stall. Stall problems can be reduced by machining cavities into the compressor casing adjacent to the rotor blades. This ?casing treatment? is the focus of the present work. Two treatment configurations are tested: circumferential grooves cut into the casing above the rotor blades, and axial slots cut into the casing adjacent to the rotor blade leading edges. The performance of a single ...

  4. Association and frequency of HLA-A, B and HLA-DR genes in south Tunisian patients with spondyloarthritis (SpA)

    NARCIS (Netherlands)

    N. Mahfoudh; M. Siala; M. Rihl; A. Kammoun; F. Frikha; H. Fourati; M. Younes; R. Gdoura; L. Gaddour; F. Hakim; Z. Bahloul; S. Baklouti; N. Bargaoui; S. Sellami; A. Hammami; H. Makni

    2011-01-01

    The aim of this study is to investigate the association of HLA-A, B and HLA-DR gene expression and to assess an association of additional HLA antigens besides HLA-B27 in south Tunisian patients with spondyloarthritis (SpA). Eighty-five patients diagnosed with ankylosing spondylitis (AS, n = 68) and

  5. MRI grading method for active and chronic spinal changes in spondyloarthritis

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, K.B. [Department of Radiology, Aarhus University Hospital, Aarhus Sygehus (Denmark); Jurik, A.G., E-mail: anne.jurik@aarhus.rm.d [Department of Radiology, Aarhus University Hospital, Aarhus Sygehus (Denmark)

    2010-01-15

    Aim: To describe a magnetic resonance imaging (MRI) grading method for both active and chronic spondyloarthritis (SpA) changes in the spine, to test its validity, and compare chronic MRI scores with findings obtained by radiography. Material and methods: A total of 91 patients (41 males; 50 females) with back pain fulfilling the European Spondylarthropathy Study Group (ESSG) criteria for SpA were examined using MRI and radiography of the spine. The mean age was 36.7 years (range 16-51 years) and symptom duration was between 3 and 27 years. The MRI images were assessed for signs of disease activity (bone marrow oedema at the vertebral plates and costo-vertebral joints) and chronic structural changes [syndesmophytes/vertebral fusion, erosion, and fatty marrow deposition (FMD)]. The interobserver agreement was analysed based on 37 examinations. Radiographs were assessed for the presence of shiny corners, vertebral squaring, syndesmophytes/fusion, and erosion. Results: The interobserver agreement for the assessed MRI abnormalities was acceptable, with kappa values between 0.62 and 0.77. A total of 56 patients had SpA-related spinal abnormalities as depicted using MRI. The total chronic MRI score was not significantly related to the radiographic score, mainly because syndesmophytes were difficult to detect by MRI and FMD was only visualized by MRI. However, FMD was significantly related to the total radiographic score and vertebral squaring. Conclusion: The described MRI grading method was reliable for assessing both disease activity and chronic changes. MRI is promising for estimating chronic changes, but cervical radiography may still be needed. FMD seems to be an important sign of chronicity.

  6. The Bench-to-Bedside Story of IL-17 and the Therapeutic Efficacy of its Targeting in Spondyloarthritis.

    Science.gov (United States)

    Smith, Judith A

    2016-06-01

    TNF-blocking biologics have revolutionized the care of patients with spondyloarthritis, a group of clinically overlapping conditions that includes ankylosing spondylitis and psoriatic arthritis. However, incomplete response rates speak to the need for alternative therapeutic approaches. Over the last decade, animal models, genetics, and translational studies have implicated the excessive production of a pro-inflammatory cytokine interleukin-17 (IL-17) along with another IL-17-promoting cytokine IL-23 in the pathogenesis of spondyloarthritis. Genome-wide studies identified disease associations with multiple genes regulating IL-23/IL-17 immune pathway activity. Direct examination of the patient blood and tissues revealed excessive IL-17 and IL-23 production by diverse cell types. Murine models both underscored the sufficiency of excess IL-23 in driving disease phenotype and predicted utility in IL-23/IL-17 pathway blockade. However, the clinical efficacy of agents such as secukinumab and ustekinumab, which block IL-17 and IL-23/IL-12 respectively, provided exciting proof of concept. PMID:27105640

  7. Critical Axial Load

    Directory of Open Access Journals (Sweden)

    Walt Wells

    2008-01-01

    Full Text Available Our objective in this paper is to solve a second order differential equation for a long, simply supported column member subjected to a lateral axial load using Heun's numerical method. We will use the solution to find the critical load at which the column member will fail due to buckling. We will calculate this load using Euler's derived analytical approach for an exact solution, as well as Euler's Numerical Method. We will then compare the three calculated values to see how much they deviate from one another. During the critical load calculation, it will be necessary to calculate the moment of inertia for the column member.

  8. Axial skeletal CT densitometry

    International Nuclear Information System (INIS)

    Since the discovery of the Roentgen ray a precise and accurate assessment of bone mineral content has been a challenge to many investigators. A number of methods have been developed but no one satisfied. Considering its technical possibilities computed tomography is very promising in determination of bone mineral content (BMC). The new modality enables BMC estimations in the axial skeletal trabecular bone. CT densitometry can be performed on a normal commercially available third generation whole body CT scanner. No dedicated device in a special clinical set-up is necessary. In this study 106 patients, most of them clinically suspected of osteoporosis, were examined. The new method CT densitometry has been evaluated. The results have been correlated to alternative BMC determination methods. (Auth.)

  9. Clinical uveitis evaluation and its value in the diagnosis of spondyloarthritis

    Directory of Open Access Journals (Sweden)

    Alla Aleksandrovna Godzenko

    2011-01-01

    Full Text Available Objective: to estimate the value of clinical parameters of uveitis for the diagnosis of spondyloarthritis (SA. Subjects and methods. One hundred and five uveitis patients referred by ophthalmologists to the Research Institute of Rheumatology, Russian Academy of Medical Sciences, in 2007–2009 were examined. X-ray study of the pelvis and lumbar spine, HLA-B27 test, and objective examination were performed in all the patients to detect inflammatory back pain, arthritis, and enthesitis. Results. The diagnosis of SA was verified in 60 patients: 24 had ankylosing spondylitis, 2 had reactive arthritis, and 38 had undifferentiat ed SA. The diagnosis of SA was discarded in 45 patients. Subsequent examination of these patients diagnosed BehНet's disease in 2 of them, sarcoidosis in 1, toxoplasmosis in 4, virus infection-associated uveitis in 8, Fuchs' syndrome in 1, and unspecified uveitis in 29. There was unilateral uveitis in 51 (85% of the 60 patients with SP and in 26 (58% of the 45 patients without SP (p = 0.0033; alternat ing eye lesion in 30 (50% of the 60 patients with SP and in 4 (8.9% of the 45 patients without SP (p = 0.00001; anterior uveitis in 57 (95% of the 60 patients with SP and in 32 of the 45 patients without SP (p = 0.0017; posterior uveitis in 6 (10% of the 60 patients with SP and in 20 (44% of the 45 patients without SP (p = 0.0001; panuveitis in 2 (3.3% of the 60 patients with SP and in 10 (22.2% of the 45 patients without SP (p = 0.0039, acute recurrent uveitis in 15 (33.3% of the 45 patients without SP and in 44 (73% of the 60 patients with SP (p = 0.0001. The age at onset was less than 30 years in 38 patients with SP and in 19 patients without SP (p = 0.04. Conclusion. The estimation of the location and course of uveitis is important in diagnosing SP that is probable in patients with acute anteri or unilateral uveitis with alternating eye lesion, which occurred before the age of 30 years.

  10. Costs of early spondyloarthritis: estimates from the first 3 years of the DESIR cohort

    Science.gov (United States)

    Harvard, Stephanie; Guh, Daphne; Bansback, Nick; Richette, Pascal; Dougados, Maxime; Anis, Aslam; Fautrel, Bruno

    2016-01-01

    Objectives To value health resource utilisation and productivity losses in DESIR, a longitudinal French cohort of 708 patients with early spondyloarthritis (SpA) enrolled between 2007 and 2010, and identify factors associated with costs in the first 3 years of follow-up. Methods Self-reported clinical data from DESIR and French public data were used to value health resource utilisation and productivity losses in 2013 Euros. Factors associated with costs, including and excluding biological drugs, were identified in generalised linear models using the generalised estimating equations algorithm to account for repeated observations over participants. Results The mean (±SD) annual cost per patient was €5004±6870 in year 1, decreasing to €4961±7457 in year 3. Patients who never received a biologic had mean 3-year total costs of €4789±6022 compared to €38 206±19 829 among those who received a biologic. Factors associated with increased total costs were peripheral arthritis (rate ratio (RR) 1.19; 95% CI 1.04 to 1.37; p<0.0001), time on biologics (RR 1.23 per month; 1.21, 1.24; p<0.0001), and average BASFI score (RR 1.18/10 point increase; 1.15, 1.25; p<0.0001). Factors associated with increased costs excluding biologics were baseline age (RR 1.10 per 5 year increase; 1.05, 1.16; p<0.0001), peripheral arthritis (RR 1.20; 1.02, 1.40; p<0.0133), time on biologics (RR 1.04 per month; 1.02, 1.05; p<0.0001), and average BASDAI score (RR 1.21 per 10 point increase; 1.16, 1.25; p<0.0001). Conclusions In addition to biologics, factors like age, peripheral arthritis and disease activity independently increase SpA-related costs. This study may serve as a benchmark for cost of illness among patients with early SpA in the biologic era. PMID:27099778

  11. Increased levels of IgG antibodies against human HSP60 in patients with spondyloarthritis.

    Directory of Open Access Journals (Sweden)

    Astrid Hjelholt

    Full Text Available Spondyloarthritis (SpA comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA-B27. A triggering bacterial infection has been considered as the cause of SpA, and bacterial heat shock protein (HSP seems to be a strong T cell antigen. Since bacterial and human HSP60, also named HSPD1, are highly homologous, cross-reactivity has been suggested in disease initiation. In this study, levels of antibodies against bacterial and human HSP60 were analysed in SpA patients and healthy controls, and the association between such antibodies and disease severity in relation to HLA-B27 was evaluated.Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA for immunoglobulin (IgG1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella enteritidis and Campylobacter jejuni. Disease severity was assessed by the clinical scorings Bath Ankylosing Spondylitis Disease Activity Index (BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI and Bath Ankylosing Spondylitis Metrology Index (BASMI. Levels of IgG1 and IgG3 antibodies against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27⁺ patients. Only weak correlation between antibodies against bacterial and human HSP60 was seen, and there was no indication of cross-reaction. These results suggest that antibodies against human HSP60 is associated with SpA, however, the theory that antibodies against human HSP60 is a specific part of the aetiology, through cross-reaction to bacterial HSP60, cannot be supported by results from this study. We suggest that the association between elevated levels of antibodies against human HSP60 and disease may reflect a general activation of the immune system and an increased

  12. Axial anomaly in nonrenormalizable theories

    International Nuclear Information System (INIS)

    The anomaly for the axial current in nonrenormalizable theories with electromagnetic coupling is considered. The spinor electrodynamics with Pauli term is examined in detail using the Feynman graph technique and the point-splitting method. The same finite value for the axial anomaly emerges. (author)

  13. Extra-axial brain tumors.

    Science.gov (United States)

    Rapalino, Otto; Smirniotopoulos, James G

    2016-01-01

    Extra-axial brain tumors are the most common adult intracranial neoplasms and encompass a broad spectrum of pathologic subtypes. Meningiomas are the most common extra-axial brain tumor (approximately one-third of all intracranial neoplasms) and typically present as slowly growing dural-based masses. Benign meningiomas are very common, and may occasionally be difficult to differentiate from more aggressive subtypes (i.e., atypical or malignant varieties) or other dural-based masses with more aggressive biologic behavior (e.g., hemangiopericytoma or dural-based metastases). Many neoplasms that typically affect the brain parenchyma (intra-axial), such as gliomas, may also present with primary or secondary extra-axial involvement. This chapter provides a general and concise overview of the common types of extra-axial tumors and their typical imaging features. PMID:27432671

  14. Build Axial Gradient Field by Using Axial Magnetized Permanent Rings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Axial magnetic field produced by an axial magnetized permanent ring was studied. For two permanent rings, if they are magnetized in the same directions, a nearly uniform axial field can be produced. If they are magnetized in opposite direction,an axial gradient magnetic field can be generated, with the field range changing from -B0 to B0. A permanent magnet with a high axial gradient field was fabricated, the measured results agree with the PANDIRA calculation very well. For wider usage,it is desirable for the field gradient to be changed. Some methods to produce the variable gradient field are presented. These kinds of axial gradient magnetic field can also be used as a beam focusing for linear accelerator if the periodic field can be produced along the beam trajectory. The axial magnetic field is something like a solenoid, large stray field will leak to the outside environment if no method is taken to control them. In this paper, one method is illustrated to shield off the outside leakage field.

  15. Dissipative Axial Inflation

    CERN Document Server

    Notari, Alessio

    2016-01-01

    We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term $\\frac{\\phi}{f_\\gamma} F \\tilde{F}$, such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density $\\rho_R$, which which can lead to inflation without the need of a flat potential. We analyze the system, for momenta $k$ smaller than the cutoff $f_\\gamma$, including numerically the backreaction. We consider the evolution from a given static initial condition and explicitly show that, if $f_\\gamma$ is smaller than the field excursion $\\phi_0$ by about a factor of at least ${\\cal O} (20)$, there is a friction effect which turns on before that the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of...

  16. Axial Patterning in Hydra

    Science.gov (United States)

    Bode, Hans R.

    2009-01-01

    Morphogen gradients play an important role in pattern formation during early stages of embryonic development in many bilaterians. In an adult hydra, axial patterning processes are constantly active because of the tissue dynamics in the adult. These processes include an organizer region in the head, which continuously produces and transmits two signals that are distributed in gradients down the body column. One signal sets up and maintains the head activation gradient, which is a morphogenetic gradient. This gradient confers the capacity of head formation on tissue of the body column, which takes place during bud formation, hydra's mode of asexual reproduction, as well as during head regeneration following bisection of the animal anywhere along the body column. The other signal sets up the head inhibition gradient, which prevents head formation, thereby restricting bud formation to the lower part of the body column in an adult hydra. Little is known about the molecular basis of the two gradients. In contrast, the canonical Wnt pathway plays a central role in setting up and maintaining the head organizer. PMID:20066073

  17. Does spinal MRI add incremental diagnostic value to MRI of the sacroiliac joints alone in patients with non-radiographic axial spondyloarthritis?

    DEFF Research Database (Denmark)

    Weber, Ulrich; Zubler, Veronika; Zhao, Zheng; Lambert, Robert G W; Chan, Stanley M; Pedersen, Susanne Juhl; Østergaard, Mikkel; Rufibach, Kaspar; Maksymowych, Walter P

    2015-01-01

    assessed SIJ and spine MRI separately 6 months apart, and 1-12 months later both scans simultaneously using standardised modules. Readers recorded presence/absence of SpA and their level of confidence in this conclusion on a 0-10 scale (0=definitely not; 10=definite). We analysed differences between SIJ...... MRI versus spine MRI alone, and SIJ MRI alone versus combined MRI, descriptively by the number/percentage of subjects according to the mean of four readers. RESULTS: In cohorts A/B, 15.8%/24.2% of patients with nr-axSpA having a negative SIJ MRI were reclassified as being positive for SpA by global...... evaluation of combined scans. However, 26.8%/11.4% of non-specific back pain controls and 17.5% of healthy volunteers with a negative SIJ MRI were falsely reclassified as having SpA by combined MRI. Low confidence in a diagnosis of SpA by SIJ MRI increased to high confidence by combined MRI in 6.6%/7.3% of...

  18. Study of axial magnetic effect

    International Nuclear Information System (INIS)

    The Axial Magnetic Effect manifests itself as an equilibrium energy flow of massless fermions induced by the axial (chiral) magnetic field. Here we study the Axial Magnetic Effect in the quenched SU(2) lattice gauge theory with massless overlap fermions at finite temperature. We numerically observe that in the low-temperature hadron phase the effect is absent due to the quark confinement. In the high-temperature deconfinement phase the energy flow is an increasing function of the temperature which reaches the predicted asymptotic T2 behavior at high temperatures. We find, however, that energy flow is about one order of magnitude lower compared to a theoretical prediction

  19. Characterization of Multiflux Axial Compressors

    International Nuclear Information System (INIS)

    In the present work the results of analytical models of performance are compared with experimental data acquired in the multi flux axial compressor test facility, built in The Pilcaniyeu Technological Complex for the SIGMA project.We describe the experimental circuit and the data of the dispersion inside the axial compressor obtained using a tracer gas through one of the annular inlets.The attained results can be used to validate the design code for the multi flux axial compressors and SIGMA industrial plant

  20. Axial gap rotating electrical machine

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  1. Estimation of the sensitivity and specificity of ASAS criteria for peripheral spondyloarthritis in patients with early psoriatic arthritis

    Directory of Open Access Journals (Sweden)

    E. Yu. Loginova

    2015-01-01

    Full Text Available Objective: to estimate the sensitivity and specificity of ASAS (Assessment of Spondyloarthritis International Society criteria for peripheral spondyloarthritis (SpA in patients with early psoriatic arthritis (ePsA.Subjects and methods. Examinations was made in 45 patients (17 men and 28 women with ePsA meeting the CASPAR (ClASsification criteria for Psoriatic ARthritis criteria (mean age, 37 years; disease duration, 1 year and in 20 patients (9 men and 11 women with signs of peripheral SpA meeting the ESSG (European Spondyloarthropathy Study Group criteria (mean age, 23 years; disease duration, 2.25 years; control group. The investigators estimated 78/76 tender/swollen joints and enthuses using MASES (Maastricht Ankylosing Spondylitis Enthesitis Score and assessed the presence of inflammatory spinal pain according to the ASAS criteria, psoriasis, uveitis, inflammatory bowel diseases, genitourinary and/or enteric infections, and a family history of SpA. They also performed X-ray studies of the hand and distal portions of the foot and pelvis and graded sacroilitis using the Kellgren scores. HLA-B27, C-reactive protein, and erythrocyte sedimentation rate were determined. The sensitivity/specificity, likelihood ratios, and clinical value of criteria were calculated.Results. 41/4 and 31/14 patents with ePsA met/unmet Criteria Sets I and II. The sensitivity/specificity of Sets I and II was 91.1/10% and 68.8/95%, respectively. One patient with ePsA and two patients in the control group did not meet one of the sing sets. The total sensitivity/specificity was 97.8/10%. In the control group, the sensitivity/specificity of Sets I and II was 91.1/100% and 68.8/100%, respectively. For ePsA, the positive likelihood ratio proved to be high for Set II (13.78% and low for Set I (1.01.Conclusion. ASAS Criteria Set I for peripheral SpA is of low value in identifying ePsA and Sign Set II shows a high value in diagnosing ePsA as it includes the major clinical

  2. Vectorial versus axial goldstone bosons

    International Nuclear Information System (INIS)

    The Yukawa interactions of fermions with Goldstone bosons are given in closed form for an arbitrary renormalizable field theory to all orders of perturbation theory or for a general effective Lagrangian. Although the diagonal couplings are always pseudoscalar there is an important difference between spontaneously broken vector and axial-vector global symmetries. Compared to the axial case, the diagonal douplings of 'vectorial' Goldstone bosons to charged fermions are suppressed by mixing angles or appear only via radiative corrections involving gauge fields. This general result may be relevant for the problem of flavour symmetry breaking in composite models. (Author)

  3. Simulation of an Axial Vircator

    CERN Document Server

    Tikhomirov, V V

    2013-01-01

    An algorithm of particle-in-cell simulations is described and tested to aid further the actual design of simple vircators working on axially symmetric modes. The methods of correction of the numerical solution, have been chosen and jointly tested, allow the stable simulation of the fast nonlinear multiflow dynamics of virtual cathode formation and evolution, as well as the fields generated by the virtual cathode. The selected combination of the correction methods can be straightforwardly generalized to the case of axially nonsymmetric modes, while the parameters of these correction methods can be widely used to improve an agreement between the simulation predictions and the experimental data.

  4. Increased plasma levels of IL-21 and IL-23 in spondyloarthritis are not associated with clinical and MRI findings

    DEFF Research Database (Denmark)

    Andersen, Thomas; Rasmussen, Tue Kruse; Hvid, Malene; Holm, Christian Kanstrup; Madsen, Karen Berenth; Jurik, Anne Grethe; Hokland, Marianne; Stengaard-Pedersen, Kristian; Schiøttz-Christensen, Berit; Deleuran, Bent Winding

    2010-01-01

    We have investigated the role of the Th17-related cytokines interleukin-17A (IL-17A), IL-21, and IL-23 in spondyloarthritis (SpA) by examining their association with disease activity and magnetic resonance imaging (MRI) findings in patients with SpA (n = 80). Furthermore, to investigate the...... cellular origins of the cytokines, paired mononuclear cells from blood and synovial fluid were examined for the expression of IL-17A, IL-21, and IL-23R using multicolor flow cytometry. Both IL-21 and IL-23 levels were increased in plasma from SpA patients compared with healthy volunteers (P < 0.......05), whereas IL-17A was not. A significant correlation was observed between individual levels of IL-21 and IL-23 (r = 0.7, P < 0.001). No association between individual levels of IL-17A, IL-21, and IL-23 with C-reactive protein (CRP), MRI changes, and clinical scoring (BASMI, BASFI, and BASDAI) were observed...

  5. Axial structure of the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Veronique Bernard; Latifa Elouadrhiri; Ulf-G Meissner

    2002-01-01

    We review the current status of experimental and theoretical understanding of the axial nucleon structure at low and moderate energies. Topics considered include (quasi)elastic (anti)neutrino-nucleon scattering, charged pion electroproduction off nucleons and ordinary as well as radiative muon capture on the proton.

  6. Axially symmetric rotating traversable wormholes

    CERN Document Server

    Kuhfittig, P K F

    2003-01-01

    This paper generalizes the static and spherically symmetric traversable wormhole geometry to a rotating axially symmetric one with a time-dependent angular velocity by means of an exact solution. It was found that the violation of the weak energy condition, although unavoidable, is considerably less severe than in the static spherically symmetric case. The radial tidal constraint is more easily met due to the rotation. Similar improvements are seen in one of the lateral tidal constraints. The magnitude of the angular velocity may have little effect on the weak energy condition violation for an axially symmetric wormhole. For a spherically symmetric one, however, the violation becomes less severe with increasing angular velocity. The time rate of change of the angular velocity, on the other hand, was found to have no effect at all. Finally, the angular velocity must depend only on the radial coordinate, confirming an earlier result.

  7. View of the Axial Field Spectrometer

    CERN Multimedia

    1980-01-01

    The Axial Field Spectrometer, with the vertical uranium/scintillator calorimeter and the central drift chamber retracted for service. One coil of the Open Axial Field Magnet is just visible to the right.

  8. Simulation of an Axial Vircator

    OpenAIRE

    Tikhomirov, V. V.; Siahlo, S. E.

    2013-01-01

    An algorithm of particle-in-cell simulations is described and tested to aid further the actual design of simple vircators working on axially symmetric modes. The methods of correction of the numerical solution, have been chosen and jointly tested, allow the stable simulation of the fast nonlinear multiflow dynamics of virtual cathode formation and evolution, as well as the fields generated by the virtual cathode. The selected combination of the correction methods can be straightforwardly gene...

  9. Distinctive radiological features of small hand joints in rheumatoid arthritis and seronegative spondyloarthritis demonstrated by contrast-enhanced (Gd-DTPA) magnetic resnance imaging

    International Nuclear Information System (INIS)

    A series of patients with clinically early inflammatory joint disease due to rheumatoid arthritis, psoriatic arthritis and Reiter's syndrome were examined by plain film radiography and magnetic resonance imaging (MRI). The spin echo T1-weighted precontrast, T2-weighted, and, especially, T1-weighted postcontrast images demonstrated distinct differences in the distribution of inflamatory changes, both within and adjacent to involved small hand joints. Two major subtypes of inflammatory arthritis were shown, thus providing a specific differential diagnosis between rheumatoid arthritis and some patients with seronegative spondyloarthritis. In particular, all the patients with Reiter's syndrome who were studied, and half of those with psoriatic arthritis, had a distinctive pattern of extra-articular desease involvement. The need for a new classification of clinical subsets in psoriatic arthritis has been recently suggested. The present findings suggest that magnetic resonance imaging could be useful in such a reclassification of seronegative spondyloarthritis, as well as offering considerable potential for a reappraisal of pathogenesis and therapy. In this series, it was also noted that juxta-articular osteoporosis on plain film did not correlate with bone marrow oedema on MRI. Hence the aetiology of this common radiographic finding also merits further consideration. (orig.)

  10. Design and experimental investigations of a new type of casing treatment for an axial flow compressor

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, I.; Lu, X. [Chinese Academy of Sciences Beijing (China). Institute of Engineering Thermophysics

    2006-07-01

    A new type of bend skewed groove casing treatment was designed on the basis of the test results of the axial skewed groove casing treatment. The influences of utilizing it on an isolated axial-flow rotor, as well as comparisons between it and axial skewed groove, have been investigated experimentally. The effects on overall performance of the axial chord of the rotor exposed to the treated area have been examined, and the ideal axial position of the casing treatment relative to the rotor leading edge was found. For the tested rotor with the new casing treatment, experimental results showed that significant improvements in stall margin were observed without efficiency penalty (in some axial locations) at two different speeds. Compared with the axial skewed groove casing treatment, the new treated casing at the axial exposure does not increase the secondary circulation in the radial-circumferential plane based on x-wire, hot-wire measurements under the operating conditions near peak efficiency. This can be considered to be one of many factors that keep the rotor efficiency identical. (author)

  11. Axial Force at the Vessel Bottom Induced by Axial Impellers

    OpenAIRE

    I. Fořt; P. Hasal; A. Paglianti; F. Magelli

    2008-01-01

    This paper deals with the axial force affecting the flat bottom of a cylindrical stirred vessel. The vessel is equipped with four radial baffles and is stirred with a four 45° pitched blade impeller pumping downwards. The set of pressure transducers is located along the whole radius of the flat bottom between two radial baffles. The radial distribution of the dynamic pressures indicated by the transducers is measured in dependence on the impeller off-bottom clearance and impeller speed.It fol...

  12. Strange axial-vector mesons

    International Nuclear Information System (INIS)

    The strange axial-vector mesons K1 (1270) and K1 (1400) are reanalyzed in the light of the updated experimental information and compared with the recent result on the Kππ production in τ decay. The mixing angle between the strange mesons of 3P1 and 1P1 is determined by the partial decay rates, and, independently, by the masses. They lead to θK∼33 degree or 57 degree. The observed K1 (1400) production dominance in the τ decay favors θK∼33 degree. Flavor-SU(3) breaking of 20% or so in the production amplitudes can explain quantitatively the observed production ratio

  13. Field-Dependent BRS Tranformations and Correct Prescription for $1/(n.k)^{p}$-Type Singularities in Axial Gauges

    CERN Document Server

    Misra, A

    2000-01-01

    The axial-gauge boson propagator contains 1/(n.k)^p-type singularities. These singularities have generally been treated by inventing prescriptions for them. We propose an alternative procedere for treating these singularities in the path-integral formalism using the known way of treating the 1/k^{2n}-type singularities in Lorentz-type gauges. For this purpose we use a finite field-dependent BRS transformation that inerpolates between the Lorentz and axial-type gauges. We arrive at the \\epsilon-dependent tree propagator in axial-type gauges.

  14. PWR AXIAL BURNUP PROFILE ANALYSIS

    International Nuclear Information System (INIS)

    The purpose of this activity is to develop a representative ''limiting'' axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the ''end-effect''. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package. The scope of this calculation covers an initial enrichment range of 3.0 through 5.0 wt% U-235 and a burnup range of 10 through 50 GWd/MTU. This activity supports the validation of the process for ensuring conservative generation of spent fuel isotopics with respect to criticality safety applications, and the use of burnup credit for commercial spent nuclear fuel. The intended use of these results will be in the development of PWR waste package loading curves, and applications involving burnup credit. Limitations of this evaluation are that the limiting profiles are only confirmed for use with the B andW 15 x 15 fuel assembly design. However, this assembly design is considered bounding of all other typical commercial PWR fuel assembly designs. This calculation is subject to the Quality Assurance Requirements and Description (QARD) because this activity supports investigations of items or barriers on the Q-list (YMP 2001)

  15. PWR AXIAL BURNUP PROFILE ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Acaglione

    2003-09-17

    The purpose of this activity is to develop a representative ''limiting'' axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the ''end-effect''. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package. The scope of this calculation covers an initial enrichment range of 3.0 through 5.0 wt% U-235 and a burnup range of 10 through 50 GWd/MTU. This activity supports the validation of the process for ensuring conservative generation of spent fuel isotopics with respect to criticality safety applications, and the use of burnup credit for commercial spent nuclear fuel. The intended use of these results will be in the development of PWR waste package loading curves, and applications involving burnup credit. Limitations of this evaluation are that the limiting profiles are only confirmed for use with the B&W 15 x 15 fuel assembly design. However, this assembly design is considered bounding of all other typical commercial PWR fuel assembly designs. This calculation is subject to the Quality Assurance Requirements and Description (QARD) because this activity supports investigations of items or barriers on the Q-list (YMP 2001).

  16. Mass Effect on Axial Charge Dynamics

    CERN Document Server

    Guo, Er-dong

    2016-01-01

    We studied effect of finite quark mass on the dynamics of axial charge using the D3/D7 model in holography. The mass term in axial anomaly equation affects both the fluctuation (generation) and dissipation of axial charge. We studied the dependence of the effect on quark mass and external magnetic field. For axial charge generation, we calculated the mass diffusion rate, which characterizes the helicity flipping rate. The rate is a non-monotonous function of mass and can be significantly enhanced by the magnetic field. The diffusive behavior is also related to a divergent susceptibility of axial charge. For axial charge dissipation, we found that in the long time limit, the mass term dissipates all the charge effectively generated by parallel electric and magnetic fields. The result is consistent with a relaxation time approximation. The rate of dissipation through mass term is a monotonous increasing function of both quark mass and magnetic field.

  17. Axial Vector $Z'$ and Anomaly Cancellation

    CERN Document Server

    Ismail, Ahmed; Tsao, Kuo-Hsing; Unwin, James

    2016-01-01

    Whilst the prospect of new $Z'$ gauge bosons with only axial couplings to the Standard Model (SM) fermions is widely discussed, examples of anomaly-free renormalisable models are lacking in the literature. We look to remedy this by constructing several motivated examples. Specifically, we consider axial vectors which couple universally to all SM fermions, as well as those which are generation-specific, leptophilic, and leptophobic. Anomaly cancellation typically requires the presence of new coloured and charged chiral fermions, and we argue that the masses of these new states must generally be comparable to that of the axial vector. Finally, an axial vector mediator could provide a portal between SM and hidden sector states, and we also consider the possibility that the axial vector couples to dark matter. If the dark matter relic density is set due to freeze-out via the axial vector, this strongly constrains the parameter space.

  18. Axial velocity in decaying swirl flow

    Science.gov (United States)

    Algifri, A. H.; Bhardwaj, R. K.; Rao, Y. V. N.

    1988-09-01

    Experiments were carried out on turbulent swirling flow with variable initial swirl at different flow rates to study the effect of swirl on axial velocity. A correlation was made between the defect in the swirling flow axial velocity and the swirl number which locally defines the swirl intensity. An expression which can be used to predict the axial velocity distribution of turbulent swirling flow in a pipe is presented.

  19. Sensorless Control of Axial Magnetic Bearings

    Science.gov (United States)

    Atsumo, Daichi; Yoshida, Toshiya; Ohniwa, Katsumi

    This paper describes a sensorless control method of axial active magnetic bearings (AMBs). At high frequencies, inductance of the axial electromagnets is hardly dependent on the airgap because of the eddy current effects of the non-laminated core. Therefore the carrier frequency should be 3 kHz below to improve the sensitivity to the airgap. In the experiment, Sensorless controll of the axial AMBs have been achieved.

  20. Axial asymmetry in the IVBM

    International Nuclear Information System (INIS)

    The dynamical symmetry limit of the two-fluid Interacting Vector Boson Model (IVBM), defined through the chain Sp(12,R) contains U(3,3) contains Up(3) x Un(3) contains SU*(3) contains SO(3), is considered and applied for the description of nuclear collective spectra exhibiting axially asymmetric features. The effect of the introduction of a Majorana interaction to the SU*(3) model Hamiltonian on the γ-band energies is studied. The theoretical predictions are compared with the experimental data for 192Os, 190Os, and 112Ru isotopes. It is shown that by taking into account the full symplectic structures in the considered dynamical symmetry of the IVBM, the proper description of the energy spectra and the γ-band energy staggering of the nuclei under considerations can be achieved. The obtained results show that the potential energy surfaces for the following two nuclei 192Os and 112Ru, possess almost γ-flat potentials with very shallow triaxial minima, suggesting a more complex and intermediate situation between γ-rigid and γ-unstable structures. Additionally, the absolute B(E2) intraband transition probabilities between the states of the ground-state band and γ band, as well as the B(M1) interband transition probabilities between the states of the ground and γ bands for the two nuclei 192Os and 190Os are calculated and compared with experiment and for the B(E2) values with the predictions of some other collective models incorporating the γ-rigid or γ-unstable structures. The obtained results agree well with the experimental data and reveal the relevance of the used dynamical symmetry of IVBM in the description of nuclei exhibiting axially asymmetric features in their spectra. (orig.)

  1. Effective quantum number for axially symmetric problems

    OpenAIRE

    Trunov, N. N.

    2014-01-01

    We generalize the universal effective quantum number introduced earlier for centrally symmetric problems. The proposed number determines the semiclassical quantization condition for axially symmetric potentials.

  2. Origin of axial current in scyllac

    International Nuclear Information System (INIS)

    The origin of the axial current observed in Scyllac (a high beta stellarator experiment) is discussed. A shaped coil and/or helical winding produce rotational transform which links magnetic lines of force to the plasma column and the axial current is induced electromagnetically. This phenomenon is inherent in a pulsed high-beta stellarator. The rotational transform produced by the induced axial current is much smaller than that associated with the l = 1, 0 equilibrium fields. The effect of the axial current on the equilibrium and stability of the plasma column is thus small. It is also shown that the magnetic field shear near a plasma surface is very strong

  3. Indirect and direct costs of treating patients with ankylosing spondylitis in the Brazilian public health system

    Directory of Open Access Journals (Sweden)

    Valderilio Feijó Azevedo

    2016-04-01

    Full Text Available ABSTRACT Introduction: Patients with Ankylosing Spondylitis (AS require a team approach from multiple professionals, various treatment modalities for continuous periods of time, and can lead to the loss of labour capacity in a young population. So, it is necessary to measure its socio-economic impact. Objectives: To describe the use of public resources to treat AS in a tertiary hospital after the use of biological medications was approved for treating spondyloarthritis in the Health Public System, establishing approximate values for the direct and indirect costs of treating this illness in Brazil. Material and methods: 93 patients selected from the ambulatory spondyloarthritis clinic at the Hospital de Clínicas of the Federal University of Paraná between September 2011 and September 2012 had their direct costs indirect treatment costs estimation. Results: 70 patients (75.28% were male and 23 (24.72% female. The mean age was 43.95 years. The disease duration was calculated based on the age of diagnosis and the mean was 8.92 years (standard deviation: 7.32; 63.44% were using anti-TNF drugs. Comparing male and female patients the mean BASDAI was 4.64 and 5.49 while the mean BASFI was 5.03 and 6.35 respectively. Conclusions: The Brazilian public health system's spending related to ankylosing spondylitis has increased in recent years. An important part of these costs is due to the introduction of new, more expensive health technologies, as in the case of nuclear magnetic resonance and, mainly, the incorporation of anti-TNF therapy into the therapeutic arsenal. The mean annual direct and indirect cost to the Brazilian public health system to treat a patient with ankylosing spondylitis, according to our findings, is US$ 23,183.56.

  4. Correct Treatment of $1/(\\eta-k)^{p}$ Singularities in the Axial Gauge Propagator

    CERN Document Server

    Joglekar, S D; Joglekar, Satish D.

    2000-01-01

    The propagators in axial-type, light-cone and planar gauges contain 1/(\\eta\\cdot k)^p-type singularities. These singularities have generally been treated by inventing prescriptions for them. In this work, we propose an alternative procedure for treating these singularities in the path integral formalism using the known way of treating the singularities in Lorentz gauges. To this end, we use a finite field-dependent BRS transformation that interpolates between Lorentz-type and the axial-type gauges. We arrive at the singularity structure of the propagator and find that the axial gauge propagator so constructed has {\\it no} spurious poles (for real $k$). It however has a complicated structure in a small region near $\\eta\\cdot k=0$. We show how this complicated structure can effectively be replaced by a much simpler propagator.

  5. Analysis of IL-17+ cells in facet joints of patients with spondyloarthritis suggests that the innate immune pathway might be of greater relevance than the Th17-mediated adaptive immune response

    OpenAIRE

    Appel, Heiner; Maier, René; Wu, Peihua; Scheer, Rebecca; Hempfing, Axel; Kayser, Ralph; Thiel, Andreas; Radbruch, Andreas; Loddenkemper, Christoph; Sieper, Joachim

    2011-01-01

    Introduction In this study, we analysed the number of IL-17+ cells in facet joints, in the peripheral blood (PB) and synovial fluid (SF) of spondyloarthritis (SpA) patients and compared these results with those of patients with other rheumatic diseases and controls. Methods Immunohistochemical analysis of IL-17+ cells was performed in facet joints of 33 ankylosing spondylitis (AS) patients and compared with data from 20 osteoarthritis (OA) patients. The frequency of IL-17+CD4+ T cells in PB a...

  6. Axial force measurement for esophageal function testing.

    Science.gov (United States)

    Gravesen, Flemming H; Funch-Jensen, Peter; Gregersen, Hans; Drewes, Asbjørn Mohr

    2009-01-14

    The esophagus serves to transport food and fluid from the pharynx to the stomach. Manometry has been the "golden standard" for the diagnosis of esophageal motility diseases for many decades. Hence, esophageal function is normally evaluated by means of manometry even though it reflects the squeeze force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe with combined axial force and manometry recordings showed that axial force amplitude increased by 130% in contrast to an increase of 30% using manometry. Using axial force in combination with manometry provides a more complete picture of esophageal motility, and the current paper outlines the advantages of using this method. PMID:19132762

  7. Axial force measurement for esophageal function testing

    Institute of Scientific and Technical Information of China (English)

    Flemming H Gravesen; Peter Funch-Jensen; Hans Gregersen; Asbjφrn Mohr Drewes

    2009-01-01

    The esophagus serves to transport food and fluid from the pharynx to the stomach. Manometry has been the "golden standard" for the diagnosis of esophageal motility diseases for many decades. Hence, esophageal function is normally evaluated by means of manometry even though it reflects the squeeze force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe with combined axial force and manometry recordings showed that axial force amplitude increased by 130% in contrast to an increase of 30% using manometry. Using axial force in combination with manometry provides a more complete picture of esophageal motility, and the current paper outlines the advantages of using this method.

  8. Axial Anomaly and the Triality Symmetry of Octonion

    International Nuclear Information System (INIS)

    With an assumption that in the Yang-Mills Lagrangian, a left-handed fermion and a right-handed fermion both expressed as the quaternion makes an octonion, and the gauge field can be treated as self-dual, we calculate the axial current and two vector currents triangle diagram of Bardeen, which yields the contribution of the axial anomaly. The octonion possesses the triality symmetry, and there are 5 symmetry operations Gij and Gijk (ijk = 123), in which mixing of spinors and vectors occur. G23 does not mix vectors and spinors, but mismatch of the spinor and vector fields occurs. Hence, electro magnetic (EM) wave emitted from galaxies transformed by the five transformations would not be detected by EM detectors in our galaxy, and the source would be regarded as dark matter. The axial anomaly appears as a reflection of the symmetry of the matter field and not as a reflection of the symmetry of the pure vacuum, which is consistent with recent arguments on condensates and confinement. (author)

  9. Axial length variability in cataract surgery

    International Nuclear Information System (INIS)

    To determine the mean axial length and biometric measures in patients undergoing cataract surgery and further compare the variability of axial length between the gender and with age. Study Design: Cross-sectional observational study. Place and Duration of Study: Eye Unit I, Department of Ophthalmology, Liaquat University of Medical and Health Sciences, Hyderabad, Pakistan from January 2010 to December 2012. Methodology: All patients referred for cataract surgery were assessed. The study included 886 eyes which were straightforward cataract cases with no other ocular problem. The data was collected for axial length, keratometric values and Intra-Ocular Lens (IOL) power prior to cataract surgery. The collected data was then analyzed using SPSS version 19 for windows software. Results: Gender based comparison showed significant difference in age, axial length, keratometric values and IOL power between the two groups (p=0.000). 86% of the eyes had an axial length between 21.00 mm and 23.99 mm. In univariate analysis there was significant (p=0.000) relation between overall age and axial length. The keratometric values ranged between 36.75 D and 52.50 D. Majority of the IOL powers ranged between 20.00 D and 23.00 D. Conclusion: The mean axial length of patients undergoing cataract surgery was 22.96 +- 1.04 mm, was comparable to Indian and Chinese population but shorter than the Western population. Females had shorter axial lengths, similar to other studies. Axial length was positively associated with age among the females, the cause of which is yet to be determined. (author)

  10. New Anomaly of the Axial-Vector Current

    Institute of Scientific and Technical Information of China (English)

    HE Han-Xin

    2001-01-01

    By computing the axial-vector current operator equation, we find the anomalous axial-vector curl equation besides the well-known anomalous axial-vector divergence equation (the Adler-Bell-Jackiw anomaly) and discuss its implication.``

  11. Axial Thermal Rotation of Slender Rods

    Science.gov (United States)

    Li, Dichuan; Fakhri, Nikta; Pasquali, Matteo; Biswal, Sibani Lisa

    2011-05-01

    Axial rotational diffusion of rodlike polymers is important in processes such as microtubule filament sliding and flagella beating. By imaging the motion of small kinks along the backbone of chains of DNA-linked colloids, we produce a direct and systematic measurement of axial rotational diffusivity of rods both in bulk solution and near a wall. The measured diffusivities decrease linearly with the chain length, irrespective of the distance from a wall, in agreement with slender-body hydrodynamics theory. Moreover, the presence of small kinks does not affect the chain’s axial diffusivity. Our system and measurements provide insights into fundamental axial diffusion processes of slender objects, which encompass a wide range of entities including biological filaments and linear polymer chains.

  12. Juvenile Spondyloarthritis: An Overview

    Science.gov (United States)

    ... enthesitis plus at least one of the following: lower back pain or sacroiliac tenderness, HLA-B27 positivity, a parent ... B27 positive never develop JSpA. The presence of lower back pain is not as helpful in JSpA as in ...

  13. Juvenile Spondyloarthritis: An Overview

    Science.gov (United States)

    ... fingers or toes), acute and painful eye inflammation, HLA-B27 positivity, inflammatory back pain, and sacroiliitis. The term ... the following: lower back pain or sacroiliac tenderness, HLA-B27 positivity, a parent with a history of SpA, ...

  14. Spondyloarthritis: A Gouty Display

    OpenAIRE

    Gongidi, Preetam; Gough-Fibkins, Shawn

    2010-01-01

    Gout is a systemic, metabolic disease that typically affects the peripheral joints. We describe an unusual presentation of gout affecting the facet joints and costovertebral joints in the thoracic and lumbar spine. A 54-year old man presents to the emergency department with increasing swelling and pain at the left elbow for one week and difficulty ambulating. The imaging work-up included plain radiographs of the left elbow, left wrist, and chest with subsequent admission for possible septic a...

  15. Computer axial tomography in geosciences

    International Nuclear Information System (INIS)

    Computer Axial Tomography (CAT) is one of the most adequate non-invasive techniques for the investigation of the internal structure of a large category of objects. Initially designed for medical investigations, this technique, based on the attenuation of X- or gamma-ray (and in some cases neutrons), generates digital images which map the numerical values of the linear attenuation coefficient of a section or of the entire volume of the investigated sample. Shortly after its application in medicine, CAT has been successfully used in archaeology, life sciences, and geosciences as well as for the industrial materials non-destructive testing. Depending on the energy of the utilized radiation as well as on the effective atomic number of the sample, CAT can provide with a spatial resolution of 0.01 - 0.5 mm, quantitative as well as qualitative information concerning local density, porosity or chemical composition of the sample. At present two types of axial Computer Tomographs (CT) are in use. One category, consisting of medical as well as industrial CT is equipped with X-ray tubes while the other uses isotopic gamma-ray sources. CT provided with intense X-ray sources (equivalent to 12-15 kCi or 450-550 TBq) has the advantage of an extremely short running time (a few seconds and even less) but presents some disadvantages known as beam hardening and absorption edge effects. These effects, intrinsically related to the polychromatic nature of the X-rays generated by classical tubes, need special mathematical or physical corrections. A polychromatic X-ray beam can be made almost monochromatic by means of crystal diffraction or by using adequate multicomponent filters, but these devices are costly and considerably diminish the output of X-ray generators. In the case of CT of the second type, monochromatic gamma-rays generated by radioisotopic sources, such as 169 Yb (50.4 keV), 241 Am (59 keV), 192 Ir (310.5 and 469.1 keV ) or 137 Cs (662.7 keV), are used in combination with

  16. Nonperturbative features of the axial current

    CERN Document Server

    Kopeliovich, B Z; Siddikov, M

    2013-01-01

    In this paper we study the nonperturbative structure of the axial current and evaluate the two-point distribution amplitudes $\\int d\\xi\\, e^{-iq...\\xi}$ in the framework of the instanton vacuum model in the leading order in $\\mathcal{O}(N_{c})$. We perform a direct numerical test of the relations between the axial current and the pion distribution amplitudes, imposed by PCAC, and found excellent agreement.

  17. Axial Vircator for Electronic Warfare Applications

    OpenAIRE

    L. Drazan; R. Vrana

    2009-01-01

    This paper deals with a high power microwave generator with virtual cathode – vircator in axial release for electronic warfare applications. The classification of directed energy weapons microwave (DEWM) is introduced together with basic block diagrams of a particular class of DEWM. In the paper, methods for designing vircator pulsed power supply, axial vircator structure, measurement methods and experimental results are presented. The vircator in electromagnetic ammunition is powered b...

  18. Nonperturbative Aspects of Axial Vector Vertex

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; CHEN Xiang-Song; WANG Fan; CHANG Chao-Hsi; ZHAO En-Guang

    2002-01-01

    It is shown how the axial vector current of current quarks is related to that of constituent quarks within the framework of the global color symmetry model.Gluon dressing of the axial vector vertex and the quark self-energy functions are described by the inhomogeneous Bethe-Salpeter equation in the ladder approximation and the Schwinger Dyson equation in the rainbow approximation,respectively.

  19. An Unbroken Axial Vector Current Conservation Law

    CERN Document Server

    Sharafiddinov, Rasulkhozha S

    2015-01-01

    The mass, energy and momentum of the neutrino of a true flavor have an axial-vector nature. As a consequence, the left-handed truly neutral neutrino in an axial-vector field of emission can be converted into a right-handed one and vice versa. This predicts the unidenticality of masses, energies and momenta of neutrinos of the different components. Recognizing such a difference in masses, energies, momenta and accepting that the left-handed axial-vector neutrino and the right-handed antineutrino of true neutrality refer to long-lived C-odd leptons, and the right-handed truly neutral neutrino and the left-handed axial-vector antineutrino are of short-lived fermions of C-oddity, we would write a new CP-even Dirac equation taking into account the flavor symmetrical axial-vector mass, energy and momentum matrices. Their presence explains the spontaneous mirror symmetry violation, confirming that an axial-vector current conservation law has never violated. They reflect the availability of a mirror Minkowski space i...

  20. Magnetic resonance imaging of the sacroiliac joints in patients with suspected spondyloarthritis. Comparison of turbo spin-echo and gradient-echo sequences for the detection of structural alterations; MRT-Bildgebung der Sakroiliakalgelenke bei Verdacht auf Spondyloarthritis. Vergleich von Turbospinecho- und Gradientenechosequenzen zum Nachweis struktureller Veraenderungen

    Energy Technology Data Exchange (ETDEWEB)

    Dornia, C.; Hoffstetter, P. [Universitaetsklinikum Regensburg (Germany). Inst. fuer Roentgendiagnostik; Asklepios Klinikum, Bad Abbach (Germany). Inst. fuer Roentgendiagnostik; Fleck, M. [Universitaetsklinikum Regensburg (Germany). Klinik fuer Innere Medizin I; Asklepios Klinikum, Bad Abbach (Germany). Klinik fuer Rheumatologie und Klinische Immunologie; Hartung, W. [Asklepios Klinikum, Bad Abbach (Germany). Klinik fuer Rheumatologie und Klinische Immunologie; Niessen, C.; Stroszczynski, C. [Universitaetsklinikum Regensburg (Germany). Inst. fuer Roentgendiagnostik

    2015-02-15

    Magnetic resonance imaging (MRI) is the method of choice for the evaluation of spondyloarthritis (SpA). According to the guidelines of the Assessment of Spondyloarthritis International Society (ASAS) and Outcome Measures in Rheumatology (OMERACT), MRI findings in SpA of the spine and the sacroiliac joints (SIJ) are classified as inflammatory and structural alterations. Modern gradient-echo sequences (GRE) are recommended for optimized detection of structural alterations of the SIJ. We assess the benefit of GRE in the detection of structural alterations of the SIJ in comparison to conventional turbo spin-echo sequences (TSE). Retrospective study of 114 patients who received MRI of the SIJ for the evaluation of SpA. Structural alterations of the SIJ were assessed by two blinded readers separately for T1 TSE and T2{sup *} GRE. The findings were classified according to a previously published chronicity score separately for both sides and sequences. Interobserver reliability was calculated with Cohen's Kappa, and the significance of findings was assessed with the Wilcoxon test. P-values < 0.05 were required for statistical significance. 68 of 114 (60%) patients showed SpA-typical findings of the SIJ. The average chronicity score for GRE (score 3.3) was significantly higher than for TSE (score 2.6), p=0.001. The Kappa-values for the interobserver reliability were 0.86-0.90 without any statistically significant differences between both sides and sequences. Both T1 TSE and T2{sup *} GRE showed a high interobserver reliability in the detection of structural alterations in patients with SpA. However, T2{sup *} GRE detected significantly more structural alterations than T1 TSE and should be an integral part of a modern MRI protocol for the diagnostic workup of patients with suspected SpA.

  1. Growth-induced axial buckling of a slender elastic filament embedded in an isotropic elastic matrix

    KAUST Repository

    O'Keeffe, Stephen G.

    2013-11-01

    We investigate the problem of an axially loaded, isotropic, slender cylinder embedded in a soft, isotropic, outer elastic matrix. The cylinder undergoes uniform axial growth, whilst both the cylinder and the surrounding elastic matrix are confined between two rigid plates, so that this growth results in axial compression of the cylinder. We use two different modelling approaches to estimate the critical axial growth (that is, the amount of axial growth the cylinder is able to sustain before it buckles) and buckling wavelength of the cylinder. The first approach treats the filament and surrounding matrix as a single 3-dimensional elastic body undergoing large deformations, whilst the second approach treats the filament as a planar, elastic rod embedded in an infinite elastic foundation. By comparing the results of these two approaches, we obtain an estimate of the foundation modulus parameter, which characterises the strength of the foundation, in terms of the geometric and material properties of the system. © 2013 Elsevier Ltd. All rights reserved.

  2. Optimization of residual heat removal pump axial thrust and axial bearing

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, F.

    1996-12-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies.

  3. Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain

    Energy Technology Data Exchange (ETDEWEB)

    Arnbak, Bodil; Jensen, Tue S.; Manniche, Claus [Hospital Lillebaelt, Research Department, Spine Centre of Southern Denmark, Middelfart (Denmark); University of Southern Denmark, Institute of Regional Health Research, Odense C (Denmark); Egund, Niels; Zejden, Anna [Aarhus University Hospital, Department of Radiology, Aarhus C (Denmark); Hoerslev-Petersen, Kim [University of Southern Denmark, Institute of Regional Health Research, Odense C (Denmark); King Christian 10th Hospital for Rheumatic Diseases, Graasten, Graasten (Denmark); Jurik, Anne G. [Hospital Lillebaelt, Research Department, Spine Centre of Southern Denmark, Middelfart (Denmark); University of Southern Denmark, Institute of Regional Health Research, Odense C (Denmark); Aarhus University Hospital, Department of Radiology, Aarhus C (Denmark)

    2016-04-15

    To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. (orig.)

  4. Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain

    International Nuclear Information System (INIS)

    To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. (orig.)

  5. Polarization converters based on axially symmetric twisted nematic liquid crystal.

    Science.gov (United States)

    Ko, Shih-Wei; Ting, Chi-Lun; Fuh, Andy Y-G; Lin, Tsung-Hsien

    2010-02-15

    An axially symmetric twisted nematic liquid crystal (ASTNLC) device, based on axially symmetric photoalignment, was demonstrated. Such an ASTNLC device can convert axial (azimuthal) to azimuthal (axial) polarization. The optical properties of the ASTNLC device are analyzed and found to agree with simulation results. The ASTNLC device with a specific device can be adopted as an arbitrary axial symmetric polarization converter or waveplate for axially, azimuthally or vertically polarized light. A design for converting linear polarized light to axially symmetric circular polarized light is also demonstrated. PMID:20389369

  6. Improving the lattice axial vector current

    CERN Document Server

    Horsley, R; Perlt, H; Rakow, P E L; Schierholz, G; Schiller, A; Zanotti, J M

    2015-01-01

    For Wilson and clover fermions traditional formulations of the axial vector current do not respect the continuum Ward identity which relates the divergence of that current to the pseudoscalar density. Here we propose to use a point-split or one-link axial vector current whose divergence exactly satisfies a lattice Ward identity, involving the pseudoscalar density and a number of irrelevant operators. We check in one-loop lattice perturbation theory with SLiNC fermion and gauge plaquette action that this is indeed the case including order $O(a)$ effects. Including these operators the axial Ward identity remains renormalisation invariant. First preliminary results of a nonperturbative check of the Ward identity are also presented.

  7. Axial instability of rotating relativistic stars

    CERN Document Server

    Friedman, J L; Friedman, John L.; Morsink, Sharon M.

    1998-01-01

    Perturbations of rotating relativistic stars can be classified by their behavior under parity. For axial perturbations (r-modes), initial data with negative canonical energy is found with angular dependence $e^{im\\phi}$ for all values of $m\\geq 2$ and for arbitrarily slow rotation. This implies instability (or marginal stability) of such perturbations for rotating perfect fluids. This low $m$-instability is strikingly different from the instability to polar perturbations, which sets in first for large values of $m$. The timescale for the axial instability appears, for small angular velocity $\\Omega$, to be proportional to a high power of $\\Omega$. As in the case of polar modes, viscosity will again presumably enforce stability except for hot, rapidly rotating neutron stars. This work complements Andersson's numerical investigation of axial modes in slowly rotating stars.

  8. The axial distribution of reactivity coefficients

    International Nuclear Information System (INIS)

    The purpose of the present work is to investigate the correlation of the axial distributions of the different reactivity coefficients with the neutron flux and the neutron flux squared. Calculations were carried out for the Zion Unit 2 PWR. Reactivity coefficients, forward fluxes and adjoint fluxes were all computed and correlations obtained. The core length was divided into 7 axial regions in order to obtain the effect on reactivity in the reactor as a whole of changing the cross sections in each axial region in turn. The parameters chosen for change were coolant density, coolant temperature and fuel temperature. The results appear to bear out our original hypothesis that the reactivity coefficient profiles have a higher positive correlation with the total flux squared profile than with the linear flux profile. (authors). 5 refs., 2 figs

  9. Selection rules and ratios for axial couplings

    CERN Document Server

    Buccella, F; Pugliese, A; Sorace, E

    1972-01-01

    The predictions for the axial couplings following from the use of the mixing operator U(Z), previously introduced to tilt the axial charges of SU/sub 6/ in the physical ones, are studied. The quantum number (-1)/sup L+L3/, where L and L/sub 3/ are the O/sub 3/ angular momentum and its third component, is shown to be conserved. From the properties of Z further predictions can be achieved as the D/F= /sup 3///sub 2/ for the /sup 1///sub 2//sup +/ baryon octet in general agreement with experiment. (14 refs).

  10. Axial Stiffness of Multiwalled Carbon Nanotubes

    OpenAIRE

    Zavalniuk, Vladimir

    2011-01-01

    The axial stiffness of MWCNTs is demonstrated to be determined only by several external shells (usually 3-5 and up to 15 for the extremely large nanotubes and high elongations) what is in a good agreement with experimentally observed inverse relation between the radius and Young modulus (i.e., stiffness) of MWCNTs. This result is a consequence of the van der Waals intershell interaction. The interpolating formula is obtained for the actual axial stiffness of MWCNT as a function of the tube ex...

  11. Axial Vircator for Electronic Warfare Applications

    Directory of Open Access Journals (Sweden)

    L. Drazan

    2009-12-01

    Full Text Available This paper deals with a high power microwave generator with virtual cathode – vircator in axial release for electronic warfare applications. The classification of directed energy weapons microwave (DEWM is introduced together with basic block diagrams of a particular class of DEWM. In the paper, methods for designing vircator pulsed power supply, axial vircator structure, measurement methods and experimental results are presented. The vircator in electromagnetic ammunition is powered by magneto-cumulative generator and in weapons for defense of objects (WDO, it is powered by Marx generator. The possible applications of a vircator in the DEWM area are discussed.

  12. Systemic 7-methylxanthine in retarding axial eye growth and myopia progression: a 36-month pilot study

    OpenAIRE

    Trier, Klaus; Munk Ribel-Madsen, Søren; Cui, Dongmei; Brøgger Christensen, Søren

    2008-01-01

    The adenosine antagonist 7-methylxanthine (7-mx) works against myopia in animal models. In a clinical trial, 68 myopic children (mean age 11.3 years) received either placebo or 7-mx tablets for 12 months. All participants subsequently received 7-mx for another 12 months, after which treatment was stopped. Axial length was measured with Zeiss IOL-Master and cycloplegic refraction with Nikon Retinomax at −6, 0, 12, 24, and 36 months. Axial growth was reduced among children treated with 7-mx for...

  13. On two transverse nonlinear models of axially moving beams

    Institute of Scientific and Technical Information of China (English)

    DING Hu; CHEN LiQun

    2009-01-01

    Nonlinear models of transverse vibration of axially moving beams are computationally investigated. A partial-differential equation is derived from the governing equation of coupled planar motion by omit-ting its longitudinal terms. The model can be reduced to an integro-partial-differential equation by av-eraging the beam disturbed tension. Numerical schemes are respectively presented for the governing equations of coupled planar and the two governing equations of transverse motion via the finite dif-ference method and differential quadrature method under the fixed boundary and the simple support boundary. A steel beam and a copper beam are treated as examples to demonstrate the deviations of the solutions to the two transverse equations from the solution to the coupled equation. The numerical results indicate that the differences increase with the amplitude of vibration and the axial speed. Both models yield almost the same precision results for small amplitude vibration and the inte-gro-partial-differential equation gives better results for large amplitude vibration.

  14. On two transverse nonlinear models of axially moving beams

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Nonlinear models of transverse vibration of axially moving beams are computationally investigated. A partial-differential equation is derived from the governing equation of coupled planar motion by omit- ting its longitudinal terms. The model can be reduced to an integro-partial-differential equation by av- eraging the beam disturbed tension. Numerical schemes are respectively presented for the governing equations of coupled planar and the two governing equations of transverse motion via the finite dif- ference method and differential quadrature method under the fixed boundary and the simple support boundary. A steel beam and a copper beam are treated as examples to demonstrate the deviations of the solutions to the two transverse equations from the solution to the coupled equation. The numerical results indicate that the differences increase with the amplitude of vibration and the axial speed. Both models yield almost the same precision results for small amplitude vibration and the inte- gro-partial-differential equation gives better results for large amplitude vibration.

  15. Knowledge Based Design of Axial Flow Compressor

    Directory of Open Access Journals (Sweden)

    Dinesh kumar.R

    2015-05-01

    Full Text Available In the aerospace industry with highly competitive market the time to design and delivery is shortening every day. Pressure on delivering robust product with cost economy is in demand in each development. Even though technology is older, it is new for each customer requirement and highly non-liner to fit one in another place. Gas turbine is considered one of a complex design in the aircraft system. It involves experts to be grouped with designers of various segments to arrive the best output. The time is crucial to achieve a best design and it needs knowledge automation incorporated with CAD/CAE tools. In the present work an innovative idea in the form of Knowledge Based Engineering for axial compressor is proposed, this includes the fundamental design of axial compressor integrated with artificial intelligence in the form of knowledge capturing and programmed with high level language (Visual Basis.Net and embedded into CATIA v5. This KBE frame work eases out the design and modeling of axial compressor design and produces 3D modeling for further flow simulation with fluid dynamic in Ansys-Fluent. Most of the aerospace components are developed through simulation driven product development and in this case it is established for axial compressor.

  16. The Axial Current in Electromagnetic Interaction

    CERN Document Server

    Cheoun, M K; Cheon, I T; Cheoun, Myung Ki; Cheon, Il-Tong

    1998-01-01

    We discussed the possibility that the charged axial currents of matter fields could be non-conserved in electromagnetic interaction at $O(e) $ order. It means that chiral symmetry is broken explicitly by electromagnetic interaction. This explicit symmetry breaking of chiral symmetry is shown to lead the mass differences between the charged and neutral particles of matter fields.

  17. Constant-axial-intensity nondiffracting beam.

    Science.gov (United States)

    Cox, A J; D'Anna, J

    1992-02-15

    Numerical solutions of the Fresnel diffraction integral with various apodizing filter functions are used to indicate that a so-called nondiffracting beam can be produced that maintains a constant spot size and constant axial intensity over a considerable range, approximately 30 m in our example. PMID:19784285

  18. Axially symmetric SU(3) gravitating skyrmions

    Energy Technology Data Exchange (ETDEWEB)

    Ioannidou, Theodora [Maths Division, School of Technology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)]. E-mail: ti3@auth.gr; Kleihaus, Burkhard [Institut fuer Physik, Universitaet Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany)]. E-mail: kleihaus@theorie.physik.uni-oldenburg.de; Zakrzewski, Wojtek [Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom)]. E-mail: w.j.zakrzewski@durham.ac.uk

    2004-10-21

    Axially symmetric gravitating multi-skyrmion configurations are obtained using the harmonic map ansatz introduced in [J. Math. Phys. 40 (1999) 6353]. In particular, the effect of gravity on the energy and baryon densities of the SU(3) non-gravitating multi-skyrmion configurations is studied in detail.

  19. Axially symmetric SU(3) Gravitating Skyrmions

    CERN Document Server

    Ioannidou, T A; Zakrzewski, W J; Ioannidou, Theodora; Kleihaus, Burkhard; Zakrzewski, Wojtek

    2004-01-01

    Axially symmetric gravitating multi-skyrmion configurations are obtained using the harmonic map ansatz introduced in [1]. In particular, the effect of gravity on the energy and baryon densities of the SU(3) non-gravitating multi-skyrmion configurations is studied in detail.

  20. Axially symmetric SU(3) gravitating skyrmions

    International Nuclear Information System (INIS)

    Axially symmetric gravitating multi-skyrmion configurations are obtained using the harmonic map ansatz introduced in [J. Math. Phys. 40 (1999) 6353]. In particular, the effect of gravity on the energy and baryon densities of the SU(3) non-gravitating multi-skyrmion configurations is studied in detail

  1. Primitive axial algebras of Jordan type

    OpenAIRE

    Hall, J I; Rehren, F; Shpectorov, S.

    2014-01-01

    An axial algebra over the field $\\mathbb F$ is a commutative algebra generated by idempotents whose adjoint action has multiplicity-free minimal polynomial. For semisimple associative algebras this leads to sums of copies of $\\mathbb F$. Here we consider the first nonassociative case, where adjoint minimal polynomials divide $(x-1)x(x-\\eta)$ for fixed $0\

  2. Treating Meningitis

    Science.gov (United States)

    ... David C. Spencer, MD Steven Karceski, MD Treating meningitis Steven Karceski, MD WHAT DID THE AUTHORS STUDY? ... study, “ Dexamethasone and long-term survival in bacterial meningitis, ” Dr. Fritz and his colleagues carefully evaluated 2 ...

  3. Enzalutamide Reduces the Bone Mass in the Axial But Not the Appendicular Skeleton in Male Mice.

    Science.gov (United States)

    Wu, Jianyao; Movérare-Skrtic, Sofia; Börjesson, Anna E; Lagerquist, Marie K; Sjögren, Klara; Windahl, Sara H; Koskela, Antti; Grahnemo, Louise; Islander, Ulrika; Wilhelmson, Anna S; Tivesten, Åsa; Tuukkanen, Juha; Ohlsson, Claes

    2016-02-01

    Testosterone is a crucial regulator of the skeleton, but the role of the androgen receptor (AR) for the maintenance of the adult male skeleton is unclear. In the present study, the role of the AR for bone metabolism and skeletal growth after sexual maturation was evaluated by means of the drug enzalutamide, which is a new AR antagonist used in the treatment of prostate cancer patients. Nine-week-old male mice were treated with 10, 30, or 100 mg/kg·d of enzalutamide for 21 days or were surgically castrated and were compared with vehicle-treated gonadal intact mice. Although orchidectomy reduced the cortical bone thickness and trabecular bone volume fraction in the appendicular skeleton, these parameters were unaffected by enzalutamide. In contrast, both enzalutamide and orchidectomy reduced the bone mass in the axial skeleton as demonstrated by a reduced lumbar spine areal bone mineral density (P < .001) and trabecular bone volume fraction in L5 vertebrae (P < .001) compared with vehicle-treated gonadal intact mice. A compression test of the L5 vertebrae revealed that the mechanical strength in the axial skeleton was significantly reduced by enzalutamide (maximal load at failure -15.3% ± 3.5%; P < .01). The effects of enzalutamide in the axial skeleton were associated with a high bone turnover. In conclusion, enzalutamide reduces the bone mass in the axial but not the appendicular skeleton in male mice after sexual maturation. We propose that the effect of testosterone on the axial skeleton in male mice is mainly mediated via the AR. PMID:26587782

  4. Impact of axial velocity and transmembrane pressure (TMP) on ARP filter performance

    International Nuclear Information System (INIS)

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. One potential method for increasing filter flux is to adjust the axial velocity and transmembrane pressure (TMP). SRR requested SRNL to conduct bench-scale filter tests to evaluate the effects of axial velocity and transmembrane pressure on crossflow filter flux. The objective of the testing was to determine whether increasing the axial velocity at the ARP could produce a significant increase in filter flux. The authors conducted the tests by preparing slurries containing 6.6 M sodium Salt Batch 6 supernate and 2.5 g MST/L, processing the slurry through a bench-scale crossflow filter unit at varying axial velocity and TMP, and measuring filter flux as a function of time.

  5. Impact of axial velocity and transmembrane pressure (TMP) on ARP filter performance

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-02-29

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. One potential method for increasing filter flux is to adjust the axial velocity and transmembrane pressure (TMP). SRR requested SRNL to conduct bench-scale filter tests to evaluate the effects of axial velocity and transmembrane pressure on crossflow filter flux. The objective of the testing was to determine whether increasing the axial velocity at the ARP could produce a significant increase in filter flux. The authors conducted the tests by preparing slurries containing 6.6 M sodium Salt Batch 6 supernate and 2.5 g MST/L, processing the slurry through a bench-scale crossflow filter unit at varying axial velocity and TMP, and measuring filter flux as a function of time.

  6. Axial flow positive displacement worm compressor

    Science.gov (United States)

    Murrow, Kurt David (Inventor); Giffin, Rollin George (Inventor); Fakunle, Oladapo (Inventor)

    2010-01-01

    An axial flow positive displacement compressor has an inlet axially spaced apart and upstream from an outlet. Inner and outer bodies have offset inner and outer axes extend from the inlet to the outlet through first and second sections of a compressor assembly in serial downstream flow relationship. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes respectively. The inner and outer helical blades extend radially outwardly and inwardly respectively. The helical blades have first and second twist slopes in the first and second sections respectively. The first twist slopes are less than the second twist slopes. An engine including the compressor has in downstream serial flow relationship from the compressor a combustor and a high pressure turbine drivingly connected to the compressor by a high pressure shaft.

  7. Proto-I axial-focusing experiments

    International Nuclear Information System (INIS)

    The time-integrated axial (z) focus of the 4.5-cm-radius Proto I (1.5 MV, 500 kA) radial proton diode is presently limited to approx. 3 mm FWHM. This result is obtained with current neutralized beam transport in a gas cell with 6 Torr argon. If the vertical local divergence were the same (10 or less) as the horizontal divergence, the local divergence alone would produce a 1.5 mm FWHM focus. The axial focal size is evidently limited by time-dependent effects. These are studied by observing the beam incident upon various targets with two time-resolved pinhole cameras. The first camera observes Rutherford-scattered protons from gold targets with an array of 11 siicon PIN detectors. The second camera observes K/sub α/-fluorescence from aluminum targets with 4 independently-gated microchannel plates imaging tubes

  8. Microwave axial dielectric properties of carbon fiber

    Science.gov (United States)

    Hong, Wen; Xiao, Peng; Luo, Heng; Li, Zhuan

    2015-10-01

    Randomly distributed carbon fibers (CFs) reinforced epoxy resin composites are prepared by the pouring method, the dielectric properties of CF composites with different fiber content and length have been performed in the frequency range from 8.2 to 12.4 GHz. The complex permittivity of the composite increases with the fiber length, which is attributed to the decrease of depolarization field, and increases with the volume fraction, which is attributed to the increase of polarization. A formula, based on the theory of Reynolds-Hugh, is proposed to calculate the effective permittivity of CF composites, and validated by the experiments. The proposed formula is further applied to derive the axial permittivity of CF and analyze the effect of fiber length on the axial permittivity.

  9. Direct optical nanoscopy with axially localized detection

    CERN Document Server

    Bourg, N; Dupuis, G; Barroca, T; Bon, P; Lécart, S; Fort, E; Lévêque-Fort, S

    2014-01-01

    Evanescent light excitation is widely used in super-resolution fluorescence microscopy to confine light and reduce background noise. Herein we propose a method of exploiting evanescent light in the context of emission. When a fluorophore is located in close proximity to a medium with a higher refractive index, its near-field component is converted into light that propagates beyond the critical angle. This so-called Supercritical Angle Fluorescence (SAF) can be captured using a hig-NA objective and used to determine the axial position of the fluorophore with nanometer precision. We introduce a new technique for 3D nanoscopy that combines direct STochastic Optical Reconstruction Microscopy (dSTORM) imaging with dedicated detection of SAF emission. We demonstrate that our approach of a Direct Optical Nanoscopy with Axially Localized Detection (DONALD) yields a typical isotropic 3D localization precision of 20 nm.

  10. Review of Axial Burnup Distribution Considerations for Burnup Credit Calculations

    International Nuclear Information System (INIS)

    This report attempts to summarize and consolidate the existing knowledge on axial burnup distribution issues that are important to burnup credit criticality safety calculations. Recently released Nuclear Regulatory Commission (NRC) staff guidance permits limited burnup credit, and thus, has prompted resolution of the axial burnup distribution issue. The reactivity difference between the neutron multiplication factor (keff) calculated with explicit representation of the axial burnup distribution and keff calculated assuming a uniform axial burnup is referred to as the ''end effect.'' This end effect is shown to be dependent on many factors, including the axial-burnup profile, total accumulated burnup, cooling time, initial enrichment, assembly design, and the isotopics considered (i.e., actinide-only or actinides plus fission products). Axial modeling studies, efforts related to the development of axial-profile databases, and the determination of bounding axial profiles are also discussed. Finally, areas that could benefit from further efforts are identified

  11. Review of Axial Burnup Distribution Considerations for Burnup Credit Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J.C.; DeHart, M.D.

    2000-03-01

    This report attempts to summarize and consolidate the existing knowledge on axial burnup distribution issues that are important to burnup credit criticality safety calculations. Recently released Nuclear Regulatory Commission (NRC) staff guidance permits limited burnup credit, and thus, has prompted resolution of the axial burnup distribution issue. The reactivity difference between the neutron multiplication factor (keff) calculated with explicit representation of the axial burnup distribution and keff calculated assuming a uniform axial burnup is referred to as the ``end effect.'' This end effect is shown to be dependent on many factors, including the axial-burnup profile, total accumulated burnup, cooling time, initial enrichment, assembly design, and the isotopics considered (i.e., actinide-only or actinides plus fission products). Axial modeling studies, efforts related to the development of axial-profile databases, and the determination of bounding axial profiles are also discussed. Finally, areas that could benefit from further efforts are identified.

  12. On the problem of axial anomaly in supersymmetric gauge theories

    International Nuclear Information System (INIS)

    The explicit relation is found between the axial current obeying the Adler-Bardeen theorem and the supersymmetric one belonging to a supermultiplet. It is shown that the axial and superconformal anomalies are consistent in all orders of perturbation theory

  13. Multimode interaction in axially excited cylindrical shells

    OpenAIRE

    Silva F. M. A.; Rodrigues L.; Gonçalves P. B.; Del Prado Z. J. G. N

    2014-01-01

    Cylindrical shells exhibit a dense frequency spectrum, especially near the lowest frequency range. In addition, due to the circumferential symmetry, frequencies occur in pairs. So, in the vicinity of the lowest natural frequencies, several equal or nearly equal frequencies may occur, leading to a complex dynamic behavior. So, the aim of the present work is to investigate the dynamic behavior and stability of cylindrical shells under axial forcing with multiple equal or nearly equal natural fr...

  14. Axial flux permanent magnet brushless machines

    CERN Document Server

    Gieras, Jacek F; Kamper, Maarten J

    2008-01-01

    Axial Flux Permanent Magnet (AFPM) brushless machines are modern electrical machines with a lot of advantages over their conventional counterparts. They are being increasingly used in consumer electronics, public life, instrumentation and automation system, clinical engineering, industrial electromechanical drives, automobile manufacturing industry, electric and hybrid electric vehicles, marine vessels and toys. They are also used in more electric aircrafts and many other applications on larger scale. New applications have also emerged in distributed generation systems (wind turbine generators

  15. Axial Flow Characteristics within a Screw Compressor

    OpenAIRE

    Nouri, J. M.; Guerrato, D.; Stosic, N.; Arcoumanis, C.

    2008-01-01

    Angle-resolved axial mean flow and turbulence characteristics were measured inside the working chamber of the male rotor of a screw compressor with high spatial and temporal resolution using laser Doppler velocimetry at two rotor speeds, 750 and 1000 rpm. Measurements were performed through a transparent window near the discharge port to allow the application of various laser techniques. The results showed that an angular resolution up to 2° could fully describe the flow variation inside the ...

  16. Axial force measurement for esophageal function testing

    OpenAIRE

    Gravesen, Flemming H; Funch-Jensen, Peter; Gregersen, Hans; Drewes, Asbjørn Mohr

    2009-01-01

    The esophagus serves to transport food and fluid from the pharynx to the stomach. Manometry has been the “golden standard” for the diagnosis of esophageal motility diseases for many decades. Hence, esophageal function is normally evaluated by means of manometry even though it reflects the squeeze force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure o...

  17. Axially evoked postural reflexes: influence of task

    OpenAIRE

    Govender, Sendhil; Dennis, Danielle L.; Colebatch, James G.

    2014-01-01

    Postural reflexes were recorded in healthy subjects (n = 17) using brief axial accelerations and tap stimuli applied at the vertebra prominens (C7) and manubrium sterni. Short latency (SL) responses were recorded from the soleus, hamstrings and tibialis anterior muscles and expressed as a percentage of the background EMG prior to stimulus onset. In the majority of postural conditions tested, subjects were recorded standing erect and leaning forward with their feet together. The SL response wa...

  18. Numerical simulation of an axial blood pump.

    Science.gov (United States)

    Chua, Leok Poh; Su, Boyang; Lim, Tau Meng; Zhou, Tongming

    2007-07-01

    The axial blood pump with a magnetically suspended impeller is superior to other artificial blood pumps because of its small size. In this article, the distributions of velocity, path line, pressure, and shear stress in the straightener, the rotor, and the diffuser of the axial blood pump, as well as the gap zone were obtained using the commercial software, Fluent (version 6.2). The main focus was on the flow field of the blood pump. The numerical results showed that the axial blood pump could produce 5.14 L/min of blood at 100 mm Hg through the outlet when rotating at 11,000 rpm. However, there was a leakage flow of 1.06 L/min in the gap between the rotor cylinder and the pump housing, and thus the overall flow rate the impeller could generate was 6.2 L/min. The numerical results showed that 75% of the scalar shear stresses (SSs) were less than 250 Pa, and 10% were higher than 500 Pa within the whole pump. The high SS region appeared around the blade tip where a large variation of velocity direction and magnitude was found, which might be due to the steep angle variation at the blade tip. Because the exposure time of the blood cell at the high SS region within the pump was relatively short, it might not cause serious damage to the blood cells, but the improvement of blade profile should be considered in the future design of the axial pump. PMID:17584481

  19. DYNAMIC RESPONSES OF VISCOELASTIC AXIALLY MOVING BELT

    Institute of Scientific and Technical Information of China (English)

    李映辉; 高庆; 蹇开林; 殷学纲

    2003-01-01

    Based on the Kelvin viscoelastic differential constitutive law and the motion equation of the axially moving belt, the nonlinear dynamic model of the viscoelastic axial moving belt was established. And then it was reduced to be a linear differential system which the analytical solutions with a constant transport velocity and with a harmonically varying transport velocity were obtained by applying Lie group transformations. According to the nonlinear dynamic model, the effects of material parameters and the steady-state velocity and the perturbed axial velocity of the belt on the dynamic responses of the belts were investigated by the research of digital simulation. The result shows: 1 ) The nonlinear vibration frequency of the belt will become small when the relocity of the belt increases. 2 ) Increasing the value of viscosity or decreasing the value of elasticity leads to a deceasing in vibration frequencies. 3 ) The most effects of the transverse amplitudes come from the frequency of the perturbed velocity when the belt moves with harmonic velocity.

  20. Tricky Treats

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Tricky Treats shows children the difference between healthy snacks and sweet treats.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  1. Resolution of axial anomaly problem in supersymmetric gauge theories

    International Nuclear Information System (INIS)

    The explicit form of transformation is found which converters the operators, involved in axial anomaly, from the renormalization scheme obeying the Adler-BaAdeen theorem to a supersymmetric one. It is shown that there is no contradiction between axial current and superconformal anomalies. In supersymmetric scheme the axial current and its anomaly belong to the corresponding supermultiplets

  2. A new strategy of axial power distribution control based on three axial offsets concept

    International Nuclear Information System (INIS)

    We have proposed a very simple control procedure for axial xenon oscillation control based on a characteristic trajectory. The trajectory is drawn by three offsets of power distributions, namely, AOp, AOi and AOx. They are defined as the offset of axial power distribution, the offset of the power distribution under which the current iodine distribution is obtained as the equilibrium and that for xenon distribution, respectively. When these offsets are plotted on X-Y plane for (AOp-AOx, AOi-AOx) the trajectory draws a quite characteristic ellipse (or an elliptic spiral). On the other hands, Constant Axial Offset Control (CAOC) procedure is adopted as axial power distribution control strategy during both base load and load following operations in domestic PWRs. In the previous paper, we have presented an innovative procedure of axial power distribution control during load following in PWRs based on this trajectory such that the AOp-AOx is to be controlled to zero when the value deviates the pre-determined limiting values. In this paper we propose a modified control strategy to get more stability of axial power distributions. In this strategy, we control the trajectory to be close to the major axis of the ellipse when the power distribution reaches the limiting values. In other words, the plot is not controlled only to reduce AOp-AOx but also AOi-AOx is taken into account at the same time. It is known that when the plot is controlled to the major axis, it means that the point gives the peak position of axial xenon oscillation. Therefore xenon oscillation will not increase its amplitude any more. Thus more stable axial power distribution control is attained. This kind of design concept is quite important especially for the future PWRs with elongated fuel length and longer core life. Because in a longer effective core and also the longer core life, it has been known that the stability of axial xenon oscillation becomes more unstable. In this paper, some simulation

  3. Segmental and global lordosis changes with two-level axial lumbar interbody fusion and posterior instrumentation

    OpenAIRE

    Melgar, Miguel A; Tobler, William D.; Ernst, Robert J; Raley, Thomas J; Anand, Neel; Miller, Larry E; Nasca, Richard J

    2014-01-01

    Background Loss of lumbar lordosis has been reported after lumbar interbody fusion surgery and may portend poor clinical and radiographic outcome. The objective of this research was to measure changes in segmental and global lumbar lordosis in patients treated with presacral axial L4-S1 interbody fusion and posterior instrumentation and to determine if these changes influenced patient outcomes. Methods We performed a retrospective, multi-center review of prospectively collected data in 58 con...

  4. Axial flow heat exchanger devices and methods for heat transfer using axial flow devices

    Science.gov (United States)

    Koplow, Jeffrey P.

    2016-02-16

    Systems and methods described herein are directed to rotary heat exchangers configured to transfer heat to a heat transfer medium flowing in substantially axial direction within the heat exchangers. Exemplary heat exchangers include a heat conducting structure which is configured to be in thermal contact with a thermal load or a thermal sink, and a heat transfer structure rotatably coupled to the heat conducting structure to form a gap region between the heat conducting structure and the heat transfer structure, the heat transfer structure being configured to rotate during operation of the device. In example devices heat may be transferred across the gap region from a heated axial flow of the heat transfer medium to a cool stationary heat conducting structure, or from a heated stationary conducting structure to a cool axial flow of the heat transfer medium.

  5. CFD Simulation of Casing Treatment of Axial Flow Compressors

    Science.gov (United States)

    DeWitt, Kenneth

    2005-01-01

    A computational study is carried out to understand the physical mechanism responsible for the improvement in stall margin of an axial flow rotor due to the circumferential casing grooves. It is shown that the computational tool used predicts an increase in operating range of the rotor when casing grooves are present. A budget of the axial momentum equation is carried out at the rotor casing in the tip gap in order to uncover the physical process behind this stall margin improvement. It is shown that for the smooth casing the net axial pressure force . However in the presence of casing grooves the net axial shear stress force acting at the casing is augmented by the axial force due to the radial transport of axial momentum, which occurs across the grooves and power stream interface. This additional force adds to the net axial viscous sheer force and thus leads to an increase in the stall margin of the rotor.

  6. Drop size selection in axially heated co-axial fiber capillary instability

    Science.gov (United States)

    Mowlavi, Saviz; Brun, Pierre-Thomas; Gallaire, Francois

    2015-11-01

    We analyze the sphere size selection mechanism in silicon-in-silica sphere formation through the application of an external axial thermal gradient to a co-axial silicon-in-silica fiber (Gumennik et al., Nature Com., 2013). We first apply a convective/absolute stability analysis to the in-fibre capillary instability governing the sphere formation and demonstrate that the resulting wavelength selection predicts a finite but still too large wavelength. A global stability analysis is then pursued, which accounts for the spatial inhomogeneity of the base flow. F.G. acknowledges funding from ERC SimCoMiCs 280117.

  7. Axial electron-channelling analysis of perovskite

    International Nuclear Information System (INIS)

    The orientation dependence of characteristic X-ray emission (the Borrmann effect) under near-zone-axis diffraction conditions has been used to identify the site preferences of strontium, zirconium and uranium impurities within a CaTiO3 (perovskite) host structure. As characteristic emission lines from these impurities occur at both higher and lower energies than the calcium or titanium K-shell excitations, effects of delocalization are clearly measureable, and are used as a tool in axial electron channeling or ALCHEMI analysis. It is found that strontium and uranium strongly partition into calcium sites, whereas zirconium occupies titanium sites. (author)

  8. Single Band Helical Antenna in Axial Mode

    Directory of Open Access Journals (Sweden)

    Parminder Singh

    2012-11-01

    Full Text Available Helical antennas have been widely used in a various useful applications, due to their low weight and low profile conformability, easy and cheap realization.Radiation properties of this antenna are examined both theoretically and experimentally. In this paper, an attempt has been made to investigate new helical antenna structure for Applications. CST MWS Software is used for the simulation and design calculations of the helical antennas. The axial ratio, return loss, VSWR, Directivity, gain, radiation pattern is evaluated. Using CST MWS simulation software proposed antenna is designed/simulated and optimized. The antenna exhibits a single band from 0 GHz to 3 GHz for GPS and several satellite applications

  9. Resonances in axially symmetric dielectric objects

    CERN Document Server

    Helsing, Johan

    2016-01-01

    A high-order convergent and robust numerical solver is constructed and used to find complex eigenwavenumbers and electromagnetic eigenfields of dielectric objects with axial symmetry. The solver is based on Fourier--Nystr\\"om discretization of M\\"uller's combined integral equations for the transmission problem and can be applied to demanding resonance problems at microwave, terahertz, and optical wavelengths. High achievable accuracy, even at very high wavenumbers, makes the solver ideal for benchmarking and for assessing the performance of general purpose commercial software.

  10. Cervical Spine Axial Rotation Goniometer Design

    Directory of Open Access Journals (Sweden)

    Emin Ulaş Erdem

    2012-06-01

    Full Text Available To evaluate the cervical spine rotation movement is quiet harder than other joints. Configuration and arrangement of current goniometers and devices is not always practic in clinics and some methods are quiet expensive. The cervical axial rotation goniometer designed by the authors is consists of five pieces (head apparatus, chair, goniometric platform, eye pads and camera. With this goniometer design a detailed evaluation of cervical spine range of motion can be obtained. Besides, measurement of "joint position sense" which is recently has rising interest in researches can be made practically with this goniometer.

  11. Thermophoretic motion of bodies with axial symmetry

    International Nuclear Information System (INIS)

    Thermophoresis of axially symmetric bodies is investigated to first order in the Knudsen number, K n. The study is made in the limit where the typical length of the immersed body is small compared with the mean free path. It is shown that in this case, in contrast to what is the case for spherical bodies, the arising thermal force on the body is not in general anti-parallel to the temperature gradient. It is also shown that the gas exerts a torque on the body, which in magnitude and direction depends on the body geometry. Equations of motion describing the body movement are derived. Stationary solutions are studied

  12. Axial vessel widening in arborescent monocots.

    Science.gov (United States)

    Petit, Giai; DeClerck, Fabrice A J; Carrer, Marco; Anfodillo, Tommaso

    2014-02-01

    Dicotyledons have evolved a strategy to compensate for the increase in hydraulic resistance to water transport with height growth by widening xylem conduits downwards. In monocots, the accumulation of hydraulic resistance with height should be similar, but the absence of secondary growth represents a strong limitation for the maintenance of xylem hydraulic efficiency during ontogeny. The hydraulic architecture of monocots has been studied but it is unclear how monocots arrange their axial vascular structure during ontogeny to compensate for increases in height. We measured the vessel lumina and estimated the hydraulic diameter (Dh) at different heights along the stem of two arborescent monocots, Bactris gasipaes (Kunth) and Guadua angustifolia (Kunth). For the former, we also estimated the variation in Dh along the leaf rachis. Hydraulic diameter increased basally from the stem apex to the base with a scaling exponent (b) in the range of those reported for dicot trees (b = 0.22 in B. gasipaes; b = 0.31 and 0.23 in G. angustifolia). In B. gasipaes, vessels decrease in Dh from the stem's centre towards the periphery, an opposite pattern compared with dicot trees. Along the leaf rachis, a pattern of increasing Dh basally was also found (b = 0.13). The hydraulic design of the monocots studied revealed an axial pattern of xylem conduits similar to those evolved by dicots to compensate and minimize the negative effect of root-to-leaf length on hydrodynamic resistance to water flow. PMID:24488857

  13. The failure of axially loaded steel columns

    International Nuclear Information System (INIS)

    Slender compression steel members fail by elastic bucking, and short compression members may be loaded until the steel yields. In the majority of usual situations, failure occurs by inelastic buckling after a portion of the cross section has yielded. Residual stresses are the primary cause of the nonlinear protion of the average stress strain curve of axially loaded compression members (huber and Beedle, 1954). A number of theories tackled the problem of inelastic bucking. The LRFD Code ended with adopting an empirical parabolic equation that is stitched to the Euler hyperbola at the column slenderness value of λ C =2 square root and is believed to provide a reasonable approximation for column strength curves. The analysis of steel sections used in this paper defines an explicit from of failure to define the failure load of axially loaded columns in the inelastic range. inelastic bucking is defined in terms of the elaSTIC bucking of transformed sections. Two examples are used to clarify the method of analysis that accounts for residual stresses. (author). 9 refs., 5 figs

  14. Atroposelective Synthesis of Axially Chiral Thiohydantoin Derivatives.

    Science.gov (United States)

    Sarigul, Sevgi; Dogan, Ilknur

    2016-07-15

    Nonracemic axially chiral thiohydantoins were synthesized atroposelectively by the reaction of o-aryl isothiocyanates with amino acid ester salts in the presence of triethylamine (TEA). The synthesis of the nonaxially chiral derivatives, however, gave thiohydantoins racemized at C-5 of the heterocyclic ring. The micropreparatively resolved enantiomers of the nonaxially chiral derivatives from the racemic products were found to be optically stable under neutral conditions. On formation of the 5-methyl-3-arylthiohydantoin ring, bulky o-aryl substituents at N3 were found to suppress the C-5 racemization and in this way enabled the transfer of chirality from the α-amino acid to the products. The corresponding 5-isopropylthiohydantoins turned out to be more prone to racemization at C-5 during the ring formation. The isomer compositions of the synthesized axially chiral thiohydantoins have been determined through HPLC analyses with chiral stationary phases. In most cases a high prevalence of the P isomers over the M isomers has been obtained. The barriers to rotation determined around the Nsp(2)-Caryl chiral axis were found to be dependent upon the size of the o-halo aryl substituents. PMID:27322739

  15. Proton spin and baryon octet axial couplings

    International Nuclear Information System (INIS)

    Peripheral spin structure of the nucelon generated by the soft mesonic radiative corrections is studied within the light-cone perturbation theory. Starting with the tree-level SU(6) symmetry, we find a good description of the axial-vector couplings in β-decay of hyperons. We study the proton helicity flow from the baryonic core to the angular momentum of the pionic cloud. It is found that in the relativistic light-cone approach the spin-flip pattern is different from that in the coventional non-relativistic models. The axial-vector current matrix elements are shown to receive large corrections from beyond the conventional static limit. The important virtue of using the light-cone vertex functions of the meson-baryon Fock components of the proton is that the local gauge invariance and the energy-momentum sum rule are satisfied automatically. We infer the radius of the light-cone form factor from an analysis of the experimental data on the fragmentation of high-energy protons into nucleons and hyperons-the process dominated by stripping off the mesons of the meson-baryon Fock states. (orig.)

  16. NUMERICAL INVESTIGATION OF PERFORMANCE OF AN AXIAL-FLOW PUMP WITH INDUCER

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The interaction of flow through the inducer and impeller of an axial-flow pump equipped with an inducer has significant effect on its performance. This article presents a recent numerical investigation on this topic. The studied pump has an inducer with 3 blades mounted on a conical hub and a 6-blade impeller. The blade angle of the impeller is adjustable to generate different relative circumferential angles between the inducer blade trailing edge and the impeller blade leading edge. A computational fluid dynamics code was used to investigate the flow characteristics and performance of the axial-flow pump. For turbulence closure, the RNG k-ε model was applied with an unstructured grid system. The rotor-stator interaction was treated with a Multiple Reference Frame (MRF) strategy. Computations were performed in different cases: 7 different relative circumferential angles (△θ) between the inducer blade trailing edge and the impeller blade leading edge, and 3 different axial gaps (G) between the inducer and the impeller. The variation of the hydraulic loss in the rotator was obtained by changing △θ. The numerical results show that the pressure generated is minimum in the case of (G=%3D), which indicates that the interference between inducer and impeller is strong if the axial gap is small. The pump performances were predicted and compared to the experimental measurements. Recommendations for future modifications and improvements to the pump design were also given.

  17. Chiral dynamics and heavy-fermion formalism in nuclei; 1, exchange axial currents

    CERN Document Server

    Park, T S; Rho, M; Park, Tae-Sun; Min, Dong-Pil; Rho, Mannque

    1993-01-01

    Chiral perturbation theory in heavy-fermion formalism is developed for meson-exchange currents in nuclei and applied to nuclear axial- charge transitions. Calculation is performed to the next-to-leading order in chiral expansion which involves graphs up to one loop. The result turns out to be very simple. The previously conjectured notion of "chiral filter mechanism" in the time component of the nuclear axial current and the space component of the nuclear electromagnetic current is verified to that order. As a consequence, the phenomenologically observed soft-pion dominance in the nuclear process is given a simple interpretation in terms of chiral symmetry in nuclei. In this paper, we focus on the axial current, relegating the EM current which can be treated in a similar way to a separate paper. We discuss the implication of our result on the enhanced axial-charge transitions observed in heavy nuclei and clarify the relationship between the phenomenological meson-exchange description and the chiral Lagrangian...

  18. Investigation of multipactor breakdown in communication satellite microwave co-axial systems

    Indian Academy of Sciences (India)

    S K Nagesh; D Revannasiddiah; S V K Shastry

    2005-01-01

    Multipactor breakdown or multipactor discharge is a form of high frequency discharge that may occur in microwave components operating at very low pressures. Some RF components of multi-channel communication satellites have co-axial geometry and handle high RF power under near-vacuum conditions. The breakdown occurs due to secondary electron resonance, wherein electrons move back and forth in synchronism with the RF voltage across the gap between the inner and outer conductors of the co-axial structure. If the yield of secondary electrons from the walls of the co-axial structure is greater than unity, then the electron density increases with time and eventually leads to the breakdown. In this paper, the current due to the oscillating electrons in the co-axial geometry has been treated as a radially oriented Hertzian dipole. The electric field, due to this dipole, at any point in the coaxial structure, may then be determined by employing the dyadic Green’s function technique. This field has been compared with the field that would exist in the absence of multipactor.

  19. Axial stress corrosion cracking forming method to metal tube

    International Nuclear Information System (INIS)

    Generally, it is more difficult in a metal tube, to intentionally cause a stress corrosion cracking in axial direction than in circumferential direction. In the present invention, a bevel is formed on a metal tube and welding is conducted in circumferential direction along the bevel, and welding is conducted in axial direction partially to the portion welded in circumferential direction. Namely, a bevel is formed in circumferential direction to an abutting portion of thick-walled metal tubes with each other, welding is conducted in circumferential direction along the bevel, and welding is conducted in axial direction partially to a portion welded in circumferential direction. With such procedures, since tensile stress in the circumferential direction is increased partially at a portion welded in axial direction, stress corrosion cracking is caused in axial direction at the portion. Then, stress corrosion cracking in axial direction can thus be formed on the thick-walled metal tube. (N.H.)

  20. Universal Axial Algebras and a Theorem of Sakuma

    OpenAIRE

    Hall, J I; Rehren, F; Shpectorov, S.

    2013-01-01

    In the first half of this paper, we define axial algebras: nonassociative commutative algebras generated by axes, that is, semisimple idempotents---the prototypical example of which is Griess' algebra [C85] for the Monster group. When multiplication of eigenspaces of axes is controlled by fusion rules, the structure of the axial algebra is determined to a large degree. We give a construction of the universal Frobenius axial algebra on $n$ generators with a specified fusion rules, of which all...

  1. Composite Axial Flow Propulsor for Small Aircraft

    Directory of Open Access Journals (Sweden)

    R. Poul

    2005-01-01

    Full Text Available This work focuses on the design of an axial flow ducted fan driven by a reciprocating engine. The solution minimizes the turbulization of the flow around the aircraft. The fan has a rotor - stator configuration. Due to the need for low weight of the fan, a carbon/epoxy composite material was chosen for the blades and the driving shaft.The fan is designed for optimal isentropic efficiency and free vortex flow. A stress analysis of the rotor blade was performed using the Finite Element  Method. The skin of the blade is calculated as a laminate and the foam core as a solid. A static and dynamic analysis were made. The RTM technology is compared with other technologies and is described in detail. 

  2. Axially symmetric static sources of gravitational field

    CERN Document Server

    Hernandez-Pastora, J L; Martin, J

    2016-01-01

    A general procedure to find static and axially symmetric, interior solutions to the Einstein equations is presented. All the so obtained solutions, verify the energy conditions for a wide range of values of the parameters, and match smoothly to some exterior solution of the Weyl family, thereby representing globally regular models describing non spherical sources of gravitational field. In the spherically symmetric limit, all our models converge to the well known incompressible perfect fluid solution.The key stone of our approach is based on an ansatz allowing to define the interior metric in terms of the exterior metric functions evaluated at the boundary source. Some particular sources are obtained, and the physical variables of the energy-momentum tensor are calculated explicitly, as well as the geometry of the source in terms of the relativistic multipole moments. The total mass of different configurations is also calculated, it is shown to be equal to the monopole of the exterior solution.

  3. Fragmentation of an axially impacted slender rod

    Science.gov (United States)

    Ji, W.; Waas, A. M.

    2010-02-01

    Motivated by experimental results on the dynamic buckling and fragmentation of a vertical column impacted by a falling mass, results from an analytical model for dynamic buckling which considers the dynamic interaction between the axial column deformation and the out-of-plane buckling displacements are used to interpret the fragmentation process and the resulting fragment lengths. It is shown that a critical time exists for the rod to undergo fragmentation. At this critical time, the rod deforms in a modulated pattern of waves, setting up the stage for the ensuing fragmentation as a result of induced large curvatures that exceed the critical bending strain of the rod material. The resulting fragment length distributions, which show two characteristics peaks at \\frac{\\lambda}{2} and \\frac{\\lambda}{4} , where λ is a characteristic half-wavelength, are found to compare favorably with the experimental results.

  4. Acoustic horizons in axially symmetric relativistic accretion

    CERN Document Server

    Abraham, H; Das, T K; Abraham, Hrvoje; Bilic, Neven; Das, Tapas K.

    2006-01-01

    Transonic accretion onto astrophysical objects is a unique example of analogue black hole realized in nature. In the framework of acoustic geometry we study axially symmetric accretion and wind of a rotating astrophysical black hole or of a neutron star assuming isentropic flow of a fluid described by a polytropic equation of state. In particular we analyze the causal structure of multitransonic configurations with two sonic points and a shock. Retarded and advanced null curves clearly demonstrate the presence of the acoustic black hole at regular sonic points and of the white hole at the shock. We calculate the analogue surface gravity and the Hawking temperature for the inner and the outer acoustic horizons.

  5. Dynamics of Flapping Flag in Axial Flow

    Science.gov (United States)

    Abderrahmane, Hamid Ait; Fayed, Mohamed; Gunter, Amy-Lee; Paidoussis, Michael P.; Ng, Hoi Dick

    2010-11-01

    We investigate experimentally the phenomenon of the flapping of a flag, placed within a low turbulent axial flow inside a small scale wind tunnel test section. Flags of different sizes and flexural rigidities were used. Image processing technique was used and the time series of a given point on the edge of the flag was analyzed. The stability condition of the flag was obtained and compared to the recent theoretical models and numerical simulations. Afterwards, the nonlinear dynamics of the flapping was investigated using nonlinear time series method. The nonlinear dynamics is depicted in phase space and the correlation dimension of the attractors is determined. On the basis of observations made in this study, some conclusions on the existing models were drawn.

  6. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    The objects of this invention are first to reduce the time required to obtain statistically significant data in trans-axial tomographic radioisotope scanning using a scintillation camera. Secondly, to provide a scintillation camera system to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a known radiation source without sacrificing spatial resolution. Thirdly to reduce the scanning time without loss of image clarity. The system described comprises a scintillation camera detector, means for moving this in orbit about a cranial-caudal axis relative to a patient and a collimator having septa defining apertures such that gamma rays perpendicular to the axis are admitted with high spatial resolution, parallel to the axis with low resolution. The septa may be made of strips of lead. Detailed descriptions are given. (U.K.)

  7. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    The principal problem in trans-axial tomographic radioisotope scanning is the length of time required to obtain meaningful data. Patient movement and radioisotope migration during the scanning period can cause distortion of the image. The object of this invention is to reduce the scanning time without degrading the images obtained. A system is described in which a scintillation camera detector is moved to an orbit about the cranial-caudal axis relative to the patient. A collimator is used in which lead septa are arranged so as to admit gamma rays travelling perpendicular to this axis with high spatial resolution and those travelling in the direction of the axis with low spatial resolution, thus increasing the rate of acceptance of radioactive events to contribute to the positional information obtainable without sacrificing spatial resolution. (author)

  8. Axially symmetric Lorentzian wormholes in general relativity

    International Nuclear Information System (INIS)

    The field equations of Einstein's theory of general relativity, being local, do not fix the global structure of space-time. They admit topologically non-trivial solutions, including spatially closed universes and the amazing possibility of shortcuts for travel between distant regions in space and time - so-called Lorentzian wormholes. The aim of this thesis is to (mathematically) construct space-times which contain traversal wormholes connecting arbitrary distant regions of an asymptotically flat or asymptotically de Sitter universe. Since the wormhole mouths appear as two separate masses in the exterior space, space-time can at best be axially symmetric. We eliminate the non-staticity caused by the gravitational attraction of the mouths by anchoring them by strings held at infinity or, alternatively, by electric repulsion. The space-times are obtained by surgically grafting together well-known solutions of Einstein's equations along timelike hypersurfaces. This surgery naturally concentrates a non-zero stress-energy tensor on the boundary between the two space-times which can be investigated by using the standard thin shell formalism. It turns out that, when using charged black holes, the provided constructions are possible without violation of any of the energy conditions. In general, observers living in the axially symmetric, asymptotically flat (respectively asymptotically de Sitter) region axe able to send causal signals through the topologically non-trivial region. However, the wormhole space-times contain closed timelike curves. Because of this explicit violation of global hyperbolicity these models do not serve as counterexamples to known topological censorship theorems. (author)

  9. Transverse vibration characteristics of axially moving viscoelastic plate

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yin-feng; WANG Zhong-min

    2007-01-01

    The dynamic characteristics and stability of axially moving viscoelastic rectangular thin plate are investigated. Based on the two dimensional viscoelastic differential constitutive relation, the differential equations of motion of the axially moving viscoelastic plate are established. Dimensionless complex frequencies of an axially moving viscoelastic plate with four edges simply supported, two opposite edges simply supported and other two edges clamped are calculated by the differential quadrature method. The effects of the aspect ratio, moving speed and dimensionless delay time of the material on the transverse vibration and stability of the axially moving viscoelastic plate are analyzed.

  10. Green's Functions in Axial and Lorentz-type Gauges and Application to The Axial Pole Prescription and The Wilson Loop

    OpenAIRE

    Joglekar, Satish D.

    2000-01-01

    We summarize the work done in connecting Green's functions in a different classes of gauges and its applications to the problems in the axial gauges.The procedure adopted uses finite field-dependent BRS [FFBRS] transformations to connect axial and the Lorentz type gauges.These transformations preserve the vacuum expectation of gauge-invariant observables explicitly. We discuss the applications of these ideas to the axial gauge pole problem and to the preservation of the Wilson loop and the th...

  11. Test Setup for Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina

    The test setup for testing axially static and cyclic loaded piles in sand is described in the following. The purpose for the tests is to examine the tensile capacity of axially loaded piles in dense fully saturated sand. The pile dimensions are chosen to resemble full scale dimension of piles used...

  12. An Unbroken Axial-Vector Current Conservation Law

    Science.gov (United States)

    Sharafiddinov, Rasulkhozha S.

    2016-04-01

    The mass, energy and momentum of the neutrino of a true flavor have an axial-vector nature. As a consequence, the left-handed truly neutral neutrino in an axial-vector field of emission can be converted into a right-handed one and vice versa. This predicts the unidenticality of masses, energies and momenta of neutrinos of the different components. Recognizing such a difference in masses, energies, momenta and accepting that the left-handed axial-vector neutrino and the right-handed antineutrino of true neutrality refer to long-lived C-odd leptons, and the right-handed truly neutral neutrino and the left-handed axial-vector antineutrino are of short-lived fermions of C-oddity, we would write a new CP-even Dirac equation taking into account the flavor symmetrical axial-vector mass, energy and momentum matrices. Their presence explains the spontaneous mirror symmetry violation, confirming that an axial-vector current conservation law has never violated. They reflect the availability of a mirror Minkowski space in which a neutrino is characterized by left as well as by right space-time coordinates. Therefore, it is not surprising that whatever the main purposes experiments about a quasielastic axial-vector mass say in favor of an axial-vector mirror Minkowski space-time.

  13. Improved axial flux shape generator for quick DNB test

    International Nuclear Information System (INIS)

    Axial power shapes that develop during power maneuvering in pressurized water reactors must be analyzed to ensure that adequate margin to avoid departure from nucleate boiling (DNB) is maintained during these transients. In order to reduce the number of flux shapes that need to be analyzed in detail to determine DNB ratio (DNBR), often generic axial flux shapes are analyzed and Maximum Allowable Peaking (MAP) limits are determined to conservatively filter those actual axial power shapes that are clearly safe. Current generic MAP limits, obtained for axial flux shapes, generated by a two-parameter based axial flux shape generator, are overly conservative for some power shapes and nonconservative for others leading to unnecessary operational restrictions on conservative cases. A penalty is imposed on nonconservative cases. In order to reduce the number of overly conservative and nonconservative cases, the authors have developed a new generic axial power shape generator, that is based on three parameters. Generic MAP limits have been developed for the new axial flux shape generator and tested using real flux shapes by plotting the percent deviation of MAP limits for generic flux shapes from the corresponding value for actual flux shapes. New axial flux shape generator, which is clearly superior as it leads to significantly lower percent deviation, will lead to reduced man-hours for detailed DNBR analyses and remove some of the unnecessary operational restrictions imposed by the old flux shape generator

  14. A new approach to radial and axial gauges

    Energy Technology Data Exchange (ETDEWEB)

    Weigert, H.; Heinz, U. (Regensburg Univ. (Germany). Inst. fuer Theoretische Physik)

    1992-10-01

    We develop a new path integral formulation of QCD in radial and axial gauges. This formalism yields free propagators which are free of gauge poles. We find that radial gauges are ghost free. In axial gauges ghosts cannot generally be excluded from the formalism due to the need to fix the residual gauge freedom. (orig.).

  15. Study of a new airfoil used in reversible axial fans

    Science.gov (United States)

    Li, Chaojun; Wei, Baosuo; Gu, Chuangang

    1991-01-01

    The characteristics of the reverse ventilation of axial flow are analyzed. An s shaped airfoil with a double circular arc was tested in a wind tunnel. The experimental results showed that the characteristics of this new airfoil in reverse ventilation are the same as those in normal ventilation, and that this airfoil is better than the existing airfoils used on reversible axial fans.

  16. Multimode interaction in axially excited cylindrical shells

    Directory of Open Access Journals (Sweden)

    Silva F. M. A.

    2014-01-01

    Full Text Available Cylindrical shells exhibit a dense frequency spectrum, especially near the lowest frequency range. In addition, due to the circumferential symmetry, frequencies occur in pairs. So, in the vicinity of the lowest natural frequencies, several equal or nearly equal frequencies may occur, leading to a complex dynamic behavior. So, the aim of the present work is to investigate the dynamic behavior and stability of cylindrical shells under axial forcing with multiple equal or nearly equal natural frequencies. The shell is modelled using the Donnell nonlinear shallow shell theory and the discretized equations of motion are obtained by applying the Galerkin method. For this, a modal solution that takes into account the modal interaction among the relevant modes and the influence of their companion modes (modes with rotational symmetry, which satisfies the boundary and continuity conditions of the shell, is derived. Special attention is given to the 1:1:1:1 internal resonance (four interacting modes. Solving numerically the governing equations of motion and using several tools of nonlinear dynamics, a detailed parametric analysis is conducted to clarify the influence of the internal resonances on the bifurcations, stability boundaries, nonlinear vibration modes and basins of attraction of the structure.

  17. Analysis of SONACO axial cooling experiments

    International Nuclear Information System (INIS)

    The SONACO test rig contained a sodium-cooled, electrically heated 37-pin bundle. On this rig, a series of forced, mixed and natural convection experiments have been performed with the aim of contributing to the understanding of thermal-hydraulic phenomena and providing data for code validation for a subassembly at decay heat power level with low flow or stagnant coolant. The test section and especially the heater pins were equipped with an extensive number of chromel-alumel thermocouples. In addition, special permanent-magnet probes were used for measuring local velocities. In this paper we give a survey of results from axial cooling experiments, where heat was removed by natural convection to a cooling coil situated in the coolant channel (plenum) above the bundle. The experimental conditions led to turbulent convection with a slowly varying, large scale flow pattern. It is shown that a power tilt in the bundle reduces these fluctuations but does not eliminate them. For the uniformly heated bundle, aglebraic expressions for the average turbulent heat flux as well as for temperature and velocity fluctuations are derived from a second-moments model and compared with experimental data. Furthermore, heat transfer in the plenum and the consequences of the SONACO experiments for the coolability of reactor fuel elements under loss-of-flow conditions are discussed. ((orig.))

  18. Axial change in semi-leptonic processes

    International Nuclear Information System (INIS)

    According to a general argument the time component AOof the axial current should have a large exchange current Aexch0due to a soft-pion exchange diagram the structure and magnitude of which are dictated by current algebra and the low-energy theorem. This implies that Aexch0carries valuable information on the role of chiral symmetry in nuclear medium, and many theoretical and experimental studies have been devoted to Aexch0 in the recent years. My talk surveys the latest developments in these studies. I first review the current status2 of analysis of the relevant Β decay data, paying particular attention to the assessment of nuclear physics uncertainties. I then discuss the observed extra enhancement of Aexch0 over the soft-pion prediction. Two possible explanations to this problem have been reported in the literature: (1) contributions of heavy- meson exchange processes; (2) higher-order terms in chiral perturbation expansion. I review critically these two different approaches and discuss a possible interrelation between them. Finally, I touch upon the relevance of Aexch0 to the in-medium value of the pseudoscalar form factor gp

  19. Axially Loaded Behavior of Driven PC Piles

    Science.gov (United States)

    Hsu, Shih-Tsung

    2010-05-01

    To obtain a fair load-settlement curve of a driven pile, and to evaluate the ultimate pile capacity more accurately, a numerical model was created to simulate the ground movements during a pile being driven. After the procedure, the axially loaded behaviors of the piles in silty sand were analyzed. The numerical results are compared with those results by full scale pile load tests. It was found, although the loads added on the tested piles are different from those by the numerical analyses which applied displacement increments on piles, the load-settlement behaviors of piles calculated from the numerical model were close to those measured from field tests before the piles stressed to peak. Total load, shaft friction, and point bearing do not reach peak values at the same pile settlement; furthermore, the point bearing slowly increases all the while, with no peak. However, the point bearing only contributes 10˜20% of ultimate pile capacity. No matter which relative density of silty sand, pile diameter, and pile length increased, ultimate pile capacity increased as well.

  20. The Klinger hot gas double axial valve

    International Nuclear Information System (INIS)

    The Klinger hot gas valve is a medium controlled double axial valve with advanced design features and safety function. It was first proposed by Klinger early in 1976 for the PNP-Project as a containment shut-off for hot helium (918 deg. C and 42 bar), because a market research has shown that such a valve is not state of present techniques. In the first stage of development a feasibility study had to be made by detailed design, calculation and by basic experiments for key components in close collaboration with Interatom/GHT. This was the basis for further design, calculation, construction and experimental work for such a valve prototype within the new development contract. The stage of knowledge to that time revealed the following key priority development areas: Finite element stress analysis for the highly stressed high temperature main components; development of an insulation layout; Detailed experimental tests of functionally important structural components or units of the valve, partly at Klingers (gasstatic bearings, flexible metallic sealing element, aerodynamic and thermohydraulic tests), partly at Interatom (actuator unit and also gasstatic bearings), partly at HRB in Juelich (flexible metallic sealing system, aerodynamic and thermohydraulic tests); Design of a test valve for experimental work in the KVK (test circuit at Interatom) for evaluation of temperature distribution and reliability of operation; Design of a prototype and extensive testing in the KVK

  1. Axial channeling of boron ions into silicon

    Science.gov (United States)

    La Ferla, A.; Galvagno, G.; Raineri, V.; Setola, R.; Rimini, E.; Carbera, A.; Gasparotto, A.

    1992-04-01

    Channeling boron implants were performed into (100) and (110) silicon substrates in the energy range 80-700 keV. The dose ranged between 3.5 × 10 11 and 1 × 10 15 atoms/cm 2. The axial channeling concentration profiles of implanted B + were compared with that obtained for incidence along the random direction of the crystal and with that obtained by implantation in amorphous silicon. The electrical and chemical boron distributions were obtained by spreading resistance and secondary ion mass spectrometry measurements, respectively. The inelastic stopping power, Sc, was extracted from the experimental maximum ranges for the [100] and [110] axis. The energ dependence of the electronic stopping power is given by Sc = KEp with p[100] = 0.469±0.010 and p[110] = 0.554±0.004. Simulations obtained by the MARLOWE code, using the Oen-Robinson impact parameter dependent formula, for the electronic energy loss reproduce quite well the experimental depth profiles.

  2. Axial channeling of boron ions into silicon

    International Nuclear Information System (INIS)

    Channeling boron implants were performed into (100) and (110) silicon substrates in the energy range 80-700 keV. The dose ranged between 3.5x1011 and 1x1015 atoms/cm2. The axial channeling concentration profiles of implanted B+ were compared with that obtained for incidence along the random direction of the crystal and with that obtained by implantation in amorphous silicon. The electrical and chemical boron distributions were obtained by spreading resistance and secondary ion mass spectrometry measurements, respectively. The inelastic stopping power, Sc, was extracted from the experimental maximum ranges for the [100] and [110] axis. The energy dependence of the electronic stopping power is given by Se = KEp with p[100] = 0.469±0.010 and p[110] = 0.554±0.004. Simulations obtained by the MARLOWE code, using the Oen-Robinson impact parameter dependent formula, for the electronic energy loss reproduce quite well the experimental depth profiles. (orig.)

  3. Axial channeling of boron ions into silicon

    Energy Technology Data Exchange (ETDEWEB)

    La Ferla, A.; Galvagno, G. (Ist. di Tecnologie e Metodologie per la Microelettronica, CNR, Dipt. di Fisica, Catania (Italy)); Raineri, V.; Setola, R.; Rimini, E. (Dipt. di Fisica, Univ. di Catania (Italy)); Carnera, A.; Gasparotto, A. (Dipt. di Fisica, Univ. di Padova (Italy))

    1992-04-01

    Channeling boron implants were performed into (100) and (110) silicon substrates in the energy range 80-700 keV. The dose ranged between 3.5x10{sup 11} and 1x10{sup 15} atoms/cm{sup 2}. The axial channeling concentration profiles of implanted B{sup +} were compared with that obtained for incidence along the random direction of the crystal and with that obtained by implantation in amorphous silicon. The electrical and chemical boron distributions were obtained by spreading resistance and secondary ion mass spectrometry measurements, respectively. The inelastic stopping power, S{sub c}, was extracted from the experimental maximum ranges for the (100) and (110) axis. The energy dependence of the electronic stopping power is given by S{sub e} = KE{sup p} with p{sub (100)} = 0.469{+-}0.010 and p{sub (110)} = 0.554{+-}0.004. Simulations obtained by the MARLOWE code, using the Oen-Robinson impact parameter dependent formula, for the electronic energy loss reproduce quite well the experimental depth profiles. (orig.).

  4. Análisis de la fuerza axial en un transportador de sinfín // Analysis of axial force in a screw conveyor.

    Directory of Open Access Journals (Sweden)

    F. Aguilar Parés

    1999-01-01

    Full Text Available Durante el movimiento de un material en un transportador de sinfín surge una fuerza en dirección axial que influye en laselección de uno de los cojinetes de apoyo del equipo. En el artículo aparecen algunas soluciones constructivas que tienen encuentan la fuerza axial. Por otro lado se establece la relación entre la fuerza axial y el empuje axial y se precisa de quiendepende el sentido del empuje axial. Por último se propone un modelo matemático que relaciona la fuerza axial con la potenciarequerida por el equipo.Palabras claves: Transportador de sinf in, fuerza axial , empuje axial ._________________________________________________________________________AbstractDuring the movement of material in a screw conveyor surge a force in axial direction that influence in the selection of one ofthe equipment support bearings. Some constructive solutions appear in the article for considering the axial force. In the otherhand it is established the relation between axial force and axial thurst and it is precised whose direction thurst axial depend of.Finally it is proposed a mathematic model that relates the axial force with the power required by the equipment.Key words: Screw conveyor, axial force, axial thurst .

  5. Reactivity effects of nonuniform axial burnup distributions on spent fuel

    International Nuclear Information System (INIS)

    When conducting future criticality safety analyses on spent fuel shipping casks, burnup credit may play a significant role in determining the number of fuel assemblies that can be safely loaded into each cask. An important area in burnup credit analysis is the burnup variation along the length of the fuel assembly, which is determined by the location of the assembly in the reactor core and its residence time. A study of the effects of axial burnup distributions on reactivity has been conducted, using data from existing power plant fuel. Utilizing a one-dimensional, two-group diffusion code, named REALAX, the reactivity effects of axial burnup profiles have been calculated for various PWR fuel assemblies. The reactivity effects calculated by the code are defined in terms of k for the axially dependent burnup distribution minus k for a uniform axial burnup distribution at the assembly average burnup divided by k for a uniform axial burnup distribution at the assembly average burnup. Criticality safety specialists can take advantage of the quick-running code to determine axial effects of different assembly burnup profiles. In general, the positive reactivity effects of axial burnup distributions increase as burnup increases, though they do not increase faster than the overall decrease in reactivity due to burnup

  6. Reactivity effects of nonuniform axial burnup distributions on spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Leary, R.W. II; Parish, T.A. [Texas A & M Univ., College Station, TX (United States)

    1995-12-01

    When conducting future criticality safety analyses on spent fuel shipping casks, burnup credit may play a significant role in determining the number of fuel assemblies that can be safely loaded into each cask. An important area in burnup credit analysis is the burnup variation along the length of the fuel assembly, which is determined by the location of the assembly in the reactor core and its residence time. A study of the effects of axial burnup distributions on reactivity has been conducted, using data from existing power plant fuel. Utilizing a one-dimensional, two-group diffusion code, named REALAX, the reactivity effects of axial burnup profiles have been calculated for various PWR fuel assemblies. The reactivity effects calculated by the code are defined in terms of k for the axially dependent burnup distribution minus k for a uniform axial burnup distribution at the assembly average burnup divided by k for a uniform axial burnup distribution at the assembly average burnup. Criticality safety specialists can take advantage of the quick-running code to determine axial effects of different assembly burnup profiles. In general, the positive reactivity effects of axial burnup distributions increase as burnup increases, though they do not increase faster than the overall decrease in reactivity due to burnup.

  7. Pion as a Longitudinal Axial-Vector Meson $q\\bar{q}$ Bound State

    CERN Document Server

    Pham, T N

    2013-01-01

    The success of the Adler-Bell-Jackiw(ABJ) chiral anomaly prediction for $\\pi^{0}\\to \\gamma\\gamma$ decay rate shows that non-anomaly terms would make a negligible contribution to the decay rate, in agreement with the Sutherland-Veltman theorem. Thus the conventional $q\\bar{q}$ bound-state description of the pion could not be valid since it would produce a $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude not suppressed in the soft pion limit, in contradiction with the Sutherland-Veltman theorem. Therefore, if the pion is to be treated as a $q\\bar{q}$ bound state, this bound state would be a longitudinal axial-vector meson. In this paper, we consider the pion to be a longitudinal axial-vector meson $q\\bar{q}$ state with derivative coupling for the pion-$q\\bar{q}$ Bethe-Salpeter(BS) amplitude. We shall show that, the longitudinal axial-vector meson solution for the pion $q\\bar{q}$ Bethe-Salpeter wave function could produce a suppressed $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude in the soft pion limit, in agreement with t...

  8. Gravitational waves from the axial perturbations of hyperon stars

    Institute of Scientific and Technical Information of China (English)

    Wen De-Hua; Yan Jing; Liu Xue-Mei

    2012-01-01

    The eigen-frequencies of the axial w-mode oscillations of hyperon stars are examined.It is shown that as the appearance of hyperons softens the equation of state of the super-density matter,the frequency of gravitational waves from the axial w-mode of hyperon star becomes smaller than that of a traditional neutron star at the same stellar mass.Moreover,the eigenfrequencies of hyperon stars also have scaling universality.It is shown that the EURO thirdgeneration gravitational-wave detector has the potential to detect the gravitational-wave signal emitted from the axial w-mode oscillations of a hyperon star.

  9. Tensile Property of Bi-axial Warp Knitted Structure

    Institute of Scientific and Technical Information of China (English)

    沈为

    2003-01-01

    The tensile property of bi-axial warp knitted fabrics is tested and compared with that of the plain weave fabric. The results show that there are obvious differences between the tensile property of a bi-axial warp knitted fabric and that of a plain weave fabric.The former can give fuller play to the property of a high modulus yarn than the latter. The tensile strength of a bi-axial warp knitted fabric is linear with the number of yarns in the direction of force.

  10. The axial charges of the hidden-charm pentaquark states

    CERN Document Server

    Wang, Guang-Juan; Zhu, Shi-Lin

    2016-01-01

    With the chiral quark model, we have calculated the axial charges of the pentaquark states with $(I,I_3)=(\\frac{1}{2},\\frac{1}{2})$ and $J^{P}=\\frac{1}{2}^{\\pm},\\frac{3}{2}^{\\pm},\\frac{5}{2}^{\\pm}$. The $P_c$ states with the same $J^P$ quantum numbers but different color-spin-flavor configurations have very different axial charges, which encode important information on their underlying structures. For some of the $J^{P}=\\frac{3}{2}^{\\pm}$ or $\\frac{5}{2}^{\\pm}$ pentaquark states, their axial charges are much smaller than that of the proton.

  11. Effects of external axial magnetic field on fast electron propagation

    International Nuclear Information System (INIS)

    A scheme employing an external axial magnetic field is proposed to diagnose the intrinsic divergence of laser-generated fast electron beams, and this is studied numerically with hybrid simulations. The maximum beam radius of fast electrons increases with the initial divergence and decreases with the amplitude of the axial magnetic field. It is indicated that the intrinsic divergence of fast electrons can be inferred from measurements of the beam radius at different depth under the axial field. The proposed scheme here may be useful for future fast ignition experiments and in other applications of laser-generated fast electron beams.

  12. Dynamic Analysis of Axial Magnetic Forces for DVD Spindle Motors

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The axial magnetic force, induced by the complicated flux linkage distribution from rotor magnet and stator slotted, is constructed by different relative heights and calculated by 3D finite element method (FEM) to analyze the dynamic characteristics for a DVD spindle motor. The axial magnetic force is designed to provide an axial stiffness and govern the natural frequency of the dynamic performance. According to the simulation results and experimental measurements, the dynamic behaviors are significantly improved with a variation of relative height of rotor magnet and stator slotted on a DVD spindle motor.

  13. A non-integral, axial-force measuring element

    Science.gov (United States)

    Ringel, M.; Levin, D.; Seginer, A.

    1989-10-01

    A new approach to the measurement of the axial force is presented. A nonintegral axial-force measuring element, housed within the wind-tunnel model, avoids the interactions that are caused by nonlinear elastic phenomena characteristic of integral balances. The new design overcomes other problems, such as friction, misalignment and relative motion between metric elements, that plagued previous attempts at separate measurement of the axial force. Calibration and test results prove the ability of the new approach to duplicate and even surpass the results of much more complicated and expensive integral balances. The advantages of the new design make it the best known solution for particular measurement problems.

  14. The application value of HLA-B27 detection in the diagnosis of spondyloarthritis%HLA-B27检测在脊柱关节炎诊断中的应用价值

    Institute of Scientific and Technical Information of China (English)

    姚玮

    2014-01-01

    Objective To analyze human leucocyte antigen B27(HLA-B27) diagnostic value in spondyloarthritis(SpA) .Methods Using flow cytometry to detect HLA-B27 expressions of 298 SpA patients(SpA group) and 195 non-SpA patients(non-SpA group) .Results 227 patients were positive in the 493 patients .In SpA group ,the positive rates of HLA-B27 expressing in ankylo-sing spondylitis (AS ) ,juvenile spondyloarthritis (JSpA ) ,reactive arthritis (ReA ) ,undifferentiated spondyloarthritis (USpA ) , psoriatic arthritis(PsA) were 87 .66% ,59 .09% ,58 .33% ,37 .18% ,25 .00% ,respectively .In non-SpA group ,the positive rates of HLA-B27 expressing in rheumatoid arthritis ,rheumatic arthritis ,cervical or lumbar disease ,osteoarthritis ,gouty arthritis were 18 . 18% ,17 .86% ,16 .67% ,11 .76% ,0 .00% ,respectively .The SpA group and the non-SpA group of HLA-B27 positive comparative differences was statistically significant(P<0 .01) .Conclusion The HLA-B27 is correlated with SpA ,and can provide reference for clinical diagnosis of SpA especially the AS .%目的:分析人类白细胞抗原B27(HLA-B27)在脊柱关节炎(SpA)中的诊断价值。方法采用流式细胞术检测298例SpA患者(SpA组)和195例非SpA患者(非SpA组)HLA-B27的表达水平。结果493例患者中,HLA-B27阳性227例。SpA组中强直性脊柱炎(AS)、幼年脊柱关节炎(JSpA)、反应性关节炎(ReA)、未分化型脊柱关节炎(USpA)和银屑病关节炎(PsA)患者的HLA-B27阳性率,分别为87.66%、59.09%、58.33%、37.18%、25.00%;非SpA组中类风湿关节炎、风湿性关节炎、颈椎或腰椎疾病、骨关节炎、痛风性关节炎患者的HLA-B27阳性率,分别为18.18%、17.86%、16.67%、11.76%、0.00%。SpA组与非SpA组HLA-B27阳性率比较差异有统计学意义(P<0.01)。结论HLA-B27与SpA密切相关,可为临床诊断SpA,尤其是AS提供参考。

  15. AXIAL: a system for boiling water reactor fuel assembly axial optimization using genetic algorithms

    International Nuclear Information System (INIS)

    A system named AXIAL is developed based on the genetic algorithms (GA) optimization method, using the 3D steady state simulator code Core-Master-PRESTO (CM-PRESTO) to evaluate the objective function. The feasibility of this methodology is investigated for a typical boiling water reactor (BWR) fuel assembly (FA). The axial location of different fuel compositions is found in order to minimize the FA mean enrichment needed to obtain the cycle length under the safety constraints. Thermal limits are evaluated at the end of cycle using the Haling calculation; the hot excess reactivity and the shutdown margin at the beginning of cycle are also evaluated. The implemented objective function is very flexible and complete, incorporating all the thermal and reactivity limits imposed during fuel design analysis; furthermore, additional constraints can be easily introduced in order to obtain an improved solution. The results show a small improvement in the FA average enrichment obtained with the system related to the reference case that has been studied. The results show that the system converge to an optimal solution, it is observed that the mean fuel enrichment decreases while all the constraints are satisfied. A comparison was also performed using one-point and two-points crossover operator and the results of a sensitivity study for different mutation percentage are also showed

  16. Time Domain Terahertz Axial Computed Tomography Non Destructive Evaluation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to demonstrate key elements of feasibility for a high speed automated time domain terahertz computed axial tomography (TD-THz CT) non destructive...

  17. Time Domain Terahertz Axial Computed Tomography Non Destructive Evaluation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase 2 project, we propose to develop, construct, and deliver to NASA a computed axial tomography time-domain terahertz (CT TD-THz) non destructive...

  18. Numerical analysis of cocurrent conical and cylindrical axial cyclone separators

    Science.gov (United States)

    Nor, M. A. M.; Al-Kayiem, H. H.; Lemma, T. A.

    2015-12-01

    Axial concurrent liquid-liquid separator is seen as an alternative unit to the traditional tangential counter current cyclone due to lower droplet break ups, turbulence and pressure drop. This paper presents the numerical analysis of a new conical axial cocurrent design along with a comparison to the cylindrical axial cocurrent type. The simulation was carried out using CFD technique in ANSYS-FLUENT software. The simulation results were validated by comparison with experimental data from literature, and mesh independency and quality were performed. The analysis indicates that the conical version achieves better separation performance compared to the cylindrical type. Simulation results indicate tangential velocity with 8% higher and axial velocity with 80% lower recirculation compared to the cylindrical type. Also, the flow visualization counters shows smaller recirculation region relative to the cylindrical unit. The proposed conical design seems more efficient and suits the crude/water separation in O&G industry.

  19. Energy Dissipation in Sandwich Structures During Axial Compression

    DEFF Research Database (Denmark)

    Urban, Jesper

    2002-01-01

    The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full......-scale structural elements in fast sandwich vessels. Two of the crushing tests are simulated with the explicit finite element software LS-DYNA3D. The key results are load-end shortening relationship and the energy dissipation. Good agreement between the numerical predictions and the experiments are obtained. A...... simple analytical model for the energy dissipation during axial crushing is proposed. Keywords: Sandwich, Energy Dissipation, Axial Crushing, LS-DYNA, Analytical crushing models, Crashworthiness....

  20. CT of posterior ocular staphyloma in axial myopia

    International Nuclear Information System (INIS)

    We present two cases of posterior ocular staphylomas in axial myopia. CT findings of an enlarged globe with focal posterior bulging and scleraluveal rim thinning appear to be specific for this diagnosis. (orig.)

  1. Effect of axial heat flux distribution on CHF

    International Nuclear Information System (INIS)

    Previous investigations for the effect of axial heat flux distributions on CHF and the prediction methods are reviewed and summarized. A total of 856 CHF data in a tube with a non-uniform axial heat flux distribution has been compiled from the articles and analyzed using the 1995 Groeneveld look-up table. The results showed that two representative correction factors, K5 of the look-up table and Tongs F factor, can be applied to describe the axial heat flux distribution effect on CHF. However, they overpredict slightly the measured CHF, depending on the quality and flux peak shape. Hence, a corrected K5 factor, which accounts for the axial heat flux distribution effect is suggested to correct these trends. It predicted the CHF power for the compiled data with an average error of 1.5% and a standard deviation of 10.3%, and also provides a reasonable prediction of CHF locations

  2. CT of posterior ocular staphyloma in axial myopia

    Energy Technology Data Exchange (ETDEWEB)

    Swayne, L.C.; Garfinkle, W.B.; Bennett, R.H.

    1984-05-01

    We present two cases of posterior ocular staphylomas in axial myopia. CT findings of an enlarged globe with focal posterior bulging and scleraluveal rim thinning appear to be specific for this diagnosis.

  3. The development of an axial active magnetic bearing / R. Gouws

    OpenAIRE

    Gouws, Rupert

    2004-01-01

    In this dissertation, the author presents the operation and development of active magnetic bearings (AMBs) , with specific focus on axial M s . The project objective is the development of an axial AMB system. The electromagnetic design, inductive sensor design, dSpace controller model design and actuating amplifier design are aspects discussed in this dissertation. The physical model constitutes two electromagnets positioned above and beneath a 2 kg steel disc with an air gap o...

  4. Design and Simulation of Axial Flow Maglev Blood Pump

    OpenAIRE

    Huachun Wu; Ziyan Wang; Xujun Lv

    2011-01-01

    The axial flow maglev blood pump (AFMBP) has become a global research focus and emphasis for artificial ventricular assist device, which has no mechanical contact, mechanical friction, compact structure and light weight, can effectively solve thrombus and hemolysis. Magnetic suspension and impeller is two of the important parts in the axial flow maglev blood pump, and their structure largely determines the blood pump performance. The research adopts electromagnetic and fluid finite element an...

  5. Radial breathing mode of carbon nanotubes subjected to axial pressure

    OpenAIRE

    Lei, Xiao-Wen; Ni, Qing-Qing; Shi, Jin-Xing; Natsuki, Toshiaki

    2011-01-01

    In this paper, a theoretical analysis of the radial breathing mode (RBM) of carbon nanotubes (CNTs) subjected to axial pressure is presented based on an elastic continuum model. Single-walled carbon nanotubes (SWCNTs) are described as an individual elastic shell and double-walled carbon nanotubes (DWCNTs) are considered to be two shells coupled through the van der Waals force. The effects of axial pressure, wave numbers and nanotube diameter on the RBM frequency are investigated in detail. Th...

  6. Nuclear Axial Currents in Chiral Effective Field Theory

    OpenAIRE

    Baroni, A.; Girlanda, L.; Pastore, S.; Schiavilla, R.; Viviani, M

    2015-01-01

    Two-nucleon axial charge and current operators are derived in chiral effective field theory up to one loop. The derivation is based on time-ordered perturbation theory, and accounts for cancellations between the contributions of irreducible diagrams and the contributions due to non-static corrections from energy denominators of reducible diagrams. Ultraviolet divergencies associated with the loop corrections are isolated in dimensional regularization. The resulting axial current is finite and...

  7. Axial myopia in computed and magnetic resonance tomography

    International Nuclear Information System (INIS)

    The case of a 44-year old woman suffering from amblyopia on the left eye with unilateral proptosis caused by axial (progressive) myopia is presented. The clinical and radiological findings were discussed in reference to the literature. The diagnosis was established by ruling out neoplastic, inflammatory or endocrine causes for the exophtalmos. CT and MR scans revealed an enlarged left globe without evidence of orbital masses. The findings were regarded as typical for the diagnosis at axial myopia. (orig.)

  8. Watson's theorem and the $N\\Delta(1232)$ axial transition

    CERN Document Server

    Alvarez-Ruso, L; Nieves, J; Vacas, M J Vicente

    2016-01-01

    We present a new determination of the $N\\Delta$ axial form factors from neutrino induced pion production data. For this purpose, the model of Hernandez et al., Phys. Rev. D76, 033005 (2007) is improved by partially restoring unitarity. This is accomplished by imposing Watson's theorem on the dominant vector and axial multipoles. As a consequence, a larger $C_5^A(0)$, in good agreement with the prediction from the off-diagonal Goldberger-Treiman relation, is now obtained.

  9. Volume Dependence of the Axial Charge of the Nucleon

    OpenAIRE

    Hall, N. L.; Thomas, A. W.; Young, R.D.(ARC Centre of Excellence for Particle Physics at the Terascale and CSSM, School of Chemistry and Physics, University of Adelaide, Adelaide, SA 5005, Australia); Zanotti, J. M.

    2012-01-01

    It is shown that the strong volume-dependence of the axial charge of the nucleon seen in lattice QCD calculations can be understood quantitatively in terms of the pion-induced interactions between neighbouring nucleons. The associated wave function renormalization leads to an increased suppression of the axial charge as the strength of the interaction increases, either because of a decrease in lattice size or in pion mass.

  10. Passive axial stabilization of a magnetic radial bearing by superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Marinescu, M.; Marinescu, N. (Ing.-Buro f. Magnettechnik, Mailander Str.19, D-6000 Frankfurt/M. 70 (DE)); Tenbrink, J.; Krauth, H. (Vacuumschmelze GmbH, Gruner Weg 37, D-6450 Hanau (DE))

    1989-09-01

    Contactless bearings for high-speed operation can be constructed using passive magnet systems, which inherently need a second, active bearing for their stabilization. Completely passive bearings only can be obtained using diamagnetic materials. This study deals with the axial stabilization of magnetic radial bearings using a permanent magnet/superconductor system. Using finite element calculation procedures it is shown that axial forces of up 3000 N and stiffnesses of up to 400 N/mm may be achieved.

  11. Organo-Axial Volvulus of the Stomach with Diaphragmatic Eventration

    OpenAIRE

    Lee, June Sung; Park, Jae Wan; Sohn, Jang Won; Kim, Kyung Chul; Hwang, Seong Gyu; Park, Pil Won; Rim, Kyu Sung; Kim, Hee Jin

    2000-01-01

    Gastric volvulus occurs when the stomach rotates about its longitudinal axis (organo-axial volvulus), or about an axis joining the lesser and greater curvatures (mesentero-axial volvulus). Primary gastric volvulus, making up one third of cases, occurs when the stabilizing ligaments are too lax as a result of congenital or acquired causes. Secondary gastric volvulus, making up the remainder of cases, occurs in association with a paraesophageal hernia or other congenital or acquired diaphragmat...

  12. Particle simulation of an improved axially extracted vircator

    International Nuclear Information System (INIS)

    An axially extracted virtual cathode oscillator (vircator) with a feedback annulus is proposed and configured through particle-in-cell (PIC) simulation. In this paper, the effects of the feedback mechanism are studied through PIC method. The simulated results indicate that the improved new vircator can increase the output power twice large than that of the axially-extracted conventional vircator under the same condition. On the other hand, it can narrow the bandwidth and purify the modes

  13. Particle Simulation of an Improved Axially Extracted Vircator

    Institute of Scientific and Technical Information of China (English)

    刘振祥; 舒挺; 张建德; 钱宝良

    2003-01-01

    An axially extracted virtual cathode oscillator (vircator) with a feedback annulusis proposed and configured through particle-in-cell (PIC) simulation in Ref. [1]. In this paper,the effects of the feedback mechanism are studied through PIC method. The simulated resultsindicate that the improved new vircator can increase the output power twice large than that ofthe axially-extracted conventional vircator under the same condition. On the other hand, it cannarrow the bandwidth and purify the modes.

  14. Axial Non-linear Dynamic Soil-Pile Interaction - Keynote

    OpenAIRE

    Holeyman A.; Whenham V.

    2014-01-01

    This keynote lecture describes recent analytical and numerical advances in the modeling of the axial nonlinear dynamic interaction between a single pile and its embedding soil. On one hand, analytical solutions are developed for assessing the nonlinear axial dynamic response of the shaft of a pile subjected to dynamic loads, and in particular to vibratory loads. Radial inhomogeneity arising from shear modulus degradation is evaluated over a range of parameters and compared with those obtained...

  15. The New Performance Calculation Method of Fouled Axial Flow Compressor

    OpenAIRE

    Huadong Yang; Hong Xu

    2014-01-01

    Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section in...

  16. Axial myopia in computed and magnetic resonance tomography

    Energy Technology Data Exchange (ETDEWEB)

    Beyer-Enke, S.A.; Goerich, J.; Gamroth, A.

    1987-08-01

    The case of a 44-year old woman suffering from amblyopia on the left eye with unilateral proptosis caused by axial (progressive) myopia is presented. The clinical and radiological findings were discussed in reference to the literature. The diagnosis was established by ruling out neoplastic, inflammatory or endocrine causes for the exophtalmos. CT and MR scans revealed an enlarged left globe without evidence of orbital masses. The findings were regarded as typical for the diagnosis at axial myopia.

  17. Axial Myopia and its Influence on Diabetic Retinopathy

    International Nuclear Information System (INIS)

    Objective: To evaluate the correlation between axial myopia and diabetic retinopathy. Study Design: Cross-sectional study. Place and Duration of Study: Eye Department of Postgraduate Medical Institute, Lahore General Hospital, from August 2012 to February 2013. Methodology: A total of 258 participants suffering from type-2 diabetic retinopathy were included. Axial length was measured by two optometrists using contact type ultrasound biometer. Colored retinal photographs, red free retinal photographs and Fundus Fluorescein Angiography (FFA) were performed on all patients using standard fundus camera. All fundus photographs and angiograms were independently reviewed and graded by two qualified vitreoretinal fellows. Results: Out of 258 patients, 163 were males (63.2%) and 95 (36.8%) were females. Average age of patients was 56.30 +- 7.57 years. Average axial length of right and left eyes were 23.16 mm and 23.15 mm respectively. There was statistically significant negative correlation between axial length and severity of diabetic retinopathy in the right eye, (Spearman correlation = -0.511, p = 0.0001) as well as the left eye (Spearman correlation = -0.522, p = 0.0001). Conclusion: There is a protective influence of longer axial length of globe on the stage and severity of diabetic retinopathy. This study may help in modifying the screening protocol for diabetic retinopathy amongst patients of differing axial lengths. (author)

  18. Difference between measured and predicted axial offset at NPP Krsko

    International Nuclear Information System (INIS)

    At NPP Krsko axial power distribution is monitored through periodic measurements of the AO (axial offset). AO represents the normalized power difference between top and bottom of the core. Within the core design process predicted values of axial offset (P-AO) for the entire core lifetime are calculated. During the core performance surveillance measured AO (M-AO) is compared to the predicted value. Measured vs. predicted axial offset difference (D-AO) of +3% at hot-full-power (HFP) steady-state core conditions is considered to be within measurement and design tolerances. During the last two 18 months cycles increase in the D-AO above 3 % was experienced for limited period of time at NPP Krsko - in cycle 22 for more than 90 EFPD (Effective Full Power Days). For such deviation evaluation has to be performed to confirm that reload safety evaluation and analysis of the core has not been impacted. Root cause analysis was performed afterwards and it was classified as a core design computer code deficiency. Precisely, inadequate axial actinides treatment in the computer code contributed to the observed axial offset difference. (author)

  19. Superfluid phase stability of 3He in axially anisotropic aerogel

    International Nuclear Information System (INIS)

    Measurements of superfluid 3He in 98% aerogel demonstrate the existence of a metastable A-like phase and a stable B-like phase. It has been suggested that the relative stability of these two phases is controlled by anisotropic quasiparticle scattering in the aerogel. Anisotropic scattering produced by axial compression of the aerogel has been predicted to stabilize the axial state of superfluid 3He. To explore this possibility, we used transverse acoustic impedance to map out the phase diagram of superfluid 3He in a ∼ 98% porous silica aerogel subjected to 17% axial compression. We have previously shown that axial anisotropy in aerogel leads to optical birefringence and that optical cross-polarization studies can be used to characterize such anisotropy. Consequently, we have performed optical cross-polarization experiments to verify the presence and uniformity of the axial anisotropy in our aerogel sample. We find that uniform axial anisotropy introduced by 17% compression does not stabilize the A-like phase. We also find an increase in the supercooling of the A-like phase at lower pressure, indicating a modification to B-like phase nucleation in globally anisotropic aerogels.

  20. Axial rotation in rat embryos: involvement of changes in the shapes and arrangement of cells.

    Science.gov (United States)

    Matsuda, M; Yasutomi, M

    1995-02-01

    Rat embryos at the head-fold stage (9.5 days of gestation) were cultured for 32 hours in rat serum. Embryos rotated their axes (changing from the shape of a concave mid-region to that of a convex mid-region) during the last 5 hours of culture (from 27 h to 32 h in culture). Addition of 0.1 micrograms/ml cytochalasin D to the culture medium for this 5-hour period prevented axial rotation in the embryos and disturbed the appearance of microfilaments in the dermatome, the dorsal region of the trunk neural tube, and the dorsal epidermis. During the period of axial rotation, the dermatome and the dorsal epidermis extended and showed the arrangement of microfilaments along the cranio-caudal axis in the control embryos but not in the treated embryos. The dorsal region of the trunk neural tube in the control embryos consisted of a seam of neuroepithelial cells in which microfilaments were apparently arranged along the cranio-caudal axis but the region in the treated embryos was crowded with the neuroepithelial cells piled up randomly and microfilaments showed no arrangement. These results suggest that changes in the shapes and arrangement of the cells in the dermatome, the dorsal region of the trunk neural tube, and the dorsal epidermis cause extension of these tissues along the cranio-caudal axis and result in axial rotation. Microfilaments may play an essential role in changes in the shapes and arrangement of the cells in these tissues. PMID:7796462

  1. Atomic states and collisional relaxation in plasma polarization spectroscopy: axially symmetric case

    International Nuclear Information System (INIS)

    An ensemble of atoms (or ions) is described in terms of the density matrix, and two quantities, population and alignment, are assigned to each atomic level for axially symmetric plasma environment. Collisional relaxation is treated semiclassically as transitions between vectors in the Liouville space and interpreted as elastic or inelastic transitions among the population and the alignment of the levels. A spatially anisotropic velocity distribution of perturbers is expanded in terms of Legendre polynomials, and rate coefficients are defined for the transitions. A set of rate equations are constructed for the system of populations and another set for that of alignments. In the case of an isotropic Maxwellian distribution of perturbers the former reduces to the conventional collisional-radiative model describing the ionizing plasma component of populations. As an example, berylliumlike oxygen in an anisotropic plasma environment is treated by this method. (author)

  2. Investigation of axial power gradients near a control rod tip

    International Nuclear Information System (INIS)

    Highlights: → Pin power gradients near BWR control rod tips have been investigated. → A control rod tip is modeled in MCNP and compared to simplified 2D/3D geometry. → Small nodes increases pin power gradients; standard nodes underestimates gradients. → The MCNP results are validated against axial gamma scan of a controlled fuel pin. - Abstract: Control rod withdrawal in BWRs induces large power steps in the adjacent fuel assemblies. This paper investigates how well a 2D/3D method, e.g., CASMO5/SIMULATE5 computes axial pin power gradients adjacent to an asymmetrical control-rod tip in a BWR. The ability to predict pin power gradients accurately is important for safety considerations whereas large powers steps induced by control rod withdrawal can cause Pellet Cladding Interaction. The computation of axial pin power gradients axially around a control rod tip is a challenging task for any nodal code. On top of that, asymmetrical control rod handles are present in some BWR designs. The lattice code CASMO requires diagonal symmetry of all control rod parts. This introduces an error in computed pin power gradients that has been evaluated by Monte Carlo calculations. The results show that CASMO5/SIMULATE5, despite the asymmetrical control rod handle, is able to predict the axial pin power gradient within 1%/cm for axial nodal sizes of 15-3.68 cm. However, a nodal size of 3.68 cm still causes underestimations of pin power gradients compared with 1 cm nodes. Furthermore, if conventional node sizes are used, ∼15 cm, pin power gradients can be underestimated by over 50% compared with 1 cm nodes. The detailed axial pin power profiles from MCNP are corroborated by measured gamma scan data on fuel rods irradiated adjacent to control rods.

  3. An Axial Vector Photon in a Mirror World

    CERN Document Server

    Sharafiddinov, Rasulkhozha S

    2015-01-01

    The unity of symmetry laws emphasizes, in the case of a mirror CP-even Dirac Lagrangian, the ideas of the left- and right-handed axial-vector photons referring to long- and short-lived bosons of true neutrality, respectively. Such a difference in lifetimes expresses the unidenticality of masses, energies and momenta of axial-vector photons of the different components. They define the unified field theory equation of C-odd particles with an integral spin. Together with a new equation of a theory of truly neutral particles with the half-integral spin, the latter reflects the availability in their nature of the second type of the local axial-vector gauge transformation responsible for origination in the Lagrangian of C-oddity of an interaction Newton component giving an axial-vector mass to all the interacting particles and fields. The mirror axial-vector mass, energy and momentum operators constitute a CP-invariant equation of quantum mechanics, confirming that each of them can individually influence on matter ...

  4. Rotordynamics of Turbine Labyrinth Seals with Rotor Axial Shifting

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Rotors in high-performance steam turbines experience a significant axial shifting during starting and stopping processes due to thermal expansion, for example. This axial shifting could significantly alter the flow pattern and the flow-induced rotordynamic forces in labyrinth seals, which in turn, can considerably affect the rotor-seal system performance. This paper investigates the influence of the rotor axial shifting on leakage rate as well as rotordynamic forces in high-low labyrinth seals over a range of seal clearances and inlet swirl velocities. A well-established CFD-perturbation model was employed to predict the rotordynamic coefficients. A surprisingly large effect was detected for rotordynamic characteristics due to rotor shifting. It was also found that a less destabilizing effect arose from rotor axial shifting in the leakage flow direction, whereas a more destabilizing effect arose from shifting against the leakage flow direction. Further, a tentative explanation was proposed for the large sensitivities of dynamic forces to rotor axial shifting.

  5. Rotordynamics of Turbine Labyrinth Seals with Rotor Axial Shifting

    Directory of Open Access Journals (Sweden)

    David L. Rhode

    2006-03-01

    Full Text Available Rotors in high-performance steam turbines experience a significant axial shifting during starting and stopping processes due to thermal expansion, for example. This axial shifting could significantly alter the flow pattern and the flow-induced rotordynamic forces in labyrinth seals, which in turn, can considerably affect the rotor-seal system performance. This paper investigates the influence of the rotor axial shifting on leakage rate as well as rotordynamic forces in high-low labyrinth seals over a range of seal clearances and inlet swirl velocities. A well-established CFD-perturbation model was employed to predict the rotordynamic coefficients. A surprisingly large effect was detected for rotordynamic characteristics due to rotor shifting. It was also found that a less destabilizing effect arose from rotor axial shifting in the leakage flow direction, whereas a more destabilizing effect arose from shifting against the leakage flow direction. Further, a tentative explanation was proposed for the large sensitivities of dynamic forces to rotor axial shifting.

  6. Artery Remodeling Under Axial Twist in Three Days Organ Culture.

    Science.gov (United States)

    Wang, Guo-Liang; Xiao, Yangming; Voorhees, Andrew; Qi, Ying-Xin; Jiang, Zong-Lai; Han, Hai-Chao

    2015-08-01

    Arteries often endure axial twist due to body movement and surgical procedures, but how arteries remodel under axial twist remains unclear. The objective of this study was to investigate early stage arterial wall remodeling under axial twist. Porcine carotid arteries were twisted axially and maintained for three days in ex vivo organ culture systems while the pressure and flow remained the same as untwisted controls. Cell proliferation, internal elastic lamina (IEL) fenestrae shape and size, endothelial cell (EC) morphology and orientation, as well as the expression of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, and tissue inhibitor of metalloproteinase-2 (TIMP-2) were quantified using immunohistochemistry staining and immunoblotting. Our results demonstrated that cell proliferation in both the intima and media were significantly higher in the twisted arteries compared to the controls. The cell proliferation in the intima increased from 1.33 ± 0.21% to 7.63 ± 1.89%, and in the media from 1.93 ± 0.84% to 8.27 ± 2.92% (p culture, a decrease from the initial 15.58 ± 1.29 degrees. These results demonstrate that axial twist can stimulate artery remodeling. These findings complement our understanding of arterial wall remodeling under mechanical stress resulting from pressure and flow variations. PMID:25503524

  7. Method to measure tone of axial and proximal muscle.

    Science.gov (United States)

    Gurfinkel, Victor S; Cacciatore, Timothy W; Cordo, Paul J; Horak, Fay B

    2011-01-01

    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention. PMID:22214974

  8. An Axial-Vector Photon in a Mirror World

    Science.gov (United States)

    Sharafiddinov, Rasulkhozha S.

    2016-03-01

    The unity of symmetry laws emphasizes, in the case of a mirror CP-even Dirac Lagrangian, the ideas of the left- and right-handed axial-vector photons referring to long- and short-lived bosons of true neutrality, respectively. Such a difference in lifetimes expresses the unidenticality of masses, energies and momenta of axial-vector photons of the different components. They define the unified field theory equation of C-odd particles with an integral spin. Together with a new equation of a theory of truly neutral particles with the half-integral spin, the latter reflects the availability in their nature of the second type of the local axial-vector gauge transformation responsible for origination in the Lagrangian of C-oddity of an interaction Newton component giving an axial-vector mass to all the interacting particles and fields. The mirror axial-vector mass, energy and momentum operators constitute a CP-invariant equation of quantum mechanics, confirming that each of them can individually influence on matter field. Thereby, findings suggest at the level of the mass-charge structure of gauge invariance a new equation for the C-noninvariant Lagrangian.

  9. STED microscopy based on axially symmetric polarized vortex beams

    Science.gov (United States)

    Zhehai, Zhou; Lianqing, Zhu

    2016-03-01

    A stimulated emission depletion (STED) microscopy scheme using axially symmetric polarized vortex beams is proposed based on unique focusing properties of such kinds of beams. The concept of axially symmetric polarized vortex beams is first introduced, and the basic principle about the scheme is described. Simulation results for several typical beams are then shown, including radially polarized vortex beams, azimuthally polarized vortex beams, and high-order axially symmetric polarized vortex beams. The results indicate that sharper doughnut spots and thus higher resolutions can be achieved, showing more flexibility than previous schemes based on flexible modulation of both phase and polarization for incident beams. Project supported by the National Natural Science Foundation of China (Grant Nos. 61108047 and 61475021), the Natural Science Foundation of Beijing, China (Grant No. 4152015), the Program for New Century Excellent Talents in Universities of China (Grant No. NCET-13-0667), and the Top Young Talents Support Program of Beijing, China (Grant No. CIT&TCD201404113).

  10. Identification du comportement de composites en fatigue bi-axiale

    OpenAIRE

    Busca, Damien

    2014-01-01

    La connaissance du comportement de composites sous un état de contraintes multi-axial reste un enjeu majeur pour l’optimisation du dimensionnement des structures. La machine de fatigue bi-axiale présente au LGP permet de générer un état de contrainte bi-axial par l’utilisation d’éprouvettes cruciformes. La conception des éprouvettes reste un enjeu majeur pour les chercheurs pour répondre aux problèmes spécifiques liés aux matériaux composites. Un nouveau type d’éprouvette cruciforme en compos...

  11. Liquid Axial Mixing in Packed Tower at Elevated Pressure

    Institute of Scientific and Technical Information of China (English)

    唐忠利; 张鹏; 等

    2003-01-01

    Liquid phase axial mixing was measured with the tracer technique in a packed column with inner diameter of 0.15m,in which the structured packing,Mellapak 350Y,was installed.Tap water as the liquid phase flowed down through the column and stagnant gas was at elevated pressure ranging from atmospheric to 2.0MPa.The model parameters of Bo andθwere estimated with the least square method in the time domain.As liquid flow rate was increased,the liquid axial mixing decreased.under our experimental conditions,the effect of pressure on Bo number on single liquid phase was negligible,and eddy diffusion was believed to be the primary cause of axial mixing in liquid phase.

  12. Axial Shock in a Cylindrical Plasma with Current

    International Nuclear Information System (INIS)

    Hugoniot relations of a two-dimensional axial shock with current and magnetic field in a cylindrical shock tube were investigated by a numerical method. The radial profiles of the magnetic field, electric current, pressures, flow velocities and temperatures between the up- and down-stream radial force-balanced plasma of the shock were revealed by numerical analysis. It is clearly found that the axial shock can lead to two effects: one is an inverse skin effect (i.e., the current density rises towards the center of the conductor), the another is a reversed current effect which occurs near the edge and about a half radius. It is also found that the radial gradient of pressure, density and temperature all become very large near the center due to the axial shock

  13. Ball Screw Actuator Including an Axial Soft Stop

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Forrest, Steven Talbert (Inventor); Abel, Steve (Inventor); Woessner, George (Inventor); Hanlon, Casey (Inventor)

    2016-01-01

    An actuator includes an actuator housing, a ball screw, and an axial soft stop assembly. The ball screw extends through the actuator housing and has a first end and a second end. The ball screw is coupled to receive a drive force and is configured, upon receipt of the drive force, to selectively move in a retract direction and an extend direction. The axial soft stop assembly is disposed within the actuator housing. The axial soft stop assembly is configured to be selectively engaged by the ball screw and, upon being engaged thereby, to translate, with compliance, a predetermined distance in the extend direction, and to prevent further movement of the ball screw upon translating the predetermined distance.

  14. Fast imaging of mean, axial and radial diffusion kurtosis

    DEFF Research Database (Denmark)

    Hansen, Brian; Shemesh, Noam; Jespersen, Sune Nørhøj

    2016-01-01

    benefit from more efficient acquisition and computational methods. To meet this demand, we recently developed a method capable of estimating mean kurtosis with only 13 diffusion weighted images. This approach was later shown to provide very accurate mean kurtosis estimates and to be more efficient in...... terms of contrast to noise per unit time. However, insofar, the computation of two other critical DKI parameters, radial and axial kurtosis, has required the estimation of all 22 variables parameterizing the full DKI signal expression. Here, we present two strategies for estimating all of DKI......'s principal parameters – mean kurtosis, radial kurtosis, and axial kurtosis – using only 19 diffusion weighted images, compared to the current state-of-the-art acquisitions typically requiring about 60 images. The first approach is based on axially symmetric diffusion and kurtosis tensors, presented here for...

  15. Modified approach for calculating axial vector vacuum susceptibility

    International Nuclear Information System (INIS)

    We generalize our previous work [Phys. Rev. C 72, 035202 (2005)] on the linear response theory of the dressed quark propagator in the presence of a constant external field to the case of a variable external field in order to make it applicable to a wider class of problems. Using the axial vector vacuum susceptibility as an illustration, we apply this general formalism to extract a new expression for the axial vector vacuum susceptibility in the quantum chromodynamical (QCD) sum rule two-point external field formula. The numerical values of the axial vector vacuum susceptibility are calculated within the framework of the rainbow-ladder approximation of the Dyson-Schwinger approach. A comparison with the results of the previous approaches is given

  16. Numerical analysis of cavitation within slanted axial-flow pump

    Institute of Scientific and Technical Information of China (English)

    张睿; 陈红勋

    2013-01-01

    In this paper, the cavitating flow within a slanted axial-flow pump is numerically researched. The hydraulic and cavitation performance of the slanted axial-flow pump under different operation conditions are estimated. Compared with the experimental hydraulic performance curves, the numerical results show that the filter-based model is better than the standard k-e model to predict the parameters of hydraulic performance. In cavitation simulation, compared with the experimental results, the proposed numerical method has good predicting ability. Under different cavitation conditions, the internal cavitating flow fields within slanted axial-flow pump are investigated. Compared with flow visualization results, the major internal flow features can be effectively grasped. In order to explore the origin of the cavitation performance breakdown, the Boundary Vorticity Flux (BVF) is introduced to diagnose the cavitating flow fields. The analysis results indicate that the cavitation performance drop is relevant to the instability of cavitating flow on the blade suction surface.

  17. The small axial charge of the N(1535) resonance

    CERN Document Server

    an, C S

    2008-01-01

    There is a natural cancellation between the contributions of the $qqq$ and $qqqq\\bar q$ components to the axial charge of the N(1535) resonance. While the probability of the former is larger than that of the latter, its coefficient in the axial charge expression is exceptionally small. The magnitude of two of the corresponding coefficients of the $qqqq\\bar q$ components are in contrast large and have the opposite sign. This result provides a phenomenological illustration of the recent unquenched lattice calculation result that the axial charge of the N(1535) resonance is very small, if not vanishing \\cite{takah}. The result sets an upper limit on the magnitude of the probability of $qqqq\\bar q$ components as well.

  18. Optimum axial flow taper in a countercurrent gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Von Halle, E.

    1979-02-01

    The effect of an axially varying countercurrent circulation rate in a gas centrifuge on the efficiency factors, e/sub I/, the ideality efficiency, and e/sub C/, the circulation efficiency, is investigated and compared with the case in which the countercurrent circulation rate is constant throughout the centrifuge. The optimum variation of the centrifuge parameter m, which is a measure of the countercurrent circulation rate, as a function of axial position in the centrifuge is determined. It is shown that when the countercurrent circulation rate has its optimum value at every axial position in the centrifuge, the product of the efficiency factors, e/sub I/ x e/sub C/, can exceed 81 per cent, the nominal upper limit of the value of the product of the efficiency factors for a constant countercurrent circulation rate, and can be quite close to unity. This is illustrated by numerical examples based on a centrifuge previously described in the literature.

  19. Twenty axial level handling in the APOSTOL code

    International Nuclear Information System (INIS)

    In many high-resolution calculation it has been proved that, in assemblies beside the control rod the pin-wise linear heat rate is different from linear heat rate calculated by pin-wise diffusion codes using only ten axial level code. In the linear heat rate of these assemblies there is a positive peak beside the intermediate part of control rod, which is the connection between the absorber and the fuel. In the ten level calculation cases this peak is not observable because of the homogenisation of the levels. Therefore more detailed axial division has to be used for the calculations. In this paper it is presented the application of a twenty axial level division in the APOSTOL code. It is presented the geometry of the nodes and the calculation of the cross sections of the nodes. Furthermore, the twenty level handling in the APOSTOL code is described. The same calculation result in realistic cases are presented. (author)

  20. Electromagnetic and axial structures of Baryon ground and resonant states

    International Nuclear Information System (INIS)

    This thesis is devoted to the investigation of the electroweak structures of baryons. One performs a comprehensive study of the electromagnetic and axial form factors of baryon ground states with flavors 'up', 'down', and 'strange'; regarding baryon resonances the axial charges are investigated. The dynamics for the description of baryons is furnished by the relativistic constituent-quark model, of which three different variants are applied here. The calculations are performed in the framework of relativistic quantum mechanics, where the electromagnetic and axial current operators are constructed along a spectator model in the point-form.While the evaluations of the electroweak form factors are based on an already established formalism, one develops a generally valid formulation for the axial charges. Thereby it becomes possible to calculate these quantities for arbitrary baryon states and completely general interaction models.It turns out that relativistic constituent-quark models can describe in the framework of a Poincare-invariant formalism not only the electromagnetic but also the axial form factors, which are calculated here for the first time for all baryons. Globally, a good agreement with experiment is achieved up to momentum transfers of about 4 GeV/c. With regard to the particularly sensitive quantities, like the electric radii and magnetic moments, the constituent-quark model based on Goldstone-boson exchange yields the best results. In cases, where no experimental data exist, the predictions agree well with results from lattice quantum chromodynamics. The analogue is true for the axial charges of baryon ground and resonant states. Except for some special cases, their values are presented here for the first time comprehensively and consistently. (author)

  1. A three-dimensional nodal method with Channel-wise Intrinsic Axial Mesh Adaptation

    International Nuclear Information System (INIS)

    Highlights: • CIAMA solves axial heterogeneity without iterative node re-homogenization. • CIAMA can easily resolve the control rod cusping problem. • CIAMA result shows great potential for 3-D pin-by-pin calculation. - Abstract: In a conventional coarse mesh nodal method the more accurate treatment of intra-nodal axial heterogeneity requires iterative axial node re-homogenization using axial flux profiles either reconstructed from core-wise coarse mesh solution or obtained from channel-wise axial fine mesh calculation. In this paper a new nodal method formulation, using Channel-wise Intrinsic Axial Mesh Adaptation (CIAMA), is proposed to solve this problem in a more fundamental way. For a given transverse (radial) leakage, along each axial channel a rigorous sub-node heterogeneous calculation is performed with the explicit axial heterogeneity within each coarse axial node. However, the transverse leakage between the axial channels is still calculated on the basis of coarse axial nodes, using the axially averaged radial current in each coarse axial node. Since the coupling between the axial channels is through the coarse axial nodes, it is not necessary to match the boundaries of the axial sub-nodes of neighboring axial channels in order to incorporate the axial sub-node calculation as an intrinsic part of the whole core global calculation. Therefore in the CIAMA nodal method, each axial channel is allowed to have its own sub-nodes adapting to its own axial heterogeneity variation. The CIAMA method has been implemented in the commercial code EGRET, which is used to qualify CIAMA. Excellent results of modeling fuel grid and control rod movement are presented. Application of CIAMA to three-dimensional pin-by-pin core calculation is also discussed and demonstrated to work well

  2. A simple approach to the ABJ axial anomaly

    International Nuclear Information System (INIS)

    A very simple semi-quantitative derivation of the Adler-Bell-Jackiw (ABJ) axial anomaly is given, based on an investigation of the absorptive part of the VVA triangle graph and dispersion relations. Essential ingredients of our discussion are: normal Ward identities for the absorptive part of the relevant diagram, dimensional analysis, unitarity, and energy-momentum conservation. An explanation of the physical origin of axial anomaly, proposed in some earlier treatments within such a dispersive framework, is critically examined. In particular, the interpretation of the ABJ anomaly as an analogy of the Lee-Nauenberg effect occurring in the massless limit of spinor electrodynamics is shown to be fallacious

  3. Axial-symmetrical domain structures in ferrite-garnet films

    International Nuclear Information System (INIS)

    Applying the improved technique of double ultrahigh-speed photography one studied occurrence and progress of domain structure upon magnetization of a small section of (BiLaTm)3(FeGa)5O12 ferrite-garnet film prior to saturation. The radial deformation affecting the specimen on the magnetized coil side was determined to break single-axis anisotropy resulting in occurrence of axial-oriented band domain structure inside the magnetized range. That structure period reduced with growth of the pulse field amplitude. Band axial-oriented domain structure is formed under the effect of the magnetostatic axisymmetric field

  4. Vector and axial currents in Wilson chiral perturbation theory

    International Nuclear Information System (INIS)

    We reconsider the construction of the vector and axial-vector currents in Wilson Chiral Perturbation Theory, the low-energy effective theory for lattice QCD with Wilson fermions. We discuss in detail the finite renormalization of the currents that has to be taken into account in order to properly match the currents. We explicitly show that imposing the chiral Ward identities on the currents does, in general, affect the axial-vector current at O(a). As an application of our results we compute the pion decay constant to one loop in the two-flavor theory. Our result differs from previously published ones.

  5. Instability of Meridional Axial System in f(R) Gravity

    CERN Document Server

    Sharif, M

    2015-01-01

    We analyze dynamical instability of non-static reflection axial stellar structure by taking into account generalized Euler's equation in metric $f(R)$ gravity. Such an equation is obtained by contracting Bianchi identities of usual anisotropic and effective stress-energy tensors, which after using radial perturbation technique gives modified collapse equation. In the realm of $R+\\epsilon R^n$ gravity model, we investigate instability constraints at Newtonian and post-Newtonian approximations. We find that instability of meridional axial self-gravitating system depends upon static profile of structure coefficients while $f(R)$ extra curvature terms induce stability to the evolving celestial body.

  6. The gravitational axial superfield and the formalism of differential geometry

    International Nuclear Information System (INIS)

    The formalism of differential geometry in the physical 4+4-dimensional superspace (SS) is developed on the basis of the simplest supergravity group of general transformations of the coordinates of the left and right chiral SS. In this formalism the only independent dynamical variable is the axial gravitational superfield (SF). All the geometrical objects - supertetrades, affinities, etc. - are expressed in terms of the axial gravitational SF. Analysis of the transformation properties of the spinor-coordinate derivatives has led to a natural definition of the local Lorentz group for SF. The simplest Lagrangian for pure supergravity is discussed

  7. Axial crack propagation and arrest in pressurized fuselage

    Science.gov (United States)

    Kosai, M.; Shimamoto, A.; Yu, C.-T.; Walker, S. I.; Kobayashi, A. S.; Tan, P.

    1994-01-01

    The crack arrest capability of a tear strap in a pressurized precracked fuselage was studied through instrumented axial rupture tests of small scale models of an idealized fuselage. Upon pressurization, rapid crack propagation initiated at an axial through crack along the stringer and immediately kinked due to the mixed modes 1 and 2 state caused by the one-sided opening of the crack flap. The diagonally running crack further turned at the tear straps. Dynamic finite element analysis of the rupturing cylinder showed that the crack kinked and also ran straight in the presence of a mixed mode state according to a modified two-parameter crack kinking criterion.

  8. Experimental investigation on ducted counter-rotating axial flow fans

    OpenAIRE

    Nouri, Hussain; Ravelet, Florent; Bakir, Farid; Sarraf, Christophe

    2011-01-01

    An experimental study on counter-rotating axial-flow fans was carried out. The fans of diameter D = 375 mm were designed using an inverse method. The counter-rotating fans operate in a ducted-flow configuration and the overall performances are measured in a normalized test bench. The rotation rate of each fan is independently controlled. The axial spacing between the fans can vary from 10 to 50 mm by steps of 10 mm. The results show that the efficiency is strongly increased compared to a conv...

  9. An effective theory for QCD with an axial chemical potential

    CERN Document Server

    Andrianov, Alexander A; Espriu, Domenec; Planells, Xumeu

    2013-01-01

    We consider the low energy realization of QCD in terms of meson fields when an axial chemical potential is present; a situation that may be relevant in heavy ion collisions. We shall demonstrate that the presence of an axial charge constitutes an explicit source of parity breaking. The eigenstates of strong interactions do not have a definite parity and interactions that would otherwise be forbidden compete with the familiar ones. In this work, we first focus on scalars and pseudoscalars that are described by a generalized linear sigma model; and next, we give some hints on how the Vector Meson Dominance model describes the vector sector.

  10. Infrared and terahertz radiation of a crystal at axial channeling

    International Nuclear Information System (INIS)

    Basic properties of radiation of a crystal lattice excited by an axial channeling particle are considered. It is shown that a coherent radiation of atoms occurs if the frequency of oscillations of the channeled particle comes to a resonance with the vibrational mode of the crystal. Spectral and angular distribution of radiation and its polarization are calculated. In case of a relativistic channeled particle, the radiation of atoms is generated into a narrow cone in the direction of a crystallographic axis along which the particle is channeling. The radiation of atoms exited at axial channelling has significant degree of circular polarization

  11. Buckling localization in a cylindrical panel under axial compression

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Needleman, A.

    2000-01-01

    Localization of an initially periodic buckling pattern is investigated for an axially compressed elastic-plastic cylindrical panel of the type occurring between axial stiffeners on cylindrical shells. The phenomenon of buckling localization and its analogy with plastic flow localization in tensile......, but where subsequently the load starts to increase again, it is found that near the local load minimum, the buckling pattern switches back to a periodic type of pattern. The inelastic material behavior of the panel is described in terms of J(2) corner theory, which avoids the sometimes unrealistically...

  12. Spectral analysis in thin tubes with axial heterogeneities

    KAUST Repository

    Ferreira, Rita

    2015-01-01

    In this paper, we present the 3D-1D asymptotic analysis of the Dirichlet spectral problem associated with an elliptic operator with axial periodic heterogeneities. We extend to the 3D-1D case previous 3D-2D results (see [10]) and we analyze the special case where the scale of thickness is much smaller than the scale of the heterogeneities and the planar coefficient has a unique global minimum in the periodic cell. These results are of great relevance in the comprehension of the wave propagation in nanowires showing axial heterogeneities (see [17]).

  13. Temperature dependant polycrystal model application to bainitic steel behavior under tri-axial loading in the ductile-brittle transition

    International Nuclear Information System (INIS)

    A polycrystal finite element (FE) model describing the temperature evolution of low carbon steel is proposed in order to forecast the local mechanical fields as a function of temperature, for bainitic microstructure submitted to tri-axial loading. The model is designed for finite strains, large lattice rotations and temperatures ranging into the brittle-ductile transition domain. The dislocation densities are the internal variables. At low temperature in Body Centred Cubic (BCC) materials, plasticity is governed by double kink nucleation of screw dislocations, whereas at high temperature, plasticity depends on interactions between mobile dislocations and the forest dislocations. In this paper, the constitutive law and the evolution of the dislocation densities are written as a function of temperature and describe low and high temperature mechanisms. The studied aggregates are built from Electron Back Scattering Diffraction (EBSD) images of real bainitic steel. The aggregate is submitted to a tri-axial loading in order to describe the material at a crack tip. Mechanical parameters are deduced from mechanical tests. The local strain and stress fields, computed for different applied loadings, present local variations which depend on temperature and on tri-axial ratio. The distribution curves of the maximal principal stresses show that heterogeneities respectively increase with temperature and decrease with tri-axial ratio. A direct application of this model provides the evaluation of the rupture probability within the aggregate, which is treated as the elementary volume in the weak link theory. A comparison with the Beremin criterion calibrated on experimental data, shows that the computed fracture probability dispersion induced by the stress heterogeneities is of the same order than the measured dispersion. Temperature and stress tri-axiality ratio effects are also investigated. It is shown that these two parameters have a strong effect on fracture owing to their

  14. Percutaneous pedicle screw reduction and axial presacral lumbar interbody fusion for treatment of lumbosacral spondylolisthesis: A case series

    Directory of Open Access Journals (Sweden)

    Miller Larry E

    2011-09-01

    Full Text Available Abstract Introduction Traditional surgical management of lumbosacral spondylolisthesis is technically challenging and is associated with significant complications. The advent of minimally invasive surgical techniques offers patients treatment alternatives with lower operative morbidity risk. The combination of percutaneous pedicle screw reduction and an axial presacral approach for lumbosacral discectomy and fusion offers an alternative procedure for the surgical management of low-grade lumbosacral spondylolisthesis. Case presentation Three patients who had L5-S1 grade 2 spondylolisthesis and who presented with axial pain and lumbar radiculopathy were treated with a minimally invasive surgical technique. The patients-a 51-year-old woman and two men (ages 46 and 50-were Caucasian. Under fluoroscopic guidance, spondylolisthesis was reduced with a percutaneous pedicle screw system, resulting in interspace distraction. Then, an axial presacral approach with the AxiaLIF System (TranS1, Inc., Wilmington, NC, USA was used to perform the discectomy and anterior fixation. Once the axial rod was engaged in the L5 vertebral body, further distraction of the spinal interspace was made possible by partially loosening the pedicle screw caps, advancing the AxiaLIF rod to its final position in the vertebrae, and retightening the screw caps. The operative time ranged from 173 to 323 minutes, and blood loss was minimal (50 mL. Indirect foraminal decompression and adequate fixation were achieved in all cases. All patients were ambulatory after surgery and reported relief from pain and resolution of radicular symptoms. No perioperative complications were reported, and patients were discharged in two to three days. Fusion was demonstrated radiographically in all patients at one-year follow-up. Conclusions Percutaneous pedicle screw reduction combined with axial presacral lumbar interbody fusion offers a promising and minimally invasive alternative for the management

  15. Pion electroproduction, partially conserved axial-vector current, chiral Ward identities, and the axial form factor revisited

    International Nuclear Information System (INIS)

    We reinvestigate Adler's partially conserved axial-vector current relation in the presence of an external electromagnetic field within the framework of QCD coupled to external fields. We discuss pion electroproduction within a tree-level approximation to chiral perturbation theory and explicitly verify a chiral Ward identity referred to as the Adler-Gilman relation. We critically examine soft-momentum techniques and point out how inadmissable approximations may lead to results incompatible with chiral symmetry. As a result we confirm that threshold pion electroproduction is indeed a tool to obtain information on the axial form factor of the nucleon

  16. The effect of residual axial gravity on the stability of liquid columns subjected to electric fields

    Science.gov (United States)

    Gonzalez, Heliodoro; Castellanos, Antonio

    1993-04-01

    The stability criterion for almost cylindrical dielectric liquid bridges subjected to axial electric fields in the presence of residual axial gravity is obtained. In its absence, a perfectly cylindrical equilibrium solution is allowed for all values of the relevant parameters, which are the slenderness of the liquid bridge, the electrical Bond number and the relative permittivity between the outer and inner media. This basic solution is unstable beyond a critical slenderness which varies with the electrical parameters (Gonzalez et al. 1989). The destabilization takes place axisymmetrically. The inclusion of the gravitational Bond number as a new, small parameter may be treated by means of the Liapunov-Schmidt Method, a well-known projection technique that gives the local bifurcation diagram relating the admissible equilibrium amplitudes for the liquid bridge and the aforementioned parameters. As in the absence of applied electric field, the gravitational Bond number breaks the pitchfork diagram into two isolated branches of axisymmetric equilibrium solutions. The stable one has a turning point whose location determines the new stability criterion. Quantitative results are presented after solving the resulting set of linear recursive problems by means of the method of lines.

  17. Development of a 3-dimensional design technology for axial pump impellers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Hwan; Kim, Jong In; Park, Jin Seok; Kim, Yong Wan; Kim, Ji Ho [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-03-01

    A design procedure for axial pump impeller was developed based on traditional hydrodynamic theory and experimental correlation. A 3D geometrical modeling procedure of impeller was also developed using I-DEAS program files. In a theoretical design of axial pump impeller, a cascade assumption is used for the velocity triangular diagram. Using this diagram with assumed impeller efficiency, inlet and outlet velocity angles are obtained to determine the shapes of the impeller sections. Total pressure loss through the impeller can be estimated using experimental correlations and the efficiency is obtained from the loss, again. The design procedure continues until the converged efficiency is obtained. The geometrical modeling of the impeller to verify the design result was achieved in I-DEAS CAD software. Program file in I-DEAS was used to model the impeller easily. A FORTRAN code was developed to generate these program files. Therefore complex modeling procedure is simply treated by the generation of the program files and the execution of those in I-DEAS. It was possible to reduce the time required for design and achieve design optimization by applying the developed procedure to the design of SMART MCP. (author). 14 refs., 16 figs.

  18. Elevated temperature axial and torsional fatigue behavior of Haynes 188

    Science.gov (United States)

    Bonacuse, Peter J.; Kalluri, Sreeramesh

    1992-06-01

    The results of high-temperature axial and torsional low-cycle fatigue experiments performed on Haynes 188, a wrought cobalt-base superalloy, are reported. Fatigue tests were performed at 760 C in air on thin-walled tubular specimens at various ranges under strain control. Data are also presented for coefficient of thermal expansion, elastic modulus, and shear modulus at various temperatures from room to 1000 C, and monotonic and cyclic stress-strain curves in tension and in shear at 760 C. The data set is used to evaluate several multiaxial fatigue life models (most were originally developed for room temperature multiaxial life prediction) including von Mises equivalent strain range (ASME boiler and pressure vessel code), Manson-Halford, Modified Multiaxiality Factor (proposed here), Modified Smith-Watson-Topper, and Fatemi-Socie-Kurath. At von Mises equivalent strain ranges (the torsional strain range divided by the square root of 3, taking the Poisson's ratio to be 0.5), torsionally strained specimens lasted, on average, factors of 2 to 3 times longer than axially strained specimens. The Modified Multiaxiality Factor approach shows promise as a useful method of estimating torsional fatigue life from axial fatigue data at high temperatures. Several difficulties arose with the specimen geometry and extensometry used in these experiments. Cracking at extensometer probe indentations was a problem at smaller strain ranges. Also, as the largest axial and torsional strain range fatigue tests neared completion, a small amount of specimen buckling was observed.

  19. Improving axial depth of cut accuracy in micromilling

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2004-01-01

    and their rapid warming and cooling, which prevent the achievement of a steady state. Several other factors, independent on the tool-workpiece interaction, influence the machining accuracy. The cutting parameter most heavily affected is the axial depth of cut which is the most critical when using...

  20. Elevated temperature axial and torsional fatigue behavior of Haynes 188

    Science.gov (United States)

    Bonacuse, Peter J.; Kalluri, Sreeramesh

    1995-01-01

    The results are reported for high-temperature axial and torsional low-cycle fatigue experiments performed at 760 C in air on thin-walled tubular specimens of Haynes 188, a wrought cobalt-based superalloy. Data are also presented for mean coefficient of thermal expansion, elastic modulus, and shear modulus at various temperatures from room to 1000 C, and monotonic and cyclic stress-strain curves in tension and in shear at 760 C. This data set is used to evaluate several multiaxial fatigue life models (most were originally developed for room temperature multiaxial life prediction) including von Mises equivalent strain range (ASME Boiler and Pressure Code), Manson-Halford, modified multiaxiality factor (proposed in this paper), modified Smith-Watson-Topper, and Fatemi-Socie-Kurath. At von Mises equivalent strain ranges (the torsional strain range divided by the square root of 3, taking the Poisson's ratio to be 0.5), torsionally strained specimens lasted, on average, factors of 2 to 3 times longer than axially strained specimens. The modified multiaxiality factor approach shows promise as a useful method of estimating torsional fatigue life from axial fatigue data at high temperatures. Several difficulties arose with the specimen geometry and extensometry used in these experiments. Cracking at extensometer probe indentations was a problem at smaller strain ranges. Also, as the largest axial and torsional strain range fatigue tests neared completion, a small amount of specimen buckling was observed.

  1. Axial heterogeneous core concept applied for super phoenix reactor

    International Nuclear Information System (INIS)

    Always maintaining the current design rules, this paper presents a parametric study on the type of axial heterogeneous core concept (CHA), utilizing a core of fast reactor Super Phenix type, reaching a maximum thermal burnup rate of 150000 M W d/t and being managed in single batch. (author)

  2. Dynamic calibration of tri-axial piezoelectric force transducers

    International Nuclear Information System (INIS)

    Applied dynamic loads are often difficult to measure accurately due to the dynamic response of the sensor used and the dependence of the sensor's sensitivity on the mounting and loading details. For tri-axial force transducers, which are capable of measuring forces along the axial direction and along both directions of the transducer's face, dynamic calibration is further complicated by the coupling of the sensor's measurement directions. For this reason, a new apparatus for dynamic calibration of normal and tangential directions of a tri-axial piezoelectric force transducer has been constructed and tested. The calibration force is provided from a spring loaded uni-axial impulse hammer. The apparatus allows for calibration at a variety of calibration angles and speeds; the loading for all cases of a nonzero calibration angle is oblique, with the point of force application being eccentric to the centerline of the force transducer's normal axis. As such, tangential loads are always accompanied by a normal load. The calibration results show that the normal direction correction factors have a systematic dependence on the calibration angle; the tangential correction factors show some scatter but do not appear to be dependent on the calibration angle

  3. AXIAL DEFFLECTION STUDIES OF RING SHAPED FORCE TRANSDUCER: A REVIEW

    Directory of Open Access Journals (Sweden)

    SUDHIR KUMAR,

    2011-01-01

    Full Text Available The ring shaped force transducers are widely used in practice and are available in varying capacities from few hundred newtons to mega newtons. The present paper discusses the deflection studies of thering shaped force transducers under action of axial forces. Various methods leading to the measurement of deflection have been discussed and compared here.

  4. On the axially symmetric equilibrium of a magnetically confined plasma

    International Nuclear Information System (INIS)

    The axially symmetric equilibrium of a magnetically confined plasma is reconsidered, with the special purpose of studying high-beta schemes with a purely poloidal magnetic field. A number of special solutions of the pressure and magnetic flux functions are shown to exist, the obtained results may form starting-points in a further analysis of physically relevant configurations. (Auth.)

  5. COMPARISON OF AXIAL FAN ROTOR EXPERIMENTAL DATA WITH CFD SIMULATION

    OpenAIRE

    Aleš Prachař

    2016-01-01

    Data obtained from an experimental simulation on a new test rig for axial fans are compared to a CFD simulation. The Edge solver is used and the development needed for the simulation (boundary conditions, free stream consistency) is described. Adequate agreement between the measured and calculated data is observed.

  6. COMPARISON OF AXIAL FAN ROTOR EXPERIMENTAL DATA WITH CFD SIMULATION

    Directory of Open Access Journals (Sweden)

    Aleš Prachař

    2016-02-01

    Full Text Available Data obtained from an experimental simulation on a new test rig for axial fans are compared to a CFD simulation. The Edge solver is used and the development needed for the simulation (boundary conditions, free stream consistency is described. Adequate agreement between the measured and calculated data is observed.

  7. A cylindrical drift chamber with azimuthal and axial position readout

    International Nuclear Information System (INIS)

    A cylindrical multiwire drift chamber with axial charge-division has been constructed and used in experiment E852 at Brookhaven National Laboratory. It serves as a trigger element and as a tracking device for recoil protons in π-p interactions. We describe the chamber's design considerations, details of its construction, electronics, and performance characteristics. (orig.)

  8. Modelling the cardiac transverse-axial tubular system

    Czech Academy of Sciences Publication Activity Database

    Pásek, Michal; Šimurda, J.; Christé, G.; Orchard, C.

    2008-01-01

    Roč. 96, - (2008), s. 226-246. ISSN 0079-6107 Institutional research plan: CEZ:AV0Z20760514 Keywords : cardiac cell * transverse-axial tubular system * quantitative modelling Subject RIV: BO - Biophysics Impact factor: 6.388, year: 2008

  9. On the Applications of Axial Representation of Trigonometric Functions

    Science.gov (United States)

    Siadat, M. Vali

    2006-01-01

    In terms of modern pedagogy, having visual interpretation of trigonometric functions is useful and quite helpful. This paper presents, pictorially, an easy approach to prove all single angle trigonometric identities on the axes. It also discusses the application of axial representation in calculus--finding the derivative of trigonometric functions.

  10. FINITE ELEMENT ANALYSIS OF AXIAL FEED BAR ROLLING

    Institute of Scientific and Technical Information of China (English)

    C.G. Xu; G.H. Liu; G.S. Ren; Z. Shen; C.P. Ma; W. W. Ren

    2007-01-01

    A flexible technique of hot working of bars by axial feed rolling was introduced. The processdeformation, strain field, stress field, and temperature field of the parts are analyzed by finite elementmethod (FEM)-simulation software DEFORM-3D. The material flow rule and tool load have beeninvestigated.

  11. View of the Axial Field Spectrometer (R807)

    CERN Multimedia

    1980-01-01

    In this view of the Axial Field Spectrometer at I8, the vertical uranium/scintillator hadron calorimeter (just left of centre) is retracted to give access to the cylindrical central drift chamber. The yellow iron structure served as a filter to identify muons, with MWPCs and the array of Cherenkov counters to the right.

  12. Axial and focal-plane diffraction catastrophe integrals

    Energy Technology Data Exchange (ETDEWEB)

    Berry, M V [H H Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Howls, C J [School of Mathematics, University of Southampton, Southampton, SO17 1BJ (United Kingdom)

    2010-09-17

    Exact expressions in terms of Bessel functions are found for some of the diffraction catastrophe integrals that decorate caustics in optics and mechanics. These are the axial and focal-plane sections of the elliptic and hyperbolic umbilic diffraction catastrophes, and symmetric elliptic and hyperbolic unfoldings of the X{sub 9} diffraction catastrophes. These representations reveal unexpected relations between the integrals.

  13. On the generation techniques of axially symmetric stationary metrics

    Indian Academy of Sciences (India)

    S Chaudhuri

    2002-03-01

    In the present paper, a relationship between the method of Gutsunaev–Manko and the soliton technique (for two-soliton solutions) of Belinskii–Zakharov, for generating solutions of axially symmetric stationary space-times in general relativity is discussed.

  14. Axial SPN and radial MOC coupled whole core transport calculation

    International Nuclear Information System (INIS)

    The Simplified PN(SPN) method is applied to the axial solution of the two-dimensional (2-D) method of characteristics (MOC) solution based whole core transport calculation. A sub-plane scheme and the nodal expansion method (NEM) are employed for the solution of the one-dimensional (1-D) SPN equations involving a radial transverse leakage. The SPN solver replaces the axial diffusion solver of the DeCART direct whole core transport code to provide more accurate, transport theory based axial solutions. In the sub-plane scheme, the radial equivalent homogenization parameters generated by the local MOC for a thick plane are assigned to the multiple finer planes in the subsequent global three-dimensional (3-D) coarse mesh finite difference (CMFD) calculation in which the NEM is employed for the axial solution. The sub-plane scheme induces a much less nodal error while having little impact on the axial leakage representation of the radial MOC calculation. The performance of the sub-plane scheme and SPN nodal transport solver is examined by solving a set of demonstrative problems and the C5G7MOX 3-D extension benchmark problems. It is shown in the demonstrative problems that the nodal error reaching upto 1,400 pcm in a rodded case is reduced to 10 pcm by introducing 10 sub-planes per MOC plane and the transport error is reduced from about 150 pcm to 10 pcm by using SP3. Also it is observed, in the C5G7MOX rodded configuration B problem, that the eigenvalues and pin power errors of 180 pcm and 2.2% of the 10 sub-planes diffusion case are reduced to 40 pcm and 1.4%, respectively, for SP3 with only about a 15% increase in the computing time. It is shown that the SP5 case gives very similar results to the SP3 case. (author)

  15. Two-dimensional nonlinear dynamics of an axially moving viscoelastic beam with time-dependent axial speed

    International Nuclear Information System (INIS)

    In the present study, the coupled nonlinear dynamics of an axially moving viscoelastic beam with time-dependent axial speed is investigated employing a numerical technique. The equations of motion for both the transverse and longitudinal motions are obtained using Newton’s second law of motion and the constitutive relations. A two-parameter rheological model of the Kelvin–Voigt energy dissipation mechanism is employed in the modelling of the viscoelastic beam material, in which the material time derivative is used in the viscoelastic constitutive relation. The Galerkin method is then applied to the coupled nonlinear equations, which are in the form of partial differential equations, resulting in a set of nonlinear ordinary differential equations (ODEs) with time-dependent coefficients due to the axial acceleration. A change of variables is then introduced to this set of ODEs to transform them into a set of first-order ordinary differential equations. A variable step-size modified Rosenbrock method is used to conduct direct time integration upon this new set of first-order nonlinear ODEs. The mean axial speed and the amplitude of the speed variations, which are taken as bifurcation parameters, are varied, resulting in the bifurcation diagrams of Poincaré maps of the system. The dynamical characteristics of the system are examined more precisely via plotting time histories, phase-plane portraits, Poincaré sections, and fast Fourier transforms (FFTs)

  16. Numerical analysis of an axial-flow pump with different bell mouths

    International Nuclear Information System (INIS)

    Based on the FVM (Finite Volume Method), standard turbulent model used to close the RANS (Reynolds Average Navier- Stokes Equations) equations and scalable wall function, was adopted to treat the flow near wall, and the flow pattern in the bell mouth of a certain axial-flow pump was simulated. The results show that there were some vortexes and spiral flows in the bell mouth if we used a traditional bell mouth which was also used in mixed-flow pump. By optimizing the structure of the bell mouth, the simulated results showed that the flow pattern in the bell mouth was better than a traditional bell mouth, there were no vortexes or spiral flows in the bell mouth, and the performance of the pump was also better than before. Based on the numerical simulation, the new structure of the bell mouth was proposed to be used practical engineering

  17. Powder metallurgy for the fabrication of bi-axially textured Ni tapes for YBCO coated conductors

    International Nuclear Information System (INIS)

    Bi-axially textured Ni tapes for YBCO coated conductors were fabricated by forming, sintering, cold rolling and heat treatment of Ni powder compacts. The powder metallurgy process consists of filling of fine Ni powders in a rubber mold, cold isostatical pressing in a water chamber and sintering of the powder compacts. The sintered compacts were cold-rolled and made into tapes with a thickness of 100 micron and then heat-treated at 1000 deg. C for various time periods for the development of the (2 0 0) texture. The (2 0 0) texture of Ni tape was successfully formed through the optimization of the recrystallization heat treatment condition for the cold rolled Ni tapes. The full width half maximum of the Ni tapes was 8-10 deg. and the atomic force microscopy surface roughness was 3-5 nm

  18. Novel axially carborane-cage substituted silicon phthalocyanine photosensitizer; synthesis, characterization and photophysicochemical properties

    Science.gov (United States)

    Atmaca, Göknur Yaşa; Dizman, Cemil; Eren, Tarık; Erdoğmuş, Ali

    2015-02-01

    The novel axially dicarborane substituted silicon (IV) (SiPc-DC) phthalocyanine was synthesized by treating silicon phthalocyanine dichloride SiPc(Cl)2 (SiPc) with o-Carborane monool. The compound was characterized by mass spectrometry, UV-Vis, FT-IR, 1H and 11B Nuclear Magnetic Resonance Spectroscopy (NMR). Spectral, photophysical (fluorescence quantum yield) and photochemical (singlet oxygen (ΦΔ) and photodegradation quantum yield (Φd)) properties of the complex were reported in different solutions (Dimethyl sulfoxide (DMSO), Dimethylformamide (DMF) and Toluene). The results of spectral measurements showed that both SiPc and carborane cage can have potential to be used as sensitizers in photodynamic therapy (PDT) and boron neutron capture therapy (BNCT) by their singlet oxygen efficiencies (ΦΔ = 0.41, 0.39).

  19. Novel axially carborane-cage substituted silicon phthalocyanine photosensitizer; synthesis, characterization and photophysicochemical properties.

    Science.gov (United States)

    Atmaca, Göknur Yaşa; Dizman, Cemil; Eren, Tarık; Erdoğmuş, Ali

    2015-02-25

    The novel axially dicarborane substituted silicon (IV) (SiPc-DC) phthalocyanine was synthesized by treating silicon phthalocyanine dichloride SiPc(Cl)2 (SiPc) with o-Carborane monool. The compound was characterized by mass spectrometry, UV-Vis, FT-IR, (1)H and (11)B Nuclear Magnetic Resonance Spectroscopy (NMR). Spectral, photophysical (fluorescence quantum yield) and photochemical (singlet oxygen (ΦΔ) and photodegradation quantum yield (Φd)) properties of the complex were reported in different solutions (Dimethyl sulfoxide (DMSO), Dimethylformamide (DMF) and Toluene). The results of spectral measurements showed that both SiPc and carborane cage can have potential to be used as sensitizers in photodynamic therapy (PDT) and boron neutron capture therapy (BNCT) by their singlet oxygen efficiencies (ΦΔ=0.41, 0.39). PMID:25222320

  20. Treating Influenza (Flu)

    Science.gov (United States)

    ... can be used to treat influenza illness. Antiviral drugs fight influenza viruses in your body. They are different from ... chills and fatigue. Your doctor may prescribe antiviral drugs to treat your flu illness. Should Istill get aflu vaccine? Yes. Antiviral ...

  1. How Is Pneumonia Treated?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Is Pneumonia Treated? Treatment for pneumonia depends on the type ... can go back to their normal routines. Bacterial Pneumonia Bacterial pneumonia is treated with medicines called antibiotics. ...

  2. Investigation of Valve Plate in Water Hydraulic Axial Piston Motor

    Institute of Scientific and Technical Information of China (English)

    聂松林; 李壮云; 等

    2002-01-01

    This paper has introduced the developments of water hydraulic axial piston equipments.According to the effects of physicochemical properties of water on water hydraulic components,a novel valve plate for water hydraulic axial motor has been put forward,whose moment exerted by the fluid field between valve plate and bearing plate is balanced entirely.The material screening experiment of valve plate is done on the test rig.Through numerical simulation the effects of some geometry parameters on the performance of water hydraulic motor have been studied.The silencing grooves on the valve plate in water hydraulic motor can reduce the pressure shock and the occurrence of cavitation effectively.It is evident that the appropriate structure should change the wear status between matching paris and reduces the wear and specific pressure of the matching pairs.The specimen with the new type valve plate is used in a tool system.

  3. Developing axial flow cyclone separators for nuclear gas cleaning

    International Nuclear Information System (INIS)

    The principle of the cyclone separator is the separation of particles from a gas stream by causing them to take different routes from the gas stream by virtue of their inertia. In the cyclone system described here, the basic flow is axial, and gas entering the vortex tube is forced into a spiral flow by the fixed blades of the vortex generator. The particulate is thrown outwards to the periphery of the vortex tube by centrifugal force, and is carried away through the annular gap between the vortex tube and outlet tube with a small proportion of the gas flow (ie the scavenge flow). The bulk of the gas flow, from which the particulate has been separated, passes axially down the centre of the outlet tube. The separated contaminant is concentrated into the scavenge gas flow which is piped away for discharge, further concentration or filtration, depending upon system requirements. There are no moving parts. (author)

  4. Instability of meridional axial system in f(R) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, M.; Yousaf, Z. [University of the Punjab, Department of Mathematics, Lahore (Pakistan)

    2015-05-15

    We analyze the dynamical instability of a non-static reflection axial stellar structure by taking into account the generalized Euler equation in metric f(R) gravity. Such an equation is obtained by contracting the Bianchi identities of the usual anisotropic and effective stress-energy tensors, which after using a radial perturbation technique gives a modified collapse equation. In the realm of the R + εR{sup n} gravity model, we investigate instability constraints at Newtonian and post-Newtonian approximations. We find that the instability of a meridional axial self-gravitating system depends upon the static profile of the structure coefficients, while f(R) extra curvature terms induce the stability of the evolving celestial body. (orig.)

  5. Chiral structure of vector and axial-vector tetraquark currents

    International Nuclear Information System (INIS)

    We investigate the chiral structure of local vector and axial-vector tetraquark currents, and study their chiral transformation properties. We consider the charge-conjugation parity and classify all the isovector vector and axial-vector local tetraquark currents of quantum numbers IG JPC =1-1-+, IG JPC =1+1--, IG JPC = 1-1++ and IG JPC = 1+1+-. We find that there is a one to one correspondence among them. Using these currents, we perform QCD sum rule analyses. Our results suggest that there is a missing b1 state having IG JPC =1+1+- and a mass around 1.47-1.66 GeV. (orig.)

  6. Axial positrons emission tomography: from mouse to human brain imaging

    International Nuclear Information System (INIS)

    Positrons emission tomography is a nuclear imaging technics using nuclear decays. It is used both in clinical and preclinical studies. The later requires the use of small animals such as the mouse. The objective is to obtain the best signal with the best spatial resolution. Yet, a weight ratio between humans and mice indicates the need of a sub-millimeter resolution. A conventional scanner is based on detection modules surrounding the object to image and arranged perpendicularly. This implies a strong relationship between efficiency and spatial resolution. This work focuses on the axial geometry in which detection modules are arranged parallel to the object. This limits the relationship between the figures of merit, leading to both high spatial resolution and efficiency. The simulations of prototypes showed great perspectives in term of sub-millimeter resolution with efficiencies of 15 or 40% according to the scanner's axial extension. These results indicate great perspectives for both clinical and preclinical imaging. (author)

  7. Ultraviolet and infrared aspects of the axial anomaly. I

    International Nuclear Information System (INIS)

    The paper is the first part of a brief review of some perturbative aspects of the Adler-Bell-Jackiw axial anomaly, described in terms of ultraviolet and infrared behavior of the famous VVA triangle graph. Apart from a general overview of the diversified role played by the anomaly in quantum field theory and particle physics, an elementary introduction is presented to the subject of the anomaly, comprehensible to an uninitiated reader with only a basic background in quantum field theory. The ultraviolet aspects of the anomaly are stressed and the topics covered are the following: vector and axial-vector Ward identities for the VVA triangle graph; the anomaly and several ways to derive it, namely the symmetric momentum cut-off and shifting the integration variables in linearly divergent integrals; the Adler-Rosenberg argument; the Pauli-Villars method; and dimensional regularization. (author) 2 figs., 34 refs

  8. Regularized path integrals and anomalies -- U(1) axial gauge theory

    CERN Document Server

    Kopper, Christoph

    2011-01-01

    We analyse the origin of the Adler anomaly of axial U(1) gauge theory within the framework of regularized path integrals. Momentum or position space regulators allow for mathematically well-defined path integrals but violate local gauge symmetry. It is known how (nonanomalous) gauge symmetry can be recovered in the renormalized theory in this case [1]. Here we analyse U(1) axial gauge theory to show how the appearance of anomalies manifests itself in such a context. We show that the three-photon amplitude leads to a violation of the Slavnov-Taylor-Identities which cannot be restored on taking the UV limit in the renormalized theory. We point out that this fact is related to the nonanalyticity of this amplitude in the infrared region.

  9. Chiral symmetry restoration and axial vector renormalization for Wilson fermions

    CERN Document Server

    Reisz, T

    2000-01-01

    Lattice gauge theories with Wilson fermions break chiral symmetry. In theU(1) axial vector current this manifests itself in the anomaly. On the otherhand it is generally expected that the axial vector flavour mixing current isnon-anomalous. We give a short, but strict proof of this to all orders ofperturbation theory, and show that chiral symmetry restauration implies aunique multiplicative renormalization constant for the current. This constantis determined entirely from an irrelevant operator in the Ward identity. Thebasic ingredients going into the proof are the lattice Ward identity, chargeconjugation symmetry and the power counting theorem. We compute therenormalization constant to one loop order. It is largely independent of theparticular lattice realization of the current.

  10. Computerized axial tomography : the tool in osseointegrated dental implants

    International Nuclear Information System (INIS)

    Failure rates in rehabilitations with osseointegrated implants are handled through appropriate radiographic preoperative planning. The appropriate length of the implant without running the risk of a perforation of vital structures, has been determined by a radiographic diagnosis. Computerized and conventional axial tomography have proved to be invaluable elements for pre-surgical evaluation. A radiologic guidance is elaborated to perform a computerized axial tomography (CT) of maxillary bones in totally edentulous patients. Surgical guides are constructed from a wax-up emanated from the information of the CT. The CT has proven to be an radiographic indispensable element to achieve the surgical-prosthetic success in osseointegrated dental implants. The CT has allowed the realization of a precise wax-up for making of surgical guide and a precise temporary prostheses in positioning of osseointegrated implants, with the consequent saving time and money for the rehabilitator and patient

  11. Fully Characterizing Axially Symmetric Szekeres Models With Three Data Sets

    CERN Document Server

    Célérier, Marie-Noëlle; Singh, Tejinder P

    2012-01-01

    Inhomogeneous exact solutions of General Relativity with zero cosmological constant have been used in the literature to challenge the \\Lambda CDM model. From one patch Lema\\^itre-Tolman-Bondi (LTB) models to axially symmetric quasi-spherical Szekeres (QSS) Swiss-cheese models, some of them are able to reproduce to a good accuracy the cosmological data. It has been shown in the literature that a zero-\\Lambda -LTB model with a central observer can be fully determined by two data sets. We demonstrate that an axially symmetric zero-\\Lambda -QSS model with an observer located at the origin can be fully reconstructed from three data sets, number counts, luminosity distance and redshift drift. This is a first step towards a future demonstration involving five data sets and the most general Szekeres model.

  12. Buckling Imperfection Sensitivity of Axially Compressed Orthotropic Cylinders

    Science.gov (United States)

    Schultz, Marc R.; Nemeth, Michael P.

    2010-01-01

    Structural stability is a major consideration in the design of lightweight shell structures. However, the theoretical predictions of geometrically perfect structures often considerably over predict the buckling loads of inherently imperfect real structures. It is reasonably well understood how the shell geometry affects the imperfection sensitivity of axially compressed cylindrical shells; however, the effects of shell anisotropy on the imperfection sensitivity is less well understood. In the present paper, the development of an analytical model for assessing the imperfection sensitivity of axially compressed orthotropic cylinders is discussed. Results from the analytical model for four shell designs are compared with those from a general-purpose finite-element code, and good qualitative agreement is found. Reasons for discrepancies are discussed, and potential design implications of this line of research are discussed.

  13. The anomalous transport of axial charge: topological vs non-topological fluctuations

    CERN Document Server

    Iatrakis, Ioannis; Yin, Yi

    2015-01-01

    Axial charge imbalance is an essential ingredient in novel effects associated with chiral anomaly such as chiral magnetic effects (CME). In a non-Abelian plasma with chiral fermions, local axial charge can be generated a) by topological fluctuations which would create domains with non-zero winding number b) by conventional non-topological thermal fluctuations. We provide a holographic evaluations of medium's response to dynamically generated axial charge density in hydrodynamic limit and examine if medium's response depends on the microscopic origins of axial charge imbalance. We show a local domain with non-zero winding number would induce a non-dissipative axial current due to chiral anomaly. We illustrate holographically that a local axial charge imbalance would be damped out with the damping rate related to Chern-Simon diffusive constant. By computing chiral magnetic current in the presence of dynamically generated axial charge density, we found that the ratio of CME current over the axial charge density ...

  14. Self-consistent calculation for the transport of intense pulsed beams in axial-symmetrical electrostatic fields

    CERN Document Server

    Li Chao Long; Lu Jian Qin

    2003-01-01

    A program for calculating intense pulsed beams transport in axial-symmetrical electrostatic fields is designed. The program can calculate beam optical systems consisting of the following elements: drift spaces, three-cylinder einzel lenses, three-diaphragm einzel lenses, electrostatic accelerating tubes, as well as two-cylinder lenses. In the calculations, the effective fields of each lens are divided into several small intervals, and each interval is treated as a uniform accelerating field, each dividing point is considered as a thin lens, and iterations are used to get self-consistent solutions. Iteration procedures are incorporated in the codes to get self-consistent solutions

  15. Synthesis and Spectroscopic Characterization of Some New Axially Ligated Indium(III Macrocyclic Complexes and Their Biological Activities

    Directory of Open Access Journals (Sweden)

    Gauri D. Bajju

    2014-01-01

    Full Text Available The synthesis and spectroscopic characterization of new axially ligated indium(III porphyrin complexes were reported. Chloroindium(III porphyrin (TPPIn-Cl was obtained in good yield by treating the corresponding free base with indium trichloride. The action of the different phenols on chloroderivatives (TPPIn-Cl led to the corresponding phenolato complexes (TPPIn-X. These derivatives were characterized on the basis of mass spectrometry, 1H-NMR, IR, and UV-visible data. The separation and isolation of these derivatives have been achieved through chromatography. The spectral properties of free base porphyrin and its corresponding metallated and axially ligated indium(III porphyrin compounds were compared with each other. A detailed analysis of UV-Vis, 1H-NMR, and IR suggested the transformation from free base porphyrin to indium(III porphyrin. Besides, 13C-NMR and fluorescence spectra were also reported and interpreted. The stability of these derivatives has also been studied through thermogravimetry. The complexes were also screened for anticancerous activities. Among all the complexes, 4-MePhO-InTPP shows highest anticancerous activity. The title complexe, TPPIn-X (where X = different phenolates, represents a five-coordinate indium(III porphyrin complex in a square-pyramidal geometry with the phenolate anion as the axial ligand.

  16. Dynamics and statics of flexible axially symmetric shallow shells

    OpenAIRE

    Awrejcewicz, J.; Krysko, V. A.; I. V. Kravtsova

    2006-01-01

    In this work, we propose the method for the investigation of stochastic vibrations of deterministic mechanical systems represented by axially symmetric spherical shells. These structure members are widely used as sensitive elements of pressure measuring devices in various branches of measuring and control industry, machine design, and so forth. The proposed method can be easily extended for the investigation of shallow spherical shells, goffer-type membranes, and so on. T...

  17. Axial Compressor Stall and Surge Prediction by Measurements

    OpenAIRE

    Hönen, H.

    1999-01-01

    The paper deals with experimental investigations and analyses of unsteady pressure distributions in different axial compressors. Based on measurements in a single stage research compressor the influence of increasing aerodynamic load onto the pressure and velocity fluctuations is demonstrated. Detailed measurements in a 14-stage and a 17-stage gas turbine compressor are reported. For both compressors parameters could be found which are clearly influenced by the aerodynamic load.For the 14-sta...

  18. Numerical Study of Multistage Transcritical Organic Rankine Cycle Axial Turbines

    OpenAIRE

    SCIACOVELLI, L.; CINNELLA, Paola

    2014-01-01

    Transonic flows through axial, multi-stage, transcritical ORC turbines, are investigated by using a numerical solver including advanced multiparameter equations of state and a high-order discretization scheme. The working fluids in use are the refrigerants R134a and R245fa, classified as dense gases due to their complex molecules and relatively high molecular weight. Both inviscid and viscous numerical simulations are carried out to quantify the impact of dense gas effects and viscous effe...

  19. Exact Axially Symmetric Solution in f(T) Gravity Theory

    OpenAIRE

    2014-01-01

    A general tetrad field with sixteen unknown functions is applied to the field equations of f(T) gravity theory. An analytic vacuum solution is derived with two constants of integration and an angle Φ that depends on the angle coordinate ϕ and radial coordinate r . The tetrad field of this solution is axially symmetric and the scalar torsion vanishes. We calculate the associated metric of the derived solution and show that it represents Kerr spacetime. Finally, we show that the derived solutio...

  20. Wilson Loop and the Treatment of Axial Gauge Poles

    OpenAIRE

    Joglekar, Satish D.; Misra, A.

    1999-01-01

    We consider the question of gauge invariance of the Wilson loop in the light of a new treatment of axial gauge propagator proposed recently based on a finite field-dependent BRS (FFBRS) transformation. We remark that as under the FFBRS transformation the vacuum expectation value of a gauge invariant observable remains unchanged, our prescription automatically satisfies the Wilson loop criterion. Further, we give an argument for {\\it direct} verification of the invariance of Wilson loop to O(g...

  1. Axial field permanent magnet DC motor with powder iron armature

    OpenAIRE

    Sharkh, Suleiman M.A.; Mohammad, Mohammad T.

    2007-01-01

    The paper describes a double-gap axial field permanent magnet (PM) dc motor whose double-layer armature wave winding is constructed of copper strips. It investigates the performance of two machines using powder iron and lamination steel materials as armature teeth. Tests are conducted to evaluate the motor torque and speed curves as well as their efficiency under different loads. Finite element analysis (FEA) and equivalent circuit models are used to determine the levels of the magnetic satur...

  2. Gas liquid separation within a novel axial flow cyclone separator

    OpenAIRE

    Dickson, Philip James

    1998-01-01

    Cyclone separators have been described in detail and, although substantial research has been performed on solid / gas devices, the use of cyclones for gas / liquid separation has been comparatively ignored; this is particularly true for higher concentrations of liquid and for degassing applications. Consequently no generic models are available which will predict separation efficiency or pressure drop for all designs of cyclone. A novel design of axial flow cyclone called WELLSE...

  3. Vacuum arc under axial magnetic fields: experimental and simulation research

    International Nuclear Information System (INIS)

    Axial magnetic field (AMF) technology is a most important control method of vacuum arc, particularly for high-current vacuum arcs in vacuum interrupters. In this paper, a review of the state of current research on vacuum arcs under AMF is presented. The major aspects of vacuum arc in an AMF such as arc voltage, the motion of cathode spots, and anode activities are discussed, and the most recent progress both of experimental and simulation research is presented. (topical review)

  4. Crushing modes of aluminium tubes under axial compression

    OpenAIRE

    Pled, Florent; Yan, Wenyi; Wen, Cui'e

    2014-01-01

    6 pages International audience A numerical study of the crushing of circular aluminium tubes with and without aluminium foam fillers has been carried out to investigate their buckling behaviours under axial compression. A crushing mode classification chart has been established for empty tubes. The influence of boundary conditions on crushing mode has also been investigated. The effect of foam filler on the crushing mode of tubes filled with foam was then examined. The predicted results ...

  5. Overview of the Axial Field Spectrometer in the ISR tunnel

    CERN Multimedia

    1980-01-01

    A view of the Axial Field Spectrometer – the last large experiment at the ISR. The horizontal top and vertical outer arrays of the uranium-scintillator hadron calorimeter are clear to be seen, with the blue cylindrical pole piece of the magnet just visible. The pipes that are visible in front of the pole piece are cryogenic feed pipes for the superconducting low-beta quadrupoles.

  6. Axial form factor of the nucleon at large momentum transfers

    CERN Document Server

    Anikin, I V; Offen, N

    2016-01-01

    Motivated by the emerging possibilities to study threshold pion electroproduction at large momentum transfers at Jefferson Laboratory following the 12 GeV upgrade, we provide a short theory summary and an estimate of the nucleon axial form factor for large virtualities in the $Q^2 = 1-10~\\text{GeV}^2$ range using next-to-leading order light-cone sum rules.

  7. Modelling of the axial-flow gas laser

    International Nuclear Information System (INIS)

    A mathematical model is advanced for the axial-flow gas laser under the premise that the flow in the cylindrical tube occurs at both small Reynolds number and magnetic Reynolds number, in the presence of free convection heat transfer. Hence the induced magnetic fields may be neglected and perturbation methods are adopted to construct analytical solutions. These solutions are discussed quantitatively. (author). 4 refs, 2 figs

  8. Axial Anomaly and Index of the Overlap Hypercube Operator

    OpenAIRE

    Adams, David H.; Bietenholz, Wolfgang

    2003-01-01

    The overlap hypercube fermion is constructed by inserting a lattice fermion with hypercubic couplings into the overlap formula. One obtains an exact Ginsparg-Wilson fermion, which is more complicated than the standard overlap fermion, but which has improved practical properties and is of current interest for use in numerical simulations. Here we deal with conceptual aspects of the overlap hypercube Dirac operator. Specifically, we evaluate the axial anomaly and the index, demonstrating that t...

  9. Cylindrical Cloak with Axial Permittivity/Permeability Spatially Invariant

    OpenAIRE

    Luo, Yu; Zhang, Jingjing; Chen, Hongsheng; Xi, Sheng; Wu, Bae-Ian

    2008-01-01

    In order to reduce the difficulties in the experimental realizations of the cloak but still keep good performance of invisibility, we proposed a perfect cylindrical invisibility cloak with spatially invariant axial material parameters. The advantage of this kind of TE (or TM) cloak is that only rho and phi components of mu (or epsilon) are spatially variant, which makes it possible to realize perfect invisibility with two-dimensional (2D) magnetic (or electric) metamaterials. The effects of p...

  10. Identification of material parameters using bi-axial machine

    OpenAIRE

    Flores, Paulo; de Montleau, P.; Mathonet, V.; Moureaux, P. (collab.); Habraken, Anne

    2004-01-01

    Experimental testing equipment is built in order to identify material parameters of complex phenomenological constitutive laws. This equipment consists in a bi-axial test machine able to perform plane strain and simple shear tests separately or simultaneously and a Miyauchi simple shear test device; an optical extensometer is used to identify the strain field. The article focus on the validation of the results of this new equipment by comparing with results obtained by standard machines and/o...

  11. The Electroweak Standard Model in the Axial Gauge

    CERN Document Server

    Dams, C; Dams, Chris; Kleiss, Ronald

    2004-01-01

    We derive the Feynman rules of the standard model in the axial gauge. After this we prove that the fields $\\phi_W$ and $\\phi_Z$ do not correspond to physical particles. As a consequence, these fields cannot appear as incoming or outgoing lines in Feynman graphs. We then calculate the contribution of these fields in the case of a particular decay mode of the top quark.

  12. Killing tensors in stationary and axially symmetric space-times

    CERN Document Server

    Vollmer, Andreas

    2016-01-01

    We discuss the existence of Killing tensors for certain (physically motivated) stationary and axially symmetric vacuum space-times. We show nonexistence of a nontrivial Killing tensor for a Tomimatsu-Sato metric (up to valence 7), for a C-metric (up to valence 9) and for a Zipoy-Voorhees metric (up to valence 11). The results are obtained by mathematically completely rigorous, nontrivial computer algebra computations with a huge number of equations involved in the problem.

  13. CFD analysis on the blades of an axial gas turbine

    OpenAIRE

    García Unzue, Javier

    2011-01-01

    This project analyzes two-dimensional linear cascade flows of an axial compressor on the stator vanes. It analyzes the influence of the angle of attack in the leading edge for different pressure ratios. The problem studied is a compressible, viscous and steady flow. A test case of an inviscid model flow has been carried out as well. Two types of grid are also being analyzed, the unstructured grid, with only triangular mesh elements, and a structured grid with only quadrilateral...

  14. Axial anomaly, Dirac sea, and the chiral magnetic effect

    OpenAIRE

    Kharzeev, Dmitri E.

    2010-01-01

    Gribov viewed the axial anomaly as a manifestation of the collective motion of charged fermions with arbitrarily high momenta in the vacuum. In the presence of an external magnetic field and a chirality imbalance, this collective motion becomes directly observable in the form of the electric current - this is the chiral magnetic effect (CME). I give an elementary introduction into the physics of CME, and discuss some recent developments.

  15. Improvement of the axial buckling capability of elliptical cylindrical shells

    OpenAIRE

    Paschero, Maurizio

    2008-01-01

    A rather thorough and novel buckling analysis of an axially-loaded orthotropic circular cylindrical shell is formulated. The analysis assumes prebuckling rotations are negligible and uses a unique re-defining of the orthotropic material properties in terms of a so-called geometric mean isotropic (GMI) material. Closed-form expressions for the buckling stress in terms of cylinder geometry and orthotropic material properties are presented, the particular closed form depending on ...

  16. Evaluation of Satisfaction and Axial Rigidity with Titan XL Cylinders

    OpenAIRE

    Gerard D. Henry; Caroline Jennermann; J. Francois Eid

    2012-01-01

    The inflatable penile prosthesis (IPP) has high patient satisfaction rates and good mechanical reliability rates in multiple studies. The number one patient compliant at six months is penile length. Recently, new technique for aggressive sizing of the cylinders has been published on in the literature. One IPP company has produced a new product that has longer length cylinders (XL) than those available. However, traditionally long cylinders were felt to lack axial rigidity. Therefore, a prospe...

  17. On burr height estimation based on axial drilling force

    OpenAIRE

    A. Sokołowski

    2010-01-01

    Purpose: The main goal of the research is to build a model of relationship between burr height created during drilling operation and signal representing axial drilling force. Such a model can be applied in diagnostic system for on-line estimation of bur height.Design/methodology/approach: The first applied approach is based on a step by step procedure in which several statistical models were built. The second one is based on specific features of artificial intelligence methods. The artificial...

  18. Axial and Centrifugal Compressor Mean Line Flow Analysis Method

    Science.gov (United States)

    Veres, Joseph P.

    2009-01-01

    This paper describes a method to estimate key aerodynamic parameters of single and multistage axial and centrifugal compressors. This mean-line compressor code COMDES provides the capability of sizing single and multistage compressors quickly during the conceptual design process. Based on the compressible fluid flow equations and the Euler equation, the code can estimate rotor inlet and exit blade angles when run in the design mode. The design point rotor efficiency and stator losses are inputs to the code, and are modeled at off design. When run in the off-design analysis mode, it can be used to generate performance maps based on simple models for losses due to rotor incidence and inlet guide vane reset angle. The code can provide an improved understanding of basic aerodynamic parameters such as diffusion factor, loading levels and incidence, when matching multistage compressor blade rows at design and at part-speed operation. Rotor loading levels and relative velocity ratio are correlated to the onset of compressor surge. NASA Stage 37 and the three-stage NASA 74-A axial compressors were analyzed and the results compared to test data. The code has been used to generate the performance map for the NASA 76-B three-stage axial compressor featuring variable geometry. The compressor stages were aerodynamically matched at off-design speeds by adjusting the variable inlet guide vane and variable stator geometry angles to control the rotor diffusion factor and incidence angles.

  19. Can the nucleon axial charge be O(Nc^0)?

    CERN Document Server

    Kojo, Toru

    2012-01-01

    The nucleon self-energy and its relation to the nucleon axial charge gA are discussed at large Nc. The energy is compared for the hedgehog, conventional, and recently proposed dichotomous nucleon wavefunctions which give different values for gA. We consider their energies at both perturbative and non-perturbative levels. In perturbative estimates, we take into account the pion exchanges among quarks up to the third orders of axial charge vertices, including the many-body forces such as the Wess-Zumino terms. It turns out that the perturbative pion exchanges among valence quarks give the same leading Nc contributions for three wavefunctions, while their mass differences are O(Lamba_qcd). The signs of splittings flip for different orders of the axial charge vertices, so it is hard to conclude which one is the most energetically favored. For non-perturbative estimates involving the modification of quark bases, we use the chiral quark soliton model as an illustration. With the hedgehog quark wavefunctions with gA...

  20. Bounding axial profile analysis for the topical report database

    International Nuclear Information System (INIS)

    Quantifying the open-quotes end effectsclose quotes reactivities of realistic end-of-cycle burnup distributions is important in performing criticality safety analyses for spent fuel shipping containers. Yankee Atomic Electric Company has compiled an axial burnup profile database (ABPD) for a large number of PWR fuel types. The profiles for fuel types with initially uniform axial loadings of U-235 and burnable poisons were collected from the ABPD to form the topical report database (TRD). Based on the TRD, a strategy was set up to find bounding profiles which conservatively estimate the maximum open-quotes end effectsclose quotes reactivities in different burnup ranges. A two-group, one-dimensional diffusion code, REALAX, was used to calculate the k-effectives and open-quotes end effectsclose quotes reactivities for each of the axially varying burnup distributions in the TRD. REALAX was also proven to have consistency with the well-known three-dimensional, multi-group diffusion code, DIF3D

  1. The new performance calculation method of fouled axial flow compressor.

    Science.gov (United States)

    Yang, Huadong; Xu, Hong

    2014-01-01

    Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section includes the first 50% stages which reflect the fouling level, and the second section includes the last 50% stages which are viewed as the clean stage because of less deposits. In this model, the performance of the first section is obtained by combining scaling law method and linear progression model with traditional stage stacking method; simultaneously ambient conditions and engine configurations are considered. On the other hand, the performance of the second section is calculated by averaged infinitesimal stage method which is based on Reynolds' law of similarity. Finally, the model is successfully applied to predict the 8-stage axial flow compressor and 16-stage LM2500-30 compressor. The change of thermodynamic parameters such as pressure ratio, efficiency with the operating time, and stage number is analyzed in detail. PMID:25197717

  2. The New Performance Calculation Method of Fouled Axial Flow Compressor

    Directory of Open Access Journals (Sweden)

    Huadong Yang

    2014-01-01

    Full Text Available Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section includes the first 50% stages which reflect the fouling level, and the second section includes the last 50% stages which are viewed as the clean stage because of less deposits. In this model, the performance of the first section is obtained by combining scaling law method and linear progression model with traditional stage stacking method; simultaneously ambient conditions and engine configurations are considered. On the other hand, the performance of the second section is calculated by averaged infinitesimal stage method which is based on Reynolds’ law of similarity. Finally, the model is successfully applied to predict the 8-stage axial flow compressor and 16-stage LM2500-30 compressor. The change of thermodynamic parameters such as pressure ratio, efficiency with the operating time, and stage number is analyzed in detail.

  3. Fundamental metallurgical aspects of axial splitting in zircaloy cladding

    International Nuclear Information System (INIS)

    Fundamental metallurgical aspects of axial splitting in irradiated Zircaloy cladding have been investigated by microstructural characterization and analytical modeling, with emphasis on application of the results to understand high-burnup fuel failure under RIA situations. Optical microscopy, SEM, and TEM were conducted on BWR and PWR fuel cladding tubes that were irradiated to fluence levels of 3.3 x 1021 n cm-2 to 5.9 x 1021 n cm-2 (E > 1 MeV) and tested in hot cell at 292--325 C in Ar. The morphology, distribution, and habit planes of macroscopic and microscopic hydrides in as-irradiated and posttest cladding were determined by stereo-TEM. The type and magnitude of the residual stress produced in association with oxide-layer growth and dense hydride precipitation, and several synergistic factors that strongly influence axial-splitting behavior were analyzed. The results of the microstructural characterization and stress analyses were then correlated with axial-splitting behavior of high-burnup PWR cladding reported for simulated-RIA conditions. The effects of key test procedures and their implications for the interpretation of RIA test results are discussed

  4. Axial power monitoring uncertainty in the Savannah River Reactors

    International Nuclear Information System (INIS)

    The results of this analysis quantified the uncertainty associated with monitoring the Axial Power Shape (APS) in the Savannah River Reactors. Thermocouples at each assembly flow exit map the radial power distribution and are the primary means of monitoring power in these reactors. The remaining uncertainty in power monitoring is associated with the relative axial power distribution. The APS is monitored by seven sensors that respond to power on each of nine vertical Axial Power Monitor (APM) rods. Computation of the APS uncertainty, for the reactor power limits analysis, started with a large database of APM rod measurements spanning several years of reactor operation. A computer algorithm was used to randomly select a sample of APSs which were input to a code. This code modeled the thermal-hydraulic performance of a single fuel assembly during a design basis Loss-of Coolant Accident. The assembly power limit at Onset of Significant Voiding was computed for each APS. The output was a distribution of expected assembly power limits that was adjusted to account for the biases caused by instrumentation error and by measuring 7 points rather than a continuous APS. Statistical analysis of the final assembly power limit distribution showed that reducing reactor power by approximately 3% was sufficient to account for APS variation. This data confirmed expectations that the assembly exit thermocouples provide all information needed for monitoring core power. The computational analysis results also quantified the contribution to power limits of the various uncertainties such as instrumentation error

  5. Period of vibration of axially vibrating truly nonlinear rod

    Science.gov (United States)

    Cveticanin, L.

    2016-07-01

    In this paper the axial vibration of a muscle whose fibers are parallel to the direction of muscle compression is investigated. The model is a clamped-free rod with a strongly nonlinear elastic property. Axial vibration is described by a nonlinear partial differential equation. A solution of the equation is constructed for special initial conditions by using the method of separation of variables. The partial differential equation is separated into two uncoupled strongly nonlinear second order differential equations. Both equations, with displacement function and with time function are exactly determined. Exact solutions are given in the form of inverse incomplete and inverse complete Beta function. Using boundary and initial conditions, the frequency of vibration is obtained. It has to be mentioned that the determined frequency represents the exact analytic description for the axially vibrating truly nonlinear clamped-free rod. The procedure suggested in this paper is applied for calculation of the frequency of the longissimus dorsi muscle of a cow. The influence of elasticity order and elasticity coefficient on the frequency property is tested.

  6. HTS axial flux induction motor with analytic and FEA modeling

    International Nuclear Information System (INIS)

    Highlights: •A high temperature superconductor axial flux induction motor and a novel maglev scheme are presented. •Analytic method and finite element method have been adopted to model the motor and to calculate the force. •Magnetic field distribution in HTS coil is calculated by analytic method. •An effective method to improve the critical current of HTS coil is presented. •AC losses of HTS coils in the HTS axial flux induction motor are estimated and tested. -- Abstract: This paper presents a high-temperature superconductor (HTS) axial-flux induction motor, which can output levitation force and torque simultaneously. In order to analyze the character of the force, analytic method and finite element method are adopted to model the motor. To make sure the HTS can carry sufficiently large current and work well, the magnetic field distribution in HTS coil is calculated. An effective method to improve the critical current of HTS coil is presented. Then, AC losses in HTS windings in the motor are estimated and tested

  7. On the axial $U(1)$ symmetry at finite temperature

    CERN Document Server

    Cossu, Guido; Hashimoto, Shoji; Noaki, Jun-ichi; Tomiya, Akio

    2015-01-01

    We study the $U(1)_A$ anomaly in two-flavor lattice QCD at finite temperature with the M\\"obius domain-wall Dirac operator. We generate gauge configurations in the temperature range $(0.9, 1.2) T_c$ on different physical volumes, $L=$ 2--4 fm, and lattice spacings. We measure the difference of the susceptibilities of the flavor non-singlet scalar ($\\chi_\\delta$) and pseudoscalar ($\\chi_\\pi$) mesons. They are related by an axial $U(1)$ transformation and the difference vanishes if the axial $U(1)$ symmetry is respected. We identify the source of axial $U(1)$ symmetry breaking at finite temperature in the lowest eigenmodes, for the observable $\\chi_\\pi - \\chi_\\delta$. We then reweight the M\\"obius domain-wall fermion partition function to that of the overlap-Dirac operator to fully recover chiral symmetry. Our data show a significant discrepancy in the results coming from the M\\"obius domain-wall valence quarks, the overlap valence quarks on our DWF configurations and the reweighted ones that have full chiral s...

  8. Behavior of Unbonded Flexible Risers Subject to Axial Tension

    Institute of Scientific and Technical Information of China (English)

    任少飞; 唐文勇; 郭晋挺

    2014-01-01

    Owing to nonlinear contact problems with slip and friction, a lot of limiting assumptions are made when developing analytical models to simulate the behavior of an unbonded flexible riser. Meanwhile, in order to avoid convergence problems and excessive calculating time associated with running the detailed finite element (FE) model of an unbonded flexible riser, interlocked carcass and zeta layers with complicated cross section shapes are replaced by simple geometrical shapes (e.g. hollow cylindrical shell) with equivalent orthotropic materials. But the simplified model does not imply the stresses equivalence of these two layers. To solve these problems, based on ABAQUS/Explicit, a numerical method that is suitable for the detailed FE model is proposed. In consideration of interaction among all component layers, the axial stiffness of an eight-layer unbonded flexible riser subjected to axial tension is predicted. Compared with analytical and experimental results, it is shown that the proposed numerical method not only has high accuracy but also can substantially reduce the calculating time. In addition, the impact of the lay angle of helical tendons on axial stiffness is discussed.

  9. Axial Non-linear Dynamic Soil-Pile Interaction - Keynote

    Directory of Open Access Journals (Sweden)

    Holeyman A.

    2014-01-01

    Full Text Available This keynote lecture describes recent analytical and numerical advances in the modeling of the axial nonlinear dynamic interaction between a single pile and its embedding soil. On one hand, analytical solutions are developed for assessing the nonlinear axial dynamic response of the shaft of a pile subjected to dynamic loads, and in particular to vibratory loads. Radial inhomogeneity arising from shear modulus degradation is evaluated over a range of parameters and compared with those obtained by other authors and by a numerical radial discrete model simulating the pile and soil movements from integration of the laws of motion. New approximate non linear solutions for axial pile shaft behaviour developed from general elastodynamic equations are presented and compared to existing linear solutions. The soil non linear behaviour and its ability to dissipate mechanical energy upon cyclic loading are shown to have a significant influence on the mechanical impedance provided by the surrounding soil against pile shaft movement. The limitations of over-simplified modelling of pile response are highlighted.

  10. HTS axial flux induction motor with analytic and FEA modeling

    Energy Technology Data Exchange (ETDEWEB)

    Li, S., E-mail: alexlee.zn@gmail.com; Fan, Y.; Fang, J.; Qin, W.; Lv, G.; Li, J.H.

    2013-11-15

    Highlights: •A high temperature superconductor axial flux induction motor and a novel maglev scheme are presented. •Analytic method and finite element method have been adopted to model the motor and to calculate the force. •Magnetic field distribution in HTS coil is calculated by analytic method. •An effective method to improve the critical current of HTS coil is presented. •AC losses of HTS coils in the HTS axial flux induction motor are estimated and tested. -- Abstract: This paper presents a high-temperature superconductor (HTS) axial-flux induction motor, which can output levitation force and torque simultaneously. In order to analyze the character of the force, analytic method and finite element method are adopted to model the motor. To make sure the HTS can carry sufficiently large current and work well, the magnetic field distribution in HTS coil is calculated. An effective method to improve the critical current of HTS coil is presented. Then, AC losses in HTS windings in the motor are estimated and tested.

  11. Efficient propulsion structure with an axial flux rotary converter for hev drive unit

    OpenAIRE

    Havel, Aleš; Vaculík, Petr; Slivka, David

    2011-01-01

    This paper describes an efficient axial flux arrangement of the four quadrant rotary converter for hybrid electric vehicles. The design of the axial flux wound stator and both axial flux squirrel cage rotors is based on the arrangement of radial air gap induction motor and permanent magnet synchronous motor. The method of constant magnetic circuit volume is utilized for dimensions conversion, which results into basic dimensions of stator and rotor discs in axial flux conception. This allows t...

  12. Efficient Propulsion Structure with an Axial Flux Rotary Converter for HEV Drive Unit

    OpenAIRE

    Ales Havel; Petr Vaculik; David Slivka

    2011-01-01

    This paper describes an efficient axial flux arrangement of the four quadrant rotary converter for hybrid electric vehicles. The design of the axial flux wound stator and both axial flux squirrel cage rotors is based on the arrangement of radial air gap induction motor and permanent magnet synchronous motor. The method of constant magnetic circuit volume is utilized for dimensions conversion, which results into basic dimensions of stator and rotor discs in axial flux conception. This allows t...

  13. Defining and generating axial lines from street center lines for better understanding of urban morphologies

    OpenAIRE

    Xintao, Liu; Bin, Jiang

    2012-01-01

    Axial lines are defined as the longest visibility lines for representing individual linear spaces in urban environments. The least number of axial lines that cover the free space of an urban environment or the space between buildings constitute what is often called an axial map. This is a fundamental tool in space syntax, a theory developed by Bill Hillier and his colleagues for characterizing the underlying urban morphologies. For a long time, generating axial lines with help of some graphic...

  14. Experimental studies of axial magnetic fields generated in ultrashort-pulse laser-plasma interaction

    Institute of Scientific and Technical Information of China (English)

    李玉同; 张杰; 陈黎明; 赵理曾; 夏江帆; 魏志义; 江文勉

    2000-01-01

    The quasistatic axial magnetic fields in plasmas produced by ultrashort laser pulses were measured by measuring the Faraday rotation angle of the backscattered emission. The spatial distribution of the axial magnetic field was obtained with a peak value as high as 170 Tesla. Theory suggests that the axial magnetic field is generated by dynamo effect in laser-plasma interaction.

  15. Design and axial optimization of nuclear fuel for BWR reactors

    International Nuclear Information System (INIS)

    In the present thesis, the modifications made to the axial optimization system based on Tabu Search (BT) for the axial design of BWR fuel type are presented, developed previously in the Nuclear Engineering Group of the UNAM Engineering Faculty. With the modifications what is mainly looked is to consider the particular characteristics of the mechanical design of the GE12 fuel type, used at the moment in the Laguna Verde Nucleo electric Central (CNLV) and that it considers the fuel bars of partial longitude. The information obtained in this thesis will allow to plan nuclear fuel reloads with the best conditions to operate in a certain cycle guaranteeing a better yield and use in the fuel burnt, additionally people in charge in the reload planning will be favored with the changes carried out to the system for the design and axial optimization of nuclear fuel, which facilitate their handling and it reduces their execution time. This thesis this developed in five chapters that are understood in the following way in general: Chapter 1: It approaches the basic concepts of the nuclear energy, it describes the physical and chemical composition of the atoms as well as that of the uranium isotopes, the handling of the uranium isotope by means of the nuclear fission until arriving to the operation of the nuclear reactors. Chapter 2: The nuclear fuel cycle is described, the methods for its extraction, its conversion and its enrichment to arrive to the stages of the nuclear fuel management used in the reactors are described. Beginning by the radial design, the axial design and the core design of the nuclear reactor related with the fuel assemblies design. Chapter 3: the optimization methods of nuclear fuel previously used are exposed among those that are: the genetic algorithms method, the search methods based on heuristic rules and the application of the tabu search method, which was used for the development of this thesis. Chapter 4: In this part the used methodology to the

  16. Design and axial optimization of nuclear fuel for BWR reactors; Diseno y optimizacion axial de combustible nuclear para reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Garcia V, M.A

    2006-07-01

    In the present thesis, the modifications made to the axial optimization system based on Tabu Search (BT) for the axial design of BWR fuel type are presented, developed previously in the Nuclear Engineering Group of the UNAM Engineering Faculty. With the modifications what is mainly looked is to consider the particular characteristics of the mechanical design of the GE12 fuel type, used at the moment in the Laguna Verde Nucleo electric Central (CNLV) and that it considers the fuel bars of partial longitude. The information obtained in this thesis will allow to plan nuclear fuel reloads with the best conditions to operate in a certain cycle guaranteeing a better yield and use in the fuel burnt, additionally people in charge in the reload planning will be favored with the changes carried out to the system for the design and axial optimization of nuclear fuel, which facilitate their handling and it reduces their execution time. This thesis this developed in five chapters that are understood in the following way in general: Chapter 1: It approaches the basic concepts of the nuclear energy, it describes the physical and chemical composition of the atoms as well as that of the uranium isotopes, the handling of the uranium isotope by means of the nuclear fission until arriving to the operation of the nuclear reactors. Chapter 2: The nuclear fuel cycle is described, the methods for its extraction, its conversion and its enrichment to arrive to the stages of the nuclear fuel management used in the reactors are described. Beginning by the radial design, the axial design and the core design of the nuclear reactor related with the fuel assemblies design. Chapter 3: the optimization methods of nuclear fuel previously used are exposed among those that are: the genetic algorithms method, the search methods based on heuristic rules and the application of the tabu search method, which was used for the development of this thesis. Chapter 4: In this part the used methodology to the

  17. Application of the wavelet transforms on axial strain calculation in ultrasound elastography

    Institute of Scientific and Technical Information of China (English)

    LUO Jianwen; BAI Jing; SHAO Jinhua

    2006-01-01

    In ultrasound elastography, the axial strain distribution within biological tissues is calculated as the numerical derivative (differentiation) of the estimated axial displacement field. Unfortunately, the numerical derivative is unstable because it can greatly amplify the noises, especially at high frequencies. This work focuses on the axial strain calculation from the estimated axial displacements using wavelet transforms (WTs), including continuous wavelet transforms (CWTs) and discrete wavelet transforms (DWTs). The feasibility of the WT-based method using the quadratic spline function is verified by computer simulations and some phantom data. Results indicate that the WT-based method can effectively reduce the noise amplification in axial strain calculation.

  18. Gossypiboma treated by colonoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hinrichs, C.; Methratta, S.; Ybasco, A.C. [Dept. of Radiology, Univ. of Medicine and Dentistry of New Jersey, Univ. Hospital, Newark (United States)

    2003-04-01

    Gossypibomas are an unusual postoperative complication and are reluctantly reported in the literature. In the past, the patient would require a laparotomy. More recently, they have been treated laparoscopically and percutaneously by interventional radiology. This is the first case report of a gossypiboma treated with colonoscopy. This may represent an addition treatment option for this complication. (orig.)

  19. Gossypiboma treated by colonoscopy

    International Nuclear Information System (INIS)

    Gossypibomas are an unusual postoperative complication and are reluctantly reported in the literature. In the past, the patient would require a laparotomy. More recently, they have been treated laparoscopically and percutaneously by interventional radiology. This is the first case report of a gossypiboma treated with colonoscopy. This may represent an addition treatment option for this complication. (orig.)

  20. TREAT F-series LMFBR loss-of-flow experiments

    International Nuclear Information System (INIS)

    The F-series tests are done to study fuel behavior in an LMFBR LOF accident. These tests are performed in dry (no sodium) capsules to separate out effects of sodium on fuel behavior and, in F3 and subsequent tests, to permit visual observation. Justification for a dry capsule is that the fuel behavior of interest such as fuel-pin breakup and extensive axial motion are assumed to occur after sodium voiding in a LOF accident. Two distinct F-series designs have been subject to TREAT tests. The design used for tests F1 and F2 permitted a study of extensive axial fuel motion and used the fast neutron hodoscope as the principal instrumentation. The second design, used for tests F3 and F4 and to e used for tests F5 and F6, permits a study of fuel pin break-up with high speed photography as the principal instrumentation

  1. Mechanical axial flow blood pump to support cavopulmonary circulation.

    Science.gov (United States)

    Throckmorton, A L; Kapadia, J; Madduri, D

    2008-11-01

    We are developing a collapsible, percutaneously inserted, axial flow blood pump to support the cavopulmonary circulation in infants with a failing single ventricle physiology. An initial design of the impeller for this axial flow blood pump was performed using computational fluid dynamics analysis, including pressure-flow characteristics, scalar stress estimations, blood damage indices, and fluid force predictions. A plastic prototype was constructed for hydraulic performance testing, and these experimental results were compared with the numerical predictions. The numerical predictions and experimental findings of the pump performance demonstrated a pressure generation of 2-16 mm Hg for 50-750 ml/min over 5,500-7,500 RPM with deviation found at lower rotational speeds. The axial fluid forces remained below 0.1 N, and the radial fluid forces were determined to be virtually zero due to the centered impeller case. The scalar stress levels remained below 250 Pa for all operating conditions. Blood damage analysis yielded a mean residence time of the released particles, which was found to be less than 0.4 seconds for both flow rates that were examined, and a maximum residence time was determined to be less than 0.8 seconds. We are in the process of designing a cage with hydrodynamically shaped filament blades to act as a diffuser and optimizing the impeller blade shape to reduce the flow vorticity at the pump outlet. This blood pump will improve the clinical treatment of patients with failing Fontan physiology and provide a unique catheter-based therapeutic approach as a bridge to recovery or transplantation. PMID:19089799

  2. On burr height estimation based on axial drilling force

    Directory of Open Access Journals (Sweden)

    A. Sokołowski

    2010-12-01

    Full Text Available Purpose: The main goal of the research is to build a model of relationship between burr height created during drilling operation and signal representing axial drilling force. Such a model can be applied in diagnostic system for on-line estimation of bur height.Design/methodology/approach: The first applied approach is based on a step by step procedure in which several statistical models were built. The second one is based on specific features of artificial intelligence methods. The artificial neural networks serve as a tool for data selection and integration while the fuzzy logic systems are applied for data integration, only.Findings: The developed algorithm for processing axial drilling force allowed constraining the noise inherent to the drilling process and emphasising the information that could be useful for building considered model. The impact of the properly conducted data selection has been emphasised. Also, importance of providing information represented with axial drilling force has revealed.Research limitations/implications: The developed models need to be checked or improved for practical implementation. Such improvement can be done by introducing other signal features or other cutting parameters as model inputs. Also, analysis of other signals that can be measured during drilling is assumed as a future work.Practical implications: The conducted research reconfirmed possibility of on-line diagnostics of bur height during drilling. Several parameters necessary for such diagnostics have been estimated. This suggests continuing the research in order to design a system that could be applied in industrial conditions.Originality/value: The proposed approach is not a typical since analytical models, FEM models or models basing only on cutting process parameters have been considered, mainly. Such models are limited to two dimensional machining, usually. Besides, application of artificial intelligence methods for data selection and

  3. Time Dependent and Steady Uni-axial Elongational Viscosity

    DEFF Research Database (Denmark)

    Nielsen, Jens K.; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    Here we present measurements of transient and steady uni-axial elongational viscosity, using the Filament Stretching Rheometer1 or FSR1 (see Fig. 1) of the following melts: Four narrow MMD polystyrene (PS) samples with weight-average molar mass Mw in the range of 50k to 390k. Three different bi......-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements....

  4. DYNAMICAL BEHAVIOR OF VISCOELASTIC CYLINDRICAL SHELLS UNDER AXIAL PRESSURES

    Institute of Scientific and Technical Information of China (English)

    程昌钧; 张能辉

    2001-01-01

    The hypotheses of the Kármán-Donnell theory of thin shells with large deflections and the Boltzmann laws for isotropic linear, viscoelastic materials, the constitutive equations of shallow shells are first derived. Then the governing equations for the deflection equations of elastic thin plates. Introducing proper assumptions, an approximate theory for viscoelastic cylindrical shells under axial pressures can be obtained. Finally, the dynamical behavior is studied in detail by using several numerical methods. Dynamical properties,such as, hyperchaos , chaos, strange attractor, limit cycle etc., are discovered.

  5. Axial dispersion via shear-enhanced diffusion in colloidal suspensions

    KAUST Repository

    Griffiths, I. M.

    2012-03-01

    The familiar example of Taylor dispersion of molecular solutes is extended to describe colloidal suspensions, where the fluctuations that contribute to dispersion arise from hydrodynamic interactions. The generic scheme is illustrated for a suspension of particles in a pressure-driven pipe flow, with a concentration-dependent diffusivity that captures both the shear-induced and Brownian contributions. The effect of the cross-stream migration via shear-induced diffusion is shown to dramatically reduce the axial dispersion predicted by classical Taylor dispersion for a molecular solute. Analytic and numerical solutions are presented that illustrate the effect of the concentration dependence of this nonlinear hydrodynamic mechanism. Copyright © EPLA, 2012.

  6. HTS axial flux induction motor with analytic and FEA modeling

    Science.gov (United States)

    Li, S.; Fan, Y.; Fang, J.; Qin, W.; Lv, G.; Li, J. H.

    2013-11-01

    This paper presents a high-temperature superconductor (HTS) axial-flux induction motor, which can output levitation force and torque simultaneously. In order to analyze the character of the force, analytic method and finite element method are adopted to model the motor. To make sure the HTS can carry sufficiently large current and work well, the magnetic field distribution in HTS coil is calculated. An effective method to improve the critical current of HTS coil is presented. Then, AC losses in HTS windings in the motor are estimated and tested.

  7. An Axial Sliding Test for machine elements surfaces

    DEFF Research Database (Denmark)

    Godi, Alessandro; Grønbæk, J.; Mohaghegh, Kamran;

    2012-01-01

    , a housing and a stripwound container. The rod and the sleeve are the two surfaces in relative sliding motion; the stripwound container maintains a constant, but adjustable normal pressure and the housing serves as interface between the sleeve and the container. For carrying out the test, two...... machineries are necessary: a press to provide the normal pressure and a tensile machine to perform the axial movements. The test is calibrated so that the correspondence between the normal pressure and the container advancement is found. Finally, preliminary tests are carried out involving a multifunctional...

  8. Hot Quark Matter with an Axial Chemical Potential

    CERN Document Server

    Gatto, Raoul

    2011-01-01

    We analyze the phase diagram of hot quark matter in presence of an axial chemical potential, $\\mu_5$. The latter is introduced to mimic the chirality transitions induced, in hot Quantum Chromodynamics, by the strong sphaleron configurations. In particular, we study the curvature of the critical line at small $\\mu_5$, the effects of a finite quark mass and of a vector interaction. Moreover, we build the mixed phase at the first order phase transition line, and draw the phase diagram in the chiral density and temperature plane. We finally compute the full topological susceptibility in presence of a background of topological charge.

  9. Echocardiographic Evaluation of the Jarvik 2000 Axial-Flow LVAD

    OpenAIRE

    Stainback, Raymond F.; Croitoru, Mihai; Hernandez, Antonieta; Myers, Timothy J.; Wadia, Yasmin; Frazier, O H

    2005-01-01

    From April 2000 through September 2001, we studied 11 patients with the Jarvik 2000 —a left ventricular assist device with an axial-flow pump that provides continuous blood flow—to determine the echocardiographic characteristics. All patients underwent complete echocardiographic examination, including outflow-graft flow evaluation 24 hours after implantation and each month thereafter for the duration of support. Data were obtained at each pump setting (8,000–12,000 rpm in 1,000-rpm increments...

  10. Exploration of hemolytic model of axial blood pump

    OpenAIRE

    Miao Song; Yu Chang; Yanjiao Xuan

    2012-01-01

    Axial flow blood pumps provides additional energy to blood for heart failure patient, but its implanting destroy environment of blood cells, the direct consequence is hemolysis. According to energy conservation theorem, the severity of pump hemolysis depends on the energy utilization ratio of it. This is a new train of thought in this field. In the light of it, it¡¯s necessary to clear up how much energy used to pump blood, so part of the rest is the energy leading to hemolysis. At present, a...

  11. Failure Processes in Embedded Monolayer Graphene under Axial Compression

    OpenAIRE

    Androulidakis, Charalampos; Koukaras, Emmanuel N.; Frank, Otakar; Tsoukleri, Georgia; Sfyris, Dimitris; Parthenios, John; Pugno, Nicola; Papagelis, Konstantinos; Novoselov, Kostya S.; Galiotis, Costas

    2014-01-01

    Exfoliated monolayer graphene flakes were embedded in a polymer matrix and loaded under axial compression. By monitoring the shifts of the 2D Raman phonons of rectangular flakes of various sizes under load, the critical strain to failure was determined. Prior to loading care was taken for the examined area of the flake to be free of residual stresses. The critical strain values for first failure were found to be independent of flake size at a mean value of –0.60% corresponding to a yield stre...

  12. One-loop corrections to the baryon axial vector current

    Indian Academy of Sciences (India)

    M A Hernández-Ruíz

    2012-10-01

    The symmetry breaking corrections to the pion–baryon couplings vanish to first order in $1/N_{c}$, where $N_{c}$ is the number of colours. Loop graphs with octet and decuplet intermediate states cancel to various orders in $N_{c}$ as a consequence of the large-$N_{c}$ spin-flavour symmetry of QCD baryons. The baryon axial vector current is computed at one-loop order in heavy baryon chiral perturbation theory in the large Nc limit. $1/N_{c}$ corrections in the case of $g_{A}$ in QCD are presented here.

  13. Spatiotemporal focusing does not always improve axial intensity localization

    CERN Document Server

    Cheng, Ya; Wang, Zhaohui; Li, Guihua; Zeng, Bin; He, Fei; Chu, Wei; Yao, Jinping; Qiao, Lingling

    2015-01-01

    We report on an experimental comparison on critical intensities of nonlinear self-focusing in air with conventional focusing and spatiotemporal focusing schemes. Our results show that the conventional focusing with the focal lens completely filled with the incident beam allows for the strongest axial intensity confinement against the self-focusing effect. This is because that in the high-numerical-aperture condition, the focal spot will have a compact size which results in a high focal intensity. Meanwhile, the Rayleigh length of the focused beam will be substantially shortened which efficiently postpones the onset of self-focusing.

  14. On the equivalence between the Schwinger and axial models

    International Nuclear Information System (INIS)

    We show the equivalence between the Schwinger and axial models, in the sense that all Green's functions of one model can be obtained from those of the other, and that both models have the same effective Lagrangian density (and so they have equal partition functions associated with them). In particular, we show that the two models have the same chiral anomaly. Finally it is demonstrated that the Schwinger model can keep gauge invariance for an arbitrary mass, dispensing with an additional gauge group integration. (author)

  15. Lasnex Simulations of Axial Power Diagnostic for ZR

    Science.gov (United States)

    Morris, Heidi

    2015-11-01

    The dynamics of energy loss through diagnostic and/or laser entrance holes with or without shine shields is of inertial confinement fusion experiments envisioned for the National Ignition and ZR Facilities. 2-D radiation-hydrodynamic simulations using Lasnex for power diagnostic experiments using a secondary gold hohlraum fielded at the ZR facility are discussed. The axial radiation exiting the aperture of the dynamic hohlraum is modeled as time and spectrum-dependent 1-D and 2-D sources. Hohlraum energy balance and implications for the measured power are discussed.

  16. ITERATIVE ALGORITHM FOR AXIALLY ACCELERATING STRINGS WITH INTEGRAL CONSTITUTIVE LAW

    Institute of Scientific and Technical Information of China (English)

    Weijia Zhao; Liqun Chen

    2008-01-01

    A numerical method is proposed to simulate the transverse vibrations of a viscoelastic moving string constituted by an integral law.In the numerical computation,the Galerkin method based on the Hermite functions is applied to discretize the state variables,and the RungeKutta method is applied to solve the resulting differential-integral equation system.A linear iterative process is designed to compute the integral terms at each time step,which makes the numerical method more efficient and accurate.As examples,nonlinear parametric vibrations of an axially moving viscoelastic string are analyzed.

  17. Flow field determination at axial pump impeller tip section

    International Nuclear Information System (INIS)

    In most applications the principal limitation on the performance of an axial-flow pump is its cavitation-free operating range, characterized by the nett positive suction head (NPSH). The adverse effects of cavitation are not restricted to impaired performance; noise and vibration levels tend to increase and mechanical integrity of components can be jeopardised, sometimes severely. Cavitation may occur in the inlet region or, in some instances, in the stator blades; however the most usual source of cavitation occurrence is the impeller blading, specifically the tip section

  18. Stability analysis of restricted non-static axial symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, M.; Bhatti, M. Zaeem Ul Haq, E-mail: msharif.math@pu.edu.pk, E-mail: mzaeem.math@gmail.com [Department of Mathematics, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590 (Pakistan)

    2013-11-01

    This paper aims to investigate the instability of very restricted class of non-static axially symmetric spacetime with anisotropic matter configuration. The perturbation scheme is established for the Einstein field equations and conservation laws. The instability range in the Newtonian and post-Newtonian regions are explored by constructing the collapse equation in this scenario. It is found that the adiabatic index plays an important role in the stability analysis which depends upon the physical parameters i.e., energy density and anisotropic pressure of the fluid distribution.

  19. Axial and Radial Gas Holdup in Bubble Column Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Sameer M.; Ansari, Mohashin E Alan; Kene, Pragati T. [RTMNU Nagpur, Nagpur (India)

    2014-06-15

    Bubble column reactors are considered the reactor of choice for numerous applications including oxidation, hydrogenation, waste water treatment, and Fischer-Tropsch (FT) synthesis. They are widely used in a variety of industrial applications for carrying out gas-liquid and gas-liquid-solid reactions. In this paper, the computational fluid dynamics (CFD) model is used for predicting the gas holdup and its distribution along radial and axial direction are presented. Gas holdup increases linearly with increase in gas velocity. Gas bubbles tends to concentrate more towards the center of the column and follows a wavy path.

  20. Axial Anomaly and Index of the Overlap Hypercube Operator

    CERN Document Server

    Adams, D H; Adams, David H.; Bietenholz, Wolfgang

    2003-01-01

    The overlap hypercube fermion is constructed by inserting a lattice fermion with hypercubic couplings into the overlap formula. One obtains a Ginsparg-Wilson fermion, which is more complicated than the standard overlap fermion, but which has improved practical properties. Here we deal with conceptual aspects of the overlap hypercube Dirac operator. In particular we evaluate the axial anomaly and the index, demonstrating that the correct classical continuum limit is recovered. Unlike previous studies of general Ginsparg-Wilson operators, our considerations are non-perturbative and therefore valid in all topological sectors.

  1. Nuclear fuel pellets which can be axially aligned

    International Nuclear Information System (INIS)

    The proposal concerns the shaping of nuclear fuel pellets which are applied as a fuel column, piled up one upon the other in a tube-shaped nuclear fuel can. As damages may occur at the junctions of the fuel material, if the particles are not perfectly aligned, there are made proposals according to the invention concerning the shaping of the opposite end surfaces of the nuclear fuel pellets, which are to facilitate a correct axial alignment. In 48 sub-claims and 22 drawings there is mentioned a multitude of designs which mostly have got an elevated region of convex shape in the center of the end surface of the pellet. (UA)

  2. Material Identification Using a Bi-Axial Test Machine

    OpenAIRE

    Flores, Paulo; Moureaux, Pierre; Habraken, Anne

    2005-01-01

    This paper shows the identification of material parameters for a DC06 IF steel sheet of 0.8 mm by mechanical tests. The experimental equipment used consists of a tensile test machine, a bi-axial test machine able to perform plane-strain and simple shear tests separately or simultaneously and an optical strain gauge. Tensile, plane-strain and simple shear tests were performed at 0°, 45° and 90° from the sheet rolling direction in order to identify Hill 1948 and Hosford 1979 yield criteria. ...

  3. Axial gas flow in irradiated PWR fuel rods

    International Nuclear Information System (INIS)

    Transient and steady state axial gas flow experiments were performed on six irradiated, commercial pressurized water reactor fuel rods at ambient temperature and 533 K. Laminar flow equations, as used in the FRAP-T2 and SSYST fuel behavior codes, were used with the gas flow results to calculate effective fuel rod radial gaps. The results of these analyses were compared with measured gap sizes obtained from metallographic examination of one fuel rod. Using measured gap sizes as input, the SSYST code was used to calculate pressure drops and mass fluxes and the results were compared with the experimental gas flow data

  4. Stability analysis of restricted non-static axial symmetry

    International Nuclear Information System (INIS)

    This paper aims to investigate the instability of very restricted class of non-static axially symmetric spacetime with anisotropic matter configuration. The perturbation scheme is established for the Einstein field equations and conservation laws. The instability range in the Newtonian and post-Newtonian regions are explored by constructing the collapse equation in this scenario. It is found that the adiabatic index plays an important role in the stability analysis which depends upon the physical parameters i.e., energy density and anisotropic pressure of the fluid distribution

  5. Vector and axial anomaly in the Thirring-Wess model

    International Nuclear Information System (INIS)

    We study the two dimensional vector meson model introduced by Thirring and Wess, that is to say the Schwinger model with massive photon and massless fermion. We prove, with a renormalization group approach, that the vector and axial Ward identities are broken by the Adler-Bell-Jackiw anomaly; and we rigorously establish three widely believed consequences: (a) the interacting meson-meson correlation equals a free boson propagator, although the mass is additively renormalized by the anomaly; (b) the anomaly is quadratic in the charge, in agreement with the Adler-Bardeen formula; (c) the fermion-fermion correlation has an anomalous long-distance decay.

  6. $\\eta$-$\\eta$' photoproduction and the axial isoscalar neutral coupling

    CERN Document Server

    Bernabeu, J; Vidal, J; Bernabéu, J; González-Sprinberg, G A; Vidal, J

    1995-01-01

    We show that coherent \\eta and \\etap photoproduction by means of the Primakoff Effect on the proton depends on the strange component of the neutral axial current coupling. We construct polarization asymmetries that are sensitive to this coupling through the \\gamma - Z interference. The \\eta^\\prime is not a Goldstone boson of a spontaneously broken chiral symmetry, but a phenomenological analysis of the \\eta and \\eta^\\prime production through chiral perturbation theory allows to calculate the observables of interest. The polarized proton or polarized photon asymmetries are predicted to be close to 10^{-4} for -q^2 \\sim 0.1-0.5\\;\\mbox{\\rm GeV}^2.

  7. η - η' photoproduction and the axial isoscalar neutral current coupling

    International Nuclear Information System (INIS)

    We show that coherent η and η' photoproduction by means of the Primakoff Effect on the proton depends on the strange component of the neutral axial current coupling. We construct polarization asymmetries that are sensitive to this coupling by the γ-Z interference. The η' is not a Goldstone boson of a spontaneously broken chiral symmetry, but a phenomenological analysis of the η and η' production by chiral perturbation theory allows to calculate the observables of interest. The polarized proton or polarized photon asymmetries are predicted to be close to 10-4 for -q2∝0.1-0.5 GeV2. (orig.)

  8. Calculus of axial force in a mechanism using Lagrange equations

    Directory of Open Access Journals (Sweden)

    Thien Van NGUYEN

    2016-06-01

    Full Text Available Lagrange equations are used to study the motion of a system under the action of known external forces. Besides, based on these equations we can determine the internal force in an arbitrary element of the mechanism acting by active force. If an internal force has to be found, a supplementary mobility related to it is considered in the system. The corresponding internal force for new mobility is found for null values of mobility and of its first and second derivatives. Also the determination of the axial force in the connecting rod of the slider-crank mechanism is presented in this paper as an illustration of this method.

  9. Nucleon axial and tensor charges with dynamical overlap quarks

    CERN Document Server

    Yamanaka, N; Hashimoto, S; Kaneko, T

    2015-01-01

    We report on our calculation of the nucleon axial and tensor charges in 2+1-flavor QCD with dynamical overlap quarks. Gauge ensembles are generated at a single lattice spacing 0.12 fm and at a strange quark mass close to its physical value. We employ the all-mode-averaging technique to calculate the relevant nucleon correlation functions, and the disconnected quark loop is efficiently calculated by using the all-to-all quark propagator. We present our preliminary results for the isoscalar and isovector charges obtained at pion masses $m_\\pi$ = 450 and 540 MeV.

  10. Axial Dark Matter: the case for an invisible Z'

    CERN Document Server

    Lebedev, Oleg

    2014-01-01

    We consider the possibility that fermionic dark matter (DM) interacts with the Standard Model fermions through an axial Z' boson. As long as Z' decays predominantly into dark matter, the relevant LHC bounds are rather loose. Direct dark matter detection does not significantly constrain this scenario either, since dark matter scattering on nuclei is spin--dependent. As a result, for a range of the Z' mass and couplings, the DM annihilation cross section is large enough to be consistent with thermal history of the Universe. In this framework, the thermal WIMP paradigm, which currently finds itself under pressure, is perfectly viable.

  11. Axial dark matter: The case for an invisible Z′

    International Nuclear Information System (INIS)

    We consider the possibility that fermionic dark matter (DM) interacts with the Standard Model fermions through an axial Z′ boson. As long as Z′ decays predominantly into dark matter, the relevant LHC bounds are rather loose. Direct dark matter detection does not significantly constrain this scenario either, since dark matter scattering on nuclei is spin-dependent. As a result, for a range of the Z′ mass and couplings, the DM annihilation cross section is large enough to be consistent with thermal history of the Universe. In this framework, the thermal WIMP paradigm, which currently finds itself under pressure, is perfectly viable

  12. Flow field interference characteristic of axial ring wing configuration

    OpenAIRE

    Qi, Duo; Jinfu, Feng; Jiaqiang, Zhang; Yongli, Li

    2016-01-01

    To analyze the air flow interference between upper and lower wings in axial ring wing configuration, NASA SC(2)-1006 supercritical airfoil is chosen as the basic airfoil. Flow field around the double-wing structure with different relative distances between upper and lower wings is numerically simulated, using SST  turbulence model, and the numerical conclusion about the influence of relative distance D/L on the aerodynamic performance is drawn. It is shown that, at the speed Ma = 0.8, reflect...

  13. Comparison of design methods for axially loaded buckets in sand

    DEFF Research Database (Denmark)

    Vaitkunaite, Evelina; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    A study of the present knowledge about the bucket resistance for axial loading was performed considering analytical and numerical design methods as well as physical models. A case study was performed with two bucket foundations of equal diameter, but different skirt lengths installed in dense sand....... Itwas found that bearing capacity from the surcharge increases approximately twice if the foundation skirt is two times longer. However, the predicted compressive soil capacity can differ by 3.6 times depending on the chosen bearing capacity parameters. Few methods are available for the estimation of...

  14. OTTER 3 - A single channel, axial burnup code

    International Nuclear Information System (INIS)

    OTTER 3 is a single channel, axial burnup code, written in Fortran for the KDF 9 computer, and suitable for studying fuel management schemes of the continuous charge/discharge type. A general fuel shuffling scheme is allowed, and both unidirectional and bidirectional fuel feed can be studied. A 2-group neutron diffusion code is incorporated, the flux equations being solved by the forward elimination - backward substitution technique for the inner problem and a source iteration technique accelerated by Chebyshev extrapolation for the outer problem. (author)

  15. Co-axial ECR plasma system for radioactive ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, M A [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Marion, F [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Stansfield, B [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Paynter, R W [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Sarkar, D [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Sarkissian, A [Plasmionique Inc., 1650 boul. Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Terreault, B [INRS-EMT (Universite du Quebec), 1650 boul. Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada)

    2005-08-01

    A pulsed, co-axial electron cyclotron resonance (ECR, 2.45 GHz) plasma reactor was designed and tested to demonstrate the feasibility of plasma-based radioactive ion implantation ({sup 32}P radioisotope). The geometry of the reactor was designed to produce an efficient implantation of cylindrical implants. Therefore, the reactor is cylindrical in shape, and is equipped with a cylindrical grid in a co-axial geometry. The plasma is created between the wall and the grid; the plasma surrounds the implant, allowing for a radial implantation. A 1 ms microwave pulse creates a plasma in argon, which sputters material from a radioactive cathode. A fraction of the radioisotopes is then ionized, and the ions are implanted into negatively biased metal samples. The plasma was characterized by means of electrostatic probes, giving spatial evaluations of the electron temperature, plasma potential and electron density. Titanium samples were implanted with {sup 32}P during a study that aimed at optimizing the position of the radioactive sputter cathode in the plasma. From an analysis of the distribution of the radioactive fragments, we deduce that the plasma potential has a marked effect on the ion trajectories. In particular, it provides a more uniform implantation distribution than one would otherwise expect. For plasma densities {approx}8 x 10{sup 10} cm{sup -3}, implantation efficiencies as high as 1% are measured; this is about 100 times higher than conventional beam-line ion implantation.

  16. Axial anomaly and index theorem for Dirac-Kaehler fermions

    International Nuclear Information System (INIS)

    Some aspects of topological influence on gauge field theory are analysed, considering the geometry and differential topology methods. A review of concepts of differential forms, fibered spaces, connection and curvature, showing an interpretation of gauge theory in this context, is presented. The question of fermions, analysing in details the Dirac-Kaehler which fermionic particle is considered a general differential form, is studied. It is shown how the explicit expressions in function of the Dirac spinor components vary with the Dirac matrix representation. The Dirac-Kahler equation contains 4 times (in 4 dimensions) the Dirac equation, each particle being associated an ideal at left of the algebra of general differential forms. These ideals and the SU(4) symmetry among them are also studied on the point of view of spinors and, the group of reduction to one of the ideals is identified as the Cartan subalgebra of this SU(4). Finally, the axial anomaly is calculated through the functional determinant given by the Dirac-Kaehler operator. The regularization method is the Seeley's coefficients. From that results a comparison of the index theorems for the twisted complexes of signature and spin, which proportionality is given by the number of the algebra ideals contained in the Dirac-Kaehler equation and which also manifests in the respective axial anomaly equations. (L.C.)

  17. Axial quadrupole phase of a uniaxial spin-1 magnet

    International Nuclear Information System (INIS)

    The axial quadrupole phase of uniaxial spin-1 magnet in an external magnetic field has been investigated. The case of magnetic system with the most general form of single‐ion anisotropy and anisotropic biquadratic exchange interaction is considered. It is shown that the relative magnetization in the molecular field approximation does not depend on temperature and linearly increases with external magnetic field. Two branches of the spin excitation spectrum are determined. The boundary between the axial quadrupole and angular phases is defined by the condition for softening of the spectrum. The critical temperature of the corresponding phase transition considerably depends on the anisotropy constants of the biquadratic exchange interaction. - Highlights: • Quadrupole phase of uniaxial spin-1 magnet in external magnetic field are studied. • Influence of the anisotropic biquadratic exchange interaction is examined. • It is shown that the relative magnetization does not depend on temperature. • Two branches of the spin excitation spectrum are determined. • Dependence of critical temperature from anisotropy constants are built

  18. Wire electrochemical machining with axial electrolyte flushing for titanium alloy

    Institute of Scientific and Technical Information of China (English)

    Qu Ningsong; Fang Xiaolong; Li Wei; Zeng Yongbin; Zhu Di

    2013-01-01

    Titanium and its alloys have found very wide application in aerospace due to their excellent characteristics although their processing is still a challenge.Electrochemical machining is an important issue in the fabrication of titanium and titanium alloys.Wire electrochemical machining (WECM) is mainly used for workpiece cutting under the condition of different thickness plates.It has a great advantage over wire electro-discharge machining,which is the absence of heat-affected zone around the cutting area.Moreover,the wire electrode in WECM could be used repetitively because it is not worn out.Thus,much attention has been paid to WECM.The effective way of removing electrolysis products is of importance to WECM.In this paper,the axial electrolyte flushing is presented to WECM for removing electrolysis products and renewing electrolyte.The Taguchi experiment is conducted to optimize the machining parameters,such as wire feedrate,machining voltage,electrolyte concentration,etc.Experimental results show that WECM with axial electrolyte flushing is a promising issue in the fabrication of titanium alloy (TC1).The feasibility of multi-wire electrochemical machining is also demonstrated to improve the machining productivity of WECM.

  19. Axial design of fuel for BWRs using neural networks

    International Nuclear Information System (INIS)

    In this work a new system of axial optimization of fuel is presented based on a recurrent multi state neural net called RENODC. They are described with detail the main characteristics of this type of neural net (architecture, energy function and actualization of neural states) and like was adapted to the assemble design of nuclear fuel. The fuel design is proven by means of a fuel recharge and pre determined control rod patterns. By this way a good axial fuel design one has, when the thermal limits are fulfilled along the cycle, the reactor stays critic and at least the wanted longitude of the cycle is reached; also the margin of in cold turned off is verified. The assemble of fuel created with RENODC it is substituted by a recharge assemble and it is sought to verify that the energy requirements and aspects of safety are completed. The used cycle corresponds to a balance cycle of 18 months that it can be applied to the Laguna Verde Nucleo electric Central. The tests demonstrate the effectiveness of the system to reach satisfactory results in times of CPU of around 4 hours. This way, it could be proven that the design proposed with a lightly superior enrichment to that of the substituted design, fulfills the energy requirements. In later stages of this project this system will be coupled to the other optimization modules that are already had. (Author)

  20. Paschen testing of ITER prototype cryogenic axial breaks

    International Nuclear Information System (INIS)

    Highlights: ► Breakdown mechanisms in gas and vacuum are explained. ► Breaks and ITER arrangement are described. ► Test setup and test sequence for the breaks are shown. ► The results are presented. -- Abstract: Axial insulation breaks are needed in forced cooled cryogenic high voltage devices for the separation of the high voltage area from the grounded pipe system. The ITER cryogenic axial breaks will be surrounded by good vacuum in case of normal operation but also under vacuum breakdown conditions sufficient dielectric strength is required for a reliable fast discharge of the coil system. A Paschen tight design of the ITER prototype breaks enables high voltage operation independent on the outer vacuum or gas conditions. Consecutively two pretested ITER prototype breaks were integrated in the insulation system of a Paschen test unit and high voltage tested. Two different ways to perform the Paschen testing were used for both breaks. The preparation of the breaks and the test setup are described and the test results are given

  1. Axial length of atomic bomb survivors in Nagasaki

    International Nuclear Information System (INIS)

    We reviewed a series of 778 patients who had cataract surgery during the past 4 years at the Nagasaki Atomic Bomb Memorial Hospital. We evaluated the history of exposure to radiation by atomic bomb in 1945, axial length and state of refraction. All were born before 1945. The series comprised 263 males and 515 females. Their ages averaged 76.5±8.6 years. History of exposure to radiation was present in 356 patients. The remaining 422 patients served as control. There was no difference in the type of cataract between the two groups. High myopia was present in 11 irradiated patients (3.2%) and in 24 patients in the control group (6.0%). The difference was not significant (p=0.083). There was no high myopia among 24 patients who were aged 18 years or less at the time of radiation and who were within 2 km from the epicenter. No difference was present regarding the axial length between the two groups or between both sexes. The present result is not definitive because ''irradiated group'' would include those with little or no exposure and because precise data has not been available about the dosis of radiation. (author)

  2. Observations of impeller tip cavitation in an axial flow pump

    International Nuclear Information System (INIS)

    As the suction head of an axial-flow pump is reduced its performance is degraded by cavitation phenomena. Cavitation may occur in the inlet region or, in some instances, in the stator blades, however the most usual source is the impeller blading, specifically the tip section. Practical difficulties in cavitation testing and in obtaining data from the vicinity of rotating impeller have reduced the availability of consistent information on cavitation effects. The state of knowledge is such that quite fundamental effects may still be overlooked. Furthermore, even if the suction head is not reduced, cavitation resulting from increased blade loading may jeopardize performance. As the pump is throttled up its characteristic the pressures in the suction peak region may drop below the vapor pressure resulting in strong local cavitation. It is usual in the testing of axial pumps to discriminate between the effects of inlet and discharge throttling by plotting performance characteristics as a function of both of these variables. The purpose of the present investigation is not the systematic study of these variables over the whole range but rather the detailed photographic investigation of cavitation patterns in order to elucidate physical phenomena not previously observed or understood

  3. Computational Study of Axial Fatigue for Peripheral Nitinol Stents

    Science.gov (United States)

    Meoli, Alessio; Dordoni, Elena; Petrini, Lorenza; Migliavacca, Francesco; Dubini, Gabriele; Pennati, Giancarlo

    2014-07-01

    Despite their success as primary treatment for vascular diseases, Nitinol peripheral stents are still affected by complications related to fatigue failure. Hip and knee movements during daily activities produce large and cyclic deformations of the superficial femoral artery, that concomitant to the effects of pulsatile blood pressure, may cause fatigue failure in the stent. Fatigue failure typically occurs in cases of very extended lesions, which often require the use of two or more overlapping stents. In this study, finite element models were used to study the fatigue behavior of Nitinol stents when subjected to cyclic axial compression in different conditions. A specific commercial Nitinol stent was chosen for the analysis and subjected to cyclic axial compression typical of the femoral vascular region. Three different configurations were investigated: stent alone, stent deployed in a tube, and two overlapping stents deployed in a tube. Results confirm that stent oversizing has an influence in determining both the mean and amplitude strains induced in the stent and plays an important role in determining the fatigue response of Nitinol stents. In case of overlapping stents, numerical results suggest higher amplitude strains concentrate in the region close to the overlapping portion where the abrupt change in stiffness causes higher cyclic compression. These findings help to explain the high incidence of stent fractures observed in various clinical trials located close to the overlapping portion.

  4. Stability of axially restrained steel columns under temperature action

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The in-plane elastic buckling of a steel column under thermal loading is investigated. The column is pinned at its ends, with two linear elastic springs that model the restraint provided by adjacent members in a structural assemblage or an elastic foundation. Across a section, the temperature is assumed to be linearly distributed. Based on a nonlinear strain-displacement relationship, the energy method is used to obtain the equilibrium and buckling equations. Then the buckling of columns with three different thermal loading cases is studied. The results show that the analytical formulas can be used to evaluate the critical temperature for elastic buckling. The thermal gradient plays a positive role in improving the stability of columns. Comparing these predictions with uniform temperature distribution over cross section, it can be shown that the buckling load is seriously underestimated. It can also be found that axial restraints can significantly affect the column elastic buckling loads. The critical temperature decreases with an increase of restraint stiffness. Furthermore, the effect of axial stiffness increases when increasing the thermal gradients and decreasing the slenderness ratio of columns.

  5. Design Analysis of High-Speed Axial-Flux Generator

    Directory of Open Access Journals (Sweden)

    M. Sadeghierad

    2008-01-01

    Full Text Available Problem Statement: Axial flux permanent magnet machines are regarded as compact high efficiency generators for micro-turbines employed in the distributed power generation systems. High-speed rotor of the generator causes some designing and modeling problems. Sensitivity analysis tasks of the machine parameters are difficult and completely different in comparison with the problems associated with conventional machines. Approach: This article presents a modeling procedure with some details for performance predictions of High-Speed Axial Flux Generator (HSAFG. The FEM results are employed to validate the proposed model. Proper values of inner diameter to outer diameter ratio, plus back iron thickness of two rotor discs located in two ends are serious design problem for a HSAFG. Results: Impacts of these two parameters on the performance characteristics of a HSAFG are investigated in this paper. Their optimum values are determined for the machine by somewhat precise considerations of the output voltage and efficiency. Conclusions/Recommendations: It has been found out that the optimum performance of HSAFG regarding the voltage and efficiency is achieved by the value of inner to outer diameter ratio sited between 0.5-0.65. Moreover, the thickness of the rotor back iron can be designed by trial method to produce sufficient air gap flux and resultant terminal voltage. Adding extra back iron would just increase the rotor inertia with no benefit.

  6. Molecular dynamics study of nanojoining between axially positioned Ag nanowires

    Science.gov (United States)

    Cui, Jianlei; Theogene, Barayavuga; Wang, Xuewen; Mei, Xuesong; Wang, Wenjun; Wang, Kedian

    2016-08-01

    The miniaturization of electronics devices into nanometer scale is indispensable for next-generation semiconductor technology. Ag nanowires (Ag NWs) are considered to be the promising candidates for future electronic circuit owing to the excellent electrical and thermal properties. The nanojoining of axially positioned Ag NWs was performed by molecular dynamics simulation. Through the detailed atomic evolution during the nanojoining, the results indicate that the temperature and the distance between Ag NWs in axial direction have a great impact on nanojoining effect. When the nanojoining temperature is relatively high, the atoms are disordered and the atomic queues become to distort with strong thermodynamic properties and weak effect of metal bonds. At the relatively low temperature, the Ag NWs can be well connected with good junction quality and their own morphology, which is similar to the cold welding without fusion, while the distance between Ag NWs should be controlled for interaction and diffusion of interfacial atoms at nanowires head. When the Ag NWs are placed on Si and SiO2 substrate, because the atomic species and lattice structure of substrate material can differently affect the motions of Ag atoms through the interactive force between the atoms, the nanojoining quality of Ag NWs on Si substrate is better than that on the SiO2 substrate. So, for getting effective and reliable nanojoining without nanosolders and other materials, the temperature, distance and substrate surface should be reasonably controlled and selected, providing helpful theoretical guidance for experiment and application of nanojoining.

  7. Axial length of atomic bomb survivors in Nagasaki

    Energy Technology Data Exchange (ETDEWEB)

    Wakiyama, Harumi; Kishikawa, Yasuhiro; Imamura, Naoki [Nagasaki Atomic Bomb Hospital (Japan); Amemiya, Tsugio [Nagasaki Univ. (Japan). School of Medicine

    2002-03-01

    We reviewed a series of 778 patients who had cataract surgery during the past 4 years at the Nagasaki Atomic Bomb Memorial Hospital. We evaluated the history of exposure to radiation by atomic bomb in 1945, axial length and state of refraction. All were born before 1945. The series comprised 263 males and 515 females. Their ages averaged 76.5{+-}8.6 years. History of exposure to radiation was present in 356 patients. The remaining 422 patients served as control. There was no difference in the type of cataract between the two groups. High myopia was present in 11 irradiated patients (3.2%) and in 24 patients in the control group (6.0%). The difference was not significant (p=0.083). There was no high myopia among 24 patients who were aged 18 years or less at the time of radiation and who were within 2 km from the epicenter. No difference was present regarding the axial length between the two groups or between both sexes. The present result is not definitive because ''irradiated group'' would include those with little or no exposure and because precise data has not been available about the dosis of radiation. (author)

  8. Competition between modes with different axial structures in gyrotrons

    International Nuclear Information System (INIS)

    This study was motivated by some experiments in which it was found that during the voltage rise, instead of expected excitation of a high-frequency parasitic mode, the excitation of a lower-frequency parasitic mode takes place in a certain range of voltages. For explaining this fact, the dependence of start currents of possible competing modes on the beam voltage was carried out in the cold-cavity approximation and by using the self-consistent approach. It was found that in the case of cavities, which consist of the combination of a section of constant radius waveguide and a slightly uptapered waveguide, these two approaches yield completely different results. Thus, experimentally observed excitation of the low-frequency parasitic mode can be explained by the self-consistent modification of the axial profile of the excited field, which has strong influence on the diffractive quality factor of competing modes. This modification is especially pronounced in the case of excitation of modes with many axial variations which can be excited in the region of beam interaction with the backward-wave component of such modes

  9. Nanowelding configuration between carbon nanotubes in axial direction

    International Nuclear Information System (INIS)

    Highlights: ► Nanowelding process could be accomplished at a lower temperature than the melting point of the bulk solder. ► CNTs are connected with solder joints of nodule shape. ► Some silver atoms are captured and dragged into carbon nanotube to form the core filling structures of nanowires. ► Some silver atoms diffuse along the outer walls of SWNTs with the dominant mechanism of capillary wetting. - Abstract: Interconnect technology of carbon nanotubes (CNTs) is essential for functional devices. However, difficulty in the fabrication of the interface between carbon nanotube (CNT) and CNT in axial direction, hindered the quality of connection and practical applications of electrical devices. Also, investigation of dynamic evolution of connection configuration about nanowelding is still lacking. In order to analyze the nanowelding configuration between CNTs in axial direction, the different connection cases are investigated using molecular dynamics simulation. Simulation results show that the nanowelding process could be accomplished at a lower temperature than the melting point of the bulk solder and the CNTs are connected with solder joints of nodule shape. It is also found that metal atoms are captured and dragged into nanotube to form the core filling structures of nanowires during nanowelding. Also, the connection configuration shows that Ag atoms diffuse along the outer walls of SWNTs with the dominant mechanism of capillary wetting, which would increase the contact length to improve the mechanical strength.

  10. P17.35GEINO-10: A PROSPECTIVE OBSERVATIONAL MULTICENTER STUDY OF THE CHARACTERISTICS OF PATIENTS WITH INTRA-AXIAL BRAIN TUMOURS AND THEIR THERAPEUTIC MANAGEMENT IN SPANISH HOSPITALS

    OpenAIRE

    Gil-Gil, M.J.; Sepúlveda, J.M.; Vieitez, J.M. (J. M.); Peñas, R. de las; Fernández-Pérez, I.; Pérez-Segura, P.; Fuster, P.; Martinez-García, M.; Quintanar, T.; del Barco, S.

    2014-01-01

    INTRODUCTION: Primitive brain tumours (BT) represent 2% of adult malignancies. BT patients are treated by different clinical specialists in Spanish hospitals. This means that we did not know with certainty how these patients are treated in Spain. To improve this knowledge the Neuro-Oncology Investigation Spanish Group (GEINO) designed this prospective observational multicenter study. OBJECTIVE: Describe the clinical and pathological characteristics and therapeutic management of intra-axial BT...

  11. Treating and Preventing Burns

    Science.gov (United States)

    ... Issues Listen Español Text Size Email Print Share Treating and Preventing Burns Page Content Article Body Burns ... home, out of children’s reach, and away from heat or ignition sources. Lower the temperature of your ...

  12. How Is Bronchitis Treated?

    Science.gov (United States)

    ... symptoms and make breathing easier. If you have acute bronchitis, your doctor may recommend rest, plenty of fluids, ... treat fever. Antibiotics usually aren't prescribed for acute bronchitis. This is because they don't work against ...

  13. How Is Angina Treated?

    Science.gov (United States)

    ... may be advised to get annual flu shots. Medical Procedures If lifestyle changes and medicines don't control angina, you may need a medical procedure to treat the underlying heart disease. Both angioplasty ( ...

  14. Experiences with treating immigrants

    DEFF Research Database (Denmark)

    Sandhu, Sima; Bjerre, Neele V; Dauvrin, Marie;

    2012-01-01

    human trafficking. Interviews were transcribed and analysed using thematic analysis. RESULTS: The interviews highlighted specific challenges to treating immigrants in mental health services across all 16 countries including complications with diagnosis, difficulty in developing trust and increased risk...

  15. Treating Psoriatic Arthritis

    Science.gov (United States)

    ... to find out more! Email * Zipcode Treating Psoriatic Arthritis Treatment for psoriatic arthritis can relieve pain, reduce swelling, help keep joints ... recommend treatments based on the type of psoriatic arthritis, its severity and your reaction to treatment. Download ...

  16. Hyperlipidemia: Time to Treat?

    OpenAIRE

    Mishkel, Maurice A.

    1985-01-01

    This review emphasizes the practical management of hyperlipidemia (HLD), based on five key references published since 1982. It answers seven basic questions: Who should be screened for HLD? How should they be screened? When should they be screened? What should be expected of the laboratory? Why screen for and treat HLD? What should be expected from treatment of HLD? How should HLD be treated? Dietary and drug management are described.

  17. Electrolyte Concentrates Treat Dehydration

    Science.gov (United States)

    2009-01-01

    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  18. Is axial dispersion within rotating cylinders governed by the Froude number?

    Science.gov (United States)

    Third, J R; Müller, C R

    2012-12-01

    Axial dispersion rates of particles within horizontal rotating cylinders have been calculated for a decade of cylinder diameters. Throughout the range studied the rate of axial dispersion was found to be independent of the cylinder diameter. This phenomenon has been investigated further by spatially resolving the local contribution to the axial dispersion coefficient. This analysis demonstrates that, although the highest rates of axial dispersion occur at the free surface of the bed, there is a significant contribution to axial dispersion throughout the flowing region of the bed. Finally, based on an analogy with a Galton board, a linear relationship is proposed between the local rate of axial dispersion within a horizontal rotating cylinder and the product of the local particle concentration and the local shear rate in a plane perpendicular to the cylinder axis. PMID:23367939

  19. Second harmonic generation of off axial vortex beam in the case of walk-off effect

    Science.gov (United States)

    Chen, Shunyi; Ding, Panfeng; Pu, Jixiong

    2016-07-01

    Process of off axial vortex beam propagating in negative uniaxial crystal is investigated in this work. Firstly, we get the formulae of the normalized electric field and calculate the location of vortices for second harmonic beam in two type of phase matching. Then, numerical analysis verifies that the intensity distribution and location of vortices of the first order original vortex beam depend on the walk-off angle and off axial magnitude. It is shown that, in type I phase matching, the distribution of vortices is symmetrical about the horizontal axis, the separation distance increases as the off axial magnitude increases or the off axial magnitude deceases. However, in type II phase matching, the vortices are symmetrical along with some vertical axis, and increase of the walk-off angle or off axial magnitude leads to larger separation distance. Finally, the case of high order original off axial vortex beam is also investigated.

  20. Forced convection in a circular duct with periodic boundary conditions and axial heat conduction

    Energy Technology Data Exchange (ETDEWEB)

    Barletta, A.; Rossi di Schio, E. [Bologna Univ., Bologna (Italy). Dipt. di Ingegneria Energetica, Nucleare e del Controllo Ambientale

    2000-07-01

    An investigation of the effect of axial heat conduction in the fluid on laminar forced convection is performed in a cylindrical duct with circular cross section. Two different kinds of boundary conditions are analysed: 1, a wall temperature distribution which undergoes a sinusoidal axial variation; 2, a wall heat flux distribution which undergoes a sinusoidal axial variation and such that its mean value is equal to the modulus of the amplitude. Reference is made to the hydrodynamical and thermally developed region, where the temperature distribution is given in case 1 by an axially periodic function and in case 2 by the sum of an axially periodic function and a linear function of the axial coordinate. The temperature distribution within the fluid and the local and mean Nusselt have been evaluated analytically.

  1. Granular axial band formation in rotating tumblers: a discrete element method study

    International Nuclear Information System (INIS)

    The onset mechanism for band formation of a granular mixture in long rotating tumblers is still largely unresolved. We study this issue for axial segregation of binary mixtures having different size particles, using discrete element method simulations. Endwalls initiate axial segregation via an axial flow due to friction. The non-uniform distribution of axial velocity in the flow together with simultaneous radial segregation via percolation results in the axial flow rate of the two types of particles differing in the upstream and downstream portions of the flowing layer. Thus, small particles are driven further from the endwalls, while large particles accumulate at the endwalls. Once this occurs, a cascading mechanism begins so that other bands form due to the gradient in particle concentration near the endwalls. A small axial flow between segregated bands of small and large particles persists even after the bands are fully developed.

  2. Defining and Generating Axial Lines from Street Center Lines for better Understanding of Urban Morphologies

    CERN Document Server

    Liu, Xintao

    2010-01-01

    Axial lines are defined as the longest visibility lines for representing individual linear spaces in urban environments. The least number of axial lines that cover the free space of an urban environment constitute what is often called an axial map. This is a fundamental tool in space syntax, a theory developed by Bill Hillier and his colleagues for characterizing the underlying urban morphologies. For a long time, generating axial lines with help of some graphic software has been a tedious manual process that is criticized for being time consuming, subjective, or even arbitrary. In this paper, we redefine axial lines as the least number of individual straight line segments mutually intersected along natural streets that are generated from street center lines using the Gestalt principle of good continuity. Based on this new definition, we develop an automatic solution to generating the newly defined axial lines from street center lines. We apply this solution to six typical street networks (three from North Am...

  3. Effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells

    Institute of Scientific and Technical Information of China (English)

    Chu-lin YU; Zhi-ping CHEN; Ji WANG; Shun-juan YAN; Li-cai YANG

    2012-01-01

    The effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells is investigated through experimental and numerical buckling analysis using six welded steel cylindrical shell specimens.The relationship between the amplitude of weld reinforcement and the axial plastic buckling critical load is explored.The effect of the material yield strength and the number of circumferential welds on the axial plastic buckling is studied.Results show that circumferential weld reinforcement represents a severe imperfect form of axially compressed welded steel cylindrical shells and the axial plastic buckling critical load decreases with the increment of the mean amplitude of circumferential weld reinforcement.The material yield strength and the number of circumferential welds are found to have no significant effect on buckling waveforms; however,the axial plastic buckling critical load can be decreased to some extent with the increase of the number of circumferential welds.

  4. Launch Lock Assemblies Including Axial Gap Amplification Devices and Spacecraft Isolation Systems Including the Same

    Science.gov (United States)

    Barber, Tim Daniel (Inventor); Hindle, Timothy (Inventor); Young, Ken (Inventor); Davis, Torey (Inventor)

    2014-01-01

    Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion there between. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

  5. THE STABILITY OF AN AXIALLY ACCELERATING BEAM ON SIMPLE SUPPORTS WITH TORSION SPRINGS

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaodong; Chen Liqun

    2005-01-01

    The axially moving beams on simple supports with torsion springs are studied. The general modal functions of the axially moving beam with constant speed have been obtained from the supporting conditions. The contribution of the spring stiffness to the natural frequencies has been numerically investigated. Transverse stability is also studied for axially moving beams on simple supports with torsion springs. The method of multiple scales is applied to the partialdifferential equation governing the transverse parametric vibration. The stability boundary is derived from the solvability condition. Instability occurs if the axial speed fluctuation frequency is close to the sum of any two natural frequencies or is two fold natural frequency of the unperturbed system. It can be concluded that the spring stiffness makes both the natural frequencies and the instability regions smaller in the axial speed fluctuation frequency-amplitude plane for given mean axial speed and bending stiffness of the beam.

  6. Quark-Model Predictions for Axial Charges of Nucleon and N* Resonances

    Directory of Open Access Journals (Sweden)

    Wagenbrunn R.F.

    2010-04-01

    Full Text Available We have investigated the axial charges of the nucleon and N* resonances in a relativistic framework. Besides the axial charge of the nucleon, first predictions are reported for the axial charges of all well-established N* resonances below ∼1.9 GeV as produced by the relativistic constituent quark models relying on Goldstoneboson-exchange and one-gluon-exchange hyperfine interactions. The results for the axial charge of the nucleon are found close to experiment but with somewhat smaller values, similar to modern findings from quantum chromodynamics on the lattice. The predictions of the axial charges of the negative-parity N* (1535 and N*(1650 resonances also agree with what has most recently become available from lattice calculations. We discuss the roles of the axial charges of the N* resonances for the phenomenon of chiral-symmetry restoration possibly occurring in the higher hadron spectra.

  7. Axial (HNF3beta) and retinoic acid receptors are regulators of the zebrafish sonic hedgehog promoter.

    OpenAIRE

    Chang, B E; Blader, P.; Fischer, N.; Ingham, P W; Strähle, U.

    1997-01-01

    The signalling molecule Sonic hedgehog is involved in a multitude of distinct patterning processes during vertebrate embryogenesis. In the nascent body axis of the zebrafish embryo, sonic hedgehog is co-expressed with axial (HNF3beta in mammals), a transcription regulator of the winged helix family. We show here that misexpression of axial leads to ectopic activation of sonic hedgehog expression in the zebrafish, suggesting that axial is a regulator of sonic hedgehog transcription. The sonic ...

  8. Nonlinear Model and Qualitative Analysis for Coupled Axial/Torsional Vibrations of Drill String

    OpenAIRE

    Fushen Ren; Baojin Wang; Suli Chen; Zhigang Yao; Baojun Bai

    2016-01-01

    A nonlinear dynamics model and qualitative analysis are presented to study the key effective factors for coupled axial/torsional vibrations of a drill string, which is described as a simplified, equivalent, flexible shell under axial rotation. Here, after dimensionless processing, the mathematical models are obtained accounting for the coupling of axial and torsional vibrations using the nonlinear dynamics qualitative method, in which excitation loads and boundary conditions of the drill stri...

  9. Shear Behavior of Reinforced Concrete Shear Walls under Tensile Axial Force with Eccentricity

    OpenAIRE

    MIZOGUCHI, Mitsuo; ARAI, Yasuyuki; KUCHIJI, Hideki

    2000-01-01

    A lateral loading test of six reinforced concrete shear walls subjected to an eccentric tensile axial force was carried out to examine their shear behavior. Next facts ware confirmed on the shear strength of the walls subjected to an eccentric tensile axial force. The test results can be evaluat by the shear strength equation [2] considering axial tensile stress. The calculated values given by the (AIJ "Design Guidelines for Earthquake Resistant Reinforced Concrete Buildings Based on Inelasti...

  10. Axial-vector dominance predictions in quasielastic neutrino-nucleus scattering

    CERN Document Server

    Amaro, J E

    2015-01-01

    We use the minimum meson-dominance ansatz compatible with low- and high energy constrains to model the nucleon axial form factor. The parameters of the resulting axial form factor are the masses and widths of the two axial mesons, incorporated as a product of monopoles. By applying the half width rule in a Monte Carlo simulation a distribution of theoretical predictions can be generated for the neutrino-nucleus quasielastic cross section. We test the model by applying it to the $(\

  11. Nucleon's axial-vector form factor in the hard-wall AdS/QCD model

    CERN Document Server

    Mamedov, Shahin; Huseynova, Narmin; Atayev, Ibrahim

    2016-01-01

    The axial-vector form factor of the nucleons is considered in the framework of hard-wall model of holographic QCD. A new interaction term between the bulk gauge and matter fields was included into the interaction Lagrangian. We obtain the axial-vector form factor of nucleons in the boundary QCD from the bulk action using AdS/CFT correspondence. The momentum square dependence of the axial-vector form factor is analysed numerically.

  12. The Dynamics of Stall and Surge Behavior in Axial-Centrifugal Compressors

    OpenAIRE

    Cousins, William T.

    1997-01-01

    The phenomena of stall and surge in axial-centrifugal compressors is investigated through high-response measurements of both the pressure field and the flowfield throughout the surge cycle. A unique high-response forward-facing and aft-facing probe provides flow information. Several axial-centrifugal compressors are examined, both in compressor rigs and engines. Extensive discussion is presented on the differences in axial and centrifugal rotors and their effect on the system response char...

  13. Detection of Forces and Displacements along the Axial Direction in an Optical Trap

    OpenAIRE

    Deufel, Christopher; Wang, Michelle D.

    2005-01-01

    We present measurements of the forces on, and displacements of, an optically trapped bead along the propagation direction of the trapping laser beam (the axial direction). In a typical experimental configuration, the bead is trapped in an aqueous solution using an oil-immersion, high-numerical-aperture objective. This refractive index mismatch complicates axial calibrations due to both a shift of the trap center along the axial direction and spherical aberrations. In this work, a known DNA te...

  14. Sum rule analysis of vector and axial-vector spectral functions with excited states in vacuum

    OpenAIRE

    Hohler, Paul M.; Rapp, Ralf

    2012-01-01

    We simultaneously analyze vector and axial-vector spectral functions in vacuum using hadronic models constrained by experimental data and the requirement that Weinberg-type sum rules are satisfied. Upon explicit inclusion of an excited vector state, viz. rho', and the requirement that the perturbative continua are degenerate in vector and axial-vector channels, we deduce the existence of an excited axial-vector resonance state, a1', in order that the Weinberg sum rules are satisfied. The resu...

  15. CAMDYN: a new model to describe the axial motion of molten fuel inside the pin of a fast breeder reactor during accident conditions

    International Nuclear Information System (INIS)

    The new in-pin fuel motion model CAMDYN (Cavity Material Dynamics) describes the axial motion of both partially and fully molten fuel inside the pin of a fast breeder reactor during accident conditions. The motion of the two types of molten fuel and the imbedded fission gas bubbles is treated both before and after cladding failure. The basic modelling approach consists of the treatment of two one-dimensional flows which are coupled by interaction terms. Each of these flows is treated compressively and with axially variable flow cross sections. The mass and energy equations of both fields are solved explicitly using upwind differencing on a fixed Eulerian grid. The two momentum equations are solved simultaneously, using the convective momentum fluxes of the previous timestep. Both partially and fully molten fuel can move axially into a central hole extending to the plenum in the case of certain hollow pellet designs. The fuel temperature calculation includes the determination of a radial temperature profile. A simple conduction freezing model is included. After cladding failure, ejection into the coolant channel is modeled

  16. Plasticity around an Axial Surface Crack in a Cylindrical Shell

    DEFF Research Database (Denmark)

    Krenk, Steen

    1979-01-01

    field in an axially cracked cylindrical shell arising from use of classical eighth order shallow shell theory is removed when use is made of a tenth order shell theory which accounts for transverse shear deformations. Although the membrane stresses are only moderately affected, the influence on the...... Ratwani,3–5 it generalises Dugdale's assumption of a concentrated yield zone in the plane of the crack but, contrary to that model, transverse shear effects are included and a continuous stress distribution is assumed in the yield zone. The inherent difficulties arising from the use of shell theory to...... model a three-dimensional problem can be overcome when the crack is sufficiently deep and the material is so ductile that full yield of the section around the crack develops before failure. In that case the calculations confirm the initial assumption of separation of the crack surfaces and the sides of...

  17. Nucleon axial form factors from two-flavour Lattice QCD

    CERN Document Server

    Junnarkar, P M; Djukanovic, D; von Hippel, G; Hua, J; Jäger, B; Meyer, H B; Rae, T D; Wittig, H

    2014-01-01

    We present preliminary results on the axial form factor $G_A(Q^2)$ and the induced pseudoscalar form factor $G_P(Q^2)$ of the nucleon. A systematic analysis of the excited-state contributions to form factors is performed on the CLS ensemble `N6' with $m_\\pi = 340 \\ \\text{MeV}$ and lattice spacing $a \\sim 0.05 \\ \\text{fm}$. The relevant three-point functions were computed with source-sink separations ranging from $t_s \\sim 0.6 \\ \\text{fm}$ to $t_s \\sim \\ 1.4 \\ \\text{fm}$. We observe that the form factors suffer from non-trivial excited-state contributions at the source-sink separations available to us. It is noted that naive plateau fits underestimate the excited-state contributions and that the method of summed operator insertions correctly accounts for these effects.

  18. Hamilton's equations for a fluid membrane: axial symmetry

    International Nuclear Information System (INIS)

    Consider a homogeneous fluid membrane, or vesicle, described by the Helfrich-Canham energy, quadratic in the mean curvature. When the membrane is axially symmetric, this energy can be viewed as an 'action' describing the motion of a particle; the contours of equilibrium geometries are identified with particle trajectories. A novel Hamiltonian formulation of the problem is presented which exhibits the following two features: (i) the second derivatives appearing in the action through the mean curvature are accommodated in a natural phase space and (ii) the intrinsic freedom associated with the choice of evolution parameter along the contour is preserved. As a result, the phase space involves momenta conjugate not only to the particle position but also to its velocity, and there are constraints on the phase space variables. This formulation provides the groundwork for a field theoretical generalization to arbitrary configurations, with the particle replaced by a loop in space

  19. Nonlinear Interactions between Slender Structures and Axial Flow

    Science.gov (United States)

    Du, Li

    2015-03-01

    For decades, dynamic behaviors of a slender structure with axial flow have been extensively studied. However, the governing equation based on expansions of small quantities is complicatedly-expressed and can be inappropriate as amplitude becomes considerably large. In this research, we are dedicated to finding an approach to study the nonlinear dynamics of a fluid-conveying slender strcture with arbitrary amplitude. By introducing the Intrinsic Coordinate, we find a concise way to describe the configuration of the system. Differential relations of such coordinate are studied and the rigorous nonlinear equation of motion is derived. Then rather than small-deflection approximation, linear dynamics are studied using Argand Diagram under a weaker condition named low-varying approximation. Nonlinear properties including Hopf bifurcation, limit-cycle motion and vibration frequencies are studied theoretically and experimentally.

  20. Static Tension Tests on Axially Loaded Pile Segments in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    showed best agreement with the traditional design method given in the American Petroleum Institute (API) design code. When t-z curves obtained from the test results were compared to t-z curve formulations found in the literature, the Zhang formulation gave good predictions of the initial and post......This paper provides laboratory test results of static axially loaded piles in sand. With a newly developed test setup, the pile-soil interface friction was investigated by using an open-ended steel pile segment with a diameter of 0.5 m. Use of a pile length of 1 m enabled the pile-soil interface...... friction to be analyzed at a given soil horizon while increasing the vertical effective stress in the sand. Test results obtained by this approach can be analyzed as single t-z curves and compared to predictions of unit shaft friction from current design methods for offshore foundations. The test results...