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Sample records for axis vegf-flt-1 fms-like

  1. Impaired signaling through the Fms-like tyrosine kinase 3 receptor increases osteoclast formation and bone damage in arthritis.

    Science.gov (United States)

    Svensson, Mattias N D; Erlandsson, Malin C; Jonsson, Ing-Marie; Andersson, Karin M E; Bokarewa, Maria I

    2016-03-01

    Osteoclasts are bone-resorbing cells that accumulate in the joints of patients with rheumatoid arthritis causing severe bone damage. Fms-like tyrosine kinase 3 ligand is enriched in the synovial fluid of patients with rheumatoid arthritis, and local exposure to Fms-like tyrosine kinase 3 ligand aggravates arthritis in mice. Because Fms-like tyrosine kinase 3 ligand has been suggested to facilitate osteoclast differentiation, we asked whether Fms-like tyrosine kinase 3 ligand affects bone remodeling in arthritis. The effect of Fms-like tyrosine kinase 3 signaling on osteoclast development was studied by immunohistochemistry in methylated bovine serum albumin-induced arthritis using mice that lack the gene for Flt3l (Flt3L(-/-)) and by an in vitro assay. Bone and joint changes were studied morphologically and by microcomputer tomography. We found that Flt3L(-/-) mice had increased accumulations of osteoclasts in the periarticular area of the arthritic joint. This triggered bone destruction and trabecular bone loss. The increased number of osteoclasts in Flt3L(-/-) mice may be a consequence of insufficient expression of interferon regulatory factor 8. Treatment of Flt3L(-/-) mice with Fms-like tyrosine kinase 3 ligand increased expression of interferon regulatory factor 8, reduced the number of osteoclasts in arthritic mice, and promoted trabecular bone formation. Finally, the reduced number of regulatory T cells in the bone marrow of Flt3L(-/-) mice could further contribute to the increased osteoclastogenesis by reducing the ratio of regulatory T cells to T helper 17 cells. This study shows that Fms-like tyrosine kinase 3 ligand may serve as a negative regulator of osteoclast development by promoting transcription of interferon regulatory factor 8 and sustaining a balance between protective regulatory T cells and pathogenic T helper 17 cells in the pathogenesis of arthritis.

  2. Gamma-linolenic acid inhibits both tumour cell cycle progression and angiogenesis in the orthotopic C6 glioma model through changes in VEGF, Flt1, ERK1/2, MMP2, cyclin D1, pRb, p53 and p27 protein expression

    Directory of Open Access Journals (Sweden)

    Colquhoun Alison

    2009-03-01

    expression of VEGF, Flt1, ERK1, ERK2, MMP2, Cyclin D1, pRb, p53 and p27. Combination therapy using drugs with other, complementary targets and GLA could lead to gains in treatment efficacy in this notoriously difficult to treat tumour.

  3. Soluble fms-like tyrosine kinase 1 promotes angiotensin II sensitivity in preeclampsia.

    Science.gov (United States)

    Burke, Suzanne D; Zsengellér, Zsuzsanna K; Khankin, Eliyahu V; Lo, Agnes S; Rajakumar, Augustine; DuPont, Jennifer J; McCurley, Amy; Moss, Mary E; Zhang, Dongsheng; Clark, Christopher D; Wang, Alice; Seely, Ellen W; Kang, Peter M; Stillman, Isaac E; Jaffe, Iris Z; Karumanchi, S Ananth

    2016-07-01

    Preeclampsia is a hypertensive disorder of pregnancy in which patients develop profound sensitivity to vasopressors, such as angiotensin II, and is associated with substantial morbidity for the mother and fetus. Enhanced vasoconstrictor sensitivity and elevations in soluble fms-like tyrosine kinase 1 (sFLT1), a circulating antiangiogenic protein, precede clinical signs and symptoms of preeclampsia. Here, we report that overexpression of sFlt1 in pregnant mice induced angiotensin II sensitivity and hypertension by impairing endothelial nitric oxide synthase (eNOS) phosphorylation and promoting oxidative stress in the vasculature. Administration of the NOS inhibitor l-NAME to pregnant mice recapitulated the angiotensin sensitivity and oxidative stress observed with sFlt1 overexpression. Sildenafil, an FDA-approved phosphodiesterase 5 inhibitor that enhances NO signaling, reversed sFlt1-induced hypertension and angiotensin II sensitivity in the preeclampsia mouse model. Sildenafil treatment also improved uterine blood flow, decreased uterine vascular resistance, and improved fetal weights in comparison with untreated sFlt1-expressing mice. Finally, sFLT1 protein expression inversely correlated with reductions in eNOS phosphorylation in placental tissue of human preeclampsia patients. These data support the concept that endothelial dysfunction due to high circulating sFLT1 may be the primary event leading to enhanced vasoconstrictor sensitivity that is characteristic of preeclampsia and suggest that targeting sFLT1-induced pathways may be an avenue for treating preeclampsia and improving fetal outcomes. PMID:27270170

  4. FMS-like tyrosine kinase 3 ligand treatment does not ameliorate experimental rapidly progressive glomerulonephritis.

    Directory of Open Access Journals (Sweden)

    Joanna R Ghali

    Full Text Available Fms-like tyrosine kinase 3-ligand (FL is a growth factor that may expand dendritic cell and regulatory T cell populations. We hypothesised that FL-induced regulatory T cells would protect mice from experimental rapidly progressive glomerulonephritis. To determine if FL was able to enhance regulatory T cell populations, C57BL/6 mice received 10 days of daily intraperitoneal injections of either FL or phosphate buffered saline. To induce accelerated autologous-phase anti-mouse glomerular basement membrane glomerulonephritis, mice were sensitized to sheep globulin 4 days prior to the induction of glomerulonephritis with sheep anti-mouse glomerular basement membrane globulin, and experiments ended 10 days later. FL was administered before, throughout and during the sensitization phase of this glomerulonephritis model. Renal disease and systemic immunity to the nephritogenic antigen were assessed. FL increased regulatory T cell and plasmacytoid dendritic cell proportions within spleen and lymph nodes. FL administration prior to glomerulonephritis did not protect mice from renal injury. When FL was given throughout the model, FL treated mice had reduced survival, with more interstitial neutrophils and glomerular CD11c+ cells than controls. Systemic immune responses showed increased IL-17A production from splenocytes, with more CD11c+ cells, but reduced plasmacytoid dendritic cell proportions in spleen and lymph nodes, despite increased regulatory T cell proportions. Under homeostatic conditions, FL expanded regulatory T cell and plasmacytoid dendritic cell populations, but FL enhanced systemic inflammatory responses and conventional dendritic cell populations when given during experimental glomerulonephritis, suggesting selective attempts to suppress pathogenic immunity by dendritic cell manipulation may be harmful.

  5. Removal of Soluble Fms-Like Tyrosine Kinase-1 by Dextran Sulfate Apheresis in Preeclampsia.

    Science.gov (United States)

    Thadhani, Ravi; Hagmann, Henning; Schaarschmidt, Wiebke; Roth, Bernhard; Cingoez, Tuelay; Karumanchi, S Ananth; Wenger, Julia; Lucchesi, Kathryn J; Tamez, Hector; Lindner, Tom; Fridman, Alexander; Thome, Ulrich; Kribs, Angela; Danner, Marco; Hamacher, Stefanie; Mallmann, Peter; Stepan, Holger; Benzing, Thomas

    2016-03-01

    Preeclampsia is a devastating complication of pregnancy. Soluble Fms-like tyrosine kinase-1 (sFlt-1) is an antiangiogenic protein believed to mediate the signs and symptoms of preeclampsia. We conducted an open pilot study to evaluate the safety and potential efficacy of therapeutic apheresis with a plasma-specific dextran sulfate column to remove circulating sFlt-1 in 11 pregnant women (20-38 years of age) with very preterm preeclampsia (23-32 weeks of gestation, systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, new onset protein/creatinine ratio >0.30 g/g, and sFlt-1/placental growth factor ratio >85). We evaluated the extent of sFlt-1 removal, proteinuria reduction, pregnancy continuation, and neonatal and fetal safety of apheresis after one (n=6), two (n=4), or three (n=1) apheresis treatments. Mean sFlt-1 levels were reduced by 18% (range 7%-28%) with concomitant reductions of 44% in protein/creatinine ratios. Pregnancy continued for 8 days (range 2-11) and 15 days (range 11-21) in women treated once and multiple times, respectively, compared with 3 days (range 0-14) in untreated contemporaneous preeclampsia controls (n=22). Transient maternal BP reduction during apheresis was managed by withholding pre-apheresis antihypertensive therapy, saline prehydration, and reducing blood flow through the apheresis column. Compared with infants born prematurely to untreated women with and without preeclampsia (n=22 per group), no adverse effects of apheresis were observed. In conclusion, therapeutic apheresis reduced circulating sFlt-1 and proteinuria in women with very preterm preeclampsia and appeared to prolong pregnancy without major adverse maternal or fetal consequences. A controlled trial is warranted to confirm these findings.

  6. Fms-like tyrosine kinase-3 ligand alters antigen-specific responses to infections after severe burn injury

    OpenAIRE

    Bohannon, Julia; Fang, Geping; Cui, Weihua; Sherwood, Edward; Toliver-Kinsky, Tracy

    2009-01-01

    Burn patients are susceptible to opportunistic infections due partly to decreased immune functions, especially Th1-driven antigen-specific responses, which are regulated by dendritic cells. The dendritic cell growth factor, fms-like tyrosine kinase-3 ligand (FL), has been shown to increase resistance to P. aeruginosa, in a dendritic cell-dependent manner, in a mouse model of burn wound infection. The specific mechanisms of protection are not known. This study tested the hypothesis that FL can...

  7. Alteration and potential role of soluble fms-like tyrosine kinase receptor 1 in preeclampsia

    Institute of Scientific and Technical Information of China (English)

    LI Yi; LI Dong-hong; YAO Yuan-qing; ZHAO Hong-xi; ZHANG Chun-li; HUANG Liang

    2005-01-01

    Objective:To investigate the alteration of serum soluble fms-like tyrosine kinase receptor 1 (sFlt-1), the possible cause in preeclampsia, the relationship between altered sFlt-1 and the development of pregnancy. Methods: Semi-quantitative RT-PCR was carried out to detect the level of sFlt-1 mRNA in placental tissue of 10 preeclampsia (study group) and 10 normotensive pregnancies (control group); ELISA was used to detect the serum level of sFlt-1 in peripheral venous blood and uterine venous blood in control group (n=35) and study group (n=35), and furthermore to detect the volume of peripheral venous blood sFlt-1 in early, middle and later pregnancies. Results: sFlt-1 mRNA of placental tissue was significantly higher in preeclampsia than that in normal pregnancy. The serum level of sFlt-1 of peripheral vein in preeclampsia was higher than that in normal pregnancy ([ 5639.6±3190.5] pg/ml vs[ 2194.4±635.8 ] pg/ml, P<0.01) , so did the serum sFlt-1 of uterine vein in preeclampsia and control group ([7673.3±2295.8] pg/ml vs[ 3056.6±784.6] pg/ml, P<0.01), indicating that the volume of sFlt-1 of uterine vein blood was significantly higher than that of peripheral venous blood (P<0.01). The serum level of sFlt-1 in early, middle and later pregnancy were (31.7±19.6) pg/ml (n=10), (994.0±302.1) pg/ml (n=10), (2194.4±635.8) pg/ml (n=35), respectively, showing that the level of sFlt-1 in peripheral venous blood increasingly elevated with the development of pregnancy (P<0.01). Conclusion: Preeclampsia is associated with increased level of sFlt-1 which might be largely from placenta during pregnancy.

  8. Expression of the fms-like tyrosine kinase 4 gene becomes restricted to lymphatic endothelium during development.

    OpenAIRE

    Kaipainen, A; Korhonen, J; Mustonen, T; van Hinsbergh, V W; G. H. Fang; Dumont, D,; Breitman, M; Alitalo, K

    1995-01-01

    We have recently cloned the human fms-like tyrosine kinase 4 gene FLT4, whose protein product is related to two vascular endothelial growth factor receptors FLT1 and KDR/FLK1. Here the expression of FLT4 has been analyzed by in situ hybridization during mouse embryogenesis and in adult human tissues. The FLT4 mRNA signals first became detectable in the angioblasts of head mesenchyme, the cardinal vein, and extraembryonally in the allantois of 8.5-day postcoitus (p.c.) embryos. In 12.5-day p.c...

  9. Clonal evolution of AML on novel FMS-like tyrosine kinase-3 (FLT3 inhibitor therapy with evolving actionable targets

    Directory of Open Access Journals (Sweden)

    Pashtoon M. Kasi

    2016-01-01

    Full Text Available For acute myeloid leukemia (AML, identification of activating mutations in the FMS-like tyrosine kinase-3 (FLT3 has led to the development of several FLT3-inhibitors. Here we present clinical and next generation sequencing data at the time of progression of a patient on a novel FLT3-inhibitor clinical trial (ASP2215 to show that employing therapeutic interventions with these novel targeted therapies can lead to consequences secondary to selective pressure and clonal evolution of cancer. We describe novel findings alongside data on treatment directed towards actionable aberrations acquired during the process. (Clinical Trial: NCT02014558; registered at: 〈https://clinicaltrials.gov/ct2/show/NCT02014558〉

  10. Maternal soluble fms-like tyrosine kinase-1, placental growth factor, plasminogen activator inhibitor-2, and folate concentrations and early fetal size : the Generation R study

    NARCIS (Netherlands)

    Bouwland-Both, Marieke I.; Steegers, Eric A. P.; Lindemans, Jan; Russcher, Henk; Hofman, Albert; Geurts-Moespot, Anneke J.; Sweep, Fred C. G. J.; Jaddoe, Vincent W. V.; Steegers-Theunissen, Regine P. M.

    2013-01-01

    OBJECTIVE: Fetal growth is dependent on adequate development of the placenta. Impaired angiogenesis and vasculogenesis in early pregnancy compromises placental and embryonic development. The proteins soluble fms-like tyrosine kinase (sFlt)-1, placental growth factor (PlGF), and plasminogen activator

  11. Increased serum levels of anti-angiogenic factors soluble fms-like tyrosine kinase and soluble endoglin in sickle cell disease

    NARCIS (Netherlands)

    Landburg, P.P.; Elsenga, H.; Schnog, J.B.; Duits, A.J.

    2008-01-01

    The anti-angiogenic factors soluble fms-like tyrosine kinase (sFlt)-1 and soluble endoglin (sEng) have been shown to be of importance in angiogenesis by sequestering and inhibiting vascular endothelial growth factor, placenta-like growth factor and transforming growth factor-beta(1) signaling. Given

  12. Relation between circulating angiotensin II type 1 receptor agonistic autoantibodies and soluble fms-like tyrosine kinase 1 in the pathogenesis of preeclampsia

    NARCIS (Netherlands)

    H. Stepan (Holger); R. Faber (Renaldo); N. Wessel; G. Wallukat (Gerd); H.P. Schultheiss; T. Walther (Thomas)

    2006-01-01

    textabstractContext: Placental and circulatory soluble fms-like tyrosine kinase 1 (sFlt1) has proven to be elevated in pregnant women with preeclampsia, a disease characterized by hypertension, proteinuria, and endothelial dysfunction. Recent studies also demonstrated an autoantibody against the ang

  13. In vivo evidence for an instructive role of fms-like tyrosine kinase-3 (FLT3) ligand in hematopoietic development.

    Science.gov (United States)

    Tsapogas, Panagiotis; Swee, Lee Kim; Nusser, Anja; Nuber, Natko; Kreuzaler, Matthias; Capoferri, Giuseppina; Rolink, Hannie; Ceredig, Rhodri; Rolink, Antonius

    2014-04-01

    Cytokines are essential regulators of hematopoiesis, acting in an instructive or permissive way. Fms-like tyrosine kinase 3 ligand (FLT3L) is an important cytokine for the development of several hematopoietic populations. Its receptor (FLT3) is expressed on both myeloid and lymphoid progenitors and deletion of either the receptor or its ligand leads to defective developmental potential of hematopoietic progenitors. In vivo administration of FLT3L promotes expansion of progenitors with combined myeloid and lymphoid potential. To investigate further the role of this cytokine in hematopoietic development, we generated transgenic mice expressing high levels of human FLT3L. These transgenic mice displayed a dramatic expansion of dendritic and myeloid cells, leading to splenomegaly and blood leukocytosis. Bone marrow myeloid and lymphoid progenitors were significantly increased in numbers but retained their developmental potential. Furthermore, the transgenic mice developed anemia together with a reduction in platelet numbers. FLT3L was shown to rapidly reduce the earliest erythroid progenitors when injected into wild-type mice, indicating a direct negative role of the cytokine on erythropoiesis. We conclude that FLT3L acts on multipotent progenitors in an instructive way, inducing their development into myeloid/lymphoid lineages while suppressing their megakaryocyte/erythrocyte potential. PMID:24463214

  14. Suppressed Production of Soluble Fms-Like Tyrosine Kinase-1 Contributes to Myocardial Remodeling and Heart Failure.

    Science.gov (United States)

    Seno, Ayako; Takeda, Yukiji; Matsui, Masaru; Okuda, Aya; Nakano, Tomoya; Nakada, Yasuki; Kumazawa, Takuya; Nakagawa, Hitoshi; Nishida, Taku; Onoue, Kenji; Somekawa, Satoshi; Watanabe, Makoto; Kawata, Hiroyuki; Kawakami, Rika; Okura, Hiroyuki; Uemura, Shiro; Saito, Yoshihiko

    2016-09-01

    Soluble fms-like tyrosine kinase-1 (sFlt-1), an endogenous inhibitor of vascular endothelial growth factor and placental growth factor, is involved in the pathogenesis of cardiovascular disease. However, the significance of sFlt-1 in heart failure has not been fully elucidated. We found that sFlt-1 is decreased in renal failure and serves as a key molecule in atherosclerosis. In this study, we aimed to investigate the role of the decreased sFlt-1 production in heart failure, using sFlt-1 knockout mice. sFlt-1 knockout mice and wild-type mice were subjected to transverse aortic constriction and evaluated after 7 days. The sFlt-1 knockout mice had significantly higher mortality (52% versus 15%; P=0.0002) attributable to heart failure and showed greater cardiac hypertrophy (heart weight to body weight ratio, 8.95±0.45 mg/g in sFlt-1 knockout mice versus 6.60±0.32 mg/g in wild-type mice; Pfailure through upregulation of monocyte chemoattractant protein-1 expression in pressure-overloaded heart. PMID:27480835

  15. Fms-like Tyrosine Kinase (FLT) 3 and FLT3 Internal Tandem Duplication in Different Types of Adult Leukemia: Analysis of 147 Patients

    OpenAIRE

    Peng, Hong-ling; Zhang, Guang-Sen; Gong, Fan-Jie; Shen, Jian-Kai; Zhang, Yang; Xu, Yun-Xiao; Zheng, Wen-Li; Dai, Chong-Wen; Pei, Min-Fei; YANG, JUN-JIE

    2008-01-01

    Aim To assess the expression level of fms-like tyrosine kinase 3 (FLT3), the incidence of FLT3/internal tandem duplications (ITD) mutation, and prognostic value of FLT3 changes in different types of adult leukemia. Methods Bone marrow mononuclear cells were isolated from 147 adult patients with leukemia. Reverse transcriptase polymerase chain reaction (PCR) was used to screen FLT3/ITD mutation and quantitative PCR was performed to evaluate the expression of the FLT3 transcri...

  16. Murine germinal center B cells require functional Fms-like tyrosine kinase 3 signaling for IgG1 class-switch recombination.

    Science.gov (United States)

    Svensson, Mattias N D; Andersson, Karin M E; Wasén, Caroline; Erlandsson, Malin C; Nurkkala-Karlsson, Merja; Jonsson, Ing-Marie; Brisslert, Mikael; Bemark, Mats; Bokarewa, Maria I

    2015-12-01

    Switched antibody classes are important for efficient immune responses. Aberrant antibody production to otherwise harmless antigens may result in autoimmunity. The protein kinase fms-like tyrosine kinase 3 receptor (Flt3) has an important role during early B-cell development, but the role of Flt3 in peripheral B cells has not been assessed before. Herein we describe a previously unappreciated role for Flt3 in IgG1 class-switch recombination (CSR) and production. We show that Flt3 is reexpressed on B-cell lymphoma 6(+) germinal center B cells in vivo and following LPS activation of peripheral B cells in vitro. Absence of Flt3 signaling in Flt3 ligand-deficient mice results in impaired IgG1 CSR and accumulation of IgM-secreting plasma cells. On activated B cells, Flt3 is coexpressed and functions in synergy with the common-gamma chain receptor family. B cells from Flt3 ligand-deficient mice have impaired IL-4R signaling, with reduced phosphorylation of signal transducer and activator of transcription (Stat) 6, and demonstrate a failure to initiate CSR to IgG1 with low expression of γ1 germ-line transcripts, resulting in impaired IgG1 production. Thus, functional synergy between Flt3 and IL-4R signaling is critical for Stat-mediated regulation of sterile γ1 germ-line transcripts and CSR to IgG1. PMID:26627255

  17. Soluble fms-like tyrosine kinase-1 and vascular endothelial growth factor:Novel markers for unexplained early recurrent pregnancy loss

    Institute of Scientific and Technical Information of China (English)

    Mahmoud Fathy; Hassan

    2014-01-01

    Objective:To evaluate the role of soluble fms-like tyrosine kinase-1(sFlt-1) and vascular endothelial growth factor(VEGF) for prediction of pregnancy loss in patients with history of unexplained early recurrent pregnancy loss(RPL).Methods:A prospective case control study was conducted in42 women with history of unexplained earlyRPL, and170 pregnant controls with history of uncomplicated pregnancy.We measured maternal serum sFlt-1 andVEGF at gestational age6-9 weeks as predictor for pregnancy loss.Results:Mean serum levels of sFlt-1 andVEGF were significantly higher inRPL group than controls(10439.7±385.4vs3304.5±104.8;P<0.0001, for sFlt-1, and1885.0±98.3 vs709.8±24.8;P<0.0001, forVEGF).Receiver operating characteristic(ROC) curves analyses established that sFlt-1 andVEGF were able to discriminate women at risk of developing pregnancy loss with area underROC curve0.970 for sFlt-1 and0.953 forVEGF.Cutoff value of5159.5 pg/mL for sFlt-1 was predictor for early pregnancy loss with 95.2% sensitivity,91.2% specificity, and odds ratio(OR)206 [95%confidence interval(CI),45.4-941].Cutoff value of915.5 pg/mL forVEGF was predictor for early pregnancy loss with92.9% sensitivity,90.6% specificity, andOR125 [95%CI:34.7-451].Conclusion:These data advocate a relationship between sFlt-1,VEGF, andRPL suggesting that the high levels of sFlt-1 andVEGF might be associated with the pathogenesis ofRPL.

  18. Altered Level of Soluble fms-like Tyrosine Kinase 1 (sFlt1 and Hypoxia Inducible Factor-1alpha (HIF-1alpha in Normotensive Pregnancy and Preeclampsia

    Directory of Open Access Journals (Sweden)

    John Wantania

    2013-08-01

    Full Text Available BACKGROUND: Preeclampsia is still a significant problem worldwide. Of the many suggested mechanisms of its pathogenesis, the latest one is the balance of angiogenic factor and its relationship with hypoxia factors. The objective of this study was to observe changes or dynamic process of soluble fms-like tyrosine kinase 1 (sFlt1 as anti-angiogenic factor and hypoxia inducible factor 1-alpha (HIF-1α as hypoxia marker in normotensive pregnancy and preeclampsia in mid-term and full-term pregnancies. METHODS: A cohort study was conducted on 36 normotensive subjects, first examination was conducted at 20-28 weeks of gestation. Then second examination was conducted at the time of preeclampsia diagnosed or full-term pregnancy. Preeclampsia was characterized by hypertension of systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, with two readings separated in 4-6 hours period, and/or proteinuria with urine dipstick of ≥1+ or ≥300 mg per 24 hours. Examinations of sFlt-1 and HIF-1α were done by enzyme-linked immunosorbent assay method. Statistical analysis was done using a significance level of p<0.05. RESULTS: Concentration of sFlt-1 was elevated in normotensive pregnancy and preeclampsia. Higher sFlt-1 concentration elevation was seen in preeclamptic group comparing to normotensive group, although not significant. This finding was related to the fact that investigated subjects were mostly developing mild preeclampsia merely. Comparing to normotensive group, preeclamptic group had higher HIF-1α concentration-per-week elevation, but not significant. There was a positive correlation between concentrations of sFlt-1 and HIF-1α, but not significant. CONCLUSIONS: sFlt-1 concentration elevation was correlated with preeclampsia. Therefore comparing to averages, changes of sFlt-1 concentrations were more important. Concentrations of HIF-1α and sFlt-1 were positively correlated. KEYWORDS: sFlt-1, HIF-1α, preeclampsia, normotension.

  19. Soluble fms-like tyrosine kinase-1 and endothelial adhesion molecules (intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1) as predictive markers for blood pressure reduction after renal sympathetic denervation.

    Science.gov (United States)

    Dörr, Oliver; Liebetrau, Christoph; Möllmann, Helge; Gaede, Luise; Troidl, Christian; Rixe, Johannes; Hamm, Christian; Nef, Holger

    2014-05-01

    Renal sympathetic denervation (RSD) is a treatment option for patients with resistant arterial hypertension, but in some patients it is not successful. Predictive parameters on the success of RSD remain unknown. The angiogenic factors soluble fms-like tyrosine kinase-1 (sFLT-1), intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) are known to be associated with endothelial dysfunction, vascular remodeling, and hypertension. We evaluated whether sFLT-1, ICAM-1, and VCAM-1 are predictive markers for blood pressure reduction after RSD. Consecutive patients (n=55) undergoing renal denervation were included. Venous serum samples for measurement of sFlt-1, ICAM-1, and VCAM-1 were collected before and 6 months after RSD. A therapeutic response was defined as an office systolic blood pressure reduction of >10 mm Hg 6 months after RSD. A significant mean office systolic blood pressure reduction of 31.2 mm Hg was observed in 46 patients 6 months after RSD. Nine patients were classified as nonresponders, with a mean systolic blood pressure reduction of 4.6 mm Hg. At baseline, sFLT-1 levels were significantly higher in responders than in nonresponders (P<0.001) as were ICAM-1 (P<0.001) and VCAM-1 levels (P<0.01). The areas under the curve for sFLT-1, ICAM-1, and VCAM-1 were 0.82 (interquartile range, 0.718-0.921; P<0.001), 0.754 (0.654-0.854; P<0.001), and 0.684 (0.564-804; P=0.01), respectively, demonstrating prediction of an RSD response. Responders showed significantly higher serum levels of sFLT-1, ICAM-1, and VCAM-1 at baseline compared with nonresponders. Thus, this study identified for the first time potential biomarkers with a predictive value indicating a responder or nonresponder before renal denervation. PMID:24470464

  20. Drug Discovery against Psoriasis: Identification of a New Potent FMS-like Tyrosine Kinase 3 (FLT3) Inhibitor, 1-(4-((1H-Pyrazolo[3,4-d]pyrimidin-4-yl)oxy)-3-fluorophenyl)-3-(5-(tert-butyl)isoxazol-3-yl)urea, That Showed Potent Activity in a Psoriatic Animal Model.

    Science.gov (United States)

    Li, Guo-Bo; Ma, Shuang; Yang, Ling-Ling; Ji, Sen; Fang, Zhen; Zhang, Guo; Wang, Li-Jiao; Zhong, Jie-Min; Xiong, Yu; Wang, Jiang-Hong; Huang, Shen-Zhen; Li, Lin-Li; Xiang, Rong; Niu, Dawen; Chen, Ying-Chun; Yang, Sheng-Yong

    2016-09-22

    Psoriasis is a chronic T-cell-mediated autoimmune disease, and FMS-like tyrosine kinase 3 (FLT3) has been considered as a potential molecular target for the treatment of psoriasis. In this investigation, structural optimization was performed on a lead compound, 1-(4-(1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)phenyl)-3-(4-chloro-3-(trifluoromethyl)phenyl)urea (1), which showed a moderate inhibitory activity againt FLT3. A series of pyrazolo[3,4-d]pyrimidine derivatives were synthesized, and structure-activity relationship analysis led to the discovery of a number of potent FLT3 inhibitors. One of the most active compounds, 1-(4-(1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-3-fluorophenyl)-3-(5-tert-butylisoxazol-3-yl)urea (18b), was then chosen for in-depth antipsoriasis studies because this compound displayed the highest potency in a preliminary antipsoriasis test. Compound 18b exhibited significant antipsoriatic effects in the K14-VEGF transgenic mouse model of psoriasis, and no recurrence was found 15 days later after the last administration. Detailed mechanisms of action of compound 18b were also investigated. Collectively, compound 18b could be a potential drug candidate for psoriasis treatment.

  1. 补肾安胎冲剂对复发性流产患者血清血管内皮生长因子及其可溶性受体-1的影响%Effects of Granules for Tonifying Kidney and Preventing Miscarriage on Serum Levels of Vascular Endothelial Growth Factor and Soluble Fms-like Tyrosine Kinase-1 in Patients with Recurrent Spontaneous Abortion

    Institute of Scientific and Technical Information of China (English)

    李伟莉; 胡瑞华

    2013-01-01

    目的 探讨补肾安胎冲剂治疗复发性流产(recurrent spontaneous abortion,RSA)的机制.方法 采用酶联免疫吸附法检测30例RSA患者治疗前后及30例正常早孕妇女血清血管内皮生长因子(vascular endothelial growth factor,VEGF)及其受体--可溶性fms样酪氨酸激酶-1(soluble fms-like tyrosine kinase-1,sFlt-1)的水平.结果 治疗组妊娠成功率为80.0%;与对照组比较,治疗组治疗前血清VEGF显著降低(P<0.01),sFlt-1显著增高(P<0.01);治疗组治疗后与治疗前比较,VEGF显著升高(P<0.01),sFlt-1显著降低(P<0.01);保胎治疗无效者与保胎治疗成功者比较,血清VEGF水平显著降低(P<0.01),血清sFlt-1水平显著增高(P<0.05).结论 补肾安胎冲剂治疗RSA的机制可能与提高血清VEGF水平,降低血清sFlt-1水平,从而促进胎盘绒毛血管的形成有关.%Objective To investigate the mechanism by -which Granules for tonifying the kidney and preventing miscarriage exert therapeutic effect in patients with recurrent spontaneous abortion (RSA). Methods Thirty RSA patients (as treatment group) and 30 women with normal early pregnancy (as control group) were included in this study. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) before and after treatment with the granules for tonifying the kidney and preventing miscarriage. Results The success rate of pregnancy was 80. 00% in the treatment group. Before treatment, the treatment group had significantly lower serum VEGF level and significantly higher serum sFlt-1 level than the control group (P

  2. Diagnosis of preeclampsia with soluble Fms-like tyrosine kinase 1/placental growth factor ratio

    DEFF Research Database (Denmark)

    Andersen, Louise Bjørkholt; Frederiksen-Møller, Britta; Work Havelund, Kathrine;

    2015-01-01

    women (n = 39) were included shortly after the time of diagnosis. Normotensive control pregnancies were matched by gestational age (n = 76). The KRYPTOR assays performed comparably or superior to Elecsys (sFlt-1/PlGF area under the curve 0.746 versus 0.735; P = .09; for non-obese 0.820 versus 0.805, P...... (HELLP) syndrome, the KRYPTOR sFlt-1/PlGF ratio was manifold increased (P obese women....

  3. Diagnosis of preeclampsia with soluble Fms-like tyrosine kinase 1/placental growth factor ratio: an inter-assay comparison.

    Science.gov (United States)

    Andersen, Louise Bjørkholt; Frederiksen-Møller, Britta; Work Havelund, Kathrine; Dechend, Ralf; Jørgensen, Jan Stener; Jensen, Boye L; Nielsen, Jan; Lykkedegn, Sine; Barington, Torben; Christesen, Henrik Thybo

    2015-02-01

    The angiogenic factor ratio soluble Fms-kinase 1 (sFlt-1)/placental growth factor (PlGF) is a novel diagnostic tool for preeclampsia. We compared the efficacy of the KRYPTOR (BRAHMS) automated assays for sFlt-1 and PlGF with the Elecsys (Roche) assays in a routine clinical setting. Preeclamptic women (n = 39) were included shortly after the time of diagnosis. Normotensive control pregnancies were matched by gestational age (n = 76). The KRYPTOR assays performed comparably or superior to Elecsys (sFlt-1/PlGF area under the curve 0.746 versus 0.735; P = .09; for non-obese 0.820 versus 0.805, P = .047). For early-onset preeclampsia, KRYPTOR area under the curve increased to 0.929 with a 100% specificity for preeclampsia at cut-off 85 and an 88.9% sensitivity for preeclampsia at cut-off 33. For women with preeclampsia and preterm delivery or Hemolysis, Elevated Liver enzymes, Low Platelet count (HELLP) syndrome, the KRYPTOR sFlt-1/PlGF ratio was manifold increased (P < .01). The sFlt-1/PlGF ratio proved especially useful in early-onset preeclampsia, preeclampsia with preterm delivery or HELLP, and among non-obese women.

  4. Activation of Fms-like tyrosine kinase 3 signaling enhances survivin expression in a mouse model of rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Sofia E M Andersson

    Full Text Available Survivin is known as an inhibitor of apoptosis and a positive regulator of cell division. We have recently identified survivin as a predictor of joint destruction in patients with rheumatoid arthritis (RA. Flt3 ligand (Flt3L is expressed in the inflamed joints and has adjuvant properties in arthritis. Studies on 90 RA patients (median age 60.5 years [range, 24-87], disease duration 10.5 years [range, 0-35] show a strong positive association between the levels of survivin and Flt3L in blood. Here, we present experimental evidence connecting survivin and Flt3L signaling. Treatment of BALB/c mice with Flt3L led to an increase of survivin in the bone marrow and in splenic dendritic cells. Flt3L changed the profile of survivin splice variants, increasing transcription of the short survivin40 in the bone marrow. Treatment with an Flt3 inhibitor reduced total survivin expression in bone marrow and in the dendritic cell population in spleen. Inhibition of survivin transcription in mice, by shRNA lentiviral constructs, reduced the gene expression of Flt3L. We conclude that expression of survivin is a downstream event of Flt3 signaling, which serves as an essential mechanism supporting survival of leukocytes during their differentiation, and maturation of dendritic cells, in RA.

  5. Preferred axis in cosmology

    CERN Document Server

    Zhao, Wen

    2016-01-01

    The foundation of modern cosmology relies on the so-called cosmological principle which states an homogeneous and isotropic distribution of matter in the universe on large scales. However, recent observations, such as the temperature anisotropy of the cosmic microwave background (CMB) radiation, the motion of galaxies in the universe, the polarization of quasars and the acceleration of the cosmic expansion, indicate preferred directions in the sky. If these directions have a cosmological origin, the cosmological principle would be violated, and modern cosmology should be reconsidered. In this paper, by considering the preferred axis in the CMB parity violation, we find that it coincides with the preferred axes in CMB quadrupole and CMB octopole, and they all align with the direction of the CMB kinematic dipole. In addition, the preferred directions in the velocity flows, quasar alignment, anisotropy of the cosmic acceleration, the handedness of spiral galaxies, and the angular distribution of the fine-structu...

  6. Vertical axis wind turbine airfoil

    Science.gov (United States)

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  7. Gut Microbiota-brain Axis

    Science.gov (United States)

    Wang, Hong-Xing; Wang, Yu-Ping

    2016-01-01

    Objective: To systematically review the updated information about the gut microbiota-brain axis. Data Sources: All articles about gut microbiota-brain axis published up to July 18, 2016, were identified through a literature search on PubMed, ScienceDirect, and Web of Science, with the keywords of “gut microbiota”, “gut-brain axis”, and “neuroscience”. Study Selection: All relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed, with no limitation of study design. Results: It is well-recognized that gut microbiota affects the brain's physiological, behavioral, and cognitive functions although its precise mechanism has not yet been fully understood. Gut microbiota-brain axis may include gut microbiota and their metabolic products, enteric nervous system, sympathetic and parasympathetic branches within the autonomic nervous system, neural-immune system, neuroendocrine system, and central nervous system. Moreover, there may be five communication routes between gut microbiota and brain, including the gut-brain's neural network, neuroendocrine-hypothalamic-pituitary-adrenal axis, gut immune system, some neurotransmitters and neural regulators synthesized by gut bacteria, and barrier paths including intestinal mucosal barrier and blood-brain barrier. The microbiome is used to define the composition and functional characteristics of gut microbiota, and metagenomics is an appropriate technique to characterize gut microbiota. Conclusions: Gut microbiota-brain axis refers to a bidirectional information network between the gut microbiota and the brain, which may provide a new way to protect the brain in the near future. PMID:27647198

  8. Fetal and Neonatal HPA Axis.

    Science.gov (United States)

    Wood, Charles E; Walker, Claire-Dominique

    2015-01-01

    Stress is an integral part of life. Activation of the hypothalamus-pituitary-adrenal (HPA) axis in the adult can be viewed as mostly adaptive to restore homeostasis in the short term. When stress occurs during development, and specifically during periods of vulnerability in maturing systems, it can significantly reprogram function, leading to pathologies in the adult. Thus, it is critical to understand how the HPA axis is regulated during developmental periods and what are the factors contributing to shape its activity and reactivity to environmental stressors. The HPA axis is not a passive system. It can actively participate in critical physiological regulation, inducing parturition in the sheep for instance or being a center stage actor in the preparation of the fetus to aerobic life (lung maturation). It is also a major player in orchestrating mental function, metabolic, and cardiovascular function often reprogrammed by stressors even prior to conception through epigenetic modifications of gametes. In this review, we review the ontogeny of the HPA axis with an emphasis on two species that have been widely studied-sheep and rodents-because they each share many similar regulatory mechanism applicable to our understanding of the human HPA axis. The studies discussed in this review should ultimately inform us about windows of susceptibility in the developing brain and the crucial importance of early preconception, prenatal, and postnatal interventions designed to improve parental competence and offspring outcome. Only through informed studies will our public health system be able to curb the expansion of many stress-related or stress-induced pathologies and forge a better future for upcoming generations.

  9. Vertical axis wind turbine acoustics

    OpenAIRE

    Pearson, Charlie

    2014-01-01

    Increasing awareness of the issues of climate change and sustainable energy use has led to growing levels of interest in small-scale, decentralised power generation. Small-scale wind power has seen significant growth in the last ten years, partly due to the political support for renewable energy and the introduction of Feed In Tariffs, which pay home owners for generating their own electricity. Due to their ability to respond quickly to changing wind conditions, small-scale vertical axis...

  10. ScaphoLunate Axis Method.

    Science.gov (United States)

    Yao, Jeffrey; Zlotolow, Dan A; Lee, Steve K

    2016-03-01

    Background Treating chronic scapholunate ligament injuries without the presence of arthritis remains an unsolved clinical problem facing wrist surgeons. This article highlights a technique for reconstructing the scapholunate ligament using novel fixation, the ScaphoLunate Axis Method (SLAM). Materials and Methods In a preliminary review of the early experience of this technique, 13 patients were evaluated following scapholunate ligament reconstruction utilizing the SLAM technique. Description of Techinque The scapholunate interval is reconstructed utilizing a palmaris longus autograft passed between the scaphoid and lunate along the axis of rotation in the sagittal plane. It is secured in the lunate using a graft anchor and in the scaphoid utilizing an interference screw. The remaining graft is passed dorsally to reconstruct the dorsal scapholunate ligament. Results At an average follow-up of 11 months, the mean postoperative scapholunate gap was 2.1 mm. The mean postoperative scapholunate angle was 59 degrees. The mean postoperative wrist flexion and extension was 45 and 56 degrees, respectively. The mean grip strength was 24.9 kg, or 62% of the contralateral side. The mean pain score (VAS) was 1.7. There was 1 failure with recurrence of the pathologic scapholunate gap and the onset of pain. Conclusion While chronic scapholunate ligament instability remains an unsolved problem facing wrist surgeons, newer techniques are directed toward restoring the normal relationships of the scaphoid and lunate in both the coronal and sagittal planes. The SLAM technique has demonstrated promise in preliminary clinical studies. PMID:26855838

  11. Principles of the prolactin/vasoinhibin axis.

    Science.gov (United States)

    Triebel, Jakob; Bertsch, Thomas; Bollheimer, Cornelius; Rios-Barrera, Daniel; Pearce, Christy F; Hüfner, Michael; Martínez de la Escalera, Gonzalo; Clapp, Carmen

    2015-11-15

    The hormonal family of vasoinhibins, which derive from the anterior pituitary hormone prolactin, are known for their inhibiting effects on blood vessel growth, vasopermeability, and vasodilation. As pleiotropic hormones, vasoinhibins act in multiple target organs and tissues. The generation, secretion, and regulation of vasoinhibins are embedded into the organizational principle of an axis, which integrates the hypothalamus, the pituitary, and the target tissue microenvironment. This axis is designated as the prolactin/vasoinhibin axis. Disturbances of the prolactin/vasoinhibin axis are associated with the pathogenesis of retinal and cardiac diseases and with diseases occurring during pregnancy. New phylogenetical, physiological, and clinical implications are discussed.

  12. An Elevated Maternal Plasma Soluble fms-Like Tyrosine Kinase-1 to Placental Growth Factor Ratio at Midtrimester Is a Useful Predictor for Preeclampsia

    Directory of Open Access Journals (Sweden)

    Mahmoud Fathy Hassan

    2013-01-01

    Full Text Available Background. To assess the ability of mid-trimester sFlt-1/PlGF ratio for prediction of preeclampsia in two different Arabic populations. Methods. This study measured levels of sFlt-1, PlGF, and sFlt-1/PlGF ratio at midtrimester in 83 patients who developed preeclampsia with contemporary 250 matched controls. Results. Women subsequently developed preeclampsia had significantly lower PlGF levels and higher sFlt-1 and sFlt-1/PlGF ratio levels than women with normal pregnancies (P<0.0001 for all. Women who with preterm preeclampsia had significantly higher sFlt-1 and sFlt-1/PlGF ratio than term preeclamptic women (P=0.01, 0.003, resp.. A cutoff value of 3198 pg/mL for sFlt-1 was able to predict preeclampsia with sensitivity, specificity, and accuracy of 88%, 83.6%, and 84.7%, respectively, with odds ratio (OR 37.2 [95% confidence interval (CI 17.7–78.1]. PIGF at cutoff value of 138 pg/mL was able to predict preeclampsia with sensitivity, specificity, and accuracy of 85.5%, 77.2%, and 79.3%, respectively, with OR 20 [95% CI, 10.2–39.5]. The sFlt-1/PIGF ratio at cutoff value of 24.5 was able to predict preeclampsia with sensitivity, specificity, and accuracy of 91.6%, 86.4%, and 87.7%, respectively with OR 67 [95% CI, 29.3–162.1]. Conclusion. Midtrimester sFlt-1/PlGF ratio displayed the highest sensitivity, specificity, accuracy, and OR for prediction of preeclampsia, demonstrating that it may stipulate more effective prediction of preeclampsia development than individual factor assay.

  13. Placental Growth Factor, Soluble fms-Like Tyrosine Kinase 1, Soluble Endoglin, IL-6, and IL-16 as Biomarkers in Preeclampsia

    Science.gov (United States)

    Rădulescu, Carmen; Huțanu, Adina; Gabor, Rozalia; Dobreanu, Minodora

    2016-01-01

    Preeclampsia (PE), an important cause of maternal and perinatal morbidity and mortality worldwide, is a pregnancy-related disease characterized by hypertension and proteinuria after 20 weeks of gestation. The aim of our study was to find a practical panel of biomarkers useful in early diagnosis of PE. This study was carried out at the Obstetrics and Gynecology Department in Tîrgu Mureș University Hospital, Romania, between January 2014 and July 2015 and included 68 pregnant women (47 preeclamptic women and 21 controls) with gestational age between 16 and 20 weeks at enrollment. The biomarkers PlGF, sFlt-1, sEng, IL-6, and IL-16 were determined by ELISA test. We compared the serum levels of soluble markers analysed in preeclamptic women and controls during the second and third trimesters of pregnancy and we found that the best predictor for PE was PlGF with a sensitivity of 100% at a concentration threshold of 120.16 pg/mL, a diagnosis accuracy of 70.8%, and AUC of 0.684 (p = 0.005). We also estimated the risk for PE according to BMI and we found that pregnant women with weight >90 kg had 7 times higher risk for PE. Second-trimester PlGF serum level may serve as an early biomarker for the diagnosis of PE.

  14. Discovery and Rational Design of Pteridin-7(8H)-one-Based Inhibitors Targeting FMS-like Tyrosine Kinase 3 (FLT3) and Its Mutants.

    Science.gov (United States)

    Sun, Deheng; Yang, Yu; Lyu, Jiankun; Zhou, Wei; Song, Wenlin; Zhao, Zhenjiang; Chen, Zhuo; Xu, Yufang; Li, Honglin

    2016-07-14

    FLT3 has been validated as a therapeutic target for the treatment of acute myeloid leukemia (AML). In this paper, we describe for the first time, pteridin-7(8H)-one as a scaffold for potent FLT3 inhibitors derived from structural optimizations on irreversible EGFR inhibitors. The representative inhibitor (31) demonstrates single-digit nanomolar inhibition against FLT3 and subnanomolar KD for drug-resistance FLT3 mutants. In profiling of the in vitro tumor cell lines, it shows good selectivity against AML cells harboring FLT3-ITD mutations over other leukemia and solid tumor cell lines. The mechanism of action study illustrates that pteridin-7(8H)-one derivatives suppress the phosphorylation of FLT3 and its downstream pathways, thereby inducing G0/G1 cell cycle arrest and apoptosis in AML cells. In in vivo studies, 31 significantly suppresses the tumor growth in MV4-11 xenograft model. Overall, we provide a structurally distinct chemical scaffold with which to develop FLT3 mutants-selective inhibitors for AML treatment.

  15. Introductory lecture on triple-axis spectrometer

    International Nuclear Information System (INIS)

    Triple-axis spectrometer is a multi-purpose instrument for powder neutron diffraction, single crystal neutron diffraction, powder inelastic neutron scattering, single crystal inelastic neutron scattering, and neutron polarization analysis. In this lecture how to use the triple-axis spectrometer is explained for the beginners. (author)

  16. Identification of Kinematic Errors of Five-axis Machine Tool Trunnion Axis from Finished Test Piece

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya; FU Jianzhong; CHEN Zichen

    2014-01-01

    Compared with the traditional non-cutting measurement, machining tests can more accurately reflect the kinematic errors of five-axis machine tools in the actual machining process for the users. However, measurement and calculation of the machining tests in the literature are quite difficult and time-consuming. A new method of the machining tests for the trunnion axis of five-axis machine tool is proposed. Firstly, a simple mathematical model of the cradle-type five-axis machine tool was established by optimizing the coordinate system settings based on robot kinematics. Then, the machining tests based on error-sensitive directions were proposed to identify the kinematic errors of the trunnion axis of cradle-type five-axis machine tool. By adopting the error-sensitive vectors in the matrix calculation, the functional relationship equations between the machining errors of the test piece in the error-sensitive directions and the kinematic errors of C-axis and A-axis of five-axis machine tool rotary table was established based on the model of the kinematic errors. According to our previous work, the kinematic errors of C-axis can be treated as the known quantities, and the kinematic errors of A-axis can be obtained from the equations. This method was tested in Mikron UCP600 vertical machining center. The machining errors in the error-sensitive directions can be obtained by CMM inspection from the finished test piece to identify the kinematic errors of five-axis machine tool trunnion axis. Experimental results demonstrated that the proposed method can reduce the complexity, cost, and the time consumed substantially, and has a wider applicability. This paper proposes a new method of the machining tests for the trunnion axis of five-axis machine tool.

  17. Axis intersection measurement of three-axis turntable with two crosshair targets

    Institute of Scientific and Technical Information of China (English)

    REN Shun-qing; MA Guang-cheng; WANG Chang-hong

    2005-01-01

    In order to measure three-axis intersection error, two crosshair targets were fixed in the inner axis frame of a three-axis turntable. Also a theodolite was used to point its telescope to the targets and to measure the horizontal angles when three axes were on equi-spaced angle positions. The calculation equations of the axis intersection were deduced from the mounting position of the theodolite, positions of two targets, angular positions of three axes, and the measured horizontal angles with the theodolite. Finally, a practical measurement is carried out on a horizontal three-axis turntable and error analysis is conducted.

  18. Axis of Zodiacal light Near Tropic Cancer

    CERN Document Server

    Nawar, S; Mikhail, J S; Morcos, A B; Ibrahim, Alhassan I

    2014-01-01

    The axis of zodiacal lights have been obtained in blue and yellow colors using photoelectric observations of zodiacal light. These observations have been carried out at Abu Simbel Site in Egypt, in October 1975. This site lies too near to the tropic of Cancer, at which the axis of the zodiacal light cone perpendiculars to the horizon. The results show that the plane of the zodiacal light is inclined to the normal by 1.59 degrees in blue color and 1.18 degrees in yellow color. This means that there is a slight variation in zodiacal light axis with wavelength, and the axis almost coincide with the ecliptic. The present results for blue color can be considered as the first one in the world near the tropic of Cancer.

  19. Multi-axis integrated Hall magnetic sensors

    Directory of Open Access Journals (Sweden)

    Popović Radivoje S.

    2007-01-01

    Full Text Available Conventional Hall magnetic sensors respond only to the magnetic field component perpendicular to the surface of the sensor die. Multi-axis sensing capability can be provided in the following two ways: (a by integrating magnetic flux concentrators on the die, and (b by using vertical Hall devices. Here we review the most important two-and three-axis integrated Hall magnetic sensors based on these concepts. Their applications include mapping of magnetic fields and sensing angular position.

  20. Sex differences in the HPA axis.

    Science.gov (United States)

    Goel, Nirupa; Workman, Joanna L; Lee, Tiffany T; Innala, Leyla; Viau, Victor

    2014-07-01

    The hypothalamic-pituitary-adrenal (HPA) axis is a major component of the systems that respond to stress, by coordinating the neuroendocrine and autonomic responses. Tightly controlled regulation of HPA responses is critical for maintaining mental and physical health, as hyper- and hypo-activity have been linked to disease states. A long history of research has revealed sex differences in numerous components of the HPA stress system and its responses, which may partially form the basis for sex disparities in disease development. Despite this, many studies use male subjects exclusively, while fewer reports involve females or provide direct sex comparisons. The purpose of this article is to present sex comparisons in the functional and molecular aspects of the HPA axis, through various phases of activity, including basal, acute stress, and chronic stress conditions. The HPA axis in females initiates more rapidly and produces a greater output of stress hormones. This review focuses on the interactions between the gonadal hormone system and the HPA axis as the key mediators of these sex differences, whereby androgens increase and estrogens decrease HPA activity in adulthood. In addition to the effects of gonadal hormones on the adult response, morphological impacts of hormone exposure during development are also involved in mediating sex differences. Additional systems impinging on the HPA axis that contribute to sex differences include the monoamine neurotransmitters norepinephrine and serotonin. Diverse signals originating from the brain and periphery are integrated to determine the level of HPA axis activity, and these signals are, in many cases, sex-specific.

  1. UMAPRM: Uniformly sampling the medial axis

    KAUST Repository

    Yeh, Hsin-Yi Cindy

    2014-05-01

    © 2014 IEEE. Maintaining clearance, or distance from obstacles, is a vital component of successful motion planning algorithms. Maintaining high clearance often creates safer paths for robots. Contemporary sampling-based planning algorithms That utilize The medial axis, or The set of all points equidistant To Two or more obstacles, produce higher clearance paths. However, They are biased heavily Toward certain portions of The medial axis, sometimes ignoring parts critical To planning, e.g., specific Types of narrow passages. We introduce Uniform Medial Axis Probabilistic RoadMap (UMAPRM), a novel planning variant That generates samples uniformly on The medial axis of The free portion of Cspace. We Theoretically analyze The distribution generated by UMAPRM and show its uniformity. Our results show That UMAPRM\\'s distribution of samples along The medial axis is not only uniform but also preferable To other medial axis samplers in certain planning problems. We demonstrate That UMAPRM has negligible computational overhead over other sampling Techniques and can solve problems The others could not, e.g., a bug Trap. Finally, we demonstrate UMAPRM successfully generates higher clearance paths in The examples.

  2. Actuator assembly including a single axis of rotation locking member

    Science.gov (United States)

    Quitmeyer, James N.; Benson, Dwayne M.; Geck, Kellan P.

    2009-12-08

    An actuator assembly including an actuator housing assembly and a single axis of rotation locking member fixedly attached to a portion of the actuator housing assembly and an external mounting structure. The single axis of rotation locking member restricting rotational movement of the actuator housing assembly about at least one axis. The single axis of rotation locking member is coupled at a first end to the actuator housing assembly about a Y axis and at a 90.degree. angle to an X and Z axis providing rotation of the actuator housing assembly about the Y axis. The single axis of rotation locking member is coupled at a second end to a mounting structure, and more particularly a mounting pin, about an X axis and at a 90.degree. angle to a Y and Z axis providing rotation of the actuator housing assembly about the X axis. The actuator assembly is thereby restricted from rotation about the Z axis.

  3. [Leptin and hypothalamus-hypophysis-thyroid axis].

    Science.gov (United States)

    Riccioni, G; Menna, V; Lambo, M S; Della Vecchia, R; Di Ilio, C; De Lorenzo, A; D'Orazio, N

    2004-01-01

    The leptin system is a major regulator of food intake and metabolic rate. The leptin, an adipose tissue hormone whose plasma levels reflect energy stores, plays an important rule in the pathogenesis of such eating disorders like bulimia and anorexia. Thyroid hormones are major regulators of energy homeostasis. It is possible that leptin and thyroid hormone exert their actions on thermogenesis and energy metabolism via the same common effector patways. Leptin influences feedback regulation of the hypotalamic TRH-secreting neurons by thyroid hormone. Low serum levels of thyroid hormones reflect a dysfunction of the hypotalamic-pituitary-thyroid (HPT) and hypotalamic-pituitary-adrenal (HPA) axis in patients with nervosa anorexia. Neuroendocrine effects of leptin include effects on the HPT and HPA axis. The aim of this work is to evaluated the interactions between leptina and HPT axis on the basis of recent published works and reviews in literature. PMID:15147079

  4. Diffuser Augmented Horizontal Axis Tidal Current Turbines

    Directory of Open Access Journals (Sweden)

    Nasir Mehmood

    2012-09-01

    Full Text Available The renewal energy technologies are increasingly popular to ensure future energy sustenance and address environmental issues. The tides are enormous and consistent untapped resource of renewable energy. The growing interest in exploring tidal energy has compelling reasons such as security and diversity of supply, intermittent but predictable and limited social and environmental impacts. The tidal energy industry is undergoing an increasing shift towards diffuser augmented turbines. The reason is the higher power output of diffuser augmented turbines compared to conventional open turbines. The purpose of this study is to present a comprehensive review of diffuser augmented horizontal axis tidal current turbines. The components, relative advantages, limitations and design parameters of diffuser augmented horizontal axis tidal current turbines are presented in detail. CFD simulation of NACA 0016 airfoil is carried out to explore its potential for designing a diffuser. The core issues associated with diffuser augmented horizontal axis tidal current turbines are also discussed.

  5. New Urban Vertical Axis Wind Turbine Design

    Directory of Open Access Journals (Sweden)

    Alexandru-Mihai CISMILIANU

    2015-12-01

    Full Text Available This paper develops a different approach for enhancing the performance of Vertical Axis Wind Turbines for the use in the urban or rural environment and remote isolated residential areas. Recently the vertical axis wind turbines (VAWT have become more attractive due to the major advantages of this type of turbines in comparison to the horizontal axis wind turbines. We aim to enhance the overall performance of the VAWT by adding a second set of blades (3 x 2=6 blades following the rules of biplane airplanes. The model has been made to operate at a maximum power in the range of the TSR between 2 to 2.5. The performances of the VAWT were investigated numerically and experimentally and justify the new proposed design.

  6. Solar rotating magnetic dipole?. [around axis perpendicular to rotation axis of the sun

    Science.gov (United States)

    Antonucci, E.

    1974-01-01

    A magnetic dipole rotating around an axis perpendicular to the rotation axis of the sun can account for the characteristics of the surface large-scale solar magnetic fields through the solar cycle. The polarity patterns of the interplanetary magnetic field, predictable from this model, agree with the observed interplanetary magnetic sector structure.

  7. DRIVE AND CONTROL OF VIRTUAL-AXIS NC MACHINE TOOLS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The structure features and driving modes of virtual-axis NC machine tools are studied.Accor- ding to different application requirements,the three-axis control method,the five-axis control method and the six-freedom control method are put forward.These results lay a foundation for the product development of the virtual-axis NC machine tools.

  8. Triple-axis spectrometer DruechaL

    Energy Technology Data Exchange (ETDEWEB)

    Buehrer, W.; Keller, P. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    DruechaL is a triple-axis spectrometer located at a cold guide. The characteristics of guide and instrument allow the use of a broad spectral range of neutrons. The resolution in momentum and energy transfer can be tuned to match the experimental requirements by using either collimators or focusing systems (monochromator, antitrumpet, analyser). (author) figs., tabs., refs.

  9. The Trading Axis in Irkutsk Downtown

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2015-12-01

    Full Text Available The article reveals a linear concentration of the trading function in the historical center of Irkutsk. It features historical prerequisites and continuation of the tradition in the post-Soviet period, given the conversion of plants and factories. The article analyses the current state and prospects of modernization of the trading axis with its transformation into a modern public space.

  10. Fibrous dysplasia in axis treated with vertebroplasty

    Directory of Open Access Journals (Sweden)

    Kadir Kotil

    2010-01-01

    Full Text Available Vertebroplasty of the axis is a challenging procedure, and little is known about its therapeutic outcome. Cervical fibrous dysplasia with a distinct cyst is a rare entity and few cases have been reported in the literature. A 55-year-old man with fibrous dysplasia of axis presented with severe neck pain and left arm since six months. Computed tomography and magnetic resonance imaging revealed an expansile, destructive lesion involving the axis, and no spinal cord. He was submitted to retropharyngeal surgery and the lesion was fulled by vertebroplasty. Microscopic examination was consistent with the diagnosis of monostotic fibrous dysplasia. After the surgery no recurrence was observed. The patient had remarkable improvement in clinical relief of neck pain at 1-year follow-up. Although there are descriptions of vertebral fibrous dysplasia, this is the 13th case of monostotic fibrous dysplasia of the cervical spine, and the 3rd case of the axis described in the literature. The unique case who had treated with ope vertebroplasty.

  11. Resolution of a triple axis spectrometer

    DEFF Research Database (Denmark)

    Nielsen, Mourits; Bjerrum Møller, Hans

    1969-01-01

    A new method for obtaining the resolution function for a triple-axis neutron spectrometer is described, involving a combination of direct measurement and analytical calculation. All factors which contribute to the finite resolution of the instrument may be taken into account, and Gaussian...

  12. Horizontal Axis Levitron--A Physics Demonstration

    Science.gov (United States)

    Michaelis, Max M.

    2014-01-01

    After a brief history of the Levitron, the first horizontal axis Levitron is reported. Because it is easy to operate, it lends itself to educational physics experiments and analogies. Precession and nutation are visualized by reflecting the beam from a laser pointer off the "spignet". Precession is fundamental to nuclear magnetic…

  13. Tennis Rackets and the Parallel Axis Theorem

    Science.gov (United States)

    Christie, Derek

    2014-01-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  14. Multi-Axis Accelerometer Calibration System

    Science.gov (United States)

    Finley, Tom; Parker, Peter

    2010-01-01

    A low-cost, portable, and simplified system has been developed that is suitable for in-situ calibration and/or evaluation of multi-axis inertial measurement instruments. This system overcomes facility restrictions and maintains or improves the calibration quality for users of accelerometer-based instruments with applications in avionics, experimental wind tunnel research, and force balance calibration applications. The apparatus quickly and easily positions a multi-axis accelerometer system into a precisely known orientation suitable for in-situ quality checks and calibration. In addition, the system incorporates powerful and sophisticated statistical methods, known as response surface methodology and statistical quality control. These methods improve calibration quality, reduce calibration time, and allow for increased calibration frequency, which enables the monitoring of instrument stability over time.

  15. Turbulence in vertical axis wind turbine canopies

    OpenAIRE

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-01-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the i...

  16. Local Pancake Defeats Axis of Evil

    OpenAIRE

    Vale, Chris

    2005-01-01

    Among the biggest surprises revealed by COBE and confirmed by WMAP measurements of the temperature anisotropy of the CMB are the anomalous features in the 2-point angular correlation function on very large angular scales. In particular, the $\\ell = 2$ quadrupole and $\\ell = 3$ octopole terms are surprisingly planar and aligned with one another, which is highly unlikely for a statistically isotropic Gaussian random field, and the axis of the combined low-$\\ell$ signal is perpendicular to eclip...

  17. Cross-axis adaptation of torsional components in the yaw-axis vestibulo-ocular reflex

    Science.gov (United States)

    Trillenberg, P.; Shelhamer, M.; Roberts, D. C.; Zee, D. S.

    2003-01-01

    The three pairs of semicircular canals within the labyrinth are not perfectly aligned with the pulling directions of the six extraocular muscles. Therefore, for a given head movement, the vestibulo-ocular reflex (VOR) depends upon central neural mechanisms that couple the canals to the muscles with the appropriate functional gains in order to generate a response that rotates the eye the correct amount and around the correct axis. A consequence of these neural connections is a cross-axis adaptive capability, which can be stimulated experimentally when head rotation is around one axis and visual motion about another. From this visual-vestibular conflict the brain infers that the slow-phase eye movement is rotating around the wrong axis. We explored the capability of human cross-axis adaptation, using a short-term training paradigm, to determine if torsional eye movements could be elicited by yaw (horizontal) head rotation (where torsion is normally inappropriate). We applied yaw sinusoidal head rotation (+/-10 degrees, 0.33 Hz) and measured eye movement responses in the dark, and before and after adaptation. The adaptation paradigm lasted 45-60 min, and consisted of the identical head motion, coupled with a moving visual scene that required one of several types of eye movements: (1) torsion alone (-Roll); (2) horizontal/torsional, head right/CW torsion (Yaw-Roll); (3) horizontal/torsional, head right/CCW torsion (Yaw+Roll); (4) horizontal, vertical, torsional combined (Yaw+Pitch-Roll); and (5) horizontal and vertical together (Yaw+Pitch). The largest and most significant changes in torsional amplitude occurred in the Yaw-Roll and Yaw+Roll conditions. We conclude that short-term, cross-axis adaptation of torsion is possible but constrained by the complexity of the adaptation task: smaller torsional components are produced if more than one cross-coupling component is required. In contrast, vertical cross-axis components can be easily trained to occur with yaw head

  18. Micromachined dual input axis rate gyroscope

    Science.gov (United States)

    Juneau, Thor Nelson

    The need for inexpensive yet reliable angular rate sensors in fields ranging from automotive to consumer electronics has motivated prolific micromachined rate gyroscope research. The vast majority of research has focused on single input axis rate gyroscopes based upon either translational resonance, such as tuning forks, or structural mode resonance, such as vibrating rings. However, this work presents a novel, contrasting approach based on angular resonance of a rotating rigid rotor suspended by torsional springs. The inherent symmetry of the circular design allows angular rate measurement about two axes simultaneously, hence the name micromachined dual-axis rate gyroscope. The underlying theory of operation, mechanical structure design optimization, electrical interface circuitry, and signal processing are described in detail. Several operational versions were fabricated using two different fully integrated surface micromachining processes as proof of concept. The heart of the dual-axis rate gyroscope is a ˜2 mum thick polysilicon disk or rotor suspended above the substrate by a four beam suspension. When this rotor in driven into angular oscillation about the axis perpendicular to the substrate, a rotation rate about the two axes parallel to the substrate invokes an out of plane rotor tilting motion due to Coriolis acceleration. This tilting motion is capacitively measured and on board integrated signal processing provides two output voltages proportional to angular rate input about the two axes parallel to the substrate. The design process begins with the derivation of gyroscopic dynamics. The equations suggest that tuning sense mode frequencies to the drive oscillation frequency can vastly increase mechanical sensitivity. Hence the supporting four beam suspension is designed such that electrostatic tuning can match modes despite process variations. The electrostatic tuning range is limited only by rotor collapse to the substrate when tuning-voltage induced

  19. Pulsed 3-Axis Vector SERF Magnetometer

    Science.gov (United States)

    Hedges, Morgan; Romalis, Michael

    2016-05-01

    We demonstrate a 3-axis atomic vector magnetometer operating in the SERF regime, using a single beam path, and capable of operating in Earth's field using field feedback. It has similar sensitivity along all 3 axes that is fundamentally limited by photon and atom shot noise. The scheme uses a high intensity pump pulse to polarize Rb atoms in ~ 1 μs and a sequence of magnetic field pulses applied while the atoms are monitored during free precession. The sequence used provides minimal sensitivity to pulse errors, while also allowing unambiguous discrimination between external magnetic fields and misalignment between laser and magnetic coil axes.

  20. Optimisation of vertical axis wind turbines

    OpenAIRE

    Roynarin, Wirachai

    2004-01-01

    A practical Vertical Axis Wind Turbine (VAWTs) based on a Darrieus rotor has been designed and tested and found to be capable of self-starting at wind speeds above 4m/s. The self-start feature has been achieved by replacing the usual symmetrical aerofoil blade in the VAWT rotor and by using a concentric Savonius rotor or semi-cylinder turbine. A computer program was produced to compute the power coefficient versus tip speed ratio characteristics of a selected aerofoil profile employed in a VA...

  1. Horizontal axis Levitron—a physics demonstration

    Science.gov (United States)

    Michaelis, Max M.

    2014-01-01

    After a brief history of the Levitron, the first horizontal axis Levitron is reported. Because it is easy to operate, it lends itself to educational physics experiments and analogies. Precession and nutation are visualized by reflecting the beam from a laser pointer off the ‘spignet’. Precession is fundamental to nuclear magnetic resonance, magnetic resonance imaging, particle traps and the movement of bodies in space. Longitudinal and lateral bounce behaviour is explained via ‘the principle of gentle superposition’ of two traps: the micro-precessional and the macro-trap. Theory is initiated. Scaling experiments are mentioned. Industrial applications might follow. Patent pending.

  2. Equilibrium calculations for helical axis stellarators

    International Nuclear Information System (INIS)

    An average method based on a vacuum flux coordinate system is presented. This average method permits the study of helical axis stellarators with toroidally dominated shifts. An ordering is introduced, and to lowest order the toroidally averaged equilibrium equations are reduced to a Grad-Shafranov equation. Also, to lowest order, a Poisson-type equation is obtained for the toroidally varying corrections to the equilibium. By including these corrections, systems that are toroidally dominated, but with significant helical distortion to the equilibrium, may be studied. Numerical solutions of the average method equations are shown to agree well with three-dimensional calculations

  3. Single-axis gyroscopic motion with uncertain angular velocity about spin axis

    Science.gov (United States)

    Singh, S. N.

    1977-01-01

    A differential game approach is presented for studying the response of a gyro by treating the controlled angular velocity about the input axis as the evader, and the bounded but uncertain angular velocity about the spin axis as the pursuer. When the uncertain angular velocity about the spin axis desires to force the gyro to saturation a differential game problem with two terminal surfaces results, whereas when the evader desires to attain the equilibrium state the usual game with single terminal manifold arises. A barrier, delineating the capture zone (CZ) in which the gyro can attain saturation and the escape zone (EZ) in which the evader avoids saturation is obtained. The CZ is further delineated into two subregions such that the states in each subregion can be forced on a definite target manifold. The application of the game theoretic approach to Control Moment Gyro is briefly discussed.

  4. VERITAS: Versatile Triple-Axis Spectrometer

    International Nuclear Information System (INIS)

    Korea Atomic Energy Research Institute is planning to build a cold neutron triple-axis spectrometer at HANARO, the 30 MW research reactor. The spectrometer is expected to be completed in 2008 with the following configuration from the upstream to the downstream. Guide Supermirror m = 2, In-pile Straight Section, ∼ 5 m Curved Guide, ∼ 26 m w/ R 1500 m Straight Guide before the Instrument, ∼ 40 m Filters PG and Be Neutron Velocity Selector (Future) Monochromators Vertically Focusing Monochromators PG(002) and Heusler(111) Doubly Focusing Monochromators (Future) Monochromator-Sample Distance 2 m Collimation C1 Soller Collimators, 20', 40' 80'Beam Height at the Sample Table 1.5 m Sample-Analyzer Distance 1.0 m Collimation C2 Soller Collimators, 20', 40', 80' Radial Collimator Analyzers Horizontally Focusing Analyzers w/ Fixed Vertical Focusing PG(002) and Heusler(111) Analyzer-Detector Distance 0.5 m Detectors 5 cm Tube Detector 25 cm wide Position Sensitive Detector Once completed, the neutron flux at sample is expected to surpass that of SPINS at NCNR, making this instrument one of the most powerful 2nd generation cold neutron triple-axis spectrometers in the world

  5. VERITAS: Versatile Triple-Axis Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Il

    2006-04-15

    Korea Atomic Energy Research Institute is planning to build a cold neutron triple-axis spectrometer at HANARO, the 30 MW research reactor. The spectrometer is expected to be completed in 2008 with the following configuration from the upstream to the downstream. Guide Supermirror m = 2, In-pile Straight Section, {approx} 5 m Curved Guide, {approx} 26 m w/ R 1500 m Straight Guide before the Instrument, {approx} 40 m Filters PG and Be Neutron Velocity Selector (Future) Monochromators Vertically Focusing Monochromators PG(002) and Heusler(111) Doubly Focusing Monochromators (Future) Monochromator-Sample Distance 2 m Collimation C1 Soller Collimators, 20', 40' 80'Beam Height at the Sample Table 1.5 m Sample-Analyzer Distance 1.0 m Collimation C2 Soller Collimators, 20', 40', 80' Radial Collimator Analyzers Horizontally Focusing Analyzers w/ Fixed Vertical Focusing PG(002) and Heusler(111) Analyzer-Detector Distance 0.5 m Detectors 5 cm Tube Detector 25 cm wide Position Sensitive Detector Once completed, the neutron flux at sample is expected to surpass that of SPINS at NCNR, making this instrument one of the most powerful 2nd generation cold neutron triple-axis spectrometers in the world.

  6. Lift Augmentation for Vertical Axis Wind Turbines

    Directory of Open Access Journals (Sweden)

    Gerald M Angle II

    2010-12-01

    Full Text Available The concept of harnessing wind power has been around for centuries, and is first recorded by the Persians in 900 AD. These early uses of wind power were for the processing of food, particularly grinding grains, and consisted of stationary blades around a horizontal axis, the precursor to today’s horizontal axis wind turbines (HAWT. Technology for these wind mills was essentially the same until the 1930’s when advances in aircraft propeller theories were applied to the blades of the turbine. During this development period, which has since remained basically unchanged, the design push was for increasingly larger propellers requiring heavy and costly transmissions, generators, and support towers to be installed. An alternative concept to the HAWT was developed by Georges Darrieus [5], which utilized a vertical shaft and is known as a vertical axis wind turbine (VAWT. The scientific development of the concept did not gain strong attention until the 1970’s due to the perceived low efficiency of this style. This perception was due in part to the portion of the blade’s rotary path that is adverse to the generation of power. This efficiency loss can be minimized by the mechanical movement of the blade, relative to the airflow during the upwind portion of the blades’ rotational path. Since, circulation control can alter the forces generated by an airfoil, it could be used to increase the efficiency of a VAWT by increasing the torque produced on the downwind portion of the path, while removing the need for a physical change in angle of attack. With the recent upturn in petroleum costs and global warming concerns, interest in renewable energy technologies have been reinvigorated, in particular the desire for advanced wind energy technologies, including the application of lift augmentation techniques. One of these techniques is to utilize circulation control to enhance the lifting capacity of the blades based on the location of the blade in the

  7. Computer Assisted Mechanical Axis and Kinematic TKA

    Science.gov (United States)

    McEwen, Peter; Mahoharan, Varaguna

    2016-01-01

    Introduction: Total knee arthroplasty (TKA) has traditionally been and largely continues to be aligned mechanically, that being with a neutral coronal plane mechanical tibiofemoral axis and a joint line orientated at 900 to this axis. Femoral component rotation is set by gap balancing or by externally rotating 30 from any of a number femoral reference lines. This produces a rectangular flexion gap and relaxes patellar tracking. Kinematic alignment (KA) is an alternative technique that aims to restore premorbid alignment, joint orientation and ligament tension. The basic premise for this technique is based on evidence that the medial and lateral femoral condyles consistently equate to cylinders of equal or near equal size and that therefore with a fixed radius, cruciate retaining implant, matched distal femoral, posterior femoral and proximal tibial resections, accounting for bone and cartilage already lost will reproduce the premorbid joint line and restore native premorbid kinematics. Femoral rotation is therefore referenced off the prearthritic posterior condylar axis (PCA) that is on average internally rotated to the AP axis. Kinematic alignment therefore has the potential to challenge patellar tracking, increase patellar load and potentially increase patellar complications. Method: Case control study – level of evidence III-2. Between November 2012 and June 2013 the senior author completed 104 consecutive computer assisted (CAS) kinematically aligned total knee arthroplasties (TKA) with a cruciate retaining, fixed bearing, single radius implant. The results of these surgeries were compared with the results of 91 consecutive CAS mechanically aligned TKA done between November 2011 and October 2012 using the same navigation system and implant Implant sizing and positioning as well as gap measurement and ligament balance was done with computer assistance in all cases. Data was collected prospectively and analysed retrospectively. Results: The Oxford Knee Score

  8. Model for performance prediction in multi-axis machining

    CERN Document Server

    Lavernhe, Sylvain; Lartigue, Claire; 10.1007/s00170-007-1001-4

    2009-01-01

    This paper deals with a predictive model of kinematical performance in 5-axis milling within the context of High Speed Machining. Indeed, 5-axis high speed milling makes it possible to improve quality and productivity thanks to the degrees of freedom brought by the tool axis orientation. The tool axis orientation can be set efficiently in terms of productivity by considering kinematical constraints resulting from the set machine-tool/NC unit. Capacities of each axis as well as some NC unit functions can be expressed as limiting constraints. The proposed model relies on each axis displacement in the joint space of the machine-tool and predicts the most limiting axis for each trajectory segment. Thus, the calculation of the tool feedrate can be performed highlighting zones for which the programmed feedrate is not reached. This constitutes an indicator for trajectory optimization. The efficiency of the model is illustrated through examples. Finally, the model could be used for optimizing process planning.

  9. Polarized triple-axis spectrometer TASP

    Energy Technology Data Exchange (ETDEWEB)

    Boeni, P.; Keller, P. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    The polarized triple-axis spectrometer TASP at SINQ has been optimized for measuring magnetic cross sections in condensed matter. The neutrons are polarized or analyzed either by means of benders or Heusler monochromators. The beam divergence, i.e. the intensity, and the spectral range of the neutrons is rather large because of the supermirror coatings of the feeding neutron guide. The intensity can be further increased at the sample position by means of a focussing monochromator and a focussing anti-trumpet. The end position of TASP allows the tailoring of the neutron beam already before the monochromator and to scatter neutrons over very wide ranges of angles. (author) 6 figs., 1 tab., 8 refs.

  10. Five-axis rough machining for impellers

    Institute of Scientific and Technical Information of China (English)

    Ruolong QI; Weijun LIU; Hongyou BIAN; Lun LI

    2009-01-01

    The most important components used in aero-space, ships, and automobiles are designed with free form surfaces. An impeller is one of the most important components that is difficult to machine because of its twisted blades. Rough machining is recognized as the most crucial procedure influencing machining efficiency and is critical for the finishing process. An integrated rough machining course with detailed algorithms is presented in this paper. An algorithm for determining the minimum distance between two surfaces is applied to estimate the tool size. The space between two blades that will be cleared from the roughcast is divided to generate CC points. The tool axis vector is confirmed based on flank milling using a simple method that could eliminate global interference between the tool and the blades. The result proves that the machining methodology presented in this paper is useful and successful.

  11. A Portable Single Axis Magnetic Gradiometer

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Petersen, Jan Raagaard; Nielsen, Otto V;

    2001-01-01

    not provide vector information about the magnetic field. Secondly, one of the sensors measures the ambient magnetic field and is used to compensate for the main field at both sensors. Several methods have been developed for characterization of the 2 gradiometer, and the calibration of the gradient......The single axis magnetic gradiometer based on two compact detector compensation (CDC) fluxgate ringcore sensors separated 20 cm is described. Despite its high stability and precision better than 1 nT, the calibration procedures are not straightforward. Firstly, the mono-axial measurement does...... measurements is achieved by using a magnetic dipole of strength 2 mAm(2). In a coil facility, the gradient can be determined with an accuracy of 0.3 nT/m(RMS)....

  12. H3837 DARHT's first dual-axis shot

    International Nuclear Information System (INIS)

    Test H3837 was the first explosive shot performed in front of both flash x-ray axes at the Los Alamos Dual Axis Radiographic HydroTest (DARHT) facility. Executed in November 2009, the shot was an explosively-driven metal flyer plate in a series of experiments designed to explore equation-of-state properties of shocked materials. With high-strength steel walls over half an inch thick, the boom box confined the shot completely without taxing the penetrating capability of the DARHT x-ray beams; in addition, over three inches of tungsten attenuation in the beamlines prevented saturation of the camera systems. The boombox was staged within the DACS (Dual Axis Confinement system) with a source-to-object distance of 1.33 m for each Axis; radiographic magnifications were 4 and 4.5 for Axes I and II respectively. The first Axis provided a pulse of 60 ns width and dose 450 R at 1 m, while the second Axis provided four pulses of the following widths and doses: 20 ns, 85 R; 45 ns, 169 R; 65 ns, 233 R; 65 ns, 225 R; beam spot sizes were measured (50% MTF LANL definition) as < 1.7 mm (Axis I) and 1.9-2.8 mm (Axis II), with less than 1.5 mm beam motion between Axis II pulses. The Bucky Grid camera system was used for Axis I, while Axis II had a unique four-frame camera developed jointly by MIT Lincoln Laboratory. Imaging the initial shock wave traveling through the flyer plate, DARHT Axis II captured the range of motion from the shock front emergence in the flyer to breakout at the free surface; the Axis I pulse provided a perpendicular perspective of the shot at a time coinciding with the third pulse of Axis II. Shock speed in the material and other time-dependent properties such as material damage progression are measured using the time-evolved data from Axis II, while density reconstructions are made from the views of Axes I and II. The radiographs from Axis I and Axis II pulse 3 are compared in order to generate a three-dimensional image of the shocked material, enabling

  13. A comparison of on-axis and off-axis heliostat alignment strategies

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S.A.

    1996-03-01

    Heliostat installation and alignment costs will be an important element in future solar power tower projects. The predicted annual performances of on- and-off axis strategies are compared for 95 m{sup 2} flat-glass heliostats and an external, molten-salt receiver. Actual approaches to heliostat alignment that have been used in the past are briefly discussed, and relative strengths and limitations are noted. The optimal approach can vary with the application.

  14. Energy Efficient Hybrid Dual Axis Solar Tracking System

    OpenAIRE

    Rashid Ahammed Ferdaus; Mahir Asif Mohammed; Sanzidur Rahman; Sayedus Salehin; Mohammad Abdul Mannan

    2014-01-01

    This paper describes the design and implementation of an energy efficient solar tracking system from a normal mechanical single axis to a hybrid dual axis. For optimizing the solar tracking mechanism electromechanical systems were evolved through implementation of different evolutional algorithms and methodologies. To present the tracker, a hybrid dual-axis solar tracking system is designed, built, and tested based on both the solar map and light sensor based continuous tracking mechanism. Th...

  15. Analysis and design of a vertical axis wind turbine

    OpenAIRE

    Goyena Iriso, Joseba

    2011-01-01

    The main objective of this project is to design a new vertical axis wind turbine, specifically one Giromill wind turbine. The project development requires performing a previous study of the vertical axis wind turbines currently development. This study has to be performed before starting to design the wind turbine. Other very important aim is the development of a new vertical axis wind turbine. The after analyses that will result in the final design of the wind turbine will b...

  16. Growth Hormone-Insulin-Like Growth Factor Axis, Thyroid Axis, Prolactin, and Exercise.

    Science.gov (United States)

    Hackney, Anthony C; Davis, Hope C; Lane, Amy R

    2016-01-01

    This chapter addresses what is known about the endocrine system components growth hormone (GH)-insulin-like growth factor (IGF) axis, thyroid axis, and prolactin relative to exercise and exercise training. Each one of these hormone axes contributes to the maintenance of homeostasis in the body through impact on a multitude of physiological systems. The homeostatic disruption of exercise causes differing responses in each hormone axis. GH levels increase with sufficient stimulation, and IGFs are released in response to GH from the anterior pituitary providing multiple roles including anabolic properties. Changes in the thyroid hormones T3 and T4 vary greatly with exercise, from increases/decreases to no change in levels across different exercise types, intensities and durations. These ambiguous findings could be due to numerous confounding factors (e.g. nutrition status) within the research. Prolactin increases proportionally to the intensity of the exercise. The magnitude may be augmented with extended durations; conflicting findings have been reported with resistance training. While the responses to exercise vary, it appears there may be overall adaptive and regenerative impacts on the body into recovery by these hormones through immune and tissue inflammatory responses/mediations. Nonetheless, well-designed exercise research studies are still needed on each of these hormones, especially thyroid hormones and prolactin. PMID:27348437

  17. The multi-axis vibration environment and man.

    Science.gov (United States)

    Lovesey, E J

    1970-12-01

    Many investigations into the effects of vibration on man have been performed since Mallock's first study of London Underground vibrations in 1902. The vibration research has tended to be confined to the vertical (heave) axis, yet recent experiments have indicated that low frequency vibration along the lateral (sway) axis has a greater adverse effect upon comfort and performance. Measurements of the vibration environments in current forms of transport including motor vehicles, hovercraft and aircraft etc have shown that appreciable quantities of vibration along all three axes exist. Further vibration research should consider the effects of multi-axis vibrations upon man rather than limit tests to single axis vibration. PMID:15676336

  18. Comparison of long-axis and short-axis PROPELLER-EPI for diffusion-weighted magnetic resonance imaging; Vergleich von Long-Axis- und Short-Axis-PROPELLER-EPI fuer die diffusionsgewichtete Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Rossbach, Matthias; Jochimsen, Thies H.; Herrmann, Karl-Heinz; Ros, Christian; Guellmar, Daniel; Reichenbach, Juergen R. [Jena Univ. Hospital (Germany). Medical Physics Group

    2011-07-01

    Echo planar imaging (EPI) in combination with PROPELLER allows high-resolution diffusion-weighted imaging. In this study, the image quality of short-axis and long-axis PROPELLER was compared and optimized using phantom and in vivo data. Furthermore, diffusion-weighted measurements using both sequences were compared with those of a reference sequence. It was found that the long-axis sequence provided better image quality, whereas the results of the diffusion weighted measurements were more accurate with the short-axis variant, and that the results of the diffusion weighted measurements of both sequences agreed well with those of the reference sequence. (orig.)

  19. Microbiota and the gut-brain axis.

    Science.gov (United States)

    Bienenstock, John; Kunze, Wolfgang; Forsythe, Paul

    2015-08-01

    Changes in gut microbiota can modulate the peripheral and central nervous systems, resulting in altered brain functioning, and suggesting the existence of a microbiota gut-brain axis. Diet can also change the profile of gut microbiota and, thereby, behavior. Effects of bacteria on the nervous system cannot be disassociated from effects on the immune system since the two are in constant bidirectional communication. While the composition of the gut microbiota varies greatly among individuals, alterations to the balance and content of common gut microbes may affect the production of molecules such as neurotransmitters, e.g., gamma amino butyric acid, and the products of fermentation, e.g., the short chain fatty acids butyrate, propionate, and acetate. Short chain fatty acids, which are pleomorphic, especially butyrate, positively influence host metabolism by promoting glucose and energy homeostasis, regulating immune responses and epithelial cell growth, and promoting the functioning of the central and peripheral nervous systems. In the future, the composition, diversity, and function of specific probiotics, coupled with similar, more detailed knowledge about gut microbiota, will potentially help in developing more effective diet- and drug-based therapies. PMID:26175487

  20. Yaw dynamics of horizontal axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))

    1992-05-01

    Designers of a horizontal axis wind turbine yaw mechanism are faced with a difficult decision. They know that if they elect to use a yaw- controlled rotor then the system will suffer increased initial cost and increased inherent maintenance and reliability problems. On the other hand, if they elect to allow the rotor to freely yaw they known they will have to account for unknown and random, though bounded, yaw rates. They will have a higher-risk design to trade-off against the potential for cost savings and reliability improvement. The risk of a yaw-free system could be minimized if methods were available for analyzing and understanding yaw behavior. The complexity of yaw behavior has, until recently, discouraged engineers from developing a complete yaw analysis method. The objectives of this work are to (1) provide a fundamental understanding of free-yaw mechanics and the design concepts most effective at eliminating yaw problems, and (2) provide tested design tools and guidelines for use by free-yaw wind systems manufacturers. The emphasis is on developing practical and sufficiently accurate design methods.

  1. Six axis force feedback input device

    Science.gov (United States)

    Ohm, Timothy (Inventor)

    1998-01-01

    The present invention is a low friction, low inertia, six-axis force feedback input device comprising an arm with double-jointed, tendon-driven revolute joints, a decoupled tendon-driven wrist, and a base with encoders and motors. The input device functions as a master robot manipulator of a microsurgical teleoperated robot system including a slave robot manipulator coupled to an amplifier chassis, which is coupled to a control chassis, which is coupled to a workstation with a graphical user interface. The amplifier chassis is coupled to the motors of the master robot manipulator and the control chassis is coupled to the encoders of the master robot manipulator. A force feedback can be applied to the input device and can be generated from the slave robot to enable a user to operate the slave robot via the input device without physically viewing the slave robot. Also, the force feedback can be generated from the workstation to represent fictitious forces to constrain the input device's control of the slave robot to be within imaginary predetermined boundaries.

  2. Gut-liver axis and sensing microbes.

    Science.gov (United States)

    Szabo, Gyongyi; Bala, Shashi; Petrasek, Jan; Gattu, Arijeet

    2010-01-01

    'Detoxification' of gut-derived toxins and microbial products from gut-derived microbes is a major role of the liver. While the full repertoire of gut-derived microbial products that reach the liver in health and disease is yet to be explored, the levels of bacterial lipopolysaccharide (LPS), a component of Gram-negative bacteria, is increased in the portal and/or systemic circulation in several types of chronic liver diseases. Increased gut permeability and LPS play a role in alcoholic liver disease where alcohol impairs the gut epithelial integrity through alterations in tight junction proteins. In addition, non-alcoholic fatty liver disease is also associated with increased serum LPS levels and activation of the pro-inflammatory cascade plays a central role in disease progression. Microbial danger signals are recognized by pattern recognition receptors such as the Toll-like receptor 4 (TLR4). Increasing evidence suggests that TLR4-mediated signaling via the MyD88-dependent or MyD88-independent pathways may play different roles in liver diseases associated with increased LPS exposure of the liver as a result of gut permeability. For example, we showed that in alcoholic liver disease, the MyD88-independent, IRF3-dependent TLR4 cascade plays a role in steatosis and inflammation. Our recent data demonstrate that chronic alcohol exposure in the liver leads to sensitization of Kupffer cells to LPS via a mechanism involving upregulation of microRNA-155 in Kupffer cells. Thus, understanding the cell-specific recognition and intracellular signaling events in sensing gut-derived microbes will help to achieve an optimal balance in the gut-liver axis and ameliorate liver diseases. PMID:21525758

  3. Turbulence in vertical axis wind turbine canopies

    Science.gov (United States)

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-11-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the importance of vertical transport for large array configurations. Quadrant-hole analysis is employed to gain a better understanding of the vertical energy transport at the top of the VAWT arrays. The results show a striking similarity between the flows in the VAWT arrays and the adjustment region of canopies. Namely, an increase in ejections and sweeps and decrease in inward and outward interactions occur inside the turbine array. Ejections are the strongest contributor, which is in agreement with the literature on evolving and sparse canopy flows. The influence of the turbine array size on the power output of the downstream turbines is examined by comparing a streamwise row of four single turbines with square arrays of nine turbine pairs. The results suggest that a new boundary layer forms on top of the larger turbine arrays as the flow adjusts to the new roughness length. This increases the turbulent energy transport over the whole planform area of the turbine array. By contrast, for the four single turbines, the vertical energy transport due to turbulent fluctuations is only increased in the near wake of the turbines. These findings add to the knowledge of energy transport in turbine arrays and therefore the optimization of the turbine spacing in wind farms.

  4. Distortion definition and correction in off-axis systems

    Science.gov (United States)

    Da Deppo, Vania; Simioni, Emanuele; Naletto, Giampiero; Cremonese, Gabriele

    2015-09-01

    Off-axis optical configurations are becoming more and more used in a variety of applications, in particular they are the most preferred solution for cameras devoted to Solar System planets and small bodies (i.e. asteroids and comets) study. Off-axis designs, being devoid of central obstruction, are able to guarantee better PSF and MTF performance, and thus higher contrast imaging capabilities with respect to classical on-axis designs. In particular they are suitable for observing extended targets with intrinsic low contrast features, or scenes where a high dynamical signal range is present. Classical distortion theory is able to well describe the performance of the on-axis systems, but it has to be adapted for the off-axis case. A proper way to deal with off-axis distortion definition is thus needed together with dedicated techniques to accurately measure and hence remove the distortion effects present in the acquired images. In this paper, a review of the distortion definition for off-axis systems will be given. In particular the method adopted by the authors to deal with the distortion related issues (definition, measure, removal) in some off-axis instruments will be described in detail.

  5. Spin-stabilized magnetic levitation without vertical axis of rotation

    Science.gov (United States)

    Romero, Louis; Christenson, Todd; Aaronson, Gene

    2009-06-09

    The symmetry properties of a magnetic levitation arrangement are exploited to produce spin-stabilized magnetic levitation without aligning the rotational axis of the rotor with the direction of the force of gravity. The rotation of the rotor stabilizes perturbations directed parallel to the rotational axis.

  6. Angular momentum projection of tilted axis rotating states

    Energy Technology Data Exchange (ETDEWEB)

    Oi, M.; Onishi, N.; Tajima, N. [Tokyo Univ. (Japan); Horibata, T.

    1998-03-01

    We applied an exact angular momentum projection to three dimensional cranked HFB (3d-CHFB) states. Tilted axis rotating states (TAR) and principal axis rotating states (PAR) are compared. It is shown that TAR is more adequate than PAR for description of the back bending phenomena driven by tilted rotation or wobbling motion. (author)

  7. Exercise and the Hypothalamo-Pituitary-Adrenal Axis.

    Science.gov (United States)

    Duclos, Martine; Tabarin, Antoine

    2016-01-01

    Exercise represents a potent physiological stimulus upon the hypothalamo-pituitary adrenal (HPA) axis. Two major factors modulate the HPA axis response to exercise: intensity and duration. Endurance training per se does not induce permanent hypercortisolism as endurance-trained subjects have similar biological markers of HPA axis activity in resting condition as healthy untrained men. However, during a challenge of the HPA axis, endurance-trained subjects demonstrate an adaptation of the HPA axis activity to repeated exercise resulting from decreased tissular sensitivity to glucocorticoids. A great diversity of other mechanisms is involved in this adaptation, acting potentially at all levels in the cascade and leading to the biological effects of cortisol. PMID:27348531

  8. ACCURATE MEASUREMENT OF ROTA-RY MACHINE AXIS CENTER TRACE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Four methods aiming at measuring rotary machine axis center trace are discussed in detail.The comparative analysis is made on some aspects such as measurement accuracy, on-machine characteristics, feasibility, practical operation convenience and the integrity of measurement information.In order to simplify measurement, the axis profile error is ignored in traditional condition, while the measurement accuracy will be reduced.The 3-point method that the axis profile error is firstly separated has better real time character, at the same time, not only the axis motion error but also the axis profile error can be measured.All of those information can be used to diagnose the fault origin.The analysis result is proved to be correct by the experiment.

  9. Notes on Mugger Crocodile Crocodylus palustris (Lesson, 1831) hunting on Axis axis in Bardia National Park, Nepal

    OpenAIRE

    Bhattarai, Santosh

    2016-01-01

    Mugger Crocodile Crocodylus palustris is a specialized voracious predator. Hunting strategy of the Mugger on the Axis axis deer and food storing for later use behavior of Crocodylus palustris is documented in Bardia National Park, Nepal. Understanding the diet of the Mugger is of great significance in Bardia National Park for its conservation and management.

  10. Computational studies of horizontal axis wind turbines

    Science.gov (United States)

    Xu, Guanpeng

    A numerical technique has been developed for efficiently simulating fully three-dimensional viscous fluid flow around horizontal axis wind turbines (HAWT) using a zonal approach. The flow field is viewed as a combination of viscous regions, inviscid regions and vortices. The method solves the costly unsteady Reynolds averaged Navier-Stokes (RANS) equations only in the viscous region around the turbine blades. It solves the full potential equation in the inviscid region where flow is irrotational and isentropic. The tip vortices are simulated using a Lagrangean approach, thus removing the need to accurately resolve them on a fine grid. The hybrid method is shown to provide good results with modest CPU resources. A full Navier-Stokes based methodology has also been developed for modeling wind turbines at high wind conditions where extensive stall may occur. An overset grid based version that can model rotor-tower interactions has been developed. Finally, a blade element theory based methodology has been developed for the purpose of developing improved tip loss models and stall delay models. The effects of turbulence are simulated using a zero equation eddy viscosity model, or a one equation Spalart-Allmaras model. Two transition models, one based on the Eppler's criterion, and the other based on Michel's criterion, have been developed and tested. The hybrid method has been extensively validated for axial wind conditions for three rotors---NREL Phase II, Phase III, and Phase VI configurations. A limited set of calculations has been done for rotors operating under yaw conditions. Preliminary simulations have also been carried out to assess the effects of the tower wake on the rotor. In most of these cases, satisfactory agreement has been obtained with measurements. Using the numerical results from present methodologies as a guide, Prandtl's tip loss model and Corrigan's stall delay model were correlated with present calculations. An improved tip loss model has been

  11. Off-axis illumination direct-to-digital holography

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Clarence E.; Price, Jeffery R.; Voelkl, Edgar; Hanson, Gregory R.

    2004-06-08

    Systems and methods are described for off-axis illumination direct-to-digital holography. A method of recording an off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis, includes: reflecting a reference beam from a reference mirror at a non-normal angle; reflecting an object beam from an object at an angle with respect to an optical axis defined by a focusing lens; focusing the reference beam and the object beam at a focal plane of a digital recorder to form the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; digitally recording the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; Fourier analyzing the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes by transforming axes of the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes in Fourier space to sit on top of a heterodyne carrier frequency defined as an angle between the reference beam and the object beam; applying a digital filter to cut off signals around an original origin; and then performing an inverse Fourier transform.

  12. Kinematic and Dynamic Analyses of the Orthoglide 5-axis

    CERN Document Server

    Ur-Rehman, Raza; Chablat, Damien; Wenger, Philippe

    2008-01-01

    This paper deals with the kinematic and dynamic analyses of the Orthoglide 5-axis, a five-degree-of-freedom manipulator. It is derived from two manipulators: i) the Orthoglide 3-axis; a three dof translational manipulator and ii) the Agile eye; a parallel spherical wrist. First, the kinematic and dynamic models of the Orthoglide 5-axis are developed. The geometric and inertial parameters of the manipulator are determined by means of a CAD software. Then, the required motors performances are evaluated for some test trajectories. Finally, the motors are selected in the catalogue from the previous results.

  13. The Post Processing Developing of Five-axis CNC Machine

    Directory of Open Access Journals (Sweden)

    Anjiang Cai

    2012-07-01

    Full Text Available In this study, we have a research of the methods of the special post processing program developing of Five-axis CNC machine DMC 70ev. On the basis of analysis about the characteristics of MILLPLUS IT V530 CNumerical control system, special post processor applied to five-axis CNC machining mode based on IMSPost was developed. Special post processing program developed was proved its accuracy and reliability by put it into practice. The research results has important significance for post processing developing of other types of five-axis CNC machines and provides a guideline for the post processing program of other CAD/CAM software.

  14. Design characteristics to reduce inadvertent cross-axis coupling during side stick handling of aircraft pitch and roll axis control

    Science.gov (United States)

    Cote, Marie-Eve

    Integrating a manual flight control inceptor with coupled axes such as the side stick within a flight deck creates challenges for the pilot to input a one-axis command without inadvertently inducing inputs in the opposite axis. The present paper studies three design features of the side stick and armrest setup believed to help reduce inadvertent cross-axis coupling occurrences. Design features address the aimed pilot population anthropometry (1.57m woman to 1.9m male) and their variability in upper segment measurements. Seven pilots of varying anthropometric sizes were asked to perform one-axis manoeuvres in pitch and roll for each setup configuration. To compare the setups both the duration and the definite integral of the unintended cross-axis input were processed and analyzed for each manoeuvre. Findings show that a short armrest reduces the occurrences of cross-axis input for the roll manoeuvre, whereas the side stick skew reduces inadvertent cross-axis coupling for the pitch manoeuvres.

  15. REGULATION OF THE THYROID AXIS IN DEVELOPING XENOPUS LAEVIS

    Science.gov (United States)

    The focus of the research presented here is the development of an in vitro pituitary gland culture system to test the effect of chemicals directly on the gland without influence of other parts of the HPT axis.

  16. Space/Flight Operable Miniature Six Axis Transducer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FUTEK will fully design and manufacture a sensor capable of measuring forces in and about each axis. The unit will measure forces up to 300 Newton's in the...

  17. The effects of lateral head tilt on ocular astigmatic axis

    Directory of Open Access Journals (Sweden)

    Hamid Fesharaki

    2014-01-01

    Conclusion: Any minimal angle of head tilt may cause erroneous measurement of astigmatic axis and should be avoided during refraction. One cannot rely on the compensatory function of ocular counter-torsion during the refraction.

  18. Gonadal steroid hormones and the hypothalamo-pituitary-adrenal axis.

    Science.gov (United States)

    Handa, Robert J; Weiser, Michael J

    2014-04-01

    The hypothalamo-pituitary-adrenal (HPA) axis represents a complex neuroendocrine feedback loop controlling the secretion of adrenal glucocorticoid hormones. Central to its function is the paraventricular nucleus of the hypothalamus (PVN) where neurons expressing corticotropin releasing factor reside. These HPA motor neurons are a primary site of integration leading to graded endocrine responses to physical and psychological stressors. An important regulatory factor that must be considered, prior to generating an appropriate response is the animal's reproductive status. Thus, PVN neurons express androgen and estrogen receptors and receive input from sites that also express these receptors. Consequently, changes in reproduction and gonadal steroid levels modulate the stress response and this underlies sex differences in HPA axis function. This review examines the make up of the HPA axis and hypothalamo-pituitary-gonadal (HPG) axis and the interactions between the two that should be considered when exploring normal and pathological responses to environmental stressors. PMID:24246855

  19. Determination of Elastic Twist in Horizontal Axis Wind Turbines (HAWTs)

    Energy Technology Data Exchange (ETDEWEB)

    Stoddard, F.; Nelson, V.; Starcher, K.; Andrews, B.

    2006-06-01

    This report presents the results of a project at the Alternative Energy Institute (AEI) which measured and calculated the elastic twist of three representative composite horizontal-axis blades: Carter 300, Gougeon ESI 54, and UTRC 8 kW.

  20. A Method for Modeling of Floating Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Wang, Kai; Hansen, Martin Otto Laver; Moan, Torgeir

    2013-01-01

    It is of interest to investigate the potential advantages of floating vertical axis wind turbine (FVAWT) due to its economical installation and maintenance. A novel 5MW vertical axis wind turbine concept with a Darrieus rotor mounted on a semi-submersible support structure is proposed in this paper....... In order to assess the technical and economic feasibility of this novel concept, a comprehensive simulation tool for modeling of the floating vertical axis wind turbine is needed. This work presents the development of a coupled method for modeling of the dynamics of a floating vertical axis wind turbine....... This integrated dynamic model takes into account the wind inflow, aerodynamics, hydrodynamics, structural dynamics (wind turbine, floating platform and the mooring lines) and a generator control. This approach calculates dynamic equilibrium at each time step and takes account of the interaction between the rotor...

  1. The Minimal Model of the Hypothalamic-Pituitary-Adrenal Axis

    DEFF Research Database (Denmark)

    Vinther, Frank; Andersen, Morten; Ottesen, Johnny T.

    2011-01-01

    This paper concerns ODE modeling of the hypothalamic-pituitary-adrenalaxis (HPA axis) using an analytical and numerical approach, combined with biological knowledge regarding physiological mechanisms and parameters. The three hormones, CRH, ACTH, and cortisol, which interact in the HPA axis...... from an unstable fixed point with complex eigenvalues with a positive real parts and a non-zero imaginary parts. The first part of the paper describes the general considerations to be obeyed for a mathematical model of the HPA axis. In this paper we only include the most widely accepted mechanisms...... that influence the dynamics of the HPA axis, i.e. a negative feedback from cortisol on CRH and ACTH. Therefore we term our model the minimal model. The minimal model, encompasses a wide class of different realizations, obeying only a few physiologically reasonable demands. The results include the existence...

  2. Circular Interpolation Algorithms of 5-Axis Simultaneous CNC System

    Institute of Scientific and Technical Information of China (English)

    ZHENG Kuijing; SHANG Bo

    2006-01-01

    Spatial circular arc can be machined conveniently by a 5-axis NC machine tool. Based on the data sampling method, circular interpolation in two-dimensional plane is discussed briefly. The key is to solve the problem of circular center expressed in the workpiece coordinate system by means of the transformation matrix. Circular interpolation in three-dimensional space is analyzed in detail. The method of undetermined coefficient is used to solve the center of the spatial circle and the method of coordinate transformation is used to transform the spatial circle into the XY_plane. Circular arc in three-dimensional space can be machined by the positional 5-axis machining and the conical surface can be machined by the continuous 5-axis machining. The velocity control is presented to avoid the feedrate fluctuation. The interpolation algorithms are tested by a simulation example and the interpolation algorithms are proved feasible. The algorithms are applied to the 5-axis CNC system software.

  3. Application of circulation controlled blades for vertical axis wind turbines

    OpenAIRE

    Velissarios Kourkoulis; Andrew Shires

    2013-01-01

    The blades of a vertical axis wind turbine (VAWT) rotor see an inconsistent angle of attack through its rotation. Consequently, VAWT blades generally use symmetrical aerofoils with a lower lift-to-drag ratio than cambered aerofoils tailored to maximise horizontal axis wind turbine rotor performance. This paper considers the feasibility of circulation controlled (CC) VAWT blades, using a tangential air jet to provide lift and therefore power augmentation. However CC blade sections require a hi...

  4. Dynamic Compensation for Two-Axis Robot Wrist Force Sensors

    OpenAIRE

    Junqing Ma; Aiguo Song; Dongcheng Pan

    2013-01-01

    To improve the dynamic characteristic of two-axis force sensors, a dynamic compensation method is proposed. The two-axis force sensor system is assumed to be a first-order system. The operation frequency of the system is expanded by a digital filter with backward difference network. To filter high-frequency noises, a low-pass filter is added after the dynamic compensation network. To avoid overcompensation, parameters of the proposed dynamic compensation method are defined by trial and error....

  5. Rotation axis demultiplexer enabling simultaneous computed tomography of multiple samples

    OpenAIRE

    Trtik, Pavel; Geiger, Fabian; Hovind, Jan; Lang, Udo; Lehmann, Eberhard; Vontobel, Peter; Peetermans, Steven

    2016-01-01

    This paper describes a device that allows for simultaneous tomographic imaging of samples on three independent rotational axes. This rotation axis demultiplexer (POLYTOM) is equipped with anti-backlash gears and placed on a standard sample rotation stage thus allowing for the transformation of the input rotation axis onto two additional parallel vertical axes. Consequently, three times the number of samples can be investigated within a given time period, thereby reducing the acquisition time ...

  6. MAP: Medial axis based geometric routing in sensor networks

    OpenAIRE

    Bruck, Jehoshua; Gao, Jie; Jiang, Anxiao

    2007-01-01

    One of the challenging tasks in the deployment of dense wireless networks (like sensor networks) is in devising a routing scheme for node to node communication. Important consideration includes scalability, routing complexity, quality of communication paths and the load sharing of the routes. In this paper, we show that a compact and expressive abstraction of network connectivity by the medial axis enables efficient and localized routing. We propose MAP, a Medial Axis based naming and routing...

  7. The reno-pineal axis: A novel role for melatonin

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2012-01-01

    Full Text Available The pineal gland is a tiny endocrine gland whose physiologic role has been the focus of much research and much more speculation over the past century. This mini-review discusses recent findings which correlate melatonin and renal physiology, and postulates the presence of a "reno-pineal axis." Drawing lessons from comparative endocrinology, while quoting human data, it advocates the need to study the "reno-pineal axis" in greater detail.

  8. Experimental study of the subtalar joint axis: preliminary investigation.

    Science.gov (United States)

    Zographos, S; Chaminade, B; Hobatho, M C; Utheza, G

    2000-01-01

    An experimental study of the subtalar joint has been conducted with the aim of establishing its axis of movement as well as analysing the associated movement. For description of the axis, CT data for five positions of a single foot were reconstructed using a 3D programme, the 3D data was processed by Patran software. Measures of angular displacements were made from three amputated feet placed in a specially constructed foot frame. Four instantaneous axes of movement could be defined. Calculation of displacements showed an important rolling of the calcaneus (45 degrees). Tacking was evident in inversion, with an opposite displacement between the front and rear part of the calcaneus, whereas during eversion tacking affected only the rear part of the bone: these results were confirmed by 3D reconstructions. Henke's axis was described as that for the talonavicular joint, but acceptable for the subtalar joint. Several authors investigating the coordinates of this axis have reported large differences and described screw-like movements, the latter being incompatible with a fixed axis: instantaneous axes, however are compatible with a screw-like movement. The subtalar joint appears to work as a pivot joint during inversion and as a plane joint during eversion. Although Henke's axis has pedagogical value the subtalar joint has a series of instantaneous axes. PMID:11236321

  9. Off-Axis Aspheric Surfacing Using Sub-Aperture Tools

    Science.gov (United States)

    Feng, Yunpeng; Qiao, Xiaoyan; Cheng, Haobo; Tam, Hon-Yuen

    2013-10-01

    The off-axis aspheric surface used in modern optical systems widely can obtain nearly perfect quality, realize both small packet-size and low-mass, and avoid the central obscuration. But it is difficult to fabricate because of asymmetry. There are some key technologies during the testing and fabrication of off-axis asphere. In this article, we proposed a method of the best fit sphere based on non-negative minimized removal criterion. And a measured data fitting algorithm was presented to estimate the geometry parameters of off-axis aspheric surface. Then an off-axis mirror was fabricated, and the interferometrically measured data was corrected to eliminate the distortion introduced by null compensator in every run. Finally, the surface error of off-axis mirror reduced to pv = 0.372λ, rms = 0.046λ, the surface roughness reached 0.72 nm. These methods mentioned in the article are suitable for off-axis aspheric optics.

  10. Major and minor axis kinematics of 22 ellipticals

    Science.gov (United States)

    Franx, Marijn; Illingworth, Garth; Heckman, Timothy

    1989-09-01

    Rotation curves and velocity dispersion profiles have been determined for the major and the minor axes of 22 elliptical galaxies. Rotation was detected in all but one galaxy, even though the sample was biased toward round ellipticals. Minor axis rotation larger than major axis rotation was measured in two galaxies, NGC 4406 and NGC 7507. Roughly 10 percent of ellipticals may show large minor axis velocities relative to those on the major axis. A simple model is used to derive a rotational axis from the observed minor and major axis velocities to a typical accuracy of 6 deg. The rotational and photometric minor axes aligned to better than 10 deg for 60 percent of the sample, implying that the direction of the angular momentum is related to the orientation of the figure of the galaxy. IC 1459 has a kinematically distinct core with its angular momentum opposite to the angular momentum of the outer parts, and NGC 4406 has a core with its angular momentum perpendicular to that of the outer parts.

  11. Optic axis-driven new horizons for hyperbolic metamaterials

    Directory of Open Access Journals (Sweden)

    Boardman Allan D.

    2015-01-01

    Full Text Available The broad assertion here is that the current hyperbolic metamaterial world is only partially served by investigations that incorporate only some limited version of anisotropy. Even modest deviations of the optic axis from the main propagation axis lead to new phase shifts, which not only compete with those created by absorption but end up dominating them. Some progress has been attempted in the literature by introducing the terms “asymmetric hyperbolic media”, but it appears that this kind of asymmetry only involves an optic axis at an angle to the interface of a uniaxial crystal. From a device point of view, many new prospects should appear and the outcomes of the investigations presented here yield a new general theory. It is emphasised that the orientation of the optic axis is a significant determinant in the resulting optical properties. Whereas for conventional anisotropic waveguides homogeneous propagating waves occur over a limited range of angular dispositions of the optic axis it is shown that for a hyperbolic guide a critical angular setting exists, above which the guided waves are always homogeneous. This has significant implications for metawaveguide designs. The resulting structures are more tolerant to optic axis misalignment.

  12. 艾灸对血管性痴呆大鼠海马内VEGF、flt-1、bFGF及bFGF-r表达的影响%Effects of Moxibustion on the Expressions of Hlppocampal VEGF, fit-1, bFGF, and bFGF-r in Vascular

    Institute of Scientific and Technical Information of China (English)

    王频; 汤敬一; 杨骏; 张庆萍

    2012-01-01

    Objective To observe the expression levels of hippocampal vascular endothelial growth factor (VEGF), fms-like tyrosine kinase-1 (flt-1), basic fibroblast growth factor (bFGF), and basic fibroblast growth factor receptor (bFGF-r) in vascular dementia (VD) rats, thus studying the angiogenesis mechanism of moxi-bustion in VD. Methods Sixty male elderly Wistar rats were selected. The VD rat model was prepared by bilateral carotid artery occlusion and reperfusion of sodium nitroprusside injection. The model rats were divided into 3 groups by the random digit table, I. E., the moxibustion group, the Western medicine group, and the model group. A sham-operation control group was also set up. In the moxibustion group rats was acupunctured at Baihui (GV20), Shenting (GV14), and Dazhui (GV24). Aniracetam was given to rats in the Western medicine group by gastrogavage for 2 therapeutic courses, 15 days as one course. The learning and memory results were observed by the neuroethological score in combination of step-down avoidance test before treatment and by the end of the 2nd course respectively. The expression levels of hippocampal VEGF, flt-1, bFGF, and bFGF-r of allrats were detected using immunohistochemical assay. Results After 2 courses of treatment, statistical difference existed in the latent period, the error times, and the neuroethological score in the moxibustion group and the Western medicine group when compared with the model group (P<0.01, P<0. 05). Statistical difference existed in the latent period and the neuroethological score between the moxibustion group and the Western medicine group (P<0. 05), which indicated that moxibustion and Western medicine showed significant effects in improving the latent period, decreasing the error times and the neuroethological score. Better results were obtained in the moxibustion group than in the Western medicine group (P<0. 01, P<0. 05). Statistical difference of the average grey level (AGL) of hippocampal VEGF, flt-1, and

  13. Mifepristone Accelerates HPA Axis Recovery in Secondary Adrenal Insufficiency

    Science.gov (United States)

    2016-01-01

    Context. Transient secondary adrenal insufficiency (SAI) is an expected complication following successful adenomectomy of ACTH-secreting pituitary adenomas or unilateral adrenalectomy for cortisol-secreting adrenal adenomas. To date, no pharmacological therapy has been shown to hasten recovery of the hypothalamic-pituitary-adrenal (HPA) axis in this clinical scenario. Case Description. A 33-year-old woman underwent uncomplicated unilateral adrenalectomy for a 3.7 cm cortisol-secreting adrenal adenoma. Postoperatively, she developed SAI and was placed on hydrocortisone 15 mg/day, given in divided doses. In the ensuing six years, the patient's HPA axis failed to recover and she remained corticosteroid-dependent. Quarterly biochemical testing (after withholding hydrocortisone for 18 hours) consistently yielded undetectable serum cortisol and subnormal plasma ACTH levels. While she was on hydrocortisone 15 mg/day, mifepristone was initiated and gradually titrated to a maintenance dose of 600 mg/day after 5 months. Rapid recovery of the HPA axis was subsequently noted with ACTH rising into the supranormal range at 4 months followed by a subsequent rise in cortisol levels into the normal range. After 6 months, the dose of hydrocortisone and mifepristone was lowered and both were ultimately stopped after 8 months. The HPA axis remains normal after an additional 16 months of follow-up. Conclusion. Mifepristone successfully restored the HPA axis in a woman with prolonged secondary adrenal insufficiency (SAI) after adrenalectomy for Cushing's syndrome (CS). PMID:27516913

  14. Off-axis angular spectrum method with variable sampling interval

    Science.gov (United States)

    Kim, Yong-Hae; Byun, Chun-Won; Oh, Himchan; Pi, Jae-Eun; Choi, Ji-Hun; Kim, Gi Heon; Lee, Myung-Lae; Ryu, Hojun; Hwang, Chi-Sun

    2015-08-01

    We proposed a novel off-axis angular spectrum method (ASM) for simulating free space wave propagation with a large shifted destination plane. The off-axis numerical simulation took wave propagation between a parallel source and a destination plane, but a destination plane was shifted from a source plane. The shifted angular spectrum method was proposed for diffraction simulation with a shifted destination plane and satisfied the Nyquist condition for sampling by limiting a bandwidth of a propagation field to avoid an aliasing error due to under sampling. However, the effective sampling number of the shifted ASM decreased when the shifted distance of the destination plane was large which caused a numerical error in the diffraction simulation. To compensate for the decrease of an effective sampling number for the large shifted destination plane, we used a variable sampling interval in a Fourier space to maintain the same effective sampling number independent of the shifted distance of the destination plane. As a result, our proposed off-axis ASM with a variable sampling interval can produce simulation results with high accuracy for nearly every shifted distance of a destination plane when an off-axis angle is less than 75°. We compared the performances of the off-axis ASM using the Chirp Z transform and non-uniform FFT for implementing a variable spatial frequency in a Fourier space.

  15. Measurement Axis Searching Model for Terrestrial Laser Scans Registration

    Directory of Open Access Journals (Sweden)

    Shaoxing Hu

    2016-01-01

    Full Text Available Nowadays, terrestrial Lidar scans can cover rather a large area; the point densities are strongly varied because of the line-of-sight measurement principle in potential overlaps with scans taken from different viewpoints. Most of the traditional methods focus on registration algorithm and ignore searching model. Sometimes the traditional methods are directly used to align two point clouds; a large critically unsolved problem of the large biases will be created in areas distant from the overlaps while the local overlaps are often aligned well. So a novel measurement axis searching model (MASM has been proposed in this paper. The method includes four steps: (1 the principal axis fitting, (2 the measurement axis generation, (3 low-high-precision search, and (4 result generation. The principal axis gives an orientation to the point cloud; the search scope is limited by the measurement axis. The point cloud orientation can be adjusted gradually until the achievement of the global optimum using low- and high-precision search. We perform some experiments with simulated point clouds and real terrestrial laser scans. The results of simulated point clouds have shown the processing steps of our method, and the results of real terrestrial laser scans have shown the sensitivity of the approach with respect to the indoor and outdoor scenes.

  16. Magnetic axis alignment and the Poisson alignment reference system

    Science.gov (United States)

    Griffith, Lee V.; Schenz, Richard F.; Sommargren, Gary E.

    1989-01-01

    Three distinct metrological operations are necessary to align a free-electron laser (FEL): the magnetic axis must be located, a straight line reference (SLR) must be generated, and the magnetic axis must be related to the SLR. This paper begins with a review of the motivation for developing an alignment system that will assure better than 100 micrometer accuracy in the alignment of the magnetic axis throughout an FEL. The paper describes techniques for identifying the magnetic axis of solenoids, quadrupoles, and wiggler poles. Propagation of a laser beam is described to the extent of revealing sources of nonlinearity in the beam. Development and use of the Poisson line, a diffraction effect, is described in detail. Spheres in a large-diameter laser beam create Poisson lines and thus provide a necessary mechanism for gauging between the magnetic axis and the SLR. Procedures for installing FEL components and calibrating alignment fiducials to the magnetic axes of the components are also described. An error budget shows that the Poisson alignment reference system will make it possible to meet the alignment tolerances for an FEL.

  17. Mifepristone Accelerates HPA Axis Recovery in Secondary Adrenal Insufficiency.

    Science.gov (United States)

    Cohan, Pejman

    2016-01-01

    Context. Transient secondary adrenal insufficiency (SAI) is an expected complication following successful adenomectomy of ACTH-secreting pituitary adenomas or unilateral adrenalectomy for cortisol-secreting adrenal adenomas. To date, no pharmacological therapy has been shown to hasten recovery of the hypothalamic-pituitary-adrenal (HPA) axis in this clinical scenario. Case Description. A 33-year-old woman underwent uncomplicated unilateral adrenalectomy for a 3.7 cm cortisol-secreting adrenal adenoma. Postoperatively, she developed SAI and was placed on hydrocortisone 15 mg/day, given in divided doses. In the ensuing six years, the patient's HPA axis failed to recover and she remained corticosteroid-dependent. Quarterly biochemical testing (after withholding hydrocortisone for 18 hours) consistently yielded undetectable serum cortisol and subnormal plasma ACTH levels. While she was on hydrocortisone 15 mg/day, mifepristone was initiated and gradually titrated to a maintenance dose of 600 mg/day after 5 months. Rapid recovery of the HPA axis was subsequently noted with ACTH rising into the supranormal range at 4 months followed by a subsequent rise in cortisol levels into the normal range. After 6 months, the dose of hydrocortisone and mifepristone was lowered and both were ultimately stopped after 8 months. The HPA axis remains normal after an additional 16 months of follow-up. Conclusion. Mifepristone successfully restored the HPA axis in a woman with prolonged secondary adrenal insufficiency (SAI) after adrenalectomy for Cushing's syndrome (CS). PMID:27516913

  18. Celiac axis stenosis and lethal liver ischemia after pancreaticoduodenectomy.

    Science.gov (United States)

    Lipska, Ludmila; Visokai, Vladimir; Levy, Miroslav; Koznar, Boris; Zaruba, Pavel

    2009-01-01

    Celiac axis stenosis can lead to a fatal hepatic ischemia after pancreaticoduodenectomy unless a simultaneous revascularisation of the celiac circulation is performed. In the present study are reported three cases of celiac axis stenosis, all of which had histologically confirmed periampullary cancer. Case 1: a 50-year-old male with a history of myocardial infarction and liver steatosis; visceral arteriography prior to the surgery demonstrated a celiac axis stenosis. Whipple operation was performed. After removing the specimen, no signs of liver ischemia were found (liver was cholestatic) and pulsation of the hepatic artery was strong. The patient died on the second postoperative day after an abrupt irreversible cardiac arrest. Autopsy proved acute severe hepatic ischemia. Case 2: a 64-year-old female. Preoperative visceral angiography showed significant celiac axis stenosis. As a first step of surgery the root of the celiac trunk was exposed, a fibrotic ring around it was divided. Standard D1 pylorus preserving pancreaticoduodenectomy was performed. Case 3: a 58-year-old female without preoperative angiography, indicated for surgery. After an occlusion test of the gastroduodenal artery the liver became ischemic. Division of the fibrotic ring around celiac axis was performed together with a standard D1 pylorus preserving pancreaticoduodenectomy. No postoperative complications were reported in both case 2 and 3. PMID:19760970

  19. Mifepristone Accelerates HPA Axis Recovery in Secondary Adrenal Insufficiency.

    Science.gov (United States)

    Cohan, Pejman

    2016-01-01

    Context. Transient secondary adrenal insufficiency (SAI) is an expected complication following successful adenomectomy of ACTH-secreting pituitary adenomas or unilateral adrenalectomy for cortisol-secreting adrenal adenomas. To date, no pharmacological therapy has been shown to hasten recovery of the hypothalamic-pituitary-adrenal (HPA) axis in this clinical scenario. Case Description. A 33-year-old woman underwent uncomplicated unilateral adrenalectomy for a 3.7 cm cortisol-secreting adrenal adenoma. Postoperatively, she developed SAI and was placed on hydrocortisone 15 mg/day, given in divided doses. In the ensuing six years, the patient's HPA axis failed to recover and she remained corticosteroid-dependent. Quarterly biochemical testing (after withholding hydrocortisone for 18 hours) consistently yielded undetectable serum cortisol and subnormal plasma ACTH levels. While she was on hydrocortisone 15 mg/day, mifepristone was initiated and gradually titrated to a maintenance dose of 600 mg/day after 5 months. Rapid recovery of the HPA axis was subsequently noted with ACTH rising into the supranormal range at 4 months followed by a subsequent rise in cortisol levels into the normal range. After 6 months, the dose of hydrocortisone and mifepristone was lowered and both were ultimately stopped after 8 months. The HPA axis remains normal after an additional 16 months of follow-up. Conclusion. Mifepristone successfully restored the HPA axis in a woman with prolonged secondary adrenal insufficiency (SAI) after adrenalectomy for Cushing's syndrome (CS).

  20. An FGF3-BMP Signaling Axis Regulates Caudal Neural Tube Closure, Neural Crest Specification and Anterior-Posterior Axis Extension.

    Directory of Open Access Journals (Sweden)

    Matthew J Anderson

    2016-05-01

    Full Text Available During vertebrate axis extension, adjacent tissue layers undergo profound morphological changes: within the neuroepithelium, neural tube closure and neural crest formation are occurring, while within the paraxial mesoderm somites are segmenting from the presomitic mesoderm (PSM. Little is known about the signals between these tissues that regulate their coordinated morphogenesis. Here, we analyze the posterior axis truncation of mouse Fgf3 null homozygotes and demonstrate that the earliest role of PSM-derived FGF3 is to regulate BMP signals in the adjacent neuroepithelium. FGF3 loss causes elevated BMP signals leading to increased neuroepithelium proliferation, delay in neural tube closure and premature neural crest specification. We demonstrate that elevated BMP4 depletes PSM progenitors in vitro, phenocopying the Fgf3 mutant, suggesting that excessive BMP signals cause the Fgf3 axis defect. To test this in vivo we increased BMP signaling in Fgf3 mutants by removing one copy of Noggin, which encodes a BMP antagonist. In such mutants, all parameters of the Fgf3 phenotype were exacerbated: neural tube closure delay, premature neural crest specification, and premature axis termination. Conversely, genetically decreasing BMP signaling in Fgf3 mutants, via loss of BMP receptor activity, alleviates morphological defects. Aberrant apoptosis is observed in the Fgf3 mutant tailbud. However, we demonstrate that cell death does not cause the Fgf3 phenotype: blocking apoptosis via deletion of pro-apoptotic genes surprisingly increases all Fgf3 defects including causing spina bifida. We demonstrate that this counterintuitive consequence of blocking apoptosis is caused by the increased survival of BMP-producing cells in the neuroepithelium. Thus, we show that FGF3 in the caudal vertebrate embryo regulates BMP signaling in the neuroepithelium, which in turn regulates neural tube closure, neural crest specification and axis termination. Uncovering this FGF3

  1. Chronic Lyme disease and the 'Axis of Evil'.

    Science.gov (United States)

    Stricker, Raphael B; Johnson, Lorraine

    2008-12-01

    Lyme disease is a controversial illness, and the existence of chronic Lyme disease induced by persistent infection with the Lyme spirochete, Borrelia burgdorferi, is the subject of continued debate. A recent publication defined the 'Axis of Evil' in this controversy as physicians who treat patients with needlessly prolonged courses of antibiotics, 'specialty laboratories' that perform 'inaccurate' Lyme testing and the internet, which promotes 'Lyme hysteria'. We examine the 'Axis of Evil' components in the context of diagnostic and therapeutic challenges for Lyme disease patients and their physicians, and we present an evidence-based refutation to this misguided view. Despite its virulent nature, the 'Axis of Evil' perspective is a useful starting point to resolve the controversy over Lyme disease.

  2. Microwave Bragg-scattering zone-axis-pattern analysis

    CERN Document Server

    Fraundorf, P; Garver, W; Freeman, M; Proctor, D

    2013-01-01

    Louis deBroglie's connection between momentum and spatial-frequency vectors is perhaps most viscerally-experienced via the real-time access that electron-diffraction provides to transverse slices of a crystal's reciprocal lattice. The classic introductory (and/or advanced) physics lab-experiment on microwave Bragg-scattering can with a bit of re-arrangement also give students access to "zone-axis-pattern" slices through the 3D spatial-frequency (i.e. reciprocal) lattice of a ball-bearing crystal. In this paper we show how data from the standard experimental set up can be used to generate zone-axis-patterns oriented down the crystal rotation-axis. This may be used to give students direct experience with crystal shape-transforms (which help to explain anomalous peaks), as well as to the complementary relation between non-Cartesian basis-vectors in direct and reciprocal (co-vector) space.

  3. Emergence of principal axis rotation in 110Ag

    International Nuclear Information System (INIS)

    The negative-parity yrast band of 110Ag has been extended significantly and the lifetimes of the high spin levels of this band have been measured. The experimentally observed level scheme and measured electromagnetic transition rates have been compared with the theoretical predictions of a model with two quasiparticles coupled to a triaxially deformed core. This calculation successfully reproduces the energy spectra and electromagnetic transition rates beyond Iπ=12-ℏ. These observations indicate that the principal axis of rotation is responsible for the generation of high angular momentum states along the yrast cascade in 110Ag. In all the other lighter isotopes, these states are generated through titled axis rotation. Thus, 110Ag is the first nucleus where the boundary between tilted and principal axis rotation could be established.

  4. Role of Met Axis in Head and Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yiru, E-mail: xuyiru@umich.edu; Fisher, Gary J., E-mail: xuyiru@umich.edu [Department of Dermatology, University of Michigan, Ann Arbor, MI 48109 (United States)

    2013-11-26

    Head and neck cancer is the sixth most common type of cancer worldwide. Despite advances in aggressive multidisciplinary treatments, the 5-year survival rate for this dreadful disease is only 50%, mostly due to high rate of recurrence and early involvement of regional lymph nodes and subsequent metastasis. Understanding the molecular mechanisms responsible for invasion and metastasis is one of the most pressing goals in the field of head and neck cancer. Met, also known as hepatocyte growth factor receptor (HGFR), is a member of the receptor protein tyrosine kinase (RPTK) family. There is compelling evidence that Met axis is dysregulated and plays important roles in tumorigenesis, progression, metastasis, angiogenesis, and drug resistance in head and neck cancer. We describe in this review current understanding of Met axis in head and neck cancer biology and development of therapeutic inhibitors targeting Met axis.

  5. Axis Patterning by BMPs: Cnidarian Network Reveals Evolutionary Constraints

    Directory of Open Access Journals (Sweden)

    Grigory Genikhovich

    2015-03-01

    Full Text Available BMP signaling plays a crucial role in the establishment of the dorso-ventral body axis in bilaterally symmetric animals. However, the topologies of the bone morphogenetic protein (BMP signaling networks vary drastically in different animal groups, raising questions about the evolutionary constraints and evolvability of BMP signaling systems. Using loss-of-function analysis and mathematical modeling, we show that two signaling centers expressing different BMPs and BMP antagonists maintain the secondary axis of the sea anemone Nematostella. We demonstrate that BMP signaling is required for asymmetric Hox gene expression and mesentery formation. Computational analysis reveals that network parameters related to BMP4 and Chordin are constrained both in Nematostella and Xenopus, while those describing the BMP signaling modulators can vary significantly. Notably, only chordin, but not bmp4 expression needs to be spatially restricted for robust signaling gradient formation. Our data provide an explanation of the evolvability of BMP signaling systems in axis formation throughout Eumetazoa.

  6. Chandra X-ray Observatory Optical Axis and Aimpoint

    Science.gov (United States)

    Zhao, Ping

    2016-01-01

    Chandra X-ray Observatory revolutionized the X-ray astronomy as being the first, and so far the only, X-ray telescope achieving sub-arcsecond resolution. Chandra comprises of three principal elements: the High Resolution Mirror Assembly (HRMA), Pointing Control and Aspect Determination (PCAD) system, and the Science Instrument Module (SIM). To achieve and retain the unprecedented imaging quality, it is critical that these three principal elements stay rigid and stable for the entire life time of the Chandra operation. Tracking the Chandra optical axis and aimpoint with respect to detector positions is the most relevant measurement for understanding telescope stability. The study shows that both the optical axis and the aimpoint has been drifting since Chandra launch. I will discuss the telescope focal-point, optical axis, aimpoint, their positiondrifts during the mission, the impact to Chandra operations, and the permanent default aimpoint, to be implemented in Chandra cycle 18.

  7. Small Vertical Axis Wind Turbines: aerodynamics and starting behavior

    Directory of Open Access Journals (Sweden)

    Horia DUMITRESCU

    2013-12-01

    Full Text Available In urban areas the wind is very turbulent and unstable with fast changes in direction andvelocity. In these environments, the use of small vertical axis wind turbines (VAWT becomesincreasingly attractive due to several advantages over horizontal axis wind turbines (HAWT.However, such designs have received much less attention than the more common propeller-typedesigns and the understanding of same aspects of their operation remains, to this day, incomplete.This is particularly true of their starting characteristics. Indeed, same authors heuristically maintainthat they cannot start without external assistance. This paper reviews the cause of the inability of thelow solidity fixed pitch vertical axis wind turbines to self-start, and investigates the way ofovercoming this draw back.

  8. Registration of the rotation axis in X-ray tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yimeng; Yang, Feifei; Hingerl, Ferdinand F.; Xiao, Xianghui; Liu, Yijin; Wu, Ziyu; Benson, Sally M.; Toney, Michael F.; Andrews, Joy C.; Pianetta, Piero A.

    2015-01-01

    There is high demand for efficient, robust and automated routines for tomographic data reduction, particularly for synchrotron data. Registration of the rotation axis in data processing is a critical step affecting the quality of the reconstruction and is not easily implemented with automation. Existing methods for calculating the center of rotation have been reviewed and an improved algorithm to register the rotation axis in tomographic data is presented. The performance of the proposed method is evaluated using synchrotron-based microtomography data on geological samples with and without artificial reduction of the signal-to-noise ratio. The proposed method improves the reconstruction quality by correcting both the tilting error and the translational offset of the rotation axis. The limitation of this promising method is also discussed.

  9. Observation of equilibria with a double magnetic axis in LHD

    International Nuclear Information System (INIS)

    Plasma shape control is a major knob to investigate confinement as well as MHD characteristics of magnetically confined plasmas. LHD has a large flexibility to explore a configuration effect by using 6 independent coil systems. Elongation can be controlled by a quadrupole field. Experimental observation of moderate elongation has shown that confinement is degraded gradually in both prolate (vertically elongated) and oblate (horizontally elongated) configurations. Since the rotational transform is weaker in the core region than in the periphery in LHD, a theoretical analysis suggests that excess quadrupole field results in split of the magnetic axis. Then the internal separatrix like petals emerges. Further application of quadrupole field eventually realizes a doublet configuration with a double magnetic axis bounded by this separatrix. An analytics suggests that split of the magnetic axis starts beyond elongation κ of 1.6 in the prolate case. The role of separatrix is attracting interest in effect on confinement performance as well as physics of unstable manifold, which has motivated strong shaping experiment in LHD. Both shaping of prolate and oblate directions has been explored for NBI heated plasmas. In the strongly prolate case, the doublet image has been observed by a tangential soft X-ray camera. Available profile measurements of temperature and density have not provided the 2-dimensional profile, however, assumption of concentric surfaces with a single magnetic axis seems to contradict with experimental observations in the 1-dimensional measurements in the case with strong shaping. This suggests the existence of doublet magnetic surfaces. These complex equilibria cannot be treated by the numerical code, ex. VMEC, with an assumption of nested flux surfaces with a single magnetic axis. Characteristics of these eccentric equilibria have been investigated by the HINT code which does not assume existence of nested flux surfaces. Experimental and computational

  10. Three axis vector atomic magnetometer utilizing polarimetric technique

    CERN Document Server

    Pradhan, Swarupananda

    2016-01-01

    The three axis magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only reflected signal from the polarimeter, thus can be easily expanded to make spatial array of detectors or / and high sensitivity field gradient measurement as required for biomedical application.

  11. Three axis vector atomic magnetometer utilizing polarimetric technique

    Science.gov (United States)

    Pradhan, Swarupananda

    2016-09-01

    The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity field gradient measurement as required for biomedical application.

  12. Efficient Path Query and Reasoning Method Based on Rare Axis

    Institute of Scientific and Technical Information of China (English)

    姜洋; 冯志勇; 王鑫马晓宁

    2015-01-01

    A new concept of rare axis based on statistical facts is proposed, and an evaluation algorithm is designed thereafter. For the nested regular expressions containing rare axes, the proposed algorithm can reduce its evaluation complexity from polynomial time to nearly linear time. The distributed technique is also employed to construct the navigation axis indexes for resource description framework (RDF) graph data. Experiment results in DrugBank and BioGRID show that this method can improve the query efficiency significantly while ensuring the accuracy and meet the query requirements on Web-scale RDF graph data.

  13. A three-axis ultrasensitive accelerometer for space

    Science.gov (United States)

    Bernard, A.

    A three-axis ultrasensitive accelerometer ASTRE (Accelerometre Spatial Triaxial Electrostatique) is a simplified version of the GRADIO accelerometer designed for the ARISTOTELES mission, which operates by measuring the force provided by a three-axis electrostatic suspension of the proof-mass. It covers the g-spectrum from 10 exp -8 to 10 exp -4 in the frequency range dc to 5 Hz. A dedicated test bench was developed in order to preserve the accelerometer from the seismic noise. The paper presents the performance parameters of the ASTRE accelerometer and some of the design schemes.

  14. Serotonergic stimulation of the rat hypothalamo-pituitary-adrenal axis

    DEFF Research Database (Denmark)

    Mikkelsen, Jens D; Hay-Schmidt, Anders; Kiss, Alexander

    2004-01-01

    Acute stimulation of the hypothalamo-pituitary-adrenal (HPA) axis by selective serotonin reuptake inhibitors (SSRIs) is mediated by several postsynaptic 5-HT receptor subtypes. Activation of 5-HT(1A) and 5-HT(2A) receptors increases plasma corticosterone levels, and it is likely that these receptor...... that the two serotonin receptor subtypes affect the HPA axis via a central target. In conclusion, 5-HT(1A) and 5-HT(2A) receptors regulate corticotrophin-releasing hormone (CRH) neurons via distinct but strongly interacting pathways, probably converging on the same neurons in the hypothalamus....

  15. Fast satellite prediction for four-axis telescopes

    Institute of Scientific and Technical Information of China (English)

    林钦畅

    1996-01-01

    The features of the method are as follows: Adopting an optimum average small arc to four-axis prediction,the azimuth and altitude of the tracking axis need not be adjusted during the same observation procedure.The prediction has been used for three different types of telescopes for many years and all demands of users have been satisfied.In this method,the prediction contents were more than others.Separating the unknowns,the actual equations for operation were concise,and the needed machine time was much less,even for the prediction of multistation.

  16. HIGH-SPEED 5-AXIS MACHINING FOR TOOLING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Saxer, M.

    2012-11-01

    Full Text Available In the modern metalworking industry, production moulds often have complex geometry, with undercut regions, small corner radii, sharp edges, deep cavities, or large cores. Conventional manufacturing process chains to machine these complex features are often lengthy and inefficient due to multiple steps. This article presents current results obtained through industry projects and experimental work using 5-axis high-speed machining with high-end CAD/CAM systems to improve process efficiency. Cost optimisation and lead time shortening can be clearly shown. This is of particular importance for South African manufacturing companies, where multi-axis HSC technology although not totally unknown is significantly under-used.

  17. Single Vector Calibration System for Multi-Axis Load Cells and Method for Calibrating a Multi-Axis Load Cell

    Science.gov (United States)

    Parker, Peter A. (Inventor)

    2003-01-01

    A single vector calibration system is provided which facilitates the calibration of multi-axis load cells, including wind tunnel force balances. The single vector system provides the capability to calibrate a multi-axis load cell using a single directional load, for example loading solely in the gravitational direction. The system manipulates the load cell in three-dimensional space, while keeping the uni-directional calibration load aligned. The use of a single vector calibration load reduces the set-up time for the multi-axis load combinations needed to generate a complete calibration mathematical model. The system also reduces load application inaccuracies caused by the conventional requirement to generate multiple force vectors. The simplicity of the system reduces calibration time and cost, while simultaneously increasing calibration accuracy.

  18. An improved computer controlled triple-axis neutron spectrometer

    International Nuclear Information System (INIS)

    A description is given of the computer-controlled triple-axis neutron spectrometer installed at the PLUTO reactor at Harwell. The reasons for an nature of recent major improvements are discussed. Following a general description of the spectrometer, details are then given of the new computerised control system, including the functions of the various programs which are now available to the user. (author)

  19. On lifting line analysis of horizontal axis windturbines

    Science.gov (United States)

    Politis, G. K.; Loukakis, T. A.

    A convergent iteration scheme for lifting line performance analysis of horizontal axis windturbines is presented. Lifting line correction factors are introduced and compared with those of Prandtl and Goldstein. Lifting line and strip theory formulations are applied for the calculation of performance for two windturbines. Differences of engineering importance are shown to exist in the prediction of the Power coefficient.

  20. Contribution to the method for determining femoral neck axis

    Directory of Open Access Journals (Sweden)

    Anđelković Zoran

    2014-01-01

    Full Text Available Introduction. Femoral neck axis plotting is of great significance in measuring parameters that define femoral head-neck junction sphericity in the group of patients with the femoroacetabular impingement. Literature methods of femoral neck axis determination have weaknesses associated with the risk of obtaining inaccurate values of certain parameters. Objective. Method of plotting of the femoral neck axis by two parallel lines that belong to the medial quarter of the femoral neck is proposed. Method was tested on the anatomic specimens and the respective radiograms. Methods. A total of 31 anatomic specimens of the proximal femur and respective radiographs were used, on which three axes of the femoral neck were plotted; accordingly, alpha angle value was determined and tested with corresponding parametric tests, with the measurement error of less than 5% and the strength of the applied tests of 80%. Results. Alpha angle values obtained by plotting femoral neck axis using the literature and methods we have proposed were not significantly different in our series, and, in more than a half of the specimens, the two axes overlapped each other. Conclusion. The advantage of the proposed method does not depend on the position of the femoral head rotation center in relation to the femoral neck, which favors proposed method for measuring the angles of femoral head sphericity in patients with the femoral head translation. Disadvantage of the study is a small sample size for valid conclusions about the applicability of this method in clinical practice.

  1. On the Turbulent Mixing in Horizontal Axis Wind Turbine Wakes

    NARCIS (Netherlands)

    Lignarolo, L.E.M.

    2016-01-01

    The wake flow of a horizontal axis wind turbine is characterised by lower wind speed and higher turbulence than the free-stream conditions. When clustered in large wind farms, wind turbines regularly operate inside the wake of one or more upstream machines. This is a major cause of energy production

  2. Tilted axis rotation in odd-odd {sup 164}Tm

    Energy Technology Data Exchange (ETDEWEB)

    Reviol, W.; Riedinger, L.L.; Wang, X.Z.; Zhang, J.Y. [Univ. of Tennessee, Knoxville, TN (United States)] [and others

    1996-12-31

    Ten band structures are observed in {sup 164}Tm, among them sets of parallel and anti-parallel couplings of the proton and neutron spins. The Tilted Axis Cranking scheme is applied for the first time to an odd-odd nucleus in a prominent region of nuclear deformation.

  3. Stereo PIV Experiments on Horizontal Axis Wind Turbine Rotor Model

    NARCIS (Netherlands)

    Akay, B.; Micallef, D.; Ferreira, C.S.; Van Bussel, G.J.W.

    2011-01-01

    This paper sets out to describe the measurements and computations to construct three components of velocity field around the blade. The primary aim of the measurements was to gain insight into the physics of the flow field produced by a horizontal axis wind turbine-HAWT blade. Stereo Particle Image

  4. Hypothalamic pituitary adrenal axis and prolactin abnormalities in suicidal behavior.

    Science.gov (United States)

    Pompili, Maurizio; Serafini, Gianluca; Palermo, Mario; Seretti, Maria Elena; Stefani, Henry; Angeletti, Gloria; Lester, David; Amore, Mario; Girardi, Paolo

    2013-11-01

    Hypothalamic-Pituitary-Adrenal (HPA) axis hyperactivity measured with the dexamethasone suppression test and the dexamethesone/CRH test may have some predictive power for suicidal behavior in patients with mood disorders. Increased prolactin (PRL) levels may be related both to physiological and pathological conditions. HPA-axis abnormalities and increased levels of PRL may coexist, and common neuroendocrine changes may activate both HPA axis and PRL release. HPA-axis hyperactivity is presumably present in a large subpopulation of depressed subjects. Suicidal behavior is considered to be a form of inward-directed aggression, and aggressive behavior has been connected to high androgen levels. However, lower plasma total testosterone levels have also been reported in subjects with depression and higher suicidality. Lipid/immune dysregulations, the increased ratio of blood fatty acids, and increased PRL levels may each be associated with the increased production of pro-inflammatory cytokines, which have been reported in patients with major depression and patients engaging in suicidal behavior. Although no studies have been done to determine whether ante-mortem physical stress may be detected by raised post-mortem PRL, this would be of great interest for physicians.

  5. Locating an axis-parallel rectangle on a Manhattan plane

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Körner, Mark-Christoph;

    2014-01-01

    In this paper we consider the problem of locating an axis-parallel rectangle in the plane such that the sum of distances between the rectangle and a finite point set is minimized, where the distance is measured by the Manhattan norm 1. In this way we solve an extension of the Weber problem...

  6. Survey of Unsteady Computational Aerodynamics for Horizontal Axis Wind Turbines

    Science.gov (United States)

    Frunzulicǎ, F.; Dumitrescu, H.; Cardoş, V.

    2010-09-01

    We present a short review of aerodynamic computational models for horizontal axis wind turbines (HAWT). Models presented have a various level of complexity to calculate aerodynamic loads on rotor of HAWT, starting with the simplest blade element momentum (BEM) and ending with the complex model of Navier-Stokes equations. Also, we present some computational aspects of these models.

  7. DARHT Axis-I Diode Simulations II: Geometrical Scaling

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Carl A. Jr. [Los Alamos National Laboratory

    2012-06-14

    Flash radiography of large hydrodynamic experiments driven by high explosives is a venerable diagnostic technique in use at many laboratories. Many of the largest hydrodynamic experiments study mockups of nuclear weapons, and are often called hydrotests for short. The dual-axis radiography for hydrodynamic testing (DARHT) facility uses two electron linear-induction accelerators (LIA) to produce the radiographic source spots for perpendicular views of a hydrotest. The first of these LIAs produces a single pulse, with a fixed {approx}60-ns pulsewidth. The second axis LIA produces as many as four pulses within 1.6-{micro}s, with variable pulsewidths and separation. There are a wide variety of hydrotest geometries, each with a unique radiographic requirement, so there is a need to adjust the radiographic dose for the best images. This can be accomplished on the second axis by simply adjusting the pulsewidths, but is more problematic on the first axis. Changing the beam energy or introducing radiation attenuation also changes the spectrum, which is undesirable. Moreover, using radiation attenuation introduces significant blur, increasing the effective spot size. The dose can also be adjusted by changing the beam kinetic energy. This is a very sensitive method, because the dose scales as the {approx}2.8 power of the energy, but it would require retuning the accelerator. This leaves manipulating the beam current as the best means for adjusting the dose, and one way to do this is to change the size of the cathode. This method has been proposed, and is being tested. This article describes simulations undertaken to develop scaling laws for use as design tools in changing the Axis-1 beam current by changing the cathode size.

  8. Analytical Aerodynamic Simulation Tools for Vertical Axis Wind Turbines

    International Nuclear Information System (INIS)

    Wind power is a renewable energy source that is today the fastest growing solution to reduce CO2 emissions in the electric energy mix. Upwind horizontal axis wind turbine with three blades has been the preferred technical choice for more than two decades. This horizontal axis concept is today widely leading the market. The current PhD thesis will cover an alternative type of wind turbine with straight blades and rotating along the vertical axis. A brief overview of the main differences between the horizontal and vertical axis concept has been made. However the main focus of this thesis is the aerodynamics of the wind turbine blades. Making aerodynamically efficient turbines starts with efficient blades. Making efficient blades requires a good understanding of the physical phenomena and effective simulations tools to model them. The specific aerodynamics for straight bladed vertical axis turbine flow are reviewed together with the standard aerodynamic simulations tools that have been used in the past by blade and rotor designer. A reasonably fast (regarding computer power) and accurate (regarding comparison with experimental results) simulation method was still lacking in the field prior to the current work. This thesis aims at designing such a method. Analytical methods can be used to model complex flow if the geometry is simple. Therefore, a conformal mapping method is derived to transform any set of section into a set of standard circles. Then analytical procedures are generalized to simulate moving multibody sections in the complex vertical flows and forces experienced by the blades. Finally the fast semi analytical aerodynamic algorithm boosted by fast multipole methods to handle high number of vortices is coupled with a simple structural model of the rotor to investigate potential aeroelastic instabilities. Together with these advanced simulation tools, a standard double multiple streamtube model has been developed and used to design several straight bladed

  9. Velocity measurement of model vertical axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.A.; McWilliam, M. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering

    2006-07-01

    An increasingly popular solution to future energy demand is wind energy. Wind turbine designs can be grouped according to their axis of rotation, either horizontal or vertical. Horizontal axis wind turbines have higher power output in a good wind regime than vertical axis turbines and are used in most commercial class designs. Vertical axis Savonius-based wind turbine designs are still widely used in some applications because of their simplistic design and low wind speed performance. There are many design variables that must be considered in order to optimize the power output in a given wind regime in a typical wind turbine design. Using particle image velocimetry, a study of the air flow around five different model vertical axis wind turbines was conducted in a closed loop wind tunnel. A standard Savonius design with two semi-circular blades overlapping, and two variations of this design, a deep blade and a shallow blade design were among the turbine models included in this study. It also evaluated alternate designs that attempt to increase the performance of the standard design by allowing compound blade curvature. Measurements were collected at a constant phase angle and also at random rotor orientations. It was found that evaluation of the flow patterns and measured velocities revealed consistent and stable flow patterns at any given phase angle. Large scale flow structures are evident in all designs such as vortices shed from blade surfaces. An important performance parameter was considered to be the ability of the flow to remain attached to the forward blade and redirect and reorient the flow to the following blade. 6 refs., 18 figs.

  10. DESIGN NOTE: A low interaction two-axis wind tunnel force balance designed for large off-axis loads

    Science.gov (United States)

    Ostafichuk, Peter M.; Green, Sheldon I.

    2002-10-01

    A novel two-axis wind tunnel force balance using air bushings for off-axis load compensation has been developed. The design offers a compact, robust, and versatile option for precisely measuring horizontal force components irrespective of vertical and moment loads. Two independent stages of cylindrical bushings support large moments and vertical force; there is low interaction due to the minimal friction along the horizontal measurement axes. The current design measures drag and side forces up to 70 N and can safely operate in the presence of vertical loads as large as 2200 N and moment loads up to 425, 750, and 425 N m in roll, pitch, and yaw, respectively. Eleven drag axis calibration trials were conducted with a variety of applied vertical forces and pitching moments. The individual linear calibration slopes for the trials agreed to within 0.18% and the largest residual from all calibrations was 0.38% of full scale. As the residuals were found to obey a normal distribution, with 99% certainty the expected drag resolution of the device is better than 0.30% of full scale, independent of off-axis loads.

  11. Psychiatric Axis I Comorbidities among Patients with Gender Dysphoria

    Directory of Open Access Journals (Sweden)

    Azadeh Mazaheri Meybodi

    2014-01-01

    Full Text Available Objectives. Cooccurring psychiatric disorders influence the outcome and prognosis of gender dysphoria. The aim of this study is to assess psychiatric comorbidities in a group of patients. Methods. Eighty-three patients requesting sex reassignment surgery (SRS were recruited and assessed through the Persian Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I. Results. Fifty-seven (62.7% patients had at least one psychiatric comorbidity. Major depressive disorder (33.7%, specific phobia (20.5%, and adjustment disorder (15.7% were the three most prevalent disorders. Conclusion. Consistent with most earlier researches, the majority of patients with gender dysphoria had psychiatric Axis I comorbidity.

  12. Off-axis Fresnel numbers in laser systems

    Institute of Scientific and Technical Information of China (English)

    Yudong; Yao; Junyong; Zhang; Yanli; Zhang; Qunyu; Bi; Jianqiang; Zhu

    2014-01-01

    The physical meaning and essence of Fresnel numbers are discussed,and two definitions of these numbers for offaxis optical systems are proposed.The universal Fresnel number is found to be N =(a2/λz) * C1+ C2.The Rayleigh–Sommerfeld nonparaxial diffraction formula states that a simple analytical formula for the nonparaxial intensity distribution after a circular aperture can be obtained.Theoretical derivations and numerical calculations reveal that the first correction factor C1 is equal to cos θ and the second factor C2 is a function of the incident wavefront and the shape of the diffractive aperture.Finally,some diffraction phenomena in off-axis optical systems are explained by the off-axis Fresnel number.

  13. Early programming of the IGF-I axis

    DEFF Research Database (Denmark)

    Larnkjær, Anni; Ingstrup, Helga Kristensen; Schack-Nielsen, Lene;

    2009-01-01

    -I production. Conversely, studies suggest that later in childhood, those breastfed are taller and have higher IGF-I levels. Therefore, it has been suggested that the IGF-I axis may be programmed by diet during infancy. The association between IGF-I in infancy and later life is not known. OBJECTIVE: To examine......BACKGROUND: IGF-I is a major regulator of growth, influenced primarily by diet in infancy and primarily by GH in childhood. Breastfed infants have lower IGF-I levels compared to formula fed and tend to be shorter. The higher protein content of infant formula has a stimulatory effect on IGF......=-0.26, P=0.043, and n=109). CONCLUSION: The results support the hypothesis that the IGF-I axis can be programmed early in life....

  14. Electrostatic levitation under the single-axis feedback control condition

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An electrostatic levitator with a single-axis feedback control system was developed on the basis of electric field analysis and optimum design for levitation electrodes. In order to realize the stable levitation of various types of materials such as metals, inorganic materials and polymers, we made both experimental and theoretical investigations to solve the four key problems of electric field optimization, sample position detecting, sample charging control and levitation voltage minimization. Under the capacitive induction charging condition, a sample with the size of 2.6–4.5 mm usually bears positive charges amounting to 10-9 Coulomb. Because the single-axis feedback control system responds quickly, it takes the levitated sample only 0.1 s from leaving the bottom electrode until attaining a stable levitation in the upright direction. The levitated sample displays satisfactory levitation stability in both the upright and the horizontal directions owing to the constraining force produced by spherical electrodes.

  15. Tuning the DARHT Axis-II linear induction accelerator focusing

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Carl A. [Los Alamos National Laboratory

    2012-04-24

    Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST) to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an

  16. A new vertical axis wind turbine design for urban areas

    Science.gov (United States)

    Frunzulica, Florin; Cismilianu, Alexandru; Boros, Alexandru; Dumitrache, Alexandru; Suatean, Bogdan

    2016-06-01

    In this paper we aim at developing the model of a Vertical Axis Wind Turbine (VAWT) with the short-term goal of physically realising this turbine to operate at a maximmum power of 5 kW. The turbine is designed for household users in the urban or rural areas and remote or isolated residential areas (hardly accsessible). The proposed model has a biplane configuration on each arm of the VAWT (3 × 2 = 6 blades), allowing for increased performance of the turbine at TSR between 2 and 2.5 (urban area operation) compared to the classic vertical axis turbines. Results that validate the proposed configuration as well as passive control methods to increase the performance of the classic VAWTs are presented.

  17. Summary of tower designs for large horizontal axis wind turbines

    Science.gov (United States)

    Frederick, G. R.; Savino, J. M.

    1986-01-01

    Towers for large horizontal axis wind turbines, machines with a rotor axis height above 30 meters and rated at more than 500 kW, have varied in configuration, materials of construction, type of construction, height, and stiffness. For example, the U.S. large HAWTs have utilized steel truss type towers and free-standing steel cylindrical towers. In Europe, the trend has been to use only free-standing and guyed cylindrical towers, but both steel and reinforced concrete have been used as materials of construction. These variations in materials of construction and type of construction reflect different engineering approaches to the design of cost effective towers for large HAWTs. Tower designs are the NASA/DOE Mod-5B presently being fabricated. Design goals and requirements that influence tower configuration, height and materials are discussed. In particular, experiences with United States large wind turbine towers are elucidated. Finally, current trends in tower designs for large HAWTs are highlighted.

  18. Development of the adrenal axis in the neonatal rat

    Energy Technology Data Exchange (ETDEWEB)

    Guillet, Ronnie

    1977-01-01

    Plasma corticosterone and ACTH concentrations were determined in neonatal rats 1, 7, 14, and 21 days old, under a variety of experimental conditions, to obtain more information on the postnatal development of the rat hypothalamo-adrenal (HHA) axis. The results indicate that: (1) there is a diminution followed by an increase in responsiveness of the adrenal gland, but the pituitary response to direct hormonal stimulation is unchanged during the first three postnatal weeks; (2) continued stimulation of the adrenal by ACTH or of the central nervous system (CNS) or hypothalamus by corticosterone is necessary during early postnatal development to allow normal maturation of the HHA axis; and (3) feedback inhibition is operative by birth, at least to a moderate degree. Taken together, the studies suggest that both the adrenal and pituitary glands are potentially functional at birth, but that the hypothalamic and CNS mediators of the stress response are not mature until at least the second or third postnatal week. (ERB)

  19. Jet maximization, axis minimization, and stable cone finding

    Science.gov (United States)

    Thaler, Jesse

    2015-10-01

    Jet finding is a type of optimization problem, where hadrons from a high-energy collision event are grouped into jets based on a clustering criterion. As three interesting examples, one can form a jet cluster that (i) optimizes the overall jet four-vector, (ii) optimizes the jet axis, or (iii) aligns the jet axis with the jet four-vector. In this paper, we show that these three approaches to jet finding, despite being philosophically quite different, can be regarded as descendants of a mother optimization problem. For the special case of finding a single cone jet of fixed opening angle, the three approaches are genuinely identical when defined appropriately, and the result is a stable cone jet with the largest value of a quantity J . This relationship is only approximate for cone jets in the rapidity-azimuth plane, as used at the Large Hadron Collider, though the differences are mild for small radius jets.

  20. Effects of structure flexibility on horizontal axis wind turbine performances

    Science.gov (United States)

    Coiro, D. P.; Daniele, E.; Scherillo, F.

    2013-10-01

    This work illustrates the effects of flexibility of rotor blades and turbine tower on the performances of an horizontal axis wind turbine (HAWT) designed by our ADAG research group, by means of several example applied on a recent project for a active pitch controlled upwind 60 kW HAWT. The influence of structural flexibility for blade only, tower only and blade coupled with tower configuration is investigated using an aero-elastic computer-aided engineering (CAE) tool for horizontal axis wind turbines named FAST developed at National Renewable Energy Laboratory (NREL) of USA. For unsteady inflow conditions in front of the isolated HAWT the performances in rigid and flexible operation mode are computed and compared in order to illustrate the limitation included within a classical rigid body approach to wind turbine simulation.

  1. Social Deprivation and the HPA Axis in Early Development

    OpenAIRE

    Koss, Kalsea J; Hostinar, Camelia E.; Donzella, Bonny; Gunnar, Megan R.

    2014-01-01

    Growing evidence suggests that early social deprivation impacts the activity of the hypothalamic-pituitary-adrenocortical axis. Early adverse care in the form of institutional or orphanage care provides a human model for early social deprivation. The present study examined changes in diurnal cortisol during the transition to family care in the first two years post-adoption. Children adopted between 15 and 36 months from institutional care were examined four times during thei...

  2. Semiactive Vibration Control for Horizontal Axis Washing Machine

    Directory of Open Access Journals (Sweden)

    Barış Can Yalçın

    2015-01-01

    Full Text Available A semiactive vibration control method is developed to cope with the dynamic stability problem of a horizontal axis washing machine. This method is based on adjusting the maximum force values produced by the semiactive suspension elements considering a washing machine’s vibration data (three axis angular position and three axis angular acceleration values in time. Before actuation signals are received by the step motors of the friction dampers, vibration data are evaluated, and then, the step motors start to narrow or expand the radius of bracelets located on the dampers. This changes the damping properties of the damper in the suspension system, and thus, the semiactive suspension system absorbs unwanted vibrations and contributes to the dynamic stability of the washing machine. To evaluate the vibration data, the angular position and angular acceleration values in three axes are defined in a function, and the maximum forces produced by semiactive suspension elements are calculated according to the gradient of this function. The relation between the dynamic stability and the walking stability is also investigated. A motion (gyroscope and accelerometer sensor is installed on the top-front panel of the washing machine because a mathematical model of a horizontal axis washing machine suggests that the walking behavior starts around this location under some assumptions, and therefore, calculating the vibrations occurring there is crucial. Semiactive damping elements are located under the left and right sides of the tub. The proposed method is tested during the spinning cycle of washing machine operation, increasing gradually from 200 rpm to 900 rpm, which produces the most challenging vibration patterns for dynamic stability. Moreover, the sound power levels produced by the washing machine are measured to evaluate the noise performance of the washing machine while the semiactive suspension system is controlled. The effectiveness of the

  3. Development of Rotary Axis for Wire Electrical Discharge Machining (WEDM)

    OpenAIRE

    M. Parthiban, C. Manigandan, G. Muthu Venkadesh, M. Ranjith Kumar

    2013-01-01

    This paper gives an overview of setting up a rotary axis to the existing WEDM machine to investigate the machining parameters in WEDG of harder materials. There are a number of hybrid machining processes (HMPs) seeking the combined advantage of EDM and other machining techniques. One such combination is wire electrical discharge grinding (WEDG), which is commonly used for micro-machining of fine and hard rods. WEDG employs a single wire guide to confine the wir...

  4. Vertical axis wind turbine in a falling soap film

    OpenAIRE

    Araya, Daniel B.; Dabiri, John O.

    2015-01-01

    Vertical axis wind turbines (VAWTs) have demonstrated a potential to significantly enhance the efficiency of energy harvesting within a wind farm. One mechanism that contributes to this enhancement is a VAWT’s inherent insensitivity to wind direction coupled with blockage within an array of turbines. Much like the flow around a bluff body, turbine blockage can locally accelerate the flow near one turbine, providing faster inflow conditions for a well-placed neighboring turbine. Since the powe...

  5. 6-Axis Force/Moment Sensor In Humanoid Robot Foot

    Science.gov (United States)

    Ai-Faifi, Badrih; Al-Shammary, Maryam; Al-Shehry, Zinab

    2014-07-01

    The foot is the most Important part of the humanoid .Thought the sensor of the robot can understand the environment In which they live, it is important to developed an intelligent foot. In order to walk on uneven terrain safely this poster describes an intelligent foot with 6- axis force/moment sensors for humanoid robot that is one of the solution that can help the robot to walk in uneven terrain safely.

  6. Inversion of the chordate body axis: are there alternatives?

    Science.gov (United States)

    Gerhart, J.

    2000-01-01

    One major morphological difference between chordates and annelids or arthropods is the opposite orientation of the nerve cord and heart. A long-standing proposal is that the chordate axis evolved by inverting the body of an ancestor with the annelid/arthropod orientation. However, the data can also be explained by a common ancestor with diffuse dorsoventral organization, followed by oppositely directed condensation of the nerve cord and relocation of the heart in the two lines.

  7. Inversion of the chordate body axis: Are there alternatives?

    OpenAIRE

    Gerhart, J.

    2000-01-01

    One major morphological difference between chordates and annelids or arthropods is the opposite orientation of the nerve cord and heart. A long-standing proposal is that the chordate axis evolved by inverting the body of an ancestor with the annelid/arthropod orientation. However, the data can also be explained by a common ancestor with diffuse dorsoventral organization, followed by oppositely directed condensation of the nerve cord and relocation of the heart in the t...

  8. Bendability optimization of flexible optical nanoelectronics via neutral axis engineering

    OpenAIRE

    Lee, Sangmin; Kwon, Jang-Yeon; Yoon, Daesung; Cho, Handong; You, Jinho; Kang, Yong Tae; Choi, Dukhyun; Hwang, Woonbong

    2012-01-01

    The enhancement of bendability of flexible nanoelectronics is critically important to realize future portable and wearable nanoelectronics for personal and military purposes. Because there is an enormous variety of materials and structures that are used for flexible nanoelectronic devices, a governing design rule for optimizing the bendability of these nanodevices is required. In this article, we suggest a design rule to optimize the bendability of flexible nanoelectronics through neutral axi...

  9. The reno-pineal axis: A novel role for melatonin

    OpenAIRE

    Sanjay Kalra; Swati Agrawal; Manisha Sahay

    2012-01-01

    The pineal gland is a tiny endocrine gland whose physiologic role has been the focus of much research and much more speculation over the past century. This mini-review discusses recent findings which correlate melatonin and renal physiology, and postulates the presence of a “reno-pineal axis.” Drawing lessons from comparative endocrinology, while quoting human data, it advocates the need to study the “reno-pineal axis” in greater detail.

  10. Neuropeptides and the Microbiota-Gut-Brain Axis

    OpenAIRE

    Holzer, Peter; Farzi, Aitak

    2014-01-01

    Neuropeptides are important mediators both within the nervous system and between neurons and other cell types. Neuropeptides such as substance P, calcitonin gene-related peptide and neuropeptide Y (NPY), vasoactive intestinal polypeptide, somatostatin and corticotropin-releasing factor are also likely to play a role in the bidirectional gut-brain communication. In this capacity they may influence the activity of the gastrointestinal microbiota and its interaction with the gut-brain axis. Curr...

  11. Resonance Shift of Single-Axis Acoustic Levitation

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Jun; WEI Bing-Bo

    2007-01-01

    @@ The resonance shift due to the presence and movement of a rigid spherical sample in a single-axis acoustic levitator is studied with the boundary element method on the basis of a two-cylinder model of the levitator.The introduction of a sample into the sound pressure nodes, where it is usually levitated, reduces the resonant interval Hn (n is the mode number) between the reflector and emitter.

  12. Design, Operation and Diagnostics of a Vertical Axis Wind Turbine

    OpenAIRE

    Colley, Gareth

    2012-01-01

    The need for sustainable energy sources becomes greater each year due to the continued depletion of fossil fuels and the resulting energy crisis. Solutions to this problem are potentially in the form of wind turbines which have been receiving increased support at a micro level. At present a number of wind turbines are being developed that are of cross-flow vertical axis operation which have shown significant increases in performance compared to existing technologies. From an extensive literat...

  13. Plasma Transport at Magnetic Axis in Toroidal Confinement System

    Institute of Scientific and Technical Information of China (English)

    WANGZhongtian

    2001-01-01

    The particle orbits which intersect the magnetic axis behave differently from banana ones, referred to as potato orbits. The potential importance on tokamak transport is emphasized by Politzer, Lin, Tang, and Lee,and Shaing, Hazeltine, and Zarnstoff. However, there are many problems in the lasttwo papers. For example, the Eq. (48) in Ref. [5] should satisfy the orbit constraint which guarantees single value of the function go, that is, solubility condition, and Eq. (8) in Ref. [6] has the same problem.

  14. CFD Simulation of Twin Vertical Axis Tidal Turbines System

    OpenAIRE

    Syed Shah Khalid; Zhang Liang; Sheng Qi-hu

    2013-01-01

    As concerns about rising fossil-fuel prices, energy security and climate-change increase, renewable energy can play a vital role in producing local, clean and inexhaustible energy to supply world rising demand for electricity. In this study, hydrodynamic analysis of vertical axis tidal turbine operating side-by-side is numerically analyzed. Two-dimensional numerical modeling of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX; this is based on a ...

  15. ACE2-Ang(1-7) axis in vascular function

    Institute of Scientific and Technical Information of China (English)

    HUANG Yu

    2016-01-01

    Angiotensin-converting enzyme 2 (ACE2)-angiotensin (1-7) [Ang (1-7)]-Mas constitutes the vasoprotective axis and is demon-strated to antagonize the vascular pathophysiological effects of the classical renin -angiotensin system .We hypothesize that upregulation of ACE2-Ang (1-7) signaling protects endothelial function through reducing oxidative stress , thus resulting in beneficial outcome in di-abetes.Ex vivo treatment with Ang (1-7) augmented endothelium-dependent relaxation (EDR) in renal arteries from diabetic patients . Both Ang (1-7) infusion via osmotic pump (500 ng・ kg -1・ min-1 ) for 2 weeks and exogenous ACE 2 overexpression mediated by ad-enoviral ACE2 via tail vein injection rescued the impaired EDR and flow-mediated dilatation ( FMD) in db/db mice.Diminazene acetu-rate treatment (15 mg・ kg-1・ d-1 ) activated ACE2, increased the circulating Ang (1-7) level, and augmented EDR and FMD in db/db mouse arteries.In addition, activation of the ACE2-Ang (1-7) axis reduced reactive oxygen species (ROS) overproduction de-termined by dihydroethidium staining , CM-H2DCFDA fluorescence imaging , and chemiluminescence assay in db/db mouse aortas and also in high-glucose-treated endothelial cells .Pharmacological benefits of ACE 2-Ang ( 1-7 ) upregulation on endothelial function were confirmed in ACE2 knockout mice both ex vivo and in vitro.We elucidate that the ACE2-Ang (1-7)-Mas axis serves as an important signal pathway in endothelial cell protection in diabetic mice , especially in diabetic human arteries .In summary, endogenous ACE2-Ang (1-7) activation or ACE2 overexpression preserves endothelial function in diabetic mice through increasing nitric oxide bioavail -ability and inhibiting oxidative stress , suggesting the therapeutic potential of ACE 2-Ang(1-7) axis activation against diabetic vasculop-athy.

  16. Neuropeptides and the microbiota-gut-brain axis.

    Science.gov (United States)

    Holzer, Peter; Farzi, Aitak

    2014-01-01

    Neuropeptides are important mediators both within the nervous system and between neurons and other cell types. Neuropeptides such as substance P, calcitonin gene-related peptide and neuropeptide Y (NPY), vasoactive intestinal polypeptide, somatostatin and corticotropin-releasing factor are also likely to play a role in the bidirectional gut-brain communication. In this capacity they may influence the activity of the gastrointestinal microbiota and its interaction with the gut-brain axis. Current efforts in elucidating the implication of neuropeptides in the microbiota-gut-brain axis address four information carriers from the gut to the brain (vagal and spinal afferent neurons; immune mediators such as cytokines; gut hormones; gut microbiota-derived signalling molecules) and four information carriers from the central nervous system to the gut (sympathetic efferent neurons; parasympathetic efferent neurons; neuroendocrine factors involving the adrenal medulla; neuroendocrine factors involving the adrenal cortex). Apart from operating as neurotransmitters, many biologically active peptides also function as gut hormones. Given that neuropeptides and gut hormones target the same cell membrane receptors (typically G protein-coupled receptors), the two messenger roles often converge in the same or similar biological implications. This is exemplified by NPY and peptide YY (PYY), two members of the PP-fold peptide family. While PYY is almost exclusively expressed by enteroendocrine cells, NPY is found at all levels of the gut-brain and brain-gut axis. The function of PYY-releasing enteroendocrine cells is directly influenced by short chain fatty acids generated by the intestinal microbiota from indigestible fibre, while NPY may control the impact of the gut microbiota on inflammatory processes, pain, brain function and behaviour. Although the impact of neuropeptides on the interaction between the gut microbiota and brain awaits to be analysed, biologically active peptides

  17. Multi axis differential optical absorption spectroscopy (MAX-DOAS)

    OpenAIRE

    Hönninger, G.; C. von Friedeburg; U. Platt

    2004-01-01

    Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) in the atmosphere is a novel measurement technique that represents a significant advance on the well-established zenith scattered sunlight DOAS instruments which are mainly sensitive to stratospheric absorbers. MAX-DOAS utilizes scattered sunlight received from multiple viewing directions. The spatial distribution of various trace gases close to the instrument can be derived by combining several viewing directions. Ground...

  18. Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS)

    OpenAIRE

    Hönninger, G.; Friedeburg, C.; U. Platt

    2003-01-01

    Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) in the atmosphere is a novel measurement technique that represents a significant advance on the well-established zenith scattered sunlight DOAS instruments which are mainly sensitive to stratospheric absorbers. MAX-DOAS utilizes scattered sunlight received from multiple viewing directions. The spatial distribution of various trace gases close to the instrument can be derived by combining sev...

  19. Estimation of power in low velocity vertical axis wind turbine

    Science.gov (United States)

    Sampath, S. S.; Shetty, Sawan; Chithirai Pon Selvan, M.

    2015-06-01

    The present work involves in the construction of a vertical axis wind turbine and the determination of power. Various different types of turbine blades are considered and the optimum blade is selected. Mechanical components of the entire setup are built to obtain maximum rotation per minute. The mechanical energy is converted into the electrical energy by coupling coaxially between the shaft and the generator. This setup produces sufficient power for consumption of household purposes which is economic and easily available.

  20. Study of axis-symmetry for judgement on nuclear parts

    International Nuclear Information System (INIS)

    In this paper, gamma-ray distributions from nuclear weapon parts of different shapes are simulated. The gamma-rays from a cylinder nuclear part have axis-symmetry distribution, while the gamma-rays from prism nuclear parts are of asymmetry distribution. The quadra- and penta-prism distributions differ obviously from that of the cylinder. However, the asymmetry of hexa-, octo- and dodeca-prism reduces gradually to approach to the symmetry distribution of the cylinder. (authors)

  1. Noise estimation for off-axis electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Röder, Falk, E-mail: Falk.Roeder@Triebenberg.de [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Lubk, Axel; Wolf, Daniel [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Niermann, Tore [Institut für Optik und Atomare Physik, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany)

    2014-09-15

    Off-axis electron holography provides access to the phase of the elastically scattered wave in a transmission electron microscope at scales ranging from several hundreds of nanometres down to 0.1 nm. In many cases the reconstructed phase shift is directly proportional to projected electric and magnetic potentials rendering electron holography a useful and established characterisation method for materials science. However, quantitative interpretation of experimental phase shifts requires quantitative knowledge about the noise, which has been previously established for some limiting cases only. Here, we present a general noise transfer formalism for off-axis electron holography allowing to compute the covariance (noise) of reconstructed amplitude and phase from characteristic detector functions and general properties of the reconstruction process. Experimentally, we verify the presented noise transfer formulas for two different cameras with and without objects within the errors given by the experimental noise determination. - Highlights: • We derive a general noise transfer for the off-axis holographic reconstruction. • Noise transfer formulas given by F. Lenz are included as a special case. • We estimate the covariance of a hologram using the noise spread function. • We experimentally verify the derived noise transfer formulas.

  2. Moving Object Detection Using Graph’s Axis Change Method

    Directory of Open Access Journals (Sweden)

    Gagandeep Kaur

    2012-03-01

    Full Text Available The detection and identify moving objects in a video sequence is very important concept. The currently available techniques for motion estimation can be broadly categorized into main classes: block matching methods and optical flow methods. But here detection of moving objects is detected by using Graph’s axis change method. Here we convert the image in to pixels and then calculate the values when the pixel change its position according to x axis and y axis. There is no problem of fixed and movable background. This paper investigates the different motion estimation algorithms used for video processing applications. Among the available motion estimation methods, the Lucas kanade Algorithm using changed axis’s method has been used in this paper for detection of moving objects in a video sequence. The algorithm produces the result of Horizontal and Vertical components velocity, u and v respectively. This velocity is measured in the form of vectors and has been used to segment the moving objects from the video sequence. The algorithm has been applied to different sets of synthetic and real video sequence.

  3. Calibration of rotary joints in multi-axis machine tools

    Science.gov (United States)

    Khan, Abdul Wahid; Liu, Fei; Chen, Wuyi

    2009-05-01

    A novel technique is developed and implemented for error quantification in a rotary joint of a multi-axis machine tool by using a calibrated double ball bar (DBB) system as a working standard. This technique greatly simplified the measurement setup requirement and accelerated the calibration of rotary joints. In addition it is highly economical by reducing the complex optics and eliminating the usage of various tooling, instrumentation and accessories. This methodology is capable of measuring the five degree of freedom (DOF) errors out of 6DOF of a rotary joint by using the calibrated DBB system and a point locating fixture. The methodology is implemented on rotary joints of a five axis CNC machine tools. Equation solvers and error modeling technique are implemented and validity of the methodology and authenticity of the results obtained are tested through simulation in UG and Matlab software. The methodology is found extremely feasible pragmatic, quite simple, efficient and easy to use for error characterization of rotary joints of multi axis machine tools.

  4. A Dual-Axis Electrostatically Driven MEMS Microgripper

    Directory of Open Access Journals (Sweden)

    Yukun Jia

    2014-11-01

    Full Text Available This paper presents the design of a new monolithic two- axis electrostatically actuated MEMS microgripper with integrated capacitive position and force sensors working at the micro-scale level. Each of the two jaws of the micro‐ gripper possesses two degrees-of-freedom (DOF and is capable of positioning in both x-and y-axes. Unlike existing works, where one gripper arm is actuated and other one is sensed, both arms of the proposed microgripper are actuated and sensed independently. A sensing scheme is constructed to provide the position and force signals in the noncontact and contact phases, respectively. By applying a 120V driving voltage, the jaw can provide 70 μm x-axis and 18 μm y-axis displacements with the force of 190 μN. By this design, the real-time position and grasping force information can be obtained in the dual sensing mode. Both analytical calculation and finite-element analysis (FEA were performed to verify the performance of the proposed design. A scaled-up prototype is designed, fabricated and tested through the experiment to verify the structure design of the microgripper.

  5. CMB Maximum Temperature Asymmetry Axis: Alignment with Other Cosmic Asymmetries

    CERN Document Server

    Mariano, Antonio

    2012-01-01

    We use a global pixel based estimator to identify the axis of the residual Maximum Temperature Asymmetry (MTA) (after the dipole subtraction) of the WMAP 7 year Internal Linear Combination (ILC) CMB temperature sky map. The estimator is based on considering the temperature differences between opposite pixels in the sky at various angular resolutions (4 degrees-15 degrees and selecting the axis that maximizes this difference. We consider three large scale Healpix resolutions (N_{side}=16 (3.7 degrees), N_{side}=8 (7.3 degrees) and N_{side}=4 (14.7 degrees)). We compare the direction and magnitude of this asymmetry with three other cosmic asymmetry axes (\\alpha dipole, Dark Energy Dipole and Dark Flow) and find that the four asymmetry axes are abnormally close to each other. We compare the observed MTA axis with the corresponding MTA axes of 10^4 Gaussian isotropic simulated ILC maps (based on LCDM). The fraction of simulated ILC maps that reproduces the observed magnitude of the MTA asymmetry and alignment wit...

  6. Vasoactive intestinal peptide signaling axis in human leukemia

    Institute of Scientific and Technical Information of China (English)

    Glenn; Paul; Dorsam; Keith; Benton; Jarrett; Failing; Sandeep; Batra

    2011-01-01

    The vasoactive intestinal peptide (VIP) signaling axis constitutes a master "communication coordinator" between cells of the nervous and immune systems.To date,VIP and its two main receptors expressed in T lymphocytes,vasoactive intestinal peptide receptor (VPAC)1 and VPAC2,mediate critical cellular functions regulating adaptive immunity,including arresting CD4 T cells in G 1 of the cell cycle,protection from apoptosis and a potent chemotactic recruiter of T cells to the mucosa associated lymphoid compartment of the gastrointestinal tissues.Since the discovery of VIP in 1970,followed by the cloning of VPAC1 and VPAC2 in the early 1990s,this signaling axis has been associated with common human cancers,including leukemia.This review highlights the present day knowledge of the VIP ligand and its receptor expression profile in T cell leukemia and cell lines.Also,there will be a discussion describing how the anti-leukemic DNA binding transcription factor,Ikaros,regulates VIP receptor expression in primary human CD4 T lymphocytes and T cell lymphoblastic cell lines (e.g.Hut-78).Lastly,future goals will be mentioned that are expected to uncover the role of how the VIP signaling axis contributes to human leukemogenesis,and to establish whether the VIP receptor signature expressed by leukemic blasts can provide therapeutic and/or diagnostic information.

  7. MARRT: Medial Axis biased rapidly-exploring random trees

    KAUST Repository

    Denny, Jory

    2014-05-01

    © 2014 IEEE. Motion planning is a difficult and widely studied problem in robotics. Current research aims not only to find feasible paths, but to ensure paths have certain properties, e.g., shortest or safest paths. This is difficult for current state-of-the-art sampling-based techniques as they typically focus on simply finding any path. Despite this difficulty, sampling-based techniques have shown great success in planning for a wide range of applications. Among such planners, Rapidly-Exploring Random Trees (RRTs) search the planning space by biasing exploration toward unexplored regions. This paper introduces a novel RRT variant, Medial Axis RRT (MARRT), which biases tree exploration to the medial axis of free space by pushing all configurations from expansion steps towards the medial axis. We prove that this biasing increases the tree\\'s clearance from obstacles. Improving obstacle clearance is useful where path safety is important, e.g., path planning for robots performing tasks in close proximity to the elderly. Finally, we experimentally analyze MARRT, emphasizing its ability to effectively map difficult passages while increasing obstacle clearance, and compare it to contemporary RRT techniques.

  8. A sensitive method of determining optic axis azimuth based on laser feedback

    International Nuclear Information System (INIS)

    A sensitive method to determine the optic axis azimuth of the birefringence element is presented, which is based on laser feedback. The phase difference between the two intensities in birefringence feedback changes with the angle between the optic axis of the birefringence element and laser original polarization. The phase difference is highly sensitive to the relative position of the optic axis and the laser original polarization. This method is used to highly precisely determine the optic axis azimuth, and is able to distinguish between the fast axis and the slow axis of the birefringence element. Theoretical analysis and experimental results are both demonstrated. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  9. Drop Axis Ratio Distributions in Stratiform and Convective Rain

    Science.gov (United States)

    Thurai, M.; Bringi, V. N.; Petersen, W. A.; Schultz, C.

    2010-01-01

    A fully calibrated low profile 2D video disdrometer (2DVD) has been recording many different rainfall events in Northern Alabama (USA) since June 2007. An earlier publication reported drop shapes and axis ratio distributions determined for some of the events. For one of the cases examined, a noticeable shift in the 3.5 - 3.75 mm drop axis ratio distribution was noted. In this paper, we extend the earlier work by separating the 2DVD measurements into stratiform and convective rain. The separation is made possible by using the minute-by-minute drop size distribution (DSD) measured by the 2DVD. The 1-minute DSDs are fitted to a gamma distribution, and using a simple indexing technique which involves two of the fitted parameters, periods of convective and stratiform rain are separated for a given event. The output of the DSD indexing technique is qualitatively confirmed by comparing with simultaneous time series observations from a co-located UHF profiler which continuously records height profiles of reflectivity, Doppler mean and spectral width, all of which enable the identification of bright-band periods and, furthermore, periods of moderate and deep convection. Excellent consistency is found between the output of the DSD-based separation method and the profiler observations. Next, we utilize the output of DSD index-based separation method to flag the periods of severe convection for a given event. Drop axis ratios during the flagged periods are derived and compared with those during stratiform rain periods. Five cases have been considered. Axis ratio distributions do not show appreciable differences between stratiform and convective periods for four of the cases. The fifth case (the same case as reported earlier) shows a shift in the 3.5 - 3.75 mm drop axis ratios during a prolonged period of convection. The contoured shapes for these drops determined from the 2DVD camera data indicate the possibility of non-axisymmetric oscillations, compared with the contoured

  10. FAMILY HISTORY STUDY OF THE FAMILIAL COAGGREGATION OF BORDERLINE PERSONALITY DISORDER WITH AXIS I AND NON-BORDERLINE DRAMATIC CLUSTER AXIS II DISORDERS

    OpenAIRE

    Zanarini, Mary C.; Barison, Leah K.; Frankenburg, Frances R.; Reich, D. Bradford; Hudson, James I

    2009-01-01

    The purpose of this study was to assess the familial coaggregation of borderline personality disorder (BPD) with a full array of axis I disorders and four axis II disorders (antisocial personality disorder, histrionic personality disorder, narcissistic personality disorder, and sadistic personality disorder) in the first-degree relatives of borderline probands and axis II comparison subjects. Four hundred and forty-five inpatients were interviewed about familial psychopathology using the Revi...

  11. Modal Parameter Identification of New Design of Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Chougule, Prasad; Nielsen, Søren R.K.

    2013-01-01

    Vertical axis wind turbines have lower power efficiency than the horizontal axis wind turbines. However vertical axis wind turbines are proven to be economical and noise free on smaller scale. A new design of three bladed vertical axis wind turbine by using two airfoils in construction of each bl...... Abaqus cae software. The study is limited to evaluate lowest fundamental modal frequencies and mode shapes of proposed wind turbine....

  12. Mechanical Coupling between Endoderm Invagination and Axis Extension in Drosophila.

    Directory of Open Access Journals (Sweden)

    Claire M Lye

    Full Text Available How genetic programs generate cell-intrinsic forces to shape embryos is actively studied, but less so how tissue-scale physical forces impact morphogenesis. Here we address the role of the latter during axis extension, using Drosophila germband extension (GBE as a model. We found previously that cells elongate in the anteroposterior (AP axis in the extending germband, suggesting that an extrinsic tensile force contributed to body axis extension. Here we further characterized the AP cell elongation patterns during GBE, by tracking cells and quantifying their apical cell deformation over time. AP cell elongation forms a gradient culminating at the posterior of the embryo, consistent with an AP-oriented tensile force propagating from there. To identify the morphogenetic movements that could be the source of this extrinsic force, we mapped gastrulation movements temporally using light sheet microscopy to image whole Drosophila embryos. We found that both mesoderm and endoderm invaginations are synchronous with the onset of GBE. The AP cell elongation gradient remains when mesoderm invagination is blocked but is abolished in the absence of endoderm invagination. This suggested that endoderm invagination is the source of the tensile force. We next looked for evidence of this force in a simplified system without polarized cell intercalation, in acellular embryos. Using Particle Image Velocimetry, we identify posteriorwards Myosin II flows towards the presumptive posterior endoderm, which still undergoes apical constriction in acellular embryos as in wildtype. We probed this posterior region using laser ablation and showed that tension is increased in the AP orientation, compared to dorsoventral orientation or to either orientations more anteriorly in the embryo. We propose that apical constriction leading to endoderm invagination is the source of the extrinsic force contributing to germband extension. This highlights the importance of physical

  13. Automated segmentation of the human hippocampus along its longitudinal axis.

    Science.gov (United States)

    Lerma-Usabiaga, Garikoitz; Iglesias, Juan Eugenio; Insausti, Ricardo; Greve, Douglas N; Paz-Alonso, Pedro M

    2016-09-01

    The human hippocampal formation is a crucial brain structure for memory and cognitive function that is closely related to other subcortical and cortical brain regions. Recent neuroimaging studies have revealed differences along the hippocampal longitudinal axis in terms of structure, connectivity, and function, stressing the importance of improving the reliability of the available segmentation methods that are typically used to divide the hippocampus into its anterior and posterior parts. However, current segmentation conventions present two main sources of variability related to manual operations intended to correct in-scanner head position across subjects and the selection of dividing planes along the longitudinal axis. Here, our aim was twofold: (1) to characterize inter- and intra-rater variability associated with these manual operations and compare manual (landmark based) and automatic (percentage based) hippocampal anterior-posterior segmentation procedures; and (2) to propose and test automated rotation methods based on approximating the hippocampal longitudinal axis to a straight line (estimated with principal component analysis, PCA) or a quadratic Bézier curve (fitted with numerical methods); as well as an automated anterior-posterior hippocampal segmentation procedure based on the percentage-based method. Our results reveal that automated rotation and segmentation procedures, used in combination or independently, minimize inconsistencies generated by the accumulation of manual operations while providing higher statistical power to detect well-known effects. A Matlab-based implementation of these procedures is made publicly available to the research community. Hum Brain Mapp 37:3353-3367, 2016. © 2016 Wiley Periodicals, Inc. PMID:27159325

  14. HPA axis dysregulation in men with hypersexual disorder.

    Science.gov (United States)

    Chatzittofis, Andreas; Arver, Stefan; Öberg, Katarina; Hallberg, Jonas; Nordström, Peter; Jokinen, Jussi

    2016-01-01

    Hypersexual disorder integrating pathophysiological aspects such as sexual desire deregulation, sexual addiction, impulsivity and compulsivity was suggested as a diagnosis for the DSM-5. However, little is known about the neurobiology behind this disorder. A dysregulation of the hypothalamic pituitary adrenal (HPA) axis has been shown in psychiatric disorders but has not been investigated in hypersexual disorder. The aim of this study was to investigate the function of the HPA axis in hypersexual disorder. The study includes 67 male patients with hypersexual disorder and 39 healthy male volunteers. Basal morning plasma levels of cortisol and ACTH were assessed and low dose (0.5mg) dexamethasone suppression test was performed with cortisol and ACTH measured post dexamethasone administration. Non-suppression status was defined with DST-cortisol levels ≥ 138 nmol/l. The Sexual Compulsive scale (SCS), Hypersexual disorder current assessment scale (HD:CAS), Montgomery-Åsberg Depression Scale-self rating (MADRS-S) and Childhood trauma questionnaire (CTQ), were used for assessing hypersexual behavior, depression severity and early life adversity. Patients with hypersexual disorder were significantly more often DST non-suppressors and had significantly higher DST-ACTH levels compared to healthy volunteers. The patients reported significantly more childhood trauma and depression symptoms compared to healthy volunteers. CTQ scores showed a significant negative correlation with DST-ACTH whereas SCS and HD:CAS scores showed a negative correlation with baseline cortisol in patients. The diagnosis of hypersexual disorder was significantly associated DST non-suppression and higher plasma DST-ACTH even when adjusted for childhood trauma. The results suggest HPA axis dysregulation in male patients with hypersexual disorder.

  15. Research on identifying the dynamic error model of strapdown gyro on 3-axis turntable

    Institute of Scientific and Technical Information of China (English)

    WANG Hai; REN Shun-qing; WANG Chang-hong

    2005-01-01

    The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system.In order to identify the dynamic error model coefficients accurately, the static erTor model coefficients which lay a foundation for compensating while identifying the dynamic error model are identified in the gravity acceleration fields by using angular position function of the three-axis turntable. The angular acceleration and angular velocity are excited on the input, output and spin axis of the gyros when the outer axis and the middle axis of a threeaxis turntable are in the uniform angular velocity state simultaneously, while the inner axis of the turntable is in different static angular positions. 8 groups of data are sampled when the inner axis is in 8 different angular positions. These data are the function of the middle axis positions and the inner axis positions. For these data, harmonic analysis method is applied two times versus the middle axis positions and inner axis positions respectively so that the dynamic error model coefficients are finally identified through the least square method. In the meantime the optimal angular velocity of the outer axis and the middle axis are selected by computing the determination value of the information matrix.

  16. Adolescent Survivors of Hurricane Katrina: A Pilot Study of Hypothalamic-Pituitary-Adrenal Axis Functioning

    Science.gov (United States)

    Pfefferbaum, Betty; Tucker, Phebe; Nitiéma, Pascal

    2015-01-01

    Background: The hypothalamic-pituitary-adrenal (HPA) axis constitutes an important biological component of the stress response commonly studied through the measurement of cortisol. Limited research has examined HPA axis dysregulation in youth exposed to disasters. Objective: This study examined HPA axis activation in adolescent Hurricane Katrina…

  17. Hypothalamic-pituitary-adrenal axis activity in older persons with and without a depressive disorder

    NARCIS (Netherlands)

    Rhebergen, D.; Korten, N. C. M.; Penninx, B. W. J. H.; Stek, M. L.; van der Mast, R. C.; Voshaar, R. Oude; Comijs, H. C.

    2015-01-01

    Background: Altered functioning of the hypothalamic-pituitary-adrenal axis (HPA-axis) has been associated with depression, but findings have been inconsistent. Among older depressed persons, both hyperactivity and hypo-activity of the HPA-axis were demonstrated. However, most studies were population

  18. The orientation of the solar rotation axis from Doppler velocity observations

    Science.gov (United States)

    Labonte, B. J.

    1981-01-01

    Mt. Wilson observations of solar velocity fields have been examined for evidence that the rotation axis of the nonmagnetic gas at the solar surface is oriented differently that the axis found by Carrington (1863) from sunspot observations. No difference is found with accuracy of 0.15 in the angle of inclination of the axis to the ecliptic.

  19. Role of the lysophosphatidylinositol/GPR55 axis in cancer.

    Science.gov (United States)

    Falasca, Marco; Ferro, Riccardo

    2016-01-01

    Lysophosphatidylinositol (LPI) is a well-known bioactive lipid that is able to activate signalling cascades relevant to cell proliferation, migration, survival and tumourigenesis. It is well-established that the G protein-coupled receptor 55 (GPR55) is the specific receptor for LPI. Several investigations have demonstrated that the signalling pathways activated by LPI through its receptor GPR55 play a pivotal role in different cancer type. This review focuses on the role of the LPI/GPR55 axis, in particular with regards to its pharmacological potential therapeutic exploitation. PMID:26588872

  20. Tilted axis cranking covariant density functional theory and its applications

    International Nuclear Information System (INIS)

    Recent progress on tilted axis cranking covariant density functional theory (CDFT) and its applications to nuclear magnetic and antimagnetic rotation are briefly presented. In particular, the magnetic rotation band in 198Pb and the antimagnetic rotational band in 105Cd are discussed. Without any additional parameter, the experimental relation between angular momentum and rotational frequency for the magnetic rotation band in 198Pb as well as the data of B(E2) values for the antimagnetic rotation band in 105Cd are reproduced very well

  1. Defining normalcy of the somatotropic axis: an attainable goal?

    Science.gov (United States)

    Barkan, Ariel L

    2007-01-01

    The diagnoses of acromegaly and dwarfism require biochemical confirmation of abnormal GH and IGF-1 concentrations. The same parameters are used for therapeutic decisions, i.e. initiation or termination of particular treatments. Therefore, reliable and epidemiologically and statistically proven criteria of normalcy for GH and IGF-1 are required for these tasks to be accomplished. Despite major progress in all these areas, the definition of what constitutes "normalcy" of the somatotropic axis is still lacking. Using an example of acromegaly, we discuss the contradictions and the uncertainties of the biochemical diagnosis of this disease. PMID:17410470

  2. Impedances and power losses for an off-axis beam

    CERN Document Server

    Kurennoy, S S

    1996-01-01

    A method for calculating coupling impedances and power losses for off-axis beams is developed. It is applied to calculate impedances of small localized discontinuities like holes and slots, as well as the impedance due to a finite resistivity of chamber walls, in homogeneous chambers with an arbitrary shape of the chamber cross section. The approach requires to solve a two-dimensional electrostatic problem, which can be easily done numerically in the general case, while for some particular cases analytical solutions are obtained.

  3. Error Model and Accuracy Calibration of 5-Axis Machine Tool

    Directory of Open Access Journals (Sweden)

    Fangyu Pan

    2013-08-01

    Full Text Available To improve the machining precision and reduce the geometric errors for 5-axis machinetool, error model and calibration are presented in this paper. Error model is realized by the theory of multi-body system and characteristic matrixes, which can establish the relationship between the cutting tool and the workpiece in theory. The accuracy calibration was difficult to achieve, but by a laser approach-laser interferometer and laser tracker, the errors can be displayed accurately which is benefit for later compensation.

  4. Multi-axis analog adaptive feedforward cancellation of cryocooler vibration

    Science.gov (United States)

    Collins, Simon Andrew

    1994-01-01

    The vibration produced by Stirling cryocoolers is incompatible with spacecraft-borne precision-pointing imaging instruments. Thermal considerations prevent the addition of sufficient mechanical isolation to eliminate the effects of this vibration. The objective of this research is the design, analysis, and experimental verification of a multi-axis vibration cancellation system for the expander of a split Stirling cryocooler. Cancellation of the periodic cryocooler vibration is achieved with a set of load cells, a custom three-axis electrodynamic actuator, and a narrowband adaptive feedforward controller. In order to size the actuator, a simple model of the cryocooler's vibration is combined with a first-order analysis of a four-magnet two-return-plate forcing element. While the resulting actuator has sufficient force capability, it exhibits significant nonlinearity. A nonlinear actuator model is developed that accounts for in-plane flexure restraint due to both large-amplitude static deflections and large-amplitude vibrations. Numerical solutions of the nonlinear model accurately reflect jump phenomena and higher harmonics observed in the actuator's response. The adaptive feedforward controller employs the filtered-x least-mean-square (FXLMS) algorithm to update an adaptive filter. Rather than implementing this filter with a digital signal processor (DSP), for which there is little flight heritage, a continuous-time analog realization of the FXLMS filter is selected. Theoretically, the FXLMS filter may be represented by an equivalent linear transfer function. However a comprehensive treatment of factors associated with the actual implementation reveals the limitations of the transfer function representation. Factors such as harmonic distortion of the reference signal and imperfect quadrature are shown to result in frequency-shifted terms in the filter's output. The presence of these output components is confirmed experimentally, and their effect on performance is

  5. The diet-microbiota-metabolite axis regulates the host physiology.

    Science.gov (United States)

    Yamada, Takahiro; Takahashi, Daisuke; Hase, Koji

    2016-07-01

    The intestinal microbiota has been implicated in a wide range of diseases, including inflammatory bowel disease, obesity and cancer. Food ingredients are considered a major determinant of gut microbial composition, as exemplified by high-fat diet-induced dysbiosis that can affect host physiology. Accumulating studies show that microbial metabolites are key regulators of the intestinal epithelial barrier and gut immunity. In particular, short-chain fatty acids produced by bacterial fermentation of indigestible polysaccharides have profound impacts on host physiology beyond the gut. In this review, we describe the influences of the diet-microbiota-metabolite axis on host physiology, and especially on the immune and metabolic systems. PMID:26970281

  6. On the off-axis tensile test for unidirectional composites

    Science.gov (United States)

    Nemeth, M. P.; Herakovich, C. T.; Post, D.

    1982-01-01

    The off axis tensile test was examined experimentally to obtain actual displacement fields over the surface of graphite polyimide coupon specimens. The experimental results were compared with approximate analytical solutions and generated finite element results. An optical method of high sensitivity moire interferometry was used to determine the actual displacements to high precision. The approximate analytical solution and the finite element results compare very favorably with the measured centerline displacements in the test section, and the finite element displacement fields provide excellent agreement with the moire displacements throughout the specimen. A 15 degree fiber orientation and coupon aspect ratios of 5 and 15 are presented.

  7. A Preliminary Shape and Spin Axis Model for 595 Polyxena

    Science.gov (United States)

    Warner, Brian D.

    2008-10-01

    Photometric observations made at the Palmer Divide Observatory during the 2006 and 2008 apparitions of the main-belt asteroid 595 Polyxena were combined with dense lightcurves from 1993 included in the Uppsala Asteroid Photometric Catalog and a sparse lightcurve based on data from the USNO to determine a preliminary shape and spin axis model. Two solutions dominated the result set, one prograde (? = 42°, ß = 8°) and one retrograde (? = 222°, ß = -4°). The uncertainty in each coordinate is ± 5°. The sidereal period was found to be 11.794162 ± 0.000023 h.

  8. Asteroid Shape and Spin Axis Modeling Via Light Curve Inversion

    Science.gov (United States)

    Friz, Paul; Gokhale, V.

    2013-01-01

    We present light curves and shape and spin axis models for the five asteroids: 291 Alice, 281 Lucretia, 321 Florentina, 714 Ulula, and 3169 Ostro. These models were obtained using data taken from the Truman Observatory, the Asteroid Photometric Catalogue, and the Minor Planet Center. Knowledge of individual asteroids shapes and spin axes is vital to understanding the solar system. However, currently only 213 out of the 500,000 asteroids with known orbits have been modeled. By taking many light curves of asteroids over several apparitions it is possible to determine their shapes and spin axes by a process known as light curve inversion.

  9. Wake-Assisted Windmill System with Parallel Vertical-Axis

    OpenAIRE

    YAMAGISHI, Masaki; Sato, Daisuke; MIYASHITA, Jun; Nozaki, Kentaro; 山岸, 真幸; 佐藤, 大資; 宮下, 准; 野崎, 健太郎

    2003-01-01

    For the improvement of the performance of drag-type windmills with vertical-axis, the experimental study proposed the windmill system using the wake behind a bluff body. The model windmill has two Savonius rotors that were set in parallel behind the circular cylinder. Through the wind tunnel experiment the revolution of the rotor of the windmill system was compared with that of the single rotor. The revolution of the windmill system was found higher than that of the single rotor. Also the opt...

  10. The interleukin-20 receptor axis in early rheumatoid arthritis

    DEFF Research Database (Denmark)

    Kragstrup, Tue Wenzel; Greisen, Stinne Ravn; Nielsen, Morten Aagaard;

    2016-01-01

    BACKGROUND: Rheumatoid arthritis (RA) is often characterized by the presence of rheumatoid factor, anti-citrullinated protein antibodies, and bone erosions. Current therapies can compromise immunity, leading to risk of infection. The interleukin-20 receptor (IL-20R) axis comprising IL-19, IL-20...... RA synovial fluid compared with monocytes from both RA and healthy control peripheral blood. The plasma concentrations of IL-20 and IL-24 were increased in rheumatoid factor and anti-citrullinated protein antibody positive compared with negative early RA patients (all P < 0.0001). Immune complexes...

  11. Experimental characterization of vertical-axis wind turbine noise.

    Science.gov (United States)

    Pearson, C E; Graham, W R

    2015-01-01

    Vertical-axis wind turbines are wind-energy generators suitable for use in urban environments. Their associated noise thus needs to be characterized and understood. As a first step, this work investigates the relative importance of harmonic and broadband contributions via model-scale wind-tunnel experiments. Cross-spectra from a pair of flush-mounted wall microphones exhibit both components, but further analysis shows that the broadband dominates at frequencies corresponding to the audible range in full-scale operation. This observation has detrimental implications for noise-prediction reliability and hence also for acoustic design optimization. PMID:25618090

  12. Resonance acceptor states in single-axis deformed semiconductors

    CERN Document Server

    Odnoblyudov, M A; Yassievich, I N

    2002-01-01

    The new approach is proposed to the resonance state parameters, making it possible to determine also the probabilities of the resonance scattering and capture probability into the resonance state. It is based on the application of the Fano configuration interaction method. Two different Hamiltonians of the zero approximation are applied for the continuum states and local priming state. The wave functions are plotted by the method, accepted in the common scattering theory. The detailed consideration and concrete calculations for the acceptor resonance states in the single-axis deformed germanium by the pressure along the axes [001] and [111] are carried out

  13. Resonances and Aerodynamic Damping of a Vertical Axis Wind Turbine

    OpenAIRE

    Ottermo, Fredric; Bernhoff, Hans

    2012-01-01

    The dynamics of a straight-bladed vertical axis wind turbine is investigated with respect to oscillations due to the elasticity of struts and shaft connecting to the hub. In particular, for the three-bladed turbine, a concept is proposed for dimensioning the turbine to maximize the size of the resonance free rpm range for operation. The effect of aerodynamic damping on the struts is also considered. The damping of these types of oscillations for a typical turbine is found to be good.

  14. Stable three-axis nuclear-spin gyroscope in diamond

    Science.gov (United States)

    Ajoy, Ashok; Cappellaro, Paola

    2012-12-01

    Gyroscopes find wide applications in everyday life from navigation and inertial sensing to rotation sensors in hand-held devices and automobiles. Current devices, based on either atomic or solid-state systems, impose a choice between long-time stability and high sensitivity in a miniaturized system. Here, we introduce a quantum sensor that overcomes these limitations by providing a sensitive and stable three-axis gyroscope in the solid state. We achieve high sensitivity by exploiting the long coherence time of the 14N nuclear spin associated with the nitrogen-vacancy center in diamond, combined with the efficient polarization and measurement of its electronic spin. Although the gyroscope is based on a simple Ramsey interferometry scheme, we use coherent control of the quantum sensor to improve its coherence time and robustness against long-time drifts. Such a sensor can achieve a sensitivity of η˜0.5(mdegs-1)/Hzmm3 while offering enhanced stability in a small footprint. In addition, we exploit the four axes of delocalization of the nitrogen-vacancy center to measure not only the rate of rotation, but also its direction, thus obtaining a compact three-axis gyroscope.

  15. Searching for Cosmological Preferred Axis using cosmographic approach

    CERN Document Server

    Salehi, Amin

    2016-01-01

    Recent released Planck data and other astronomical observations show that the universe may be anisotropic on large scales. This hints a cosmological privileged axis in our anisotropic expanding universe. This paper proceeds a modified redshift in anisotropic cosmological model as $ 1+\\tilde{z}(t,\\hat{\\textbf{p}})=\\frac{a(t_{0)}}{a(t)}(1-A(\\hat{\\textbf{n}}.\\hat{\\textbf{p}}))$ (where $A$ is the magnitude of anisotropy ,$\\hat{\\textbf{n}}$ is the direction of privileged axis, and $\\hat{\\textbf{p}}$ is the direction of each SNe Ia sample to galactic coordinates) along with anisotropic parameter $\\delta=\\frac{A(\\hat{\\textbf{n}}.\\hat{\\textbf{p}})}{1+A(\\hat{\\textbf{n}}.\\hat{\\textbf{p}})}$. The luminosity distance is expanded with model-independent cosmographic parameters as a function of modified redshift $\\tilde{z}$. As the transformation matrix $M(n\\times n)$ is obtained to convert the Taylor series coefficients of isotropic luminosity distance to corresponding anisotropic parameters. These results culminate the ma...

  16. Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics

    CERN Document Server

    Jeff, A; Welsch, CP

    2013-01-01

    The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 1015 electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMA...

  17. Related Axis: The Extension to XPath Towards Effective XML Search

    Institute of Scientific and Technical Information of China (English)

    Jun-Feng Zhou; Tok Wang Ling; Zhi-Feng Bao; Xiao-Feng Meng

    2012-01-01

    We investigate the limitations of existing XML search methods and propose a new semantics,related relationship,to effectively capture meaningful relationships of data elements from XML data in the absence of structural constraints.Then we make an extension to XPath by introducing a new axis,related axis,to specify the related relationship between query nodes so as to enhance the flexibility of XPath.We propose to reduce the cost of computing the related relationship by a new schema summary that summarizes the related relationship from the original schema without any loss.Based on this schema summary,we introduce two indices to improve the performance of query processing.Our algorithm shows that the evaluation of most queries can be equivalently transformed into just a few selection and value join operations,thus avoids the costly structural join operations.The experimental results show that our method is effective and efficient in terms of comparing the effectiveness of the related relationship with existing keyword search semantics and comparing the efficiency of our evaluation methods with existing query engines.

  18. Application of Circulation Controlled Blades for Vertical Axis Wind Turbines

    Directory of Open Access Journals (Sweden)

    Velissarios Kourkoulis

    2013-07-01

    Full Text Available The blades of a vertical axis wind turbine (VAWT rotor see an inconsistent angle of attack through its rotation. Consequently, VAWT blades generally use symmetrical aerofoils with a lower lift-to-drag ratio than cambered aerofoils tailored to maximise horizontal axis wind turbine rotor performance. This paper considers the feasibility of circulation controlled (CC VAWT blades, using a tangential air jet to provide lift and therefore power augmentation. However CC blade sections require a higher trailing-edge thickness than conventional sections giving rise to additional base drag. The choice of design parameters is a compromise between lift augmentation, additional base drag as well as the power required to pump the air jet. Although CC technology has been investigated for many years, particularly for aerospace applications, few researchers have considered VAWT applications. This paper considers the feasibility of the technology, using Computational Fluid Dynamics to evaluate a baseline CC aerofoil with different trailing-edge ellipse shapes. Lift and drag increments due to CC are considered within a momentum based turbine model to determine net power production. The study found that for modest momentum coefficients significant net power augmentation can be achieved with a relatively simple aerofoil geometry if blowing is controlled through the blades rotation.

  19. Rotation axis demultiplexer enabling simultaneous computed tomography of multiple samples.

    Science.gov (United States)

    Trtik, Pavel; Geiger, Fabian; Hovind, Jan; Lang, Udo; Lehmann, Eberhard; Vontobel, Peter; Peetermans, Steven

    2016-01-01

    This paper describes a device that allows for simultaneous tomographic imaging of samples on three independent rotational axes. This rotation axis demultiplexer (POLYTOM) is equipped with anti-backlash gears and placed on a standard sample rotation stage thus allowing for the transformation of the input rotation axis onto two additional parallel vertical axes. Consequently, three times the number of samples can be investigated within a given time period, thereby reducing the acquisition time of multiple sample tomographic investigations by a factor of three. The results of our pilot experiments using neutron tomographic imaging are presented. We foresee that the device will be of particular use for tomographic imaging of elongated samples at low-flux (e.g. neutron) sources; however, its use for the more widespread types of imaging techniques (e.g. X-rays) is not ruled out. The highlights of this new device for the purpose of the (neutron) computed tomography are: •Anti-backlash transformation of the input rotation onto two additional rotational axes.•Reduction of the acquisition time of the multiple sample tomographic investigations by a factor of three.•Low-cost. PMID:27158597

  20. Computational analysis of vertical axis wind turbine arrays

    Science.gov (United States)

    Bremseth, J.; Duraisamy, K.

    2016-10-01

    Canonical problems involving single, pairs, and arrays of vertical axis wind turbines (VAWTs) are investigated numerically with the objective of understanding the underlying flow structures and their implications on energy production. Experimental studies by Dabiri (J Renew Sustain Energy 3, 2011) suggest that VAWTs demand less stringent spacing requirements than their horizontal axis counterparts and additional benefits may be obtained by optimizing the placement and rotational direction of VAWTs. The flowfield of pairs of co-/counter-rotating VAWTs shows some similarities with pairs of cylinders in terms of wake structure and vortex shedding. When multiple VAWTs are placed in a column, the extent of the wake is seen to spread further downstream, irrespective of the direction of rotation of individual turbines. However, the aerodynamic interference between turbines gives rise to regions of excess momentum between the turbines which lead to significant power augmentations. Studies of VAWTs arranged in multiple columns show that the downstream columns can actually be more efficient than the leading column, a proposition that could lead to radical improvements in wind farm productivity.

  1. Manufacturing of injection moulding tool with five axis milling machine

    Directory of Open Access Journals (Sweden)

    I. Micetic

    2013-05-01

    Full Text Available Purpose: The main intention of this paper is to show the advanced technology for production of the electrode for EDM that has a relatively complex geometry. Five axes CNC machining centre is used for production of an example ice scrapers since application of other type of machine requires a lot of auxiliary time and resources.Design/methodology/approach: Advanced manufacturing technology involves the application of various software tools and technologies, among them the tools and technology to automate the design, analysis, testing and manufacturing occupy a key position.Findings: The main outcomes are decrease of production time, better quality of surface and product geometry. Decrease of cutting time refers to decrease of number of used tools, preparation time is lower in comparison with conventional machines.Research limitations/implications: The practical part included the design of electrode in the CAD system, SolidWorks 2010, production of NC program for the operating unit Haidenhain iTNC 530 in CAM system ESPRIT 2010, and finally making the electrode on five axis machine center DMG DMU 40 Monoblock. Originality/value: Presented technology for a five-axis machining centre, ensures a great advantages in the process preparation while reduced set-up time, reduced number of required accessories and devices, reduced number of special tools is needed. This knowledge can support the development and design of technological processes.

  2. Shock margin testing of a one-axis MEMS accelerometer.

    Energy Technology Data Exchange (ETDEWEB)

    Parson, Ted Blair; Tanner, Danelle Mary; Buchheit, Thomas Edward

    2008-07-01

    Shock testing was performed on a selected commercial-off-the-shelf - MicroElectroMechanical System (COTS-MEMS) accelerometer to determine the margin between the published absolute maximum rating for shock and the 'measured' level where failures are observed. The purpose of this testing is to provide baseline data for isolating failure mechanisms under shock and environmental loading in a representative device used or under consideration for use within systems and assemblies of the DOD/DOE weapons complex. The specific device chosen for this study was the AD22280 model of the ADXL78 MEMS Accelerometer manufactured by Analog Devices Inc. This study focuses only on the shock loading response of the device and provides the necessary data for adding influence of environmental exposure to the reliability of this class of devices. The published absolute maximum rating for acceleration in any axis was 4000 G for this device powered or unpowered. Results from this study showed first failures at 8000 G indicating a margin of error of two. Higher shock level testing indicated that an in-plane, but off-axis acceleration was more damaging than one in the sense direction.

  3. Computational analysis of vertical axis wind turbine arrays

    Science.gov (United States)

    Bremseth, J.; Duraisamy, K.

    2016-03-01

    Canonical problems involving single, pairs, and arrays of vertical axis wind turbines (VAWTs) are investigated numerically with the objective of understanding the underlying flow structures and their implications on energy production. Experimental studies by Dabiri (J Renew Sustain Energy 3, 2011) suggest that VAWTs demand less stringent spacing requirements than their horizontal axis counterparts and additional benefits may be obtained by optimizing the placement and rotational direction of VAWTs. The flowfield of pairs of co-/counter-rotating VAWTs shows some similarities with pairs of cylinders in terms of wake structure and vortex shedding. When multiple VAWTs are placed in a column, the extent of the wake is seen to spread further downstream, irrespective of the direction of rotation of individual turbines. However, the aerodynamic interference between turbines gives rise to regions of excess momentum between the turbines which lead to significant power augmentations. Studies of VAWTs arranged in multiple columns show that the downstream columns can actually be more efficient than the leading column, a proposition that could lead to radical improvements in wind farm productivity.

  4. On the spin-axis dynamics of a Moonless Earth

    International Nuclear Information System (INIS)

    The variation of a planet's obliquity is influenced by the existence of satellites with a high mass ratio. For instance, Earth's obliquity is stabilized by the Moon and would undergo chaotic variations in the Moon's absence. In turn, such variations can lead to large-scale changes in the atmospheric circulation, rendering spin-axis dynamics a central issue for understanding climate. The relevant quantity for dynamically forced climate change is the rate of chaotic diffusion. Accordingly, here we re-examine the spin-axis evolution of a Moonless Earth within the context of a simplified perturbative framework. We present analytical estimates of the characteristic Lyapunov coefficient as well as the chaotic diffusion rate and demonstrate that even in absence of the Moon, the stochastic change in Earth's obliquity is sufficiently slow to not preclude long-term habitability. Our calculations are consistent with published numerical experiments and illustrate the putative system's underlying dynamical structure in a simple and intuitive manner.

  5. Miniature image guided three-axis scanning and positioning system

    Science.gov (United States)

    Avirovik, Dragan; Dave, Digant; Priya, Shashank

    2012-04-01

    We have developed a high precision three axes scanning and positioning system for integration with Multifunctional Image Guided Surgical (MIGS) Platform. The stage integrates three main components: an optical coherence tomography (OCT) probe, laser scalpel and suction cup. The requirements for this stage were to provide scanning area of 400mm2, resolution of less than 10 microns and scanning velocity in the range of 10 - 40 mm/s. The stage was modeled using computer aided design software NX Unigraphics. In addition to the parameters mentioned above, additional boundary conditions for the stage were set as low volume and modularity. Optimized stage model was fabricated by using rapid prototyping technique that integrates low cost stepper motors, threaded rod drive train and a stepper motor controller. The EZ4axis stepper motor controller was able to provide 1/8th microstep resolution control over the motors, which met the criterion desired for the MIGS platform. Integration of computer controlled three-axis stage with MIGS platform provides the opportunity for conducting intricate surgical procedures using remote control or joystick. The device is image guided using the OCT probe and it is able to pin point any location requiring a laser scalpel incision. Due to the scanning capabilities, a high quality threedimensional image of the tissue topography is obtained which allows the surgeon to make a confident decision of where to apply the laser scalpel and make an incision.

  6. Actuator line modeling of vertical-axis turbines

    CERN Document Server

    Bachant, Peter; Wosnik, Martin

    2016-01-01

    To bridge the gap between high and low fidelity numerical modeling tools for vertical-axis (or cross-flow) turbines (VATs or CFTs), an actuator line model (ALM) was developed and validated for both a high and a medium solidity vertical-axis turbine at rotor diameter Reynolds numbers $Re_D \\sim 10^6$. The ALM is a hybridization of classical blade element theory with Navier--Stokes based flow models, and in this study both $k$--$\\epsilon$ Reynolds-averaged Navier--Stokes (RANS) and Smagorinsky large eddy simulation (LES) turbulence models were tested. The RANS models were able to be run on coarse grids while still providing good convergence behavior in terms of the mean power coefficient, and also approximately four orders of magnitude reduction in computational expense compared with 3-D blade-resolved RANS simulations. Submodels for dynamic stall, end effects, added mass, and flow curvature were implemented, resulting in reasonable performance predictions for the high solidity rotor, more discrepancies for the...

  7. Three-axis positional drift correction in scanning probe microscopy

    Science.gov (United States)

    Follin, Nathan D.; Musalo, Christopher J.; Trawick, Matthew L.

    2011-03-01

    Positional drift in scanning probe microscopy can cause image distortion and metrological errors of tens of nanometers or more. It can arise from thermal drift, due to thermal expansion of materials in the sample and microscope while scanning, or from piezo creep, particularly along the z axis. We present a technique for correcting positional drift errors in all three axes. Our method works by comparing each scanned topographical image to a second, partial scan, taken immediately afterwards, on which the fast and slow scan axes have been reversed. We model the positional distortion as a low-order polynomial function in three dimensions, searching for the set of correctional coefficients that minimizes the difference between the two scans. Using this technique we have successfully reduced positional errors from 50 nm to 0.5 nm in the z axis, and from 40 nm to 2 nm (about half of a single pixel) in the xy plane. Supported by an award from Research Corporation for Science Advancement, and by the American Chemical Society Petroleum Research Fund through Grant number 46380-GB7.

  8. Comparison of aerodynamic models for Vertical Axis Wind Turbines

    DEFF Research Database (Denmark)

    Ferreira, C. Simão; Aagaard Madsen, Helge; Barone, M.;

    2014-01-01

    Multi-megawatt Vertical Axis Wind Turbines (VAWTs) are experiencing an increased interest for floating offshore applications. However, VAWT development is hindered by the lack of fast, accurate and validated simulation models. This work compares six different numerical models for VAWTS: a multipl......, which explicitly model the wake as a system of vorticity, show mostly differences due to the instantaneous or time averaged formulation of the loading and flow, for which further research is needed.......Multi-megawatt Vertical Axis Wind Turbines (VAWTs) are experiencing an increased interest for floating offshore applications. However, VAWT development is hindered by the lack of fast, accurate and validated simulation models. This work compares six different numerical models for VAWTS: a multiple...... solidity and fixed pitch angle, included heavily loaded rotors, in inviscid flow. The results show that the streamtube models are inaccurate, and that correct predictions of rotor power and rotor thrust are an effect of error cancellation which only occurs at specific configurations. The other four models...

  9. Simplified aeroelastic modeling of horizontal axis wind turbines

    Science.gov (United States)

    Wendell, J. H.

    1982-09-01

    Certain aspects of the aeroelastic modeling and behavior of the horizontal axis wind turbine (HAWT) are examined. Two simple three degree of freedom models are described in this report, and tools are developed which allow other simple models to be derived. The first simple model developed is an equivalent hinge model to study the flap-lag-torsion aeroelastic stability of an isolated rotor blade. The model includes nonlinear effects, preconing, and noncoincident elastic axis, center of gravity, and aerodynamic center. A stability study is presented which examines the influence of key parameters on aeroelastic stability. Next, two general tools are developed to study the aeroelastic stability and response of a teetering rotor coupled to a flexible tower. The first of these tools is an aeroelastic model of a two-bladed rotor on a general flexible support. The second general tool is a harmonic balance solution method for the resulting second order system with periodic coefficients. The second simple model developed is a rotor-tower model which serves to demonstrate the general tools. This model includes nacelle yawing, nacelle pitching, and rotor teetering. Transient response time histories are calculated and compared to a similar model in the literature. Agreement between the two is very good, especially considering how few harmonics are used. Finally, a stability study is presented which examines the effects of support stiffness and damping, inflow angle, and preconing.

  10. CFD Simulation of Twin Vertical Axis Tidal Turbines System

    Directory of Open Access Journals (Sweden)

    Syed Shah Khalid

    2013-01-01

    Full Text Available As concerns about rising fossil-fuel prices, energy security and climate-change increase, renewable energy can play a vital role in producing local, clean and inexhaustible energy to supply world rising demand for electricity. In this study, hydrodynamic analysis of vertical axis tidal turbine operating side-by-side is numerically analyzed. Two-dimensional numerical modeling of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX; this is based on a Reynolds-Averaged Navier-Stokes (RANS model. The purpose is to find an optimal distance between the turbines where interaction effect is minimal and constructive, where the turbines operate more efficiently than stand alone turbine. A transient simulation is done on Vertical Axis Tidal Turbine (VATT using the Shear Stress Transport Turbulence (SST model. Main hydrodynamic parameters like torque T, coefficients of performance CP and coefficient of torque CT are investigated. The gap spacing between the turbines has an important role in performance improvement and also in vortex shedding suppression for the flows around two counters rotating systems. The simulation results are validated with Ye and Calisal data. The results of this study prove that the total power output of a twin-turbine system with an optimal layout can be about 24% higher than two times that of a stand-alone turbine. We conclude that the optimally configured counter-rotating twin turbines should be a side-by-side arrangement.

  11. Harnessing Tidal Energy Using Vertical Axis Tidal Turbine

    Directory of Open Access Journals (Sweden)

    Syed Shah Khalid

    2013-01-01

    Full Text Available An overview of the current design practices in the field of Renewable Energy (RE is presented; also paper delineates the background to the development of unique and novel techniques for power generation using the kinetic energy of tidal streams and other marine currents. Also this study focuses only on vertical axis tidal turbine. Tidal stream devices have been developed as an alternative method of extracting the energy from the tides. This form of tidal power technology poses less threat to the environment and does not face the same limiting factors associated with tidal barrage schemes, therefore making it a more feasible method of electricity production. Large companies are taking interest in this new source of power. There is a rush to research and work with this new energy source. Marine scientists are looking into how much these will affect the environment, while engineers are developing turbines that are harmless for the environment. In addition, the progression of technological advancements tracing several decades of R & D efforts on vertical axis turbines is highlighted.

  12. PRIGo: a new multi-axis goniometer for macromolecular crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Waltersperger, Sandro; Olieric, Vincent, E-mail: vincent.olieric@psi.ch; Pradervand, Claude [Paul Scherrer Institute, Villigen PSI (Switzerland); Glettig, Wayne [Centre Suisse d’Electronique et Microtechnique SA, Neuchâtel 2002 (Switzerland); Salathe, Marco; Fuchs, Martin R.; Curtin, Adrian; Wang, Xiaoqiang; Ebner, Simon; Panepucci, Ezequiel; Weinert, Tobias [Paul Scherrer Institute, Villigen PSI (Switzerland); Schulze-Briese, Clemens [Dectris Ltd, Baden 5400 (Switzerland); Wang, Meitian, E-mail: vincent.olieric@psi.ch [Paul Scherrer Institute, Villigen PSI (Switzerland)

    2015-05-09

    The design and performance of the new multi-axis goniometer PRIGo developed at the Swiss Light Source at Paul Scherrer Institute is described. The Parallel Robotics Inspired Goniometer (PRIGo) is a novel compact and high-precision goniometer providing an alternative to (mini-)kappa, traditional three-circle goniometers and Eulerian cradles used for sample reorientation in macromolecular crystallography. Based on a combination of serial and parallel kinematics, PRIGo emulates an arc. It is mounted on an air-bearing stage for rotation around ω and consists of four linear positioners working synchronously to achieve x, y, z translations and χ rotation (0–90°), followed by a ϕ stage (0–360°) for rotation around the sample holder axis. Owing to the use of piezo linear positioners and active correction, PRIGo features spheres of confusion of <1 µm, <7 µm and <10 µm for ω, χ and ϕ, respectively, and is therefore very well suited for micro-crystallography. PRIGo enables optimal strategies for both native and experimental phasing crystallographic data collection. Herein, PRIGo hardware and software, its calibration, as well as applications in macromolecular crystallography are described.

  13. Feasibility and optical performance of one axis three positions sun-tracking polar-axis aligned CPCs for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Runsheng; Yu, Yamei [Education Ministry Key Laboratory of Advanced Technology and Preparation for Renewable Energy Materials, Yunnan Normal University, Kunming 650092 (China)

    2010-09-15

    A new design concept, called one axis three positions sun-tracking polar-axis aligned CPCs (3P-CPCs, in short), was proposed and theoretically studied in this work for photovoltaic applications. The proposed trough-like CPC is oriented in the polar-axis direction, and the aperture is daily adjusted eastward, southward, and westward in the morning, noon and afternoon, respectively, by rotating the CPC trough, to ensure efficient collection of beam radiation nearly all day. To investigate the optical performance of such CPCs, an analytical mathematical procedure is developed to estimate daily and annual solar gain captured by such CPCs based on extraterrestrial radiation and monthly horizontal radiation. Results show that the acceptance half-angle of 3P-CPCs is a unique parameter to determine their optical performance according to extraterrestrial radiation, and the annual solar gain stays constant if the acceptance half-angle, {theta}{sub a}, is less than one third of {omega}{sub 0,min}, the sunset hour angle in the winter solstice, otherwise decreases with the increase of {theta}{sub a}. For 3P-CPCs used in China, the annual solar gain, depending on the climatic conditions in site, decreased with the acceptance half-angle, but such decrease was slow for the case of {theta}{sub a}{<=}{omega}{sub 0,min}/3, indicating that the acceptance half-angle should be less than one third of {omega}{sub 0,min} for maximizing annual energy collection. Compared to fixed east-west aligned CPCs (EW-CPCs) with a yearly optimal acceptance half-angle, the fixed south-facing polar-axis aligned CPCs (1P-CPCs) with the same acceptance half-angle as the EW-CPCs annually collected about 65-74% of that EW-CPCs did, whereas 3P-CPCs annually collected 1.26-1.45 times of that EW-CPCs collected, indicating that 3P-CPCs were more efficient for concentrating solar radiation onto their coupling solar cells. (author)

  14. Optical performance of inclined south-north single-axis tracked solar panels

    International Nuclear Information System (INIS)

    To investigate optical performance of the inclined south-north single-axis (ISN-axis, in short) tracked solar panels, a mathematical procedure to estimate the annual collectible radiation on fixed and tracked panels was suggested based on solar geometry and monthly horizontal radiation. For solar panels tracking about ISN-axis, the yearly optimal tilt-angle of ISN-axis for maximizing annual solar gain was about 3o deviating from the site latitude in most of China except in areas with poor solar resources, and the maximum annual collectible radiation on ISN-axis tracked panels was about 97-98% of that on dual-axis tracked panels; whereas for ISN-axis tracked panels with the tilt-angle of ISN-axis being adjusted four times in a year at three fixed tilt-angles, the annual collectible radiation was almost close to that on dual-axis tracked panels, the optimum date of tilt-angle adjustment of ISN-axis was 23 days from the equinoxes, and the optimum tilt-angle adjustment value for each adjustment was about 22o. Compared to fixed south-facing solar panels inclined at an optimal tilt-angle, the increase in the annual solar gain due to using ISN-axis sun tracking was above 30% in the areas with abundant solar resources and less than 20% in the areas with poor solar resources.

  15. The Mechanical Axis of the First Ray: A Radiographic Assessment in Hallux Abducto Valgus Evaluation.

    Science.gov (United States)

    LaPorta, Guido A; Nasser, Ellianne M; Mulhern, Jennifer L; Malay, D Scot

    2016-01-01

    The present report describes a new method of hallux abducto valgus deformity correction planning using the mechanical axis of the medial column (mechanical axis planning). This method of radiographic evaluation identifies an ideal position for the first metatarsal after correction and is useful regardless of the surgical procedure chosen. We retrospectively reviewed 200 radiographs to identify a "normal" value for the mechanical axis angle. We reviewed 100 radiographs of patients with hallux abducto valgus deformity (deformity group) and 100 radiographs of patients without hallux abducto valgus deformity (control group). The deformity group revealed an M1-M2 anatomic axis angle of 13.5° ± 2.83° and an M1-M2 mechanical axis angle of 11.58° ± 1°. The control group revealed an M1-M2 anatomic axis angle of 7.5° ± 1.76° and an M1-M2 mechanical axis angle of 11.19° ± 0.9°. The differences in the M1-M2 anatomic axis angle and M1-M2 mechanical axis angle were statistically significant between the control and deformity groups. We sought to provide a reliable method for planning hallux abducto valgus deformity correction by aligning the mechanical axis of the medial column and the mechanical axis of the first ray to the "normal" value of 11° to reduce the deformity.

  16. Dual axis translation apparatus and system for translating an optical beam and related method

    Science.gov (United States)

    Cassidy, Kelly

    1991-01-01

    A dual axis translation device and system in accordance with this invention, for translating an optical beam along both an x-axis and a y-axis which are perpendicular to one another, has a beam directing means acting on said optical beam for directing the beam along a particular path transverse to said x and y axes. An arrangement supporting said beam directing means for movement in the x and y direction within a given plane is provided. The arrangement includes a first means for translating said beam directing means along the x-axis in said given plane in order to translate the beam along said x-axis. The arrangement comprises a second means for translating said beam directing means along the y-axis in said given plane in order to translate the beam along said y-axis.

  17. On steady rotations of a rigid body bearing a single-axis powered gyroscope whose precession axis is parallel to a principal plane of inertia

    NARCIS (Netherlands)

    Amel'kin, N. I.

    2009-01-01

    The set of steady motions of the system named in the title is represented parametrically via the gyro gimbal rotation angle for an arbitrary position of the gimbal axis. We study the set of steady motions for a system in which the gyro gimbal axis is parallel to a principal plane of inertia as well

  18. Equilibrium reconstruction for Single Helical Axis reversed field pinch plasmas

    CERN Document Server

    Martines, Emilio; Momo, Barbara; Terranova, David; Zanca, Paolo; Alfier, Alberto; Bonomo, Federica; Canton, Alessandra; Fassina, Alessandro; Franz, Paolo; Innocente, Paolo

    2011-01-01

    Single Helical Axis (SHAx) configurations are emerging as the natural state for high current reversed field pinch (RFP) plasmas. These states feature the presence of transport barriers in the core plasma. Here we present a method for computing the equilibrium magnetic surfaces for these states in the force-free approximation, which has been implemented in the SHEq code. The method is based on the superposition of a zeroth order axisymmetric equilibrium and of a first order helical perturbation computed according to Newcomb's equation supplemented with edge magnetic field measurements. The mapping of the measured electron temperature profiles, soft X-ray emission and interferometric density measurements on the computed magnetic surfaces demonstrates the quality of the equilibrium reconstruction. The procedure for computing flux surface averages is illustrated, and applied to the evaluation of the thermal conductivity profile. The consistency of the evaluated equilibria with Ohm's law is also discussed.

  19. The plasma boundary in Single Helical Axis RFP plasmas

    CERN Document Server

    Martines, E; Momo, B; Munaretto, S; Innocente, P; Spolaore, M

    2009-01-01

    Single Helical Axis (SHAx) states obtained in high current reversed field pinch (RFP) plasmas display, aside from a dominant mode in the m=1 spectrum, also a dominant m=0 mode, with the same toroidal mode number as the m=1 one. The two modes have a fixed phase relationship. The island chain created by the m=0 mode across the reversal surface gives rise, at shallow reversal of the toroidal field, to an X-point structure which separates the last closed flux surface from the first wall, creating a divertor-like configuration. The plasma-wall interaction is found to be related to the connection length of the field lines intercepting the wall, which displays a pattern modulated by the dominant mode toroidal periodicity. This configuration, which occurs only for shallow toroidal field reversal, could be exploited to realize an island divertor in analogy to stellarators.

  20. Equilibrium reconstruction for single helical axis reversed field pinch plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Martines, E; Lorenzini, R; Momo, B; Terranova, D; Zanca, P; Alfier, A; Bonomo, F; Canton, A; Fassina, A; Franz, P; Innocente, P, E-mail: emilio.martines@igi.cnr.it [Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, corso Stati Uniti 4, 35127 Padova (Italy)

    2011-03-15

    Single helical axis configurations are emerging as the natural state for high-current reversed field pinch plasmas. These states feature the presence of transport barriers in the core plasma. Here we present a method for computing the equilibrium magnetic surfaces for these states in the force-free approximation, which has been implemented in the SHEq code. The method is based on the superposition of a zeroth-order axisymmetric equilibrium and of a first-order helical perturbation computed according to Newcomb's equation supplemented with edge magnetic field measurements. The mapping of the measured electron temperature profiles, soft x-ray emission and interferometric density measurements on the computed magnetic surfaces demonstrates the quality of the equilibrium reconstruction. The procedure for computing flux surface averages is illustrated, and applied to the evaluation of the thermal conductivity profile. The consistency of the evaluated equilibria with Ohm's law is also discussed.

  1. Software tool for horizontal-axis wind turbine simulation

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, A.J. [Instituto Argentino de Oceanografia, Camino La Carrindanga Km. 7, 5 CC 804, B8000FWB Bahia Blanca (Argentina); Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Dpto. de Ing. Electrica y de Computadoras, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Rossi, A.P. [Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Dpto. de Ing. Electrica y de Computadoras, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

    2008-07-15

    The main problem of a wind turbine generator design project is the design of the right blades capable of satisfying the specific energy requirement of an electric system with optimum performance. Once the blade has been designed for optimum operation at a particular rotor angular speed, it is necessary to determine the overall performance of the rotor under the range of wind speed that it will encounter. A software tool that simulates low-power, horizontal-axis wind turbines was developed for this purpose. With this program, the user can calculate the rotor power output for any combination of wind and rotor speeds, with definite blade shape and airfoil characteristics. The software also provides information about distribution of forces along the blade span, for different operational conditions. (author)

  2. New airfoils for small horizontal axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Giguere, P.; Selig, M.S. [Univ. of Illinois, Urbana, IL (United States)

    1997-12-31

    In a continuing effort to enhance the performance of small energy systems, one root airfoil and three primary airfoils were specifically designed for small horizontal axis wind turbines. These airfoils are intended primarily for 1-10 kW variable-speed wind turbines for both conventional (tapered/twisted) or pultruded blades. The four airfoils were wind-tunnel tested at Reynolds numbers between 100,000 and 500,000. Tests with simulated leading-edge roughness were also conducted. The results indicate that small variable-speed wind turbines should benefit from the use of the new airfoils which provide enhanced lift-to-drag ratio performance as compared with previously existing airfoils.

  3. Development of Rotary Axis For Wire Electrical Discharge Machining (WEDM

    Directory of Open Access Journals (Sweden)

    M. Parthiban, C. Manigandan, G. Muthu Venkadesh, M. Ranjith Kumar

    2013-08-01

    Full Text Available This paper gives an overview of setting up a rotary axis to the existing WEDM machine to investigate the machining parameters in WEDG of harder materials. There are a number of hybrid machining processes (HMPs seeking the combined advantage of EDM and other machining techniques. One such combination is wire electrical discharge grinding (WEDG, which is commonly used for micro-machining of fine and hard rods. WEDG employs a single wire guide to confine the wire tension within the discharge area between the rod and the front edge of the wire and also to minimize the wire vibration. Other advantages of WEDG include the ability to machine hard- to- machine materials with large aspect ratio.

  4. The enteroinsular axis in dipeptidyl peptidase IV-negative rats

    DEFF Research Database (Denmark)

    Pederson, Raymond; Kieffer, T J; Pauly, R;

    1996-01-01

    were used in the current investigation as a model for examining the enteroinsular axis under conditions in which normal inactivation of GIP and GLP-1(7-36) does not occur. This was assessed by comparing GIP and GLP-1(7-36) responses following oral glucose in normal versus DPIV-deficient Fischer rats......Evidence has accumulated that the incretins glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1(7-36) amide) are degraded and rendered biologically inactive in plasma by the enzyme dipeptidyl peptidase IV (DPIV). A strain of Fischer rats lacking the DPIV enzyme......, and by comparing the insulinotropic potency of both peptides in the perfused pancreas of both groups. The insulin response to an oral glucose challenge was decreased slightly in DPIV-negative rats compared with control animals. Of the two incretins, the GIP response to oral glucose was reduced by 50% compared...

  5. A Multi-Fork Z-Axis Quartz Micromachined Gyroscope

    Directory of Open Access Journals (Sweden)

    Aiying Yang

    2013-09-01

    Full Text Available A novel multi-fork z-axis gyroscope is presented in this paper. Different from traditional quartz gyroscopes, the lateral electrodes of the sense beam can be arranged in simple patterns; as a result, the fabrication is simplified. High sensitivity is achieved by the multi-fork design. The working principles are introduced, while the finite element method (FEM is used to simulate the modal and sensitivity. A quartz fork is fabricated, and a prototype is assembled. Impedance testing shows that the drive frequency and sense frequency are similar to the simulations, and the quality factor is approximately 10,000 in air. The scale factor is measured to be 18.134 mV/(°/s and the nonlinearity is 0.40% in a full-scale input range of ±250 °/s.

  6. Development and demonstration of a vertical axis wind turbine POWERHOUSE

    Science.gov (United States)

    Vosburgh, P. N.

    1984-06-01

    A performance of reliable lower cost base assembly and controls was designed for the electricity generating wind energy conversion system of the VAWTPOWER 185 wind turbine. The base assembly includes low speed shaft and couplings, disc or drum brake, hydraulic or pneumatic brake control systems, speed increasing gear box, high speed shaft and couplings, induction motor/generator, bottom rotor bearings, lightning and ground fault protection, support structure, and environmental protection. VAWTPOWER 185 is a 200 kW capacity Vertical Axis Wind Turbine rated 185 kW at 37 mph. After system analysis, subsystem definition, detailed design and engineering, and development of a test plan, two versions of the powerhouse were fabricated and tested. Both appear ready for commercial production.

  7. The Kidney-Gut Axis: Implications for Nutrition Care.

    Science.gov (United States)

    Rossi, Megan; Johnson, David W; Campbell, Katrina L

    2015-09-01

    There is increasing clinical evidence that patients with chronic kidney disease (CKD) have a distinctly dysbiotic intestinal bacterial community, termed the gut microbiota, which in turn drives a cascade of metabolic abnormalities, including uremic toxin production, inflammation, and immunosuppression, that ultimately promotes progressive kidney failure and cardiovascular disease. As the gut microbiota is intimately influenced by diet, the discovery of the kidney-gut axis has created new therapeutic opportunities for nutritional intervention. This review discusses the metabolic pathways linking dysbiotic gut microbiota with adverse health outcomes in patients with CKD, as well as novel therapeutic strategies for targeting these pathways involving dietary protein, fiber, prebiotics, probiotics, and synbiotics. These emerging nutritional interventions may ultimately lead to a paradigm shift in the conventional focus of dietary management in CKD. PMID:25812908

  8. Active Circulation Control for Horizontal Axis Wind Turbine

    Science.gov (United States)

    Dumitrache, Alexandru; Dumitrescu, Horia; Preotu, Octavian

    2011-09-01

    A based method for modeling the aerodynamics of horizontal axis wind turbine has been developed. Circulation control is implemented by tangentially blowing a small high-velocity jet over a highly curved surface, such as a rounded trailing edge. This causes the boundary layer and the jet sheet to remain attached along the curved surface due to the Coanda effect and causing the jet to turn without separation. This analysis has been validated for the experimental data of a rotor tested at NASA Ames Research Center. Comparisons have been done against measurements for surface pressure distribution, force coefficients normal and tangential to the chord line, torque and root bending moments. This approach for enhancing the circulation around the airfoil sections (and hence L/D and power production) has been examined and found to produce useful increases in power at low wind speeds.

  9. IDENTIFICATION OF GYRO DRIFTS UNDER THREE AXIS ATTITUDE COUPLING

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Optical gyros and star sensors are primary measurement hardware in an attitude control system with high accuracy.The drifts of the optical gyros, however, make an unfavorable impact on the accuracy of the attitude control system.In order for compensations to be provided, this paper presents a least-square method to identify the optical gyro drifts by using flight attitude data from the star sensors and the optical gyros.Equations for identification are formulated by quaternion.Integration of the identification equations and the data from the star sensors are utilized to form a least-square index, in which lower sampling frequency of the star sensors than that of the optical gyros is dealt with effectively.An iterative identification algorithm is presented to minimize the index.Identification procedure under three-axis attitude coupling is illustrated .Simulation results show the effectiveness of the method presented.Proper sample size and sampling frequency are also recommended.

  10. Optimization model for rotor blades of horizontal axis wind turbines

    Institute of Scientific and Technical Information of China (English)

    LIU Xiong; CHEN Yan; YE Zhiquan

    2007-01-01

    This paper presents an optimization model for rotor blades of horizontal axis wind turbines. The model refers to the wind speed distribution function on the specific wind site, with an objective to satisfy the maximum annual energy output. To speed up the search process and guarantee a global optimal result, the extended compact genetic algorithm (ECGA) is used to carry out the search process.Compared with the simple genetic algorithm, ECGA runs much faster and can get more accurate results with a much smaller population size and fewer function evaluations. Using the developed optimization program, blades of a 1.3 MW stall-regulated wind turbine are designed. Compared with the existing blades, the designed blades have obviously better aerodynamic performance.

  11. Dynamic stall occurrence on a horizontal axis wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Shipley, D.E.; Miller, M.S.; Robinson, M.C. [Colorado Univ., Boulder, CO (United States). Dept. of Aerospace Engineering Sciences

    1995-07-01

    Surface pressure data from the National Renewable Energy Laboratory`s ``Combined Experiment`` were analyzed to provide a statistical representation of dynamic stall occurrence on a downwind horizontal axis wind turbine (HAWT). Over twenty thousand blade rotational cycles were each characterized at four span locations by the maximum leading edge suction pressure and by the azimuth, velocity, and yaw at which it occurred. Peak suction values at least twice that seen in static wind tunnel tests were taken to be indicative of dynamic stall. The occurrence of dynamic stall at all but the inboard station (30% span) shows good quantitative agreement with the theoretical limits on inflow velocity and yaw that should yield dynamic stall. Two hypotheses were developed to explain the discrepancy at 30% span. Estimates are also given for the frequency of dynamic stall occurrence on upwind turbines. Operational regimes were identified which minimize the occurrence of dynamic stall events.

  12. An electromagnetically levitated two-axis gimbaless pointing mechanism

    Science.gov (United States)

    Volpe, Gerald T.

    A brief description for a proposed new pointing mechanism which requires no mechanical gimbals, is virtually friction free, and is vibration isolated from a ground support system or vehicle is presented. The device uses electromagnetic forces for support levitation and pointing, both being accomplished from a ground reference thereby leaving the payload virtually free from a remotely located command center. Solid pointing angles of almost 2(pi) steradians are achievable, limited only by structural interference. A third degree-of-freedom tilt axis can be added at will, but will not be elaborated. Although the system is primarily intended for space vehicles in a micro-gravity environment, earth-ground support is possible with superconducting electromagnets.

  13. Nonlinear characterization of a single-axis acoustic levitator

    Science.gov (United States)

    Andrade, Marco A. B.; Ramos, Tiago S.; Okina, Fábio T. A.; Adamowski, Julio C.

    2014-04-01

    The nonlinear behavior of a 20.3 kHz single-axis acoustic levitator formed by a Langevin transducer with a concave radiating surface and a concave reflector is experimentally investigated. In this study, a laser Doppler vibrometer is applied to measure the nonlinear sound field in the air gap between the transducer and the reflector. Additionally, an electronic balance is used in the measurement of the acoustic radiation force on the reflector as a function of the distance between the transducer and the reflector. The experimental results show some effects that cannot be described by the linear acoustic theory, such as the jump phenomenon, harmonic generation, and the hysteresis effect. The influence of these nonlinear effects on the acoustic levitation of small particles is discussed.

  14. Parametric study of single-axis acoustic levitation

    Energy Technology Data Exchange (ETDEWEB)

    Xie, W. J.; Wei, B.

    2001-08-06

    Remarkable enhancement of the single-axis acoustic levitation force is achieved by properly curving the surface and enlarging the section of the reflector so as to levitate high density material like tungsten ({rho}{sub s}=18.92g/cm{sup 3}). A two-cylinder model incorporating the boundary element method simulations is presented for systematic study of the relationship between levitation capabilities and geometric parameters. The model proves to be successful in predicting resonant modes and explaining deviation of the levitated samples near the reflector and driver. The dependence of levitation force on resonant mode, reflector section radius R{sub b} and curvature radius R is revealed and summarized, which agrees with the experiment in principle and suggests that a reflector with large R{sub b} and small R (when R{sub b}/{lambda}{>=}0.982) working under mode 1 assures better levitation capabilities. {copyright} 2001 American Institute of Physics.

  15. Lightcurves and the axis of rotation of 433 Eros

    Science.gov (United States)

    Dunlap, J. L.

    1976-01-01

    Ten lightcurves and UBV photometry of 433 Eros were obtained between August 1972 and May 1975. The absolute magnitude of the lightcurve maximum is 10.75 and the phase coefficient is 0.025 mag/deg. There may be a small difference in B-V color between the northern and southern hemispheres. The pole of the axis of rotation is directed toward 16 deg, ecliptic longitude and 12 deg ecliptic latitude, respectively, and the rotation is direct with a sidereal period of 5 hr 16 min 13.4 sec. The dimensions derived from the polarimetric albedo and the lightcurve amplitudes are 12 km by 12 km by 31 km for a smooth cylinder with hemispherical ends.

  16. A multi-fork z-axis quartz micromachined gyroscope.

    Science.gov (United States)

    Feng, Lihui; Zhao, Ke; Sun, Yunan; Cui, Jianmin; Cui, Fang; Yang, Aiying

    2013-01-01

    A novel multi-fork z-axis gyroscope is presented in this paper. Different from traditional quartz gyroscopes, the lateral electrodes of the sense beam can be arranged in simple patterns; as a result, the fabrication is simplified. High sensitivity is achieved by the multi-fork design. The working principles are introduced, while the finite element method (FEM) is used to simulate the modal and sensitivity. A quartz fork is fabricated, and a prototype is assembled. Impedance testing shows that the drive frequency and sense frequency are similar to the simulations, and the quality factor is approximately 10,000 in air. The scale factor is measured to be 18.134 mV/(°/s) and the nonlinearity is 0.40% in a full-scale input range of ±250 °/s.

  17. Nonlinear characterization of a single-axis acoustic levitator

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marco A. B. [Institute of Physics, University of São Paulo, São Paulo (Brazil); Ramos, Tiago S.; Okina, Fábio T. A.; Adamowski, Julio C. [Department of Mechatronics and Mechanical Systems Engineering, Escola Politécnica, University of São Paulo, São Paulo (Brazil)

    2014-04-15

    The nonlinear behavior of a 20.3 kHz single-axis acoustic levitator formed by a Langevin transducer with a concave radiating surface and a concave reflector is experimentally investigated. In this study, a laser Doppler vibrometer is applied to measure the nonlinear sound field in the air gap between the transducer and the reflector. Additionally, an electronic balance is used in the measurement of the acoustic radiation force on the reflector as a function of the distance between the transducer and the reflector. The experimental results show some effects that cannot be described by the linear acoustic theory, such as the jump phenomenon, harmonic generation, and the hysteresis effect. The influence of these nonlinear effects on the acoustic levitation of small particles is discussed.

  18. Dynamic behavior analysis for a six axis industrial machining robot

    CERN Document Server

    Bisu, Claudiu-Florinel; Gérard, Alain; K'Nevez, Jean-Yves

    2012-01-01

    The six axis robots are widely used in automotive industry for their good repeatability (as defined in the ISO92983) (painting, welding, mastic deposition, handling etc.). In the aerospace industry, robot starts to be used for complex applications such as drilling, riveting, fiber placement, NDT, etc. Given the positioning performance of serial robots, precision applications require usually external measurement device with complexes calibration procedure in order to reach the precision needed. New applications in the machining field of composite material (aerospace, naval, or wind turbine for example) intend to use off line programming of serial robot without the use of calibration or external measurement device. For those applications, the position, orientation and path trajectory precision of the tool center point of the robot are needed to generate the machining operation. This article presents the different conditions that currently limit the development of robots in robotic machining applications. We ana...

  19. K-shell ionization under zone axis electron diffraction conditions

    International Nuclear Information System (INIS)

    A comprehensive theoretical treatment for the inelastic scattering of fast electrons in a crystalline environment is applied to account for variations in characteristic x-ray emission rates from spinel and chromia under zone axis diffraction conditions for 300 keV electrons. X-ray counts as well as backscattered electron contrast are recorded as the beam is tilted by about 70 mrad on a two-dimensional scan raster. Calculated K-shell ionization and backscattering cross sections, based on a model which takes into account interaction delocalization, thermal diffuse scattering and the consequent thickness dependent channelling effects in a realistic way, are in good agreement with experiment. 43 refs., 13 figs

  20. The Gut-Lung Axis in Respiratory Disease.

    Science.gov (United States)

    Marsland, Benjamin J; Trompette, Aurélien; Gollwitzer, Eva S

    2015-11-01

    Host-microorganism interactions shape local cell functionality, immune responses, and can influence disease development. Evidence indicates that the impact of host-microbe interactions reaches far beyond the local environment, thus influencing responses in peripheral tissues. There is a vital cross-talk between the mucosal tissues of our body, as exemplified by intestinal complications during respiratory disease and vice versa. Although, mechanistically, this phenomenon remains poorly defined, the existence of the gut-lung axis and its implications in both health and disease could be profoundly important for both disease etiology and treatment. In this review, we highlight how changes in the intestinal microenvironment, with a particular focus on the intestinal microbiota, impact upon respiratory disease.

  1. Strain measurements in ferromagnetic martensitic Heuslers and magnetization easy axis

    Energy Technology Data Exchange (ETDEWEB)

    Aksoy, Seda; Acet, Mehmet; Wassermann, Eberhard F. [Experimentalphysik, Universitaet Duisburg-Essen, Duisburg (Germany)

    2008-07-01

    The temperature-dependence of strain under constant magnetic-fields is studied in Ni-Mn-X (X:Ga,In,Sn,Sb) and Ni-Mn-In-X (X:Ga,Sn,Sb) polycrystalline ferromagnetic Heusler alloys which undergo a martensitic transformation close to room-temperature. The applied magnetic-field influences the nucleation of martensite so that decreasing the temperature under a magnetic field leads to large length changes between the austenite and martensite states. The length-change within the martensitic state varies with the magnitude of the cooling-field. This is related to the variant-orientation during martensite nucleation. These strain-data provide information on the easy axis of magnetization.

  2. Design and Analysis of Horizontal Axis Wind Turbine Rotor

    Directory of Open Access Journals (Sweden)

    Arvind Singh Rathore

    2011-11-01

    Full Text Available This paper presents an optimization model for rotor design of 750 kW horizontal axis wind turbine. The wind turbine blade is a very important part of the rotor. In this work a blade of length 21.0 m is taken and airfoil for the blade is S809. The airfoil taken is same from root to tip. The model refers to a design method based on TypeApproval Provision Scheme TAPS-2000. All the loads caused by wind and inertia on the blades are transferred to the hub. The stress and deflection were calculated on blades and hub by Finite element analysis method. Result obtained from ANSYS is compared with the existing design.

  3. Aerodynamic performance of vertical and horizontal axis wind turbines

    Science.gov (United States)

    Maydew, R. C.; Klimas, P. C.

    1981-06-01

    The aerodynamic performance of vertical and horizontal axis wind turbines is investigated, and comparison of data of the 17-m Darrieus VAWT with the 60.7-m Mod-1 HAWT and 37.8-m Mod-0A HAWT is discussed. It is concluded that the maximum average measured power coefficients of the VAWT are about 0%-15% higher than those of the HAWTs. It is suggested that vertical wind shear may have lowered the Mod-1 HAWT aerodynamic performance, but, the magnitude of this effect could not be evaluated. It is included that generalizations which refer to the Darrieus VAWT as aerodynamically less efficient than the HAWT should be used carefully.

  4. Specification of anteroposterior axis by combinatorial signaling during Xenopus development.

    Science.gov (United States)

    Carron, Clémence; Shi, De-Li

    2016-01-01

    The specification of anteroposterior (AP) axis is a fundamental and complex patterning process that sets up the embryonic polarity and shapes a multicellular organism. This process involves the integration of distinct signaling pathways to coordinate temporal-spatial gene expression and morphogenetic movements. In the frog Xenopus, extensive embryological and molecular studies have provided major advance in understanding the mechanism implicated in AP patterning. Following fertilization, cortical rotation leads to the transport of maternal determinants to the dorsal region and creates the primary dorsoventral (DV) asymmetry. The activation of maternal Wnt/ß-catenin signaling and a high Nodal signal induces the formation of the Nieuwkoop center in the dorsal-vegetal cells, which then triggers the formation of the Spemann organizer in the overlying dorsal marginal zone. It is now well established that the Spemann organizer plays a central role in building the vertebrate body axes because it provides patterning information for both DV and AP polarities. The antagonistic interactions between signals secreted in the Spemann organizer and the opposite ventral region pattern the mesoderm along the DV axis, and this DV information is translated into AP positional values during gastrulation. The formation of anterior neural tissue requires simultaneous inhibition of zygotic Wnt and bone morphogenetic protein (BMP) signals, while an endogenous gradient of Wnt, fibroblast growth factors (FGFs), retinoic acid (RA) signaling, and collinearly expressed Hox genes patterns the trunk and posterior regions. Collectively, DV asymmetry is mostly coupled to AP polarity, and cell-cell interactions mediated essentially by the same regulatory networks operate in DV and AP patterning. For further resources related to this article, please visit the WIREs website. PMID:26544673

  5. Thyroid axis activity and suicidal behavior in depressed patients.

    Science.gov (United States)

    Duval, Fabrice; Mokrani, Marie-Claude; Lopera, Felix Gonzalez; Diep, Thanh Son; Rabia, Hassen; Fattah, Saïd

    2010-08-01

    The aim of this study was to investigate the relationship between suicidal behavior and hypothalamic-pituitary thyroid (HPT) axis activity in depressed patients. The serum levels of thyrotropin (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were evaluated before and after 0800 and 2300 h thyrotropin-releasing hormone (TRH) challenges, on the same day, in 95 medication-free DSM-IV euthyroid major depressed inpatients and 44 healthy hospitalized controls. Compared to controls: (1) patients with a positive suicide history (PSH; n=53) showed lower basal FT4 (at 0800 h: p<0.005; at 2300 h: p<0.03), but normal FT3 levels, while patients with a negative suicide history (NSH; n=42) showed normal FT4 and FT3 levels; (2) TSH responses to TRH (DeltaTSH) were blunted in NSHs (at 0800 h: p<0.03; at 2300 h: p<0.00001), but not in PSHs; (3) both NSHs and PSHs showed lower DeltaDeltaTSH values (differences between 2300 h-DeltaTSH and 0800 h-DeltaTSH) (p<0.000001 and p<0.003, respectively). Compared to NSHs, basal FT4 levels were reduced in PSHs (at 0800 h: p<0.002; at 2300h: p<0.006). HPT parameters were not significantly different between recent suicide attempters (n=32) and past suicide attempters (n=21). However, compared to controls, recent suicide attempters showed lower 2300 h-DeltaTSH (p<0.04) and DeltaDeltaTSH (p<0.002) values, and lower basal FT4 values (at 0800 h: p<0.006; at 2300 h: p<0.02). Our results, obtained in a large sample of depressed inpatients, indicate that various degrees of HPT axis dysregulation are associated with the history of suicide. PMID:20129737

  6. IR Spectrometer Using 90-degree Off-axis Parabolic Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Malone, Richard, G. Hacking, Ian J. McKenna, and Daniel H. Dolan

    2008-09-02

    A gated spectrometer has been designed for real-time, pulsed infrared (IR) studies at the National Synchrotron Light ource at the Brookhaven National Laboratory. A pair of 90-degree, off-axis parabolic mirrors are used to relay the light from an entrance slit to an output IR recording camera. With an initial wavelength range of 1500–4500 nm required, gratings could not be used in the spectrometer because grating orders would overlap. A magnesium oxide prism, placed between these parabolic mirrors, serves as the dispersion element. The spectrometer is doubly telecentric. With proper choice of the air spacing between the prism and the second parabolic mirror, any spectral region of interest within the InSb camera array’s sensitivity region can be recorded. The wavelengths leaving the second parabolic mirror are collimated, thereby relaxing the camera positioning tolerance. To set up the instrument, two different wavelength (visible) lasers are introduced at the entrance slit and made collinear with the optical axis via flip mirrors. After dispersion by the prism, these two laser beams are directed to tick marks located on the outside housing of the gated IR camera. This provides first-order wavelength calibration for the instrument. Light that is reflected off the front prism face is coupled into a high-speed detector to verify steady radiance during the gated spectral imaging. Alignment features include tick marks on the prism and parabolic mirrors. This instrument was designed to complement singlepoint pyrometry, which provides continuous time histories of a small collection of spots from shock-heated targets.

  7. Short-axis epicardial volume change is a measure of cardiac left ventricular short-axis function, which is independent of myocardial wall thickness.

    Science.gov (United States)

    Ugander, Martin; Carlsson, Marcus; Arheden, Håkan

    2010-02-01

    Fractional shortening (FS) by echocardiography is considered to represent the short-axis contribution to the stroke volume (SV), also called short-axis function. However, FS is mathematically coupled to the amount of myocardium, since it rearranges during atrioventricular plane displacement (AVPD). The SV is the sum of the volumes generated by 1) reduction in outer volume of the heart, and 2) inner AVPD. The long-axis contribution to the SV is generated by AVPD, and thus the short-axis contribution is the remaining outer volume change of the heart, which should be unrelated to myocardial wall thickness. We hypothesized that both endocardial and midwall shortening indexed to SV are dependent on myocardial wall thickness, whereas epicardial volume change (EVC) indexed to SV is not. Twelve healthy volunteers (normals), 12 athletes, and 12 patients with dilated cardiomyopathy (ejection fraction EVC was defined as SV minus long-axis function. Endocardial and midwall shortening were measured in a midventricular short-axis slice. Endocardial shortening/SV and midwall shortening/SV both varied in relation to end-diastolic myocardial wall thickness (R(2) = 0.16, P = 0.008 and R(2) = 0.14, P = 0.012, respectively), whereas EVC/SV did not (R(2) = 0.00, P = 0.37). FS is dependent on myocardial wall thickness, whereas EVC is not and therefore represents true short-axis function. This is not surprising considering that FS is mainly caused by rearrangement of myocardium secondary to long-axis function. FS is therefore not synonymous with short-axis function.

  8. Deflecting Easy-axis of Fe304 Single Crystal Nanowires by Magnetic-field-induced Method

    Institute of Scientific and Technical Information of China (English)

    W. Wang; S. Y. Wang

    2012-01-01

    In order to control the orientation of easy-axis of magnetic nanowires, FesO4 single crystal nanowires with easy-axis perpendicular to wire-axis were prepared successfully by means of a magnetic-field-induced method. Analysis of X-ray diffraction and electron diffraction pattern showed that there was a wide-angle deflection of easy-axis in the prepared Fe304 nanowires. A high saturation magnetization (82 emu/g) of the FesO4 nanowires was achieved at room temperature. The benefits and mechanism of the deflection of easy-axis from its wire-axis in FesO4 single crystal nanowires were discussed. The results are expected to broaden the magnetic properties of traditional ferrite nanowires.

  9. Suppression of the HPA Axis Stress-Response: Implications for Relapse

    OpenAIRE

    Adinoff, Bryon; Junghanns, Klaus; Kiefer, Falk; Krishnan-Sarin, Suchitra

    2005-01-01

    This article presents the proceedings of a symposium held at the meeting of the International Society for Biomedical Research on Alcoholism (ISBRA) in Mannheim, Germany, in October 2004. This symposium explored the potential role of hypothalamic-pituitary-adrenal (HPA) axis dysregulation upon relapse. HPA axis stimulation induces the release of the glucocorticoid cortisol, a compound with profound effects upon behavior and emotion. Altered stress-responses of the HPA axis in abstinent alcohol...

  10. OPTIMISE - Deliverable D4.3 Report on two axis rolling, month 12

    DEFF Research Database (Denmark)

    Eriksen, Morten

    This report is one of two reports which describe de deliverables on two axis rolling in the OPTIMISE project. Most of the work in this report has also been described in the sub work package reports produced during the project. The sub work package reports are WP4.1 Two axis rolling and WP4.3 Fini...... Element Modelling of two axis rolling....

  11. Analisis Semiotika Makna Pesan pada Iklan Axis Versi “Iritologi – Menatap Masa Depan”

    OpenAIRE

    Puri Sulistiyawati

    2016-01-01

    Abstrak Tujuan dari penelitian ini adalah untuk mengetahui dan menganalisis makna pesan dalam iklan Axis versi “Iritologi – Menatap masa depan” di televisi dengan menggunakan pendekatan semiotika Roland Barthes. Dari analisis yang telah dilakukan berdasarkan makna denotasi, konotasi dan mitos dalam iklan Axis versi “iritologi – Menatap masa depan”, dapat diketahui bahwa iklan Axis memiliki konsep yang sangat sederhana, dengan mengusung tema tentang kebiasaan remaja dalam memanfaatkan media s...

  12. Electromechanical three-axis development for remote handling in the Hot Experimental Facility

    International Nuclear Information System (INIS)

    A three-axis closed-loop position control system has been designed and installed on an overhead bridge, carriage, tube hoist for automotive positioning of manipulation at a remotely maintained work site. The system provides accurate (within 3 min) and repeatable three-axis positioning of the manipulator. The position control system has been interfaced to a supervisory minicomputer system that provides teach-playback capability of manipulator positioning and color graphic display of the three-axis system position

  13. Charged current disappearance measurements in the NuMI off-axis beam

    Energy Technology Data Exchange (ETDEWEB)

    R. H. Bernstein

    2003-09-25

    This article studies the potential of combining charged-current disappearance measurements of {nu}{sub {mu}} {yields} {nu}{sub {tau}} from MINOS and an off-axis beam. The author finds that the error on {Delta}m{sup 2} from a 100 kt-yr off-axis measurement is a few percent of itself. Further, the author found little improvement to an off-axis measurement by combining it with MINOS.

  14. THE MICROBIOTA-GUT-BRAIN AXIS. A STUDY IN ZEBRAFISH (DANIO RERIO)

    OpenAIRE

    Borrelli, Luca

    2015-01-01

    The microbiota is essential in the host's physiology, development, reproduction, immune system, nutrient metabolism, in brain chemistry and behavior. The gut microbiota plays a crucial role in the bidirectional gut–brain axis, a communication that integrates the gut and central nervous system (CNS) activities, and thus, the concept of microbiota–gut–brain axis is emerging where the microbes have considered as signaling components in the gut-brain axis. Animal studies reveals, in particular, t...

  15. Research on pattern recognition for marine steam turbine rotor axis orbit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan; YANG Zhi-da; XIA Hong

    2003-01-01

    The structure,function and recognition method of an axis orbit auto-recognizing system are presented in this paper.In order to make the best use of information of format and dynamic characteristics of marine steam turbine axis orbit,the structure and functions or neural network are applied to this system,which can be used to auto-recognize axis orbit of the system turbine rotor using BP neural network.

  16. Intracerebroventricular leptin injection affects neuroendocrine reproductive axis in ovariectomized rats

    Institute of Scientific and Technical Information of China (English)

    Yuebing Qiao; Huixian Cui

    2008-01-01

    BACKGROUND: Leptin regulates neuroendocrine function of the hypothalamus-pituitary-ovary axis in humans.OBJECTIVE: To verify effects of intracerebroventricular leptin injection on neuroendocrine function of the hypothalamus-pituitary-ovary axis in nvariectomized rats.DESIGN, TIME AND SETTING: A randomized, controlled experiment was performed at the Basic Medical Institute, Chengde Medical College between June and October 2007.MATERIALS: Thirty healthy, female, Wistar rats were included in this study. The following compounds were used: leptin; gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) enzyme-linked immunosorbent assay kits.METHODS: Rats were randomly divided into 3 groups at 1, 2, and 4 hours after injection. Each group was subdivided into control and experimental groups (n = 5 animals per group and time point). All rats were subjected to bilateral ovariectomy and, beginning on day 7 after surgery, animals received daily subcutaneous injections of estradiol benzoate (2 μ g) for 7 consecutive days. The experimental groups were injected with 5 μ L leptin (1 g/L) into the lateral cerebral ventricle, and control groups received an equal volume of physiological saline.MAIN OUTCOME MEASURES: GnRH and LH secretion were examined 1, 2, and 4 hours after injection using GnRH and LH ELISA kits, respectively.RESULTS: In the experimental groups, GnRH secretion significantly increased (P < 0.01), followed by LH secretion (P < 0.01), compared with the control groups. GnRH secretion significantly increased l hour after leptin injection (P < 0.01). The LH increase was less pronounced, but still significant (P < 0.01); however,the most prominent LH increase occurred between 1 and 2 hours. Both GnRH and LH secretion reached peak levels at 2 hours after leptin injection. Thereafter, both GnRH and LH secretion decreased, but still maintained very high levels, compared with the control group (P < 0.01).CONCLUSION: lntracerebroventricular leptin injection

  17. Analisis Semiotika Makna Pesan pada Iklan Axis Versi “Iritologi – Menatap Masa Depan”

    Directory of Open Access Journals (Sweden)

    Puri Sulistiyawati

    2016-02-01

    Full Text Available Abstrak Tujuan dari penelitian ini adalah untuk mengetahui dan menganalisis makna pesan dalam iklan Axis versi “Iritologi – Menatap masa depan” di televisi dengan menggunakan pendekatan semiotika Roland Barthes. Dari analisis yang telah dilakukan berdasarkan makna denotasi, konotasi dan mitos dalam iklan Axis versi “iritologi – Menatap masa depan”, dapat diketahui bahwa iklan Axis memiliki konsep yang sangat sederhana, dengan mengusung tema tentang kebiasaan remaja dalam memanfaatkan media sosial. Dari visual iklan yang ditampilkan menguatkan pesan bahwa produk Axis ini menyasar remaja sebagai target audience, remaja atau pelajar adalah konsumen yang mendambakan produk dengan kalitas baik namun dengan harga yang terjangkau. Meski menyasar remaja, namun dalam target marketnya Axis tetap menyasar semua kalangan. Setting tempat atau latar pada iklan yang ditampilkan pun sebagai representasi bahwa Axis dapat dijangkau oleh semua kalangan ekonomi khususnya masyarakat menengah kebawah. Makna Mitos dalam iklan Axis ini tersirat pada scene tertentu. Secara umum iklan ini menyampaikan bahwa selfie dan media sosial sebagai bagian dari kehidupan masyaraka khususnya generasi muda, sebagai sarana untuk berinteraksi dan menunjukan eksistensinya kepada komunitas. Melalui foto yang diunggah pada media sosial, khalayak merepresentasikan perasaan maupun kegiatan yang sedang di lakukannya. Sehingga hal tersebut memicu kebutuhan akan jaringan komunikasi yang lancar dan ekonomis. Kata Kunci: iklan, axis, semiotika, mitos  Abstract The purpose of this research was to determine and analyze the meaning of message in Axis advertisement version “Iritologi – Menatap masa depan” on television using Roland Barthes semiotic approach. Analysis has been done based on the meaning of denotation, connotation and myth in Axis advertisement version “Iritologi – Menatap masa depan”, it can be seen that Axis advertisement has a simple concept, with a theme of

  18. Optimization of elliptic neutron guides for triple-axis spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Janoschek, M., E-mail: mjanoschek@physics.ucsd.ed [II. Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln (Germany); Physik Department E21, Technische Universitaet Muenchen, D-85748 Garching (Germany); Boeni, P., E-mail: peter.boeni@frm2.tum.d [Physik Department E21, Technische Universitaet Muenchen, D-85748 Garching (Germany); Braden, M., E-mail: braden@ph2.uni-koeln.d [II. Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln (Germany)

    2010-01-21

    In the last decade the performance of neutron guides for the transport of neutrons has been significantly increased. The most recent developments have shown that elliptic guide systems can be used to focus neutron beams while simultaneously reducing the number of neutron reflections, hence, leading to considerable gains in neutron flux. We have carried out Monte-Carlo simulations for a new triple-axis spectrometer that will be built at the end position of the conventional cold guide NL-1 in the neutron guide hall of the research reactor FRM-II in Munich, Germany. Our results demonstrate that an elliptic guide section at the end of a conventional guide can be used to at least maintain the total neutron flux onto the sample, while significantly improving the energy resolution of the spectrometer. The simulation further allows detailed insight how the defining parameters of an elliptic guide have to be chosen to obtain optimum results. Finally, we show that the elliptic guide limits losses in the neutron flux that generally arise at the gaps, where the monochromator system of the upstream instrument is situated.

  19. Magnetic resonance imaging of hypothalamus hypophysis axis lesions

    International Nuclear Information System (INIS)

    Magnetic resonance imaging (MRI) using a 0.5T superconductive machine was performed to the thirty three cases with a variety of the sellar and parasellar tumors and with dysfunction of the hypothalamus-hypophysis axis. Posterior pituitary bright spot (PBS) on T1 weighted image was evaluated with the pituitary hormonal function. These cases were 12 cases of post-treated tumors including pituitary adenoma (9 patients), suprasellar germinoma (2 patients) and craniopharyngioma (one patient), and non-tumorous conditions including 15 cases of central diabetes insipidus (DI), Syndrome of inappropriate secretion of ADH (SIADH) (one patient), Sheehan's syndrome (3 patients) and anorexia nervosa (2 patients). Pituitary bright spot was not seen in all 19 cases with overt DI. On the other hand, PBS was not seen in 9 cases without overt DI. Three cases of these 9 cases showing Sheehan's syndrome with insufficient antidiuretic hormone (ADH) secretion was considered as the state of subclinical DI. Posterior bright spot was not seen in all 13 cases of empty sella including partial empty sella. The results suggested that disappearance of PBS represents abnormality or loss of posterior pituitary function and also it was considered to be closely related to the empty sella. (author)

  20. GAMMA-RAY BURSTS ARE OBSERVED OFF-AXIS

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Geoffrey; Van Eerten, Hendrik; MacFadyen, Andrew [Center for Cosmology and Particle Physics, Physics Department, New York University, New York, NY 10003 (United States); Zhang, Bin-Bin, E-mail: gsr257@nyu.edu [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2015-01-20

    We constrain the jet opening angle and, for the first time, the off-axis observer angle for gamma-ray bursts in the Swift-XRT catalog by using the ScaleFit package to fit afterglow light curves directly to hydrodynamic simulations. The ScaleFit model uses scaling relations in the hydrodynamic and radiation equations to compute synthetic light curves directly from a set of high-resolution two-dimensional relativistic blast wave simulations. The data sample consists of all Swift-XRT afterglows from 2005 to 2012 with sufficient coverage and a known redshift, 226 bursts in total. We find that the jet half-opening angle varies widely but is commonly less than 0.1 rad. The distribution of the electron spectral index is also broad, with a median at 2.30. We find the observer angle to have a median value of 0.57 of the jet opening angle over our sample, which has profound consequences for the predicted rate of observed jet breaks and affects the beaming-corrected total energies of gamma-ray bursts.

  1. Propagation of angular errors in two-axis rotation systems

    Science.gov (United States)

    Torrington, Geoffrey K.

    2003-10-01

    Two-Axis Rotation Systems, or "goniometers," are used in diverse applications including telescope pointing, automotive headlamp testing, and display testing. There are three basic configurations in which a goniometer can be built depending on the orientation and order of the stages. Each configuration has a governing set of equations which convert motion between the system "native" coordinates to other base systems, such as direction cosines, optical field angles, or spherical-polar coordinates. In their simplest form, these equations neglect errors present in real systems. In this paper, a statistical treatment of error source propagation is developed which uses only tolerance data, such as can be obtained from the system mechanical drawings prior to fabrication. It is shown that certain error sources are fully correctable, partially correctable, or uncorrectable, depending upon the goniometer configuration and zeroing technique. The system error budget can be described by a root-sum-of-squares technique with weighting factors describing the sensitivity of each error source. This paper tabulates weighting factors at 67% (k=1) and 95% (k=2) confidence for various levels of maximum travel for each goniometer configuration. As a practical example, this paper works through an error budget used for the procurement of a system at Sandia National Laboratories.

  2. A broadband two axis flux-gate magnetometer

    Directory of Open Access Journals (Sweden)

    P. Palangio

    1998-06-01

    Full Text Available A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

  3. Hydroelastic dynamic characteristics of a slender axis-symmetric body

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The slender axis-symmetric submarine body moving in the vertical plane is the object of our investigation.A coupling model is developed where displacements of a solid body as a Euler beam(consisting of rigid motions and elastic deformations) and fluid pressures are employed as basic independent variables,including the interaction between hydrodynamic forces and structure dynamic forces.Firstly the hydrodynamic forces,depending on and conversely influencing body motions,are taken into account as the governing equations.The expressions of fluid pressure are derived based on the potential theory.The characteristics of fluid pressure,including its components,distribution and effect on structure dynamics,are analyzed.Then the coupling model is solved numerically by means of a finite element method(FEM).This avoids the complicacy,combining CFD(fluid) and FEM(structure),of direct numerical simulation,and allows the body with a non-strict ideal shape so as to be more suitable for practical engineering.An illustrative example is given in which the hydroelastic dynamic characteristics,natural frequencies and modes of a submarine body are analyzed and compared with experimental results.Satisfactory agreement is observed and the model presented in this paper is shown to be valid.

  4. Hydroelastic dynamic characteristics of a slender axis-symmetric body

    Science.gov (United States)

    Chen, Weimin; Li, Min; Zheng, Zhongqin; Zhang, Liwu

    2010-07-01

    The slender axis-symmetric submarine body moving in the vertical plane is the object of our investigation. A coupling model is developed where displacements of a solid body as a Euler beam (consisting of rigid motions and elastic deformations) and fluid pressures are employed as basic independent variables, including the interaction between hydrodynamic forces and structure dynamic forces. Firstly the hydrodynamic forces, depending on and conversely influencing body motions, are taken into account as the governing equations. The expressions of fluid pressure are derived based on the potential theory. The characteristics of fluid pressure, including its components, distribution and effect on structure dynamics, are analyzed. Then the coupling model is solved numerically by means of a finite element method (FEM). This avoids the complicacy, combining CFD (fluid) and FEM (structure), of direct numerical simulation, and allows the body with a non-strict ideal shape so as to be more suitable for practical engineering. An illustrative example is given in which the hydroelastic dynamic characteristics, natural frequencies and modes of a submarine body are analyzed and compared with experimental results. Satisfactory agreement is observed and the model presented in this paper is shown to be valid.

  5. MRI of the hypothalamic-pituitary axis in children

    Energy Technology Data Exchange (ETDEWEB)

    Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece); Kiortsis, Dimitrios Nikiforos [University of Ioannina, Department of Physiology, Medical School, Ioannina (Greece)

    2005-11-01

    In childhood, the MR characteristics of the normal pituitary gland are well established. During the first 2 months of life the adenohypophysis demonstrates high signal. Pituitary gland height (PGH) decreases during the 1st year of life and then increases, reaching a plateau after puberty. The magnetization transfer ratio (MTR) increases in both sexes up to the age of 20 years. On dynamic contrast-enhanced studies, the posterior pituitary lobe enhances simultaneously with the straight sinus, and the adenohypophysis later, but within 30 s. In genetically determined dysfunctional states, the adenohypophysis may be normal, hypoplastic, or enlarged. Pituitary enlargement, observed in Prop 1 gene mutations, is characterized by a mass interposed between the anterior and posterior lobes. An ectopic posterior lobe (EPP), associated with a hypoplastic or absent pituitary stalk, may be observed in patients with hypopituitarism. Tumors of the hypothalamic-pituitary (HP) axis may be the origin of adenohypophyseal deficiencies. A small hypointense adenohypophysis is found in iron overload states and is often associated with hypogonadotrophic hypogonadism. Absence of the posterior lobe bright signal, with or without a thick pituitary stalk or a mass at any site from the median eminence to the posterior pituitary lobe, may be found in diabetes insipidus. Hydrocephalus, suprasellar arachnoid cysts, hypothalamic hamartomas and craniopharyngiomas may result in central precocious puberty (CPP). Increased PGH in girls with idiopathic CPP is useful for its differential diagnosis from premature thelarche (PT). Pituitary adenomas, observed mainly in adolescents, present the same MR characteristics as those in adults. (orig.)

  6. Optical axis jitter rejection for double overlapped adaptive optics systems

    Science.gov (United States)

    Luo, Qi; Luo, Xi; Li, Xinyang

    2016-04-01

    Optical axis jitters, or vibrations, which arise from wind shaking and structural oscillations of optical platforms, etc., cause a deleterious impact on the performance of adaptive optics systems. When conventional integrators are utilized to reject such high frequency and narrow-band disturbance, the benefits are quite small despite their acceptable capabilities to reject atmospheric turbulence. In our case, two suits of complete adaptive optics systems called double overlapped adaptive optics systems (DOAOS) are used to counteract both optical jitters and atmospheric turbulence. A novel algorithm aiming to remove vibrations is proposed by resorting to combine the Smith predictor and notch filer. With the help of loop shaping method, the algorithm will lead to an effective and stable controller, which makes the characteristics of error transfer function close to notch filters. On the basis of the spectral analysis of observed data, the peak frequency and bandwidth of vibrations can be identified in advance. Afterwards, the number of notch filters and their parameters will be determined using coordination descending method. The relationship between controller parameters and filtering features is discussed, and the robustness of the controller against varying parameters of the control object is investigated. Preliminary experiments are carried out to validate the proposed algorithms. The overall control performance of DOAOS is simulated. Results show that time delays are a limit of the performance, but the algorithm can be successfully implemented on our systems, which indicate that it has a great potential to reject jitters.

  7. Guanylyl cyclase C signaling axis and colon cancer prevention

    Science.gov (United States)

    Pattison, Amanda M; Merlino, Dante J; Blomain, Erik S; Waldman, Scott A

    2016-01-01

    Colorectal cancer (CRC) is a major cause of cancer-related mortality and morbidity worldwide. While improved treatments have enhanced overall patient outcome, disease burden encompassing quality of life, cost of care, and patient survival has seen little benefit. Consequently, additional advances in CRC treatments remain important, with an emphasis on preventative measures. Guanylyl cyclase C (GUCY2C), a transmembrane receptor expressed on intestinal epithelial cells, plays an important role in orchestrating intestinal homeostatic mechanisms. These effects are mediated by the endogenous hormones guanylin (GUCA2A) and uroguanylin (GUCA2B), which bind and activate GUCY2C to regulate proliferation, metabolism and barrier function in intestine. Recent studies have demonstrated a link between GUCY2C silencing and intestinal dysfunction, including tumorigenesis. Indeed, GUCY2C silencing by the near universal loss of its paracrine hormone ligands increases colon cancer susceptibility in animals and humans. GUCY2C’s role as a tumor suppressor has opened the door to a new paradigm for CRC prevention by hormone replacement therapy using synthetic hormone analogs, such as the FDA-approved oral GUCY2C ligand linaclotide (Linzess™). Here we review the known contributions of the GUCY2C signaling axis to CRC, and relate them to a novel clinical strategy targeting tumor chemoprevention. PMID:27688649

  8. Morping blade design for vertical axis wind turbines

    Science.gov (United States)

    Macphee, David; Beyene, Asfaw

    2015-11-01

    Wind turbines operate at peak efficiency at a certain set of operational conditions. Away from these conditions, conversion efficiency drops significantly, requiring pitch and yaw control schemes to mitigate these losses. These efforts are an example of geometric variability, allowing for increased power production but with an unfortunate increase in investment cost to the energy conversion system. In Vertical-Axis Wind Turbines (VAWTs), the concept of pitch control is especially complicated due to a dependence of attack angle on armature azimuth. As a result, VAWT pitch control schemes, both active and passive, are as of yet unfeasible. This study investigates a low-cost, passive pitch control system, in which VAWT blades are constructed of a flexible material, allowing for continuous shape-morphing in response to local aerodynamic loading. This design is analyzed computationally using a finite-volume fluid-structure interaction routine and compared to a geometrically identical rigid rotor. The results indicate that the flexible blade increases conversion efficiency by reducing the severity of vortex shedding, allowing for greater average torque over a complete revolution.

  9. Design of h-Darrieus vertical axis wind turbine

    Science.gov (United States)

    Parra, Teresa; Vega, Carmen; Gallegos, A.; Uzarraga, N. C.; Castro, F.

    2015-05-01

    Numerical simulation is used to predict the performance of a Vertical Axis Wind Turbine (VAWT) H-Darrieus. The rotor consists of three straight blades with shape of aerofoil of the NACA family attached to a rotating vertical shaft. The influence of the solidity is tested to get design tendencies. The mesh has two fluid volumes: one sliding mesh for the rotor where the rotation velocity is established while the other is the environment of the rotor. Bearing in mind the overall flow is characterized by important secondary flows, the turbulence model selected was realizable k-epsilon with non-equilibrium wall functions. Conservation equations were solved with a Third-Order Muscl scheme using SIMPLE to couple pressure and velocity. During VAWT operation, the performance depends mainly on the relative motion of the rotating blade and has a fundamental period which depends both on the rate of rotation and the number of blades. The transient study is necessary to characterise the hysteresis phenomenon. Hence, more than six revolutions get the periodic behaviour. Instantaneous flows provide insight about wake structure interaction. Time averaged parameters let obtain the characteristic curves of power coefficient.

  10. 3D CFD Analysis of a Vertical Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Andrea Alaimo

    2015-04-01

    Full Text Available To analyze the complex and unsteady aerodynamic flow associated with wind turbine functioning, computational fluid dynamics (CFD is an attractive and powerful method. In this work, the influence of different numerical aspects on the accuracy of simulating a rotating wind turbine is studied. In particular, the effects of mesh size and structure, time step and rotational velocity have been taken into account for simulation of different wind turbine geometries. The applicative goal of this study is the comparison of the performance between a straight blade vertical axis wind turbine and a helical blade one. Analyses are carried out through the use of computational fluid dynamic ANSYS® Fluent® software, solving the Reynolds averaged Navier–Stokes (RANS equations. At first, two-dimensional simulations are used in a preliminary setup of the numerical procedure and to compute approximated performance parameters, namely the torque, power, lift and drag coefficients. Then, three-dimensional simulations are carried out with the aim of an accurate determination of the differences in the complex aerodynamic flow associated with the straight and the helical blade turbines. Static and dynamic results are then reported for different values of rotational speed.

  11. Investigation of implementation of stators on vertical axis wind turbines

    Science.gov (United States)

    Alexander, Aaron; Santhanakrishnan, Arvind

    2014-11-01

    Vertical Axis Wind Turbines (VAWT) have historically suffered from an inability to self-start and, especially on Savonius rotors, low efficiencies due to drag on the returning blade. A few VAWT studies have examined the use of stators to direct the flow onto the power producing side of the rotor thus preventing drag on the returning side, yet all of the designs studied allow the air to exit on the downstream side of the entering flow. This study investigates an alternative stator design for extracting more wind energy by trapping the incoming flow into a rising vortex within the stator enclosure. The flow is then allowed to exit above the stator. The current study compared the performance of a generic Savonius rotor in a 7 m/s free stream flow with the same rotor in two different stator designs. The first stator design allows the flow to escape in the downstream direction. The second stator design utilizes the same stator shape, but forces the air to remain trapped until it can exit above the stators. The initial evaluation of the results was conducted using Computational Fluid Dynamics (CFD) package Star-CCM + set up with an unsteady k- ɛ model at a Reynolds number of about 1,400,000. Experimental comparisons with scale models will be presented.

  12. Multi axis differential optical absorption spectroscopy (MAX-DOAS

    Directory of Open Access Journals (Sweden)

    G. Hönninger

    2004-01-01

    Full Text Available Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS in the atmosphere is a novel measurement technique that represents a significant advance on the well-established zenith scattered sunlight DOAS instruments which are mainly sensitive to stratospheric absorbers. MAX-DOAS utilizes scattered sunlight received from multiple viewing directions. The spatial distribution of various trace gases close to the instrument can be derived by combining several viewing directions. Ground based MAX-DOAS is highly sensitive to absorbers in the lowest few kilometres of the atmosphere and vertical profile information can be retrieved by combining the measurements with Radiative Transfer Model (RTM calculations. The potential of the technique for a wide variety of studies of tropospheric trace species and its (few limitations are discussed. A Monte Carlo RTM is applied to calculate Airmass Factors (AMF for the various viewing geometries of MAX-DOAS. Airmass Factors can be used to quantify the light path length within the absorber layers. The airmass factor dependencies on the viewing direction and the influence of several parameters (trace gas profile, ground albedo, aerosol profile and type, solar zenith and azimuth angles are investigated. In addition we give a brief description of the instrumental MAX-DOAS systems realised and deployed so far. The results of the RTM studies are compared to several examples of recent MAX-DOAS field experiments and an outlook for future possible applications is given.

  13. Guanylyl cyclase C signaling axis and colon cancer prevention

    Science.gov (United States)

    Pattison, Amanda M; Merlino, Dante J; Blomain, Erik S; Waldman, Scott A

    2016-01-01

    Colorectal cancer (CRC) is a major cause of cancer-related mortality and morbidity worldwide. While improved treatments have enhanced overall patient outcome, disease burden encompassing quality of life, cost of care, and patient survival has seen little benefit. Consequently, additional advances in CRC treatments remain important, with an emphasis on preventative measures. Guanylyl cyclase C (GUCY2C), a transmembrane receptor expressed on intestinal epithelial cells, plays an important role in orchestrating intestinal homeostatic mechanisms. These effects are mediated by the endogenous hormones guanylin (GUCA2A) and uroguanylin (GUCA2B), which bind and activate GUCY2C to regulate proliferation, metabolism and barrier function in intestine. Recent studies have demonstrated a link between GUCY2C silencing and intestinal dysfunction, including tumorigenesis. Indeed, GUCY2C silencing by the near universal loss of its paracrine hormone ligands increases colon cancer susceptibility in animals and humans. GUCY2C’s role as a tumor suppressor has opened the door to a new paradigm for CRC prevention by hormone replacement therapy using synthetic hormone analogs, such as the FDA-approved oral GUCY2C ligand linaclotide (Linzess™). Here we review the known contributions of the GUCY2C signaling axis to CRC, and relate them to a novel clinical strategy targeting tumor chemoprevention.

  14. Numerical study on small scale vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Parra-Santos Teresa

    2016-01-01

    Full Text Available The performance of a Vertical Axis Wind Turbine (VAWT is numerically analyzed. The set-up is Hdarrieus with three straight blades airfoils NACA attached to a rotating vertical shaft. The wind turbine has solidity equals to the unity operating with wind velocity of 7 m/s. Influence of pitch angle is tested to get design tendencies. 2D, transient, Navier Stokes equations are solved using the code Ansys-Fluent. Conservation equations were solved with a Third-Order MUSCL scheme using SIMPLE to couple pressure and velocity. More than six revolutions must be simulated to get the periodic behavior. Two models of turbulence have been contrasted Realizable k-epsilon and Transition SST concluding the last one show more realistic flow features. Pitch angles of 0º, -6º and -10º have been tested with Tip Speed Ratios ranging from 0.7 and 1.6. The no null pitch angles improve the performance of the wind turbine. Instantaneous and averaged power coefficients as well as detailed flow field around the airfoils are showed.

  15. Design of h-Darrieus vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Parra Teresa

    2015-01-01

    Full Text Available Numerical simulation is used to predict the performance of a Vertical Axis Wind Turbine (VAWT H-Darrieus. The rotor consists of three straight blades with shape of aerofoil of the NACA family attached to a rotating vertical shaft. The influence of the solidity is tested to get design tendencies. The mesh has two fluid volumes: one sliding mesh for the rotor where the rotation velocity is established while the other is the environment of the rotor. Bearing in mind the overall flow is characterized by important secondary flows, the turbulence model selected was realizable k-epsilon with non-equilibrium wall functions. Conservation equations were solved with a Third-Order Muscl scheme using SIMPLE to couple pressure and velocity. During VAWT operation, the performance depends mainly on the relative motion of the rotating blade and has a fundamental period which depends both on the rate of rotation and the number of blades. The transient study is necessary to characterise the hysteresis phenomenon. Hence, more than six revolutions get the periodic behaviour. Instantaneous flows provide insight about wake structure interaction. Time averaged parameters let obtain the characteristic curves of power coefficient.

  16. Off-axis electron holography of ferromagnetic multilayer nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Akhtari-Zavareh, Azadeh; Kavanagh, K. L. [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A1S6 (Canada); Carignan, L. P. [Apollo Microwaves, 1650 Trans-Canada Highway, Dorval, Quebec H9P 1H7 (Canada); Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Quebec, H3C 3A7 Canada (Canada); Department of Electrical Engineering, École Polytechnique de Montréal, Montréal, Quebec, H3C 3A7 Canada (Canada); Yelon, A.; Ménard, D. [Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Quebec, H3C 3A7 Canada (Canada); Kasama, T. [Center for Electron Nanoscopy, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Herring, R. [Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Dunin-Borkowski, R. E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Institute for Microstructure Research, D-52425 Jülich (Germany); McCartney, M. R. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)

    2014-07-14

    We have used electron holography to investigate the local magnetic behavior of isolated ferromagnetic nanowires (NWs) in their remanent states. The NWs consisted of periodic magnetic layers of soft, high-saturation magnetization CoFeB alloys, and non-magnetic layers of Cu. All NWs were fabricated by pulsed-potential electrodeposition in nanoporous alumina membranes. The NW composition and layer thicknesses were measured using scanning transmission electron microscopy and energy dispersive spectroscopy. The magnetization of individual NWs depended upon the thicknesses of the layers and the direction of an external magnetic field, which had been applied in situ. When the CoFeB was thicker than the diameter (50 nm), magnetization was axial for all external field directions, while thinner layers could be randomized via a perpendicular field. In some cases, magnetization inside the wire was detected at an angle with respect to the axis of the wires. In thinner Cu/CoFeB (<10 nm each) multilayer, magnetic field vortices were detected, associated with opposing magnetization in neighbouring layers. The measured crystallinity, compositions, and layer thicknesses of individual NWs were found to be significantly different from those predicted from calibration growths based on uniform composition NWs. In particular, a significant fraction of Cu (up to 50 at. %) was present in the CoFeB layers such that the measured magnetic induction was lower than expected. These results will be used to better understand previously measured effective anisotropy fields of similar NW arrays.

  17. The Parameters Affect on Power Coefficient Vertical Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Ahmed Y. Qasim

    2012-04-01

    Full Text Available ABSTRACT: This study describes the design of a special type of vertical axis rotor wind turbine with moveable vertically positioned vanes. The novel design increases the torque in the left side of the wind turbine by increasing the drag coefficient. It also reduces the negative torque of the frame which rotates contrary to the wind in the other side. Two different types of models, having different vane shapes (flat vane and cavity shaped vane, were fabricated. Each type consisted of two models with varying number of frames (three and four frames. The models were tested in a wind tunnel with variable wind speed in order to understand the effect of shape, weight, and number of frames on the power coefficient of the wind turbine. ABSTRAK: Di dalam kajian ini, rotor turbin angin berpaksi vertikel sebagai rangka khusus telah direkabentuk dengan lokasi vertikel mudahalih oleh bilah kipas. Rekabentuk ini meningkatkan tork di bahagian kiri turbin angin dengan meningkatkan pekali seretan dan mengurangkan tork negatif rangka yang berputar berlawanan dengan angin pada bahagian lain. Dua jenis model berbentuk berlainan telah difabrikasi (bilah kipas rata dan bilah kipas berbentuk kaviti, dengan setiap jenis mempunyai dua model dengan bilangan rangka yang berlainan (berangka tiga dan berangka empat. Model-model telah diuji di dalam terowong angin dengan kelajuan angin yang berbeza bagi mendapatkan kesan rekabentuk, berat dan bilangan rangka ke atas pekali kuasa.KEYWORDS: design; wind turbine; drag coefficient; vane

  18. On the theory of the horizontal-axis wind turbine

    Science.gov (United States)

    de Vries, O.

    The fluid mechanical theory of horizontal axis wind turbines (HAWT) in homogeneous, steady flows is presented. HAWT aerodynamic performance is governed by rotor torque and drag, the angular velocity, and power output, with governing equations for momentum, mass, and energy. The lift force and profile drag acting on the airfoil blades depend on the flow velocity, the chord length, the angle of attack, and the lift and drag coefficients. Single streamtube and multiple-stream tube and angular momentum analyses are employed to quantify the maximum wind turbine performance. Optimization studies for HAWT blades have indicated that a considerable amount of blade twist and taper enhances HAWT performance. Blade-element and vortex theory combined with panel methods are used to study optimum blade shapes. Techniques for assuring that wind tunnel studies of scale models are valid for full scale machines are defined. Sample runs have shown the accuracy of the blade element theory and the inaccuracies of two-dimensional analyses when stall is reached. The acquisition of more aerodynamic data on HAWT performance is indicated.

  19. Aeroelastic stability and response of horizontal axis wind turbine blades

    Science.gov (United States)

    Kottapalli, S. B. R.; Friedmann, P. P.; Rosen, A.

    1979-01-01

    Coupled flap-lag-torsion equations of motion of an isolated horizontal axis wind turbine (HAWT) blade have been formulated. The analysis neglects blade-tower coupling. The final nonlinear equations have periodic coefficients. A new and convenient method of generating an appropriate time-dependent equilibrium position, required for the stability analysis, has been implemented and found to be computationally efficient. Steady-state response and stability boundaries for an existing (typical) HAWT blade are presented. Such stability boundaries have never been published in the literature. The results show that the isolated blade under study is basically stable. The tower shadow (wake) has a considerable effect on the out-of-plane response but leaves blade stability unchanged. Nonlinear terms can significantly affect linearized stability boundaries; however, they have a negligible effect on response, thus implying that a time-dependent equilibrium position (or steady-state response), based completely on the linear system, is appropriate for the type of HAWT blades under study.

  20. Physiological focus on the erythropoietin-hepcidin-ferroportin axis.

    Science.gov (United States)

    D'Anna, María Cecilia; Roque, Marta Elena

    2013-05-01

    To analyze the interconnection between erythropoiesis and iron metabolism, one of the issues raised in this study was to know iron bioavailability under physiopathological conditions. Our aim was to understand the functional axis response composed of erythropoietin (Epo)-hepcidin-ferroportin (FPN), when 2 dysfunctional states coexist, using an animal model of iron overload followed by hypoxia. FPN and prohepcidin were assessed by immunohistochemistry using rabbit anti-mouse FPN polyclonal and prohepcidin monoclonal antibodies. Goat-labeled polymer - horseradish peroxidase anti-rabbit EnVision + System (DAB) was used as the secondary antibody. Epo levels were measured by ELISA. Tissue iron was studied by Prussian blue iron staining. Erythropoietic response was assessed using conventional hematological tests. Iron overload increased prohepcidin that remained high in hypoxia, coexisting with high levels of Epo in hypoxia, with or without iron overload. In hypoxia, FPN was clearly evident in reticuloendothelial macrophages, more than in hypoxia with iron overload. Interestingly, duodenal FPN was clearly identified on the basolateral membrane in hypoxia, with or without iron overload. Our data indicate that 2 signals could induce the cell-specific response as follows: (i) iron signal, induced prohepcidin, which reduced reticuloendothelial FPN and reduced iron availability; and (ii) hypoxia signal, stimulated Epo, which affected iron absorption by stabilizing duodenal FPN and allowed iron supply to erythropoiesis independently of store size. PMID:23656253

  1. Equine hyperinsulinemia: investigation of the enteroinsular axis during insulin dysregulation.

    Science.gov (United States)

    de Laat, M A; McGree, J M; Sillence, M N

    2016-01-01

    Compared with some other species, insulin dysregulation in equids is poorly understood. However, hyperinsulinemia causes laminitis, a significant and often lethal disease affecting the pedal bone/hoof wall attachment site. Until recently, hyperinsulinemia has been considered a counterregulatory response to insulin resistance (IR), but there is growing evidence to support a gastrointestinal etiology. Incretin hormones released from the proximal intestine, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, augment insulin secretion in several species but require investigation in horses. This study investigated peripheral and gut-derived factors impacting insulin secretion by comparing the response to intravenous (iv) and oral d-glucose. Oral and iv tests were performed in 22 ponies previously shown to be insulin dysregulated, of which only 15 were classified as IR (iv test). In a more detailed study, nine different ponies received four treatments: d-glucose orally, d-glucose iv, oats, and commercial grain mix. Insulin, glucose, and incretin concentrations were measured before and after each treatment. All nine ponies showed similar iv responses, but five were markedly hyperresponsive to oral d-glucose and four were not. Insulin responsiveness to oral d-glucose was strongly associated with blood glucose concentrations and oral glucose bioavailability, presumably driven by glucose absorption/distribution, as there was no difference in glucose clearance rates. Insulin was also positively associated with the active amide of GLP-1 following d-glucose and grain. This study has confirmed a functional enteroinsular axis in ponies that likely contributes to insulin dysregulation that may predispose them to laminitis. Moreover, iv tests for IR are not reliable predictors of the oral response to dietary nonstructural carbohydrate. PMID:26530154

  2. Effects of Carbenoxolone on the Canine Pituitary-Adrenal Axis.

    Directory of Open Access Journals (Sweden)

    Takahiro Teshima

    Full Text Available Cushing's disease caused by pituitary corticotroph adenoma is a common endocrine disease in dogs. A characteristic biochemical feature of corticotroph adenomas is their relative resistance to suppressive negative feedback by glucocorticoids. The abnormal expression of 11beta-hydroxysteroid dehydrogenase (11HSD, which is a cortisol metabolic enzyme, is found in human and murine corticotroph adenomas. Our recent studies demonstrated that canine corticotroph adenomas also have abnormal expression of 11HSD. 11HSD has two isoforms in dogs, 11HSD type1 (HSD11B1, which converts cortisone into active cortisol, and 11HSD type2 (HSD11B2, which converts cortisol into inactive cortisone. It has been suggested that glucocorticoid resistance in corticotroph tumors is related to the overexpression of HSD11B2. Therefore it was our aim to investigate the effects of carbenoxolone (CBX, an 11HSD inhibitor, on the healthy dog's pituitary-adrenal axis. Dogs were administered 50 mg/kg of CBX twice each day for 15 days. During CBX administration, no adverse effects were observed in any dogs. The plasma adrenocorticotropic hormone (ACTH, and serum cortisol and cortisone concentrations were significantly lower at day 7 and 15 following corticotropin releasing hormone stimulation. After completion of CBX administration, the HSD11B1 mRNA expression was higher, and HSD11B2 mRNA expression was significantly lower in the pituitaries. Moreover, proopiomelanocortin mRNA expression was lower, and the ratio of ACTH-positive cells in the anterior pituitary was also significantly lower after CBX treatment. In adrenal glands treated with CBX, HSD11B1 and HSD11B2 mRNA expression were both lower compared to normal canine adrenal glands. The results of this study suggested that CBX inhibits ACTH secretion from pituitary due to altered 11HSD expressions, and is potentially useful for the treatment of canine Cushing's disease.

  3. Large Eddy Simulation of Vertical Axis Wind Turbine Wakes

    Directory of Open Access Journals (Sweden)

    Sina Shamsoddin

    2014-02-01

    Full Text Available In this study, large eddy simulation (LES is combined with a turbine model to investigate the wake behind a vertical-axis wind turbine (VAWT in a three-dimensional turbulent flow. Two methods are used to model the subgrid-scale (SGS stresses: (a the Smagorinsky model; and (b the modulated gradient model. To parameterize the effects of the VAWT on the flow, two VAWT models are developed: (a the actuator swept-surface model (ASSM, in which the time-averaged turbine-induced forces are distributed on a surface swept by the turbine blades, i.e., the actuator swept surface; and (b the actuator line model (ALM, in which the instantaneous blade forces are only spatially distributed on lines representing the blades, i.e., the actuator lines. This is the first time that LES has been applied and validated for the simulation of VAWT wakes by using either the ASSM or the ALM techniques. In both models, blade-element theory is used to calculate the lift and drag forces on the blades. The results are compared with flow measurements in the wake of a model straight-bladed VAWT, carried out in the Institute de Méchanique et Statistique de la Turbulence (IMST water channel. Different combinations of SGS models with VAWT models are studied, and a fairly good overall agreement between simulation results and measurement data is observed. In general, the ALM is found to better capture the unsteady-periodic nature of the wake and shows a better agreement with the experimental data compared with the ASSM. The modulated gradient model is also found to be a more reliable SGS stress modeling technique, compared with the Smagorinsky model, and it yields reasonable predictions of the mean flow and turbulence characteristics of a VAWT wake using its theoretically-determined model coefficient.

  4. Endocrine disruptors and estrogenic effects on male reproductive axis

    Institute of Scientific and Technical Information of China (English)

    Suresh C. Sikka; Run Wang

    2008-01-01

    Endocrine disruptors (e.g., polychlorinated biphenyls [PCBs], dichlorodiphenyl-trichloroethane [DDT], dioxin,and some pesticides) are estrogen-like and anti-androgenic chemicals in the environment. They mimic natural hormones,inhibit the action of hormones, or alter the normal regulatory function of the endocrine system and have potential hazardous effects on male reproductive axis causing infertility. Although testicular and prostate cancers, abnormal sexual development, undescended testis, chronic inflammation, Sertoli-cell-only pattern, hypospadias, altered pituitary and thyroid gland functions are also observed, the available data are insufficient to deduce worldwide conclusions.The development of intra-cytoplasmic sperm injection (ICSI) is beyond doubt the most important recent breakthrough in the treatment of male infertility, but it does not necessarily treat the cause and may inadvertently pass on adverse genetic consequences. Many well-controlled clinical studies and basic scientific discoveries in the physiology,biochemistry, and molecular and cellular biology of the male reproductive system have helped in the identification of greater numbers of men with male factor problems. Newer tools for the detection of Y-chromosome deletions have further strengthened the hypothesis that the decline in male reproductive health and fertility may be related to the presence of certain toxic chemicals in the environment. Thus the etiology, diagnosis, and treatment of male factor infertility remain a real challenge. Clinicians should always attempt to identify the etiology of a possible testicular toxicity, assess the degree of risk to the patient being evaluated for infertility, and initiate a plan to control and prevent exposure to others once an association between occupation/toxicant and infertility has been established.

  5. 60 YEARS OF NEUROENDOCRINOLOGY: The hypothalamo-prolactin axis.

    Science.gov (United States)

    Grattan, David R

    2015-08-01

    The hypothalamic control of prolactin secretion is different from other anterior pituitary hormones, in that it is predominantly inhibitory, by means of dopamine from the tuberoinfundibular dopamine neurons. In addition, prolactin does not have an endocrine target tissue, and therefore lacks the classical feedback pathway to regulate its secretion. Instead, it is regulated by short loop feedback, whereby prolactin itself acts in the brain to stimulate production of dopamine and thereby inhibit its own secretion. Finally, despite its relatively simple name, prolactin has a broad range of functions in the body, in addition to its defining role in promoting lactation. As such, the hypothalamo-prolactin axis has many characteristics that are quite distinct from other hypothalamo-pituitary systems. This review will provide a brief overview of our current understanding of the neuroendocrine control of prolactin secretion, in particular focusing on the plasticity evident in this system, which keeps prolactin secretion at low levels most of the time, but enables extended periods of hyperprolactinemia when necessary for lactation. Key prolactin functions beyond milk production will be discussed, particularly focusing on the role of prolactin in inducing adaptive responses in multiple different systems to facilitate lactation, and the consequences if prolactin action is impaired. A feature of this pleiotropic activity is that functions that may be adaptive in the lactating state might be maladaptive if prolactin levels are elevated inappropriately. Overall, my goal is to give a flavour of both the history and current state of the field of prolactin neuroendocrinology, and identify some exciting new areas of research development.

  6. Characterization of a multi-axis ion chamber array

    International Nuclear Information System (INIS)

    Purpose: The aim of this work was to characterize a multi-axis ion chamber array (IC PROFILER; Sun Nuclear Corporation, Melbourne, FL USA) that has the potential to simplify the acquisition of LINAC beam data. Methods: The IC PROFILER (or panel) measurement response was characterized with respect to radiation beam properties, including dose, dose per pulse, pulse rate frequency (PRF), and energy. Panel properties were also studied, including detector-calibration stability, power-on time, backscatter dependence, and the panel's agreement with water tank measurements [profiles, fractional depth dose (FDD), and output factors]. Results: The panel's relative deviation was typically within (±) 1% of an independent (or nominal) response for all properties that were tested. Notable results were (a) a detectable relative field shape change of ∼1% with linear accelerator PRF changes; (b) a large range in backscatter thickness had a minimal effect on the measured dose distribution (typically less than 1%); (c) the error spread in profile comparison between the panel and scanning water tank (Blue Phantom, CC13; IBA Schwarzenbruck, DE) was approximately (±) 0.75%. Conclusions: The ability of the panel to accurately reproduce water tank profiles, FDDs, and output factors is an indication of its abilities as a dosimetry system. The benefits of using the panel versus a scanning water tank are less setup time and less error susceptibility. The same measurements (including device setup and breakdown) for both systems took 180 min with the water tank versus 30 min with the panel. The time-savings increase as the measurement load is increased.

  7. Equine hyperinsulinemia: investigation of the enteroinsular axis during insulin dysregulation.

    Science.gov (United States)

    de Laat, M A; McGree, J M; Sillence, M N

    2016-01-01

    Compared with some other species, insulin dysregulation in equids is poorly understood. However, hyperinsulinemia causes laminitis, a significant and often lethal disease affecting the pedal bone/hoof wall attachment site. Until recently, hyperinsulinemia has been considered a counterregulatory response to insulin resistance (IR), but there is growing evidence to support a gastrointestinal etiology. Incretin hormones released from the proximal intestine, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, augment insulin secretion in several species but require investigation in horses. This study investigated peripheral and gut-derived factors impacting insulin secretion by comparing the response to intravenous (iv) and oral d-glucose. Oral and iv tests were performed in 22 ponies previously shown to be insulin dysregulated, of which only 15 were classified as IR (iv test). In a more detailed study, nine different ponies received four treatments: d-glucose orally, d-glucose iv, oats, and commercial grain mix. Insulin, glucose, and incretin concentrations were measured before and after each treatment. All nine ponies showed similar iv responses, but five were markedly hyperresponsive to oral d-glucose and four were not. Insulin responsiveness to oral d-glucose was strongly associated with blood glucose concentrations and oral glucose bioavailability, presumably driven by glucose absorption/distribution, as there was no difference in glucose clearance rates. Insulin was also positively associated with the active amide of GLP-1 following d-glucose and grain. This study has confirmed a functional enteroinsular axis in ponies that likely contributes to insulin dysregulation that may predispose them to laminitis. Moreover, iv tests for IR are not reliable predictors of the oral response to dietary nonstructural carbohydrate.

  8. Modular design and development methodology for robotic multi-axis F/M sensors

    Science.gov (United States)

    Liang, Qiao-Kang; Zhang, Dan; Coppola, Gianmarc; Wu, Wan-Neng; Zou, Kun-Lin; Wang, Yao-Nan; Sun, Wei; Ge, Yun-Jian; Ge, Yu

    2016-04-01

    Accurate Force/Moment (F/M) measurements are required in many applications, and multi-axis F/M sensors have been utilized a wide variety of robotic systems since 1970s. A multi-axis F/M sensor is capable of measuring multiple components of force terms along x-, y-, z-axis (Fx, Fy, Fz), and the moments terms about x-, y- and z-axis (Mx, My and Mz) simultaneously. In this manuscript, we describe experimental and theoretical approaches for using modular Elastic Elements (EE) to efficiently achieve multi-axis, high-performance F/M sensors. Specifically, the proposed approach employs combinations of simple modular elements (e.g. lamella and diaphragm) in monolithic constructions to develop various multi-axis F/M sensors. Models of multi-axis F/M sensors are established, and the experimental results indicate that the new approach could be widely used for development of multi-axis F/M sensors for many other different applications.

  9. Modular design and development methodology for robotic multi-axis F/M sensors.

    Science.gov (United States)

    Liang, Qiao-Kang; Zhang, Dan; Coppola, Gianmarc; Wu, Wan-Neng; Zou, Kun-Lin; Wang, Yao-Nan; Sun, Wei; Ge, Yun-Jian; Ge, Yu

    2016-04-22

    Accurate Force/Moment (F/M) measurements are required in many applications, and multi-axis F/M sensors have been utilized a wide variety of robotic systems since 1970s. A multi-axis F/M sensor is capable of measuring multiple components of force terms along x-, y-, z-axis (Fx, Fy, Fz), and the moments terms about x-, y- and z-axis (Mx, My and Mz) simultaneously. In this manuscript, we describe experimental and theoretical approaches for using modular Elastic Elements (EE) to efficiently achieve multi-axis, high-performance F/M sensors. Specifically, the proposed approach employs combinations of simple modular elements (e.g. lamella and diaphragm) in monolithic constructions to develop various multi-axis F/M sensors. Models of multi-axis F/M sensors are established, and the experimental results indicate that the new approach could be widely used for development of multi-axis F/M sensors for many other different applications.

  10. Relationship between the hypothalamic-pituitary-adrenal-axis and fatty acid metabolism in recurrent depression

    NARCIS (Netherlands)

    Mocking, Roel J T; Ruhe, Eric; Assies, Johanna; Lok, Anja; Koeter, Maarten W J; Visser, Ieke; Bockting, Claudi L H; Schene, Aart H

    2013-01-01

    Alterations in hypothalamic-pituitary-adrenal (HPA)-axis activity and fatty acid (FA)-metabolism have been observed in (recurrent) major depressive disorder (MDD). Through the pathophysiological roles of FAs in the brain and cardiovascular system, a hypothesized relationship between HPA-axis activit

  11. Characterization of the hypothalamic-pituitary-adrenal-axis in familial longevity under resting conditions

    NARCIS (Netherlands)

    S.W. Jansen; F. Roelfsema; A.A. Akintola; N.Y. Oei; C.M. Cobbaert; B.E. Ballieux; J. van der Grond; R.G. Westendorp; H. Pijl; D. van Heemst

    2015-01-01

    Objective: The hypothalamic-pituitary-adrenal (HPA)-axis is the most important neuro-endocrine stress response system of our body which is of critical importance for survival. Disturbances in HPA-axis activity have been associated with adverse metabolic and cognitive changes. Humans enriched for lon

  12. Combined Structural Optimization and Aeroelastic Analysis of a Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Roscher, Björn; Ferreira, Carlos Simao; Bernhammer, Lars O.;

    2015-01-01

    Floating offshore wind energy poses challenges on the turbine design. A possible solution is vertical axis wind turbines, which are possibly easier to scale-up and require less components (lower maintenance) and a smaller floating structure than horizontal axis wind turbines. This paper presents...

  13. Evaluation of the P Wave Axis in Patients With Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Rezzan Deniz Acar

    2015-12-01

    Conclusion: P wave axis was found significantly increased in patients with SLE and positively correlated with SELENA-SLEDAI score. As the risk score increases in patients with SLE, P wave axis changes which may predict the risk of all-cause and cardiovascular mortality.

  14. Bouncing back - trauma and the HPA-axis in healthy adults

    Directory of Open Access Journals (Sweden)

    Ellen Renée Klaassens

    2010-12-01

    Full Text Available Dysregulation of the hypothalamic–pituitary–adrenal (HPA-axis is thought to underlie stress-related psychiatric disorders such as posttraumatic stress disorder (PTSD. Some studies have reported HPA-axis dysregulation in trauma-exposed (TE adults in the absence of psychiatric morbidity. In this dissertation we set out to unravel part of the mechanism that underlies the complex relations between trauma exposure, stress regulation, and psychopathology. Mentally healthy TE subjects were compared with non-trauma-exposed (NE healthy controls. To distinguish between the potential effects of childhood trauma and adulthood trauma, we included women exposed to childhood trauma as well as men who were exposed to trauma during adulthood. Basal HPA-axis functioning was assessed with salivary cortisol samples. HPA-axis reactivity was assessed with the dexamethasone/corticotropin-releasing hormone (Dex/CRH test. The results show that childhood trauma exposure is associated with an attenuated cortisol response after the Dex/CRH challenge test in women. In contrast, trauma exposure during adulthood was not associated with alterations in HPA-axis regulation after the Dex/CRH test. Neither childhood trauma nor adulthood trauma were associated with basal HPA-axis functioning. Childhood trauma rather than adulthood trauma may chronically affect HPA-axis functioning. Since the association between adulthood trauma and resilience to psychopathology cannot be explained by HPA-axis functioning alone, other factors must play a role.

  15. Biosynthesis of intestinal microvillar proteins. Expression of aminopeptidase N along the crypt-villus axis

    DEFF Research Database (Denmark)

    Danielsen, E M

    1984-01-01

    The expression of pig small-intestinal aminopeptidase N (EC 3.4.11.2) along the crypt-villus axis was studied in tangential sections of [35S]-methionine-labelled, organ-cultured explants. The only detectable molecular forms of aminopeptidase N along the crypt-villus axis were polypeptides of Mr 140...

  16. Hypothalamic Pituitary Adrenal Axis Functioning in Reactive and Proactive Aggression in Children

    Science.gov (United States)

    Lopez-Duran, Nestor L.; Olson, Sheryl L.; Hajal, Nastassia J.; Felt, Barbara T.; Vazquez, Delia M.

    2009-01-01

    The purpose of this study was to examine the association between hypothalamic-pituitary-adrenal axis (HPA-axis) reactivity and proactive and reactive aggression in pre-pubertal children. After a 30-min controlled base line period, 73 7-year-old children (40 males and 33 females) were randomly assigned to one of two experimental tasks designed to…

  17. Effortful Control and Parenting: Associations with HPA Axis Reactivity in Early Childhood

    Science.gov (United States)

    Kryski, Katie R.; Dougherty, Lea R.; Dyson, Margaret W.; Olino, Thomas M.; Laptook, Rebecca S.; Klein, Daniel N.; Hayden, Elizabeth P.

    2013-01-01

    While activation of the hypothalamic-pituitary-adrenal (HPA) axis is an adaptive response to stress, excessive HPA axis reactivity may be an important marker of childhood vulnerability to psychopathology. Parenting, including parent affect during parent-child interactions, may play an important role in shaping the developing HPA system; however,…

  18. Association analyses of depression and genes in the hypothalamus-pituitary-adrenal axis

    DEFF Research Database (Denmark)

    Buttenschøn, Henrietta Nørmølle; Krogh, Jesper; Nielsen, Marit Nyholm;

    2016-01-01

    OBJECTIVE: Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been reported in depression. The aim was to investigate the potential association between depression and seven genes regulating or interfering with the HPA axis, including the gene encoding angiotensin converting enzyme...

  19. Local Auxin Sources Orient the Apical-Basal Axis in Arabidopsis Embryos

    NARCIS (Netherlands)

    Robert, H.S.; Grones, P.; Stepanova, A.N.; Robles, L.M.; Lokerse, A.S.; Alonso, J.M.; Weijers, D.; Friml, J.

    2013-01-01

    Establishment of the embryonic axis foreshadows the main body axis of adults both in plants and in animals, but underlying mechanisms are considered distinct. Plants utilize directional, cell-to-cell transport of the growth hormone auxin [1 and 2] to generate an asymmetric auxin response that specif

  20. Kinematic equations to grind a helical drill point on a virtual axis drill sharpener

    Institute of Scientific and Technical Information of China (English)

    陈五一; 陈鼎昌

    2000-01-01

    The basic structure of a virtual axis drill grinder is presented in terms of the spatial vectors and thegrinding parameters calculated according to the geometry of a helical drill point. The kinematic equations for sharpening the drills on the virtual axis grinder are deduced using the grinding parameters via vector-matrix txansformation.

  1. An off-axis digital holographic microscope with quasimonochromatic partially spatially coherent illumination in transmission

    Science.gov (United States)

    Grebenyuk, Anton A.; Tarakanchikova, Yana V.; Ryabukho, Vladimir P.

    2014-10-01

    We propose an off-axis imaging approach for digital holographic microscopy (DHM) with quasimonochromatic partially spatially coherent illumination in transmission, which is intended to provide the advantages of off-axis partially coherent DHM imaging with a comparatively simple optical scheme. This approach does not require a diffraction grating for creating the off-axis modality and also allows for convenient control of the spatial frequency of carrier interference fringes for hologram sampling optimization. Theoretical analysis of the off-axis imaging process in this microscope is performed. An off-axis DHM based on the proposed approach is built and quantitative phase imaging of test objects is performed with suppressed coherent noise.

  2. Note: A compact three-axis optical force/torque sensor using photo-interrupters

    Science.gov (United States)

    Kim, Ji-Chul; Kim, Kyung-Soo; Kim, Soohyun

    2013-12-01

    By integrating four photo-interrupters in a cross-shaped structure, we developed a compact three-axis optical force/torque (F/T) sensor. The developed sensor has a diameter of 28 mm and a thickness of 7 mm. Despite simplicity and compactness, the experiments with a prototype of the proposed sensor demonstrate notably high accuracy. The RMS errors are 0.5% ± 0.1% of the maximum vertical force in z-axis, 1.9% ± 0.2% of the maximum torque in x-axis, and 2.0% ± 0.3% of the maximum torque in y-axis. It is expected that the proposed sensor allows cost-effective integration of robot systems requiring compact and multi-axis F/T sensors such as a walking assist robot.

  3. Note: A compact three-axis optical force/torque sensor using photo-interrupters.

    Science.gov (United States)

    Kim, Ji-Chul; Kim, Kyung-Soo; Kim, Soohyun

    2013-12-01

    By integrating four photo-interrupters in a cross-shaped structure, we developed a compact three-axis optical force/torque (F/T) sensor. The developed sensor has a diameter of 28 mm and a thickness of 7 mm. Despite simplicity and compactness, the experiments with a prototype of the proposed sensor demonstrate notably high accuracy. The RMS errors are 0.5% ± 0.1% of the maximum vertical force in z-axis, 1.9% ± 0.2% of the maximum torque in x-axis, and 2.0% ± 0.3% of the maximum torque in y-axis. It is expected that the proposed sensor allows cost-effective integration of robot systems requiring compact and multi-axis F/T sensors such as a walking assist robot. PMID:24387485

  4. Note: A compact three-axis optical force/torque sensor using photo-interrupters.

    Science.gov (United States)

    Kim, Ji-Chul; Kim, Kyung-Soo; Kim, Soohyun

    2013-12-01

    By integrating four photo-interrupters in a cross-shaped structure, we developed a compact three-axis optical force/torque (F/T) sensor. The developed sensor has a diameter of 28 mm and a thickness of 7 mm. Despite simplicity and compactness, the experiments with a prototype of the proposed sensor demonstrate notably high accuracy. The RMS errors are 0.5% ± 0.1% of the maximum vertical force in z-axis, 1.9% ± 0.2% of the maximum torque in x-axis, and 2.0% ± 0.3% of the maximum torque in y-axis. It is expected that the proposed sensor allows cost-effective integration of robot systems requiring compact and multi-axis F/T sensors such as a walking assist robot.

  5. Concentration of off-axis radiation by solar concentrators for space power

    Science.gov (United States)

    Jefferies, Kent S.

    1989-01-01

    Four types of off-axis radiation are discussed. These are: (1) small off-axis angles during walk-off, (2) large off-axis angles, (3) an extended off-axis source such as Earth albedo, and (4) miscellaneous off-axis sources including radio frequency sources and local point sources. A code named OFFSET has been developed to represent the solar concentrator being developed for Space Station Freedom. It is a detailed, ray-tracing model which represents 50 ray originating points on the Sun and reflections from 10 points on each of the 456 concentrator facets. Results of this code are generally similar to the PIXEL results although there are small differences due to the more detailed representations of the Sun and concentrator that were used in the OFFSET code.

  6. 2002–2012: 10 Years of Research Progress in Horizontal-Axis Marine Current Turbines

    Directory of Open Access Journals (Sweden)

    Kai-Wern Ng

    2013-03-01

    Full Text Available Research in marine current energy, including tidal and ocean currents, has undergone significant growth in the past decade. The horizontal-axis marine current turbine is one of the machines used to harness marine current energy, which appears to be the most technologically and economically viable one at this stage. A number of large-scale marine current turbines rated at more than 1 MW have been deployed around the World. Parallel to the development of industry, academic research on horizontal-axis marine current turbines has also shown positive growth. This paper reviews previous research on horizontal-axis marine current turbines and provides a concise overview for future researchers who might be interested in horizontal-axis marine current turbines. The review covers several main aspects, such as: energy assessment, turbine design, wakes, generators, novel modifications and environmental impact. Future trends for research on horizontal-axis marine current turbines are also discussed.

  7. Minimizing cross-axis sensitivity in grating-based optomechanical accelerometers.

    Science.gov (United States)

    Lu, Qianbo; Wang, Chen; Bai, Jian; Wang, Kaiwei; Lou, Shuqi; Jiao, Xufen; Han, Dandan; Yang, Guoguang; Liu, Dong; Yang, Yongying

    2016-04-18

    Cross-axis sensitivity of single-axis optomechanical accelerometers, mainly caused by the asymmetric structural design, is an essential issue primarily for high performance applications, which has not been systematically researched. This paper investigates the generating mechanism and detrimental effects of the cross-axis sensitivity of a high resoluion single-axis optomechanical accelerometer, which is composed of a grating-based cavity and an acceleration sensing chip consisting of four crab-shaped cantilevers and a proof mass. The modified design has been proposed and a prototype setup has been built based on the model of cross-axis sensitivity in optomechanical accelerometers. The characterization of the cross-axis sensitivity of a specific optomechanical accelerometer is quantitatively discussed for both mechanical and optical components by numerical simulation and theoretical analysis in this work. The analysis indicates that the cross-axis sensitivity decreases the contrast ratio of the interference signal and the acceleration sensitivity, as well as giving rise to an additional optical path difference, which would impact the accuracy of the accelerometer. The improved mechanical design is achieved by double side etching on a specific double-substrate-layer silicon-on-insulator (SOI) wafer to move the center of the proof mass to the support plane. The experimental results demonstrate that the modified design with highly symmetrical structure can suppress the cross-axis sensitivity significantly without compromising the sensitivity and resolution. The cross-axis sensitivity defined by the contrast ratio of the output signal drops to 2.19% /0.1g from 28.28%/0.1g under the premise that the acceleration sensitivity of this single-axis optomechanical accelerometer remains 1162.45V/g and the resolution remains 1.325μg. PMID:27137337

  8. Dynamic Stall on Vertical Axis Wind Turbine Blades

    Science.gov (United States)

    Dunne, Reeve

    In this study the dynamics of flow over the blades of vertical axis wind turbines was investigated using a simplified periodic motion to uncover the fundamental flow physics and provide insight into the design of more efficient turbines. Time-resolved, two-dimensional velocity measurements were made with particle image velocimetry on a wing undergoing pitching and surging motion to mimic the flow on a turbine blade in a non-rotating frame. Dynamic stall prior to maximum angle of attack and a leading edge vortex development were identified in the phase-averaged flow field and captured by a simple model with five modes, including the first two harmonics of the pitch/surge frequency identified using the dynamic mode decomposition. Analysis of these modes identified vortical structures corresponding to both frequencies that led the separation and reattachment processes, while their phase relationship determined the evolution of the flow. Detailed analysis of the leading edge vortex found multiple regimes of vortex development coupled to the time-varying flow field on the airfoil. The vortex was shown to grow on the airfoil for four convection times, before shedding and causing dynamic stall in agreement with 'optimal' vortex formation theory. Vortex shedding from the trailing edge was identified from instantaneous velocity fields prior to separation. This shedding was found to be in agreement with classical Strouhal frequency scaling and was removed by phase averaging, which indicates that it is not exactly coupled to the phase of the airfoil motion. The flow field over an airfoil undergoing solely pitch motion was shown to develop similarly to the pitch/surge motion; however, flow separation took place earlier, corresponding to the earlier formation of the leading edge vortex. A similar reduced-order model to the pitch/surge case was developed, with similar vortical structures leading separation and reattachment; however, the relative phase lead of the separation mode

  9. Axis IV--psychosocial and environmental problems--in the DSM-IV.

    Science.gov (United States)

    Ramirez, A; Ekselius, L; Ramklint, M

    2013-11-01

    The aim of this study was to further explore the properties of axis IV in the Diagnostic and statistical manual of mental disorders, 4th edition (DSM-IV). In a naturalistic cross-sectional design, a group (n = 163) of young (18-25 years old) Swedish psychiatric outpatients was assessed according to DSM-IV. Psychosocial and environmental problems/axis IV were evaluated through structured interviewing by a social worker and by self-assessment on a questionnaire. Reliability between professional assessment and self-assessment of axis IV was examined. Concurrent validity of axis IV was also examined. Reliability between professional and self-assessed axis IV was fair to almost perfect, 0.31-0.83, according to prevalence and bias-adjusted kappa. Categories of psychosocial stress and environmental problems were related to the presence of axis I disorders, co-morbidity, personality disorders and decreasing Global Assessment of Functioning (GAF) values. The revised axis IV according to DSM-IV seems to have concurrent validity, but is still hampered by limited reliability.

  10. Dynamic transitions in a model of the hypothalamic-pituitary-adrenal axis

    Science.gov (United States)

    Čupić, Željko; Marković, Vladimir M.; Maćešić, Stevan; Stanojević, Ana; Damjanović, Svetozar; Vukojević, Vladana; Kolar-Anić, Ljiljana

    2016-03-01

    Dynamic properties of a nonlinear five-dimensional stoichiometric model of the hypothalamic-pituitary-adrenal (HPA) axis were systematically investigated. Conditions under which qualitative transitions between dynamic states occur are determined by independently varying the rate constants of all reactions that constitute the model. Bifurcation types were further characterized using continuation algorithms and scale factor methods. Regions of bistability and transitions through supercritical Andronov-Hopf and saddle loop bifurcations were identified. Dynamic state analysis predicts that the HPA axis operates under basal (healthy) physiological conditions close to an Andronov-Hopf bifurcation. Dynamic properties of the stress-control axis have not been characterized experimentally, but modelling suggests that the proximity to a supercritical Andronov-Hopf bifurcation can give the HPA axis both, flexibility to respond to external stimuli and adjust to new conditions and stability, i.e., the capacity to return to the original dynamic state afterwards, which is essential for maintaining homeostasis. The analysis presented here reflects the properties of a low-dimensional model that succinctly describes neurochemical transformations underlying the HPA axis. However, the model accounts correctly for a number of experimentally observed properties of the stress-response axis. We therefore regard that the presented analysis is meaningful, showing how in silico investigations can be used to guide the experimentalists in understanding how the HPA axis activity changes under chronic disease and/or specific pharmacological manipulations.

  11. Analysis of nodal aberration properties in off-axis freeform system design.

    Science.gov (United States)

    Shi, Haodong; Jiang, Huilin; Zhang, Xin; Wang, Chao; Liu, Tao

    2016-08-20

    Freeform surfaces have the advantage of balancing off-axis aberration. In this paper, based on the framework of nodal aberration theory (NAT) applied to the coaxial system, the third-order astigmatism and coma wave aberration expressions of an off-axis system with Zernike polynomial surfaces are derived. The relationship between the off-axis and surface shape acting on the nodal distributions is revealed. The nodal aberration properties of the off-axis freeform system are analyzed and validated by using full-field displays (FFDs). It has been demonstrated that adding Zernike terms, up to nine, to the off-axis system modifies the nodal locations, but the field dependence of the third-order aberration does not change. On this basis, an off-axis two-mirror freeform system with 500 mm effective focal length (EFL) and 300 mm entrance pupil diameter (EPD) working in long-wave infrared is designed. The field constant aberrations induced by surface tilting are corrected by selecting specific Zernike terms. The design results show that the nodes of third-order astigmatism and coma move back into the field of view (FOV). The modulation transfer function (MTF) curves are above 0.4 at 20 line pairs per millimeter (lp/mm) which meets the infrared reconnaissance requirement. This work provides essential insight and guidance for aberration correction in off-axis freeform system design. PMID:27557003

  12. The relationship between personality disorders and Axis I psychopathology: deconstructing comorbidity.

    Science.gov (United States)

    Links, Paul S; Eynan, Rahel

    2013-01-01

    The purpose of this review is (a) to study and systematically review the recent literature examining the co-occurrence and relationships between Axis I psychiatric disorders and Axis II personality disorders, specifically the six originally proposed for the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5, and (b) to consider the clinical utility of the current Axis I and Axis II approach in the DSM-IV-TR and apply findings to state a position on the issue of collapsing together Axis I and Axis II. Community surveys or prospective cohort studies were reviewed as a priority. Our review indicates that the associations between clinical disorders and personality disorders clearly varied within each disorder and across the six personality disorders. Our understanding has advanced, particularly related to the clinical utility of comorbidity, and there may be sufficient evidence to support moving borderline personality disorder to Axis I. However, it seems premature to conclude that comorbidity is best conceptualized by having all disorders in a single category or by deleting disorders so that comorbidity is reduced. Our review suggests some priorities for future research into comorbidity, such as including personality disorders in future multivariate comorbidity models. PMID:23157449

  13. Age of Trauma Onset and HPA Axis Dysregulation Among Trauma-Exposed Youth.

    Science.gov (United States)

    Kuhlman, Kate Ryan; Vargas, Ivan; Geiss, Elisa G; Lopez-Duran, Nestor L

    2015-12-01

    The hypothalamic-pituitary-adrenal axis (HPA axis) is a pathway through which childhood trauma may increase risk for negative health outcomes. The HPA axis is sensitive to stress throughout development; however, few studies have examined whether timing of exposure to childhood trauma is related to differences in later HPA axis functioning. Therefore, we examined the association between age of first trauma and HPA axis functioning among adolescents, and whether these associations varied by sex. Parents of 97 youth (aged 9-16 years) completed the Early Trauma Inventory (ETI), and youth completed the Socially-Evaluated Cold-Pressor Task (SECPT). We measured salivary cortisol response to the SECPT, the cortisol awakening response, and diurnal regulation at home across 2 consecutive weekdays. Exposure to trauma during infancy related to delayed cortisol recovery from peak responses to acute stress, d = 0.23 to 0.42. Timing of trauma exposure related to diverging patterns of diurnal cortisol regulation for males, d = 0.55, and females, d = 0.57. Therefore, the HPA axis may be susceptible to developing acute stress dysregulation when exposed to trauma during infancy, whereas the consequences within circadian cortisol regulation may occur in the context of later trauma exposure and vary by sex. Further investigations are warranted to characterize HPA axis sensitivity to exposure to childhood trauma across child development.

  14. The Role of Anti-Phase Domains in InSb-Based Structures Grown on On-Axis and Off-Axis Ge Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, M. C.; Mishima, T. D.; Santos, M. B. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Hossain, K.; Holland, O. W. [Amethyst Research, Inc., 1405 4th Ave NW, Ardmore, OK 73401 (United States)

    2011-12-26

    Anti-phase domains form in InSb epilayers and InSb/Al{sub 0.20}In{sub 0.80}Sb single quantum wells when grown upon on-axis (001) Ge substrates by molecular beam epitaxy. Domain formation is partially suppressed through growth on Ge substrates with surfaces that are several degrees off the (001) or (211) axis. By using off-axis Ge substrates, room-temperature electron mobilities increased to {approx}60,000 cm{sup 2}/V-s and {approx}14,000 cm{sup 2}/V-s for a 4.0-{mu}m-thick InSb epilayer and a 25-nm InSb quantum well, respectively.

  15. 基于Rampart模块的Axis2 Web服务安全研究%ON AXIS2 WEB SERVICE SECURITY BASED ON RAMPART MODULE

    Institute of Scientific and Technical Information of China (English)

    马安峰; 赵逢禹

    2009-01-01

    随着Web Service技术与应用的发展,Web Service 安全问题日益突出.Axis2 作为新一代的Web服务开发平台,具有模块化和可扩展的新特性.首先介绍Axis2 和Rampart 的工作原理,然后通过一个应用场景具体说明Rampart 作为Axis2的一个安全模块,在客户端与服务端安全配置方法和回调函数的设计,以及模块是如何实现WS-Security 规范中的XML加密来保证Web服务的安全.

  16. Identification and characterization of HPA-axis reactivity endophenotypes in a cohort of female PTSD patients.

    Science.gov (United States)

    Zaba, Monika; Kirmeier, Thomas; Ionescu, Irina A; Wollweber, Bastian; Buell, Dominik R; Gall-Kleebach, Dominique J; Schubert, Christine F; Novak, Bozidar; Huber, Christine; Köhler, Katharina; Holsboer, Florian; Pütz, Benno; Müller-Myhsok, Bertram; Höhne, Nina; Uhr, Manfred; Ising, Marcus; Herrmann, Leonie; Schmidt, Ulrike

    2015-05-01

    Analysis of the function of the hypothalamic-pituitary-adrenal (HPA)-axis in patients suffering from posttraumatic stress disorder (PTSD) has hitherto produced inconsistent findings, inter alia in the Trier Social Stress Test (TSST). To address these inconsistencies, we compared a sample of 23 female PTSD patients with either early life trauma (ELT) or adult trauma (AT) or combined ELT and AT to 18 age-matched non-traumatized female healthy controls in the TSST which was preceded by intensive baseline assessments. During the TSST, we determined a variety of clinical, psychological, endocrine and cardiovascular parameters as well as expression levels of four HPA-axis related genes. Using a previously reported definition of HPA-axis responsive versus non-responsive phenotypes, we identified for the first time two clinically and biologically distinct HPA-axis reactivity subgroups of PTSD. One subgroup ("non-responders") showed a blunted HPA-axis response and distinct clinical and biological characteristics such as a higher prevalence of trauma-related dissociative symptoms and of combined AT and ELT as well as alterations in the expression kinetics of the genes encoding for the mineralocorticoid receptor (MR) and for FK506 binding protein 51 (FKBP51). Interestingly, this non-responder subgroup largely drove the relatively diminished HPA axis response of the total cohort of PTSD patients. These findings are limited by the facts that the majority of patients was medicated, by the lack of traumatized controls and by the relatively small sample size. The here for the first time identified and characterized HPA-axis reactivity endophenotypes offer an explanation for the inconsistent reports on HPA-axis function in PTSD and, moreover, suggest that most likely other factors than HPA-axis reactivity play a decisive role in determination of PTSD core symptom severity.

  17. Evaluation of a Blade Force Measurement System for a Vertical Axis Wind Turbine Using Load Cells

    OpenAIRE

    Morgan Rossander; Eduard Dyachuk; Senad Apelfröjd; Kristian Trolin; Anders Goude; Hans Bernhoff; Sandra Eriksson

    2015-01-01

    Unique blade force measurements on an open site straight-bladed vertical axis wind turbine have been performed. This paper presents a method for measuring the tangential and normal forces on a 12-kW vertical axis wind turbine prototype with a three-bladed H-rotor. Four single-axis load cells were installed in-between the hub and the support arms on one of the blades. The experimental setup, the measurement principle, together with the necessary control and measurement system are described. Th...

  18. Effects of Temperature on Weak Principal Axis of Twisted Fiber Loop

    Institute of Scientific and Technical Information of China (English)

    XU Ling; YAO Shou-quan

    2004-01-01

    Theoretically and experimentally, the effects of temperature on the weak principal axis of twisted optical fiber loop are analyzed, and the results show that the location of the pair of weak principal axis will drift with temperature change, which will deteriorate the stability of system when applied to sensor system. In this paper, the influence of phase drift of weak principal axis on the performance of optical fiber current sensor is mainly predicted theoretically. Our research results will provide a beneficial reference for improving optical fiber sensor system.

  19. Description of multi-quasiparticle bands by the tilted axis cranking model 21.60.-n; High K rotational bands; Tilted axis cranking; Multi-quasiparticle configurations

    CERN Document Server

    Frauendorf, S

    2000-01-01

    The selfconsistent cranking approach is extended to the case of rotation about an axis which is tilted with respect to the principal axes of the deformed potential (Tilted Axis Cranking). Expressions for the energies and the intra bands electro-magnetic transition probabilities are given. The mean field solutions are interpreted in terms of quantal rotational states. The construction of the quasiparticle configurations and the elimination of spurious states is discussed. The application of the theory to high spin data is demonstrated by analyzing the multi-quasiparticle bands in the nuclides with N=102,103 and Z=71,72,73.

  20. Comparison of Efficiencies of Solar Tracker systems with static panel Single- Axis Tracking System and Dual-Axis Tracking System with Fixed Mount

    OpenAIRE

    Dhanabal.R; Bharathi.V; Ranjitha.R; Ponni.A; Deepthi.S; Mageshkannan.P

    2013-01-01

    Electricity plays a key role now in our daily lives but the energy sources to electric power has been used in abundance and so researchers were compelled to find an alternate source of power leading to the discovery of solar energy. Solar energy is inexhaustible and eco-friendly and can be converted into electricityusing photovoltaic panels. These panels can be used in a fixed form or used in a solar tracking system for single axis as well as for dual axis. In a fixed form their efficiency is...

  1. Design and realization of test system for testing parallelism and jumpiness of optical axis of photoelectric equipment

    Science.gov (United States)

    Shi, Sheng-bing; Chen, Zhen-xing; Qin, Shao-gang; Song, Chun-yan; Jiang, Yun-hong

    2014-09-01

    With the development of science and technology, photoelectric equipment comprises visible system, infrared system, laser system and so on, integration, information and complication are higher than past. Parallelism and jumpiness of optical axis are important performance of photoelectric equipment,directly affect aim, ranging, orientation and so on. Jumpiness of optical axis directly affect hit precision of accurate point damage weapon, but we lack the facility which is used for testing this performance. In this paper, test system which is used fo testing parallelism and jumpiness of optical axis is devised, accurate aim isn't necessary and data processing are digital in the course of testing parallelism, it can finish directly testing parallelism of multi-axes, aim axis and laser emission axis, parallelism of laser emission axis and laser receiving axis and first acuualizes jumpiness of optical axis of optical sighting device, it's a universal test system.

  2. Transient stability of synchronous generators with two-axis slip frequency excitation

    Energy Technology Data Exchange (ETDEWEB)

    Morsy, M.S.; Amer, H.H.; Badr, M.A.; El-Serafi, A.M.

    1983-04-01

    Investigations have indicated the possibility of operating two-axis synchronous generators (a machine which has two identical field windings: one on the d-axis and the other on the q-axis) asynchronously when the field windings are excited by slip frequency alternating currents. Such generators are free from the conventional steady-state stability limitations of the conventional synchronous machines and retain the advantage of reactive power control. This paper presents a study of the transient stability characteristics of such generators as affected by its excitation control and input governing systems when they operate synchronously before the occurrence of the disturbance. The results show that such unregulated two-axis synchronous generators with slip frequency excitation have superior transient stability limits compared with conventional alternators. These generators, when properly controlled, can have also improved transient stability characteristics compared with regulated conventional synchronous generators. The improvement realized depends on the optimal choice of the control system and parameters.

  3. Six-Axis Force-Torque Transducer for Mars 2018 Mission Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A transducer element that is hearty enough for a Mars lander mission needs to be developed so that a six-axis force and torque transducer is possible. The technical...

  4. [Growth Hormone-Insulin Growth Factor I (GH-IGF-I) axis and growth].

    Science.gov (United States)

    Castell, A-L; Sadoul, J-L; Bouvattier, C

    2013-10-01

    Normal human linear growth results from an evolutionary process expressing the sum effect of multiple genes. The growth hormone (GH) - insulin like growth factor (IGF)-I axis is one of the main actors in the growth process. Defects in this axis can be responsible for short or tall stature. Short stature is defined as smaller than - 2 standard deviations (SD). It is a very common reason for consultation in pediatrics; indeed, 2.5 % of children are concerned. Multiple causes make diagnosis difficult. In this article, we detail the most common constitutional causes of small size, including those related to a defect in the GH-IGF-I axis. Then, we report, the first results of the clinical and genetic study conducted on 213 patients with gigantism. Tall stature is defined by a height superior to 2 SD. Finally, recent work linking epigenetics and growth - via signaling pathways of GH-IGF-I axis - will be presented.

  5. Population pharmacokinetic/pharmacodynamic modelling of the hypothalamic-pituitary-gonadal axis

    DEFF Research Database (Denmark)

    Tornøe, Christoffer Wenzel

    2005-01-01

    The present thesis deals with different aspects of population pharmacokinetic/ pharmacodynamic (PK/PD) modelling of the male hypothalamic-pituitary-go-nadal (HPG) axis. The thesis consists of a summary report and five scientific research papers. An overview of the main topics covered in the thesis......). The main objective of the work underlying this thesis was to develop mechanism-based population PK/PD models of the HPG axis. The HPG axis is a multivariate closed-loop control system consisting of regulatory hormonal feedback mechanisms. The number and complexity of the physiological mechanisms involved...... in such models makes them difficult to develop and are often too complex to be conveniently described by empirical models. Hence, the use of SDEs in population PK/PD modelling was used as a tool to systematically develop a mechanism-based model of the HPG axis following treatment with gonadotropin...

  6. Lagrangian neoclassical transport theory applied to the region near the magnetic axis

    Energy Technology Data Exchange (ETDEWEB)

    Satake, Shinsuke [The Graduate Univ. for Advanced Studies, Dept. of Fusion Science, Toki, Gifu (Japan); Okamoto, Masao; Sugama, Hideo [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2002-06-01

    Neoclassical transport theory around the magnetic axis of a tokamak is studied, in which relatively wide ''potato'' orbits play an important role in transport. Lagrangian formulation of transport theory, which has been investigated to reflect finiteness of guiding-center orbit widths to transport equations, is developed in order to analyze neoclassical transport near the axis for a low-collisionality plasma. The treatment of self-collision term in Lagrangian formulation is revised to retain momentum conservation property of it. With directly reflecting the orbital properties of all the types of orbits in calculation, the ion thermal conductivity around the axis is found to decrease than from that predicted by conventional neoclassical theory. This result supports recent numerical simulations which show the reduction of thermal conductivity near the magnetic axis. (author)

  7. Distribution of three microvillar enzymes along the small intestinal crypt-villus axis

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Niels-Christiansen, L L; Poulsen, M D;

    1994-01-01

    of the axis, whereas ApN is found mainly in the villar and upper crypt enterocytes. All three enzymes are detected in the basolateral membrane at all levels along the crypt-villus axis, although ApN and S-I only occurred at low intensities in the villus region. The microvillar/basolateral labelling...... ratio for the three enzymes increases to a varying degree for the three enzymes along the axis suggesting that the sorting efficiency to the apical membrane improves at least for ApN and S-I as the cells mature. These findings might indicate that the enterocytes change from a transcytotic to a direct......Aminopeptidase N (ApN), dipeptidyl peptidase IV (DPP IV) and sucrose-isomaltase (S-I) are differentially expressed along the pig jejunum crypt-villus axis. Quantitative immunoelectron microscopy and enzyme cytochemistry show that DPP IV and S-I are expressed in enterocytes along the entire length...

  8. Rapid fabrication of miniature lens arrays by four-axis single point diamond machining.

    Science.gov (United States)

    McCall, Brian; Tkaczyk, Tomasz S

    2013-02-11

    A novel method for fabricating lens arrays and other non-rotationally symmetric free-form optics is presented. This is a diamond machining technique using 4 controlled axes of motion - X, Y, Z, and C. As in 3-axis diamond micro-milling, a diamond ball endmill is mounted to the work spindle of a 4-axis ultra-precision computer numerical control (CNC) machine. Unlike 3-axis micro-milling, the C-axis is used to hold the cutting edge of the tool in contact with the lens surface for the entire cut. This allows the feed rates to be doubled compared to the current state of the art of micro-milling while producing an optically smooth surface with very low surface form error and exceptionally low radius error.

  9. Update on stress and depression: the role of the hypothalamic-pituitary-adrenal (HPA axis

    Directory of Open Access Journals (Sweden)

    Mello Andrea de Abreu Feijó de

    2003-01-01

    Full Text Available Over the past 50 years, relationships between stress and the neurobiological changes seen in psychiatric disorders have been well-documented. A major focus of investigations in this area has been the role of the hypothalamic-pituitary-adrenal (HPA axis, both as a marker of stress response and as a mediator of additional downstream pathophysiologic changes. This review examines the emerging literature concerning the relationship between stress, HPA axis function, and depression, as well as the role of early life stress as an important risk factor for HPA axis dysregulation. The more recent studies reviewed suggest that the prominence of HPA axis hyperactivity in adults with depressive and anxiety disorders may constitute a link between the occurrence of adversity in childhood and the development of adult psychopathology

  10. Design Of Rotor Blade For Vertical Axis Wind Turbine Using Double Aerofoil

    DEFF Research Database (Denmark)

    Chougule, Prasad; Ratkovich, Nicolas Rios; Kirkegaard, Poul Henning;

    . In this current work two aerofoils are used to design a rotor blade for a vertical axis wind turbine to improve the power efficiency on the rotor. Double aerofoil blade design consists of a main aerofoil and a slat aerofoil. The parameters related to position and orientation of the slat aerofoil with respect......Nowadays, small vertical axis wind turbines are receiving more attention compared to horizontal wind turbines due to their suitability in urban use because they generate less noise, have bird free turbines and lower cost. There is few vertical axis wind turbines design with good power curve....... However, the efficiency of power extraction has not been improved. Therefore, an attempt has been made to utilize high lift technology in practice for vertical axis wind turbines in order to improve power efficiency. High lift is obtained by double aerofoil elements mainly used in aeroplane wing design...

  11. Indications of c-axis Charge Transport in Hole Doped Triangular Antiferromagnets

    Institute of Scientific and Technical Information of China (English)

    LIANG Ying; LIU Bin; FENG Shi-Ping

    2004-01-01

    The c-axis charge transport of the hole doped triangular antiferromagnet is investigated within the tJ model by considering the incoherent interlayer hopping.It is shown that the c-axis charge transport of the hole doped triangular antiferromagnet is essentially determined by the scattering from the in-plane fluctuation.The c-axis conductivity spectrum shows a lov-energy peak and the unusual high-energy broad band,while the c-axis resistivity is characterized by a crossover from the high temperature metallic-like behavior to the Iow temperature insulating-like behavior,which is qualitatively consistent with those of the hole doped square lattice antiferromagnet.

  12. The development and testing of a novel cross axis wind turbine

    Science.gov (United States)

    Chong, W. T.; Muzammil, W. K.; Gwani, M.; Wong, K. H.; Fazlizan, A.; Wang, C. T.; Poh, S. C.

    2016-06-01

    A novel cross axis wind turbine (CAWT) which comprises of a cross axis blades arrangement was presented and investigated experimentally. The CAWT is a new type of wind turbine that extracts wind energy from airflow coming from the horizontal and vertical directions. The wind turbine consists of three vertical blades and six horizontal blades arranged in a cross axis orientation. Hubs in the middle of the CAWT link the horizontal and vertical blades through connectors to form the CAWT. The study used a 45° deflector to guide the oncoming airflow upward (vertical wind direction). The results from the study showed that the CAWT produced significant improvements in power output and rotational speed performance compared to a conventional straight-bladed vertical axis wind turbine (VAWT).

  13. Characterization of reactively sputtered c-axis aligned nanocrystalline InGaZnO4

    International Nuclear Information System (INIS)

    Crystallinity and texturing of RF sputtered c-axis aligned crystal InGaZnO4 (CAAC IGZO) thin films were quantified using X-ray diffraction techniques. Above 190 °C, nanocrystalline films with an X-ray peak at 2θ = 30° (009 planes) developed with increasing c-axis normal texturing up to 310 °C. Under optimal conditions (310 °C, 10% O2), films exhibited a c-axis texture full-width half-maximum of 20°. Cross-sectional high-resolution transmission electron microscopy confirmed these results, showing alignment variation of ±9° over a 15 × 15 nm field of view and indicating formation of much larger aligned domains than previously reported. At higher deposition temperatures, c-axis alignment was gradually lost as polycrystalline films developed

  14. Characterization of reactively sputtered c-axis aligned nanocrystalline InGaZnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, David M.; Zhu, Bin; Ast, Dieter G.; Thompson, Michael O. [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Levin, Barnaby D. A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Muller, David A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Kavli Institute for Nanoscale Science, Cornell University, Ithaca, New York 14853 (United States); Greene, Raymond G. [Corning Incorporated, Corning, New York 14831 (United States)

    2014-12-29

    Crystallinity and texturing of RF sputtered c-axis aligned crystal InGaZnO{sub 4} (CAAC IGZO) thin films were quantified using X-ray diffraction techniques. Above 190 °C, nanocrystalline films with an X-ray peak at 2θ = 30° (009 planes) developed with increasing c-axis normal texturing up to 310 °C. Under optimal conditions (310 °C, 10% O{sub 2}), films exhibited a c-axis texture full-width half-maximum of 20°. Cross-sectional high-resolution transmission electron microscopy confirmed these results, showing alignment variation of ±9° over a 15 × 15 nm field of view and indicating formation of much larger aligned domains than previously reported. At higher deposition temperatures, c-axis alignment was gradually lost as polycrystalline films developed.

  15. [Growth Hormone-Insulin Growth Factor I (GH-IGF-I) axis and growth].

    Science.gov (United States)

    Castell, A-L; Sadoul, J-L; Bouvattier, C

    2013-10-01

    Normal human linear growth results from an evolutionary process expressing the sum effect of multiple genes. The growth hormone (GH) - insulin like growth factor (IGF)-I axis is one of the main actors in the growth process. Defects in this axis can be responsible for short or tall stature. Short stature is defined as smaller than - 2 standard deviations (SD). It is a very common reason for consultation in pediatrics; indeed, 2.5 % of children are concerned. Multiple causes make diagnosis difficult. In this article, we detail the most common constitutional causes of small size, including those related to a defect in the GH-IGF-I axis. Then, we report, the first results of the clinical and genetic study conducted on 213 patients with gigantism. Tall stature is defined by a height superior to 2 SD. Finally, recent work linking epigenetics and growth - via signaling pathways of GH-IGF-I axis - will be presented. PMID:24356290

  16. Characterization of the Hypothalamic-Pituitary-Adrenal-Axis in Familial Longevity under Resting Conditions

    DEFF Research Database (Denmark)

    Jansen, Steffy W; Roelfsema, Ferdinand; Akintola, Abimbola A;

    2015-01-01

    OBJECTIVE: The hypothalamic-pituitary-adrenal (HPA)-axis is the most important neuro-endocrine stress response system of our body which is of critical importance for survival. Disturbances in HPA-axis activity have been associated with adverse metabolic and cognitive changes. Humans enriched...... for longevity have less metabolic and cognitive disturbances and therefore diminished activity of the HPA axis may be a potential candidate mechanism underlying healthy familial longevity. Here, we compared 24-h plasma ACTH and serum cortisol concentration profiles and different aspects of the regulation...... of the HPA-axis in offspring from long-lived siblings, who are enriched for familial longevity and age-matched controls. DESIGN: Case-control study within the Leiden Longevity study cohort consisting of 20 middle-aged offspring of nonagenarian siblings (offspring) together with 18 partners (controls...

  17. Normalized Point Source Sensitivity for Off-Axis Optical Performance Evaluation of the Thirty Meter Telescope

    Science.gov (United States)

    Seo, Byoung-Joon; Nissly, Carl; Troy, Mitchell; Angeli, George

    2010-01-01

    The Normalized Point Source Sensitivity (PSSN) has previously been defined and analyzed as an On-Axis seeing-limited telescope performance metric. In this paper, we expand the scope of the PSSN definition to include Off-Axis field of view (FoV) points and apply this generalized metric for performance evaluation of the Thirty Meter Telescope (TMT). We first propose various possible choices for the PSSN definition and select one as our baseline. We show that our baseline metric has useful properties including the multiplicative feature even when considering Off-Axis FoV points, which has proven to be useful for optimizing the telescope error budget. Various TMT optical errors are considered for the performance evaluation including segment alignment and phasing, segment surface figures, temperature, and gravity, whose On-Axis PSSN values have previously been published by our group.

  18. Impact of Sleep and Its Disturbances on Hypothalamo-Pituitary-Adrenal Axis Activity

    OpenAIRE

    Marcella Balbo; Rachel Leproult; Eve Van Cauter

    2010-01-01

    The daily rhythm of cortisol secretion is relatively stable and primarily under the influence of the circadian clock. Nevertheless, several other factors affect hypothalamo-pituitary-adrenal (HPA) axis activity. Sleep has modest but clearly detectable modulatory effects on HPA axis activity. Sleep onset exerts an inhibitory effect on cortisol secretion while awakenings and sleep offset are accompanied by cortisol stimulation. During waking, an association between cortisol secretory bursts and...

  19. Bouncing back - trauma and the HPA-axis in healthy adults

    OpenAIRE

    Ellen Renée Klaassens

    2010-01-01

    Background Dysregulation of the hypothalamic–pituitary–adrenal (HPA)-axis is thought to underlie stress-related psychiatric disorders such as posttraumatic stress disorder (PTSD). Some studies have reported HPA-axis dysregulation in trauma-exposed (TE) adults in the absence of psychiatric morbidity. In this dissertation we set out to unravel part of the mechanism that underlies the complex relations between trauma exposure, stress regulation, and psychopathology. Method Mentally healthy TE su...

  20. Process simulation for 5-axis machining using generalized milling tool geometries

    OpenAIRE

    Özkırımlı, Ömer Mehmet; Ozkirimli, Omer Mehmet; Budak, Erhan

    2010-01-01

    Multi-axis machining (especially 5-axis machining) is widely used in precision machining for automotive, aerospace and die-mold manufacturing. The goal in precision machining is to increase production while meeting high part quality needs which can be achieved through decision of appropriate process parameters considering machine tool constraints (such as power and torque), chatter-free operations and part quality. In order to predict and decide on optimal process parameters, simulation model...

  1. STRONG DAMPING OF THE C-AXIS PLASMON IN HIGH-T-C CUPRATE SUPERCONDUCTORS

    NARCIS (Netherlands)

    Kim, J.H; Somal, H.S; Czyzyk, M.T; der Marel, D.van; Wittlin, A.; Gerrits, A.M.; Duijn, V.H.M.; Hien, N.T.; Menovsky, A.A.

    1995-01-01

    We analyze the infrared reflectivity of La1.85Sr0.15CuO4 single crystals with E parallel to the c-axis. The plasma edge at around 6 meV (50 cm(-1)), which occurs only for T axis plasma frequ

  2. Hypothalamic-pituitary-adrenal axis modulation of GABAergic neuroactive steroids influences ethanol sensitivity and drinking behavior

    OpenAIRE

    Morrow, A. Leslie; Porcu, Patrizia; Boyd, Kevin N.; Grant, Kathleen A.

    2006-01-01

    Activation of the hypothalamic-pituitary-adrenal (HPA) axis leads to élévations in γ-aminobutyric acid (GABA)-ergic neuroactive steroids that enhance GABA neurotransmission and restore homeostasis following stress. This régulation of the HPA axis maintains healthy brain function and protects against neuropsychiatrie disease. Ethanol sensitivity is influenced by élévations in neuroactive steroids that enhance the GABAergic effects of ethanol, and mayprevent excessive drinking in rodents and hu...

  3. Fish schooling as a basis for vertical axis wind turbine farm design

    OpenAIRE

    Whittlesey, Robert W.; Liska, Sebastian; Dabiri, John O.

    2010-01-01

    Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases...

  4. 如何用Axis2开发Web Service服务

    Institute of Scientific and Technical Information of China (English)

    唐青

    2007-01-01

    Web Service是一种新的web应用程序分支.Apache Axis是较受欢迎的web service开发平台之一.主要介绍如果利用Axis2.1.0开发Web服务以及如何利用Axis2所提供的客户端API进行Web服务的调用.

  5. Chronic stress suppresses the expression of cutaneous hypothalamic-pituitary-adrenocortical axis elements and melanogenesis.

    Directory of Open Access Journals (Sweden)

    Silin Pang

    Full Text Available Chronic stress can affect skin function, and some skin diseases might be triggered or aggravated by stress. Stress can activate the central hypothalamic-pituitary-adrenocortical (HPA axis, which causes glucocorticoid levels to increase. The skin has HPA axis elements that react to environmental stressors to regulate skin functions, such as melanogenesis. This study explores the mechanism whereby chronic stress affects skin pigmentation, focusing on the HPA axis, and investigates the role of glucocorticoids in this pathway. We exposed C57BL/6 male mice to two types of chronic stress, chronic restraint stress (CRS and chronic unpredictable mild stress (CUMS. Mice subjected to either stress condition showed reduced melanogenesis. Interestingly, CRS and CUMS triggered reductions in the mRNA expression levels of key factors involved in the HPA axis in the skin. In mice administered corticosterone, decreased melanin synthesis and reduced expression of HPA axis elements were observed. The reduced expression of HPA axis elements and melanogenesis in the skin of stressed mice were reversed by RU486 (a glucocorticoid receptor antagonist treatment. Glucocorticoids had no significant inhibitory effect on melanogenesis in vitro. These results suggest that, high levels of serum corticosterone induced by chronic stress can reduce the expression of elements of the skin HPA axis by glucocorticoid-dependent negative feedback. These activities can eventually result in decreased skin pigmentation. Our findings raise the possibility that chronic stress could be a risk factor for depigmentation by disrupting the cutaneous HPA axis and should prompt dermatologists to exercise more caution when using glucocorticoids for treatment.

  6. Traveling theta waves along the entire septo-temporal axis of the hippocampus

    OpenAIRE

    Patel, Jagdish; Fujisawa, Shigeyoshi; Berényi, Antal; Royer, Sébastien; Buzsáki, György

    2012-01-01

    A topographical relationship exists between the hippocampus-entorhinal cortex and the neocortex. However, it is not known how these anatomical connections are utilized during information exchange and behavior. We recorded theta oscillations along the entire extent of the septo-temporal axis of the hippocampal CA1 pyramidal layer. While the frequency of theta oscillation remained same along the entire long axis, the amplitude and coherence between recording sites decreased from dorsal to ventr...

  7. Experimental Study of Aerodynamic Characteristics for Horizontal Axis Wind Turbine and Performance Evaluation

    OpenAIRE

    Dai Yuanjun; Wen Caifeng

    2012-01-01

    This study using two different airfoil of horizontal axis wind turbine in order to evaluate the performance good or bad with unit area of power generation. First, under the low speed wind tunnel, two different airfoil of horizontal axis wind turbine on experimental study of the aerodynamic characteristics, got the power curve of wind turbine; Then, based on the wind resource date in 2008 from four areas in Inner Mongolia, which was provided by the China meteorological date sharing service sys...

  8. Design and dynamic analysis of single-axis integrated inertia measurement device

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The structure and measurement theory of a single-axis integrated inertia measurement device are discussed in this paper.The acceleration and angle velocity can be detected by the proposed sensor at the same time.The kinetic model of the device is also established.In addition,the signal generation of the single-axis integrated inertiameasurement device is analyzed and simulated.The results of the model are consistent with simulation result.

  9. Stress and serial adult metamorphosis: multiple roles for the stress axis in socially regulated sex change

    OpenAIRE

    Solomon-Lane, Tessa K.; Crespi, Erica J.; Matthew Scott Grober

    2013-01-01

    Socially regulated sex change in teleost fishes is a striking example of social status information regulating biological function in the service of reproductive success. The establishment of social dominance in sex changing species is translated into a cascade of changes in behavior, physiology, neuroendocrine function, and morphology that transforms a female into a male, or vice versa. The hypothalamic-pituitary-interrenal axis (HPI, homologous to HP-adrenal axis in mammals and birds) has ...

  10. Electron Traps in GaAs Grown by Molecular Beam Epitaxy on On-axis (100 and Off-axis Substrates

    Directory of Open Access Journals (Sweden)

    R. Sarmiento

    2003-06-01

    Full Text Available Deep level transient spectroscopy (DLTS was used to characterize the electron traps present in the bulkGaAs grown by molecular beam epitaxy (MBE on on-axis (100 and off-axis (4° towards the (111 Adirection substrates. Two electron traps were obtained for each sample having identical correspondingpeak locations in the DLTS spectra. The layer grown on the on-axis substrate has electron traps withactivation energies of EC–0.454 eV and EC–0.643 eV and capture cross-sections of 1.205 x 10-14 cm2 and3.88 x 10-15 cm2, respectively. The layer grown on the off-axis substrate has traps with activation energiesof EC–0.454 eV and EC–0.723 eV and capture cross-sections of 2.060 x 10-14 cm2 and 4.40 x 10-14 cm2.The electron traps are possibly the M4 (or EL3 and EL2 (or EB4 traps commonly found in GaAs layers.Due to the high trap concentrations obtained and to the non-uniform trap concentration profile, Asdesorption may be considerable during growth.

  11. Nanoscratch Characterization of GaN Epilayers on c- and a-Axis Sapphire Substrates

    Directory of Open Access Journals (Sweden)

    Wen Hua-Chiang

    2010-01-01

    Full Text Available Abstract In this study, we used metal organic chemical vapor deposition to form gallium nitride (GaN epilayers on c- and a-axis sapphire substrates and then used the nanoscratch technique and atomic force microscopy (AFM to determine the nanotribological behavior and deformation characteristics of the GaN epilayers, respectively. The AFM morphological studies revealed that pile-up phenomena occurred on both sides of the scratches formed on the GaN epilayers. It is suggested that cracking dominates in the case of GaN epilayers while ploughing during the process of scratching; the appearances of the scratched surfaces were significantly different for the GaN epilayers on the c- and a-axis sapphire substrates. In addition, compared to the c-axis substrate, we obtained higher values of the coefficient of friction (μ and deeper penetration of the scratches on the GaN a-axis sapphire sample when we set the ramped force at 4,000 μN. This discrepancy suggests that GaN epilayers grown on c-axis sapphire have higher shear resistances than those formed on a-axis sapphire. The occurrence of pile-up events indicates that the generation and motion of individual dislocation, which we measured under the sites of critical brittle transitions of the scratch track, resulted in ductile and/or brittle properties as a result of the deformed and strain-hardened lattice structure.

  12. Propagation evolution of an off-axis high-order cylindrical vector beam.

    Science.gov (United States)

    Li, Yang; Zhu, Zhuqing; Wang, Xiaolei; Gong, Liping; Wang, Ming; Nie, Shouping

    2014-11-01

    The propagation characteristics of an off-axis high-order cylindrical vector beam (OHCVB) are studied in this paper. The analytic expressions for the electric field and intensity distribution of the OHCVB propagating in free space are presented, to our knowledge for the first time. The transverse intensity of the OHCVB, different from that of the input Gaussian beam, does not have an axially symmetric distribution, owing to a slight dislocation between the polarization singularity located in the vector field generator and the center point of the Gaussian beam. Numerical results show that the intensity distribution during propagation strongly depends on the propagation distance, dislocation displacement, and topological charge. Accompanied by beam expansion, the intensity distribution of the OHCVB tends to eventually become steady, and the dark core of the vector beam will disappear gradually during the process of propagation. Moreover, with the increase of the topological charge, more energy will be transferred from the x axis to the y axis, and the annular intensity is split into two parts along the y-axis direction. The results help us to investigate the dynamic propagation behaviors of the HCVB under the off-axis condition and also guide the calibration of the off-axis high-order cylindrical vector field in practice. PMID:25401345

  13. The A/P axis in echinoderm ontogeny and evolution: evidence from fossils and molecules

    Science.gov (United States)

    Peterson, K. J.; Arenas-Mena, C.; Davidson, E. H.

    2000-01-01

    Even though echinoderms are members of the Bilateria, the location of their anterior/posterior axis has remained enigmatic. Here we propose a novel solution to the problem employing three lines of evidence: the expression of a posterior class Hox gene in the coeloms of the nascent adult body plan within the larva; the anatomy of certain early fossil echinoderms; and finally the relation between endoskeletal plate morphology and the associated coelomic tissues. All three lines of evidence converge on the same answer, namely that the location of the adult mouth is anterior, and the anterior/posterior axis runs from the mouth through the adult coelomic compartments. This axis then orients the animal such that there is but a single plane of symmetry dividing the animal into left and right halves. We tentatively hypothesize that this plane of symmetry is positioned along the dorsal/ventral axis. These axis identifications lead to the conclusion that the five ambulacra are not primary body axes, but instead are outgrowths from the central anterior/posterior axis. These identifications also shed insight into several other evolutionary mysteries of various echinoderm clades such as the independent evolution of bilateral symmetry in irregular echinoids, but do not elucidate the underlying mechanisms of the adult coelomic architecture.

  14. GRB off-axis afterglows and the emission from the accompanying supernovae

    CERN Document Server

    Kathirgamaraju, Adithan; Giannios, Dimitrios

    2016-01-01

    Gamma-Ray Burst (GRB) afterglows are likely produced in the shock that is driven as the GRB jet interacts with the external medium. Long duration GRBs are also associated with powerful supernovae (SN). We consider the optical and radio afterglows of long GRBs for both blasts viewed along the jet axis ("on-axis" afterglows) and misaligned observes ("off-axis" afterglows). Comparing the optical emission from the afterglow with that of the accompanying SN, using SN 1998bw as an archetype, we find that only a few percent of afterglows viewed off-axis are brighter than the SN. For observable optical off-axis afterglows the viewing angle is at most twice the half-opening angle of the GRB jet. Radio off-axis afterglows should be detected with upcoming radio surveys within a few hundred Mpc. We propose that these surveys will act as "radio triggers," and that dedicated radio facilities should follow-up these sources. Follow-ups can unveil the presence of the radio supernova remnant, if present. In addition, they can ...

  15. Proto-Model of an Infrared Wide-Field Off-Axis Telescope

    CERN Document Server

    Kim, Sanghyuk; Chang, Seunghyuk; Kim, Geon Hee; Yang, Sun Choel; Kim, Myung Sang; Lee, Sungho; Lee, Hanshin; 10.5303/JKAS.2010.43.5.169

    2010-01-01

    We develop a proto-model of an off-axis reflective telescope for infrared wide-field observations based on the design of Schwarzschild-Chang type telescope. With only two mirrors, this design achieves an entrance pupil diameter of 50 mm and an effective focal length of 100 mm. We can apply this design to a mid-infrared telescope with a field of view of 8 deg X 8 deg. In spite of the substantial advantages of off-axis telescopes in the infrared compared to refractive or on-axis reflective telescopes, it is known to be difficult to align the mirrors in off-axis systems because of their asymmetric structures. Off-axis mirrors of our telescope are manufactured at the Korea Basic Science Institute (KBSI). We analyze the fabricated mirror surfaces by fitting polynomial functions to the measured data. We accomplish alignment of this two-mirror off-axis system using a ray tracing method. A simple imaging test is performed to compare a pinhole image with a simulated prediction.

  16. Stressing diabetes? The hidden links between insulinotropic peptides and the HPA axis.

    Science.gov (United States)

    Diz-Chaves, Yolanda; Gil-Lozano, Manuel; Toba, Laura; Fandiño, Juan; Ogando, Hugo; González-Matías, Lucas C; Mallo, Federico

    2016-08-01

    Diabetes mellitus exerts metabolic stress on cells and it provokes a chronic increase in the long-term activity of the hypothalamus-pituitary-adrenocortical (HPA) axis, perhaps thereby contributing to insulin resistance. GLP-1 receptor (GLP-1R) agonists are pleiotropic hormones that not only affect glycaemic and metabolic control, but they also produce many other effects including activation of the HPA axis. In fact, several of the most relevant effects of GLP-1 might involve, at least in part, the modulation of the HPA axis. Thus, the anorectic activity of GLP-1 could be mediated by increasing CRF at the hypothalamic level, while its lipolytic effects could imply a local increase in glucocorticoids and glucocorticoid receptor (GC-R) expression in adipose tissue. Indeed, the potent activation of the HPA axis by GLP-1R agonists occurs within the range of therapeutic doses and with a short latency. Interestingly, the interactions of GLP-1 with the HPA axis may underlie most of the effects of GLP-1 on food intake control, glycaemic metabolism, adipose tissue biology and the responses to stress. Moreover, such activity has been observed in animal models (mice and rats), as well as in normal humans and in type I or type II diabetic patients. Accordingly, better understanding of how GLP-1R agonists modulate the activity of the HPA axis in diabetic subjects, especially obese individuals, will be crucial to design new and more efficient therapies for these patients.

  17. Seizure-induced disinhibition of the HPA axis increases seizure susceptibility.

    Science.gov (United States)

    O'Toole, Kate K; Hooper, Andrew; Wakefield, Seth; Maguire, Jamie

    2014-01-01

    Stress is the most commonly reported precipitating factor for seizures. The proconvulsant actions of stress hormones are thought to mediate the effects of stress on seizure susceptibility. Interestingly, epileptic patients have increased basal levels of stress hormones, including corticotropin-releasing hormone (CRH) and corticosterone, which are further increased following seizures. Given the proconvulsant actions of stress hormones, we proposed that seizure-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis may contribute to future seizure susceptibility. Consistent with this hypothesis, our data demonstrate that pharmacological induction of seizures in mice with kainic acid or pilocarpine increases circulating levels of the stress hormone, corticosterone, and exogenous corticosterone administration is sufficient to increase seizure susceptibility. However, the mechanism(s) whereby seizures activate the HPA axis remain unknown. Here we demonstrate that seizure-induced activation of the HPA axis involves compromised GABAergic control of CRH neurons, which govern HPA axis function. Following seizure activity, there is a collapse of the chloride gradient due to changes in NKCC1 and KCC2 expression, resulting in reduced amplitude of sIPSPs and even depolarizing effects of GABA on CRH neurons. Seizure-induced activation of the HPA axis results in future seizure susceptibility which can be blocked by treatment with an NKCC1 inhibitor, bumetanide, or blocking the CRH signaling with Antalarmin. These data suggest that compromised GABAergic control of CRH neurons following an initial seizure event may cause hyperexcitability of the HPA axis and increase future seizure susceptibility.

  18. Food and the circadian activity of the hypothalamic-pituitary-adrenal axis

    Directory of Open Access Journals (Sweden)

    A.M.O. Leal

    1997-12-01

    Full Text Available Temporal organization is an important feature of biological systems and its main function is to facilitate adaptation of the organism to the environment. The daily variation of biological variables arises from an internal time-keeping system. The major action of the environment is to synchronize the internal clock to a period of exactly 24 h. The light-dark cycle, food ingestion, barometric pressure, acoustic stimuli, scents and social cues have been mentioned as synchronizers or" zeitgebers". The circadian rhythmicity of plasma corticosteroids has been well characterized in man and in rats and evidence has been accumulated showing daily rhythmicity at every level of the hypothalamic-pituitary-adrenal (HPA axis. Studies of restricted feeding in rats are of considerable importance because they reveal feeding as a major synchronizer of rhythms in HPA axis activity. The daily variation of the HPA axis stress response appears to be closely related to food intake as well as to basal activity. In humans, the association of feeding and HPA axis activity has been studied under physiological and pathological conditions such as anorexia nervosa, bulimia, malnutrition, obesity, diabetes mellitus and Cushing's syndrome. Complex neuroanatomical pathways and neurochemical circuitry are involved in feeding-associated HPA axis modulation. In the present review we focus on the interaction among HPA axis rhythmicity, food ingestion, and different nutritional and endocrine states

  19. Design and implementation of five-axis transformation function in CNC system

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2014-04-01

    Full Text Available To implement five-axis functions in CNC system, based on domestic system Lan Tian series, an improved design method for the system software structure is proposed in this paper. The numerical control kernel of CNC system is divided into the task layer and the motion layer. A five-axis transformation unit is integrated into the motion layer. After classifying five-axis machines into different types and analyzing their geometry information, the five-axis kinematic library is designed according to the abstract factory pattern. Furthermore, by taking CA spindle-tilting machine as an example, the forward and the inverse kinematic transformations are deduced. Based on the new software architecture and the five-axis kinematic library, algorithms of RTCP (rotation tool center point control and 3D radius compensation for end-milling are designed and realized. The milling results show that, with five-axis functions based on such software structure, the instructions with respect to the cutter’s position and orientation can be directly carried out in the CNC system.

  20. ANALYSIS OF THE MAGNETIC FIELD MEASURED BY A ROTATING HALL PROBE IN A SOLENOID TO LOCATE ITS MAGNETIC AXIS.

    Energy Technology Data Exchange (ETDEWEB)

    KPONOU,A.; PIKIN,A.; BEEBE,E.; ALESSI,J.

    2000-11-06

    We have analyzed the motion of a Hall probe, which is rotated about an axis that is arbitrarily displaced and oriented with respect to the magnetic axis of a solenoid. We outline how the magnetic field measured by the rotating Hall probe can be calculated. We show how to compare theoretical results with actual measurements, to determine the displacement and orientation of the axis of rotation of the probe from the magnetic axis. If the center of rotation of the probe is known by surveying, the corresponding point on the magnetic axis of the solenoid can be located. This is applied to a solenoid that was built for BNL by Oxford Instruments.

  1. Evolution of hypothalamus-pituitary growth axis among fish, amphibian, birds and mammals

    Directory of Open Access Journals (Sweden)

    Moaeen-Ud-Din M.

    2015-01-01

    Full Text Available Hypothalamus-pituitary growth axis (HP growth axis regulates animal growth and development in pre-natal and post natal life governed by many factors. However, until recently, the evolutionary history of this axis among lineages is not understood. Aim of the present study was to understand the major events in evolution and evolutionary history and trend of HP growth axis. The diversity among Homo sapience, Mus musculus, Rattus norvegicus, Gallus gallus, Danio rerio and Xenopus laevis was determined for genes involved in HP growth axis in current study. Sequences of HP growth axis genes were retrieved from NCBI (http://www.ncbi.nlm.nih.gov/. Nucleotide diversity using Kimura’s two-parameter method; codon-based test of positive selection using the Nei-Gojobori; equality of evolutionary rate with Tajima's relative rate test and phylogenetic history using the RelTime method were estimated in MEGA6. Estimates of the coefficients of evolutionary differentiation based on nucleotides and amino acids substitution patterns of HP growth axis genes showed contrasting evolutionary patterns among the lineages. The results demonstrated that although these genes might have crucial functional roles in each of the species, however, their sequence divergence did not necessarily reflect similar molecular evolution among the species. Codon-based test of positive selection revealed that Human vs Mouse, Chicken vs Rat, Human vs Rat and Mouse vs Rat had similar and higher non synonymous substitutions (P > 0.05. Higher rate of non-synonymous substitutions at similar orthologs level among species indicated a similar positive selection pressure in these species. Results for relative rate test assessed with the chi-squared test showed difference on unique mutations among lineages at synonymous and non synonymous sites except Chicken vs Mouse, Human vs Mouse, Chicken vs Rat, Human vs Rat and Mouse vs Rat. This indicated that the mutagenic process that generates

  2. The different roles of glucocorticoids in the hippocampus and hypothalamus in chronic stress-induced HPA axis hyperactivity.

    Directory of Open Access Journals (Sweden)

    Li-Juan Zhu

    Full Text Available Hypothalamus-pituitary-adrenal (HPA hyperactivity is observed in many patients suffering from depression and the mechanism underling the dysfunction of HPA axis is not well understood. Chronic stress has a causal relationship with the hyperactivity of HPA axis. Stress induces the over-synthesis of glucocorticoids, which will arrive at all the body containing the brain. It is still complicated whether glucocorticoids account for chronic stress-induced HPA axis hyperactivity and in which part of the brain the glucocorticoids account for chronic stress-induced HPA axis hyperactivity. Here, we demonstrated that glucocorticoids were indispensable and sufficient for chronic stress-induced hyperactivity of HPA axis. Although acute glucocorticoids elevation in the hippocampus and hypothalamus exerted a negative regulation of HPA axis, we found that chronic glucocorticoids elevation in the hippocampus but not in the hypothalamus accounted for chronic stress-induced hyperactivity of HPA axis. Chronic glucocorticoids exposure in the hypothalamus still exerted a negative regulation of HPA axis activity. More importantly, we found mineralocorticoid receptor (MR - neuronal nitric oxide synthesis enzyme (nNOS - nitric oxide (NO pathway mediated the different roles of glucocorticoids in the hippocampus and hypothalamus in regulating HPA axis activity. This study suggests that the glucocorticoids in the hippocampus play an important role in the development of HPA axis hyperactivity and the glucocorticoids in the hypothalamus can't induce hyperactivity of HPA axis, revealing new insights into understanding the mechanism of depression.

  3. The different roles of glucocorticoids in the hippocampus and hypothalamus in chronic stress-induced HPA axis hyperactivity.

    Science.gov (United States)

    Zhu, Li-Juan; Liu, Meng-Ying; Li, Huan; Liu, Xiao; Chen, Chen; Han, Zhou; Wu, Hai-Yin; Jing, Xing; Zhou, Hai-Hui; Suh, Hoonkyo; Zhu, Dong-Ya; Zhou, Qi-Gang

    2014-01-01

    Hypothalamus-pituitary-adrenal (HPA) hyperactivity is observed in many patients suffering from depression and the mechanism underling the dysfunction of HPA axis is not well understood. Chronic stress has a causal relationship with the hyperactivity of HPA axis. Stress induces the over-synthesis of glucocorticoids, which will arrive at all the body containing the brain. It is still complicated whether glucocorticoids account for chronic stress-induced HPA axis hyperactivity and in which part of the brain the glucocorticoids account for chronic stress-induced HPA axis hyperactivity. Here, we demonstrated that glucocorticoids were indispensable and sufficient for chronic stress-induced hyperactivity of HPA axis. Although acute glucocorticoids elevation in the hippocampus and hypothalamus exerted a negative regulation of HPA axis, we found that chronic glucocorticoids elevation in the hippocampus but not in the hypothalamus accounted for chronic stress-induced hyperactivity of HPA axis. Chronic glucocorticoids exposure in the hypothalamus still exerted a negative regulation of HPA axis activity. More importantly, we found mineralocorticoid receptor (MR) - neuronal nitric oxide synthesis enzyme (nNOS) - nitric oxide (NO) pathway mediated the different roles of glucocorticoids in the hippocampus and hypothalamus in regulating HPA axis activity. This study suggests that the glucocorticoids in the hippocampus play an important role in the development of HPA axis hyperactivity and the glucocorticoids in the hypothalamus can't induce hyperactivity of HPA axis, revealing new insights into understanding the mechanism of depression.

  4. Binocular Coordination of the Human Vestibulo-Ocular Reflex during Off-axis Pitch Rotation

    Science.gov (United States)

    Wood, S. J.; Reschke, M. F.; Kaufman, G. D.; Black, F. O.; Paloski, W. H.

    2006-01-01

    Head movements in the sagittal pitch plane typically involve off-axis rotation requiring both vertical and horizontal vergence ocular reflexes to compensate for angular and translational motion relative to visual targets of interest. The purpose of this study was to compare passive pitch VOR responses during rotation about an Earth-vertical axis (canal only cues) with off-axis rotation (canal and otolith cues). Methods. Eleven human subjects were oscillated sinusoidally at 0.13, 0.3 and 0.56 Hz while lying left-side down with the interaural axis either aligned with the axis of rotation or offset by 50 cm. In a second set of measurements, twelve subjects were also tested during sinusoidally varying centrifugation over the same frequency range. The modulation of vertical and horizontal vergence ocular responses was measured with a binocular videography system. Results. Off-axis pitch rotation enhanced the vertical VOR at lower frequencies and enhanced the vergence VOR at higher frequencies. During sinusoidally varying centrifugation, the opposite trend was observed for vergence, with both vertical and vergence vestibulo-ocular reflexes being suppressed at the highest frequency. Discussion. These differential effects of off-axis rotation over the 0.13 to 0.56 Hz range are consistent with the hypothesis that otolith-ocular reflexes are segregated in part on the basis of stimulus frequency. At the lower frequencies, tilt otolith-ocular responses compensate for declining canal input. At higher frequencies, translational otolith-ocular reflexes compensate for declining visual contributions to the kinematic demands required for fixating near targets.

  5. Light curves and spectra from off-axis gamma-ray bursts

    Science.gov (United States)

    Salafia, O. S.; Ghisellini, G.; Pescalli, A.; Ghirlanda, G.; Nappo, F.

    2016-10-01

    If gamma-ray burst prompt emission originates at a typical radius, and if material producing the emission moves at relativistic speed, then the variability of the resulting light curve depends on the viewing angle. This is due to the fact that the pulse evolution time-scale is Doppler contracted, while the pulse separation is not. For off-axis viewing angles θview ≳ θjet + Γ-1, the pulse broadening significantly smears out the light-curve variability. This is largely independent of geometry and emission processes. To explore a specific case, we set up a simple model of a single pulse under the assumption that the pulse rise and decay are dominated by the shell curvature effect. We show that such a pulse observed off-axis is (i) broader, (ii) softer and (iii) displays a different hardness-intensity correlation with respect to the same pulse seen on-axis. For each of these effects, we provide an intuitive physical explanation. We then show how a synthetic light curve made by a superposition of pulses changes with increasing viewing angle. We find that a highly variable light curve (as seen on-axis) becomes smooth and apparently single-pulsed (when seen off-axis) because of pulse overlap. To test the relevance of this fact, we estimate the fraction of off-axis gamma-ray bursts detectable by Swift as a function of redshift, finding that a sizeable fraction (between 10 per cent and 80 per cent) of nearby (z < 0.1) bursts are observed with θview ≳ θjet + Γ-1. Based on these results, we argue that low-luminosity gamma-ray bursts are consistent with being ordinary bursts seen off-axis.

  6. The use of a beryllium Hopkinson bar to characterize in-axis and cross-axis accelerometer response in shock environments

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, V.I.; Brown, F.A.

    1997-05-01

    The characteristics of a piezoresistive accelerometer in shock environments are being studied at Sandia National Laboratories in the Mechanical Shock Testing Laboratory. A beryllium Hopkinson bar capability has been developed to extend the understanding of the piezoresistive accelerometer, in two mechanical configurations and with and without mechanical isolation, in the high frequency, high shock environments where measurements are being made. In this paper, recent measurements with beryllium single and split-Hopkinson bar configurations are described. The in axis performance of the piezoresistive accelerometer in mechanical isolation for frequencies of dc-30 kHz and shock magnitudes of up to 6,000 g as determined from measurements with a beryllium Hopkinson bar with a certified laser doppler vibrometer as the reference measurement are presented. Results of characterizations of the accelerometers subjected to cross axis shocks in a split beryllium Hopkinson bar configuration are also presented.

  7. A Wavelet Bicoherence-Based Quadratic Nonlinearity Feature for Translational Axis Condition Monitoring

    Directory of Open Access Journals (Sweden)

    Yong Li

    2014-01-01

    Full Text Available The translational axis is one of the most important subsystems in modern machine tools, as its degradation may result in the loss of the product qualification and lower the control precision. Condition-based maintenance (CBM has been considered as one of the advanced maintenance schemes to achieve effective, reliable and cost-effective operation of machine systems, however, current vibration-based maintenance schemes cannot be employed directly in the translational axis system, due to its complex structure and the inefficiency of commonly used condition monitoring features. In this paper, a wavelet bicoherence-based quadratic nonlinearity feature is proposed for translational axis condition monitoring by using the torque signature of the drive servomotor. Firstly, the quadratic nonlinearity of the servomotor torque signature is discussed, and then, a biphase randomization wavelet bicoherence is introduced for its quadratic nonlinear detection. On this basis, a quadratic nonlinearity feature is proposed for condition monitoring of the translational axis. The properties of the proposed quadratic nonlinearity feature are investigated by simulations. Subsequently, this feature is applied to the real-world servomotor torque data collected from the X-axis on a high precision vertical machining centre. All the results show that the performance of the proposed feature is much better than that of original condition monitoring features.

  8. Osmoregulatory actions of the GH/IGF axis in non-salmonid teleosts

    Science.gov (United States)

    Mancera, J.M.; McCormick, S.D.

    1998-01-01

    Salmonid fishes provided the first findings on the influence of the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis on osmoregulation in teleost fishes. Recent studies on non-salmonid species, however, indicate that this physiological action of the GH/IGF-I axis is not restricted to salmonids or anadromous fishes. GH-producing cells in the pituitary of fish acclimated to different salinities show different degrees of activation depending on the species studied. Plasma GH levels either increase or do not change after transfer of fish from freshwater to seawater. Treatment with GH or IGF-I increases salinity tolerance and/or increases gill Na+,K+-ATPase activity of killifish (Fundulus heteroclitus), tilapia (Oreochromis mossambicus and Oreochromis niloticus) and striped bass (Morone saxatilis). As in salmonids, a positive interaction between GH and cortisol for improving hypoosmoregulatory capacity has been described in tilapia (O. mossambicus). Research on the osmoregulatory role of the GH/IGF-I axis is derived from a small number of teleost species. The study of more species with different osmoregulary patterns will be necessary to fully clarify the osmoregulatory role of GH/IGF-I axis in fish. The available data does suggest, however, that the influence of the GH/IGF-I axis on osmoregulation may be a common feature of euryhalinity in teleosts. Copyright (C) 1998 Elsevier Science Inc.

  9. AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

    Science.gov (United States)

    Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

    2014-11-01

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  10. HPA-axis stress reactivity in youth depression: evidence of impaired regulatory processes in depressed boys.

    Science.gov (United States)

    Lopez-Duran, Nestor L; McGinnis, Ellen; Kuhlman, Kate; Geiss, Elisa; Vargas, Ivan; Mayer, Stefanie

    2015-01-01

    Given the link between youth depression and stress exposure, efforts to identify related biomarkers have involved examinations of stress regulation systems, including the hypothalamic-pituitary-adrenal (HPA) axis. Despite these vast efforts, the underlying mechanisms at play, as well as factors that may explain heterogeneity of past findings, are not well understood. In this study, we simultaneously examined separate components of the HPA-axis response (e.g. activation intensity, peak levels, recovery) to the Socially Evaluated Cold-Pressor Test in a targeted sample of 115 youth (age 9-16), recruited to overrepresent youth with elevated symptoms of depression. Among youth who displayed a cortisol response to the task, depression symptoms were associated with higher peak responses but not greater rate of activation or recovery in boys only. Among those who did not respond to the task, depression symptoms were associated with greater cortisol levels throughout the visit in boys and girls. Results suggest that depression symptoms are associated with a more prolonged activation of the axis and impaired recovery to psychosocial stressors primarily in boys. We discussed two potential mechanistic explanations of the link between depression symptoms and the duration of activation: (1) inhibitory shift (i.e. point at which the ratio of inhibitory and excitatory input into the axis shifts from greater excitatory to greater inhibitory input) or (2) inhibitory threshold (i.e. level of cortisol exposure required to activate the axis' feedback inhibition system).

  11. Analysis of wind turbine blade behavior under static dual axis loads

    Energy Technology Data Exchange (ETDEWEB)

    Son, Byung Jik [Korea Univ., Seoul (Korea, Republic of); Huh, Yong Hak; Kim, Dong Jin; Kim, Jong Il [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2012-03-15

    For the assessment of the performance of a wind turbine blade, a simulated loading test may be required. In this study, the blade behavior was investigated through numerical analysis using a dual axis loading test, closely simulating the real operation conditions. The blade structure for the 100 kw class wind turbine system was modeled using the finite element (FE) program ANSYS. The failure criteria and buckling analysis under dual axis loading were examined. The failure analysis, including fiber failure and inter fiber failure, was performed with Puck's failure criterion. As the dual axis load ratio increases, the relatively increased stress occurs at the trailing edge and skin surface 3300-3600mm away from the root. Furthermore, it is revealed that increasing the dual axis load ratio makes the location that is weakest against buckling move toward the root part. Thus, it is seen that the dual axis load test may be an essential requirement for the verification of blade performance.

  12. Adaptive sliding mode control of the A-axis used for blisk manufacturing

    Institute of Scientific and Technical Information of China (English)

    Zhao Pengbing; Shi Yaoyao

    2014-01-01

    As a key assembly in the 5-axis CNC machine tools, positioning precision of the A-axis directly affects the machining accuracy and surface quality of the parts. First of all, mechanical structure and control system of the A-axis are designed. Then, considering the influence of nonlin-ear friction, backlash, unmodeled dynamics, uncertain cutting force and other external disturbance on the control precision of the A-axis, an adaptive sliding mode control (ASMC) based on extended state observer (ESO) is proposed. ESO is employed to estimate the state variables of the unknown system and an adaptive law is adopted to compensate for the input dead-zone caused by friction, backlash and other nonlinear characteristics. Finally, stability of the closed-loop system is guaran-teed by the Lyapunov theory. Positioning experiments illustrate the perfect estimation of ESO and the stronger anti-interference and robustness of ASMC, which can improve the control precision of the A-axis by about 40 times. Processing experiments show that the ASMC can reduce the waviness, average error and roughness of the processed surface by 35.63%, 31.31%and 30.35%, respectively.

  13. Chronic Stress and Limbic-Hypothalamopituitary-Adrenal Axis (LHPA Response in Female Reproductive system

    Directory of Open Access Journals (Sweden)

    Farideh Zafari Zangeneh

    2009-12-01

    Full Text Available The hypothalamo-pituitary-adrenocortical (HPA axis is a critical adaptive system that maximizes survival potential in the face of physical or psychological challenge. The principal end products of the HPA axis, glucocorticoid hormones, act on multiple organ systems, including the brain, to maintain homeostatic balance. The brain is a target of stress, and the hippocampus is the first brain region, besides the hypothalamus, to be recognized as a target of glucocorticoids. These anatomical areas in brain are limbic system, and in particular the hippocampus, medial prefrontal cortex (mPFC and amigdal that have multiple control points in regulation of the hypothalamic–pituitary–adrenal (HPA axis. The studies show the prefrontal cortex (PFC plays an important role in the regulation of stress-induced hypothalamic–pituitary–adrenal (HPA activity and regulation of gonadal function in men and women is under the control of the HPA. This regulation is complex and sex steroids are important regulators of GnRH and gonadotropin release through classic feedback mechanisms in the hypothalamus and pituitary gland. Chronic stress can have a deleterious effect on the reproductive axis that, for females, is manifested in reduced pulsatile gonadotropin secretion and increased incidence of ovulatory abnormalities and infertility. The limbic–hypothalamic–pituitary–adrenal (LHPA axis suggests a functional role for gonadal steroids in the regulation of a female’s response to stress.

  14. Programming of the hypothalamic-pituitary-interrenal axis by maternal social status in zebrafish (Danio rerio).

    Science.gov (United States)

    Jeffrey, Jennifer D; Gilmour, Kathleen M

    2016-06-01

    The present study examined the effects of maternal social status, with subordinate status being a chronic stressor, on development and activity of the stress axis in zebrafish embryos and larvae. Female zebrafish were confined in pairs for 48 h to establish dominant/subordinate hierarchies; their offspring were reared to 144 h post-fertilization (hpf) and sampled at five time points over development. No differences were detected in maternal cortisol contribution, which is thought to be an important programmer of offspring phenotype. However, once zebrafish offspring began to synthesize cortisol de novo (48 hpf), larvae of dominant females exhibited significantly lower baseline cortisol levels than offspring of subordinate females. These lower cortisol levels may reflect reduced hypothalamic-pituitary-interrenal (HPI) axis activity, because corticotropin-releasing factor (crf) and cytochrome p450 side chain cleavage enzyme (p450scc) mRNA levels also were lower in larvae from dominant females. Moreover, baseline mRNA levels of HPI axis genes continued to be affected by maternal social status beyond 48 hpf. At 144 hpf, stress-induced cortisol levels were significantly lower in offspring of subordinate females. These results suggest programming of stress axis function in zebrafish offspring by maternal social status, emphasizing the importance of maternal environment and experience on offspring stress axis activity. PMID:27045091

  15. The critical importance of the fetal hypothalamus-pituitary-adrenal axis [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Charles E. Wood

    2016-01-01

    Full Text Available The fetal hypothalamus-pituitary-adrenal (HPA axis is at the center of mechanisms controlling fetal readiness for birth, survival after birth and, in several species, determination of the timing of birth. Stereotypical increases in fetal HPA axis activity at the end of gestation are critical for preparing the fetus for successful transition to postnatal life. The fundamental importance in fetal development of the endogenous activation of this endocrine axis at the end of gestation has led to the use of glucocorticoids for reducing neonatal morbidity in premature infants. However, the choice of dose and repetition of treatments has been controversial, raising the possibility that excess glucocorticoid might program an increased incidence of adult disease (e.g., coronary artery disease and diabetes. We make the argument that because of the critical importance of the fetal HPA axis and its interaction with the maternal HPA axis, dysregulation of cortisol plasma concentrations or inappropriate manipulation pharmacologically can have negative consequences at the beginning of extrauterine life and for decades thereafter.

  16. Hypothalamic-Pituitary-Adrenal Axis Programming after Recurrent Hypoglycemia during Development

    Directory of Open Access Journals (Sweden)

    Raghavendra Rao

    2015-08-01

    Full Text Available Permanent brain injury is a complication of recurrent hypoglycemia during development. Recurrent hypoglycemia also has adverse consequences on the neuroendocrine system. Hypoglycemia-associated autonomic failure, characterized by ineffective glucose counterregulation during hypoglycemia, is well described in children and adults on insulin therapy for diabetes mellitus. Whether recurrent hypoglycemia also has a programming effect on the hypothalamus-pituitary-adrenal cortex (HPA axis has not been well studied. Hypoglycemia is a potent stress that leads to increased glucocorticoid secretion in all age groups, including the perinatal period. Other conditions associated with exposure to excess glucocorticoid in the perinatal period have a programming effect on the HPA axis activity. Limited animal data suggest the possibility of similar programming effect after recurrent hypoglycemia in the postnatal period. The age at exposure to hypoglycemia likely determines the HPA axis response in adulthood. Recurrent hypoglycemia in the early postnatal period likely leads to a hyperresponsive HPA axis, whereas recurrent hypoglycemia in the late postnatal period lead to a hyporesponsive HPA axis in adulthood. The age-specific programming effects may determine the neuroendocrine response during hypoglycemia and other stressful events in individuals with history of recurrent hypoglycemia during development.

  17. Post-stress rumination predicts HPA axis responses to repeated acute stress.

    Science.gov (United States)

    Gianferante, Danielle; Thoma, Myriam V; Hanlin, Luke; Chen, Xuejie; Breines, Juliana G; Zoccola, Peggy M; Rohleder, Nicolas

    2014-11-01

    Failure of the hypothalamus-pituitary-adrenal (HPA) axis to habituate to repeated stress exposure is related with adverse health outcomes, but our knowledge of predictors of non-habituation is limited. Rumination, defined as repetitive and unwanted past-centered negative thinking, is related with exaggerated HPA axis stress responses and poor health outcomes. The aim of this study was to test whether post-stress rumination was related with non-habituation of cortisol to repeated stress exposure. Twenty-seven participants (n=13 females) were exposed to the Trier Social Stress Test (TSST) twice on consecutive afternoons. Post-stress rumination was measured after the first TSST, and HPA axis responses were assessed by measuring salivary cortisol 1 min before, and 1, 10, 20, 60, and 120 min after both TSSTs. Stress exposure induced HPA axis activation on both days, and this activation showed habituation indicated by lower responses to the second TSST (F=3.7, p=0.015). Post-stress rumination after the first TSST was associated with greater cortisol reactivity after the initial stress test (r=0.45, pHPA axis responses. This finding implicates rumination as one possible mechanism mediating maladaptive stress response patterns, and it might also offer a pathway through which rumination might lead to negative health outcomes.

  18. Metabotropic glutamate receptor-mediated signaling dampens the HPA axis response to restraint stress.

    Science.gov (United States)

    Evanson, Nathan K; Herman, James P

    2015-10-15

    Glutamate is an important neurotransmitter in the regulation of the neural portion of hypothalamus-pituitary-adrenal (HPA) axis activity, and signals through ionotropic and metabotropic receptors. In the current studies we investigated the role of hypothalamic paraventricular group I metabotropic glutamate receptors in the regulation of the HPA axis response to restraint stress in rats. Direct injection of the group I metabotropic glutamate receptor agonist 3,5-dihydroxyphenylglycine (DHPG) into the PVN prior to restraint leads to blunting of the HPA axis response in awake animals. Consistent with this result, infusion of the group I receptor antagonist hexyl-homoibotenic acid (HIBO) potentiates the HPA axis response to restraint. The excitatory effect of blocking paraventricular group I metabotropic glutamate signaling is blocked by co-administration of dexamethasone into the PVN. However, the inhibitory effect of DHPG is not affected by co-administration of the cannabinoid CB1 receptor antagonist AM-251 into the PVN. Together, these results suggest that paraventricular group I metabotropic glutamate receptor signaling acts to dampen HPA axis reactivity. This effect appears to be similar to the rapid inhibitory effect of glucocorticoids at the PVN, but is not mediated by endocannabinoid signaling.

  19. Determination of Flux-Gate Magnetometer Spin Axis Offsets with the Electron Drift Instrument

    Science.gov (United States)

    Plaschke, Ferdinand; Nakamura, Rumi; Giner, Lukas; Teubenbacher, Robert; Chutter, Mark; Leinweber, Hannes K.; Magnes, Werner

    2014-05-01

    Spin-stabilization of spacecraft enormously supports the in-flight calibration of onboard flux-gate magnetometers (FGMs): eight out of twelve calibration parameters can be determined by minimization of spin tone and harmonics in the calibrated magnetic field measurements. From the remaining four parameters, the spin axis offset is usually obtained by analyzing observations of Alfvénic fluctuations in the solar wind. If solar wind measurements are unavailable, other methods for spin axis offset determination need to be used. We present two alternative methods that are based on the comparison of FGM and electron drift instrument (EDI) data: (1) EDI measures the gyration periods of instrument-emitted electrons in the ambient magnetic field. They are inversely proportional to the magnetic field strength. Differences between FGM and EDI measured field strengths can be attributed to inaccuracies in spin axis offset, if the other calibration parameters are accurately known. (2) For EDI electrons to return to the spacecraft, they have to be sent out in perpendicular direction to the ambient magnetic field. Minimization of the variance of electron beam directions with respect to the FGM-determined magnetic field direction also yields an estimate of the spin axis offset. Prior to spin axis offset determination, systematic inaccuracies in EDI gyration period measurements and in the transformation of EDI beam directions into the FGM spin-aligned reference coordinate system have to be corrected. We show how this can be done by FGM/EDI data comparison, as well.

  20. Recognition Method of Aircraft Axis Direction Based on Morphological Skeleton and Hough Transform

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-bo; ZHUANG Zhi-hong; ZHENG Hua-li; ZHANG Qing-tai; HE Hong-jun

    2008-01-01

    Because of the limit of angle of view(AOV) of IR imaging seeker during the approach of missile and target, the detector can only get the partial image sequence of aircraft nose after "lose point". Recognizing the axis direction on the basis of partial IR image sequence is a key issue of the advanced IR imaging guide air-to-air missile faced. In this paper, a recognition method was proposed based on the morphological skeleton and modified Hough transform, and this method can recognize correctly the axis direction of aircraft nose in different poses during missile-target encounter. Firstly, the morphological skeleton transform was used for the extraction of skeleton features. Secondly, the modified Hough transform was used for the straight-lines detection. Finally, According to the relations between aircraft nose and axis and invariant of nose features in high-speed IR image sequence, the axis direction can be detected and calculated. Experimental results indicate that the method is feasible and effective, and the precision of axis direction recognized can meet the requirement of accurate burst control of GIF fuze.

  1. Adaptive sliding mode control of the A-axis used for blisk manufacturing

    Directory of Open Access Journals (Sweden)

    Zhao Pengbing

    2014-06-01

    Full Text Available As a key assembly in the 5-axis CNC machine tools, positioning precision of the A-axis directly affects the machining accuracy and surface quality of the parts. First of all, mechanical structure and control system of the A-axis are designed. Then, considering the influence of nonlinear friction, backlash, unmodeled dynamics, uncertain cutting force and other external disturbance on the control precision of the A-axis, an adaptive sliding mode control (ASMC based on extended state observer (ESO is proposed. ESO is employed to estimate the state variables of the unknown system and an adaptive law is adopted to compensate for the input dead-zone caused by friction, backlash and other nonlinear characteristics. Finally, stability of the closed-loop system is guaranteed by the Lyapunov theory. Positioning experiments illustrate the perfect estimation of ESO and the stronger anti-interference and robustness of ASMC, which can improve the control precision of the A-axis by about 40 times. Processing experiments show that the ASMC can reduce the waviness, average error and roughness of the processed surface by 35.63%, 31.31% and 30.35%, respectively.

  2. Expression of NMS and NMU2R in the pig reproductive axis during the estrus cycle and the effect of NMS on the reproductive axis in vitro.

    Science.gov (United States)

    Yang, Guihong; Su, Juan; Li, Xun; Yao, Yuan; Lei, Zhihai; Yang, Xizhi; Kou, Rui; Liu, Yanpeng

    2009-12-01

    Evidence has revealed that neuromedin S (NMS) and neuromedin U-receptor type-2 (NMU2R) mRNAs are expressed in the central nervous system and reproductive organs. Previous data indicated that variation of NMS and NMU2R was due to the phases of the adult rat hypothalamus estrus cycle. However, the expression and function of NMS in the pig reproductive axis remains unexplored. In this study, 16 virginal gilts were classified into four groups: proestrus, estrus, diestrus 1, and diestrus 2; the expression of NMS and NMU2R in the cyclic pig hypothalamus-pituitary-ovary axis was studied by reverse transcriptaion-polymerase chain reaction (RT-PCR), and the effect of NMS on the reproductive axis in vitro was detected by radioimmunoassay (RIA). The cloned pig NMS and NMU2R sequences were 82% and 90.2% identical to those of the corresponding human homologues, respectively. RT-PCR showed that NMS and NMU2R mRNA expression in the hypothalamus and pituitary changed with the estrus cycle, i.e., with the highest level in the proestrus group and the lowest in the estrus group. In the ovary, NMS and NMU2R expression was highest in the diestrus 2 group and the lowest in the proestrus group. In the in vitro study, different concentrations of NMS induced the release of gonadotropin-releasing hormone, luteinizing hormone, and estradiol at different levels of the reproductive axis. Taken together, the expression pattern of NMS during the estrus cycle and its role in reproductive hormones in vitro provide novel evidences of the potential roles of NMS in the regulation of pig reproduction.

  3. Nonparaxial propagation of a vectorial apertured off-axis Lorentz beam

    Institute of Scientific and Technical Information of China (English)

    Zhou Guo-Quan

    2009-01-01

    Based on the vectorial Rayleigh-Sommerfeld integral formula and the complex Gaussian expansion of the hard-edge aperture function, an analytical propagation expression for a nonparaxial vectorial off-axis Lorentz beam passing through a rectangular aperture is derived. The unapertured case, the far field expression and the scalar paraxial result are also presented as special cases of the general formulae, respectively. Some numerical examples are also given to show the propagation characteristics of a nonparaxial vectorial off-axis Lorentz beam through a rectangular aperture. It is indicated that the f parameter, the off-axis displacement and the truncation parameter all play an important role in determining nonparaxial propagation behaviour.

  4. A new robust gradient-based method for detection of symmetry axis

    Science.gov (United States)

    Hu, Jing; Wan, Qinqi; Hu, Yongli

    2015-12-01

    Symmetry axis extraction is an important part of the image feature detection. So far, various classical symmetry axes extraction algorithms have been proposed, such as the minimum-inertia-axis-based method, the SIFT-based method. If the input image is blurry, or it's difficult to extract feature points or corner points from input images, however, the above algorithms are difficult to obtain satisfied results. This paper presents a gradient-based method that can robustly extract symmetry axis from visual pattern. The key points of our methods are gradient calculation, symmetric weight calculation, and Hough Transform. Our method was evaluated on several datasets, including both blurred and smooth-edged cases. Experimental results demonstrated that our method achieves a more robust performance than previous methods.

  5. Ghrelin axis genes, peptides and receptors: recent findings and future challenges.

    Science.gov (United States)

    Seim, Inge; Josh, Peter; Cunningham, Peter; Herington, Adrian; Chopin, Lisa

    2011-06-20

    The ghrelin axis consists of the gene products of the ghrelin gene (GHRL), and their receptors, including the classical ghrelin receptor GHSR. While it is well-known that the ghrelin gene encodes the 28 amino acid ghrelin peptide hormone, it is now also clear that the locus encodes a range of other bioactive molecules, including novel peptides and non-coding RNAs. For many of these molecules, the physiological functions and cognate receptor(s) remain to be determined. Emerging research techniques, including proteogenomics, are likely to reveal further ghrelin axis-derived molecules. Studies of the role of ghrelin axis genes, peptides and receptors, therefore, promises to be a fruitful area of basic and clinical research in years to come.

  6. Anatomy of an eradication effort: Removing Hawaii's illegally introduced axis deer

    Science.gov (United States)

    Hess, Steven C.; Muise, Jake; Schipper, Jan

    2015-01-01

    In February 2011, a rancher in the rural southern part of Hawaii Island reported a large mammal on her land. Her call mobilized several agencies led by the Big Island Invasive Species Committee (BIISC), a partnership to prevent, detect, and control the establishment and spread of invasive species, to sit up and take notice. Agency biologists installed camera traps to identify the animal, and a few months later verified the diagnostic field marks of a chervid with spots. The animal in questions was a chital, or axis deer (Axis axis)--a species native to tropical and subtropical India. Although the deer are abundant on the islands of Molokai, Lānai, and Maui, officials knew they weren't capable of swimming across the notoriously treacherous ʻAlenuihāhā channel, and subsequently suspected human intervention.

  7. Adaptive Monte Carlo applied to uncertainty estimation in a five axis machine tool link errors identification

    CERN Document Server

    Andolfatto, Loïc; Lavernhe, Sylvain; 10.1016/j.ijmachtools.2011.03.006

    2011-01-01

    Knowledge of a machine tool axis to axis location errors allows compensation and correcting actions to be taken to enhance its volumetric accuracy. Several procedures exist, involving either lengthy individual test for each geometric error or faster single tests to identify all errors at once. This study focuses on the closed kinematic Cartesian chain method which uses a single setup test to identify the eight link errors of a five axis machine tool. The identification is based on volumetric error measurements for different poses with a non-contact measuring instrument called CapBall, developed in house. In order to evaluate the uncertainty on each identified error, a multi-output Monte Carlo approach is implemented. Uncertainty sources in the measurement and identification chain - such as sensors output, machine drift and frame transformation uncertainties - can be included in the model and propagated to the identified errors. The estimated uncertainties are finally compared to experimental results to assess...

  8. Development of five axis robotic system for an industrial neutron tomography imaging system

    International Nuclear Information System (INIS)

    Tomography is one of the latest techniques in the field of nondestructive testing. X-rays, gamma rays or neutrons are used as an energy source whereas five axis manipulator is designed to move the specimen across the beam. The 5 axis robotic system has been indigenously developed, designed, manufactured and tested to move up to 10 kg payload. Computer is necessary to process and store data and retrieve it for processing. The same computer is used for control of manipulator. Computer aided tomography is carried out for research and industrial use. Neutron beam will be used either for evaluation of organic materials in attenuation based measurements or for evaluation on the basis of neutron activation of materials like nuclear fuels. The paper describes the indigenously developed 5-axis robotic system as a part of a facility built around Kamini reactor at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam. (author). 4 figs

  9. Dynamic Analysis of a Floating Vertical Axis Wind Turbine Under Emergency Shutdown Using Hydrodynamic Brake

    DEFF Research Database (Denmark)

    Wang, K.; Hansen, Martin Otto Laver; Moan, T.

    2014-01-01

    axis wind turbine were carried out for emergency shutdown cases over a range of environmental conditions based on correlated wind and wave data. When generator failure happens, a brake should be applied to stop the acceleration of the rotor to prevent the rotor from overspeeding and subsequent disaster....... In addition to the traditional mechanical brake, a novel hydrodynamic brake was presented to apply to the shutdown case. The effects of the hydrodynamic brake on the platform motions and structural loads under normal operating conditions and during the emergency shutdown events were evaluated. The use of both......Emergency shutdown is always a challenge for an operating vertical axis wind turbine. A 5-MW vertical axis wind turbine with a Darrieus rotor mounted on a semi-submersible support structure was examined in this study. Coupled non-linear aero-hydro-servo-elastic simulations of the floating vertical...

  10. Realization Methodology of a 5-axis Spline Interpolator in an Open CNC System

    Institute of Scientific and Technical Information of China (English)

    Wang Yongzhang; Ma Xiongbo; Chen Liangji; Han Zhenyu

    2007-01-01

    By making use of the advantages of non-uniform rational B-spline (NURBS) curves to represent spatial curves, an instruction format with double NURBS curves suitable for 5-axis coordinated real-time interpolation is presented to replace the current 5-axis coordinated linear interpolation method defective in low-speed, low-accuracy and enormous numerical control (NC) files in sculptured surface machining. A generation procedure of the NC files with the presented format is introduced and the method to realize the interpolation in an open computer numerical control (CNC) system is developed by ourselves. These illustrated the feasibility of the proposed method and its capability of avoiding all the shortages of 5-axis linear interpolation method.

  11. Spatial re-orienting of visual attention along the horizontal or the vertical axis.

    Science.gov (United States)

    Macaluso, E; Patria, F

    2007-06-01

    Neuroimaging data indicate functional segregation between voluntary and stimulus-driven control of spatial attention in dorsal and ventral fronto-parietal regions, respectively. While recent evidences demonstrated location-specific attentional effects in dorsal regions, little is known about any location or direction selectivity within the ventral network. Here, we used a spatial cueing paradigm to investigate stimulus-driven spatial re-orienting along different axes (horizontal or vertical). We found that re-orienting of attention activated the ventral attentional network, irrespective of axis-orientation. Statistical comparisons between homologous regions in the two hemispheres revealed significant main effects of attention re-orienting (common activation for the two hemispheres), irrespective of leftward or rightward re-orienting along the horizontal axis, or re-orienting along the vertical axis. We conclude that in healthy volunteers, a bilateral ventral network controls spatial covert re-orienting, and that this system is multidirectional.

  12. Active Blade Pitch Control for Straight Bladed Darrieus Vertical Axis Wind Turbine of New Design

    DEFF Research Database (Denmark)

    Chougule, Prasad; Nielsen, Søren R.K.; Basu, Biswajit

    2013-01-01

    As Development of small vertical axis wind turbines (VAWT) for urban use is becoming an interesting topic both within industry and academia. However, there are few new designs of vertical axis turbines which are customized for building integration. These are getting importance because they operate...... at low rotational speed producing very less noise during operation, although these are less efficient than Horizontal Axis Wind Turbines (HAWT). The efficiency of a VAWT has been significantly improved by H-Darrieus VAWT design based on double airfoil technology as demonstrated by the authors...... in a previous publication. Further, it is well know that the variation of the blade pitch angle during the rotation improves the power efficiency. A blade pitch variation is implemented by active blade pitch control, which operates as per wind speed and position of the blade with respect to the rotor. A double...

  13. Neuromedins U and S involvement in the regulation of the hypothalamo - pituitary - adrenal axis.

    Directory of Open Access Journals (Sweden)

    Ludwik K. Malendowicz

    2012-12-01

    Full Text Available Abstract: We reviewed neuromedin U (NMU and neuromedin S (NMS involvement in the regulation of the hypothalamo - pituitary - adrenal (HPA axis function. NMU and NMS are structurally related and highly conserved neuropeptides. They exert biological effects via two GPCR receptors designated as NMUR1 and NMUR2 which show differential expression. NMUR1 is expressed predominantly at the periphery, while NMUR2 in the central nervous system. Elements of the NMU/NMS and their receptors network are also expressed in the HPA axis and progress in molecular biology techniques provided new information on their actions within this system. Several lines of evidence suggest that within the HPA axis NMU and NMS act at both hypothalamic and adrenal levels. Moreover, new data suggest that NMU and NMS are involved in central and peripheral control of the stress response.

  14. Off-vertical axis rotation: a test of the otolith-ocular reflex

    Science.gov (United States)

    Furman, J. M.; Schor, R. H.; Schumann, T. L.

    1992-01-01

    The vestibulo-ocular reflex was studied via off-vertical axis rotation (OVAR) in the dark. The axis of the turntable could be tilted from vertical by up to 30 degrees. Eye movements were measured with electro-oculography. Results from healthy asymptomatic subjects indicated that 1) a reliable otolith-induced response could be obtained during constant velocity OVAR using a velocity of 60 degrees/s with a tilt of 30 degrees; 2) constant velocity OVAR rotation was nausea-producing and, especially if subjects were rotated in the dark about an earth-vertical axis prior to being tilted, disorienting; and 3) sinusoidal OVAR produced minimal nausea; the eye movement response appeared to be the result of a combination of semicircular canal and otolith components. We conclude that OVAR has the potential of becoming a useful method for clinically assessing both the otolith-ocular reflex and semicircular canal-otolith interaction.

  15. Tooth brushing pattern classification using three-axis accelerometer and magnetic sensor for smart toothbrush.

    Science.gov (United States)

    Lee, Kang-Hwi; Lee, Jeong-Whan; Kim, Kyeong-Seop; Kim, Dong-Jun; Kim, Kyungho; Yang, Heui-Kyung; Jeong, Keesam; Lee, Byungchae

    2007-01-01

    The concept of intelligent toothbrush, capable of monitoring brushing motion, orientation through the grip axis, during toothbrushing was suggested in our previous study. In this study, we describe a tooth brushing pattern classification algorithm using three-axis accelerometer and three-axis magnetic sensor. We have found that inappropriate tooth brushing pattern showed specific moving patterns. In order to trace the position and orientation of toothbrush in a mouth, we need to know absolute coordinate information of toothbrush. By applying tilt-compensated azimuth (heading) calculation algorithm, which is generally used in small telematics devices, we could find the inclination and orientation information of toothbrush. To assess the feasibility of the proposed algorithm, 8 brushing patterns were preformed by 6 individual healthy subjects. The proposed algorithm showed the detection ratio of 98%. This study showed that the proposed monitoring system was conceived to aid dental care personnel in patient education and instruction in oral hygiene regarding brushing style. PMID:18002931

  16. ANALYSIS OF METHOD FOR DETERMINING AZIMUTH OF PRINCIPAL AXIS OF INERTIA BASED ON DYNAMIC BALANCE MEASUREMENT

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun; GUAN Yingzi; QI Naiming

    2006-01-01

    The dynamic balance quality of a rotating object is an important factor to maintain the stability and accuracy for motion. The azimuth of the principal axis of inertia is a major sign of dynamic balance. A usual method is measuring moment of inertia matrix relative to some base coordinates on a rotary inertia machine so as to calculate the azimuth of principal axis of inertia. By using the measured unbalance results on the two trimmed planes on a vertical hard bearing double-plane dynamic balancing machine, the dimension and direction of couple unbalance can be found. An azimuth angle formula for the principal axis of inertia is derived and is solved by using unbalance quantities. The experiments indicate that method based on dynamic balancing measurement is proved rational and effective and has a fine precision.

  17. Traumatic Brain Injury and the Effect on the Brain-Gut Axis.

    Science.gov (United States)

    Kharrazian, Datis

    2015-08-01

    Traumatic brain injury (TBI) is a leading cause of disability worldwide. One commonly overlooked effect of TBI is the disruption of the brain-gut axis, leading to gastrointestinal dysfunction. The brain-gut axis consists of the cortical areas of the insular cortex, cingulate, and hypothalamus that have bidirectional communication with the visceral enteric nervous system through afferent and efferent projections into the pontine vagal complex and nucleus tractus solitarius. Communication with the brain also occurs through messenger signals from the gut's microbiota, involving gut peptides, cytokines, and lipopolysaccharides. Disruption of the brain-gut axis from TBI can lead to a chronic, inflammatory, vicious sequela, involving both the brain and the gastrointestinal system, with both neuroregulatory and neuroimmunological loops. PMID:26348611

  18. Hypothalamic-pituitary-adrenal axis tonus is associated with hippocampal microstructural asymmetry

    DEFF Research Database (Denmark)

    Madsen, Kathrine Skak; Jernigan, Terry L; Iversen, Pernille;

    2012-01-01

    It is well-established that prolonged high levels of cortisol have adverse effects on hippocampal neurons and glial cells. Morphometric studies linking hippocampus volume to basal HPA-axis activity, however, have yielded less consistent results. Asymmetry may also be considered, since there is gr......It is well-established that prolonged high levels of cortisol have adverse effects on hippocampal neurons and glial cells. Morphometric studies linking hippocampus volume to basal HPA-axis activity, however, have yielded less consistent results. Asymmetry may also be considered, since....... Observed associations raise a number of possibilities, among them an asymmetric role of the hippocampus on HPA-axis regulation, or conversely, that individual variations in secreted cortisol, perhaps associated with stress, may have lateralized effects on hippocampal microstructure. Our results point...

  19. Inter-relation between autonomic and HPA axis activity in children and adolescents.

    Science.gov (United States)

    Rotenberg, Sivan; McGrath, Jennifer J

    2016-05-01

    Stress research in youth typically considers either the autonomic nervous system or HPA axis. However, these systems are highly coordinated and physically interconnected. We examined whether the inter-relation between cardio-autonomic and HPA axis measures was better associated with perceived stress than their singular associations. Children and adolescents (N=201) collected saliva samples to measure cortisol (AUCAG, AUCI, maximum), wore an electrocardiogram monitor for 24h to derive heart rate variability (HRV; LF, HF, LF/HF ratio), and completed the Perceived Stress Scale. The interaction between sympathovagal modulation (LF, LF/HF ratio) and cortisol awakening response (AUCAG, AUCI, maximum) explained significantly greater variance in perceived stress than either stress system alone. Higher sympathovagal modulation combined with higher cortisol awakening response was associated with greater perceived stress. Findings suggest that the inter-relation between cardio-autonomic and HPA axis activity may advance our understanding of how stress impacts health. PMID:26835595

  20. Modelling cholesterol effects on the dynamics of the hypothalamic-pituitary-adrenal (HPA) axis.

    Science.gov (United States)

    Marković, Vladimir M; Čupić, Željko; Maćešić, Stevan; Stanojević, Ana; Vukojević, Vladana; Kolar-Anić, Ljiljana

    2016-03-01

    A mathematical model of the hypothalamic-pituitary-adrenal (HPA) axis with cholesterol as a dynamical variable was derived to investigate the effects of cholesterol, the primary precursor of all steroid hormones, on the ultradian and circadian HPA axis activity. To develop the model, the parameter space was systematically examined by stoichiometric network analysis to identify conditions for ultradian oscillations, determine conditions under which dynamic transitions, i.e. bifurcations occur and identify bifurcation types. The bifurcations were further characterized using numerical simulations. Model predictions agree well with empirical findings reported in the literature, indicating that cholesterol levels may critically affect the global dynamics of the HPA axis. The proposed model provides a base for better understanding of experimental observations, it may be used as a tool for designing experiments and offers useful insights into the characteristics of basic dynamic regulatory mechanisms that, when impaired, may lead to the development of some modern-lifestyle-associated diseases.

  1. Inter-relation between autonomic and HPA axis activity in children and adolescents.

    Science.gov (United States)

    Rotenberg, Sivan; McGrath, Jennifer J

    2016-05-01

    Stress research in youth typically considers either the autonomic nervous system or HPA axis. However, these systems are highly coordinated and physically interconnected. We examined whether the inter-relation between cardio-autonomic and HPA axis measures was better associated with perceived stress than their singular associations. Children and adolescents (N=201) collected saliva samples to measure cortisol (AUCAG, AUCI, maximum), wore an electrocardiogram monitor for 24h to derive heart rate variability (HRV; LF, HF, LF/HF ratio), and completed the Perceived Stress Scale. The interaction between sympathovagal modulation (LF, LF/HF ratio) and cortisol awakening response (AUCAG, AUCI, maximum) explained significantly greater variance in perceived stress than either stress system alone. Higher sympathovagal modulation combined with higher cortisol awakening response was associated with greater perceived stress. Findings suggest that the inter-relation between cardio-autonomic and HPA axis activity may advance our understanding of how stress impacts health.

  2. Modulation of Gut Microbiota-Brain Axis by Probiotics, Prebiotics, and Diet.

    Science.gov (United States)

    Liu, Xiaofei; Cao, Shangqing; Zhang, Xuewu

    2015-09-16

    There exists a bidirectional communication system between the gastrointestinal tract and the brain. Increasing evidence shows that gut microbiota can play a critical role in this communication; thus, the concept of a gut microbiota and brain axis is emerging. Here, we review recent findings in the relationship between intestinal microbes and brain function, such as anxiety, depression, stress, autism, learning, and memory. We highlight the advances in modulating brain development and behavior by probiotics, prebiotics, and diet through the gut microbiota-brain axis. A variety of mechanisms including immune, neural, and metabolic pathways may be involved in modulation of the gut microbiota-brain axis. We also discuss some future challenges. A deeper understanding of the relationship between the gut bacteria and their hosts is implicated in developing microbial-based therapeutic strategies for brain disorders.

  3. Forced vibration analysis of rotating structures with application to vertical axis wind turbines

    Science.gov (United States)

    Lobitz, D. W.

    Predictive methods for the dynamic analysis of wind turbine systems are important for assessing overall structural integrity and fatigue life. For the former, the identification of resonance points (spectral analysis) is of primary concern. For the latter forced vibration analysis is necessary. These analyses are complicated by the fact that, for a spinning turbine, the stress-producing deformations take place in both fixed and rotating reference systems simultaneously. As an example, the tower of a horizontal axis wind turbine (HAWT) must be analyzed in a fixed frame, and the rotor in a rotating one. Forced vibration analysis is further complicated in that accurate models need to be developed for aeroload prediction. Methods which are available for forced vibration analysis of both horizontal and vertical axis machines are identified and the method which was developed for vertical axis wind turbines is emphasized, with some comparisons of the predictions to experimental data.

  4. Evaluation of the prototype dual-axis wall attitude measurement sensor

    Science.gov (United States)

    Wong, Douglas T.

    1994-01-01

    A prototype dual-axis electrolytic tilt sensor package for angular position measurements was built and evaluated in a laboratory environment. The objective was to investigate the use of this package for making wind tunnel wall attitude measurements for the National Transonic Facility (NTF) at NASA Langley Research Center (LaRC). The instrumentation may replace an existing, more costly, and less rugged servo accelerometer package (angle-of-attack package) currently in use. The dual-axis electrolytic tilt sensor package contains two commercial electrolytic tilt sensors thermally insulated with NTF foam, all housed within a stainless steel package. The package is actively heated and maintained at 160 F using foil heating elements. The laboratory evaluation consisted of a series of tests to characterize the linearity, repeatability, cross-axis interaction, lead wire effect, step response, thermal time constant, and rectification errors. Tests revealed that the total RMS errors for the x-axis sensor is 0.084 degree, and 0.182 degree for the y-axis sensor. The RMS errors are greater than the 0.01 degree specification required for NTF wall attitude measurements. It is therefore not a viable replacement for the angle-of-attack package in the NTF application. However, with some physical modifications, it can be used as an inexpensive 5-degree range dual-axis inclinometer with overall accuracy approaching 0.01 degree under less harsh environments. Also, the data obtained from the tests can be valuable for wind tunnel applications of most types of electrolytic tilt sensors.

  5. Flexible Piezoelectric Tactile Sensor Array for Dynamic Three-Axis Force Measurement

    Science.gov (United States)

    Yu, Ping; Liu, Weiting; Gu, Chunxin; Cheng, Xiaoying; Fu, Xin

    2016-01-01

    A new flexible piezoelectric tactile sensor array based on polyvinylidene fluoride (PVDF) film is proposed for measuring three-axis dynamic contact force distribution. The array consists of six tactile units arranged as a 3 × 2 matrix with spacing 8 mm between neighbor units. In each unit, a PVDF film is sandwiched between four square-shaped upper electrodes and one square-shaped lower electrode, forming four piezoelectric capacitors. A truncated pyramid bump is located above the four piezoelectric capacitors to improve force transmission. A three-axis contact force transmitted from the top of the bump will lead to the four piezoelectric capacitors underneath undergoing different charge changes, from which the normal and shear components of the force can be calculated. A series of dynamic tests have been carried out by exerting sinusoidal forces with amplitudes ranging from 0 to 0.5 N in the x-axis, 0 to 0.5 N in the y-axis, and 0 to 1.5 N in the z-axis, separately. The tactile units show good sensitivities with 14.93, 14.92, and 6.62 pC/N in the x-, y-, and z-axes, respectively. They can work with good linearity, relatively low coupling effect, high repeatability, and acceptable frequency response in the range of 5–400 Hz to both normal and shear load. In addition, dynamic three-axis force measurement has been conducted for all of the tactile units. The average errors between the applied and calculated forces are 10.68% ± 6.84%. Furthermore, the sensor array can be easily integrated onto a curved surface, such as robotic and prosthetic hands, due to its excellent flexibility. PMID:27271631

  6. Neuromedin B stimulates the hypothalamic-pituitary-gonadal axis in male rats.

    Science.gov (United States)

    Boughton, C K; Patel, S A; Thompson, E L; Patterson, M; Curtis, A E; Amin, A; Chen, K; Ghatei, M A; Bloom, S R; Murphy, K G

    2013-11-10

    Neuromedin B (NMB) is a highly conserved bombesin-related peptide found in mammals. NMB mRNA is detected in the central nervous system (CNS) and is highly expressed in the rat hypothalamus, in particular the medial preoptic area and the arcuate nucleus. The mammalian bombesin family of receptors consists of three closely related G protein coupled receptors, BB1, BB2 and BB3. The BB1 receptor subtype has the highest affinity for NMB. NMB has well documented roles in the regulation of the thyroid axis and the stress axis in rats. However, there is little available data regarding the role of NMB in the regulation of the hypothalamic-pituitary-gonadal (HPG) axis. It is known that the NMB receptor is expressed in immortalised gonadotrophin releasing hormone (GnRH) releasing GT1-7 cells and murine forebrain GnRH neurons, and that anterior pituitary NMB-immunoreactivity is altered by changes in the sex steroid environment. The objective of these studies was thus to further investigate the effects of NMB on the HPG axis. Intracerebroventricular (ICV) administration of NMB (10 nmol) to adult male rats significantly increased plasma luteinising hormone (LH) levels 30 min after injection (plasma LH ng/ml; saline 0.69±0.07, 10 nmol NMB 1.33±0.17, P<0.01). In vitro, NMB stimulated GnRH release from hypothalamic explants from male rats and from hypothalamic GT1-7 cells. NMB had no significant effect on LH release from anterior pituitary explants from male rats, or from pituitary LβT2 cells in vitro. These results suggest a previously unreported role for NMB in the stimulation of the HPG axis via hypothalamic GnRH. Further work is now required to determine the receptor mediating the effects of NMB on the reproductive axis and the physiological role of NMB in reproduction. PMID:24120470

  7. An empirical method for calculating melt compositions produced beneath mid-ocean ridges: Application for axis and off-axis (seamounts) melting

    Science.gov (United States)

    Niu, Yaoling; Batiza, Rodey

    1991-12-01

    We present a new method for calculating the major element compositions of primary melts parental to mid-ocean ridge basalt (MORB). This model is based on the experimental data of Jaques and Green (1980), Falloon et al. (1988), and Falloon and Green (1987, 1988) which are ideal for this purpose. Our method is empirical and employs solid-liquid partition coefficients (Di) from the experiments. We empirically determine Di = ƒ(P,F) and use this to calculate melt compositions produced by decompression-induced melting along an adiabat (column melting). Results indicate that most MORBs can be generated by 10-20% partial melting at initial pressures (P0) of 12-21 kbar. Our primary MORB melts have MgO = 10-12 wt %. We fractionate these at low pressure to an MgO content of 8.0 wt % in order to interpret natural MORB liquids. This model allows us to calculate Po, Pƒ, To, Tƒ, and F for natural MORB melts. We apply the model to interpret MORB compositions and mantle upwelling patterns beneath a fast ridge (East Pacific Rise (EPR)8°N to 14°N), a slow ridge (mid-Atlantic Ridge (MAR) at 26°S), and seamounts near the EPR (Lament seamount chain). We find mantle temperature differences of up to 50°-60°C over distances of 30-50 km both across axis and along axis at the EPR. We propose that these are due to upward mantle flow in a weakly conductive (versus adiabatic) temperature gradient. We suggest that the EPR is fed by a wide (-100 km) zone of upwelling due to plate separation but has a central core of faster buoyant flow. An along-axis thermal dome between the Siqueiros transform and the 11°45' Overlapping Spreading center (OSC) may represent such an upwelling; however, in general there is a poor correlation between mantle temperature, topography, and the segmentation pattern at the EPR. For the Lament seamounts we find regular across-axis changes in Po and F suggesting that the melt zone pinches out off axis. This observation supports the idea that the EPR is fed by a

  8. An empirical method for calculating melt compositions produced beneath mid-ocean ridges: for axis and off-axis (seamounts) melting application

    Science.gov (United States)

    Batiza, Rodey

    1991-12-01

    We present a new method for calculating the major element compositions of primary melts parental to mid-ocean ridge basalt (MORB). This model is based on the experimental data of Jaques and Green (1980), Falloon et al. (1988), and Falloon and Green (1987, 1988) which are ideal for this purpose. Our method is empirical and employs solid-liquid partition coefficients (Di) from the experiments. We empirically determine Di=f(P,F) and use this to calculate melt compositions produced by decompression-induced melting along an adiabat (column melting). Results indicate that most MORBs can be generated by 10-20% partial melting at initial pressures (P0) of 12-21 kbar. Our primary MORB melts have MgO=10-12 wt %. We fractionate these at low pressure to an MgO content of 8.0 wt% in order to interpret natural MORB liquids. This model allows us to calculate Po, Pf, To, Tf, and F for natural MORB melts. We apply the model to interpret MORB compositions and mantle upwelling patterns beneath a fast ridge (East Pacific Rise (EPR) 8°N to 14°N), a slow ridge (mid-Atlantic Ridge (MAR) at 26°S), and seamounts near the EPR (Lamont seamount chain). We find mantle temperature differences of up to 50°-60°C over distances of 30-50 km both across axis and along axis at the EPR. We propose that these are due to upward mantle flow in a weakly conductive (versus adiabatic) temperature gradient. We suggest that the EPR is fed by a wide (~100 km) zone of upwelling due to plate separation but has a central core of faster buoyant flow. An along-axis thermal dome between the Siqueiros transform and the 11°45' Overlapping Spreading Center (OSC) may represent such an upwelling; however, in general there is a poor correlation between mantle temperature, topography, and the segmentation pattern at the EPR. For the Lamont seamounts we find regular across-axis changes in Po and F suggesting that the melt zone pinches out off axis. This observation supports the idea that the EPR is fed by a broad

  9. Precision Attitude Determination System (PADS) system design and analysis: Single-axis gimbal star tracker

    Science.gov (United States)

    1974-01-01

    The feasibility is evaluated of an evolutionary development for use of a single-axis gimbal star tracker from prior two-axis gimbal star tracker based system applications. Detailed evaluation of the star tracker gimbal encoder is considered. A brief system description is given including the aspects of tracker evolution and encoder evaluation. System analysis includes evaluation of star availability and mounting constraints for the geosynchronous orbit application, and a covariance simulation analysis to evaluate performance potential. Star availability and covariance analysis digital computer programs are included.

  10. Reconstruction of the Electron Density of Molecules with Single-Axis Alignment

    Energy Technology Data Exchange (ETDEWEB)

    Starodub, Dmitri

    2011-08-12

    Diffraction from the individual molecules of a molecular beam, aligned parallel to a single axis by a strong electric field or other means, has been proposed as a means of structure determination of individual molecules. As in fiber diffraction, all the information extractable is contained in a diffraction pattern from incidence of the diffracting beam normal to the molecular alignment axis. We present two methods of structure solution for this case. One is based on the iterative projection algorithms for phase retrieval applied to the coefficients of the cylindrical harmonic expansion of the molecular electron density. Another is the holographic approach utilizing presence of the strongly scattering reference atom for a specific molecule.

  11. Full off-axis red-green-blue digital holographic microscope with LED illumination.

    Science.gov (United States)

    Dubois, F; Yourassowsky, C

    2012-06-15

    We developed a new full off-axis red-green-blue (RGB) digital holographic microscope with an LED illumination. A decisive advantage of the use of LED illumination is a large image quality improvement due to its partially coherent nature. The off-axis configuration enables the fast recording of the holographic data in each spectral channel. The digital holographic refocusing and the optical phase map computation are successfully demonstrated. The multiwavelength operation provides a significant improvement of the collected information for colored samples.

  12. Uniaxial ferromagnetic film in magnetic field perpendicular to the easy axis

    Science.gov (United States)

    Korneta, W.; Pytel, Z.

    1987-08-01

    The spin model of single domain ferromagnetic film is considered. Only the nearest-neighbor interactions are taken into account. The interactions depend on distances from surfaces. The external magnetic field is applied perpendicular to the easy axis lying in the plane of the film. The thermodynamic behaviour of the model is studied near the second-order ferro-paramagnetic phase transition for the component of the magnetization in the direction of the easy axis. The molecular-field theory is used. The phase diagram and profiles of the order parameter are obtained. Different feasible investigations of the phase transition are compared.

  13. Size of Atlas and Axis in Adults with Hyphofosphatemic Rickets – a Comparative Study

    DEFF Research Database (Denmark)

    Gjørup, Hans; Sonnesen, Ane Liselotte; Beck-Nielsen, Signe;

    Title Size of atlas and axis in adults with hyphofosphatemic rickets – a comparative study. Introduction. Deviations from normal anatomy of the cervical column are frequent in some pathologic conditions (cleft-patients, OSA-patients) and in severe malocclusions. Hypophosphatemic rickets (HR...... are bony structures of cartilaginous origin. Aim It is the aim to describe the size of the atlas and axis in adults with HR in comparison with healthy controls. Material Standardized profile radiographs of 36 patients with hypophosphatemic rickets (24 females, 12 males), aged18 – 74 yrs, and 49 controls...

  14. Design and implementation of a multi-axis precision movement machine based on MAS theory

    Institute of Scientific and Technical Information of China (English)

    Li MA; Linlin CI; Genyan GE

    2009-01-01

    A model construction of a multi-agent system (MAS) and the basic function of the agent are described.The precision control method using the multi-CPU of a programmable logic controller (PLC) is introduced,and a distributed method using multiple CPUs to control different motion machines is given.The test results indicate that in industrial control fields,the combination of using the credible PLC to control the motion machine and multi-CPU task distributing methods can solve multi-axis machine linkage and implication,providing a more credible method for multi-axis motion units.

  15. A Singular Limit Problem for Rotating Capillary Fluids with Variable Rotation Axis

    Science.gov (United States)

    Fanelli, Francesco

    2016-04-01

    In the present paper we study a singular perturbation problem for a Navier-Stokes-Korteweg model with Coriolis force. Namely, we perform the incompressible and fast rotation asymptotics simultaneously, while we keep the capillarity coefficient constant in order to capture surface tension effects in the limit. We consider here the case of variable rotation axis: we prove the convergence to a linear parabolic-type equation with variable coefficients. The proof of the result relies on compensated compactness arguments. Besides, we look for minimal regularity assumptions on the variations of the axis.

  16. Six-axis force–torque sensor with a large range for biomechanical applications

    International Nuclear Information System (INIS)

    A silicon six-axis force–torque sensor is designed and realized to be used for measurement of the power transfer between the human body and the environment. Capacitive read-out is used to detect all axial force components and all torque components simultaneously. Small electrode gaps in combination with mechanical amplification by the sensor structure result in a high sensitivity. The miniature sensor has a wide force range of up to 50 N in normal direction, 10 N in shear direction and 25 N mm of maximum torque around each axis. (paper)

  17. Nondispersion polaritons on symmetrically oriented surfaces of two-axis crystals

    International Nuclear Information System (INIS)

    One derived system of dispersion equations describing surface polaritons in optic two-axis crystals on surfaces parallel to symmetry planes of ε permittivity tensor. One analyzes ranges of occurrence, value and orientation of sectors of propagation directions of nondispersion surface polaritons occurring at positive values of ε tensor components. For slightly anisotropic crystals one determined three noncrossing values of dielectric anisotropy parameters where nondispersion polariton may occur. One traced evolution of configuration of optic axis at variation of anisotropy parameters within ranges of occurrence of polaritons

  18. A simplified version of the "Axis of Evil Theorem" for distinct points

    OpenAIRE

    Ceria, Michela

    2012-01-01

    Given a finite set $\\mathbf{X}$ of distinct points, Marinari-Mora's 'Axis of Evil Theorem' states that a combinatorial algorithm and interpolation enable to find a 'linear' factorization for a lexicographical minimal Groebner basis $\\mathcal{G}(I(\\mathbf{X}))$ of the zerodimensional radical ideal $I(\\mathbf{X})$. In this work we provide such algorithm, showing that it ends in a finite number of steps and that it actually provides the correct result. The 'Axis of Evil' algorithm takes as input...

  19. Electron gun with off-axis beam injection for a race-track microtron

    International Nuclear Information System (INIS)

    A miniature 12 MeV race-track microtron for medical applications is under construction at the Technical University of Catalonia in collaboration with several Spanish centers and companies and the Skobeltsyn Institute of Nuclear Physics of the Moscow State University. As a source of electrons a compact 3D on-axis electron gun with an off-axis cathode has been designed to allow a direct and efficient injection into the accelerating structure. Its prototype has been built and successfully tested. Results of the electron gun design simulations and of the prototype performance are herein described.

  20. On the estimation of the magnetic easy axis in pipeline steels using magnetic Barkhausen noise

    Science.gov (United States)

    Martínez-Ortiz, P.; Pérez-Benitez, J. A.; Espina-Hernández, J. H.; Caleyo, F.; Hallen, J. M.

    2015-01-01

    A method for determination of the magnetic easy axis of the Roll Magnetic Anisotropy in API-5L steels is proposed. The method is based on the fact that the angular dependence of the energy corresponding to the main peak of the Magnetic Barkhausen signal presents uniaxial anisotropy with its easy axis parallel to the rolling direction, independently of the angular dependence of the magnetocrystalline energy in the materials. The proposal is also justified based on the analysis of the influence of microstructural changes, produced by hot-rolling on the domain wall dynamics.

  1. FSH and TSH in the Regulation of Bone Mass: The Pituitary/Immune/Bone Axis

    OpenAIRE

    Graziana Colaianni; Concetta Cuscito; Silvia Colucci

    2013-01-01

    Recent evidences have highlighted that the pituitary hormones have profound effects on bone, so that the pituitary-bone axis is now becoming an important issue in the skeletal biology. Here, we discuss the topical evidence about the dysfunction of the pituitary-bone axis that leads to osteoporotic bone loss. We will explore the context of FSH and TSH hormones arguing their direct or indirect role in bone loss. In addition, we will focus on the knowledge that both FSH and TSH have influence on...

  2. Optical Design for the Off-axis Reflective Optics with Wide Field

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Reflective optics with wide field of view has been applied more and more widely in EUVL or space optics, and also plays an important role in promoting scientific and technological research. Among the reflective optics, the off-axis reflective optics is the most hopeful solution to the ever-highest demands of these applications. This paper gives the requirements of both the above mentioned applications and the similarities and differences between these two kinds of optical systems. Finally, a design example of off-axis reflective optics with wide field of view is presented and described.

  3. Off-Axis Astigmatic Gaussian Beam Combination Beyond the Paraxial Approximation

    Institute of Scientific and Technical Information of China (English)

    GAO Zeng-Hui; L(U) Bai-Da

    2007-01-01

    Taking the off-axis astigmatic Gaussian beam combination as an example, the beam-combination concept is extended to the nonparaxial regime. The closed-form propagation expressions for coherent and incoherent combinations of nonparaxial off-axis astigmatic Gaussian beams with rectangular geometry are derived and illustrated with numerical examples. It is shown that the intensity distributions of the resulting beam depend on the combination scheme and beam parameters in general, and in the paraxial approximation (i.e., for the small f-parameter)our results reduce to the paraxial ones.

  4. Cognition and HPA axis reactivity in mildly to moderately depressed outpatients. A case-control study

    DEFF Research Database (Denmark)

    Krogh, Jesper; Videbech, Poul; Renvillard, Signe Groth;

    2012-01-01

    outpatients (n =¿83, ICD-10) were group-matched to healthy controls (n =¿33), and tested on a number of cognitive domains. Salivary samples were collected at awakening, 30 min later and at 22:00 h. At 23:00 h, the participants ingested 1.0 mg of dexamethasone, and three saliva samples were collected......Background: Patients with depression display neurobiological changes of the hypothalamic-pituitary axis as well as cognitive disturbances. Aims: To assess any association between hypothalamus-pituitary-adrenal (HPA) axis reactivity and memory-related cognitive functions. Methods: Depressed...

  5. Orbital Angular Momentum in Noncollinear Second Harmonic Generation by off-axis vortex beams

    CERN Document Server

    Bovino, Fabio Antonio; Giardina, Maurizio; Sibilia, Concita

    2011-01-01

    We experimentally study the behavior of orbital angular momentum (OAM) of light in a noncollinear second harmonic generation (SHG) process. The experiment is performed by using a type I BBO crystal under phase matching conditions with femtosecond pumping fields at 830 nm. Two specular off-axis vortex beams carrying fractional orbital angular momentum at the fundamental frequency (FF) are used. We analyze the behavior of the OAM of the SH signal when the optical vortex of each input field at the FF is displaced from the beam's axis. We obtain different spatial configurations of the SH field, always carrying the same zero angular momentum.

  6. Feasibility study on 3 axis magnetic sensor for flux leakage method

    Science.gov (United States)

    Sasamoto, Akira

    2014-04-01

    Most of NDT system by magnetic field sensing has employed coil or semiconductor as sensor which has one axis sensitivity. Recent development of semiconductor technology can makes a chip that enable us to measure 3 axis magnetic field in a 1mm square. This vector information is expected to show a new insight in NDT testing. This presentation will show a basic experimental feasibility study for application of magnetic sensor to flux leakage and eddy current testing method by using a sensing system with the chip.

  7. Research on the unsteady hydrodynamic characteristics of vertical axis tidal turbine

    Science.gov (United States)

    Zhang, Xue-wei; Zhang, Liang; Wang, Feng; Zhao, Dong-ya; Pang, Cheng-yan

    2014-03-01

    The unsteady hydrodynamic characteristics of vertical axis tidal turbine are investigated by numerical simulation based on viscous CFD method. The starting mechanism of the turbine is revealed through analyzing the interaction of its motion and dynamics during starting process. The operating hydrodynamic characteristics of the turbine in wave-current condition are also explored by combining with the linear wave theory. According to possible magnification of the cyclic loads in the maximum power tracking control of vertical axis turbine, a novel torque control strategy is put forward, which can improve the structural characteristics significantly without effecting energy efficiency.

  8. OPTIMAL DESIGN OF A 6-AXIS FORCE TRANSDUCER BASED ON STEWART PLATFORM RELATED TO SENSITIVITY ISOTROPY

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The design method of a 6-axis force robot's transducer based on the Stewart platform is detailed.For this purpose, the sensitivity isotropy evaluation criteria of the transducer are defined, and by the aid of computer, the relationships between the criteria and the parameters of all the transducers based on the Stewart platform are investigated within the geometric model of the solution space, which can provide the theoretical background for the optimal construction design of the 6-axis force transducer related to the sensitivity isotropy.

  9. Activation of the hypothalamic-pituitary-adrenal stress axis induces cellular oxidative stress

    Directory of Open Access Journals (Sweden)

    Jereme G. Spiers

    2015-01-01

    Full Text Available Glucocorticoids released from the adrenal gland in response to stress-induced activation of the hypothalamic-pituitary-adrenal (HPA axis induce activity in the cellular reduction-oxidation (redox system. The redox system is a ubiquitous chemical mechanism allowing the transfer of electrons between donor/acceptors and target molecules during oxidative phosphorylation while simultaneously maintaining the overall cellular environment in a reduced state. The objective of this review is to present an overview of the current literature discussing the link between HPA axis-derived glucocorticoids and increased oxidative stress, particularly focussing on the redox changes observed in the hippocampus following glucocorticoid exposure.

  10. Static/dynamic Analysis and Optimization of Z-axis Stand of PCB CNC Drilling Machine*

    Directory of Open Access Journals (Sweden)

    Zhou Yanjun

    2016-01-01

    Full Text Available The finite element analysis is used for the static and dynamic analysis of the Z axis brace of PCB CNC drilling machine. With its results of maximum displacement deformation and von Mises stress and modal frequency, the defect of original design was found out. On such bases, a variety of optimization scheme is put forward and the best size of the Z axis brace is obtained by the performance comparison of the schemes. This method offers bases for the design and renovation of other machine tool components.

  11. Innovative Design of Vertical Axis Wind Turbine:a poster presented at DAMAS 2013 conference

    OpenAIRE

    Chougule, Prasad

    2013-01-01

    The wind turbines can be classified as: i) Horizontal axis windturbines (HAWT), and ii) Vertical axis wind turbines (VAWT). TheHAWT is fully developed and the size is growing higher. Whereas,the VAWT is not developed because of the less efficiency andvibration issues of big structure. However, it is well known that theVAWT is advantages over a HAWT in terms of a cost and thesimplicity (Paraschivoiu 2002). In this PhD project a simple bladedesign is incorporated by using the two-element airofo...

  12. Atomic resolution electrostatic potential mapping of graphene sheets by off-axis electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, David, E-mail: david.cooper@cea.fr [University Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054, Grenoble (France); Pan, Cheng-Ta; Haigh, Sarah [School of Materials, The University of Manchester, Manchester M13 9PL (United Kingdom)

    2014-06-21

    Off-axis electron holography has been performed at atomic resolution with the microscope operated at 80 kV to provide electrostatic potential maps from single, double, and triple layer graphene. These electron holograms have been reconstructed in order to obtain information about atomically resolved and mean inner potentials. We propose that off-axis electron holography can now be used to measure the electrical properties in a range of two-dimensional semiconductor materials and three dimensional devices comprising stacked layers of films to provide important information about their electrical properties.

  13. Research on the Unsteady Hydrodynamic Characteristics of Vertical Axis Tidal Turbine

    Institute of Scientific and Technical Information of China (English)

    张学伟; 张亮; 王峰; 赵东亚; 庞程燕

    2014-01-01

    The unsteady hydrodynamic characteristics of vertical axis tidal turbine are investigated by numerical simulation based on viscous CFD method. The starting mechanism of the turbine is revealed through analyzing the interaction of its motion and dynamics during starting process. The operating hydrodynamic characteristics of the turbine in wave-current condition are also explored by combining with the linear wave theory. According to possible magnification of the cyclic loads in the maximum power tracking control of vertical axis turbine, a novel torque control strategy is put forward, which can improve the structural characteristics significantly without effecting energy efficiency.

  14. Using a double-frequency RF system to facilitate on-axis beam accumulation in a storage ring

    CERN Document Server

    Jiang, B C; Tian, S Q; Zhang, M Z; Zhang, Q L

    2016-01-01

    An on-axis injection scheme using a double-frequency RF system in a storage ring with small dynamic aperture is proposed. By altering RF voltages, empty RF buckets can be created which will be used for on-axis injection. After bunches are injected, a reverse RF voltage altering process is performed and the injected bunches can be longitudinally dumped to the main RF buckets. The scheme allows reaping the advantages of the on-axis injection while still performing accumulation.

  15. Genetic and epigenetic studies of diabetes and diabetic nephropathy with focus on the IGF-IGFBP axis

    OpenAIRE

    Gu, Tianwei

    2014-01-01

    Diabetes and diabetic nephropathy (DN) are complex diseases reflecting a complex interplay between genetic and non-genetic factors. The insulin-like growth factor (IGF) - IGF binding protein (IGFBP) axis plays an important role in the development of diabetes and DN. Recent reports have demonstrated that genetic polymorphisms in this axis are associated with diabetes and DN. However, the information of epigenetic study is very limited. In this study, we selected four genes from this axis inclu...

  16. Angiogenic, hyperpermeability and vasodilator network in utero-placental units along pregnancy in the guinea-pig (Cavia porcellus

    Directory of Open Access Journals (Sweden)

    Chacón Cecilia

    2008-03-01

    Full Text Available Abstract Background The angiogenic and invasive properties of the cytotrophoblast are crucial to provide an adequate area for feto-maternal exchange. The present study aimed at identifying the localization of interrelated angiogenic, hyperpermeability and vasodilator factors in the feto-maternal interface in pregnant guinea-pigs. Methods Utero-placental units were collected from early to term pregnancy. VEGF, Flt-1, KDR, B2R and eNOS were analyzed by immunohistochemistry, and the intensity of the signals in placenta and syncytial streamers was digitally analysed. Flt1 and eNOS content of placental homogenates was determined by western blotting. Statistical analysis used one-way analysis of variance and Tukey's Multiple Comparison post-hoc test. Results In the subplacenta, placental interlobium and labyrinth VEGF, Flt-1, KDR, B2R and eNOS were expressed in all stages of pregnancy. Syncytial streamers in all stages of gestation, and cytotrophoblasts surrounding myometrial arteries in early and mid pregnancy – and replacing the smooth muscle at term – displayed immunoreactivity for VEGF, Flt-1, KDR, eNOS and B2R. In partly disrupted mesometrial arteries in late pregnancy cytotrophoblasts and endothelial cells expressed VEGF, Flt-1, KDR, B2R and eNOS. Sections incubated in absence of the first antibody, or in presence of rabbit IgG fraction and mouse IgG serum, yielded no staining. According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016, and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026, while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy. In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027, while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011; VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations. Western blots for

  17. INTERFERENCE-FREE TOOL POSTURE GENERATION FOR 5-AXIS NC MILLING FREE-FORM SURFACES WITH CYLINDRICAL MILL

    Institute of Scientific and Technical Information of China (English)

    Chen Liping; Chen Yan; Hu Dejin

    2004-01-01

    The 5-axis NC machining offers the potential of efficient and accurate machining. However, the present CAM system for 5-axis control is still an unsolved problem due to interference between tool and surrounding objects. A new method is presented. There are two steps in this procedure. First, it detects the interference by calculating the shortest distance between the tool-axis and the surrounding surfaces. Then upon the maximum gouging, the interference-free tool posture for 5-axis NC cylindrical milling free-form surfaces is obtained by adjusting tool. The validity of the proposed method has been confirmed by machining an impeller.

  18. Star tracker axis-to-sunlit earth horizon angle constraint evaluations for rendezvous operations

    Science.gov (United States)

    Hutchison, W. L.

    1975-01-01

    The results are presented of a study initiated to evaluate the star tracker axis-to-sunlit earth horizon angle constraint with respect to limitations imposed on the passive target rendezvous capability. The data presented include considerations for dispersions and sensor pointing capabilities and generalizations with respect to the uncertainties associated with the angle constraint available in practice.

  19. Rotation Angle for the Optimum Tracking of One-Axis Trackers

    Energy Technology Data Exchange (ETDEWEB)

    Marion, W. F.; Dobos, A. P.

    2013-07-01

    An equation for the rotation angle for optimum tracking of one-axis trackers is derived along with equations giving the relationships between the rotation angle and the surface tilt and azimuth angles. These equations are useful for improved modeling of the solar radiation available to a collector with tracking constraints and for determining the appropriate motor revolutions for optimum tracking.

  20. Role of the insulin-like growth factor 1 axis and visceral adiposity in oesophageal adenocarcinoma.

    LENUS (Irish Health Repository)

    Donohoe, C L

    2012-03-01

    Epidemiological studies have linked obesity with many cancers. The insulin-like growth factor (IGF) 1 axis may be an important mediator in obesity-associated cancer. This study examined the relationship between IGF-1 and its receptor (IGF-1R) in oesophageal adenocarcinoma, a cancer strongly linked to obesity.

  1. Traveltime approximations for inhomogeneous transversely isotropic media with a horizontal symmetry axis

    KAUST Repository

    Alkhalifah, Tariq Ali

    2012-04-30

    Traveltime information is crucial for parameter estimation, especially if the medium is described by a set of anisotropy parameters. We can efficiently estimate these parameters if we are able to relate them analytically to traveltimes, which is generally hard to do in inhomogeneous media. I develop traveltime approximations for transversely isotropic media with a horizontal symmetry axis (HTI) as simplified and even linear functions of the anisotropy parameters. This is accomplished by perturbing the solution of the HTI eikonal equation with respect to the anellipticity parameter, η and the azimuth of the symmetry axis (typically associated with the fracture direction) from a generally inhomogeneous, elliptically anisotropic background medium. Such a perturbation is convenient since the elliptically anisotropic information might be obtained from well velocities in HTI media. Thus, we scan for only η and the symmetry-axis azimuth. The resulting approximations can provide a reasonably accurate analytical description of the traveltime in a homogenous background compared to other published moveout equations. They also help extend the inhomogenous background isotropic or elliptically anisotropic models to an HTI one with a smoothly variable η and symmetry-axis azimuth. © 2012 European Association of Geoscientists & Engineers.

  2. Hypothalamic-pituitary-adrenal axis reactivity to social stress and adolescent cannabis use : the TRAILS study

    NARCIS (Netherlands)

    van Leeuwen, Andrea Prince; Creemers, Hanneke E.; Greaves-Lord, Kirstin; Verhulst, Frank C.; Ormel, Johan; Huizink, Anja C.

    2011-01-01

    Aims To investigate the relationship of life-time and repeated cannabis use with hypothalamic-pituitary-adrenal (HPA) axis reactivity to social stress in a general population sample of adolescents. Design Adolescents who reported life-time or repeated cannabis use, life-time or repeated tobacco use

  3. CT analysis of the axis for transarticular screw fixation of rheumatoid atlantoaxial instability

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Sung Soo; Lee, Chong Suh; Kang, Chang Seok [Sungkyunkwan University School of Medicine, Department of Orthopedic Surgery, Samsung Medical Center, Seoul (Korea); Chung, Hye Won [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea)

    2006-09-15

    To investigate the morphological characteristics of the axis of rheumatoid arthritis (RA) patients with atlantoaxial instability and to determine, by means of sagittal reconstructed computed tomography (CT), the suitability for atlantoaxial transarticular screw fixation. Twenty-seven patients, who had undergone reconstructed cervical spine CT scanning preoperatively and posterior atlantoaxial arthrodesis for atlantoaxial instability, were identified from a database for inclusion in this study. The isthmus height and internal height of the lateral mass of the axis were measured using digital imaging software. The mean isthmus height and internal height of the lateral mass of the axis in RA patients (n=14) were significantly lower than in non-RA patients (n=13) (P<0.01). A high-riding vertebral artery (VA) was present in 54% (15 joints, 9 patients) of the 28 atlantoaxial joints in the RA group and in 12% (3 joints, 2 patients) of the 26 atlantoaxial joints in the non-RA group (P<0.01). In RA patients, the axis showed more extensive thinning of the isthmus and lateral mass than in non-RA patients. A precise preoperative evaluation of screw trajectory using reconstruction CT imaging may be useful in atlantoaxial transarticular fixation, particularly for RA patients with atlantoaxial instability. (orig.)

  4. Helicopter terminal approach using differential GPS with vertical-axis enhancement

    Science.gov (United States)

    Edwards, F. G.; Paielli, R. A.; Hegarty, D. M.

    1987-01-01

    The NAVSTAR Global Positioning System (GPS) in differential mode (DGPS) has been shown to be least accurate in the vertical axis. The vertical axis also has the most stringent accuracy requirements for aircraft precision approach and landing. A series of flight tests were conducted to evaluate a concept for improving the DGPS vertical axis navigation performance. These tests incorporated augmentation sensors to aid the DGPS navigation solution during terminal approach operations. A GPS receiver was installed on board a NASA helicopter and interfaced with a real-time digital computer system. A reconfigurable navigation filter programmed in the digital computer provided an augmented DGPS solution, with selectable inputs from a low-cost vertical accelerometer, a barometric altimeter, and the aircraft attitude gyros. The reference aircraft position was determined by a laser tracker. Extensive post-test analysis was done to optimize the filter performance during the terminal approach operation. Test results show that baro-altimeter aiding can significantly improve vertical axis performance. Follow-on tests are planned for the optimized configurations.

  5. Hybrid version of the tilted axis cranking model and its application to 128Ba

    International Nuclear Information System (INIS)

    A hybrid version the deformed nuclear potential is suggested, which combines a spherical Woods-Saxon potential with a deformed Nilsson potential. It removes the problems of the conventional Nilsson potential in the mass 130 region. Based on the hybrid potential, tilted axis cranking calculations are carried out for the magnetic dipole band in 128Ba. (c) 2000 The American Physical Society

  6. Extremely Soft X-ray Flash as the indicator of off-axis orphan GRB afterglow

    CERN Document Server

    Urata, Yuji; Yamazaki, Ryo; Sakamoto, Takanori

    2015-01-01

    We verified the off-axis jet model of X-ray flashes (XRFs) and examined a discovery of off-axis orphan gamma-ray burst (GRBs) afterglows. The XRF sample was selected on the basis of the following three factors: (1) a constraint on the lower peak energy of the prompt spectrum $E^{src}_{obs}$, (2) redshift measurements, and (3) multi-color observations of an earlier (or brightening) phase. XRF020903 was the only sample selected basis of these criteria. A complete optical multi-color afterglow light curve of XRF020903 obtained from archived data and photometric results in literature showed an achromatic brightening around 0.7 days. An off-axis jet model with a large observing angle (0.21 rad, which is twice the jet opening half-angle, $\\theta_{jet}$) can naturally describe the achromatic brightening and the prompt X-ray spectral properties. This result indicates the existence of off-axis orphan GRB afterglow light curves. Events with a larger viewing angle ($>\\sim2\\theta_{jet}$) could be discovered using an 8-m ...

  7. Handheld multispectral dual-axis confocal microscope for cervical cancer screening

    Science.gov (United States)

    Sarapukdee, Pongsak; Rattanavarin, Santi; Jarujareet, Ungkarn; Khemthongcharoen, Numfon; Jolivot, Romuald; Jung, Il Woong; López, Daniel; Mandella, Michael J.; Piyawattanametha, Wibool

    2013-03-01

    Our work demonstrates a MEMS based handheld dual-axis confocal microscope for cervical cancer screening. Imaging demonstration is performed with plant and animal tissue biopsies. The data is collected and displayed in real time with 2-5 Hz frame rates.

  8. Use of two-axis joystick for control of externally powered shoulder disarticulation prostheses

    Directory of Open Access Journals (Sweden)

    Robert D. Lipschutz, BSME, CP

    2011-07-01

    Full Text Available We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses with a two-axis joystick. We tested 10 subjects with intact shoulders and arms to determine the average amount of shoulder motion and force available to control an electronic input device. We then applied this information to two different input strategies to examine their effectiveness: (1 a traditional rocker potentiometer and a pair of force-sensing resistors and (2 a two-axis joystick. Three nondisabled subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental externally powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, because it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses with a two-axis joystick.

  9. Design of rotor blade for vertical axis wind turbine using double aerofoil

    Energy Technology Data Exchange (ETDEWEB)

    Chougule, P.D.; Ratkovich, N.; Kirkegaard, P.H.; Nielsen, Soeren R.K. [Aalborg Univ.. Dept. of Civil Engineering, Aalborg (Denmark)

    2012-07-01

    Nowadays, small vertical axis wind turbines are receiving more attention compared to horizontal wind turbines due to their suitability in urban use,because they generate less noise, have bird free turbines and lower cost. There are few vertical axis wind turbines design with good power curve. However, the efficiency of power extraction has not been improved. Therefore, an attempt has been made to utilize high lift technology in practice for vertical axis wind turbines in order to improve power efficiency. High lift is obtained by double aerofoil elements mainly used in aeroplane wing design. In this current work, two aerofoils are used to design a rotor blade for a vertical axis wind turbine to improve the power efficiency on the rotor. Double aerofoil blade design consists of a main aerofoil and a slat aerofoil. The parameters related to position and orientation of the slat aerofoil with respect to the main aerofoil defines the high lift. Orientation of slat aerofoil is a parameter of investigation in this paper. Computational fluid dynamics (CFD) have been used to obtain the aerodynamic characteristics of double aerofoil. The CFD simulations were carried out using Star CCM+ v7.04 (CD-adapco, UK) software. Aerofoils used in this work are selected from standard aerofoil shapes. (Author)

  10. Angle calculations for a z-axis/(2S+2D) hybrid diffractometer

    DEFF Research Database (Denmark)

    Bunk, Oliver; Nielsen, Martin Meedom

    2004-01-01

    calculations are presented for a new 'hybrid' diffractometer consisting of a base instrument that can be combined with two different detector arms. With one of the detector arms, the instrument is a standard z-axis diffractometer as commonly used in surface studies. The other detector arm is designed...

  11. Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lu Zenghai; Kasaragod, Deepa K; Matcher, Stephen J, E-mail: z.lu@sheffield.ac.uk, E-mail: s.j.matcher@sheffield.ac.uk [Department of Materials Science and Engineering, Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ (United Kingdom)

    2011-02-21

    We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincare sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.

  12. MOTION ERROR ESTIMATION OF5-AXIS MACHINING CENTER USING DBB METHOD

    Institute of Scientific and Technical Information of China (English)

    CHEN Huawei; ZHANG Dawei; TIAN Yanling; ICHIRO Hagiwara

    2006-01-01

    In order to estimate the motion errors of 5-axis machine center, the double ball bar (DBB)method is adopted to realize the diagnosis procedure. The motion error sources of rotary axes in 5-axis machining center comprise of the alignment error of rotary axes and the angular error due to various factors, e.g. the inclination of rotary axes. From sensitive viewpoints, each motion error is possible to have a particular sensitive direction in which deviation of DBB error trace arises from only some specific error sources. The model of the DBB error trace is established according to the spatial geometry theory. Accordingly, the sensitive direction of each motion error source is made clear through numerical simulation, which is used as the reference patterns for rotational error estimation.The estimation method is proposed to easily estimate the motion error sources of rotary axes in quantitative manner. To verify the proposed DBB method for rotational error estimation, the experimental tests are carried out on a 5-axis machining center M-400 (MORISEIKI). The effect of the mismatch of the DBB is also studied to guarantee the estimation accuracy. From the experimental data, it is noted that the proposed estimation method for 5-axis machining center is feasible and effective.

  13. Hydrothermal synthesis, off-axis electron holography and magnetic properties of Fe3O4 nanoparticles

    DEFF Research Database (Denmark)

    Almeida, Trevor P.; Muxworthy, Adrian R.; Williams, Wyn;

    2014-01-01

    The hydrothermal synthesis of Fe3O4 nanoparticles (NPs) (<50 nm) from mixed FeCl3 / FeCl2 precursor solution at pH ~ 12 has been confirmed using complementary characterisation techniques of transmission electron microscopy and X-ray diffractometry. Off-axis electron holography allowed for visuali......The hydrothermal synthesis of Fe3O4 nanoparticles (NPs) (

  14. Compressive damage mechanism of GFRP composites under off-axis loading: Experimental and numerical investigations

    DEFF Research Database (Denmark)

    Zhou, H.W.; Li, H.Y.; Gui, L.L.;

    2013-01-01

    Experimental and computational studies of the microscale mechanisms of damage formation and evolution in unidirectional glass fiber reinforced polymer composites (GFRP) under axial and off-axis compressive loading are carried out. A series of compressive testing of the composites with different a...

  15. Impact of Sleep and Its Disturbances on Hypothalamo-Pituitary-Adrenal Axis Activity

    Directory of Open Access Journals (Sweden)

    Marcella Balbo

    2010-01-01

    Full Text Available The daily rhythm of cortisol secretion is relatively stable and primarily under the influence of the circadian clock. Nevertheless, several other factors affect hypothalamo-pituitary-adrenal (HPA axis activity. Sleep has modest but clearly detectable modulatory effects on HPA axis activity. Sleep onset exerts an inhibitory effect on cortisol secretion while awakenings and sleep offset are accompanied by cortisol stimulation. During waking, an association between cortisol secretory bursts and indices of central arousal has also been detected. Abrupt shifts of the sleep period induce a profound disruption in the daily cortisol rhythm, while sleep deprivation and/or reduced sleep quality seem to result in a modest but functionally important activation of the axis. HPA hyperactivity is clearly associated with metabolic, cognitive and psychiatric disorders and could be involved in the well-documented associations between sleep disturbances and the risk of obesity, diabetes and cognitive dysfunction. Several clinical syndromes, such as insomnia, depression, Cushing's syndrome, sleep disordered breathing (SDB display HPA hyperactivity, disturbed sleep, psychiatric and metabolic impairments. Further research to delineate the functional links between sleep and HPA axis activity is needed to fully understand the pathophysiology of these syndromes and to develop adequate strategies of prevention and treatment.

  16. Use of two-axis joystick for control of externally powered shoulder disarticulation prostheses.

    Science.gov (United States)

    Lipschutz, Robert D; Lock, Blair; Sensinger, Jonathon; Schultz, Aimee E; Kuiken, Todd A

    2011-01-01

    We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses with a two-axis joystick. We tested 10 subjects with intact shoulders and arms to determine the average amount of shoulder motion and force available to control an electronic input device. We then applied this information to two different input strategies to examine their effectiveness: (1) a traditional rocker potentiometer and a pair of force-sensing resistors and (2) a two-axis joystick. Three nondisabled subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental externally powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, because it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis) could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses with a two-axis joystick.

  17. Use of a Two-Axis Joystick for Control of Externally Powered, Shoulder Disarticulation Prostheses

    Science.gov (United States)

    Lipschutz, Robert D.; Lock, Blair; Sensinger, Jonathon; Schultz, Aimee E.; Kuiken, Todd A.

    2015-01-01

    We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses using a two-axis joystick. Ten subjects with intact shoulders and arms were tested to determine the average amount of shoulder motion and force available for control of an electronic input device. This information was then applied to two different input strategies in order to examine their effectiveness: (1) a traditional strategy implemented with a rocker potentiometer and a pair of force-sensing resistors (FSRs), and (2) a strategy implemented with a two-axis joystick. Three able-bodied subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation, and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, as it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis) could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses via a two-axis joystick. PMID:21938653

  18. Activation of the Hypothalamic-Pituitary-Adrenal (HPA) Axis Following Extended Exposure to Atrazine (ATR)###

    Science.gov (United States)

    While it is known that adrenal steroids impact reproduction and a variety of other physiological and behavioral functions, disruption of the HPA-axis is not typically considered in toxicological studies. Here we characterize changes in basal corticosterone (CORT) and progesterone...

  19. Activation of the Hypothalamic-Pituitary-Adrenal (HPA) Axis Following Extended Exposure to Atrazine (ATR)

    Science.gov (United States)

    While it is known that adrenal steroids impact reproduction and a variety of other physiological and behavioral fimctions, disruption of the HPA-axis is not typically considered in toxicological studies. Here we characterize changes in basal corticosterone (CORT) and progesterone...

  20. Polymorphisms in the insulin-like growth factor axis are associated with gastrointestinal cancer

    NARCIS (Netherlands)

    Ong, J.; Salomon, J.; Morsche, R.H.M. te; Roelofs, H.M.J.; Witteman, B.J.; Dura, P.; Lacko, M.; Peters, W.H.M.

    2014-01-01

    INTRODUCTION: Numerous factors influence the development of gastrointestinal (GI) cancer. The insulin-like growth factor (IGF) axis plays a role in embryonic and postnatal growth and tissue repair. Elevated levels of IGFs, low levels of IGF binding proteins (IGFBPs) and over-expression of IGF recept

  1. Analysis of soybean embryonic axis proteins by two-dimensional gel electrophoresis and mass spectrometry

    Science.gov (United States)

    A proteomic approach based on two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) for protein separation and subsequent mass spectrometry (MS) for protein identification was applied to establish a proteomic reference map for the soybean embryonic axis. Proteins were extracted from dissecte...

  2. A new z-axis resonant micro-accelerometer based on electrostatic stiffness.

    Science.gov (United States)

    Yang, Bo; Wang, Xingjun; Dai, Bo; Liu, Xiaojun

    2015-01-05

    Presented in the paper is the design, the simulation, the fabrication and the experiment of a new z-axis resonant accelerometer based on the electrostatic stiffness. The new z-axis resonant micro-accelerometer, which consists of a torsional accelerometer and two plane resonators, decouples the sensing movement of the accelerometer from the oscillation of the plane resonators by electrostatic stiffness, which will improve the performance. The new structure and the sensitive theory of the acceleration are illuminated, and the equation of the scale factor is deduced under ideal conditions firstly. The Ansys simulation is implemented to verify the basic principle of the torsional accelerometer and the plane resonator individually. The structure simulation results prove that the effective frequency of the torsional accelerometer and the plane resonator are 0.66 kHz and 13.3 kHz, respectively. Then, the new structure is fabricated by the standard three-mask deep dry silicon on glass (DDSOG) process and encapsulated by parallel seam welding. Finally, the detecting and control circuits are designed to achieve the closed-loop self-oscillation, to trace the natural frequency of resonator and to measure the system frequency. Experimental results show that the new z-axis resonant accelerometer has a scale factor of 31.65 Hz/g, a bias stability of 727 µg and a dynamic range of over 10 g, which proves that the new z-axis resonant micro-accelerometer is practicable.

  3. A New Z-axis Resonant Micro-Accelerometer Based on Electrostatic Stiffness

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2015-01-01

    Full Text Available Presented in the paper is the design, the simulation, the fabrication and the experiment of a new z-axis resonant accelerometer based on the electrostatic stiffness. The new z-axis resonant micro-accelerometer, which consists of a torsional accelerometer and two plane resonators, decouples the sensing movement of the accelerometer from the oscillation of the plane resonators by electrostatic stiffness, which will improve the performance. The new structure and the sensitive theory of the acceleration are illuminated, and the equation of the scale factor is deduced under ideal conditions firstly. The Ansys simulation is implemented to verify the basic principle of the torsional accelerometer and the plane resonator individually. The structure simulation results prove that the effective frequency of the torsional accelerometer and the plane resonator are 0.66 kHz and 13.3 kHz, respectively. Then, the new structure is fabricated by the standard three-mask deep dry silicon on glass (DDSOG process and encapsulated by parallel seam welding. Finally, the detecting and control circuits are designed to achieve the closed-loop self-oscillation, to trace the natural frequency of resonator and to measure the system frequency. Experimental results show that the new z-axis resonant accelerometer has a scale factor of 31.65 Hz/g, a bias stability of 727 µg and a dynamic range of over 10 g, which proves that the new z-axis resonant micro-accelerometer is practicable.

  4. Off-Axis Gaussian Beams with Random Displacement in Atmospheric Turbulence

    Directory of Open Access Journals (Sweden)

    Yahya Baykal

    2006-10-01

    Full Text Available Our recent work in which we study the propagation of the general Hermite-sinusoidal-Gaussian laser beams in wireless broadband access telecommunication systems is elaborated in this paper to cover the special case of an off-axis Gaussian beam. We mainly investigate the propagation characteristics in atmospheric turbulence of an off-axis Gaussian beam possessing Gaussian distributed random displacement parameters. Our interest is to search for different types of laser beams that will improve the performance of a wireless broadband access system when atmospheric turbulence is considered. Our formulation is based on the basic solution of the second order mutual coherence function evaluated at the receiver plane. For fixed turbulence strength, the coherence length calculated at the receiver plane is found to decrease as the variance of the random displacement is increased. It is shown that as the turbulence becomes stronger, coherence lengths due to off-axis Gaussian beams tend to approach the same value, irrespective of the variance of the random displacement. As expected, the beam spreading is found to be pronounced for larger variance of displacement parameter. Average intensity profiles when atmospheric turbulence is present are plotted for different values of the variance of the random displacement parameter of the off-axis Gaussian beam.

  5. VOLUMETRIC ERROR COMPENSATION IN FIVE-AXIS CNC MACHINING CENTER THROUGH KINEMATICS MODELING OF GEOMETRIC ERROR

    Directory of Open Access Journals (Sweden)

    Pooyan Vahidi Pashsaki

    2016-06-01

    Full Text Available Accuracy of a five-axis CNC machine tool is affected by a vast number of error sources. This paper investigates volumetric error modeling and its compensation to the basis for creation of new tool path for improvement of work pieces accuracy. The volumetric error model of a five-axis machine tool with the configuration RTTTR (tilting head B-axis and rotary table in work piece side A΄ was set up taking into consideration rigid body kinematics and homogeneous transformation matrix, in which 43 error components are included. Volumetric error comprises 43 error components that can separately reduce geometrical and dimensional accuracy of work pieces. The machining accuracy of work piece is guaranteed due to the position of the cutting tool center point (TCP relative to the work piece. The cutting tool is deviated from its ideal position relative to the work piece and machining error is experienced. For compensation process detection of the present tool path and analysis of the RTTTR five-axis CNC machine tools geometrical error, translating current position of component to compensated positions using the Kinematics error model, converting newly created component to new tool paths using the compensation algorithms and finally editing old G-codes using G-code generator algorithm have been employed.

  6. Epimedium Flavonoids Counteract the Side Effects of Glucocorticoids on Hypothalamic-Pituitary-Adrenal Axis

    Directory of Open Access Journals (Sweden)

    Jianhua Huang

    2013-01-01

    Full Text Available Our previous studies demonstrated that the epimedium herb, when simultaneously used with GCs, counteracted suppressive effects of GCs on the HPA axis without adverse influence on the therapeutic action of GCs. Here, total flavones were extracted from the epimedium flavonoids (EFs and then used to investigate whether EFs provide protective effects on the HPA axis. We found that GCs induced a significant decrease in body weight gain, adrenal gland weight gain, and plasma adrenocorticotropin (ACTH and corticosterone levels. After treatment with EFs, body weight gain, adrenal gland weight gain, and plasma corticosterone level were significantly restored, whilst plasma ACTH level was partially elevated. EFs were also shown to promote cell proliferation in the outer layer of adrenal cortex and to enhance the migration of newly divided cells toward the inner layer. To elucidate the underlying mechanisms, the mRNA expression of insulin-like growth factor II (IGF-II was measured, and EFs significantly upregulated IGF-II expression. Our results indicated that EFs counteract the suppression of the HPA axis induced by GCs. This may involve both the ACTH and IGF-II pathways and thereby promote regeneration of the adrenal cortex suggesting a potential clinical application of EFs against the suppressive effects of GCs on the HPA axis.

  7. Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography

    Science.gov (United States)

    Lu, Zenghai; Kasaragod, Deepa K.; Matcher, Stephen J.

    2011-02-01

    We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincaré sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.

  8. Optic axis determination by fiber-based polarization-sensitive swept-source optical coherence tomography

    Science.gov (United States)

    Lu, Zenghai; Kasaragod, Deepa K.; Matcher, Stephen J.

    2011-03-01

    We describe a fiber-based variable-incidence-angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3-D optical axis of birefringent biological tissues. Single-plane VIAPS- OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fiber on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fiber. A proposed algorithm based on the angle between Stokes vectors on the Poincaré sphere is confirmed to work for all settings of the sample arm fiber. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.

  9. Flow and Convective Heat Transfer of Cylinder Misaligned from Aerodynamic Axis of Cyclone Flow

    Directory of Open Access Journals (Sweden)

    I. L. Leukhin

    2008-01-01

    Full Text Available The paper provides and analyzes results of experimental investigations on physical specific features of hydrodynamics and convective heat transfer of a cyclone flow with a group of round cylinders located symmetrically relative to its aerodynamic axis, calculative equations for average and local heat transfer factors at characteristic sections of cylinder surface.

  10. Characterization of blade throw from a 2.3MW horizontal axis wind turbine upon failure

    DEFF Research Database (Denmark)

    Sarlak, Hamid; Sørensen, Jens Nørkær

    2015-01-01

    The present work concerns aerodynamics of thrown objects from a 2.3 MW Horizontal Axis Wind Turbine (HAWT), as a consequence of blade failure. The governing set of ordinary differential equations for the flying objects are derived and numerically solved using a 4th order Runge-Kutta time advancin...

  11. The neuro-immune axis: Prospect for novel treatments for mental disorders

    NARCIS (Netherlands)

    Kraneveld, Aletta D.; de Theije, Caroline G.M.; van Heesch, Floor; Borre, Yuliya; de Kivit, Sander; Olivier, Berend; Korte, Mechiel; Garssen, Johan

    2014-01-01

    Disturbed bidirectional pathways between the (central) nervous system and immune system have been implicated in various mental disorders, including depressive and neurodevelopmental disorders. In this minireview, the role of the neuro-immune axis and its targetability in relation to major depression

  12. Piezotronic Effect in Strain-Gated Transistor of a-Axis GaN Nanobelt.

    Science.gov (United States)

    Yu, Ruomeng; Wang, Xingfu; Peng, Wenbo; Wu, Wenzhuo; Ding, Yong; Li, Shuti; Wang, Zhong Lin

    2015-10-27

    Due to the non-centrosymmetric crystal structures, wurtzite family semiconducting materials possess piezoelectric properties and exhibit polarizations along certain directions upon straining. Utilizing strain-induced piezoelectric polarization charges to modulate the energy band structures and thus to tune/control the transport processes of charge carriers is referred to as the piezotronic effect. Distinct from the previous studies of c-axis GaN nanowires, here we systematically study the piezotronic-effect-induced modifications of energy band structures and the corresponding influence on electronic transport properties of a-axis GaN nanobelts. The physical mechanism is carefully illustrated and further confirmed by theoretical simulations via finite element analysis. The spatial distributions of local carrier concentration and the energy band diagrams of a-axis GaN under various straining conditions are calculated. This work provides a thorough understanding of strain-gated transport properties of a-axis GaN piezotronic transistors and its future applications in semiconductor devices.

  13. Extremely Soft X-Ray Flash as the Indicator of Off-axis Orphan GRB Afterglow

    Science.gov (United States)

    Urata, Yuji; Huang, Kuiyun; Yamazaki, Ryo; Sakamoto, Takanori

    2015-06-01

    We verified the off-axis jet model of X-ray flashes (XRFs) and examined a discovery of off-axis orphan gamma-ray burst (GRB) afterglows. The XRF sample was selected on the basis of the following three factors: (1) a constraint on the lower peak energy of the prompt spectrum {E}{obs}{src}, (2) redshift measurements, and (3) multicolor observations of an earlier (or brightening) phase. XRF 020903 was the only sample selected on the basis of these criteria. A complete optical multicolor afterglow light curve of XRF 020903 obtained from archived data and photometric results in the literature showed an achromatic brightening around 0.7 days. An off-axis jet model with a large observing angle (0.21 rad, which is twice the jet opening half-angle, {θ }{jet}) can naturally describe the achromatic brightening and the prompt X-ray spectral properties. This result indicates the existence of off-axis orphan GRB afterglow light curves. Events with a larger viewing angle (\\gt ∼ 2{θ }{jet}) could be discovered using an 8 m class telescope with wide-field imagers such as the Subaru Hyper-Suprime-Cam and the Large Synoptic Survey Telescope.

  14. Mechanical axis of the lower extremity determined by a new digital photographic method.

    Science.gov (United States)

    Simonsen, Ole Højgaard; Thomsen, Hanne; Skou, Søren Thorgaard; Andersen, Mikkel Meyer

    2013-08-01

    Assessment of the mechanical axis is routine during the examination of patients with lower extremity pain. Long-leg radiographic examination is the gold standard for exact measurement, but it is associated with a significant radiation dose. An alternative method to examine the mechanical axis has been warranted. This article validates a newly developed computerized photograph method to calculate the mechanical axis using a digital photograph. The location of the center of the femoral head was calculated using ink marks on both superior iliac spines. Twenty-five patients (10 women and 15 men) had both legs examined using the photographic method and long-leg radiography examination. The digital photograph method was found to be highly reliable. The interobserver absolute mean difference was 0.99°±0.85°, and the intraobserver absolute mean difference (day-to-day variation) was 1.04°±0.81°. The mechanical axis determined by the 2 methods was highly correlated (R=0.943). The long-leg radiography method was within an average of ±1.88° of the photographic method, with a 95% probability. The photographic method appears to be an effective alternative to conventional long-leg radiography. The photographic method seems convenient in the routine examination of patients with leg pain and children with suspected axial deformity and for follow-up after treatment for malalignment. Calculation coefficients for children and a possible racial difference remain to be studied.

  15. Kalman Filter for Estimation of Sensor Acceleration Using Six - axis Inertial Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Keun [Hankyong National University, Anseong (Korea, Republic of)

    2015-02-15

    Although an accelerometer is a sensor that measures acceleration, it cannot be used by itself to measure the acceleration when the orientation of the sensor changes. This paper introduces a Kalman filter for the estimation of a sensor acceleration based on a six-axis inertial sensor (i.e., a three-axis accelerometer and three-axis gyroscope). The novelty of the proposed Kalman filter lies in the fact that its state vector includes not only the tilt angle variable but also the sensor acceleration. Thus, the filter can explicitly estimate the latter with a high accuracy. The accuracy of acceleration estimates were validated experimentally under three different dynamic conditions, using an optical motion capture system. It could be concluded that the performance of the proposed Kalman filter was comparable to that of the state-of-the-art estimation algorithm employed by the Xsens MTw. The proposed algorithm may be more suitable than inertial/magnetic sensor-based algorithms for various applications adopting six-axis inertial sensors.

  16. Contouring error modeling and simulation of a four-axis motion control system

    Institute of Scientific and Technical Information of China (English)

    张代林; 张旭; 谢经明; 袁楚明; 陈幼平; 汤漾平

    2015-01-01

    A layered modeling method is proposed to resolve the problems resulting from the complexity of the error model of a multi-axis motion control system. In this model, a low level layer can be used as a virtual axis by the high level layer. The first advantage of this model is that the complex error model of a four-axis motion control system can be divided into several simple layers and each layer has different coupling strength to match the real control system. The second advantage lies in the fact that the controller in each layer can be designed specifically for a certain purpose. In this research, a three-layered cross coupling scheme in a four-axis motion control system is proposed to compensate the contouring error of the motion control system. Simulation results show that the maximum contouring error is reduced from 0.208 mm to 0.022 mm and the integration of absolute error is reduced from 0.108 mm to 0.015 mm, which are respectively better than 0.027 mm and 0.037 mm by the traditional method. And in the bottom layer the proposed method also has remarkable ability to achieve high contouring accuracy.

  17. Early development of modern vertical and horizontal axis wind turbines: A review

    Energy Technology Data Exchange (ETDEWEB)

    Shikha; Bhatti, T.S.; Kothari, D.P.

    2005-05-15

    This paper reviews the initial development of the design and operation of modern vertical and horizontal axis wind turbines, with the aim of comparing the development of the two types. Application in developing countries concentrates on the Savonius rotor. The review aims to record important early developments, including the years following the first oil crisis of 1973. (Author)

  18. Paleomagnetic investigation of late Neogene vertical axis rotation and remagnetization in central coastal California

    Science.gov (United States)

    Horns, Daniel M.; Verosub, Kenneth L.

    1995-03-01

    Outcrops of shallow marine sedimentary rocks of the Neogene Purisima Formation and Santa Cruz Mudstone occur throughout the Santa Cruz Mountains and along the coast of Santa Cruz and San Mateo counties in California. Within the Santa Cruz Mountains, the Purisima Formation has been extensively folded and offset by reverse faults. Along the coast, the Purisima Formation and Santa Cruz Mudstone are only gently folded although the Purisima Formation is cut by the San Gregorio Fault Zone. Previous paleomagnetic studies have shown that vertical axis rotation has occurred within some parts of the San Gregorio Fault Zone. As part of a kinematic study of the San Gregorio Fault Zone, this paleomagnetic investigation of the Purisima Formation and Santa Cruz Mudstone was conducted to determine the extent of the vertical axis rotation. The characteristic paleomagnetic directions of the Purisima Formation and Santa Cruz Mudstone, which we interpret as the primary directions, indicate that a clockwise vertical axis rotation of 35 deg to 60 deg has occurred throughout the San Gregorio Zone, whereas no rotation has occurred away from the fault zone. This result suggests that vertical axis rotation is fundamentally related to shear across the San Gregorio Fault Zone. Our work also indicates that while the Purisima Formation and Santa Cruz Mudstone along the coast have retained their primary magnetizations, the Purisima Formation within the Santa Cruz Mountains has been remagnetized after folding.

  19. Aerodynamic Optimization of Vertical Axis Wind Turbine with Trailing Edge Flap

    DEFF Research Database (Denmark)

    Ertem, Sercan; Ferreira, Carlos Simao; Gaunaa, Mac;

    2016-01-01

    Vertical Axis Wind Turbines (VAWT) are competitive concepts for very large scale (10-20 MW)floating ofshore applications. Rotor circulation control (loading control) opens a wide design space to enhance the aerodynamic and operational features of VAWT. The modied linear derivation of the Actuator...

  20. Creating a benchmark of vertical axis wind turbines in dynamic stall for validating numerical models

    DEFF Research Database (Denmark)

    Castelein, D.; Ragni, D.; Tescione, G.;

    2015-01-01

    An experimental campaign using Particle Image Velocimetry (2C-PIV) technique has been conducted on a H-type Vertical Axis Wind Turbine (VAWT) to create a benchmark for validating and comparing numerical models. The turbine is operated at tip speed ratios (TSR) of 4.5 and 2, at an average chord-ba...