596 research outputs found

    The distortion of a cylinder with non-uniform axial heat conduction

    Full text link
    Closed form expressions are developed for the thermoelastic curvature of the initially plane end faces of a traction free cylinder subjected to arbitrary axisymmetric heat flux, the curved surfaces being assumed insulated. The solution is developed from a potential function representation of displacement and temperature for an elastic layer. The reciprocal theorem is invoked to show that the tractions at the curved surface of the cylinder vary linearly along the axis and they are removed by superposition of biaxial bending. It is found that the curvature of the plane ends depends on the local heat flux and the mean heat flux, whilst the cylindrical face distorts into a cone.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42669/1/10659_2004_Article_BF00042521.pd

    Tricritical Behavior of Two-Dimensional Scalar Field Theories

    Full text link
    We compute by Monte Carlo numerical simulations the critical exponents of two-dimensional scalar field theories at the λϕ6\lambda\phi^6 tricritical point. The results are in agreement with the Zamolodchikov conjecture based on conformal invariance.Comment: 13 pages, uuencode tar-compressed Postscript file, preprint numbers: IF/UFRJ/25/94, DFTUZ 94.06 and NYU--TH--94/10/0

    Monopole Percolation in pure gauge compact QED

    Full text link
    The role of monopoles in quenched compact QED has been studied by measuring the cluster susceptibility and the order parameter nmax/ntotn_{max}/n_{tot} previously introduced by Hands and Wensley in the study of the percolation transition observed in non-compact QED. A correlation between these parameters and the energy (action) at the phase transition has been observed. We conclude that the order parameter nmax/ntotn_{max}/n_{tot} is a sensitive probe for studying the phase transition of pure gauge compact QED.Comment: LaTeX file + 4 PS figures, 12 pag., Pre-UAB-FT-308 ILL-(TH)-94-1

    Self-Averaging, Distribution of Pseudo-Critical Temperatures and Finite Size Scaling in Critical Disordered Systems

    Full text link
    The distributions P(X)P(X) of singular thermodynamic quantities in an ensemble of quenched random samples of linear size ll at the critical point TcT_c are studied by Monte Carlo in two models. Our results confirm predictions of Aharony and Harris based on Renormalization group considerations. For an Ashkin-Teller model with strong but irrelevant bond randomness we find that the relative squared width, RXR_X, of P(X)P(X) is weakly self averaging. RX∌lα/ÎœR_X\sim l^{\alpha/\nu}, where α\alpha is the specific heat exponent and Îœ\nu is the correlation length exponent of the pure model fixed point governing the transition. For the site dilute Ising model on a cubic lattice, known to be governed by a random fixed point, we find that RXR_X tends to a universal constant independent of the amount of dilution (no self averaging). However this constant is different for canonical and grand canonical disorder. We study the distribution of the pseudo-critical temperatures Tc(i,l)T_c(i,l) of the ensemble defined as the temperatures of the maximum susceptibility of each sample. We find that its variance scales as (ÎŽTc(l))2∌l−2/Îœ(\delta T_c(l))^2 \sim l^{-2/\nu} and NOT as ∌l−d.Wefindthat\sim l^{-d}. We find that R_\chiisreducedbyafactorof is reduced by a factor of \sim 70withrespectto with respect to R_\chi (T_c)bymeasuring by measuring \chiofeachsampleat of each sample at T_c(i,l).Weanalyzecorrelationsbetweenthemagnetizationatcriticality. We analyze correlations between the magnetization at criticality m_i(T_c,l)andthepseudo−criticaltemperature and the pseudo-critical temperature T_c(i,l)intermsofasampleindependentfinitesizescalingfunctionofasampledependentreducedtemperature in terms of a sample independent finite size scaling function of a sample dependent reduced temperature (T-T_c(i,l))/T_c$. This function is found to be universal and to behave similarly to pure systems.Comment: 31 pages, 17 figures, submitted to Phys. Rev.

    Prolapse severity, symptoms and impact on quality of life among women planning sacrocolpopexy

    Full text link
    Objectives: To explore the relationship between severity of pelvic organ prolapse (POP), symptoms of pelvic dysfunction and quality of life using validated measures. Method: Baseline data from 314 participants in the Colpopexy And Urinary Reduction Efforts (CARE) trial were analyzed. Pelvic symptoms and impact were assessed using the Pelvic Floor Distress Inventory (PFDI) and the Pelvic Floor Impact Questionnaire (PFIQ). PFDI and PFIQ scores were compared by prolapse stage and history of incontinence or POP surgery. Regression analyses were performed to identify other predictors of symptoms and impact. Results: Women were predominantly (90%) Caucasian and had mean age of 61 years. Women with stage II POP, especially those with prior surgery, reported more symptoms and impact than women with more advanced POP. There were no other significant predictors of symptoms or life impact. Conclusions: Women planning sacrocolpopexy with stage II prolapse and prior pelvic surgery reported more symptoms and quality of life impact than those with more advanced prolapse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135603/1/ijgo24.pd

    Ising cubes with enhanced surface couplings

    Full text link
    Using Monte Carlo techniques, Ising cubes with ferromagnetic nearest-neighbor interactions and enhanced couplings between surface spins are studied. In particular, at the surface transition, the corner magnetization shows non-universal, coupling-dependent critical behavior in the thermodynamic limit. Results on the critical exponent of the corner magnetization are compared to previous findings on two-dimensional Ising models with three intersecting defect lines.Comment: 4 pages, 2 figures included, submitted to Phys. Rev.

    Systematic Regge theory analysis of omega photoproduction

    Get PDF
    Systematic analysis of available data for ω\omega-meson photoproduction is given in frame of Regge theory. At photon energies above 20 GeV the Îł+p→ω+p\gamma{+}p{\to}\omega{+}p reaction is entirely dominated by Pomeron exchange. However, it was found that Pomeron exchange model can not reproduce the Îł+p→ρ+p\gamma{+}p{\to}\rho{+}p and Îł+p→ω+p\gamma{+}p{\to}\omega{+}p data at high energies simultaneously with the same set of parameters. The comparison between ρ\rho and ω\omega data indicates a large room for meson exchange contribution to ω\omega-meson photoproduction at low energies. It was found that at low energies the dominant contribution comes from π\pi and f2f_2-meson exchanges. There is smooth transition between the meson exchange model at low energies and Regge theory at high energies.Comment: 7 pages, 8 figures, revtex

    Foreword: Control and Conservation of Lampreys Beyond 2020 – Proceedings from the 3rd Sea Lamprey International Symposium (SLIS III)

    Get PDF
    This special issue summarizes outcomes from the 3rd Sea Lamprey International Symposium (SLIS III; Fig. 1) held 28 July – 2 August 2019 at Wayne State University in Detroit, Michigan, U.S.A. The first two symposia (SLIS I and SLIS II) were held 30 July – 8 August 1979 at Northern Michigan University in Marquette, Michigan and 14–18 August 2000 at Lake Superior State University in Sault Ste. Marie, Michigan, respectively. The published volumes from these symposia in 1980 (Canadian Journal of Fisheries and Aquatic Sciences, Volume 37, Issue 11) and 2003 (Journal of Great Lakes Research Volume 29, Supplement 1) have been invaluable references for the broader scientific community and for management agencies around the Laurentian Great Lakes; cited over 4800 and 3300 times, respectively. SLIS III was attended by over 150 scientists, biologists, resource managers, graduate students, and Commission advisors, including participants from Australia, Canada, China, Japan, New Zealand, Portugal, Spain, the United Kingdom, and the United States (Fig. 2). Similar to SLIS I and SLIS II, the goals of SLIS III were to provide a forum to (i) update and publish information on sea lamprey control and research on lampreys since SLIS II, (ii) exchange knowledge and ideas to bring practitioners to a common plateau of understanding, and (iii) develop innovative initiatives and stimulate new vigor in efforts to control sea lamprey in the Great Lakes and to conserve lampreys in their native ranges. The emphasis on conservation of lampreys is unique to SLIS III and reflects a heightened international recognition that scientific and management advances supporting sea lamprey control in the Great Lakes can benefit the global effort to conserve native lampreys and vice versa

    Universal Magnetic Properties of La2−ήSrήCuO4La_{2-\delta} Sr_{\delta} Cu O_4 at Intermediate Temperatures

    Full text link
    We present the theory of two-dimensional, clean quantum antiferromagnets with a small, positive, zero temperature (TT) stiffness ρs\rho_s, but with the ratio kBT/ρsk_B T / \rho_s arbitrary. Universal scaling forms for the uniform susceptibility (χu\chi_u), correlation length(Ο\xi), and NMR relaxation rate (1/T11/T_1) are proposed and computed in a 1/N1/N expansion and by Mont\'{e}-Carlo simulations. For large kBT/ρsk_B T/\rho_s, χu(T)/T\chi_u (T)/T and TΟ(T)T\xi(T) asymptote to universal values, while 1/T1(T)1/T_{1}(T) is nearly TT-independent. We find good quantitative agreement with experiments and some numerical studies on La2−ήSrÎŽCuO4La_{2-\delta} Sr_{\delta} Cu O_4.Comment: 14 pages, REVTEX, 1 postscript figure appende

    Tumour-induced hypoglycaemia:A narrative review

    Get PDF
    Objective: To provide an overview of the pathogenesis and clinical features of tumour-induced hypoglycaemia (TIH), its effective diagnostic work-up and management strategies and the challenges involved. Background: Hypoglycaemia, defined by a plasma blood glucose level <3.0 mmol/L (<54 mg/dL), results from failure of glucose homeostasis. Although multiple scenarios contribute to the onset of hypoglycaemia, certain tumours represent an important, although relatively uncommon group of causative factors. In patients with unexplained hypoglycaemia, it is important to conduct a careful clinical assessment, with detailed investigations to ascertain the underlying cause(s), and initiate appropriate and effective therapies. TIH often presents a clinical challenge for both accurate and timely diagnosis and effective management. Methods: We performed a narrative literature review using PubMed and search-term "Tumour-Induced Hypoglycaemia", with articles written in English. Conclusions: There are two main groups of TIH: insulinoma and non-islet cell tumours (NICTs). Insulinomas are the commonest form of pancreatic neuroendocrine tumour, and a well-recognised cause of hyperinsulinaemia associated with recurrent hypoglycaemia. Conversely, NICTs mediate hypoglycaemia through the excessive production of big insulin-like growth factor 2 (IGF2), that cross-reacts with the insulin receptor. Through careful biochemical assessment, accurate diagnosis of Insulinoma versus NICTs provides a rationale for effective and individually tailored management
    • 

    corecore