930 research outputs found

    The field theoretic derivation of the contact value theorem in planar geometries and its modification by the Casimir effect

    Full text link
    The contact value theorem for Coulomb gases in planar or film-like geometries is derived using a Hamiltonian field theoretic representation of the system. The case where the film is enclosed by a material of different dielectric constant to that of the film is shown to contain an additional Casimir-like term which is generated by fluctuations of the electric potential about its mean-field value.Comment: Link between Sine-Gordon and Coulomb gas pressures via subtraction of self interaction terms included. Discussion of results within Debye-Huckel approximation included. Added reference

    History effect in inhomogeneous superconductors

    Full text link
    A model was proposed to account for a new kind of history effect in the transport measurement of a sample with inhomogeneous flux pinning coupled with flux creep. The inhomogeneity of flux pinning was described in terms of alternating weak pinning (lower jc) and strong pinning region (higher jc). The flux creep was characterized by logarithmic barrier. Based on this model, we numerically observed the same clockwise V-I loops as reported in references. Moreover, we predicted behaviors of the V-I loop at different sweeping rates of applied current dI/dt or magnetic fields Ba, etc. Electric transport measurement was performed in Ag-sheathed Bi2-xPbxSr2Ca2Cu3Oy tapes immersed in liquid nitrogen with and without magnetic fields. V-I loop at certain dI/dt and Ba was observed. It is found that the area of the loop is more sensitive to dI/dt than to Ba, which is in agreement well with our numerical results.Comment: To appear in Phys Rev B, October 1 Issu

    Domain regime in two-dimensional disordered vortex matter

    Full text link
    A detailed numerical study of the real space configuration of vortices in disordered superconductors using 2D London-Langevin model is presented. The magnetic field BB is varied between 0 and Bc2B_{c2} for various pinning strengths Δ\Delta. For weak pinning, an inhomogeneous disordered vortex matter is observed, in which the topologically ordered vortex lattice survives in large domains. The majority of the dislocations in this state are confined to the grain boundaries/domain walls. Such quasi-ordered configurations are observed in the intermediate fields, and we refer it as the domain regime (DR). The DR is distinct from the low-field and the high-fields amorphous regimes which are characterized by a homogeneous distribution of defects over the entire system. Analysis of the real space configuration suggests domain wall roughening as a possible mechanism for the crossover from the DR to the high-field amorphous regime. The DR also shows a sharp crossover to the high temperature vortex liquid phase. The domain size distribution and the roughness exponent of the lattice in the DR are also calculated. The results are compared with some of the recent Bitter decoration experiments.Comment: 9 pages, 9 figure

    Changes in Physician Knowledge, Attitudes, Beliefs, and Practices regarding Lung Cancer Screening

    Get PDF
    More patients die of lung cancer than breast, colorectal, and prostate cancers combined (1). After the National Lung Screening Trial finding of a 20% relative reduction in mortality of lung cancer with lung cancer screening (LCS) by low-dose computed tomography (LDCT) (2), the U.S. Preventive Services Task Force published recommendations for LCS in high-risk patients (current and former heavy smokers aged 55–80 yr) annually with LDCT (3)

    The composition of Singaporean shopping centres

    Get PDF
    With its growing population but limited supply of land, Singapore has seen a huge increase in the number and size of shopping centres in recent years. This growth has led to two rather contradictory outcomes - more choice for retailers in their efforts to reach customers but also claims that too many of the centres contain the same types of retailers and contain no real differentiation in their offerings. This paper looks at this trend and reports on a survey of the composition of store types in a wide range of Singaporean shopping centres to consider whether or not these views are based on a full picture of the roles played by these shopping centres

    Сутність адміністративного права за новою класифікацією юриспруденції

    Get PDF
    На основі новітніх підходів до розумінні завдань, об’єктів і класифікації юридичних наук запропонована перспектива розвитку адміністративного права і процесу, які повинні трансформуватися в нові юридичні науки: базисноантиделыктне «Адміністра­тивне право України», процедурне «Админо­регламентное право України» та у низку регулятивних юридичних наук, а також розробити Адміністративний кодекс України, Адміно-регламентній кодекс України, відповідні регулятивні кодекси.На основе новейших подходов к понимании задач, объектов и классификации юридических наук предложена перспектива развития административного права и процес­са, которые должны трансформироваться в новые юридические науки: базисноанти­деликтное «Административное право Украины», процедурное «Админо­регламентное право Украины» и ряд регулятивных юридических наук, а также разработать Административный кодекс Украины, Админо-регламентный кодекс Украины, соответствую­щие регулятивные кодексы.On the basis of the newest fittings to for understanding of tasks, objects and classification of legal sciences the prospect of development of administrative law and process is offered, which must be transformed in new legal sciences: basisuntidelictical the «Administrative law of Ukraine», procedural «Administrative-reglamental law of Ukraine» and the row of regulative legal sciences, and also to develop the Administrative code of Ukraine, Administrative­-reglamental code of Ukraine, proper regulative codes

    Hysteretic behavior of the vortex lattice at the onset of the second peak for HgBa2_2CuO4+δ_{4+\delta} superconductor

    Full text link
    By means of local Hall probe ac and dc permeability measurements we investigated the phase diagram of vortex matter for the HgBa2_2CuO4+δ_{4+\delta } superconductor in the regime near the critical temperature. The second peak line, HspH_{\rm sp}, in contrast to what is usually assumed, doesn't terminate at the critical temperature. Our local ac permeability measurements revealed pronounced hysteretic behavior and thermomagnetic history effects near the onset of the second peak, giving evidence for a phase transition of vortex matter from an ordered qausilattice state to a disordered glass

    Transient early wheeze and lung function in early childhood associated with chronic obstructive pulmonary disease genes

    Get PDF
    Background It has been hypothesized that a disturbed early lung development underlies the susceptibility to chronic obstructive pulmonary disease (COPD). Little is known about whether subjects genetically predisposed to COPD show their first symptoms or reduced lung function in c

    Dynamic Ordering and Transverse Depinning of a Driven Elastic String in a Disordered Media

    Full text link
    We examine the dynamics of an elastic string interacting with quenched disorder driven perpendicular and parallel to the string. We show that the string is the most disordered at the depinning transition but with increasing drive partial ordering is regained. For low drives the noise power is high and we observe a 1/f^2 noise signature crossing over to a white noise character with low power at higher drives. For the parallel driven moving string there is a finite transverse critical depinning force with the depinning transition occuring by the formation of running kinks.Comment: 4 pages, 4 postscript figure

    Opinions and Practices of Lung Cancer Screening by Physician Specialty

    Get PDF
    BACKGROUND In response to the National Lung Screening Trial, numerous professional organizations published guidelines recommending annual lung cancer screening with low-dose computed tomography (LDCT) for high-risk patients. Prior studies found that physician attitudes and knowledge about lung cancer screening directly impacts the number of screening exams ordered.METHODS In 2015, we surveyed 34 pulmonologists and 186 primary care providers (PCPs) to evaluate opinions and practices of lung cancer screening in a large academic medical center. We compared PCP and pulmonologist responses using t-tests and χ2 tests.RESULTS The overall survey response rate was 40% (39% for PCPs and 50% for pulmonologists). Pulmonologists were more likely than PCPs to report lung cancer screening as beneficial for patients (88.2% versus 37.7%, P < .0001) and as being cost-effective (47.1% versus 14.3%, P = .02). More pulmonologists (76%) reported ordering a LDCT for screening in the past 12 months compared to PCPs (41%, P = .012). Pulmonologists and PCPs reported similar barriers to referring patients for lung cancer screening, including patient costs (82.4% versus 77.8%), potential for emotional harm (58.8% versus 58.3%), high false positive rate (47.1% versus 69.4%), and likelihood for medical complications (47.1% versus 59.7%).LIMITATIONS Our results are generalizable to academic medical centers and responses may be susceptible to recall bias, non-response bias, and social desirability bias.CONCLUSION We found significant differences in opinions and practices between PCPs and pulmonologists regarding lung cancer screening referrals and perceived benefits. As lung cancer screening continues to emerge in clinical practice, it is important to understand these differences across provider specialty to ensure screening is implemented and offered to patients appropriately
    corecore