KENO IV: an improved Monte Carlo criticality program

KENO IV is a multigroup Monte Carlo criticality program written for the IBM 360 computers. It executes rapidly and is flexibly dimensioned so the allowed size of a problem (i.e., the number of energy groups, number of geometry cards, etc., are arbitrary) is limited only by the total data storage required. The input data, with the exception of cross sections, fission spectra and albedos, may be entered in free form. The geometry input is quite simple to prepare and complicated three-dimensional systems can often be described with a minimum of effort. The results calculated by KENO IV include k-effective, lifetime and generation time, energy-dependent leakages and absorptions, energy- and region-dependent fluxes and region-dependent fission densities. Criticality searches can be made on unit dimensions or on the number of units in an array. A summary of the theory utilized by KENO IV, a section describing the logical program flow, a compilation of the error messages printed by the code and a comprehensive data guide for preparing input to the code are presented. 14 references. (auth

Defect Statistics in the Two Dimensional Complex Ginsburg-Landau Model

The statistical correlations between defects in the two dimensional complex Ginsburg-Landau model are studied in the defect-coarsening regime. In particular the defect-velocity probability distribution is determined and has the same high velocity tail found for the purely dissipative time-dependent Ginsburg-Landau (TDGL) model. The spiral arms of the defects lead to a very different behavior for the order parameter correlation function in the scaling regime compared to the results for the TDGL model.Comment: 24 page

Dynamics of a faceted nematic-smectic B front in thin-sample directional solidification

We present an experimental study of the directional-solidification patterns of a nematic - smectic B front. The chosen system is C_4H_9-(C_6H_{10})_2CN (in short, CCH4) in 12 \mu m-thick samples, and in the planar configuration (director parallel to the plane of the sample). The nematic - smectic B interface presents a facet in one direction -- the direction parallel to the smectic layers -- and is otherwise rough, and devoid of forbidden directions. We measure the Mullins-Sekerka instability threshold and establish the morphology diagram of the system as a function of the solidification rate V and the angle theta_{0} between the facet and the isotherms. We focus on the phenomena occurring immediately above the instability threshold when theta_{0} is neither very small nor close to 90^{o}. Under these conditions we observe drifting shallow cells and a new type of solitary wave, called "faceton", which consists essentially of an isolated macroscopic facet traveling laterally at such a velocity that its growth rate with respect to the liquid is small. Facetons may propagate either in a stationary, or an oscillatory way. The detailed study of their dynamics casts light on the microscopic growth mechanisms of the facets in this system.Comment: 12 pages, 19 figures, submitted to Phys. Rev.

A Comparison Of Outcomes In Osteoarthritis Patients Undergoing Total Hip And Knee Replacement Surgery

Objective The aims of this study were to assess changes in physical function and quality of life with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the instrument of the Medical Outcomes Study SF-36 Health Survey (MOS SF-36), respectively, in patients undergoing hip and knee joint replacement surgery and to compare the responsiveness of these two outcome measures 1 year after surgery. Design One hundred and ninety-four patients with osteoarthritis (OA knee 108, OA hip 86) admitted to four hospitals in Sydney were followed over a period of 1 year at 3 monthly intervals. Results WOMAC measures improved significantly after 1 year for OA hip and OA knee: there was reduction in pain of 71% and 53%, reduction in stiffness of 55% and 43% and improvement in physical function of 68% and 43%, respectively. MOS SF-36 measures in those having hip surgery improved significantly for pain (222%), physical function (247%), physical role functioning (402%), general health (110%), vitality (143%), social functioning (169%) and mental health (114%). For those in the knee surgery group, significant improvement was seen for pain (175%), physical function (197%), physical role functioning (275%), vitality (125%) and social functioning (119%). The WOMAC was a more responsive measure than the MOS SF-36. Conclusion WOMAC and MOS SF-36 detect significant and clinically meaningful changes in outcome after hip and knee replacement. WOMAC requires a smaller sample size and is more responsive in the short term. For a follow-up longer than 6 months MOS SF-36 provides additional information. The improvement in outcomes following hip joint surgery were significantly greater than those following knee surgery

Exploring barriers and facilitators of implementing an at-home SARS-CoV-2 antigen self-testing intervention: The Rapid Acceleration of Diagnostics-Underserved Populations (RADx-UP) initiatives

BACKGROUND: Evaluating community-based programs provides value to researchers, funding entities, and community stakeholders involved in program implementation, and can increase program impact and sustainability. To understand factors related to program implementation, we aimed to capture the perspective of community partners engaged in organizing and executing community-engaged programs to distribute COVID-19 at-home tests in underserved communities. METHODS: We conducted semi-structured interviews and focus groups with community-based stakeholders informed by the Outcomes for Implementation Research framework. RESULTS: Findings describe how community-engaged communication and dissemination strategies drove program adoption among grassroots stakeholders. Establishing and sustaining trusted relationships was vital to engaging partners with aligned values and capacity. Respondents characterized the programs as generally feasible and appropriate, and community partners felt capable of delivering the program successfully. However, they also described an increased burden on their workforce and desired more significant support. Respondents recognized the programs' community engagement practices as a critical facilitator of acceptability and impact. DISCUSSION: Implementation evaluation aims to inform current and future community outreach and engagement efforts with best practices. As we continue to inform and advance community-engaged disaster response practice, a parallel reimagining of public health funding mechanisms and timelines could provide a foundation for trust, collaboration, and community resiliency that endures beyond a given crisis

The mechanism of disaster capitalism and the failure to build community resilience:learning from the 2009 earthquake in L'Aquila, Italy

This paper reflects on what materialised during recovery operations following the earthquake in L'Aquila, Italy, on 6 April 2009. Previous critiques have focused on the actions of the Government of Italy and the Department of Civil Protection (Protezione Civile), with little attention paid to the role of local authorities. This analysis sheds light on how the latter used emergency powers, the command-and-control approach, and top-down planning to manage the disaster context, especially in terms of removal of rubble, implementing safety measures, and allocating temporary accommodation. It discusses how these arrangements constituted the mechanism via which ‘disaster capitalism’ took hold at the local and national level, and how it violated human rights, produced environmental and social impacts, hindered local communities from learning, transforming, and building resilience, and facilitated disaster capitalism and corruption. To make the disaster risk reduction and resilience paradigm more effective, a shift from centralised civil protection to decentralised, inclusive community empowerment systems is needed

D* Production in Deep Inelastic Scattering at HERA

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+$ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$ and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.Comment: 17 pages including 4 figure

Observation of Scaling Violations in Scaled Momentum Distributions at HERA

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of $x$ and $Q^2$ using the ZEUS detector. The evolution of the scaled momentum, $x_p$, with $Q^2,$ in the range 10 to 1280 $GeV^2$, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of $Q^2$.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

Surface effects in nucleation and growth of smectic B crystals in thin samples

We present an experimental study of the surface effects (interactions with the container walls) during the nucleation and growth of smectic B crystals from the nematic in free growth and directional solidification of a mesogenic molecule ($C_4H_9-(C_6H_{10})_2CN$) called CCH4 in thin (of thickness in the 10 $\mu$m range) samples. We follow the dynamics of the system in real time with a polarizing microscope. The inner surfaces of the glass-plate samples are coated with polymeric films, either rubbed polyimid (PI) films or monooriented poly(tetrafluoroethylene) (PTFE) films deposited by friction at high temperature. The orientation of the nematic and the smectic B is planar. In PI-coated samples, the orientation effect of SmB crystals is mediated by the nematic, whereas, in PTFE-coated samples, it results from a homoepitaxy phenomenon occurring for two degenerate orientations. A recrystallization phenomenon partly destroys the initial distribution of crystal orientations. In directional solidification of polycrystals in PTFE-coated samples, a particular dynamics of faceted grain boundary grooves is at the origin of a dynamical mechanism of grain selection. Surface effects also are responsible for the nucleation of misoriented terraces on facets and the generation of lattice defects in the solid.Comment: 15 pages, 24 figures, submitted to PR