275 research outputs found
Testing an Optimised Expansion on Z_2 Lattice Models
We test an optimised hopping parameter expansion on various Z_2 lattice
scalar field models: the Ising model, a spin-one model and lambda (phi)^4. We
do this by studying the critical indices for a variety of optimisation
criteria, in a range of dimensions and with various trial actions. We work up
to seventh order, thus going well beyond previous studies. We demonstrate how
to use numerical methods to generate the high order diagrams and their
corresponding expressions. These are then used to calculate results numerically
and, in the case of the Ising model, we obtain some analytic results. We
highlight problems with several optimisation schemes and show for the best
scheme that the critical exponents are consistent with mean field results to at
least 8 significant figures. We conclude that in its present form, such
optimised lattice expansions do not seem to be capturing the non-perturbative
infra-red physics near the critical points of scalar models.Comment: 47 pages, some figures in colour but will display fine in B
Influence of e-Content Based Coaching on Selected Fundamental Skills in Field Hockey
The purpose of the study was to examine the influence of e-content based coaching on selected fundamental skills in Field Hockey. To achieve the purpose of this study 30 male under graduate students from Meenatchi Ramasamy group of institutions, Thathanur, Tamilnadu, India were selected as subjects and their age ranged between 17 and 20 years. The study was formulated as a true random group design, consisting of a pre-test and post-test. The subjects were randomly assigned to two equal groups of fifteen each and named as Group ‘A’ and Group ‘B’. Group ‘A’ underwent teaching & coaching with e-content package and Group ‘B’ undergone teaching & coaching without e-content package. The teaching & coaching with e-content group were shown the content developed electronically by the investigators and the other group was given teaching & coaching only in the field. Both the groups undergone respective schedule for six weeks on alternate days. Teaching & coaching session in the field lasted for 60 minutes and e-content schedule was meted out for 20 minutes. The fundamental skills namely straight hit, wrong foot hit, straight push, wrong foot push, straight flick, wrong foot flick and scoop in Hockey were selected as variables. The subjective rating was done by three qualified coaches on each skill selected in this study. The rating was done on 10 points scale by each coach and average on each skill was taken as individual score. Analysis of covariance was used, where the final means were adjusted for differences in the initial means, and the adjusted means were tested for significance. From the analysis of data it was found that the teaching & coaching combined with e-content package group showed significant improvement on all selected fundamental skills in Field Hockey
An optimized perturbation expansion for a global O(2) theory
We use an optimised perturbation expansion called the linear delta-expansion to study the phase transition in a Higgs sector with a continuous symmetry and large couplings. Our results show how to use this non-perturbative method successfully for such problems. We also show how to simplify the method without losing any flexibility
Developing GIS-based disaster management system for local authority - Case study in Malaysia
This paper describes the development of geospatial-based disaster management system for an agency at regional level. Important aspects of the system such as spatial data, geospatial database, interface and specific modules for the disaster management system form major discussions of this paper. The Pengerang Disaster Management System (PDMS) is being developed for a local authority in one of the Malaysian states who’s been given a task to monitor the surrounding environmental aspects. The local authority manages one of the largest oil and gas refinery plant in South East Asia region in collaboration with national oil company, PETRONAS. The PDMS, is a one-stop centre (dashboard) for managing the operations with other agencies or stakeholders such as police, marine, army, medical team, fire and rescue units. We anticipate many aspects of disaster management could trigger from this pilot project and thus provide some interesting ideas for a local authority in managing man-made disaster such as fire, other oil and gas related incidents. Some features of the developed system such as online map publishing services, data flow and other geospatial analysis during the event will be discussed in this paper. Near-future work and a big picture of the disaster management approach (with an emphasis to oil and gas incident and scenario) also will be highlighted
PEBSI - A Monte Carlo simulator for bremsstrahlung arising from electrons colliding with thin solid-state targets
We present a Monte Carlo code dedicated to the simulation of bremsstrahlung
arising in collisions of polarized electrons with thin target foils. The
program consists of an electron transport algorithm taking into account elastic
electron-nucleus scattering and inelastic collisions with target electrons as
well as a treatment of polarized-electron bremsstrahlung emission. Good
agreement is found between the predictions of the electron transport code and
data stemming from other simulation programs and experiments. In addition, we
present first results from the bremsstrahlung simulation which indicate a
significant decrease in the degree of linear polarization of bremsstrahlung
even for the thinnest gold targets considered
Catalytic living ring-opening metathesis polymerization
In living ring-opening metathesis polymerization (ROMP), a transition-metal–carbene complex polymerizes ring-strained olefins with very good control of the molecular weight of the resulting polymers. Because one molecule of the initiator is required for each polymer chain, however, this type of polymerization is expensive for widespread use. We have now designed a chain-transfer agent (CTA) capable of reducing the required amount of metal complex while still maintaining full control over the living polymerization process. This new method introduces a degenerative transfer process to ROMP. We demonstrate that substituted cyclohexene rings are good CTAs, and thereby preserve the ‘living’ character of the polymerization using catalytic quantities of the metal complex. The resulting polymers show characteristics of a living polymerization, namely narrow molecular-weight distribution, controlled molecular weights and block copolymer formation. This new technique provides access to well- defined polymers for industrial, biomedical and academic use at a fraction of the current costs and significantly reduced levels of residual ruthenium catalyst
Factors associated with spontaneous stone passage in a contemporary cohort of patients presenting with acute ureteric colic. Results from the MIMIC Study (A Multi-centre cohort study evaluating the role of Inflammatory Markers in patients presenting with acute ureteric Colic)
Objectives
There is conflicting data on the role of white blood cell count (WBC) and other inflammatory markers in spontaneous stone passage in patients with acute ureteric colic. The aim of the study was to assess the relationship of WBC and other routinely collected inflammatory and clinical markers including stone size, stone position and Medically Expulsive Therapy use (MET) with spontaneous stone passage (SSP) in a large contemporary cohort of patients with acute ureteric colic.
Subjects and Methods
Multi‐centre retrospective cohort study coordinated by the British Urology Researchers in Surgical Training (BURST) Research Collaborative at 71 secondary care hospitals across 4 countries (United Kingdom, Republic of Ireland, Australia and New Zealand). 4170 patients presented with acute ureteric colic and a computer tomography confirmed single ureteric stone. Our primary outcome measure was SSP as defined by the absence of need for intervention to assist stone passage. Multivariable mixed effects logistic regression was used to explore the relationship between key patient factors and SSP.
Results
2518 patients were discharged with conservative management and had further follow up with a SSP rate of 74% (n = 1874/2518). Sepsis after discharge with conservative management was reported in 0.6% (n = 16/2518). On multivariable analysis neither WBC, Neutrophils or CRP were seen to predict SSP, with an adjusted OR of 0.97 [95% CI 0.91 to 1.04, p = 0.38], 1.06 [95% CI 0.99 to 1.13, p = 0.1] and 1.00 [95% CI 0.99 to 1.00, p = 0.17], respectively. Medical expulsive therapy (MET) also did not predict SSP [adjusted OR 1.11 [95% CI 0.76 to 1.61]). However, stone size and stone position were significant predictors. SSP for stones 7mm. For stones in the upper ureter the SSP rate was 52% [95% CI 48 to 56], middle ureter was 70% [95% CI 64 to 76], and lower ureter was 83% [95% CI 81 to 85].
Conclusion
In contrast to the previously published literature, we found that in patients with acute ureteric colic who are discharged with initial conservative management, neither WBC, Neutrophil count or CRP help determine the likelihood of spontaneous stone passage. We also found no overall benefit from the use of MET. Stone size and position are important predictors and our findings represent the most comprehensive stone passage rates for each mm increase in stone size from a large contemporary cohort adjusting for key potential confounders. We anticipate that these data will aid clinicians managing patients with acute ureteric colic and help guide management decisions and the need for intervention
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