4,330 research outputs found
Coal extrusion in the plastic state
Continuous feeding of coal in a compressing screw extruder is described as a method of introducing coal into pressurized systems. The method utilizes the property of many bituminous coals of softening at temperatures from 350 to 425 C. Coal is then fed, much in the manner of common thermoplastics, using screw extruders. Data on the viscosity and extruder parameters for extrusion of Illinois No. 6 coal are presented
Whole body interaction
In this workshop we explore the notation of whole body interaction. We bring together different disciplines to create a new research direction for study of this emerging form of interaction
Statistical Physics of Self-Replication
Self-replication is a capacity common to every species of living thing, and
simple physical intuition dictates that such a process must invariably be
fueled by the production of entropy. Here, we undertake to make this intuition
rigorous and quantitative by deriving a lower bound for the amount of heat that
is produced during a process of self-replication in a system coupled to a
thermal bath. We find that the minimum value for the physically allowed rate of
heat production is determined by the growth rate, internal entropy, and
durability of the replicator, and we discuss the implications of this finding
for bacterial cell division, as well as for the pre-biotic emergence of
self-replicating nucleic acids.Comment: 4+ pages, 1 figur
Reviewing research evidence and the case of participation in sport and physical recreation by black and minority ethnic communities
The paper addresses the implications of using the process of systematic review in the many areas of leisure where there is a dearth of material that would be admitted into conventional Cochrane Reviews. This raises important questions about what constitutes legitimate knowledge, questions that are of critical import not just to leisure scholars, but to the formulation of policy. The search for certainty in an area that lacks conceptual consensus results in an epistemological imperialism that takes a geocentric form. While clearly, there is a need for good research design whatever the style of research, we contend that the wholesale rejection of insightful research is profligate and foolhardy. A mechanism has to be found to capitalise on good quality research of whatever form. In that search, we draw upon our experience of conducting a review of the material available on participation in sport and physical recreation by people from Black and minority ethnic groups. The paper concludes with a proposal for a more productive review process that makes better use of the full panoply of good quality research available. © 2012 © 2012 Taylor & Francis
Abelian functions associated with a cyclic tetragonal curve of genus six
We develop the theory of Abelian functions defined using a tetragonal curve of genus six, discussing in detail the cyclic curve y^4 = x^5 + λ[4]x^4 + λ[3]x^3 + λ[2]x^2 + λ[1]x + λ[0]. We construct Abelian functions using the multivariate sigma-function associated with the curve, generalizing the theory of theWeierstrass℘-function.
We demonstrate that such functions can give a solution to the KP-equation, outlining how a general class of solutions could be generated using a wider class of curves. We also present the associated partial differential equations
satisfied by the functions, the solution of the Jacobi inversion problem, a power series expansion for σ(u) and a new addition formula
Effective lifetime radiation risk for a number of national mammography screening programmes
Background and purpose: The performance of mammography screening programmes is focussed mainly on breast cancer detection rates. However, when the benefits and risks of mammography are considered, the risk of radiation-induced cancer is calculated for only the examined breast using Mean Glandular Dose (MGD). The risk from radiation during mammography is often described as low or minimal. This study aims to evaluate the effective lifetime risk from full field digital mammography (FFDM) for a number of national screening programmes.
Material and Methods: Using an ATOM phantom, radiation doses to multiple organs were measured during standard screening mammography. Sixteen FFDM machines were used and the effective lifetime risk was calculated across the female lifespan for each machine. Once the risks were calculated using the phantom, the total effective lifetime risk across 48 national screening programmes was then calculated; this assumed that all these programmes use FFDM for screening.
Results: Large differences exist in effective lifetime risk, varying from 42.21 [39.12 - 45.30] cases/106 (mean [95% CI]) in the Maltese screening programme to 1099.67 [1019.25 - 1180.09] cases/106 for high breast cancer risk women in the United States of America. These differences are mainly attributed to the commencement age of screening mammography and the time interval between successive screens.
Conclusions: Effective risk should be considered as an additional parameter for the assessment of screening mammography programme performance, especially for those programmes which recommend an early onset and more frequent screening mammography
Penalty finite element approximations of the stationary power- law Stokes problem
Finite element approximations of the stationary power-law Stokes problem using penalty
formulation are considered. A priori error estimates under appropriate smoothness assumptions on the
solutions are established without assuming a discrete version of the BB condition. Numerical solutions
are presented by implementing a nonlinear conjugate gradient metho
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