8,773 research outputs found
Analysis and design of a flat central finned-tube radiator
Computer program based on fixed conductance parameter yields minimum weight design. Second program employs variable conductance parameter and variable ratio of fin length to tube outside radius, and is used for radiator designs with geometric limitations. Major outputs of the two programs are given
Phase Transition in a Three-States Reaction-Diffusion System
A one-dimensional reaction-diffusion model consisting of two species of
particles and vacancies on a ring is introduced. The number of particles in one
species is conserved while in the other species it can fluctuate because of
creation and annihilation of particles. It has been shown that the model
undergoes a continuous phase transition from a phase where the currents of
different species of particles are equal to another phase in which they are
different. The total density of particles and also their currents in each phase
are calculated exactly.Comment: 6 page
The Pacific Northwest story
The establishment of image analysis facilities for the operational utilization of LANDSAT data in Idaho, Oregon, and Washington is discussed. The hardware and software resources are described for each facility along with the range of services
Influence of Weaning Strategy on Animal Welfare in Beef Calves
Alternative strategies can affect the amount of stress that calves encounter at weaning. The strategies being evaluated in this study are fenceline, two-stage, and traditional abrupt. Fenceline weaning involves placing the calves in a pasture adjacent to their cows so they can have contact with each other through the fence. Two-stage weaning utilizes anti-suckling devices that clip into the calves noses and prevent them from suckling their cows. The calves remain with the cows for a short amount of time, then they are weaned and separated from their cows. This allows the stressors of weaning to be faced in two stages. The traditional abrupt weaning is accomplished by separating the calves from the cows and placing them in separate pastures where they have no contact
On Matrix Product States for Periodic Boundary Conditions
The possibility of a matrix product representation for eigenstates with
energy and momentum zero of a general m-state quantum spin Hamiltonian with
nearest neighbour interaction and periodic boundary condition is considered.
The quadratic algebra used for this representation is generated by 2m operators
which fulfil m^2 quadratic relations and is endowed with a trace. It is shown
that {\em not} every eigenstate with energy and momentum zero can be written as
matrix product state. An explicit counter-example is given. This is in contrast
to the case of open boundary conditions where every zero energy eigenstate can
be written as a matrix product state using a Fock-like representation of the
same quadratic algebra.Comment: 7 pages, late
Renormalization of two-loop diagrams in scalar lattice field theory
We present a method to calculate to very high precision the coefficients of
the divergences occuring in two-loop diagrams for a massive scalar field on the
lattice. The approach is based on coordinate space techniques and extensive use
of the precisely known Green's function.Comment: 22 pages, 2 figures, additional results include
Universality properties of the stationary states in the one-dimensional coagulation-diffusion model with external particle input
We investigate with the help of analytical and numerical methods the reaction
A+A->A on a one-dimensional lattice opened at one end and with an input of
particles at the other end. We show that if the diffusion rates to the left and
to the right are equal, for large x, the particle concentration c(x) behaves
like As/x (x measures the distance to the input end). If the diffusion rate in
the direction pointing away from the source is larger than the one
corresponding to the opposite direction the particle concentration behaves like
Aa/sqrt(x). The constants As and Aa are independent of the input and the two
coagulation rates. The universality of Aa comes as a surprise since in the
asymmetric case the system has a massive spectrum.Comment: 27 pages, LaTeX, including three postscript figures, to appear in J.
Stat. Phy
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