Surface width of the Solid-On-Solid models

The low-temperature series for the surface width of the Absolute value Solid-On-Solid model and the Discrete Gaussian model both on the square lattice and on the triangular lattice are generated to high orders using the improved finite-lattice method. The series are analyzed to give the critical points of the roughening phase transition for each model.Comment: 3 pages, LaTeX, to appear in the proceedings of Lattice'97, Edinburgh, Scotland, July 22--26, 199

High-temperature expansion of the magnetic susceptibility and higher moments of the correlation function for the two-dimensional XY model

We calculate the high-temperature series of the magnetic susceptibility and the second and fourth moments of the correlation function for the XY model on the square lattice to order $\beta^{33}$ by applying the improved algorithm of the finite lattice method. The long series allow us to estimate the inverse critical temperature as $\beta_c=1.1200(1)$, which is consistent with the most precise value given previously by the Monte Carlo simulation. The critical exponent for the multiplicative logarithmic correction is evaluated to be $\theta=0.054(10)$, which is consistent with the renormalization group prediction of $\theta={1/16}$.Comment: 13 pages, 8 Postscript figure

New algorithm of the high-temperature expansion for the Ising model in three dimensions

New algorithm of the finite lattice method is presented to generate the high-temperature expansion series of the Ising model. It enables us to obtain much longer series in three dimensions when compared not only to the previous algorithm of the finite lattice method but also to the standard graphical method. It is applied to extend the high-temperature series of the simple cubic Ising model from beta^{26} to beta^{46} for the free energy and from beta^{25} to beta^{32} for the magnetic susceptibility.Comment: 3 pages, Lattice2002(spin

Higher orders of the high-temperature expansion for the Ising model in three dimensions

The new algorithm of the finite lattice method is applied to generate the high-temperature expansion series of the simple cubic Ising model to $\beta^{50}$ for the free energy, to $\beta^{32}$ for the magnetic susceptibility and to $\beta^{29}$ for the second moment correlation length. The series are analyzed to give the precise value of the critical point and the critical exponents of the model.Comment: Lattice2003(Higgs), 3 pages, 2 figure

New Algorithm of the Finite Lattice Method for the High-temperature Expansion of the Ising Model in Three Dimensions

We propose a new algorithm of the finite lattice method to generate the high-temperature series for the Ising model in three dimensions. It enables us to extend the series for the free energy of the simple cubic lattice from the previous series of 26th order to 46th order in the inverse temperature. The obtained series give the estimate of the critical exponent for the specific heat in high precision.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Letter

Low-Temperature Series for the Correlation Length in d=3d=3 Ising Model

We extend low-temperature series for the second moment of the correlation function in $d=3$ simple-cubic Ising model from $u^{15}$ to $u^{26}$ using finite-lattice method, and combining with the series for the susceptibility we obtain the low-temperature series for the second-moment correlation length to $u^{23}$. An analysis of the obtained series by inhomogeneous differential approximants gives critical exponents $2\nu^{\prime} + \gamma^{\prime} \approx 2.55$ and $2\nu^{\prime} \approx 1.27$.Comment: 13 pages + 5 uuencoded epsf figures in Latex, OPCT-94-

Large-qq expansion of the specific heat for the two-dimensional qq-state Potts model

We have calculated the large-$q$ expansion for the specific heat at the phase transition point in the two-dimensional $q$-state Potts model to the 23rd order in $1/\sqrt{q}$ using the finite lattice method. The obtained series allows us to give highly convergent estimates of the specific heat for $q>4$ on the first order transition point. The result confirm us the correctness of the conjecture by Bhattacharya et al. on the asymptotic behavior of the specific heat for $q \to 4_+$.Comment: 7 pages, LaTeX, 2 postscript figure

Effect of low-density diets on broiler breeder and offspring performance

Restricted feeding of broiler breeders is required to obtain good reproductive performance. Current practical feed restriction levels can result in hunger feeling and chronic stress, particularly during the rearing period. On the basis of literature data, low-density diets might improve bird welfare. Recent findings also indicate that low-density broiler breeder diets can reduce offspring mortality. In this thesis, effects of low-density breeder diets on bird welfare and breeder and offspring performance were evaluated. Breeder treatments involved: 1) normal density diets (ND), 2) diets with 12 and 11 % reduced nutrient densities during rearing and laying (LD12 and LD11), 3) diets with 23 and 21 % reduced nutrient densities during rearing and laying (LD23 and LD21), 4) as 2), but with oats and sugar beet pulp instead of palm kernel meal, wheat bran, wheat gluten feed and sunflower seed meal in the diets (LD12 OP and LD11 OP ), and 5) LD11 diets during rearing followed by ND diets during laying.Feeding LD23 diets reduced stereotypic pecking behaviour and increased time spent on sitting during the first half of the rearing period. LD23 and LD12 OP diets reduced feed intake motivation during rearing. It was concluded that LD23 can improve bird welfare during the first half of the rearing period. However, LD21 impaired bird welfare during laying.LD12 OP and LD11 OP diets gave significantly lower live weights during rearing and laying. Low-density diets delayed reproductive tract development at 24 weeks of age, which was followed by an increased development between week 24 and 26. Changes in bird development were related to changes in nutrient digestibility and utilization of digested nutrients. Egg weights and amount of egg white increased and embryonic development was improved on low-density diets. Laying percentage was significantly higher on LD11 diets. LD11 diets increased live weight of offspring of 29-week-old breeders significantly in comparison with ND diets. Low-density breeder diets resulted in a significant reduction in offspring mortality when breeders were 60 weeks of age. Antibody titres in offspring indicated that nutrients in eggs with a relatively low weight were used for growth rather than for immune system development. It was concluded that low-density broiler breeder diets can improve offspring performance and offspring vitality