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Negative thermal expansion (NTE) describes the anomalous propensity of materials to shrink when heated. Since its discovery, the NTE effect has been found in a wide variety of materials with an array of magnetic, electronic and structural properties. In some cases, the NTE originates from phase competition arising from the electronic or magnetic degrees of freedom but we here focus on a particular class of NTE which originates from intrinsic dynamical origins related to the lattice degrees of freedom, a property we term structural negative thermal expansion (SNTE). Here we review some select cases of NTE which strictly arise from anharmonic phonon dynamics, with a focus on open perovskite lattices. We find that NTE is often present close in proximity to competing structural phases, with structural phase transition lines terminating near T=0 K yielding the most prominent displays of the SNTE effect. We further provide a theoretical model to make precise the proposed relationship among the signature behavior of SNTE, the proximity of these systems to structural quantum phase transitions and the effects of phase fluctuations near these unique regions of the structural phase diagram. The effects of compositional disorder on NTE and structural phase stability in perovskites are discussed.

This research was carried out to investigate the correlations among age, yolk fatty acids content, and incubation results of broiler breeders. Egg samples were obtained from Ross 308 broiler breeder parent stock at 28, 45, and 65 wk of age. A total of 1,800 eggs were used for incubation results of each age period. The mean values of hatchability of fertile eggs (H/F) were 94.04 ± 0.42, 91.36 ± 1.08, 85.97 ± 0.96%, values for hatchability of total eggs (H) were 92.00 ± 0.47, 83.61 ± 1.23, 62.78 ± 1.57%, and fertility ratios (F) were 97.83 ± 0.30, 91.50 ± 0.54, and 73.00 ± 1.55% at 28, 45, and 65 wk of age, respectively (P < 0.01). The mean values of early embryonic mortality and hatched chick weight were 2.73 ± 0.27, 4.01 ± 0.56, 8.93 ± 0.89% and 36.58 ± 0.51, 42.47 ± 0.48, 45.31 ± 0.96 g, at 28, 45, and 65 wk of age, respectively (P < 0.01). Myristic acid and linoleic acid contents of yolk significantly decreased with increasing age of broiler breeder (P .< 0.01). The mean yolk myristic acid contents were 0.34 ± 0.02, 0.29 ± 0.06, and 0.24 ± 0.01 mg/g, and linoleic acid contents were 21.60 ± 1.26, 16.05 ± 3.04, and 13.87 * 0.49 mg/g at 28, 45, and 65 wk of age, respectively (P < 0.01). Correlations between breeder age and myristic acid and linoleic acid (r = -0.317 and -0.435, respectively) were significant when data were pooled from 28 to 65 wk of age. Significant correlations between H/F and myristic acid and linoleic acid were determined. The correlation between F and linoleic acid (r = 0.364; P < 0.05) was found to be significant with the change of breeder age. There were negative correlations between late embryonic mortality and myristic acid (r = -0.432; P < 0.05), stearic acid (r = -0.437; P < 0.05), and linoleic acid (r = -0.469; P < 0.5) at 28 to 65 wk of age. The findings from this study will contribute to the hatcheries of the poultry sector and the new studies that are going to be carried out. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the effect of live weight, male to female ratio and breeder age on egg weight and the hatching characteristics in Japanese quails (Coturnix coturnix japonica). Female quails at the age of six weeks, were weighed individually and separated into three weight groups depending on their live weights. The groups were classified as light (170-200 g), medium (201-230 g) and heavy (> 230 g). The male quails to be mated with these groups were selected from the individuals with mean live weight of 200-220 g. Groups were placed in the pens at male : female ratios of 1:1, 1:2, 1:3, 1:4 and 1:5. Egg weight was significantly lower in the light group compared with the eggs obtained from the females with medium and heavy live weight. Egg weight increased in accordance with increasing breeder age. Live weight, male to female ratio and breeder age had a significant effect on fertility and hatchability. Fertility increased with an increase in live weight. The highest fertility was found in the group with male to female ratios of 1:2 and 1:3. Fertility at the ages of 11-14 and 15-18 weeks was higher than those of 7-10 and 19-22 weeks of age. [ABSTRACT FROM AUTHOR]

Presents information on a study which determined the effect of storage position and storage temperature conditions on embryonic mortalities in ostrich eggs. Trial on storage temperature conditions; Storage position treatments; Effects of storage time on the hatchability of ostrich eggs.

We present diffuse x-ray scattering data on the strong negative thermal expansion (NTE) material ScF3 and find that two-dimensional nanoscale correlations exist at momentum-space regions associated with possibly rigid rotations of the perovskite octahedra. We address the extent to which rigid octahedral motion describes the dynamical fluctuations behind NTE by generalizing a simple model supporting a single floppy mode that is often used to heuristically describe instances of NTE. We find this model has tendencies toward dynamic inhomogeneities and its application to recent and existing experimental data suggest an intricate link between the nanometer correlation length scale, the energy scale for octahedral tilt fluctuations, and the coefficient of thermal expansion in ScF3. We then investigate the breakdown of the rigid limit and propose a resolution to an outstanding debate concerning the role of molecular rigidity in strong NTE materials. [ABSTRACT FROM AUTHOR]

Simple cubic 'open' perovskite ScF 3 stands out among trifluoride materials in its large, isotropic negative thermal expansion (NTE), but also its proximity of its zero-temperature state to a structural phase transition. Here we report a temperature- and frequency-dependent lattice dynamical study of Brillouin zone center lattice excitations of single crystals of ScF 3 using infrared reflectivity measurements. In addition to quantifying the mode strengths and energies in single crystals of this interesting material, we also find strong evidence for multiphonon absorption processes which excite the zone-edge incipient soft modes associated with NTE and the structural quantum phase transition. In this way, we identify an optically-allowed pathway to excite soft modes provides a means to athermally populate modes associated with NTE in ScF 3 .

1. The object of this research was to investigate the effects of high altitude with supplementary oxygen during the last stage of incubation of broiler eggs laid at low altitude and incubated at low and high altitude. We analysed thyroid hormones and haematological variables. 2. The treatment groups were: low altitude (LA), high altitude with oxygen supplementation in the hatcher (HA-OX) and high altitude non-oxygen-supplemented (HA-NOX). 3. High altitude affected relative egg weight loss and early embryonic mortality. The hatchability of fertile eggs was lower at high than at low altitude. 4. Oxygen supplementation into the hatcher cabinet during the last stage of incubation decreased late embryonic mortality ratio (LEM(1)) and improved survival rates of embryos incubated at high altitude. 5. Eggs incubated at low altitude had a higher hatched chick weight and relative chick weight than those incubated at high altitude. Hatched chick weight and relative chick weight did not change with oxygen supplementation at high altitude. 6. High altitude caused an increase in plasma T(3) and T(4) concentrations as well as in the ratio of T(3):T(4) in embryos. High altitude newly hatched chicks showed a higher T(3):T(4) ratio than low altitude chicks; this ratio decreased with oxygen supplementation at high altitude. Altitude and oxygen supplementation did not affect the mean plasma T(4). 7. Newly-hatched chicks incubated at high altitude showed a higher plasma haematocrit (PCV) than the newly-hatched chicks from eggs incubated at low altitude. High altitude without supplementation increased haemoglobin (Hb), while oxygen supplementation returned the value to low altitude values.

(1) This research was carried out to investigate changes in egg production and hatchability as influenced by age and breeding season of 10 trios (two females, one male) of ostrich (Struthio camellus) during 1998 to 2002. (2) Breeding season affected number of eggs laid per female per season, average egg weight, length of laying period and clutch sequence. (3) The number of eggs laid per female per season was 25 in the first breeding season and 57 by the fifth breeding season. The laying period lasted 169 d in the first season whereas it was 210 d by the fifth season. The breeding season became longer year by year. (4) The number of clutches was two in the first season, three in the second and 4 in the later breeding seasons: the mean interval between cycles was 9 to 10.6 d and the mean number of eggs in one cycle varied from 12 to 14.4. (5) The breeding season affected the hatchability of fertile eggs, chick weight at hatching, hatchability of total eggs, fertility, malpositioned embryos, deformed chicks and assisted chicks during hatching. The first 4 variables increased and the last three decreased, with each breeding season. (6) Weight loss of eggs and length of incubation were unaffected by the breeding season. Hatchability which was 64.3% in the first season increased progressively and reached 73.1% in the fifth breeding season.

1. This study was conducted to examine some egg characteristics and determine the effects of eggshell thickness and eggshell porosity on water loss and hatchability of eggs in ostriches. 2. Shell thickness did not correlate significantly with hatchability. However, eggs of low shell thickness lost more mass (13.03%) than those with intermediate (11.22%) and high (10.36%) shell thickness. Mass loss during incubation was higher in hatched (11.98%) than unhatched eggs (11.09%). Shell thickness was negatively correlated to egg mass loss (r = -0.65). 3. The pore density was correlated with hatchability. Hatchability was 50% lower in eggs with low pore densities (40.93%) than with high densities (80.94%). Pore density was positively correlated with egg mass loss (r = 0.63). Incubation mass losses of hatched and unhatched eggs were not significantly different. 4. Mean eggshell water vapour conductance (G) value and shell conductance constant (k) were 87.77 +/- 4.21 mg H2O/d/Torr and 2.44 respectively (n = 15). 5. Because of eggshell functional properties and resulting low egg mass loss hatchability is low when ostrich eggs are artificially incubated. The mass of eggs used in the experiment was relatively high and their eggshell water vapour conductance was low. As a result, egg incubation mass loss was lower than it should be. It is concluded that incubator humidity should be low (25%) to allow enough mass loss during incubation from the eggs.