bluuebunny/crossref_metadata_2025 huggingface dataset:
A dynamic global radio frequency noise survey as observed by the FORTE satellite at 800 km altitude
Authors: Burr Tom , Jacobson Abram , Mielke Angela
Published: December 2005

Detecting transient events in noisy time series is complicated by several issues. We focus on the issue of nonstationary noise, illustrate an approach (“dynamic” strategy) on radio frequency (RF) observations from the FORTE satellite that frequently updates the estimated background, and provide a dynamic survey of FORTE noise. The performance measure is the distribution of R2/, where R2 is the squared noise amplitude at a given frequency and is the most recent mean squared amplitude. The definition of “most recent” ranges from 10 μs to 10 s. We also vary the fraction of the update period used to compute the mean from 0.1% to 100% of the previous period. For FORTE, we define 13 geographic regions and analyze signal‐free records (assumed to be representative of the noise, but discussion is provided). The best dynamic case is compared to a static strategy that uses R2/static, where static is the mean over a period that covers tens of days (tens of days is the time required for the variance of the noise to reach its maximum). It is shown that some type of dynamic strategy has better statistical sensitivity than the static strategy. This survey illustrates one way to select an “update‐the‐mean” strategy that is applicable in many settings. We also describe a multiband triggering method, which together with the update‐the‐mean strategy helps establish the lower limit of detection of signals of interest, for example, in the case of FORTE, in satellite‐based long‐baseline radio astronomy and in cosmic ray shower RF emissions.
Exhumation of the Ailao Shan shear zone recorded by Cenozoic sedimentary rocks, Yunnan Province, China
Authors: Schoenbohm Lindsay M. , Burchfiel B. Clark , Liangzhong Chen , Jiyun Yin
Published: December 2005

The role of strike‐slip faults, such as the Ailao Shan shear zone in southwestern China, in accommodating the India‐Eurasia collision remains controversial. Cenozoic sedimentary rocks preserved along the northeast side of the Ailao Shan shear zone, however, record the nature and timing of exhumation of shear zone rocks. Field mapping shows that the lower strata consist of early Oligocene lacustrine red mudstone and gypsum and the upper of late Oligocene to Miocene fluvial conglomerate with rare, fine‐grained, fossil leaf‐bearing intervals. Sediment derived from shear zone gneiss is present only in the upper part of the section. Our observations indicate deformation began in Oligocene time, with the onset of rapid exhumation by early Miocene time, consistent with existing geochronologic results. Exhumation must have ended before the formation of a regional low‐relief erosion surface and the onset of brittle deformation along the Red River fault, probably in early Pliocene time. Rapid exhumation of the Ailao Shan shear zone has been interpreted to have occurred in transtension, accommodated by a normal fault on the northeast margin of the shear zone. However, we observe consistent and pervasive shortening structures within the Cenozoic strata, including overthrusting and folding of the basin along faults defined by thick gouge zones within weak Cenozoic lithologies. Deformation is likely syndepositional. These structures are distinct from subvertical deformational features associated with the active Red River fault. Our field data thus support mid‐Cenozoic transpressional exhumation of the Ailao Shan shear zone. This is consistent with regional evidence for widespread left‐lateral and compressional deformation in the region to the east of the eastern Himalayan syntaxis during this time. Focused erosion along the Red River, established by late Oligocene time, may have contributed to deeper exhumation of the northeast part of the shear zone.
Scattering of traveling spots in dissipative systems
Authors: Nishiura Yasumasa , Teramoto Takashi , Ueda Kei-Ichi
Published: December 2005

One of the fundamental questions for self-organization in pattern formation is how spatial periodic structure is spontaneously formed starting from a localized fluctuation. It is known in dissipative systems that splitting dynamics is one of the driving forces to create many particle-like patterns from a single seed. On the way to final state there occur many collisions among them and its scattering manner is crucial to predict whether periodic structure is realized or not. We focus on the colliding dynamics of traveling spots arising in a three-component system and study how the transition of scattering dynamics is brought about. It has been clarified that hidden unstable patterns called “scattors” and their stable and unstable manifolds direct the traffic flow of orbits before and after collisions. The collision process in general can be decomposed into several steps and each step is controlled by such a scattor, in other words, a network among scattors forms the backbone for scattering dynamics. A variety of input-output relations comes from the complexity of the network as well as high Morse indices of the scattor. The change of transition manners is caused by the switching of the network from one structure to another, and such a change is caused by the singularities of scattors. We illustrate a typical example of the change of transition caused by the destabilization of the scattor. A new instability of the scattor brings a new destination for the orbit resulting in a new input-output relation, for instance, Hopf instability for the scattor of peanut type brings an annihilation.
Complex patterns in reactive microemulsions: Self-organized nanostructures?
Authors: Epstein Irving R. , Vanag Vladimir K.
Published: December 2005

In a reverse microemulsion consisting of water, oil (octane), an anionic surfactant [aerosol OT (AOT)], and the reactants of the oscillating Belousov-Zhabotinsky (BZ) reaction, a variety of complex spatiotemporal patterns appear. These include traveling and standing waves, spirals that move either toward or away from their centers, spatiotemporal chaos, Turing patterns, segmented waves, and localized structures, both stationary and oscillatory. The system consists of nanometer-sized droplets of water containing the BZ reactants surrounded by a monolayer of AOT, swimming in a sea of oil, through which nonpolar BZ intermediates can diffuse rapidly. We present experimental and computational results on this fascinating system and comment on possible future directions for research.
Glutamate-induced glutamate release: A proposed mechanism for calcium bursting in astrocytes
Authors: Larter Raima , Craig Melissa Glendening
Published: December 2005

Here we present a new model for the generation of complex calcium-bursting patterns in astrocytes, a type of brain cell recently implicated in a variety of neural functions including memory formation. The model involves two positive feedback processes, in which the key feedback species are calcium ion and glutamate. The latter is the most abundant excitatory neurotransmitter in the brain and has been shown to be involved in bidirectional communication between astrocytes and nearby neurons. The glutamate feedback process considered here is shown to be critical for the generation of complex bursting oscillations in the astrocytes and to, perhaps, code for information which may be passed from neuron to neuron via the astrocyte. These processes may be involved in memory storage and formation as well as in mechanisms which lead to dynamical diseases such as epilepsy.
Electronic structures of size-selected single-layered platinum clusters on silicon(111)-7×7 surface at a single cluster level by tunneling spectroscopy
Authors: Yasumatsu Hisato , Hayakawa Tetsuichiro , Kondow Tamotsu
Published: December 2005

Tunneling spectra of size-selected single-layered platinum clusters (size range of 5–40) deposited on a silicon(111)-7×7 surface were measured individually at a temperature of 77K by means of a scanning tunneling microscope (STM), and the local electronic densities of states of individual clusters were derived from their tunneling spectra measured by placing an STM tip on the clusters. In a bias-voltage (Vs) range from −3 to 3V, each tunneling spectrum exhibits several peaks assignable to electronic states associated with 5d states of a constituent platinum atom and an energy gap of 0.1–0.6eV in the vicinity of Vs=0. Even when platinum cluster ions having the same size were deposited on the silicon(111)-7×7 surface, the tunneling spectra and the energy gaps of the deposited clusters are not all the same but can be classified in shape into several different groups; this finding is consistent with the observation of the geometrical structures of platinum clusters on the silicon(111)-7×7 surface. The mean energy gap of ∼0.4eV drops to ∼0.25eV at the size of 20 and then decreases gradually as the size increases, consistent with our previous finding that the cluster diameter remains unchanged, but the number density of Pt atoms increases below the size of 20 while the diameter increases, but the density does not change above it. It is concluded that the mean energy gap tends to decrease gradually with the mean cluster diameter. The dependence of the mean energy gap on the mean Pt–Pt distance shows that the mean energy gap decreases sharply when the mean Pt–Pt distance exceeds that of a platinum metal (0.28nm).
Ultrahigh-density storage media prepared by artificially assisted self-assembling methods
Authors: Naito Katsuyuki
Published: December 2005

Two types of recording media possessing nanodot structures were investigated. The media were prepared by an artificially assisted self-assembling (AASA) method, which includes simple nanopatterning using a nanoimprint and fine nanopatterning using self-assembling organic molecules. One type of recording media is circumferential magnetic patterned media prepared on a 2.5-in.-diam glass plate. A Ni master disk possessing spiral patterns with 60–250 nm width lands and a 400 nm width groove was pressed to a resist film on a CoCrPt film to transfer the spiral patterns. A diblock copolymer solution was cast into the obtained grooves, and then annealed to prepare self-assembling dot structures aligned along the grooves. According to the dot patterns, the lower magnetic films were patterned by ion milling to yield patterned media with 40 nm diameter. We have also prepared FePt dot media with high magnetic anisotropy for near-field and magnetic-field hybrid recording aiming at more than 1Tb∕in.2 density. A Ni stamp disk with aligned dot structures was also prepared by the AASA method to produce patterned media at the lowest cost. The other type of media was organic patterned media for X-Y type near-field optical storage. Bulky dye molecules were evaporated in vacuum to produce self-assembling amorphous nanodots. The dots were arranged by the AASA method, i.e., according to the polymethylmethacrylate film hole arrays or chemically patterned surface.
Electric field and dewetting induced hierarchical structure formation in polymer/polymer/air trilayers
Authors: Leach K. Amanda , Gupta Suresh , Dickey Michael D. , Willson C. Grant , Russell Thomas P.
Published: December 2005

Electrohydrodynamics were studied in a trilayer thin film system consisting of two different polymeric layers and air. A polymer with a higher dielectric constant, poly(methyl methacrylate), was sandwiched between air and a lower dielectric constant polymer, polystyrene. An electric field was applied normal to the interfaces. Along with electrostatic forces, dewetting forces were significant at two of the interfaces, namely, the polystyrene/silicon wafer and the polystyrene/poly(methyl methacrylate) interfaces. These two combined forces produce novel closed-cell structures that are difficult to produce by other existing techniques.
Coupled-perturbed density-matrix functional theory equations. Application to static polarizabilities
Authors: Pernal Katarzyna , Baerends Evert Jan
Published: December 2005

Starting from the variational equations for the natural occupation numbers and the recently proposed eigenequations for the natural spin-orbitals, we derive coupled-perturbed density-matrix equations that furnish a linear response of the one-electron reduced density matrix to a static perturbation when the total energy is a functional of the one-electron reduced density matrix. Cases when some occupation numbers achieve exactly 0 or 1 or when the total number of the particles in a system is not preserved are taken into consideration. The scheme is applied to computing static polarizabilities from two simple density-matrix functionals. The behavior of the functionals is erratic and they provide only little or no improvement over the coupled-perturbed Hartree-Fock results.
Spontaneous formation of polymer nanoparticles by good-solvent evaporation as a nonequilibrium process
Authors: Yabu Hiroshi , Higuchi Takeshi , Ijiro Kuniharu , Shimomura Masatsugu
Published: December 2005

In recent years, polymer nanoparticles have been investigated with great interest due to their potential applications in the fields of electronics, photonics, and biotechnology. Here, we report the spontaneous formation of polymer nanoparticles from a clear solution containing a nonvolatile poor solvent by slow evaporation of a volatile good solvent. During evaporation of the good solvent, the solution gradually turns turbid. After evaporation, polymer nanoparticles of homogeneous shape and size are dispersed in the poor solvent. Homogeneous nucleation and successive growth of polymer particles takes place during the dynamic nonequilibrium process of solvent evaporation. The size of the particles, ranging from tens of nanometers to micrometer scale, depends on both polymer concentration and the solvent mixing ratio. Because of the physical generality of the particle formation mechanism, this procedure is applicable to a wide variety of polymers with suitable combinations of solvents. Here, we also show unique features, surface structures and surface properties of polymer nanoparticles prepared by this method.
Exchange-hole dipole moment and the dispersion interaction: High-order dispersion coefficients
Authors: Becke Axel D. , Johnson Erin R.
Published: December 2005

In recent publications [A. D. Becke and E. R. Johnson, J. Chem. Phys. 122, 154104 (2005); E. R. Johnson and A. D. Becke 123, 024101 (2005)] we have demonstrated that the position-dependent dipole moment of the exchange hole can be used to generate dispersion interactions between closed-shell systems. Remarkably accurate C6 coefficients and intermolecular potential-energy surfaces can be obtained from Hartree-Fock occupied orbitals and polarizability data alone. In the present work, our model is extended to predict C8 and C10 coefficients as well. These higher-order coefficients are obtained as easily as C6 and with comparable accuracy.
Transport in polymer-gel composites: Response to a bulk concentration gradient
Authors: Hill Reghan J.
Published: December 2005

This paper examines the response of electrolyte-saturated polymer gels, embedded with charged spherical inclusions, to a weak gradient of electrolyte concentration. An electrokinetic model was presented in an earlier publication, and the response of homogeneous composites to a weak electric field was calculated. In this work, the influence of the inclusions on bulk ion fluxes and the strength of an electric field (or membrane diffusion potential) induced by the bulk electrolyte concentration gradient are computed. Effective ion diffusion coefficients are significantly altered by the inclusions, so—depending on the inclusion surface charge or ζ potential—asymmetric electrolytes can behave as symmetrical electrolytes and vice versa. The theory also quantifies the strength of flow driven by concentration-gradient-induced perturbations to the equilibrium diffuse double layers. Similarly to diffusiophoresis, the flow may be either up or down the applied concentration gradient.
Entropy production in a two-dimensional reversible Gray-Scott system
Authors: Mahara Hitoshi , Yamaguchi Tomohiko , Shimomura Masatsugu
Published: December 2005

The entropy production σ is calculated in the time evolution processes toward a Turing-like pattern and a chaotic pattern in a two-dimensional reaction-diffusion system. The contributions of reaction and diffusion to the entropy production are evaluated separately. Though its contribution to total σ is about 5%, the entropy production in diffusion foretells the moving direction of the dots (reaction spots) and the line-shaped patterns. The entropy production of the entire system σ¯ depicts well the cooperative dynamics and evolution of chaotic dot patterns. It is suggested that σ¯ can be a scalar measure for quantitative studies of hierarchic pattern dynamics. The relation is also discussed between the bifurcation parameter and the distance from thermodynamic equilibrium.
Implementation of a modern resonant ultrasound spectroscopy system for the measurement of the elastic moduli of small solid specimens
Authors: Migliori Albert , Maynard J. D.
Published: December 2005

The use of mechanical resonances to determine the elastic moduli of materials of interest to condensed-matter physics, engineering, materials science and more is a steadily evolving process. With the advent of massive computing capability in an ordinary personal computer, it is now possible to find all the elastic moduli of low-symmetry solids using sophisticated analysis of a set of the lowest resonances. This process, dubbed “resonant ultrasound spectroscopy” or RUS, provides the highest absolute accuracy of any routine elastic modulus measurement technique, and it does this quickly on small samples. RUS has been reviewed extensively elsewhere, but still lacking is a complete description of how to make such measurements with hardware and software easily available to the general science community. In this article, we describe how to implement realistically a useful RUS system.
Nonvolatile phase change memory nanocell fabrication by femtosecond laser writing assisted with near-field optical microscopy
Authors: Wang W. J. , Zhao R. , Shi L. P. , Miao X. S. , Tan P. K. , Hong M. H. , Chong T. C. , Wu Y. H. , Lin Y.
Published: December 2005

The phase change memory cells were developed by using a combination system of a femtosecond laser with near-field scanning optical microscopy. The memory cells with feature size varying from 800nm down to 90nm were achieved. The cell functional performances were tested, and the scalability of the programming current as a function of the memory cell features was investigated. The optical near-field distance which is one of the critical factors to achieve high resolution nanostructures was studied experimentally with the consideration of the whole fabrication process for functional devices. The Bethe-Bouwkamp model was employed to study the effects of the optical near-field distance to the nanostructure geometry. The programming current of 0.8mA was observed for the memory nanocell at a feature size of 90nm.
A mode coupling theory description of the short- and long-time dynamics of nematogens in the isotropic phase
Authors: Li Jie , Cang Hu , Andersen Hans C. , Fayer M. D.
Published: December 2005

Optical heterodyne-detected optical Kerr effect (OHD-OKE) experimental data are pre-sented on nematogens 4-(trans-4′-n-octylcyclohexyl)isothiocyanatobenzene (8-CHBT), and 4-(4′-pentyl-cyclohexyl)-benzonitrile (5-PCH) in the isotropic phase. The 8-CHBT and 5-PCH data and previously published data on 4′-pentyl-4-biphenylcarbonitrile (5-CB) are analyzed using a modification of a schematic mode coupling theory (MCT) that has been successful in describing the dynamics of supercooled liquids. At long time, the OHD-OKE data (orientational relaxation) are well described with the standard Landau-de Gennes (LdG) theory. The data decay as a single exponential. The decay time diverges as the isotropic to nematic phase transition is approached from above. Previously there has been no theory that can describe the complex dynamics that occur at times short compared to the LdG exponential decay. Earlier, it has been noted that the short-time nematogen dynamics, which consist of several power laws, have a functional form identical to that observed for the short time behavior of the orientational relaxation of supercooled liquids. The temperature-dependent orientational dynamics of supercooled liquids have recently been successfully described using a schematic mode coupling theory. The schematic MCT theory that fits the supercooled liquid data does not reproduce the nematogen data within experimental error. The similarities of the nematogen data to the supercooled liquid data are the motivation for applying a modification of the successful MCT theory to nematogen dynamics in the isotropic phase. The results presented below show that the new schematic MCT theory does an excellent job of reproducing the nematogen isotropic phase OHD-OKE data on all time scales and at all temperatures.
Development of microcoulometry for measuring oxygen content in copper oxides
Authors: Sato Fumiaki , Fujihara Masaaki , Komiyama Naokazu , Kambe Shiro , Ishii Osamu
Published: December 2005

A microcoulometry system was developed and employed for measuring the oxygen content in copper oxides using a reduced amount of material. To achieve this reduction in sample size, Ar flow rate, and coulometric current were optimized. When using 5.0 mg of YBa2Cu3O6.71, which is about one-tenth of the amount used in conventional coulometry, the oxygen content was determined to be 6.68±0.03 in the optimized conditions that Ar flow rate, and coulometric current were 0.1l∕min and 1.0 mA, respectively. This method will be useful for measuring the oxygen content of oxide samples smaller than 10 mg, i.e., oxide materials produced in small quantities for electronic applications.
A de Finetti representation for finite symmetric quantum states
Authors: König Robert , Renner Renato
Published: December 2005

Consider a symmetric quantum state on an n-fold product space, that is, the state is invariant under permutations of the n subsystems. We show that, conditioned on the outcomes of an informationally complete measurement applied to a number of subsystems, the state in the remaining subsystems is close to having product form. This immediately generalizes the so-called de Finetti representation to the case of finite symmetric quantum states.
Theory of simultaneous control of orientation and translational motion of nanorods using positive dielectrophoretic forces
Authors: Edwards Brian , Engheta Nader , Evoy Stephane
Published: December 2005

The manipulation of individual submicron-sized objects has been the focus of significant efforts over the last few years. A method to arbitrarily move and orient a set of rod-shaped conductive particles in a region defined by a set of electrodes using positive dielectrophoretic forces is presented. While the orientation of each particle is directly specified through the angle of the local electric field, its position is indirectly controlled through the applied force. Each electrode is approximated as an unknown point charge and an induced dipole. Since each induced dipole results from the combination of all other sources, a set of linear constraints are derived to enforce the self-consistency of the system. Additionally, the force and orientation of each particle also form an additional set of linear constraints. This combined set of constraints is then solved numerically to yield the sources required to induce the desired orientation and motion of each particle. It is observed that the minimum number of electrodes that can be used to control a set of N particles is 4N+1. Numerical simulations demonstrate that the control of a single nanorod (diameter of 70nm; length of 1.4μm) in the midst of a realistic electrode array can be accomplished under practical conditions. In addition, such control of orientation and motion can be achieved over an ample region in the vicinity of each rod.
Recombination profiles in poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] light-emitting electrochemical cells
Authors: Leger J. M. , Carter S. A. , Ruhstaller B.
Published: December 2005

We present a study on the optical and electronic properties of light-emitting electrochemical cells (LECs) based on poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) with the goal of understanding emission profiles and characterizing salt and electrode dependence. Direct imaging of photoluminescence and electroluminescence profiles of planar LECs and simulations of optical interference effects were performed in order to gain insight into emission profiles in vertical structure LECs. While our results are consistent with oxidative doping, they imply a lack of reductive doping in LECs under normal operating conditions. We observe that trends in emission profiles are independent of thickness, salt, and electrode type. In addition, device current-voltage (I-V) and radiance characteristics were measured as a function of salt and electrode type. Variations in the I-V characteristics, turn-on voltage, and rectification are observed for devices with Al versus. Au contacts and for salts with varied cation type. Finally, we discuss the implications of our findings on the operating mechanism of LECs.
Magnetic properties of superparamagnetic lithium ferrite nanoparticles
Authors: Verma Seema , Joy P. A.
Published: December 2005

Magnetic properties of lithium ferrite nanoparticles of size in the range of 4–50nm, synthesized by a low-temperature method, have been evaluated. A broad maximum at ∼220K in the temperature variation of the zero-field-cooled magnetization as well as the ac susceptibility and divergence of the zero-field-cooled and field-cooled magnetizations below this temperature indicate the superparamagnetic behavior of the lithium ferrite particles of size ∼4nm. On the other hand, at high temperatures, these particles show a cusp immediately below the Curie temperature of bulk lithium ferrite (895K). This anomalous magnetic behavior of the lithium ferrite nanoparticles, similar to that arising from the Hopkinson effect for bulk materials, is probed in detail and is explained in terms of the cumulative effect of the temperature variation of the anisotropy and particle size growth during the measurements at high temperatures.
Effect of distorted illumination waves on coherent diffraction microscopy
Authors: Kohmura Yoshiki , Nishino Yoshinori , Ishikawa Tetsuya , Miao Jianwei
Published: December 2005

Coherent diffraction microscopy requires a well-defined illumination wave such as a plane wave on a specimen. Experimentally, a small pinhole or a focused beam is often used to reduce the illumination area but they unavoidably distort the waves. The distortion of the illumination wave causes artifacts in the phase retrieval of oversampled diffraction patterns. Using computer simulations, we searched for the conditions where strong artifacts arise by changing the Fresnel number, pinhole size, alignment error and photon statistics. The experimental setup with Fresnel number of around 1 and smaller than 1 realized a small reconstruction error when the pinhole radius is larger than a few times the specimen size. These conditions are suitable for the rotation of specimens for the three-dimensional (3D) observations. Such investigation will have an impact in the design of coherent diffraction microscopes for the 3D characterization of nanoscale materials and biological systems using the third generation synchrotron radiation and future x-ray free-electron lasers.
Simultaneous microRaman and synchrotron radiation microdiffraction: Tools for materials characterization
Authors: Davies R. J. , Burghammer M. , Riekel C.
Published: December 2005

MicroRaman (μRaman) and x-ray microdiffraction (μXRD) are complementary techniques, ideally suited to simultaneous combination. They provide quite different structural information, across a range of different length scales. This letter reports on a simultaneous μRaman∕μXRD experiment. The laser and x-ray beams are delivered coaxially and simultaneously to the same point on the sample. To demonstrate the technical capabilities of the system, data are presented from a structured silicon/tantalum sample. The distributions of Si and Ta are given by the intensities of the 520cm−1 Raman band and the 002 reflection of the Ta β-phase, respectively. The combination of these two techniques is a powerful tool for materials characterization.
Kinetics of irradiation-induced Cu precipitation in nuclear reactor pressure vessel steels
Authors: Nagai Y. , Toyama T. , Nishiyama Y. , Suzuki M. , Tang Z. , Hasegawa M.
Published: December 2005

The followup of the embrittlement of nuclear power reactor pressure vessels (RPVs) is of critical importance for the safety assessment in the nuclear industry. The prediction of their future degradation is based on the extrapolation of the past testing of surveillance materials irradiated in the power reactor and in material testing reactors with accelerated dose rates. Using positron annihilation spectroscopy, however, we here reveal a kinetics of irradiation-induced precipitation, i.e., very low dose rate can significantly enhance Cu nanoprecipitation. The mechanism results in the embrittlement in practical RPVs, occurring at a much earlier stage than that found from accelerated tests, suggesting that accelerated tests are not enough for prediction of the embrittlement from Cu nanoprecipitation.
Metamorphic buffers and optical measurement of residual strain
Authors: Geddo M. , Guizzetti G. , Patrini M. , Ciabattoni T. , Seravalli L. , Frigeri P. , Franchi S.
Published: December 2005

We show that the residual strain occurring in constant-composition metamorphic buffer layers of III–V heterostructures can be accurately predicted by the suitable design of the epitaxial structures and measured all optically by means of photoreflectance spectroscopy. This result allows one to single out the nonequilibrium models among those that have been proposed to predict strain relaxation. The resulting ∝t−1∕2 dependence of the residual in-plane strain on buffer thickness t can be used to design metamorphic buffers not only for 1.3–1.55μm emitting quantum dot structures, but also for sophisticated graded-composition metamorphic structures for different classes of devices.
Feeding behaviour of Merino wethers under conditions similar to lot-feeding before live export
Authors: McDonald CL , Norris RT , Speijers EJ , Ridings H
Published: December 2005

Sheep from different farms (lines) in Western Australia were mixed in 3 experiments and lot-fed for 6-7 days as if for export. A marking method to identify sheep which eat from troughs was tested and used to examine the effects of feeding treatments on the proportion of sheep which eat during lot-feeding. Paint soaked sponges attached to troughs were used to monitor whether sheep ate. Positive linear relationships between liveweight change and paint marking score (R = 0.93, 0.93 and 0.94, in the 3 experiments) suggested that the technique was a reliable indicator of feed intake. Feeding treatments imposed were period of fasting before lot feeding (experiments 2 and 3); and diet type (hay pellets, hay/pellet mix) and trough location in the feedlot (experiment 3). There were large differences between lines in the percentage of sheep not marked. Values � s.e. ranged from 1 � 1 to 79 � 3% for the 8 lines used in 3 experiments. In experiment 2, fasting for 48 h before lot-feeding resulted in more sheep (P<0.05) not marked (18 � 7 3%) than did fasting for <12 h (9 � 3%) and <24 h (8 � 2%). In experiment 3, fasting for 96 h compared with 48 h resulted in fewer sheep marked daily when fed a hay-pellet mixture (75 � 2 v. 93 � 1%; P<0.001). When fed only pellets in experiment 3, the percentages of marked sheep increased with time (days). Feeding pellets only compared with a hay-pellet mixture resulted in fewer sheep marked daily (60 � 2 v. 79 � 2%; P<0.001) and more sheep not marked (11 � 3 v. 3 � 2%; P<0.05). If troughs were located in the centre of yards instead of on the fenceline, it took 2 rather than 7 days for the daily percentage of animals marked on the pellets only diet to exceed 80%. The central location also resulted in a mean of 78 � 2% of sheep marked daily compared with 67 � 2% for fenceline troughs (P<0.001) and a mean intake higher (P<0.01) by 0.13 � 0.04 kg/wether.day. It was concluded that line of sheep, fasting, diet and trough location all had significant effects on feeding behaviour during lot feeding. Of these treatments, the greatest variation in feeding behaviour was associated with the line of sheep.
Effect of age of beak trimming on the production performance of hens
Authors: Glatz PC
Published: December 2005

The effect of age at beak trimming (at hatch, or 10 or 42 days) on the production performance of 2 Australian commercial laying strains (brown egg and a tinted egg layer) was assessed by measuring egg production, food intake, food efficiency, egg weight, egg gradings and body weights of chickens from 19 to 82 weeks of age. Beak trimming removed one half of the upper beak and one third of the lower beak from birds. The tinted egg strain trimmed at hatching was the most efficient of all treatment groups. Layers not trimmed consumed significantly more food, laid fewer eggs and had poorer food efficiency than beak trimmed birds. Early in lay there was no difference in daily egg production with age at beak trimming, but by 50 weeks of age, birds trimmed at hatching or 42 days were producing more eggs than those trimmed at 10 days of age. Chickens trimmed at hatching consumed less food than chickens trimmed at 10 days, and in the late laying phase (67-82 weeks) all beak trimmed groups had significantly lower food intake than control hens. These results show that age of beak trimming influences performance and that considerable saving in food costs for the Australian Poultry Industry can be achieved by trimming half of the top beak and one third of the bottom beak of chickens at hatching.
The effect of defoliation interval in winter on pasture productivity in winter and spring: a regional comparison
Authors: Belton JM
Published: December 2005

Forty-five plots (3 by 2 m) of perennial ryegrass-white clover pasture were randomly allocated within 3 sites to 5 winter defoliation interval treatments to determine the effect of site on best defoliation interval as measured by winter and spring herbage accumulation. Defoliation intervals were 14, 28, 42, 56, and 84 days. The defoliation intervals resulting in maximum total winter dry matter (DM) accumulation at sites 1 and 3 were 42, 56 and 84 days. Available feed accumulated at the end of winter was highest for the 84-day defoliation interval at both sites (2.0 and 1.4 t DM/ha, respectively). At site 2, maximum total winter DM accumulation was achieved for defoliation intervals of 28, 42 and 56 days. Available feed accumulation at the end of winter was 1.2 t DM/ha for the 42-day interval and did not increase thereafter. The difference in response was associated with pasture composition. The results of the experiment showed that there is scope for flexibility in winter grazing management to suit livestock requirements without compromising total winter dry matter accumulation.
Distribution, severity and economic importance of powdery mildew of barley in Western Australia
Authors: Chan KC , Boyd WJR , Khan TN
Published: December 2005

Surveys of 112 commercial barley crops, yield loss experiments, and the assessment of 20 disease nurseries and 41 regional trials, from 1981 to 1986, showed that barley mildew is endemic throughout the agricultural areas of Western Australia, but seldom develops to epidemic proportions. Infection was common at the seedling stage with considerable variation in severity between and within farmers' fields, regions and seasons. The occurrence and severity of infection increased during the period of tiller production, but seldom developed further once tiller elongation commenced. The frequency with which severe infection persisted to anthesis was low and, with variation between seasons, was mainly confined to areas of extended growing season along the south coast. Infection of up to 70% leaf area damage resulted in a 40-60% reduction in grain yield. This reduction was due to reduced fertile tiller number if infection was severe during tiller production, or to reduced grain size and number if infection was severe at ear emergence and over grain filling. The overall economic importance of powdery mildew, however, is low even though the destructive potential of the disease can be high in some regions in some seasons.
Agronomic studies on the productivity of kenaf (Hibiscus cannabinus L. cv. Guatemala 4) under rainfed and irrigated conditions in the Northern Territory
Authors: Muchow RC , Sturtz JD , Spillman MF , Routley GE , Kaplan S , Martin CC , Bateman RJ
Published: December 2005

Field experiments were conducted at Berrimah, Douglas Daly and Katherine in the Northern Territory (NT) during the 1987-88 and 1988-89 wet seasons to obtain yield data for kenaf (Hibiscus cannabinzis L. cv. Guatemala 4) grown under rainfed and irrigated conditions. Under rainfed conditions, maximum stem yield was obtained from sowings early in the wet season. Yield decreased with delay in sowing until the late-December-January period. The maximum rainfed stem yield at Katherine in an above-average rainfall season was 18 400 kg/ha. The maximum yield in a below average rainfall season was 11 700 kg/ha at Katherine, 9200 kg/ha at Douglas Daly and 9400 kg/ha at Berrimah. The applicability to the NT of growth and yield relationships established for irrigated kenaf in the Ord Irrigation Area (OIA) was assessed. The yield potential under irrigated conditions in the NT (21 600 kg/ha at 131 days after sowing) was higher than that reported elsewhere in Australia for the same growth period, but similar to that reported elsewhere for longer growth duration (180-300 days). In the NT, in contrast to the OIA, stem yield showed little or no response to N fertilisation. Stem yield was not related to N uptake, and at high levels of N application, there was marked N accumulation in the stem. Kenaf was able to accumulate up to 110 kg N/ha from the soil reserve where no N was applied. The yield response to plant density varied with the yield level and was similar to that in the OIA. Bark and core yield could be estimated directly from biomass, and indirectly from stem length and plant density, over a wide range of yield levels and cultural conditions. It was concluded that data relating to yield potential and response to N fertilisation cannot be transferred directly from the OIA to the NT.
Effect of lime application to strongly acidic soils on the growth of macadamia seedlings
Authors: Aitken RL , Stephenson RA , Gallagher EC
Published: December 2005

Glasshouse experiments were undertaken to evaluate the effects of soil pH on macadamia (Macadamia integrifolia Maiden and Betche) seedlings and to examine seedling growth in relation to soil chemical properties in acidic soils. In one experiment, in which 13 rates of CaCO3 (0 to the equivalent of 12 000 kg/ha) were applied to a strongly acidic (pH 3.9, 1:5 in water) sandy loam, optimum seedling growth was obtained in the pH range 4.0-5.9. A second experiment, in which seedlings were grown in each of 3 strongly acidic soils amended with various rates of CaCO3, also showed that macadamia seedlings could grow satisfactorily at pH values of 4.0 (2 soils) and 4.5 (1 soil). Increased seedling growth on 2 soils (silty clay loam, experiment 1; sandy loam, experiment 2) treated with lime was due to amelioration of aluminium and/or manganese toxicity and not to the alleviation of calcium deficiency. The results indicate that soil pH measurement alone would not be a good indicator of seedling growth. In some soils, seedling growth was optimum at pH 3.9, whereas at pH 4.0 in another soil, growth was well below the maximum which was attained at pH 4.5. The significant (P<0.05) growth reductions that occurred on all soils limed to pH values >6.0 were attributed to induced micronutrient deficiencies.
Effect of cobalt and silver ions and naphthaleneacetic acid on fruit retention in mango (Mangifera indica L.)
Authors: Naqvi SSM , Alam SM , Mumtaz S
Published: December 2005

The effect of aqueous spray of cobalt nitrate, silver nitrate or 1-naphthaleneacetic acid (NAA) on fruit retention in mango (Mangifera indica L.) was investigated at Tando Jam, Pakistan. The chemicals were applied to immature fruits at pea size (5-6 mm) and again 2 weeks later when the fruitlets had developed to marble size (10-15 mm). Three cultivars, Sindhri, Langra (3 seasons) and Dasehari (4 seasons), were tested and it was observed that all concentrations of the chemicals significantly (P<0.05) increased fruit retention. In Sindhri, cobalt nitrate, silver nitrate and NAA treatments increased yields by 106-165%, 89-146% and 94-115%, respectively, and in Langra by 100-135%, 98-138% and 95-118%. Whole tree sprays of cv. Dasehari with Co(NO3)2 at 100 mg/L, AgNO3 at 100 mg/L, and NAA at 20 mg/L yielded 129%, 66% and 54% more fruit than the control.
Elliotdale and crossbred lambs: growth rate, wool production, fat depth, saleable meat yield, carcass composition and muscle content of selected cuts
Authors: Hopkins DL , Gilbert KD , Pirlot KL , Roberts AHK
Published: December 2005

Growth and carcass parameters were studied for 62 second-cross lambs (Poll Dorset rams over Border Leicester x Merino ewes) and 55 purebred Elliottdale lambs. Second cross lambs grew faster (P<0.001) from weaning to the first slaughter time than Elliottdale lambs and consequently weighed more and had heavier carcasses. Elliottdale lambs produced significantly (P<0.001) more wool between birth and weaning. The slope of the relationship between GR (tissue depth over the 12th rib 110 mm from the midline) and carcass weight was 1.24 � 0.23 mm/kg for second cross lambs and 0.82 � 0.17 mm/kg for Elliottdale lambs, indicating the latter lambs were leaner at heavier weights. Measures of subcutaneous fat depth at the 5th/6th and 12th/13th ribs were similar when carcass weight differences were considered for a subsample of 21 second cross and 26 purebred Elliottdale lambs. Subjective assessment of fat distribution and carcass conformation by 2 assessors revealed a significant (P<0.001) difference between breeds; second cross lambs having a better conformation. Saleable meat yield, carcass composition, and muscle content of several cuts were determined for a subsample of lambs. At a common side weight of 8 kg there was no significant difference in saleable meat yield. At this weight, crossbred lambs had a significantly (P<0.05) higher muscle content (505 g/kg) than Elliottdale lambs (480 g/kg). Fat content was similar at 300 g/kg with crossbred lambs having significantly (P<0.05) less bone (190 g/kg) than Elliottdale lambs (2 10 g/kg). The legs of carcasses from crossbred lambs were shown to contain significantly more muscle than those of Elliottdales (206 v. 195 g/kg). Carcass weight explained some of the variation in weight of leg and forequarter muscle (r2 = 0.63 and 0.61). This was improved by including an assessment for conformation from 1 assessor (r2 = 0.69 and 0.64). Eye muscle area at the 12th rib did not add significantly to the prediction; it was not different between breeds, nor was its depth to width ratio different between breeds. The pH measurements of the M. longissimus thoracis et lumborum were similar between breeds.
The effect of oral administration of methionine, bentonite, methionine/bentonite and methionine/oil homogenates on wool production of grazing and penned sheep in a semi-arid tropical environment
Authors: Cobon DH , Stephenson RGA , Hopkins PS
Published: December 2005

Penned and grazing sheep were supplemented in 3 experiments with either methionine (Me 2.5 g/sheep.day), bentonite (Bent 5 or 10 g), Me + Bent (1 : 2 and 1 : 4) or Me/oil homogenates. These supplements were added to the drinking water or in molasses-based licks for treatment periods of 4-6 weeks duration. The effects of supplements on wool growth, liveweight, and ammonia concentration in rumen liquor were determined. In experiment 1, penned sheep fed a maintenance diet (750 g/sheep.day) of pelleted lucerne and supplemented via the drinking water, showed increased (P<0.05) mean wool growth for the 4 treatment periods of 31% (Me + bent), 16% (Bent), 18% (Me/tallow) and 21% (Me). Factorial analysis revealed main effects of 12% for bentonite (P<0.05) and 17% for Me (P<0.01) supplements. In experiment 2, grazing sheep supplemented via the drinking water, increased (P<0.01) wool growth over 5 treatment periods by up to 32% (Me + bent), 15% (Bent), 20% (Me) and 26% (Me/oil). In experiment 3, penned sheep fed a maintenance diet of pelleted lucerne were supplemented with molasses licks containing Me, Bent, or Me + bent, mixed using either artesian bore water or rain water. No individual treatment effect on wool growth was recorded. However, factorial analysis revealed an 18% wool growth advantage (P<0.05) for bentonite supplements mixed in artesian bore water. Treatment had no consistent effect on liveweight of sheep or level of ammonia in rumen liquor. Responses in wool production to supplements were greatest when rumen ammonia values were >5 mg%. Considerable variation in apparent wool response occurred between treatments and treatment periods for both bentonite and methionine supplements. The greatest responses to methionine supplements occurred in experiments 1 and 2 when basal wool production in the control treatments was lowest. The homogenisation procedures used to prepare Me/oil supplements, did not demonstrate any consistent advantages in terms of extra wool response.
Yield and yield structure of triticales compared with wheat in northern New South Wales
Authors: Sweeney G , Jessop RS , Harris H
Published: December 2005

The yields and yield structure of cultivars of triticales and bread wheats (with a range of phasic development patterns in both species) were compared in 2 field experiments at Narrabri in northern New South Wales. The experiments were performed on a grey cracking clay soil with irrigation to prevent severe moisture stress. Triticales, both early and midseason types, appeared to have reached yield parity with well-adapted wheat varieties. Meaned over the 2 experiments and all sowings, the triticales yields were 19% greater than the bread wheats. Triticales were generally superior to wheat in all components of yield of the spike (1000-grain weight, grain number/spikelet and spikelet number/spike), whilst the wheats produced more spikes per unit area. The triticales also had higher harvest indices than the wheats. The results are discussed in relation to the overall adaptability of triticale for Australian conditions.
Zinc deficiency in wheat and lupins in Western Australia is affected by the source of phosphate fertiliser
Authors: Riley MM , Gartrell JW , Brennan RF , Hamblin J , Coates P
Published: December 2005

A long-term field experiment is being conducted in the wheatbelt of Western Australia to determine the effects of source of phosphate fertiliser on the residual effectiveness of zinc (Zn) to wheat and to sweet, narrow-leafed lupins grown in rotation. The initial 2 years' results of that experiment reported here indicate that both wheat and lupins responded to the addition of Zn to the soil. The requirements of these crops for Zn, can be mostly met with the small amount of Zn that is a natural component in single superphosphate manufactured from rock phosphates, but not with diammonium phosphate (DAP). The internal requirements for Zn of the aboveground tissues of lupins appear greater than those of wheat. Depending on the stage of growth, critical concentrations of Zn in the youngest leaf tissues of wheat that were prognostic of Zn deficiency, were found to vary from about 7 to 16 �g/g, while those in lupins were found to vary from about 28 to 37 �g/g.