154 research outputs found
Antiferromagnetic Coupling of Pr0.9RE0.1Ni (RE = Tb, Dy, Ho) Single Crystals
Magnetization and specific heat measurements were carried out on Pr0.9RE0.1Ni (RE = Tb,Dy, and Ho) single crystals. Spin rearrangements were observed along the c-axis ofsingle crystals with relatively small critical fields, Bc = 6.8, 4.0 and 2.6 T for RE = Tb,Dy and Ho, respectively. The magnetic phase transition temperatures, TM, were extracted from the specific heat data: TM = 22.7, 19.6 and 18.3 K with RE = Tb, Dy and Ho, respectively. The observed Bc values were used to estimate the heterogeneous (Pr-RE) exchange strength, and then calculate expected TM values, which were found to be close to the experimental ones. The present results of Bc and TM, together with the previous ones of Pr0.9Gd0.1Ni, were found to be consistent with the de Gennes rule
Biological data and model development for management of longfinned eels
Objectives:
1. Estimate population parameters required for a management model. These include survival, density, age structure, growth, age and size at maturity and at recruitment to the adult eel fishery. Estimate their variability among individuals in a range of habitats.
2. Develop a management population dynamics model and use it to investigate management options.
3. Establish baseline data and sustainability indicators for long-term monitoring.
4. Assess the applicability of the above techniques to other eel fisheries in Australia, in collaboration with NSW. Distribute developed tools via the Australia and New Zealand Eel Reference Group
Biological data and model development for management of longfinned eels
Objectives:
1. Estimate population parameters required for a management model. These include survival, density, age structure, growth, age and size at maturity and at recruitment to the adult eel fishery. Estimate their variability among individuals in a range of habitats.
2. Develop a management population dynamics model and use it to investigate management options.
3. Establish baseline data and sustainability indicators for long-term monitoring.
4. Assess the applicability of the above techniques to other eel fisheries in Australia, in collaboration with NSW. Distribute developed tools via the Australia and New Zealand Eel Reference Group
Time Dependent Magnetization of an Al-1.6%Mg₂Si Alloy
New observations of time dependent magnetization of an Al-1.6%Mg2Si alloy over a range of constant temperatures between 250 K and 310 K are presented. The post solution heat treatment time variations of magnetization at 300 and 310 K increased with time out to about 1300 minutes, whereas those at 280 and 290 K showed minima around 150 and 50 minutes, respectively. The magnetization at 250 K initially decreased slightly and then became constant with time. The observed time variations of magnetization are explained in terms of clustering reactions of the Mg, Si and vacancies
Temperature-dependent electrical, elastic and magnetic properties of sol-gel synthesized Bi 0.9 Ln 0.1 FeO 3 (Ln = Nd, Sm)
This report details correlated electrical, mechanical and magnetic behaviour in BiFeO3 ceramics doped with 10% Ln (Ln=Sm, Nd) ions on the Bi, or perovskite A, site and synthesized by a solgel method. The ceramics exhibit bulk piezoelectric and ferroelectric properties and clear ferroelectric domain patterns through piezoresponse force microscopy. Resonant ultrasound spectroscopy, dielectric spectroscopy and magnetometry studies show correlated magnetoelectromechanical behaviour and the existence of weak ferromagnetism for both compositions. An anomaly with simultaneous mechanical and magnetic signatures is discovered in both materials near room temperature, while previously reported transitions and anomalies are found to exhibit electro-and/or magnetomechanical coupling. Magnetism is significantly enhanced in the Sm doped sample, which is a promising multiferroic material
5th joint international conference on hyperfine interactions and symposium on nuclear quadrupole interactions (HFI/NQI 2014)
Early Stage Clustering Behavior in Al-Mg-Si Alloys Observed via Time Dependent Magnetization
Time dependent magnetization of Al-0.67 at.%Mg-0.73 at.%Si, Al-1.07 at.%Mg-0.33 at.%Si and Al-1.07 at.%Mg-0.53 at.%Si alloys are presented over a range of constant temperatures between 250 and 320 K. The magnetization vs. time curves for the samples show minima for temperatures near 290 K. The observed times at which the magnetization minima occur were found to depend on both the solute concentrations and the measurement temperatures. From these results the activation energies from the Si-rich clustering stage to the Mg-Si co-clustering stage were extracted. The deduced activation energies were found to be comparable to those from the positron annihilation measurements, depending on the solute concentrations
Laser-Ablated Vortex Fluidic-Mediated Synthesis of Superparamagnetic Magnetite Nanoparticles in Water Under Flow
ACS AuthorChoice - This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposesSelective formation of only one iron oxide phase is a major challenge in conventional laser ablation process, as is scaling up the process. Herein, superparamagnetic single-phase magnetite nanoparticles of hexagonal and spheroidal-shape, with an average size of ca. 15 nm, are generated by laser ablation of bulk iron metal at 1064 nm in a vortex fluidic device (VFD). This is a one-step continuous flow process, in air at ambient pressure, with in situ uptake of the nanoparticles in the dynamic thin film of water in the VFD. The process minimizes the generation of waste by avoiding the need for any chemicals or surfactants and avoids time-consuming purification steps in reducing any negative impact of the processing on the environment.The authors gratefully acknowledge the financial support from the Australia Research Council and the Government of South Australia; also the expertise, equipment, and support provided by the Australian Microscopy and Microanalysis Research Facility (AMMRF) and the Australian National Fabrication Facility (ANFF) at the South Australian nodes of the AMMRF and ANFF under the National Collaborative Research Infrastructure Strategy
When hospitals provide HR practices tailored to older nurses, will older nurses stay? It may depend on their supervisor
This longitudinal study tested a model of the mechanisms through which HR practices are linked to older nurses\u27 intention to remain with their hospital. The participants were 528 registered nurses aged 45 to 67 years. The study focused on two HR practices, flexible work options and performance evaluation practices, which are more directly under the influence of the immediate supervisor. Supervisor-related procedural justice mediated the relationship between the HR practices and perceived supervisor support (PSS), and in turn, PSS was associated with enhanced perceived organisational support (POS). POS partially mediated the relationship between PSS and affective commitment, and affective commitment fully mediated the relationship between POS and older nurses\u27 intention to remain with their hospital. The findings indicated that fostering older nurses\u27 commitment and ultimately retention requires HR practices relevant to older nurses, supportive and fair supervisors, and a hospital that values their contribution and cares about their well-being
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