A technique for making clean holes in metallic piping and components

Testing was conducted to develop a technique of providing clean holes in process piping or in a metal surface accessible from one side only without disassembling the system. The method was performed on sample pieces of piping and worked successfully with no contaminants being found on the inside of the pipe. The materials tested were Inconel 600, 304 stainless steel, Hastelloy X, and ASTM-A53 black steel. The technique was developed such that it could be done in the field with hand-held power tools and a portable tungsten inert gas welding machine

Coherent optical transfer of Feshbach molecules to a lower vibrational state

Using the technique of stimulated Raman adiabatic passage (STIRAP) we have coherently transferred ultracold 87Rb2 Feshbach molecules into a more deeply bound vibrational quantum level. Our measurements indicate a high transfer efficiency of up to 87%. As the molecules are held in an optical lattice with not more than a single molecule per lattice site, inelastic collisions between the molecules are suppressed and we observe long molecular lifetimes of about 1 s. Using STIRAP we have created quantum superpositions of the two molecular states and tested their coherence interferometrically. These results represent an important step towards Bose-Einstein condensation (BEC) of molecules in the vibrational ground state.Comment: 4 pages, 5 figure

Cruising through molecular bound state manifolds with radio frequency

The emerging field of ultracold molecules with their rich internal structure is currently attracting a lot of interest. Various methods have been developed to produce ultracold molecules in pre-set quantum states. For future experiments it will be important to efficiently transfer these molecules from their initial quantum state to other quantum states of interest. Optical Raman schemes are excellent tools for transfer, but can be involved in terms of equipment, laser stabilization and finding the right transitions. Here we demonstrate a very general and simple way for transfer of molecules from one quantum state to a neighboring quantum state with better than 99% efficiency. The scheme is based on Zeeman tuning the molecular state to avoided level crossings where radio-frequency transitions can then be carried out. By repeating this process at different crossings, molecules can be successively transported through a large manifold of quantum states. As an important spin-off of our experiments, we demonstrate a high-precision spectroscopy method for investigating level crossings.Comment: 5 pages, 5 figures, submitted for publicatio

Performance and evaluation of two liquid-metal pumps for sodium-potassium service

Performance tests on liquid metal pumps for sodium potassium loop

The psychological contract of knowledge workers

Purpose: This paper explores whether the concept of psychological contracts underpinned by relational/transactional exchanges provides an adequate description of knowledge workers’ contracts. Methodology: The research approach uses interviews with 10 scientists from within a pre-eminent Australian scientific research and development organisation, the Commonwealth Scientific & Industrial Research Organisation (CSIRO). Findings: The research strong evidence of an ideological currency within the psychological contract for this set of knowledge workers. Implications: The research raises questions over the role of normative occupation-specific beliefs about work, and the sharing of common currency elements by individuals in the same organization within the same occupation. The analysis lends support to calls in the literature for a reconsideration of the transactional/relational interpretative framework that underpins the psychological contract

A hidden dimension? Work ideology and psychological contracts.

This paper explores whether the concept of psychological contracts underpinned by relational/transactional exchanges provides an adequate description of knowledge workers’ contracts. Interviews were conducted with scientists from the CSIRO. The analysis identified content of the psychological contract for the knowledge worker best understood by reference to an ideological currency. It raises questions over the role of normative occupation-specific beliefs about work, and the sharing of common currency elements by individuals in the same organization within the same occupation. The analysis lends support to calls in the literature for a reconsideration of the transactional/relational interpretative framework that underpins the psychological contract

Atomistic studies of transformation pathways and energetics in plutonium

One of the most challenging problems in understanding the structural phase transformations in Pu is to determine the energetically favored, continuous atomic pathways from one crystal symmetry to another. This problem involves enumerating candidate pathways and studying their energetics to garner insight into instabilities and energy barriers. The purpose of this work is to investigate the energetics of two transformation pathways for the delta to alpha' transformation in Pu that were recently proposed [Lookman et al., Phys. Rev. Lett. 100:145504, 2008] on the basis of symmetry. These pathways require the presence of either an intermediate hexagonal closed-packed (hcp) structure or a simple hexagonal (sh) structure. A subgroup of the parent fcc and the intermediate hexagonal structure, which has trigonal symmetry, facilitates the transformation to the intermediate hcp or sh structure. Phonons then break the translational symmetry from the intermediate hcp or sh structure to the final monoclinic symmetry of the alpha' structure. We perform simulations using the modified embedded atom method (MEAM) for Pu to investigate these candidate pathways. Our main conclusion is that the path via hcp is energetically favored and the volume change for both pathways essentially occurs in the second step of the transformation, i.e. from the intermediate sh or hcp to the monoclinic structure. Our work also highlights the deficiency of the current state-of-the-art MEAM potential in capturing the anisotropy associated with the lower symmetry monoclinic structure.Comment: 12 pages, 5 figures, accepted for publication in Philos. Ma