Spheroidisation of metal powder by pulsed electron beam irradiation

A new powder spheroidisation process has been demonstrated using a large-area, pulsed electron beam technique. This was used to dramatically improve the surface morphology of Stellite 6 metal powder. Powder surface asperities up to 20 μm size can be eliminated by melting and incorporation into the near-surface of the particle. Surface finish is significantly improved. Agitation and rotation of particles due to a beam-induced stress wave enables the irradiation of multiples sides of particles, resulting in uniformly smoothed particles after sufficient pulses. Elemental analysis revealed no measurable contamination as a result of the process. Transmission electron microscopy showed a dense layer is produced within a zone up to 3 μm beneath the surface, with a substantially reduced grain size from ca. 2 μm diameter in the bulk to ca. 40 nm. Elemental homogenisation also was accompanied by grain refinement. The irradiated Stellite 6 showed a reduced basic flowability energy (583 mJ compared to 627 mJ for the untreated), explained by reduced particle-particle cohesion and interlocking, and an increased conditioned bulk density of 4.57 g/ml compared to 4.33 g/ml due to satellite/asperity reduction

Dominant g(9/2)^2 neutron configuration in the 4+1 state of 68Zn based on new g factor measurements

The $g$ factor of the $4_1^+$ state in $^{68}$Zn has been remeasured with improved energy resolution of the detectors used. The value obtained is consistent with the previous result of a negative $g$ factor thus confirming the dominant $0g_{9/2}$ neutron nature of the $4_1^+$ state. In addition, the accuracy of the $g$ factors of the $2_1^+$, $2_2^+$ and $3_1^-$ states has been improved an d their lifetimes were well reproduced. New large-scale shell model calculations based on a $^{56}$Ni core and an $0f_{5/2}1pg_{9/2}$ model space yield a theoretical value, $g(4_1^+) = +0.008$. Although the calculated value is small, it cannot fully explain the experimental value, $g(4_1^+) = -0.37(17)$. The magnitude of the deduced B(E2) of the $4_1^+$ and $2_1^+$ transition is, however, rather well described. These results demonstrate again the importance of $g$ factor measurements for nuclear structure determination s due to their specific sensitivity to detailed proton and neutron components in the nuclear wave functions.Comment: 7 pages, 3 figs, submitted to PL

You\u27re Going to Lose Your Honey Boy

Illustration of school girlhttps://scholarsjunction.msstate.edu/cht-sheet-music/1320/thumbnail.jp

CAPS-1 and CAPS-2 are essential synaptic vesicle priming proteins

SummaryBefore transmitter-filled synaptic vesicles can fuse with the plasma membrane upon stimulation they have to be primed to fusion competence. The regulation of this priming process controls the strength and plasticity of synaptic transmission between neurons, which in turn determines many complex brain functions. We show that CAPS-1 and CAPS-2 are essential components of the synaptic vesicle priming machinery. CAPS-deficient neurons contain no or very few fusion competent synaptic vesicles, which causes a selective impairment of fast phasic transmitter release. Increases in the intracellular Ca2+ levels can transiently revert this defect. Our findings demonstrate that CAPS proteins generate and maintain a highly fusion competent synaptic vesicle pool that supports phasic Ca2+ triggered release of transmitters

Transitory electrochemical masking for precision jet processing techniques

Electrochemical jet processing techniques provide an efficient method for large area surface structuring and micro-milling, where the metallurgy of the near-surface is assured and not adversely affected by thermal loading. Here, doped electrolytes are specifically developed for jet techniques to exploit the Gaussian energy distribution as found in energy beam processes. This allows up to 26% reduction in dissolution kerf and enhancements of the defined precision metric of up to 284% when compared to standard electrolytes. This is achieved through the filtering of low energy at discrete points within the energy distribution curve. Two fundamental mechanisms of current filtering and refresh rate are proposed and investigated in order to underpin the performance enhancements found using this methodology. This study aims to demonstrate that a step change in process fidelity and flexibility can be achieved through optimisation of the electrochemistry specific to jet processes

Consensus and contention in the priority setting process: examining the health sector in Uganda.

Health priority setting is a critical and contentious issue in low-income countries because of the high burden of disease relative to the limited resource envelope. Many sophisticated quantitative tools and policy frameworks have been developed to promote transparent priority setting processes and allocative efficiency. However, low-income countries frequently lack effective governance systems or implementation capacity, so high-level priorities are not determined through evidence-based decision-making processes. This study uses qualitative research methods to explore how key actors' priorities differ in low-income countries, using Uganda as a case study. Human resources for health, disease prevention and family planning emerge as the common priorities among actors in the health sector (although the last of these is particularly emphasized by international agencies) because of their contribution to the long-term sustainability of health-care provision. Financing health-care services is the most disputed issue. Participants from the Ugandan Ministry of Health preferentially sought to increase net health expenditure and government ownership of the health sector, while non-state actors prioritized improving the efficiency of resource use. Ultimately it is apparent that the power to influence national health outcomes lies with only a handful of decision-makers within key institutions in the health sector, such as the Ministries of Health, the largest bilateral donors and the multilateral development agencies. These power relations reinforce the need for ongoing research into the paradigms and strategic interests of these actors