7,194 research outputs found

    Development of superconductive magnets

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    Survey of superconductive magnets considers - stabilization problems, advances in materials and their uses, and design evolution. Uses of superconducting magnets in particle accelerators and bubble chambers, as well as possible applications in magnetohydrodynamic and thermonuclear power generation and levitation are discussed

    Apparatus and method for explosive bonding to edge of flyer plate

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    The invention is an apparatus and a process for the explosive joining of a flyer plate and a base plate. The apparatus consists of a flyer plate positioned over a base plate. The flyer plate has a notch containing a filler material in intimate contact with the flyer plate. An adhesive means holds a ribbon explosive partially overlapping the notch in the flyer plate. A detonating means initiates the ribbon explosive that drives the flyer plate to accomplish a high velocity, angular collision between the mating surfaces. This collision creates surface melts and effacing bonding, resulting in electron sharing linkups between the plates. An unbonded tab fractures at a base of the notch leaving a bond to an edge of the attached flyer plate

    Permanent wire splicing by an explosive joining process

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    The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebent, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires, and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding results in electron sharing linkups

    New twisted intermetallic compound superconductor: A concept

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    Method for processing Nb3Sn and other intermetallic compound superconductors produces a twisted, stabilized wire or tube which can be used to wind electromagnetics, armatures, rotors, and field windings for motors and generators as well as other magnetic devices

    Method of fabricating a twisted composite superconductor

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    A method of producing a twisted, stabilized wire or tube superconductor which can be used to wind electromagnets, armatures, rotors, field windings for motors and generators, and other magnetic devices which use a solenoid, toroidal, or other type winding is reported. At least one groove is formed along the length of a wire substrate which is then twisted into a helix and a layer of intermetallic superconducting material is formed in the groove. This layer can be formed by depositing the desired intermetallic compound into the groove or by diffusing one component of the superconductor into the groove formed in a substrate composed of the other component. The superconductor prepared by this method comprises a non-superconductor wire twisted into the shape of a helix, having at least one groove containing a layer of superconductor material along the length of the wire

    What will make a difference? Assessing the impact of policy and non-policy scenarios on estimations of the future GP workforce

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    Published online: 28 June 2017Background: Health workforce planning is based on estimates of future needs for and supply of health care services. Given the pipeline time lag for the training of health professionals, inappropriate workforce planning or policies can lead to extended periods of over- or under-supply of health care providers. Often these policy interventions focus on one determinant of supply and do not incorporate other determinants such as changes in population health which impact the need for services. The aim of this study is to examine the effect of the implementation of various workforce policies on the estimated future requirements of the GP workforce, using South Australia as a case study. This is examined in terms of the impact on the workforce gap (excess or shortage), the cost of these workforce policies, and their role in addressing potential non-policy-related future scenarios. Methods: An integrated simulation model for the general practice workforce in South Australia was developed, which determines the supply and level of services required based on the health of the population over a projection period 2013–2033. The published model is used to assess the effects of various policy and workforce scenarios. For each policy scenario, associated costs were estimated and compared to baseline costs with a 5% discount rate applied. Results: The baseline scenario estimated an excess supply of GPs of 236 full-time equivalent (FTE) in 2013 but this surplus decreased to 28 FTE by 2033. The estimates based on single policy scenarios of role substitution and increased training positions continue the surplus, while a scenario that reduces the number of international medical graduates (IMGs) recruited estimated a move from surplus to shortage by 2033. The best-case outcome where the workforce achieves balance by 2023 and remains balanced to 2033, arose when GP participation rates (a non-policy scenario) were combined with the policy levers of increased GP training positions and reduced IMG recruitment. The cost of each policy varied, with increased role substitution and reduced IMG recruitment resulting in savings (AUD752,946,586andAUD752,946,586 and AUD3,783,291 respectively) when compared to baseline costs. Increasing GP training costs over the projection period would cost the government an additional AUD$12,719,798. Conclusions: Over the next 20 years, South Australia’s GP workforce is predicted to remain fairly balanced. However, exogenous changes, such as increased demand for GP services may require policy intervention to address associated workforce shortfalls. The workforce model presented in this paper should be updated at regular intervals to inform the need for policy intervention.Caroline O. M. Laurence and Jonathan Karno

    Bloodstream form trypanosoma brucei depend upon multiple metacaspases associated with RAB11-positive endosomes

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    Trypanosoma brucei possesses five metacaspase genes. Of these, MCA2 and MCA3 are expressed only in the mammalian bloodstream form of the parasite, whereas MCA5 is expressed also in the insect procyclic form. Triple RNAi analysis showed MCA2, MCA3 and MCA5 to be essential in the bloodstream form, with parasites accumulating pre-cytokinesis. Nevertheless, triple null mutants (Δmca2/3Δmca5) could be isolated after sequential gene deletion. Thereafter, Δmca2/3Δmca5 mutants were found to grow well both in vitro in culture and in vivo in mice. We hypothesise that metacaspases are essential for bloodstream form parasites, but they have overlapping functions and their progressive loss can be compensated for by activation of alternative biochemical pathways. Analysis of Δmca2/3Δmca5 revealed no greater or lesser susceptibility to stresses reported to initiate programmed cell death, such as treatment with prostaglandin D2. The metacaspases were found to colocalise with RAB11, a marker for recycling endosomes. However, variant surface glycoprotein (VSG) recycling processes and the degradation of internalised anti-VSG antibody were found to occur similarly in wild type, Δmca2/3Δmca5 and triple RNAi induced parasites. Thus, the data provide no support for the direct involvement of T. brucei metacaspases in programmed cell death and suggest that the proteins have a function associated with RAB11 vesicles that is independent of known recycling processes of RAB11-positive endosomes

    The Ha Luminosity Function and Star Formation Rate at z\sim 0.2

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    We have measured the Ha+[N II] fluxes of the I-selected Canada-France Redshift Survey (CFRS) galaxies lying at a redshift z below 0.3, and hence derived the Ha luminosity function. The magnitude limits of the CFRS mean that only the galaxies with M(B) > -21 mag were observed at these redshifts. We obtained a total Ha luminosity density of at least 10^{39.44\pm 0.04} erg/s/Mpc^{3} at a mean z=0.2 for galaxies with rest-fame EW(Ha+[N II]) > 10 Angs. This is twice the value found in the local universe by Gallego et al. 1995. Our Ha star formation rate, derived from Madau (1997) is higher than the UV observations at same z, implying a UV dust extinction of about 1 mag. We found a strong correlation between the Ha luminosity and the absolute magnitude in the B-band: M(B(AB)) = 46.7 - 1.6 log L(Ha). This work will serve as a basis of future studies of Ha luminosity distributions measured from optically-selected spectroscopic surveys of the distant universe, and it will provide a better understanding of the physical processes responsible for the observed galaxy evolution.Comment: Accepted for publication in ApJ, 14 pages, LaTeX (macro aas2pp4.sty), 6 figure

    State Primary Stroke Center Policies in the US: Rural Health Issues.

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    Objective: To explore the relationship between state primary stroke center (PSC) designation policy implementation and access to optimal stroke care for residents of rural areas. Materials and Methods: Primary data were collected during the period September 2008–August 2009. Following content analysis of state PSC policies, four case study states were selected for fieldwork, in part for state rural healthcare access challenges. Variables included the barriers and facilitators to PSC designation policy implementation. More than 100 semistructured stakeholder interviews were conducted by teams of researchers. Large-group meetings were also observed. Interview summaries were reviewed by stakeholders for accuracy and completeness. Results: The consistent finding in all study states was that PSC designation and state policy implementation in rural areas are unlikely for a variety of reasons, including lack of financial resources for telemedicine, difficulty maintaining neurology coverage, and emergency departments unable to administer thrombolytics. Findings indicate recognition by states about the need for stroke-care public policy specific to telemedicine in rural areas. Conclusions: Although state PSC designation policies raise awareness of rural issues, designation policy alone cannot overcome the obstacle of rural access to optimal stroke care. States must be technology-ready, and providers need to embrace e-health and telemedicine to ensure coordination of care for stroke victims in rural areas. More important is that state policy makers should provide rules and regulations to encourage PSC hospitals to use telemedicine and “proxy credentialing” to support their affiliated rural facilitie
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