29,522 research outputs found

    Effectiveness of nurse home-visiting for disadvantaged families: results of a natural experiment

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    Extent: 9p.Objective: To evaluate the effects of a postnatal home-visiting programme delivered by community health nurses to socially disadvantaged mothers in South Australia. Design: The intervention group of 428 mothers lived in metropolitan Adelaide and the comparison group of 239 mothers lived in regional towns where the programme was not yet available. All participating mothers met health service eligibility criteria for enrolment in the home-visiting programme. Participants in both groups were assessed at baseline (mean child age=14.4 weeks SD=2.3), prior to programme enrolment, and again when the children were aged 9, 18 and 24 months. Setting: State-wide community child health service. Participants: 667 socially disadvantaged mothers enrolled consecutively. 487 mothers (73%) completed the 24-month assessment. Intervention: Two-year postnatal home-visiting programme based on the Family Partnership Model. Primary outcome measures: Parent Stress Index (PSI), Kessler Psychological Distress Scale and the Ages and Stages Questionnaire. Results: Mixed models adjusting for baseline differences were used to compare outcomes in the two groups. The mothers in the home-visiting group reported greater improvement on the PSI subscales assessing a mother's perceptions on the quality of their relationship with their child (1.10, 95% CI 0.06 to 2.14) and satisfaction with their role as parents (0.46, 95% CI −0.15 to 1.07) than mothers in the comparison group. With the exception of childhood sleeping problems, there were no other significant differences in the outcomes across the two groups. Conclusions: The findings suggest that home-visiting programmes delivered by community health nurses as part of routine clinical practice have the potential to improve maternal–child relationships and help mothers adjust to their role as parents.Michael Gifford Sawyer, Linda Frost, Kerrie Bowering, John Lync

    (2+1) resonant enhanced multiphoton ionization of H_2 via the E, F^(1)ÎŁ^+_g state

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    In this paper, we report the results of ab initio calculations of photoelectron angular distributions and vibrational branching ratios for the (2+1) REMPI of H_2 via the E, F^(1)Σ^+_g state, and compare these with the experimental data of Anderson et al. [Chem. Phys. Lett. 105, 22 (1984)]. These results show that the observed non‐Franck–Condon behavior is predominantly due to the R dependence of the transition matrix elements, and to a lesser degree to the energy dependence. This work presents the first molecular REMPI study employing a correlated wave function to describe the Rydberg–valence mixing in the resonant intermediate state

    Ethics of tax practice

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    Results of 1/4-Scale Experiments. Vapor Simulant And Liquid Jet A Tests

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    A quarter-scale engineering model of the center wing tank (CWT) of a 747-100 was constructed. This engineering model replicated the compartmentalization, passageways, and venting to the atmosphere. The model was designed to scale the fluid dynamical and combustion aspects of the explosion, not the structural failure of the beams or spars. The effect of structural failure on combustion was examined by using model beams and spars with deliberately engineered weak connections to the main tank structure. The model was filled with a simulant fuel (a mixture of propane and hydrogen) and ignited with a hot wire. The simulant fuel was chosen on the basis of laboratory testing to model the combustion characteristics (pressure rise and flame speed) of Jet A vapor created by a Jet A liquid layer at 50C at an altitude of 13.8 kft. A series of experiments was carried out in this model in order to: (a) investigate combustion in a CWT geometry; and (b) provide guidance to the TWA 800 crash investigation. The results of the experiments were observed with high-speed film, video, and still cameras, fast and slow pressure sensors, thermocouples, photodetectors, and motion sensors. A special pseudo-schlieren system was used to visualize flame propagation within the tank. This report describes the test program, facility, instrumentation, the first 30 experiments, comparisons between experiments, and performance of the instrumentation; then examines the significance of these results to the TWA 800 crash investigation. The key results of this study are: Flame Motion: The motion of flame was dominated by the effects of turbulence created by jetting through the passageways and vent stringers. A very rapid combustion event (lasting 10 to 20 ms) occurred once the flame traveled outside of the ignition bay and interacted with the turbulent flow. Most of the gas within the tank was burned during this rapid event. Compartments: The combustion time decreased with an increasing number of compartments (bays) within the tank. With six bays, combustion took only 100 to 150 ms to be completed from the time of ignition until the end of the rapid combustion phase. The total combustion event was three to four times shorter with compartments than without. Venting: Venting to the outside of the tank through the model vent stringers had a negligible effect on the combustion progress or on the peak pressure reached at the end of the burn. Ignition Location: Variation of the ignition location produced distinctive pressure loads on the structural components. Liquid Fuel: Lofting of a cold liquid fuel layer was produced by the combustion-induced gas motion. Although this spray of liquid eventually ignited and burned, it did not contribute to the pressure loading. Structural Failure: Structural failure resulted in flame acceleration, decreasing the overall combustion time. TWA 800 Investigation: The pressure loads were sufficiently high, up to 4 bar, and the combustion events were sufficiently short, that the forward portion (spanwise beam 3, front spar) of the CWT structure would fail as a direct consequence of the explosion. A combination of pressure loads was produced in some tests consistent with the TWA 800 wreckage. Replica tests, structural modeling, and sensitivity studies on fuel concentration are needed before any conclusions can be drawn about probable ignition locations. Cargo Bay: Tests with a simplified model of a half-full cargo bay indicated that repeated pressure waves with an amplitude of 1 bar or less are produced when an explosion scenario similar to TWA 800 is tested. Future Testing: Future studies should include replica tests, tests with Jet A vapor and warm liquid Jet A layers, and sensitivity tests to examine ignition location, fuel concentration, and vent area perturbations. Summary: Explosion tests in a 747-100 CWT model reveal that a very complex pattern of combustion occurs due the interaction of the flame and the flow-generated turbulence. A wide range of structural load patterns occur, depending on the location of the ignition source. Some of these load patterns are consistent with damage believed to be associated with the initial explosion event in TWA 800. Sensitivity of the loading to the ignition location indicates that narrowing down the ignition location in TWA 800 may be possible. However, the complexity of the combustion and structural failure processes in the actual center wing tank mandates extremely careful consideration of the uncertainties that enter into this process

    Dispersion monitoring for high-speed WDM networks via two-photon absorption in a semiconductor microcavity

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    Due to the continued demand for bandwidth, network operators have to increase the data rates at which individual wavelengths operate at. As these data rates will exceed 100 Gbit/s in the next 5-10 years, it will be crucial to be able to monitor and compensate for the amount of chromatic dispersion encountered by individual wavelength channels. This paper will focus on the use of the novel nonlinear optical-to-electrical conversion process of two-photon absorption (TPA) for dispersion monitoring. By incorporating a specially designed semiconductor microcavity, the TPA response becomes wavelength dependent, thus allowing simultaneous channel selection and monitoring without the need for external wavelength filterin

    Soft-x-ray appearance potential spectra of La and Ce from 0 to 1400 eV

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    The soft-x-ray appearance potential spectra were measured for La and Ce in the 0-1400-eV range. The 3d and 4dspectra exhibited prominent structure, which is discussed along with x-ray absorption and emission data. The excited electron and the core hole interact strongly, and there is evidence for additional interaction with the projectile electron. The two-density-of-states model of Wendin seems promising for explaining the spectra, but it must be extended to allow for the interaction of the projectile electron with the excited atom. The effects of oxidation are described

    Educating the Professional Engineer of 2020: The Changing Licensure Requirements

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    Engineering education programs would be well served to align their curricula and program outcomes to the Fundamentals of Engineering (FE) Exam and Professional Engineer (PE) Exam specifications. These exams are required steps in the process of becoming a licensed engineer in most states. NCEES (the National Council of Examiners for Engineering and Surveying) is a national nonprofit organization dedicated to advancing professional licensure for engineers and surveyors. It develops, administers, and scores these examinations used for engineering licensure. Starting in 2011, NCEES held survey-creation meetings with diverse teams to develop a draft survey containing the subjects in each discipline and establish consensus support. NCEES launched a web-based survey of technical society members, institution report recipients, deans and department heads of all EAC/ABET programs, PE and FE exam committee volunteers, and others; more than 7,000 people completed the survey. Respondents rated the importance of each topic area to indicate how important it is for a new engineer to have minimum competence in that area. Based on these survey results, a set of topics and associated weighting was proposed and approved. Starting in 2014 the various FE exams will contain some overlapping content (e.g., mathematics and engineering economics), but there will no longer be a common breadth portion. Each FE exam, including industrial engineering, will be a freestanding exam. The PE exam specifications have also been revised; the new specifications will be used beginning in 2013. This paper highlights these recent changes to the discipline-specific content of the industrial engineering (IE) exams and suggests possible resulting curriculum modifications. As the IE profession undergoes changes in its application of traditional principles and adds new areas of focus, it is timely that the FE and PE exam specifications have been revisited to reflect changing priorities within the profession. For academic departments to stay relevant and assist industrial engineering graduates to become PE licensed, modern curriculum should stay closely aligned to the FE and PE exam specifications but not attempt to teach to the test . The paper concludes with a discussion of how these specifications have been used to assess and update academic curriculum
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