2,275 research outputs found

    Spitzer/MIPS Imaging of NGC 650: Probing the History of Mass Loss on the Asymptotic Giant Branch

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    We present the far-infrared (IR) maps of a bipolar planetary nebula (PN), NGC 650, at 24, 70, and 160 micron taken with the Multiband Imaging Photometer for Spitzer (MIPS) on-board the Spitzer Space Telescope. While the two-peak emission structure seen in all MIPS bands suggests the presence of a near edge-on dusty torus, the distinct emission structure between the 24 micron map and the 70/160 micron maps indicates the presence of two distinct emission components in the central torus. Based on the spatial correlation of these two far-IR emission components with respect to various optical line emission, we conclude that the 24 micron emission is largely due to the [O IV] line at 25.9 micron arising from highly ionized regions behind the ionization front, whereas the 70 and 160 micron emission is due to dust continuum arising from low-temperature dust in the remnant asymptotic giant branch (AGB) wind shell. The far-IR nebula structure also suggests that the enhancement of mass loss at the end of the AGB phase has occurred isotropically, but has ensued only in the equatorial directions while ceasing in the polar directions. The present data also show evidence for the prolate spheroidal distribution of matter in this bipolar PN. The AGB mass loss history reconstructed in this PN is thus consistent with what has been previously proposed based on the past optical and mid-IR imaging surveys of the post-AGB shells.Comment: 9 pages in the emulated ApJ format with 6 figures, to appear in Ap

    Barriers to career advancement for female engineers in Australia’s civil construction industry and recommended solutions

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    © 2019, © 2019 Engineers Australia. This study explores the challenges that have emerged from the outdated and inflexible workplace culture of the civil construction industry, and how it is affecting female engineers and women in other functional site roles. The study primarily explores issues such as the strong culture of long work hours, the perception of staff who pursue work-life balance, and the perception of part time and flexible working options within the industry. The study was conducted over three phases where members of the industry answered questionnaires on the workplace issues listed above. The first phase aimed to document a female perspective on the construction workplace culture while the second phase focused on the perceptions of the same respondents regarding the industry’s attitude to work-life balance and whether any of the aspects of workplace culture has discouraged them from staying in the industry. The final phase included men and women in management and employer roles to determine their views on part time and flexible working options within the industry. The results of the study are presented and discussed before recommendations are offered for contractor organisations, their employers and staff. The recommendations have been addressed in a way that a gradual culture change can be accepted and acted on throughout the entire workplace

    DIFFERENCES IN TEMPORAL VARIABLES AND THEIR EFFECT ON KINETICS IN HIGH SCHOOL PITCHERS WITH HIGH AND LOW PITCH VELOCITIES

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    The purpose of this study was to compare temporal parameters between high and low velocity high school (HS) pitchers and investigate the influence these parameters have on both pitch speed and upper extremity kinetics. 30 healthy right-handed HS male pitchers with no recent injuries, and clearance to play were included. A 3D motion analysis system was used. Analysis included 15 kinetic and 35 temporal variables. Statistical tests conducted in SPSS. Correlation strength was interpreted as weak, moderate, or strong. High velocity and low velocity throwers showed differences in the timing to progress through the pitching cycle and these temporal variables showed separate relations to pitch speed and kinetics

    Response to comment on "solid recovered fuel: Materials flow analysis and fuel property development during the mechanical processing of biodried waste"

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    Laner and Cencic1 comment on Velis et al. (2013)2 clarifying certain points on the use of the material flow analysis (MFA) software STAN3. We welcome the correspondence and the opportunity this exchange provides to discuss optimal approaches to using STAN. In keeping with Velis et al.2 these physically impossible, and otherwise insignificant, negative flows have enabled improvements to STAN. Here, we elaborate on the practicalities of using STAN in our research and on the correctness and validation of our results, notwithstanding the inclusion of negative flows. We explain the contribution of our approach to solid waste management and resource recovery

    Generation of a short fibre biocomposite representative volume element

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    One of the greatest challenge in working with natural fibre composites is the large variation in mechanical properties that result from the geometric inconsistency amongst fibres. Traditional design tools and models are unable to accurately incorporate this non-homogeneity to predict the resulting local behaviour of biocomposite materials. The following paper presents a methodology to generate a representative volume element (RVE) to simulate the material microstructure of short fibre composites, with the intent of modelling the popular class of short fibre biocomposites materials. The capabilities of a range of particle packing algorithms used in literature are compared in terms of the maximum volume fraction they have been able to achieve and for what fibre length to diameter aspect ratio. The methodology is able to account for the characteristics of fibre geometry samples, according to their probability density functions (PDFs). The RVE generation strategy imposes periodic boundary conditions and fibres are declared invalid if an intersection between fibres is detected. The effect of different PDFs on the resulting RVE are discussed. An RVE populated with data following a Weibull distribution is compared to that from normally distributed data with an equal mean but varied standard deviations. Using a Weibull distribution to simulate the characteristics of an RVE requires a significantly higher number of fibres than any comparable normal distribution, due to the skewness of the data towards large values at low probabilities. The highest volume fraction achieved was 40% for an RVE containing fibres with lengths distributed according to a Weibull distribution and aspect ratios of 15. The future intent of this work is to perform finite element analysis on RVE samples with a range of varied microstructure characteristics to determine the effect on overall composite properties, which will provide new insights on how best to formulate short fibre compounds

    An Interim Analysis of an Advance Care Planning Intervention in the Nursing Home Setting

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    Objectives To describe processes and preliminary outcomes from the implementation of a systematic advance care planning (ACP) intervention in the nursing home setting. Design Specially trained project nurses were embedded in 19 nursing homes and engaged in ACP as part of larger demonstration project to reduce potentially avoidable hospitalizations. Setting Nursing homes. Participants Residents enrolled in the demonstration project for a minimum of 30 days between August 2013 and December 2014 (n = 2,709) and residents currently enrolled in March 2015 (n = 1,591). Measurements ACP conversations were conducted with residents, families, and the legal representatives of incapacitated residents using a structured ACP interview guide with the goal of offering ACP to all residents. Project nurses reviewed their roster of currently enrolled residents in March 2015 to capture barriers to engaging in ACP. Results During the initial implementation phase, 27% (731/2,709) of residents had participated in one or more ACP conversations with a project nurse, resulting in a change in documented treatment preferences for 69% (504/731). The most common change (87%) was the generation of a Physician Orders for Scope of Treatment form. The most frequently reported barrier to ACP was lack of time. Conclusion The time- and resource-intensive nature of robust ACP must be anticipated when systematically implementing ACP in the nursing home setting. The fact that these conversations resulted in changes over 2/3 of the time reinforces the importance of deliberate, systematic ACP to ensure that current treatment preferences are known and documented so that these preferences can be honored
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