Thermal and convection analyses of the dendrite remelting rocket experiment; Experiment 74-21 in the space processing rocket program

The Dendrite Remelting Rocket Experiment was performed aboard a Black Brant VC Sounding Rocket during a period which gravity levels of approximately 0.00001 g prevailed. The experiment consisted of cooling an aqueous ammonium chloride solution in a manner such that crystallization of ammonium chloride crystals proceeded throughout a three minute period of zero-g. The crystallization process during flight was recorded on 35 mm panatomic-x film. A number of ground crystallizations were similarly recorded for comparison purposes. The convective and thermal conditions in aqueous and metallic liquid systems were assessed under conditions of the flight experiment to help establish the relevance of the rocket experiment to metals casting phenomena. The results indicate that aqueous or metallic convective velocities in the Dendrite Remelting Rocket Experiment cell are of insignificant magnitudes at the 0.0001 to 0.00001 g levels of the experiment. The crystallization phenomena observed in the Rocket Experiment, therefore, may be indicative of how metals will solidify in low-g

The Sommerfeld half-plane problem revisited, IV: Variations on a theme of Carlson and Heins

A plane wave is incident upon an infinite set of equally spaced, semi-infinite parallel and staggered plates. The boundary conditions on the plates alternate between the Dirichlet and Neumann ones. This problem is formulated as a pair of coupled Wiener-Hopf integral equations and solved by a method proposed by A. E. Heins in 1950. For the case of specular reflection, that is, a single reflected plane wave, the magnitudes of the reflection coefficient and the transmission coefficients are determined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50172/1/1670100307_ftp.pd

Analytical support for SPAR experiment 76-36

The apparatus, materials, and procedures used in an analysis of thermal, convective, and rotational fluid flow for a second series of rocket experiments of dendrite growth are described. A constitutive supercooling criterion was calculated from the thermal data. A convection analysis was made of the various cases to ensure that convective velocities will not exceed about .01 cm/sec in the low-g tests. Damping times for fluid flow generated by rocket spin-up and spin-down were also determined, so that the conditions for this experiment are generally the same as those for the SPAR experiment 74-21 study of ammonium chloride low-g crystallizations

Allocation of Communications to Reduce Mental Workload

As the United States Department of Defense continues to increase the number of Remotely Piloted Aircraft (RPA) operations overseas, improved Human Systems Integration becomes increasingly important. Manpower limitations have motivated the investigation of Multiple Aircraft Control (MAC) configurations where a single pilot controls multiple RPAs simultaneously. Previous research has indicated that frequent, unpredictable, and oftentimes overwhelming, volumes of communication events can produce unmanageable levels of system induced workload for MAC pilots. Existing human computer interface design includes both visual information with typed responses, which conflict with numerous other visual tasks the pilot performs, and auditory information that is provided through multiple audio devices with speech response. This paper extends previous discrete event workload models of pilot activities flying multiple aircraft. Specifically, we examine statically reallocating communication modality with the goal to reduce and minimize the overall pilot cognitive workload. The analysis investigates the impact of various communication reallocations on predicted pilot workload, measured by the percent of time workload is over a saturation threshold

Causes and Consequences of Broad-Scale Changes in the Distribution of Migratory Caribou (Rangifer tarandus) of Southern Hudson Bay

Understanding the factors driving changes in species distributions is fundamental to conservation, but for wide-ranging species this is often complicated by the need for broad-scale observations across space and time. In the last three decades, the location of summer concentrations of migratory caribou (Rangifer tarandus) in southern Hudson Bay (SHB), Canada, has shifted south and east as much as 500 km. We used long-term data (1987 – 2011) to test two hypotheses that could explain the distribution shift: forage depletion and anthropogenic disturbance. Over time and space, we compared the body size of live-captured adult female caribou, dietary quality from fecal nitrogen in July, the location of VHF- and GPS-collared female caribou in July, distribution of all-terrain vehicle (ATV) tracks and caribou tracks in August, and the proximity of collared caribou to sections of the coast with higher ATV activity in spring and summer. The forage depletion hypothesis was supported by greater body size and dietary quality in caribou of the eastern portion of SHB than in western SHB animals in 2009 – 11. The anthropogenic disturbance hypothesis was supported by the negative correlation of the distributions of ATV tracks and caribou tracks on the coast in 2010 and the fact that caribou avoided areas with ATV activity by 10 – 14 km. In 1987, collared caribou were observed largely along the coast in western SHB in mid-July, while in 2009 – 11, they were inland in western SHB and along the coast in eastern SHB. While these locations demonstrate a substantial change in summer distri­bution over three decades, we were unable to differentiate between forage depletion and anthropogenic disturbance as a single causal factor of the distribution shift.La compréhension des facteurs qui influencent les changements caractérisant les distributions des espèces est fondamentale aux efforts de conservation, mais pour les espèces dont l’aire de distribution est étendue, ce principe est souvent compliqué par la nécessité de faire des observations à grande échelle, dans le temps et dans l’espace. Au cours des trois dernières décennies, l’emplacement des concentrations estivales du caribou migrateur (Rangifer tarandus) dans le sud de la baie d’Hudson (SBH), au Canada, s’est déplacé vers le sud et vers l’est dans une mesure de 500 km. Nous nous sommes appuyés sur des données de longue haleine (1987–2011) pour mettre à l’épreuve deux hypothèses susceptibles d’expliquer ce changement en matière de distribution, soit l’appauvrissement du fourrage et la perturbation anthropique. Au fil du temps et de l’espace, nous avons comparé la taille du corps des caribous femelles adultes capturées vivantes, la qualité de leur alimentation à partir de l’azote fécal en juillet, l’emplacement des femelles portant un collier de type VHF ou GPS en juillet, la répartition des traces de véhicules tout terrain (VTT) et des pistes de caribou en août de même que la proximité des caribous portant un collier aux tronçons de la côte où la présence de VTT est plus grande au printemps et à l’été. L’hypothèse de l’appauvrissement du fourrage a été étayée par la plus grande taille du corps et la qualité de l’alimentation du caribou de la zone est du SBH comparativement à celles du caribou de l’ouest du SBH entre 2009 et 2011. Pour sa part, l’hypothèse perturbation anthropique a été appuyée par la corrélation négative caractérisant la répartition des pistes de VTT et des traces de caribou sur la côte en 2010 et par le fait que les caribous sont restés à l’écart des zones fréquentées par les VTT dans une mesure de 10 à 14 km. En 1987, des caribous portant un collier ont été observés en grand nombre le long de la côte ouest du SBH à la mi-juillet, tandis que de 2009 à 2011, ils ont été repérés à l’intérieur des terres dans l’ouest du SBH et le long de la côte est du SBH. Bien que ces emplacements indiquent un important changement en matière de distribution estivale au cours de trois décennies, nous n’avons pas été en mesure de faire une distinction entre l’appauvrissement du fourrage et la perturbation anthropique en tant que facteur causal unique du changement de distribution

Plasticity in dormancy behaviour of Calanoides acutus in Antarctic coastal waters

Copepods that enter dormancy, such as Calanoides acutus, are key primary consumers in Southern Ocean food webs where they convert a portion of the seasonal phytoplankton biomass into a longer-term energetic and physiological resource as wax ester (WE) reserves. We studied the seasonal abundance and lipid profiles of pre-adult and adult C. acutus in relation to phytoplankton dynamics on the Western Antarctic Peninsula. Initiation of dormancy occurred when WE unsaturation was relatively high, and chlorophyll a (Chl a) concentrations, predominantly attributable to diatoms, were reducing. Declines in WE unsaturation during the winter may act as a dormancy timing mechanism with increased Chl a concentrations likely to promote sedimentation that results in a teleconnection between the surface and deep water inducing ascent. A late summer diatom bloom was linked to early dormancy termination of females and a second spawning event. The frequency and duration of high biomass phytoplankton blooms may have consequences for the lifespan of the iteroparous C. acutus females (either 1 or 2 years) if limited by a total of two main spawning events. Late summer recruits, generated by a second spawning event, likely benefitted from lower predation and high phytoplankton food availability. The flexibility of copepods to modulate their life-cycle strategy in response to bottom-up and top-down conditions enables individuals to optimize their probability of reproductive success in the very variable environment prevalent in the Southern Ocean

Australian long-term care personnel's knowledge and attitudes regarding palliative care for people with advanced dementia.

This study aimed to describe Australian long-term care (LTC) personnel's knowledge and attitudes concerning palliative care for residents with advanced dementia, and explore relationships with LTC facility/personnel characteristics. An analysis was undertaken of baseline data from a cluster randomised controlled trial of facilitated family case conferencing for improving palliative care of LTC residents with advanced dementia (the 'IDEAL Study'). Participants included any LTC personnel directly involved in residents' care. Knowledge and attitudes concerning palliative care for people with advanced dementia were measured using the questionnaire on Palliative Care for Advanced Dementia. Univariate and multivariate analyses explored relationships between personnel knowledge/attitudes and facility/personnel characteristics. Of 307 personnel in the IDEAL Study, 290 (94.5%) from 19/20 LTCFs provided sufficient data for inclusion. Participants included 9 (2.8%) nurse managers, 59 (20.5%) registered nurses, 25 (8.7%) enrolled nurses, 187 (64.9%) assistants in nursing/personal care assistants and 9 (3.1%) care service employees. In multivariate analyses, a facility policy not to rotate personnel through dementia units was the only variable associated with more favourable overall personnel knowledge and attitudes. Other variables associated with favourable knowledge were a designation of nursing manager or registered or enrolled nurse, and having a preferred language of English. Other variables associated with favourable attitudes were tertiary level of education and greater experience in dementia care. Like previous international research, this study found Australian LTC personnel knowledge and attitudes regarding palliative care for people with advanced dementia to be associated with both facility and personnel characteristics. Future longitudinal research is needed to better understand the relationships between knowledge and attitudes, as well as between these attributes and quality of care

Mechanical Testing of 3D Printed Prosthetics

The Rapid Orthotics for CURE Kenya team as a whole aims to empower the orthopedic technicians in the CURE Kenya hospital by creating, optimizing, and testing 3D printed prosthetics and orthotics. Our team started in 2016 by creating a 3D printing process for below the knee prosthetic sockets. Since then, we had adapted to the hospital\u27s needs over the years, expanding the capabilities of the system itself. Presently, a section of our team has worked specifically with these leg sockets to ensure the safety and functionality for patients. They have done testing to make sure the sockets are strong enough and to make sure the silicone liners are safe for use in developing countries. In addition to safety testing, over the years we have created ankle-foot orthotics and prosthetic hands. The design part of our team works to create new 3D printed devices to help our clients reach more patients. By 2024 we hope to fully integrate our expanded system in the orthopedic workshop in Kijabe, Kenya.https://mosaic.messiah.edu/engr2020/1018/thumbnail.jp

Effects of facilitated family case conferencing for advanced dementia: A cluster randomised clinical trial

© 2017 Agar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background: Palliative care planning for nursing home residents with advanced dementia is often suboptimal. This study compared effects of facilitated case conferencing (FCC) with usual care (UC) on end-of-life care. Methods: A two arm parallel cluster randomised controlled trial was conducted. The sample included people with advanced dementia from 20 Australian nursing homes and their families and professional caregivers. In each intervention nursing home (n = 10), Palliative Care Planning Coordinators (PCPCs) facilitated family case conferences and trained staff in person-centred palliative care for 16 hours per week over 18 months. The primary outcome was family-rated quality of end-of-life care (End-of-Life Dementia [EOLD] Scales). Secondary outcomes included nurse-rated EOLD scales, resident quality of life (Quality of Life in Late-stage Dementia [QUALID]) and quality of care over the last month of life (pharmacological/ non-pharmacological palliative strategies, hospitalization or inappropriate interventions). Results: Two-hundred-eighty-six people with advanced dementia took part but only 131 died (64 in UC and 67 in FCC which was fewer than anticipated), rendering the primary analysis underpowered with no group effect seen in EOLD scales. Significant differences in pharmacological (P < 0.01) and non-pharmacological (P < 0.05) palliative management in last month of life were seen. Intercurrent illness was associated with lower family-rated EOLD Satisfaction with Care (coefficient 2.97, P < 0.05) and lower staff-rated EOLD Comfort Assessment with Dying (coefficient 4.37, P < 0.01). Per protocol analyses showed positive relationships between EOLD and staff hours to bed ratios, proportion of residents with dementia and staff attitudes. Conclusion: FCC facilitates a palliative approach to care. Future trials of case conferencing should consider outcomes and processes regarding decision making and planning for anticipated events and acute illness. Trial registration: Australian New Zealand Clinical Trial Registry ACTRN12612001164886