2,906 research outputs found

    Small Engine Component Technology (SECT)

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    A study of small gas turbine engines was conducted to identify high payoff technologies for year-2000 engines and to define companion technology plans. The study addressed engines in the 186 to 746 KW (250 to 1000 shp) or equivalent thrust range for rotorcraft, commuter (turboprop), cruise missile (turbojet), and APU applications. The results show that aggressive advancement of high payoff technologies can produce significant benefits, including reduced SFC, weight, and cost for year-2000 engines. Mission studies for these engines show potential fuel burn reductions of 22 to 71 percent. These engine benefits translate into reductions in rotorcraft and commuter aircraft direct operating costs (DOC) of 7 to 11 percent, and in APU-related DOCs of 37 to 47 percent. The study further shows that cruise missile range can be increased by as much as 200 percent (320 percent with slurry fuels) for a year-2000 missile-turbojet system compared to a current rocket-powered system. The high payoff technologies were identified and the benefits quantified. Based on this, technology plans were defined for each of the four engine applications as recommended guidelines for further NASA research and technology efforts to establish technological readiness for the year 2000

    Space-based geoengineering: challenges and requirements

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    The prospect of engineering the Earth's climate (geoengineering) raises a multitude of issues associated with climatology, engineering on macroscopic scales, and indeed the ethics of such ventures. Depending on personal views, such large-scale engineering is either an obvious necessity for the deep future, or yet another example of human conceit. In this article a simple climate model will be used to estimate requirements for engineering the Earth's climate, principally using space-based geoengineering. Active cooling of the climate to mitigate anthropogenic climate change due to a doubling of the carbon dioxide concentration in the Earth's atmosphere is considered. This representative scenario will allow the scale of the engineering challenge to be determined. It will be argued that simple occulting discs at the interior Lagrange point may represent a less complex solution than concepts for highly engineered refracting discs proposed recently. While engineering on macroscopic scales can appear formidable, emerging capabilities may allow such ventures to be seriously considered in the long term. This article is not an exhaustive review of geoengineering, but aims to provide a foretaste of the future opportunities, challenges, and requirements for space-based geoengineering ventures

    Pengaruh Kualitas Pelayanan Program KB Terhadap Intensi Akseptor Dalam Pelaksanaan KB Mandiri Serta Alternatif Peningkatannya

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    ABSTRAK Dari segi kuantitas, keberhasilan program Keluarga Berencana (KB) di Indonesia telah diakui secara internasional. Program KB dikembangkan untuk menangani masalah ledakan penduduk yang semakin mendesak serta memerlukan pengalokasian dana besar dari pemerintah. Kebutuhan kontrasepsi dan pelayanan KB bagi sebagian besar akseptor masih hams disubsidi oleh pemerintah. Beban pengadaan kontrasepsi ini perlu diperkecil agar dana yang tersedia dapat digunakan untuk daerah atau segolongan masyarakat yang lebih memerlukan. Keluarga Berencana (KB) Mandiri merupakan salah satu upaya yang ditempuh pemerintah dalam pelaksanaan Program KB. Tujuan akhir KB Mandiri ialah peranserta masyarakat dalam melaksanakan KB atas dasar kesadaran, inisiatif, dan usaha sendiri. Dengan cara ini, akseptor diharapkan bisa membiayai sendiri semua kebutuhannya selama berpartisipasi dalam program KB. Konsep ini disusun karena keterbatasan subsidi dana pemerintah untuk pelaksanaan Program KB. Peningkatan kualitas pelayanan diasumsikan akan berpengaruh terhadap intensi kemandirian akseptor. Penelitian ini dibagi dalam dua tahap. Pertamaupaya menemukan besarnya pengaruh setiap aspek kualitas pelayanan terhadap intensi kemandirian akseptor. Kedua, upaya mencari alternatif solusi masalah. Hasil analisis skala pada tahap pertama adalah, aspek kualitas pemilihan metode merupakan prediktor yang baik untuk intensi akseptor dalam mengikuti KB Mandiri (F=2,622p=0,058 ). Dengan melihat hasil analisis regresi temyata aspek dapat memprediksi sekitar 27 % intensi akseptor dalam mengikuti KB Mandiri. Data penelitian diambil dari responden yang tinggal di Daerah Tingkat H Kabupaten Sleman dan Kotamadya Yogyakarta. Teknik pengambilan sampel yang digunakan dalam penelitian adalah purposive sampling. Pengumpulan data dilakukan dengan menggunakan skala, interview, dan studi pustaka. Analisis data dilakukan dengan menggunakan produk moment dan teknik analisis regresi

    Sweet flowers are slow and weeds make haste: anthropogenic dispersal of plants via garden and construction soil

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    This is the final version of the article. Available from Oxford University Press via the DOI in this record.Anthropogenic activities are increasingly responsible for the dispersal of plants. Of particular concern is anthropogenic dispersal of problematic invasive non-native plants. A common dispersal vector is the movement of soil containing seeds or rhizomes. Housing development and domestic gardening activities cause large quantities of soil to be moved, and understanding the role of these activities is critical for informing policy and management to reduce the spread of problematic plants. Here, by collecting soil samples being moved for housing development and domestic gardening, and observing the species that germinated from these samples, we determined the quantities and invasive status of plants moved. From our samples nearly 2000 individuals representing 90 species germinated. Our results suggest that given the quantity of topsoil needed to cover an average-sized UK garden (190 m2 ), there could be 2.2 million and c.2 million viable seeds in soil sourced from housing developments and gardens, respectively. In both housing development and garden samples, native species were more abundant and species-rich than non-native naturalised and invasive species. Buddleia (an invasive) was the most common species overall and in garden samples; this is likely due to multiple traits that adapt it to dispersal, such as prolific seed production. The abundance of invasive and naturalised species was significantly higher in garden than in housing development samples, suggesting that informal movement of soil between gardens poses a greater risk of spreading invasive plants than commercial sources. Consequences for models predicting future distributions of plants, and strategies to mitigate anthropogenic dispersal of problematic plants are considered.This project was funded by the University of Exeter and the Animal and Plant Health Agency. We are grateful to all who gave samples for this study

    Is early center-based child care associated with tantrums and unmanageable behavior over time up to school entry?

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    Background. Existing research suggests that there is a relationship between greater exposure to center-based child care and child behavioral problems though the mechanism for the impact is unclear. However the measure used to document child care has usually been average hours, which may be particularly unreliable in the early months when fewer children are in center care. In addition individual trajectories for behavior difficulties have not been studied. Objective. The purpose of the current study was to examine whether the extent of exposure to center-based child care before two years predicted the trajectory of childrenā€™s difficult behavior (i.e., tantrums and unmanageable behavior) from 30 to 51 months controlling for child and maternal characteristics. Method. Data were drawn from UK-based Families, Children and Child Care (FCCC) study (n=1201). Individual growth models were fitted to test the relation between early center-based child care experiences and subsequent difficult behavior. Results. Children with more exposure to center-based care before two had less difficult behavior at 30 months, but more increase over time. Initial levels were predicted by higher difficult temperament and lower verbal ability. Higher difficult temperament and lower family socio-economic status predicted its change over time. Conclusion. Findings suggest that early exposure to center-based care before two years old is a risk factor for subsequent behavior problems especially when children have a longer period of exposure. A possible explanatory process is that child coping strategies to manage frustration are less well developed in a group context, especially when they lag behind in expressive language

    Dead cetacean? beach, bloat, float, sink

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    Ā© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Moore, M. J., Mitchell, G. H., Rowles, T. K., & Early, G. Dead cetacean? beach, bloat, float, sink. Frontiers in Marine Science, 7, (2020): 333, doi:10.3389/fmars.2020.00333.Variably buoyant, dead Cetacea may float, or sink and later bloat to refloat if ambient temperature and pressure allow sufficient decomposition gas formation and expansion. Mortality can result from acute or chronic disease, fishery entanglement, vessel collision, noxious noises, or toxicant spills. Investigators often face the daunting task of elucidating a complex series of events, in reverse order, from when and where an animal is found, and to diagnose the cause of death. Various scenarios are possible: an animal could die at sea remaining there or floating ashore, or strand on a beach alive, where it dies and, if cast high enough, remain beached to be scavenged or decompose. An animal that rests low on a beach may refloat again, through increased buoyancy from decomposition gas and favorable tides, currents, and wind. Here we review the factors responsible for the different outcomes, and how to recognize the provenance of a cetacean mortality found beached, or floating at sea. In conclusion, only some carcasses strand, or remain floating. Negatively buoyant animals that die at depth, or on the surface, and sink, may never surface, even after decomposition gas accumulation, as in cold, deep waters gas may fail to adequately reduce the density of a carcass, precluding it from returning to the surface

    The quality of different types of child care at 10 and 18 months. A comparison between types and factors related to quality.

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    The quality of care offered in four different types of non-parental child care to 307 infants at 10 months old and 331 infants at 18 months old was compared and factors associated with higher quality were identified. Observed quality was lowest in nurseries at each age point, except that at 18 months they offered more learning activities. There were few differences in the observed quality of care by child-minders, grandparents and nannies, although grandparents had somewhat lower safety and health scores and offered children fewer activities. Cost was largely unrelated to quality of care except in child-minding, where higher cost was associated with higher quality. Observed ratios of children to adults had a significant impact on quality of nursery care; the more infants or toddlers each adult had to care for, the lower the quality of the care she gave them. Mothers' overall satisfaction with their child's care was positively associated with its quality for home-based care but not for nursery settings

    Autopsy Standardized Mortality Review: A Pilot Study Offering a Methodology for Improved Patient Outcomes

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    A standardized mortality review of hospital autopsies identified discrepancies between clinical diagnoses and autopsy findings, unexpected deaths, adequacy of diagnostic workup, presence of adverse event, and type of a quality issue if present. The standardized review elements were chosen based on a review of quality metrics commonly used by hospitals. The review was completed by the pathologist based on their initial autopsy findings. The final autopsy report was later reviewed to confirm the initial review findings. Major discrepancies in diagnosis were categorized as class I or II based on the modified Goldman criteria. Ninety-six hospital autopsy cases from January 2015 to February 2018 were included in the study. The overall major discrepancy rate was 27%. Class I discrepancies, where a diagnosis found at autopsy might have improved survival had it been made premortem, were identified in 16% of cases. Categories associated with increased discrepancy rates included unexpected deaths, inadequate workup, abnormal labs or imaging not addressed, and certain quality issues. Deaths not expected at admission but expected at the time of death, those with adverse events, those within 48 hours of a procedure, those within 48 hours of admission, those with physician-specific quality issues, and those with system or process issues were not significantly related to diagnostic accuracy

    Phase separation transition in liquids and polymers induced by electric field gradients

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    Spatially uniform electric fields have been used to induce instabilities in liquids and polymers, and to orient and deform ordered phases of block-copolymers. Here we discuss the demixing phase transition occurring in liquid mixtures when they are subject to spatially nonuniform fields. Above the critical value of potential, a phase-separation transition occurs, and two coexisting phases appear separated by a sharp interface. Analytical and numerical composition profiles are given, and the interface location as a function of charge or voltage is found. The possible influence of demixing on the stability of suspensions and on inter-colloid interaction is discussed.Comment: 7 pages, 3 figures. Special issue of the J. Phys. Soc. Ja
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