4,193 research outputs found
Complexities associated with nucleation of water and ice from jet fuel in aircraft fuel systems: A critical review
The contamination and behaviour of water in aircraft fuel systems remains a significant global research interest following several aircraft incidents. To engineer a solution to the problem of icing in jet fuel, it is crucial to precisely identify the conditions and features that may exacerbate this phenomenon. This review will aid prospective researchers to identify work that has been done and work that is yet to be available for future study.
In this review, conclusive data integrating a wide range of literature and also providing an in-depth description of the factors that influence the behaviour of trace water, ice formation in jet fuels was carefully summarised. On investigational studies, it was discovered that to date, no work is available that studies the impact of sustainable jet fuel and its blends on ice formation, size and frequency distribution of dispersed water droplets in aircraft fuel systems. Findings from comparative studies also reveal that surfaces will have an essential role in the growth pattern of ice in aircraft fuel systems. Furthermore, findings show that supercooled water droplets with sizes greater than or equal to 5 µm can induce ice accretion.
This review identified a common problem with the prominent methods of reporting results as a graphically fitted plot. Subsequently, it proposed that authors of any original technical work provide raw data as supplementary information to allow comprehensibility. The study further offers a system that could help manage the nature of ice in aircraft fuel tank systems—making it readily available and accessible
Jets and Topography: Jet Transitions and the Impact on Transport in the Antarctic Circumpolar Current
The Southern Ocean’s Antarctic Circumpolar Current (ACC) naturally lends itself to interpretations using a zonally averaged framework. Yet, navigation around steep and complicated bathymetric obstacles suggests that local dynamics may be far removed from those described by zonally symmetric models. In this study, both observational and numerical results indicate that zonal asymmetries, in the form of topography, impact global flow structure and transport properties.
The conclusions are based on a suite of more than 1.5 million virtual drifter trajectories advected using a satellite altimetry–derived surface velocity field spanning 17 years. The focus is on sites of “cross front” transport as defined by movement across selected sea surface height contours that correspond to jets along most of the ACC. Cross-front exchange is localized in the lee of bathymetric features with more than 75% of crossing events occurring in regions corresponding to only 20% of the ACC’s zonal extent.
These observations motivate a series of numerical experiments using a two-layer quasigeostrophic model with simple, zonally asymmetric topography, which often produces transitions in the front structure along the channel. Significantly, regimes occur where the equilibrated number of coherent jets is a function of longitude and transport barriers are not periodic. Jet reorganization is carried out by eddy flux divergences acting to both accelerate and decelerate the mean flow of the jets. Eddy kinetic energy is amplified downstream of topography due to increased baroclinicity related to topographic steering. The combination of high eddy kinetic energy and recirculation features enhances particle exchange. These results stress the complications in developing consistent circumpolar definitions of the ACC fronts
The Iowa Homemaker vol.18, no.2
Special Invitation for One by Jane Helser, page 2
Whether Dress or Mate – Investigate by Dorothy Goeppinger, page 3
A Petition to Play by Ruth Sawin, page 4
Hold Your Horses by Berniece Williams, page 5
Fashion Maypole by Barbara Field, page 6
“Veishea-timing” by Beth Cummings, page 8
Learn All to Do All by Alvina Iverson, page 9
Fifty Grads Go to Work by Faithe Danielson, page 10
Throwing Bouquets by Winnifred Cannon, page 11
What’s New in Home Economics edited by Marjorie Pettinger, page 12
Behind Bright Jackets edited by Winnifred Cannon, page 14
Pie for All by Evelyn Burchard, page 15
“You Can’t Print That!” by Beth Johnson, page 16
Homemaking in the Hills by Carolyn Roller, page 17
Dear Someone, by Helen Greene, page 18
Picnic Precautions by Ida Halpin, page 20
Browned With Precision by Anne Halder Allen, page 21
From Carving to Kitchens by Ruth Dahlberg, page 22
Busy Summering by Betty Burbank and Henrietta Dunlop, page 23
Bowls With a Past by Jean Metcalf, page 2
Recommended from our members
Implementation of U.K. Earth system models for CMIP6
We describe the scientific and technical implementation of two models for a core set of
experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6).
The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the
Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to
HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data)
and initial conditions.We outline the scientific rationale and assumptions made in specifying these.
Notable details of the implementation include an ozone redistribution scheme for prescribed ozone
simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use
change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in
the simulation of background natural vegetation.We discuss the implications of these decisions for
interpretation of the simulation results. These simulations are expensive in terms of human and CPU
resources and will underpin many further experiments; we describe some of the technical steps taken to
ensure their scientific robustness and reproducibility
Long-Term Complications of Ebola Virus Disease: Prevalence and Predictors of Major Symptoms and the Role of Inflammation
Background
Cohort studies have reported a high prevalence of musculoskeletal, neurologic, auditory, and visual complications among Ebola virus disease (EVD) survivors. However, little is known about the host- and disease-related predictors of these symptoms and their etiological mechanisms.
Methods
The presence and patterns of 8 cardinal symptoms that are most commonly reported following EVD survival were assessed in the 326 EVD survivors who participated in the ongoing longitudinal Liberian EVD Survivor Study. At quarterly study visits, symptoms that developed since acute EVD were recorded and blood was collected for biomarkers of inflammation and immune activation.
Results
At baseline (mean 408 days from acute EVD), 75.5% of survivors reported at least 1 new cardinal symptom since surviving EVD, which in 85.8% was rated as highly interfering with life. Two or more incident symptoms were reported by 61.0% of survivors, with pairings of joint pain, headache, or fatigue the most frequent. Women were significantly more likely than men to report headache, while older age was significantly associated with musculoskeletal and visual symptoms. In analyses adjusted for multiple comparisons, no statistically significant association was found between any symptom and 26 markers of inflammation and immune activation. Symptom frequency remained largely unchanged during study follow-up.
Conclusions
Post-EVD complications occur in a majority of survivors and remain present more than 4 years after acute infection. An association between markers of inflammation and immune activation and individual symptoms was not found, suggesting an alternative etiology for persistent post-EVD symptomatology
The Mice at play in the CALIFA survey: A case study of a gas-rich major merger between first passage and coalescence
We present optical integral field spectroscopy (IFS) observations of the
Mice, a major merger between two massive (>10^11Msol) gas-rich spirals NGC4676A
and B, observed between first passage and final coalescence. The spectra
provide stellar and gas kinematics, ionised gas properties and stellar
population diagnostics, over the full optical extent of both galaxies. The Mice
provide a perfect case study highlighting the importance of IFS data for
improving our understanding of local galaxies. The impact of first passage on
the kinematics of the stars and gas has been significant, with strong bars
likely induced in both galaxies. The barred spiral NGC4676B exhibits a strong
twist in both its stellar and ionised gas disk. On the other hand, the impact
of the merger on the stellar populations has been minimal thus far: star
formation induced by the recent close passage has not contributed significantly
to the global star formation rate or stellar mass of the galaxies. Both
galaxies show bicones of high ionisation gas extending along their minor axes.
In NGC4676A the high gas velocity dispersion and Seyfert-like line ratios at
large scaleheight indicate a powerful outflow. Fast shocks extend to ~6.6kpc
above the disk plane. The measured ram pressure and mass outflow rate
(~8-20Msol/yr) are similar to superwinds from local ULIRGs, although NGC4676A
has only a moderate infrared luminosity of 3x10^10Lsol. Energy beyond that
provided by the mechanical energy of the starburst appears to be required to
drive the outflow. We compare the observations to mock kinematic and stellar
population maps from a merger simulation. The models show little enhancement in
star formation during and following first passage, in agreement with the
observations. We highlight areas where IFS data could help further constrain
the models.Comment: 23 pages, 13 figures, accepted to A&A. A version with a complete set
of high resolution figures is available here:
http://www-star.st-and.ac.uk/~vw8/resources/mice_v8_astroph.pd
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.
Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes
- …