19,301 research outputs found
Magnetic properties of microtektites Semiannual status report, 1 Jan. - 31 Jun. 1969
Magnetic susceptibility, magnetization, and Curie constants for normal and bottle-green microtektites found in deep-sea sediment core
Physical aggression, compromised social support, and 10-year marital outcomes: Testing a relational spillover model
The purpose of the present study was to test a relational spillover model of physical aggression whereby physical aggression affects marital outcomes due to its effects on how spouses ask for and provide support to one another. Newlywed couples (n = 172) reported levels of physical aggression over the past year and engaged in interactions designed to elicit social support; marital adjustment, and stability were assessed periodically over the first 10 years of marriage. Multilevel modeling revealed that negative support behavior mediated the relationship between physical aggression and 10-year marital adjustment levels whereas positive support behavior mediated the relationship between physical aggression and divorce status. These findings emphasize the need to look beyond conflict when explaining how aggression affects relationships and when working with couples with a history of physical aggression who are seeking to improve their relationships
The development of a classification system for maternity models of care
© The Author(s) 2016. Background: A lack of standard terminology or means to identify and define models of maternity care in Australia has prevented accurate evaluations of outcomes for mothers and babies in different models of maternity care. Objective: As part of the Commonwealth-funded National Maternity Data Development Project, a classification system was developed utilising a data set specification that defines characteristics of models of maternity care. Method: The Maternity Care Classification System or MaCCS was developed using a participatory action research design that built upon the published and grey literature. Results: The study identified the characteristics that differentiate models of care and classifies models into eleven different Major Model Categories. Conclusion: The MaCCS will enable individual health services, local health districts (networks), jurisdictional and national health authorities to make better informed decisions for planning, policy development and delivery of maternity services in Australia
Giant viscosity enhancement in a spin-polarized Fermi liquid
The viscosity is measured for a Fermi liquid, a dilute He-He mixture,
under extremely high magnetic field/temperature conditions ( T, mK). The spin splitting energy is substantially greater than
the Fermi energy ; as a consequence the polarization tends to unity
and s-wave quasiparticle scattering is suppressed for . Using a
novel composite vibrating-wire viscometer an enhancement of the viscosity is
observed by a factor of more than 500 over its low-field value. Good agreement
is found between the measured viscosity and theoretical predictions based upon
a -matrix formalism.Comment: 4 pages, 4 figure
Estimating forest structure in a tropical forest using field measurements, a synthetic model and discrete return lidar data
Tropical forests are huge reservoirs of terrestrial carbon and are experiencing rapid degradation and deforestation. Understanding forest structure proves vital in accurately estimating both forest biomass and also the natural disturbances and remote sensing is an essential method for quantification of forest properties and structure in the tropics. Our objective is to examine canopy vegetation profiles formulated from discrete return LIght Detection And Ranging (lidar) data and examine their usefulness in estimating forest structural parameters measured during a field campaign. We developed a modeling procedure that utilized hypothetical stand characteristics to examine lidar profiles. In essence, this is a simple method to further enhance shape characteristics from the lidar profile. In this paper we report the results comparing field data collected at La Selva, Costa Rica (10° 26′ N, 83° 59′ W) and forest structure and parameters calculated from vegetation height profiles and forest structural modeling. We developed multiple regression models for each measured forest biometric property using forward stepwise variable selection that used Bayesian information criteria (BIC) as selection criteria. Among measures of forest structure, ranging from tree lateral density, diameter at breast height, and crown geometry, we found strong relationships with lidar canopy vegetation profile parameters. Metrics developed from lidar that were indicators of height of canopy were not significant in estimating plot biomass (p-value = 0.31, r2 = 0.17), but parameters from our synthetic forest model were found to be significant for estimating many of the forest structural properties, such as mean trunk diameter (p-value = 0.004, r2 = 0.51) and tree density (p-value = 0.002, r2 = 0.43). We were also able to develop a significant model relating lidar profiles to basal area (p-value = 0.003, r2 = 0.43). Use of the full lidar profile provided additional avenues for the prediction of field based forest measure parameters. Our synthetic canopy model provides a novel method for examining lidar metrics by developing a look-up table of profiles that determine profile shape, depth, and height. We suggest that the use of metrics indicating canopy height derived from lidar are limited in understanding biomass in a forest with little variation across the landscape and that there are many parameters that may be gleaned by lidar data that inform on forest biometric properties
C4 olefin conversion on reduced nickel y faujasite. Evidence for C5 olefin formation via C4 olefin disproportionation
Flux Tube Zero-Point Motion, Hadronic Charge Radii, and Hybrid Meson Production Cross Sections
Flux tube zero-point motion produces quark displacements transverse to the
flux tube which make significant contributions to hadronic charge radii. In
heavy quark systems, these contributions can be related by Bjorken's sum rule
to the rates for semileptonic decay to hybrid mesons. This connection can be
generalized to other leptoproduction processes, where transverse contributions
to elastic form factor slopes are related to the cross sections for the
production of the associated hybrid states. I identify the flux tube overlap
integral responsible for these effects as the strong QCD analogue of the
Sudakov form factor of perturbative QCD.Comment: 16 pages, revised to clarify some points and to improve and correct
the notation for the flux tube wave function
Tilt Induced Localization and Delocalization in the Second Landau Level
We have investigated the behavior of electronic phases of the second Landau
level under tilted magnetic fields. The fractional quantum Hall liquids at
2+1/5 and 2+4/5 and the solid phases at 2.30, 2.44, 2.57, and 2.70
are quickly destroyed with tilt. This behavior can be interpreted as a tilt
driven localization of the 2+1/5 and 2+4/5 fractional quantum Hall liquids and
a delocalization through melting of solid phases in the top Landau level,
respectively. The evolution towards the classical Hall gas of the solid phases
is suggestive of antiferromagnetic ordering
Production of Secondary Organic Aerosol During Aging of Biomass Burning Smoke From Fresh Fuels and Its Relationship to VOC Precursors
After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog-chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high-resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low-volatility POA as a reference standard (akin to a naturally occurring internal standard). These smoke aging experiments revealed variable organic aerosol (OA) enhancements, even for smoke from similar fuels and aging mechanisms. This variable OA enhancement correlated well with measured differences in the amounts of emitted volatile organic compounds (VOCs) that could subsequently be oxidized to form SOA. For some aging experiments, we were able to predict the SOA production to within a factor of 2 using a fuel-specific VOC emission inventory that was scaled by burn-specific toluene measurements. For fires of coniferous fuels that were dominated by needle burning, volatile biogenic compounds were the dominant precursor class. For wiregrass fires, furans were the dominant SOA precursors. We used a POA tracer ion to calculate the amount of mass lost due to gas-phase oxidation and subsequent volatilization of semivolatile POA. Less than 5% of the POA mass was lost via multiphase oxidation-driven evaporation during up to 2 hr of equivalent atmospheric oxidation
Feasibility of measuring sedentary time with thigh worn accelerometry and sociodemographic correlates: the 1970 British Cohort Study
In large scale cohort studies sedentary behaviour has been routinely measured using self-report or devices that apply count-based threshold. We employed a gold standard postural allocation technique using thigh inclination and acceleration to capture free-living sedentary behaviour . Participants (n=5,346, aged 46.8 ± 0.7 yrs) from the 1970 British Cohort study (U.K.) were fitted with a water-proofed thigh mounted accelerometer device (activPAL3 micro) worn continuously over 7 days, collected 2016 – 2018. Useable data were retrieved in 83.0% of the devices fitted, with 79.6% of the sample recording at least 6 full days of wear (at least 10 waking hours). Total daily sitting time (average 9.5±2.0 hr/d men and 9.0±2.0 hr/d women) accounted for 59.4% and 57.3% of waking hours in men and women respectively; 73.8% of the sample recorded ≥8hr/d of sitting. Sitting in prolonged bouts of more than 60 continuous minutes accounted for 25.3 % and 24.4% of total daily sitting in men and women respectively. In mutually adjusted models, male sex, underweight and obesity, education, poor self-rated health, TV-viewing time and a sitting occupation were associated with higher device measured sitting times. Thigh worn accelerometry was feasibly deployed and should be considered for larger scale national surveys
- …