4,951 research outputs found
Porous silica spheres as indoor air pollutant scavengers
Porous silica spheres were investigated for their effectiveness in removing typical indoor air pollutants, such as aromatic and carbonyl-containing volatile organic compounds (VOCs), and compared to the commercially available polymer styrene-divinylbenzene (XAD-4). The silica spheres and the XAD-4 resin were coated on denuder sampling devices and their adsorption efficiencies for volatile organic compounds evaluated using an indoor air simulation chamber. Real indoor sampling was also undertaken to evaluate the affinity of the silica adsorbents for a variety of indoor VOCs. The silica sphere adsorbents were found to have a high affinity for polar carbonyls and found to be more efficient than the XAD-4 resin at adsorbing carbonyls in an indoor environment
The Attitudes about Complex Therapy Scale (ACTS) in Type 2 Diabetes and Cardiovascular Disease: Development, Validity and Reliability
Background: Type 2 diabetes is associated with cardiovascular disease, and patients with both conditions are prescribed complex medication regimens.
Aim: The aim was to develop a reliable and valid measure of attitudes associated with the prescription and management of multiple medicines in patients with Type 2 diabetes and cardiovascular disease.
Methods: Principal component analysis (PCA) and Cronbach alpha assessed the reliability of the Attitudes about Complex Therapy Scale (ACTS). Examinations of relationships with related measures inform concurrent validity. Questionnaires were sent to a cross-sectional sample of 480 people prescribed multiple medicines for co-morbid Type 2 diabetes.
Results: Cronbach alpha was 0.76, indicating the scale had good internal reliability. PCA rotated a four factor model accounting for 37% of the variance. Four subscales identified; 1. Concerns about multiple medicines and increasing numbers of medicines; 2.Anxiety over missed medicines; 3. Desires to substitute medicines and reduce the number of medicines prescribed and; 4. Perceptions related to organising and managing complex therapy. The ACTS showed significant relationships with measures of anxiety, depression, general beliefs about medicines and self-efficacy. Also, the ACTS significantly correlated with adherence to medicines, showing good predictive validity.
Conclusion: The ACTS was designed to assess negative attitudes towards complex therapy and multiple medication management. This tool could aid prescribing decisions and may identify people who are intentionally non-adherent to all or some of their medicines
Collaborative Research: Locating the Mantle Component in Granite
Granitic plutons of the Coastal Maine Magmatic Province (CMMP) commonly display dramatic field relations that record interaction between magmas of markedly different composition (chemical and isotopic) and physical properties. Silicic magma chambers, derived from the crust, received influxes of denser mafic magma that spread out along the floor of these chambers to produce a compositional stratification know as Mafic and Silicic Layered Intrusions (MASLI). The spectacular field relations and large compositional variation in the vicinity of the interface between contrasting magma types are well document by recent studies. In contrast, the extent of physical and chemical coupling between the base of the chamber, that receives mafic influx, and the overlying silicic magma remains poorly understood. Three known or presumed MASLI plutons in the CMMP, the Vinalhaven, Deer Isle, and Mt. Waldo granites, have been selected for study to address this important issue. Specifically, what processes and other factors determine the extent to which heat and material are exchanged between contrasting magma types? Is heat and mass subsequently distributed to the upper reaches of the chamber? By combining textural, compositional and isotopic studies of zoned plagioclase and accessory minerals (using electron and ion-microprobe techniques), along with data for magmatic enclaves from each of the granites, the relative timing and extent of variation in composition of the magma from with individual minerals crystallized can be assessed. Comparison of internal variations among adjacent mineral grains will be used to constrain the relative extent to which material is redistributed within the chamber. Furthermore, studies such as this will enhance our understanding of magma chamber dynamics and growth, enable recognition of the contribution of mantle and crustal components in granite petrogenesis, and evaluate models for the growth and evolution of continental lithosphere
Structural behaviour of copper chloride catalysts during the chlorination of CO to phosgene
The interaction of CO with an attapulgite-supported Cu(II)Cl2 catalyst has been examined in a micro-reactor arrangement. CO exposure to the dried, as-received catalyst at elevated temperatures leads to the formation of CO2 as the only identifiable product. However, phosgene production can be induced by a catalyst pre-treatment where the supported Cu(II)Cl2 sample is exposed to a diluted stream of chlorine. Subsequent CO exposure at ~ 370°C then leads to phosgene production. In order to investigate the origins of this atypical set of reaction characteristics, a series of x-ray absorption experiments were performed that were supplemented by DFT calculations. XANES measurements establish that at the elevated temperatures connected with phosgene formation, the catalyst is comprised of Cu+ and a small amount of Cu2+. Moreover, the data show that unique to the chlorine pre-treated sample, CO exposure at elevated temperature results in a short-lived oxidation of the copper. On the basis of calculated CO adsorption energies, DFT calculations indicate that a mixed Cu+/Cu2+ catalyst is required to support CO chemisorption
The Physics of Supernova Remnant Blast Waves. I. Kinematics of DEM L71 in the Large Magellanic Cloud
We present the results from Fabry-Perot imaging spectroscopy of the
Balmer-dominated supernova remnant DEM L71 (0505-67.9) in the LMC. Spectra
extracted from the entire circumference of the blast wave reveal the broad and
narrow component H-alpha line emission characteristic of non-radiative shocks
in partially neutral gas. The new spectra of DEM L71 include portions of the
rim that have not been previously observed. We find that the broad component
width varies azimuthally along the edge of DEM L71, ranging from 450+/-60 km/s
along the eastern edge to values as high as 985 (+210)(-165) km/s along the
faint western edge. In part of the faint northern rim the broad component is
not detected, possibly indicating a lower density in these regions and/or a
broad component width in excess of 1000 km/s. Between the limits of zero and
full electron-ion temperature equilibration at the shock front, the allowed
range of shock velocities is 430-560 km/s along the east rim and 700-1250 km/s
along other parts of the blast wave. The H-alpha broad-to-narrow flux ratios
vary considerably around the remnant, ranging from 0.4 to 0.8. These ratios lie
below the values predicted by our shock models. We find that narrow component
H-alpha emission from a cosmic ray precursor may be the cause of the
discrepancy. The least decelerated portions of the blast wave (i.e., regions
excluding the brightest filaments) are well characterized by Sedov models with
a kinetic energy E_51= (0.37+/-0.06)*D_50**(5/2), where D_50 is the LMC
distance in units of 50 kpc. The corresponding age for DEM L71 is
(4360+/-290)*D_50 yr. This is the first time that velocity information from the
entire blast wave has been utilized to study the global kinematics of a
non-radiative SNR at a known distance.Comment: 21 pages, including 8 postscript figures and 4 tables, LaTeX,
accepted to ApJ; see companion pape
Globular Cluster and Galaxy Formation: M31, the Milky Way and Implications for Globular Cluster Systems of Spiral Galaxies
The globular cluster (GC) systems of the Milky Way and of our neighboring
spiral galaxy, M31, comprise 2 distinct entities, differing in 3 respects. 1.
M31 has young GCs, ages from ~100 Myr to 5 Gyr old, as well as old globular
clusters. No such young GCs are known in the Milky Way. 2. We confirm that the
oldest M31 GCs have much higher nitrogen abundances than do Galactic GCs at
equivalent metallicities. 3. Morrison et al. found M31 has a subcomponent of
GCs that follow closely the disk rotation curve of M31. Such a GC system in our
own Galaxy has yet to be found. These data are interpreted in terms of the
hierarchical-clustering-merging (HCM) paradigm for galaxy formation. We infer
that M31 has absorbed more of its dwarf systems than has the Milky Way. This
inference has 3 implications: 1. All spiral galaxies likely differ in their GC
properties, depending on how many companions each galaxy has, and when the
parent galaxy absorbs them. The the Milky Way ties down one end of this
spectrum, as almost all of its GCs were absorbed 10-12 Gyr ago. 2. It suggests
that young GCs are preferentially formed in the dwarf companions of parent
galaxies, and then absorbed by the parent galaxy during mergers. 3. Young GCs
seen in tidally-interacting galaxies might come from dwarf companions of these
galaxies, rather than be made a-new in the tidal interaction. There is no ready
explanation for the marked difference in nitrogen abundance for old M31 GCs
relative to the oldest Galactic GCs. The predictions made by Li & Burstein
regarding the origin of nitrogen abundance in globular clusters are consistent
with what is found for the old M31 GCs compared to that for the two 5 Gyr-old
M31 GCs.Comment: to be published in ApJ, Oct 2004; 13 pages of text, 2 tables, 7
postscript figure
The HST Key Project on the Extragalactic Distance Scale. XXII. The Discovery of Cepheids in NGC 1326-A
We report on the detection of Cepheids and the first distance measurement to
the spiral galaxy NGC 1326-A, a member of the Fornax cluster of galaxies. We
have employed data obtained with the Wide Field and Planetary Camera 2 on board
the Hubble Space Telescope. Over a 49 day interval, a total of twelve V-band
(F555W) and eight I-band (F814W) epochs of observation were obtained. Two
photometric reduction packages, ALLFRAME and DoPHOT, have been employed to
obtain photometry measures from the three Wide Field CCDs. Variability analysis
yields a total of 17 Cepheids in common with both photometry datasets, with
periods ranging between 10 and 50 days. Of these 14 Cepheids with high-quality
lightcurves are used to fit the V and I period-luminosity relations and derive
apparent distance moduli, assuming a Large Magellanic Cloud distance modulus
(m-M) (LMC) = 18.50 +- 0.10 mag and color excess E(B-V) = 0.10 mag. Assuming
A(V)/E(V-I) = 2.45, the DoPHOT data yield a true distance modulus to NGC 1326-A
of (m-M)_0 = 31.36 +- 0.17 (random) +- 0.13 (systematic) mag, corresponding to
a distance of 18.7 \pm 1.5 (random) \pm 1.2 (systematic) Mpc. The derived
distance to NGC 1326-A is in good agreement with the distance derived
previously to NGC 1365, another spiral galaxy member of the Fornax cluster.
However the distances to both galaxies are significantly lower than to NGC
1425, a third Cepheid calibrator in the outer parts of the cluster.Comment: 33 pages A gzipped tar file containing 12 figures can be obtained
from http://www.ipac.caltech.edu/H0kp/n1326a/n1326a.htm
ResearchCOVIDâ19 Preparedness in Michigan Nursing Homes
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155466/1/jgs16490_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155466/2/jgs16490.pd
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