The successful detection of gravitational waves from astrophysical sources carried out by the laser interferometric detectors LIGO and Virgo have stimulated scientists to develop a new generation of ...more sensitive gravitational wave detectors. In the proposed upgrade called LIGO Voyager, silicon test masses will be cooled to cryogenic temperatures. To provide heat removal from the test masses when they absorb the laser light one can increase their thermal emissivity using a special black coating. We have studied mechanical losses in a carbon nanotube black coating deposited on silicon wafers. The additional thermal noise associated with mechanical loss in this coating was calculated using a value of the product of the coating Young's modulus and the coating mechanical loss angle determined from the measurements. It was found that at temperatures of about 123 K, the additional thermal noise of the LIGO Voyager test mass caused by the carbon nanotube black coating deposited on its barrel is less than the noise associated with the Acktar Black coating and is 20 times less than the noise due to the optical high reflective (HR) coating of the test mass.
The detection of gravitational waves from compact binary mergers by LIGO has opened the era of gravitational wave astronomy, revealing a previously hidden side of the cosmos. To maximize the reach of ...the existing LIGO observatory facilities, we have designed a new instrument able to detect gravitational waves at distances 5 times further away than possible with Advanced LIGO, or at greater than 100 times the event rate. Observations with this new instrument will make possible dramatic steps toward understanding the physics of the nearby Universe, as well as observing the Universe out to cosmological distances by the detection of binary black hole coalescences. This article presents the instrument design and a quantitative analysis of the anticipated noise floor.
No safe level of lead in blood has been identified. Blood lead testing is required for children on Medicaid, but it is at the discretion of providers and parents for others. Elevated blood lead ...levels (EBLLs) cannot be identified in children who are not tested.
The aims of this research were to identify determinants of lead testing and EBLLs among North Carolina children and estimate the number of additional children with EBLLs among those not tested.
We linked geocoded North Carolina birth certificates from 2011-2016 to 2010 U.S. Census data and North Carolina blood lead test results from 2011-2018. We estimated the probability of being screened for lead and created inverse probability (IP) of testing weights. We evaluated the risk of an EBLL of
at
of age, conditional on characteristics at birth, using generalized linear models and then applied IP weights to account for missing blood lead results among unscreened children. We estimated the number of additional children with EBLLs of all North Carolina children using the IP-weighted population and bootstrapping to produce 95% credible intervals (CrI).
Mothers of the 63.5% of children (402,002 of 633,159) linked to a blood lead test result were disproportionately young, Hispanic, Black, American Indian, or on Medicaid. In full models, maternal age
; 95% confidence interval (CI): 1.13, 1.20 or smoking (
1.14; 95% CI: 1.12, 1.17); proximity to a major roadway (
1.10; 95% CI: 1.05, 1.15); proximity to a lead-releasing Toxics Release Inventory site (
1.08; 95% CI: 1.03, 1.14) or a National Emissions Inventory site (
1.11; 95% CI: 1.07, 1.14); and living in neighborhoods with more housing built before 1950 (
1.10; 95% CI: 1.05, 1.14) or before 1940 (
1.18; 95% CI: 1.11, 1.25) or more vacant housing (
1.14; 95% CI: 1.11, 1.17) were associated with an increased risk of EBLL, whereas overlap with a public water service system was associated with a decreased risk of EBLL (
0.85; 95% CI: 0.83, 0.87). Children of Black mothers were no more likely than children of White mothers to have EBLLs (
0.98; 95% CI: 0.96, 1.01). Complete blood lead screening in 2011-2018 may have identified an additional 17,543 (95% CrI: 17,462, 17,650) children with EBLLs
.
Our results indicate that current North Carolina lead screening strategies fail to identify over 30% (17,543 of 57,398) of children with subclinical lead poisoning and that accounting for characteristics at birth alters the conclusions about racial disparities in children's EBLLs. https://doi.org/10.1289/EHP10335.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
The presented study explores the prediction of soil water retention and its variability from soil texture and bulk density measurements, using a physically-based scaling technique. Specifically, the ...Arya–Paris (AP) physico-empirical model is applied to two soil datasets that are collected from two catchments located in different areas of Southern Italy. Laboratory-measured soil water retention functions are scaled to characterize soil variability. The laboratory-measured and AP-predicted reference water retention functions are compared by evaluating the lognormal distribution of derived scaling factors, relative to the mean reference retention function. Since the scaling theory assumes geometric similitude for the investigated soils, successful application of using particle-size distribution to estimate soil water retention requires separation of soils with different textures, using variance analysis. We conclude that variability in soil water retention can be determined from limited soil water retention data using the scaling approach when combined with particle-size distribution measurements. This method can potentially be used as an effective tool for identifying soil hydrologic response at catchment scales.
Low and declining soil fertility has been recognized for a long time as a major impediment to intensifying agriculture in sub-Saharan Africa (SSA). Consequently, from the inception of international ...agricultural research, centres operating in SSA have had a research programme focusing on soil and soil fertility management, including the International Institute of Tropical Agriculture (IITA). The scope, content, and approaches of soil and soil fertility management research have changed over the past decades in response to lessons learnt and internal and external drivers and this paper uses IITA as a case study to document and analyse the consequences of strategic decisions taken on technology development, validation, and ultimately uptake by smallholder farmers in SSA. After an initial section describing the external environment within which soil and soil fertility management research is operating, various dimensions of this research area are covered: (i) 'strategic research', 'Research for Development', partnerships, and balancing acts, (ii) changing role of characterization due to the expansion in geographical scope and shift from soils to farms and livelihoods, (iii) technology development: changes in vision, content, and scale of intervention, (iv) technology validation and delivery to farming communities, and (v) impact and feedback to the technology development and validation process. Each of the above sections follows a chronological approach, covering the last five decades (from the late 1960s till today). The paper ends with a number of lessons learnt which could be considered for future initiatives aiming at developing and delivering improved soil and soil fertility management practices to smallholder farming communities in SSA.
Clinical guidelines have endorsed early palliative care for patients with advanced malignancies, but receipt remains low in the US. This study examined the association between Medicaid expansion ...under the Affordable Care Act and receipt of palliative care among patients newly diagnosed with advanced-stage cancers. Using the National Cancer Database, we found that the percentage of eligible patients who received palliative care as part of first-course treatment increased from 17.0 percent preexpansion to 18.9 percent postexpansion in Medicaid expansion states and from 15.7 percent to 16.7 percent, respectively, in nonexpansion states, resulting in a net increase of 1.3 percentage points in expansion states in adjusted analyses. Increases in receipt of palliative care associated with Medicaid expansion were largest for patients with advanced pancreatic, colorectal, lung, and oral cavity and pharynx cancers and non-Hodgkin lymphoma. Our findings suggest that increasing Medicaid coverage facilitates access to guideline-based palliative care for advanced cancer, and they provide additional evidence of benefit in cancer care from states' expansion of income eligibility for Medicaid.
NGA-West2 research project Bozorgnia, Yousef; Abrahamson, Norman A; Al Atik, Linda ...
Earthquake spectra,
08/2014, Letnik:
30, Številka:
3
Journal Article
Recenzirano
The NGA-West2 project is a large multidisciplinary, multi-year research program on the Next Generation Attenuation (NGA) models for shallow crustal earthquakes in active tectonic regions. The ...research project has been coordinated by the Pacific Earthquake Engineering Research Center (PEER), with extensive technical interactions among many individuals and organizations. NGA-West2 addresses several key issues in ground-motion seismic hazard, including updating the NGA database for a magnitude range of 3.0-7.9; updating NGA ground-motion prediction equations (GMPEs) for the "average" horizontal component; scaling response spectra for damping values other than 5%; quantifying the effects of directivity and directionality for horizontal ground motion; resolving discrepancies between the NGA and the National Earthquake Hazards Reduction Program (NEHRP) site amplification factors; analysis of epistemic uncertainty for NGA GMPEs; and developing GMPEs for vertical ground motion. This paper presents an overview of the NGA-West2 research program and its subprojects.
We propose a new framework to predict stellar properties from light curves.
We analyze the light-curve data from the Kepler space mission and develop a
novel tool for deriving the stellar rotation ...periods for main-sequence stars.
Using this tool, we provide the largest (108785 stars) and most accurate (an
average error of $1.6$ Days) sample of stellar rotations to date. Our model,
LightPred, is a novel deep-learning model designed to extract stellar rotation
periods from light curves. The model utilizes a dual-branch architecture
combining Long Short-Term Memory (LSTM) and Transformer components to capture
both temporal and global features within the data. We train LightPred on a
dataset of simulated light curves generated using a realistic spot model and
enhance its performance through self-supervised contrastive pre-training on
Kepler light curves. Our evaluation demonstrates that LightPred outperforms
classical methods like the Autocorrelation Function (ACF) in terms of accuracy
and robustness. We apply LightPred to the Kepler dataset, generating the
largest catalog to date of stellar rotation periods for main-sequence stars.
Our analysis reveals a systematic shift towards shorter periods compared to
previous studies, suggesting a potential revision of stellar age estimates. We
also investigate the impact of stellar activity on period determination and
find evidence for a distinct period-activity relation. Additionally, we confirm
tidal synchronization in eclipsing binaries with orbital periods shorter than
10 days. Our findings highlight the potential of deep learning in extracting
fundamental stellar properties from light curves, opening new avenues for
understanding stellar evolution and population demographics.
Two types of inductively coupled RF high-density plasmas designed for sputter deposition in an external magnetic field are studied experimentally. One is helicon wave excited plasma in a magnetic ...field for cylindrical target sputtering. The other is planar magnetron discharge assisted by an inductively coupled plasma. The plasmas are produced using helical antennas with azimuthal mode number of
m=0. Plasma characteristics are studied in Ar and reactive gases such as N
2, H
2 and/or O
2. An RF wave field is measured and the excitation of helicon waves in a magnetic field is clarified in the production of high-density plasmas. Spectroscopic measurement of plasma emissions in the planar magnetron discharges indicates remarkable increase of ionization of sputtered particles when it is assisted by an inductively coupled plasma.
This Horizon Study describes a next-generation ground-based gravitational-wave observatory: Cosmic Explorer. With ten times the sensitivity of Advanced LIGO, Cosmic Explorer will push ...gravitational-wave astronomy towards the edge of the observable universe (\(z \sim 100\)). The goals of this Horizon Study are to describe and evaluate design concepts for Cosmic Explorer; to plan for the United States' leadership in gravitational-wave astronomy; and to envisage the role of Cosmic Explorer in the international effort to build a "Third-Generation" (3G) observatory network that will make discoveries transformative across astronomy, physics, and cosmology.
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