1,065 research outputs found
Aerosol Lidar and MODIS Satellite Comparisons for Future Aerosol Loading Forecast
Knowledge of the concentration and distribution of atmospheric aerosols using both airborne lidar and satellite instruments is a field of active research. An aircraft based aerosol lidar has been used to study the distribution of atmospheric aerosols in the California Central Valley and eastern US coast. Concurrently, satellite aerosol retrievals, from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra and Aqua satellites, were take over the Central Valley. The MODIS Level 2 aerosol data product provides retrieved ambient aerosol optical properties (e.g., optical depth (AOD) and size distribution) globally over ocean and land at a spatial resolution of 10 km. The Central Valley topography was overlaid with MODIS AOD (5x5 sq km resolution) and the aerosol scattering vertical profiles from a lidar flight. Backward air parcel trajectories for the lidar data show that air from the Pacific and northern part of the Central Valley converge confining the aerosols to the lower valley region and below the mixed layer. Below an altitude of 1 km, the lidar aerosol and MODIS AOD exhibit good agreement. Both data sets indicate a high presence of aerosols near Bakersfield and the Tehachapi Mountains. These and other results to be presented indicate that the majority of the aerosols are below the mixed layer such that the MODIS AOD should correspond well with surface measurements. Lidar measurements will help interpret satellite AOD retrievals so that one day they can be used on a routine basis for prediction of boundary layer aerosol pollution events
ITR/PE+SY digital clay for shape input and display
Issued as final reportNational Science Foundatio
Seasonal Toxicity Observed with Amphipods (Eohaustorius estuarius) at Paleta Creek, San Diego Bay, USA
To assess potential impacts on receiving systems, associated with storm water contaminants, laboratory 10‐d amphipod (Eohaustorius estuarius) survival toxicity tests were performed using intact sediment cores collected from Paleta Creek (San Diego Bay, CA, USA) on 5 occasions between 2015 and 2017. The approach included deposition‐associated sediment particles collected from sediment traps placed at each of 4 locations during the 2015 to 2016 wet seasons. The bioassays demonstrated wet season toxicity, especially closest to the creek mouth, and greater mortality associated with particles deposited in the wet season compared with dry season samples. Grain size analysis of sediment trap material indicated coarser sediment at the mouth of the creek and finer sediment in the outer depositional areas. Contaminant concentrations of metals (Cd, Cu, Hg, Ni, Pb, and Zn) and organic compounds (polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], and pesticides) were quantified to assess possible causes of toxicity. Contaminant concentrations were determined in the top 5 cm of sediment and porewater (using passive samplers). Whereas metals, PAHs, and PCBs were rarely detected at sufficient concentrations to elicit a response, pyrethroid pesticides were highly correlated with amphipod toxicity. Summing individual pyrethroid constituents using a toxic unit approach suggested that toxicity to E. estuarius could be associated with pyrethroids. This unique test design allowed delineation of spatial and temporal differences in toxicity, suggesting that storm water discharge from Paleta Creek may be the source of seasonal toxicity. Environ Toxicol Chem 2019;39:229–239. © 2019 SETACPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152638/1/etc4619_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152638/2/etc4619.pd
PLA Logistics and Sustainment: PLA Conference 2022
The US Army War College People’s Liberation Army Conference (PLA) Conference was held March 31 to April 2, 2022, at Carlisle Barracks, Pennsylvania.
The conference focused on PLA logistics and sustainment. As the PLA continues to build and modernize its combat forces, it is important to examine if the capabilities meant to support combat operations are also being developed.
Specific topics included: 1) China’s national-level logistics, including how China mobilizes national resources for the military and how it provides joint logistics support to the PLA Theater Commands; 2) the logistics capabilities of the different PLA services, especially the Army, Navy, and Air Forces; 3) PLA logistics in China’s remote regions, such as airpower projection in the Western Theater Command along the Indian border; and, 4) the PLA’s ability to sustain overseas operations at its base in Djibouti.
Despite notable potential shortfalls and points of friction, the PLA has successfully sustained counterpiracy maritime operations for many years and conducted noncombatant evacuation operations well-distant from China. It is increasingly able to move forces across the vast distances of China and conduct large training exercises. Far more must be known about PLA sustainment and logistics before the hard questions about PLA operational reach and endurance can be answered.https://press.armywarcollege.edu/monographs/1954/thumbnail.jp
Analytic calculation of nonadiabatic transition probabilities from monodromy of differential equations
The nonadiabatic transition probabilities in the two-level systems are
calculated analytically by using the monodromy matrix determining the global
feature of the underlying differential equation. We study the time-dependent
2x2 Hamiltonian with the tanh-type plus sech-type energy difference and with
constant off-diagonal elements as an example to show the efficiency of the
monodromy approach. The application of this method to multi-level systems is
also discussed.Comment: 13 pages, 2 figure
Studies of Vibrational Properties in Ga Stabilized d-Pu by Extended X-ray Absorption Fine Structure
Temperature dependent extended x-ray absorption fine structure (EXAFS)
spectra were measured for a 3.3 at% Ga stabilized Pu alloy over the range T= 20
- 300 K at both the Ga K-edge and the Pu L_III-edge. The temperature dependence
of the pair-distance distribution widths, \sigma(T) was accurately modeled
using a correlated-Debye model for the lattice vibrational properties,
suggesting Debye-like behavior in this material. We obtain pair- specific
correlated-Debye temperatures, \Theta_cD, of 110.7 +/- 1.7 K and 202.6 +/- 3.7
K, for the Pu-Pu and Ga-Pu pairs, respectively. These results represent the
first unambiguous determination of Ga-specific vibrational properties in PuGa
alloys, and indicate the Ga-Pu bonds are significantly stronger than the Pu-Pu
bonds. This effect has important implications for lattice stabilization
mechanisms in these alloys.Comment: 7 pages, 4 figures, Phys. Rev. B in pres
Arbitrary rotation and entanglement of flux SQUID qubits
We propose a new approach for the arbitrary rotation of a three-level SQUID
qubit and describe a new strategy for the creation of coherence transfer and
entangled states between two three-level SQUID qubits. The former is succeeded
by exploring the coupled-uncoupled states of the system when irradiated with
two microwave pulses, and the latter is succeeded by placing the SQUID qubits
into a microwave cavity and used adiabatic passage methods for their
manipulation.Comment: Accepted for publication in Phys. Rev.
A Call to Action: Taking the Untenable out of Women Professors’ Pregnancy, Postpartum, and Caregiving Demands
Despite becoming increasingly represented in academic departments, women scholars face a
critical lack of support as they navigate demands pertaining to pregnancy, motherhood, and child
caregiving. In addition, cultural norms surrounding how faculty and academic leaders discuss
and talk about tenure, promotion, and career success have created pressure for women who wish
to grow their family and care for their children, leading to questions about whether it is possible
for these women to have a family and an academic career. The current paper is a call to action
for academia to build structures that support women professors as they navigate the complexities
of pregnancy, the postpartum period, and the caregiving demands of their children. We
specifically call on those of us in I-O psychology, management, and related departments to lead
the way. In making this call, we first present the realistic, moral, and financial cases for why this
issue needs to be at the forefront of discussions surrounding success in the academy. We then
discuss how in the U.S. and elsewhere, an absence of policies supporting women places two
groups of academics—department heads (as the leaders of departments who have discretion
outside of formal policies to make work better for women) and other faculty members (as
potential allies both in the department and within our professional organizations)—in a critical
position to enact support and change. We conclude with our boldest call—to make a cultural
shift that shatters the assumption that having a family is not compatible with academic success.
Combined, we seek to launch a discussion that leads directly to necessary and overdue changes
in how women scholars are supported in academia
Visuospatial Functioning In The Primary Progressive Aphasias
Objectives: The aim of this study was to identify whether the three main primary progressive aphasia (PPA) variants would show differential profiles on measures of visuospatial cognition. We hypothesized that the logopenic variant would have the most difficulty across tasks requiring visuospatial and visual memory abilities. Methods: PPA patients (n = 156), diagnosed using current criteria, and controls were tested on a battery of tests tapping different aspects of visuospatial cognition. We compared the groups on an overall visuospatial factor; construction, immediate recall, delayed recall, and executive functioning composites; and on individual tests. Cross-sectional and longitudinal comparisons were made, adjusted for disease severity, age, and education. Results: The logopenic variant had significantly lower scores on the visuospatial factor and the most impaired scores on all composites. The nonfluent variant had significant difficulty on all visuospatial composites except the delayed recall, which differentiated them from the logopenic variant. In contrast, the semantic variants performed poorly only on delayed recall of visual information. The logopenic and nonfluent variants showed decline in figure copying performance over time, whereas in the semantic variant, this skill was remarkably preserved. Conclusions: This extensive examination of performance on visuospatial tasks in the PPA variants solidifies some previous findings, for example, delayed recall of visual stimuli adds value in differential diagnosis between logopenic variant PPA and nonfluent variant PPA variants, and illuminates the possibility of common mechanisms that underlie both linguistic and non-linguistic deficits in the variants. Furthermore, this is the first study that has investigated visuospatial functioning over time in the PPA variants
- …