1,687 research outputs found
Paper Session I-A - Is It SEP Yet?
This paper is a presentation of the results of recent studies indicating that solar electric propulsion can be implemented in a Discovery-class scenario to permit an affordable exploration of comets and asteroids in the very near future. Gallium arsenide solar array technology, the availability of space-qualified ion and plasma thrusters, and appropriate power conditioning equipment are cited as enabling factors for an exciting class of missions that can permit exploration of a number of asteroids and short-period comets, using the Delta launch vehicle, before the turn of the century. Launch requirements are about 993 kg to C$ = 10 km^/s^ for an assumed 50 to 75 kg complement of science instruments. An advantageous feature of electric propulsion is that the high installed power level, unnecessary for propulsion during rendezvous, enables high science data rates from most potential targets
Sampling bias in systems with structural heterogeneity and limited internal diffusion
Complex systems research is becomingly increasingly data-driven, particularly
in the social and biological domains. Many of the systems from which sample
data are collected feature structural heterogeneity at the mesoscopic scale
(i.e. communities) and limited inter-community diffusion. Here we show that the
interplay between these two features can yield a significant bias in the global
characteristics inferred from the data. We present a general framework to
quantify this bias, and derive an explicit corrective factor for a wide class
of systems. Applying our analysis to a recent high-profile survey of conflict
mortality in Iraq suggests a significant overestimate of deaths
Evidence of momentum dependent hybridization in Ce2Co0.8Si3.2
We studied the electronic structure of the Kondo lattice system Ce2Co0.8Si3.2
by angle-resolved photoemission spectroscopy (ARPES). The spectra obtained
below the coherence temperature consist of a Kondo resonance, its spin-orbit
partner and a number of dispersing bands. The quasiparticle weight related to
the Kondo peak depends strongly on Fermi vectors associated with bulk bands.
This indicates a highly anisotropic hybridization between conduction band and
4f electrons - V_{cf} in Ce2Co0.8Si3.2.Comment: 6 page
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Dynamic field test of a model levee founded on peaty organic soil using an eccentric mass shaker
A dynamic field test of a model levee was performed to study the behavior of very soft and compressible peaty organic soils that commonly underlie levees in the Sacramento / San Joaquin Delta in northern California. This first-of-its-kind test applied dynamic loads to the levee/peat system using a large eccentric mass shaker mounted on the levee crest. Loads from the shaker and the inertia of the levee section are transmitted to the peaty organic soils as base shear stresses, and rotational demands that manifest as normal pressures at the embankment/peat interface. We seek to characterize the transmission of seismic energy between the underlying soft peat and the overlying, comparatively stiff levee fills. A crucial step in the evaluation of the test data is calculation of the amplitude and phase of shaker forces. We compute the centrifugal force from discretely sampled proximity transducer data using a cosine sweep interpolation function
A framework for space-efficient string kernels
String kernels are typically used to compare genome-scale sequences whose
length makes alignment impractical, yet their computation is based on data
structures that are either space-inefficient, or incur large slowdowns. We show
that a number of exact string kernels, like the -mer kernel, the substrings
kernels, a number of length-weighted kernels, the minimal absent words kernel,
and kernels with Markovian corrections, can all be computed in time and
in bits of space in addition to the input, using just a
data structure on the Burrows-Wheeler transform of the
input strings, which takes time per element in its output. The same
bounds hold for a number of measures of compositional complexity based on
multiple value of , like the -mer profile and the -th order empirical
entropy, and for calibrating the value of using the data
Abordagem Multidisciplinar Em Hormonioterapia Neoadjuvante No Câncer De Mama: Uma Revisão
Breast cancer is the most common type of cancer and the leading cause of cancerrelated death among women worldwide. Hormone receptor-positive (HR+) tumors represent the most common form of this disease, with more than 70% of breast cancers expressing these receptors. Response and benefit to neoadjuvant chemotherapy (NCT) varies according to HR expression, with lower responses in luminal tumors as compared with hormone receptor-negative (HR-) and human epidermal growth factor receptor 2-positive (HER2+) tumors. Neoadjuvant endocrine therapy (NET) is an option for selected patients with HR+ locally advanced breast cancer. Neoadjuvant endocrine therapy has a favorable toxicity profile, and is associated with benefits such as having low cost and being more easily available even for cancer care professionals outside major urban areas or tertiary centers. These factors are particularly relevant, as 70% of breast cancer deaths occur in women from lowincome and middle-income countries. Additionally, NET is being increasingly explored, not simply to allow for less extensive surgery, but also as a scientific tool, with the use of biomarkers to predict outcomes in adjuvant trials and for the individual patient. This review details the current and most relevant evidence about NET for breast cancer as well as the future directions of this field. © 2016 by Thieme-Revinter Publicações Ltda, Rio de Janeiro, Brazil.381261562
High-Resolution Photoemission Study of MgB2
We have performed high-resolution photoemission spectroscopy on MgB2 and
observed opening of a superconducting gap with a narrow coherent peak. We found
that the superconducting gap is s-like with the gap value of 4.5 meV at 15 K.
The temperature dependence (15 - 40 K) of gap value follows well the BCS form,
suggesting that 2Delta/kBTc at T=0 is about 3. No pseudogap behavior is
observed in the normal state. The present results strongly suggest that MgB2 is
categorized into a phonon-mediated BCS superconductor in the weak-coupling
regime.Comment: 3 pages, 3 figures, accepted in Physical Review Letter
Manufacturing improvements project and its impact on financial outcome
In response to changes in the external conditions of the oil and gas processing industry, the requirements for the equipment of the oil refinery are forced to change, which calls for the implementation of investment projects. The article considers the data on the implementation of the project for the reconstruction of the primary oil refinery, shows its main technical and economic indicators, examines the direction of the project's impact on the financial performance of the enterprise as a whole
Hunting Billbug (Coleoptera: Curculionidae) Resistance Among Zoysiagrass ( Zoysia spp.) Cultivars
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