684 research outputs found
Securitisation and currency hedging under Islamic Shafi law, part 1
This, the first part of a two-part article, examines key features of asset-backed securitisation and currency hedging under Islamic Shafi law. Reviews basic principles of Shafi law, and the Musharaka structures of its profit-sharing agreements, the use of Ijarah structures in securitisation, agency agreements using the Wakalah structure, purchase and sale transactions under the Salam structure, and asset financing through Murabahah structures
A Study of Future Communications Concepts and Technologies for the National Airspace System - Part II
The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is investigating current and anticipated wireless communications concepts and technologies that the National Airspace System (NAS) may need in the next 50 years. NASA has awarded three NASA Research Announcements (NAR) studies with the objective to determine the most promising candidate technologies for air-to-air and air-to-ground data exchange and analyze their suitability in a post-NextGen NAS environment. This paper will present progress made in the studies and describe the communications challenges and opportunities that have been identified during the studies' first year
A Study of Future Communications Concepts and Technologies for the National Airspace System - Part IV
The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is investigating current and anticipated wireless communications concepts and technologies that the National Airspace System (NAS) may need in the next 50 years. NASA has awarded three NASA Research Announcements (NAR) studies with the objective to determine the most promising candidate technologies for air-to-air and air-to-ground data exchange and analyze their suitability in a post-NextGen NAS environment. This paper will present the final results describing the communications challenges and opportunities that have been identified as part of the study
A Study of Future Communications Concepts and Technologies for the National Airspace System-Part III
The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is investigating current and anticipated wireless communications concepts and technologies that the National Airspace System (NAS) may need in the next 50 years. NASA has awarded three NASA Research Announcements (NAR) studies with the objective to determine the most promising candidate technologies for air-to-air and air-to-ground data exchange and analyze their suitability in a post-NextGen NAS environment. This paper will present progress made in the studies and describe the communications challenges and opportunities that have been identified as part of the study. NASA's NextGen Concepts and Technology Development (CTD) Project integrates solutions for a safe, efficient and high-capacity airspace system through joint research efforts and partnerships with other government agencies. The CTD Project is one of two within NASA's Airspace Systems Program and is managed by the NASA Ames Research Center. Research within the CTD Project is in support the 2011 NASA Strategic Plan Sub-Goal 4.1: Develop innovative solutions and advanced technologies, through a balanced research portfolio, to improve current and future air transportation. The focus of CTD is on developing capabilities in traffic flow management, dynamic airspace configuration, separation assurance, super density operations and airport surface operations. Important to its research is the development of human/automation information requirements and decisionmaking guidelines for human-human and human-machine airportal decision-making. Airborne separation, oceanic intrail climb/descent and interval management applications depend on location and intent information of surrounding aircraft. ADS-B has been proposed to provide the information exchange, but other candidates such as satellite-based receivers, broadband or airborne internet, and cellular communications are possible candidate's
The curious case of J113924.74+164144.0: a possible new group of galaxies at z = 0.0693
J113924.74+164144.0 is an interesting galaxy at z = 0.0693, i.e. D_L ~ 305
Mpc, with tidal-tail-like extended optical features on both sides. There are
two neighbouring galaxies, a spiral galaxy J113922.85+164136.3 which has a
strikingly similar 'tidal' morphology, and a faint galaxy J113923.58+164129.9.
We report HI 21 cm observations of this field to search for signatures of
possible interaction. Narrow HI emission is detected from J113924.74+164144.0,
but J113922.85+164136.3 shows no detectable emission. The total HI mass
detected in J113924.74+164144.0 is 7.7 x 10^9 M_solar. The HI emission from the
galaxy is found to be extended and significantly offset from the optical
position of the galaxy. We interpret this as signature of possible interaction
with the neighbouring spiral galaxy. There is also a possible detection of HI
emission from another nearby galaxy J113952.31+164531.8 at z = 0.0680 at a
projected distance of 600 kpc, and with a total HI mass of 5.3 x 10^9 M_solar,
suggesting that all these galaxies form a loose group at z ~ 0.069.Comment: 5 pages, 1 table, 6 figures. Accepted for publication in MNRAS
Letters. The definitive version will be available at
http://www.blackwell-synergy.com
Effect of dark matter halo substructures on galaxy rotation curves
The effect of halo substructures on galaxy rotation curves is investigated in
this paper using a simple model of dark matter clustering. A dark matter halo
density profile is developed based only on the scale free nature of clustering
that leads to a statistically self-similar distribution of the substructures at
galactic scale. Semi-analytical method is used to derive rotation curves for
such a clumpy dark matter density profile. It is found that the halo
substructures significantly affect the galaxy velocity field. Based on the
fractal geometry of the halo, this self-consistent model predicts an NFW-like
rotation curve and a scale free power spectrum of the rotation velocity
fluctuations.Comment: 6 pages, 3 figures. Accepted for publication in ApJ. The definitive
version will be available at http://iopscience.iop.org
NASAwide electronic publishing system: Prototype STI electronic document distribution, stage-4 evaluation report
This evaluation report contains an introduction, seven chapters, and five appendices. The Introduction describes the purpose, conceptual frame work, functional description, and technical report server of the STI Electronic Document Distribution (EDD) project. Chapter 1 documents the results of the prototype STI EDD in actual operation. Chapter 2 documents each NASA center's post processing publication processes. Chapter 3 documents each center's STI software, hardware, and communications configurations. Chapter 7 documents STI EDD policy, practices, and procedures. The appendices, which arc contained in Part 2 of this document, consist of (1) STI EDD Project Plan, (2) Team members, (3) Phasing Schedules, (4) Accessing On-line Reports, and (5) Creating an HTML File and Setting Up an xTRS. In summary, Stage 4 of the NASAwide Electronic Publishing System is the final phase of its implementation through the prototyping and gradual integration of each NASA center's electronic printing systems, desktop publishing systems, and technical report servers to be able to provide to NASA's engineers, researchers, scientists, and external users the widest practicable and appropriate dissemination of information concerning its activities and the result thereof to their work stations
PINGS: the PPAK IFS Nearby Galaxies Survey
We present the PPAK Integral Field Spectroscopy (IFS) Nearby Galaxies Survey:
PINGS, a 2-dimensional spectroscopic mosaicking of 17 nearby disk galaxies in
the optical wavelength range. This project represents the first attempt to
obtain continuous coverage spectra of the whole surface of a galaxy in the
nearby universe. The final data set comprises more than 50000 individual
spectra, covering in total an observed area of nearly 80 arcmin^2. In this
paper we describe the main astrophysical issues to be addressed by the PINGS
project, we present the galaxy sample and explain the observing strategy, the
data reduction process and all uncertainties involved. Additionally, we give
some scientific highlights extracted from the first analysis of the PINGS
sample.Comment: Accepted for publication in MNRAS, 26 pages, 14 figures (some in low
resolution), 3 table
Does oral sodium bicarbonate therapy improve function and quality of life in older patients with chronic kidney disease and low-grade acidosis (the BiCARB trial)? Study protocol for a randomized controlled trial
Date of acceptance: 01/07/2015 © 2015 Witham et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Acknowledgements UK NIHR HTA grant 10/71/01. We acknowledge the financial support of NHS Research Scotland in conducting this trial.Peer reviewedPublisher PD
Nonthermal Emission from Star-Forming Galaxies
The detections of high-energy gamma-ray emission from the nearby starburst
galaxies M82 & NGC253, and other local group galaxies, broaden our knowledge of
star-driven nonthermal processes and phenomena in non-AGN star-forming
galaxies. We review basic aspects of the related processes and their modeling
in starburst galaxies. Since these processes involve both energetic electrons
and protons accelerated by SN shocks, their respective radiative yields can be
used to explore the SN-particle-radiation connection. Specifically, the
relation between SN activity, energetic particles, and their radiative yields,
is assessed through respective measures of the particle energy density in
several star-forming galaxies. The deduced energy densities range from O(0.1)
eV/cm^3 in very quiet environments to O(100) eV/cm^3 in regions with very high
star-formation rates.Comment: 17 pages, 5 figures, to be published in Astrophysics and Space
Science Proceeding
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