4,184 research outputs found
Space-time correlations in turbulent flow: A review
This paper reviews some of the principal uses, over almost seven decades, of
correlations, in both Eulerian and Lagrangian frames of reference, of
properties of turbulent flows at variable spatial locations and variable time
instants. Commonly called space--time correlations, they have been fundamental
to theories and models of turbulence as well as for the analyses of
experimental and direct numerical simulation turbulence data.Comment: 16 pages, 7 figure
Guidelines for the Provision of Garbage Reception Facilities at Ports Under MARPOL Annex V
This report offers guidelines for the provision of adequate
port reception facilities for vessel-generated garbage
under the requirements of Annex V of the International
Convention for the Prevention of Pollution From Ships, 1973 (MARPOL 73/78), Regulations for the Prevention of Pollution by Garbage from Ships. MARPOL Annex V prohibits at-sea disposal of plastic materials from vessels, and specifies the distance from shore at which other materials may be dumped. Annex V also requires the provision of port reception facilities for garbage, but it does not specify these facilities or how they are to be provided. Since the at-sea dumping restrictions apply to all vessels, the reception facility requirement applies to all ports, terminals, and marinas that serve vessels. These guidelines were prepared to assist port owners and operators in meeting their obligation to provide adequate reception facilities for garbage. The report synthesizes available information and draws upon experience from the first years ofimplementation of MARPOL Annex V. (PDF file contains 55 pages.
Recommended from our members
Use of genetic markers for the detection of off-types for DUS phenotypic traits in the inbreeding crop, barley
Detection of crop off-types is of interest for
multiple uses, including the assessment of uniformity
for new plant variety applications during distinctness,
uniformity and stability (DUS) testing for the awarding
of plant breeders’ rights (PBR). Here, we investigate
whether genetic markers, in this case Kompetitive
Allele-Specific PCR (KASP), can be used for the identification
off-types for phenotypes assessed for DUS in
the inbreeding cereal crop, barley (Hordeum vulgare).
To demonstrate proof of principle, KASP markers diagnostic
for phenotypic expression of nine DUS phenotypes,
and DNA from two barley varieties (‘Pelican’ and
‘Felicie’) carrying contrasting alleles at each marker
were used. We found that for the majority of markers,
it was possible to robustly call alleles down to template
DNA concentrations of 2 ng, but not ≤ 0.2 ng. When
used in mixtures of DNA consisting of ‘Felicie’ DNA
spiked with different concentrations of ‘Pelican’ DNA,
robust allele calling was possible in DNA mixtures
down to 18 ng:2 ng. Collectively, this demonstrates that
where diagnostic markers are available, molecular identification
of a single off-type for a given DUS trait
within a bulk of ten individuals should be possible. We
validated this assumption, with all of the diagnostic
genetic markers investigated found to robustly detect
DUS off-types at a frequency of 10% in DNA extracted
from tissue collected from pools of 10 individuals. Ultimately,
this work demonstrates that, where diagnostic
polymorphisms are known for DUS traits, KASP
markers should be able to robustly detect off-types or
cross-contamination within DNA samples from a diploid
inbred species down to 10%. While just two varieties
that contrasted for the eight DUS targeted were
investigated in this study, as the markers used are diagnostic
for their relevant phenotype (or a proportion of
the variation observed for that phenotype), in theory the
approach should be valid for any variety studied—
although the introduction of novel alleles via spontaneous
mutation or more exotic germplasm pools may
mean that marker sets would need to be periodically
added to or updated. However, we nevertheless demonstrate
the principle that, for a subset of DUS traits,
molecular markers can now be robustly used as a tool
towards determining all three components of the DUS
testing process in barley. These results are relevant for
the assessment of varietal uniformity by crop breeders,
crop testing authorities and germplasm maintenance, as
well as highlighting the potential use of bulk samples
rather than individual plant samples for assessment of
distinctness by molecular methods
Inventory of Lake Studies in Maine
Inventory of Lake Studies in Maine
By Charles F. Wallace, Jr. and James M. Strunk
State Planning Office, Water Resources Planning Division, July 1973.
Printed under Appropriation Number 4248.5 and financially assisted by planning grants from the United States Water Resources Council Title III funds.
Contents: Introduction / Investigating Agencies / Federal Agencies / State Agencies / Regional Planning Commissions and Economic Development Districts / Maine Colleges and Universities / Private / Other Private / Other / Appendiceshttps://digitalcommons.usm.maine.edu/me_collection/1134/thumbnail.jp
The Impact Of Management Security Control Consciousness On Security Control Activities: Implications For Compliance With The Sarbanes-Oxley Act
Using information system audit documentation from 60 clients of a Big 4 firm, we extend Kizirian (2004) by examining whether management security control consciousness (i.e., the “tone at the top”) influences (1) security control activities performed by the client, and (2) the auditor’s firm-wide (i.e., global) assessment of security control. Findings suggest that management control consciousness results in the employment of security controls. The auditor’s assessment of the strength of management control consciousness can also affect the auditor’s assessment of the client’s global security control. While our data pre-dates the Sarbanes-Oxley Act, our findings speak to the importance of assessing an organization's tone at the top, and thus, have implications for auditors working to certify a client’s compliance with the Sarbanes-Oxley Act
Investigation of Cracks Found in Helicopter Longerons
Four cracked longerons, containing a total of eight cracks, were provided for study. Cracked regions were cut from the longerons. Load was applied to open the cracks, enabling crack surface examination. Examination revealed that crack propagation was driven by fatigue loading in all eight cases. Fatigue crack initiation appears to have occurred on the top edge of the longerons near geometric changes that affect component bending stiffness. Additionally, metallurigical analysis has revealed a local depletion in alloying elements in the crack initiation regions that may be a contributing factor. Fatigue crack propagation appeared to be initially driven by opening-mode loading, but at a crack length of approximately 0.5 inches (12.7 mm), there is evidence of mixed-mode crack loading. For the longest cracks studied, shear-mode displacements destroyed crack-surface features of interest over significant portions of the crack surfaces
A fast scintillator Compton telescope for medium-energy gamma-ray astronomy
The field of medium-energy gamma-ray astronomy urgently needs a new mission to build on the success of the COMPTEL instrument on the Compton Gamma Ray Observatory. This mission must achieve sensitivity significantly greater than that of COMPTEL in order to advance the science of relativistic particle accelerators, nuclear astrophysics, and diffuse backgrounds, and bridge the gap between current and future hard X-ray missions and the high-energy Fermi mission. Such an increase in sensitivity can only come about via a dramatic decrease in the instrumental background. We are currently developing a concept for a low-background Compton telescope that employs modern scintillator technology to achieve this increase in sensitivity. Specifically, by employing LaBr3 scintillators for the calorimeter, one can take advantage of the unique speed and resolving power of this material to improve the instrument sensitivity while simultaneously enhancing its spectroscopic and imaging performance. Also, using deuterated organic scintillator in the scattering detector will reduce internal background from neutron capture. We present calibration results from a laboratory prototype of such an instrument, including time-of-flight, energy, and angular resolution, and compare them to simulation results using a detailed Monte Carlo model. We also describe the balloon payload we have built for a test flight of the instrument in the fall of 2010
A new low-background Compton telescope using LaBr3 scintillator
Gamma-ray astronomy in the MeV range suffers from weak fluxes from sources and high background in the nuclear energy range. The background comes primarily from neutron-induced gamma rays, with the neutrons being produced by cosmic-ray interactions in the Earth\u27s atmosphere, the spacecraft, and the instrument. Compton telescope designs often suppress this background by requiring coincidences in multiple detectors and a narrow time-of-flight (ToF) acceptance window. The COMPTEL experience on the Compton Gamma Ray Observatory shows that a 1.9-ns ToF resolution is insufficiently narrow to achieve the required low background count rate. Furthermore, neutron interactions in the detectors themselves generate an irreducible background. By employing LaBr3 scintillators for the calorimeter, one can take advantage of the unique speed and resolving power of the material to improve the instrument sensitivity and simultaneously enhance its spectroscopic performance and thus its imaging performance. We present a concept for a balloon- or space-borne Compton telescope that employs deuterated liquid in the scattering detector and LaBr3 as a calorimeter and estimate the improvement in sensitivity over past realizations of Compton telescopes. We show initial laboratory test results from a small prototype, including energy and timing resolution. Finally, we describe our plan to fly this prototype on a test balloon flight to directly validate our background predictions and guide the development of a full-scale instrument
- …