179 research outputs found
A Method for siting and prioritizing the removal of derelict vessels in Florida Coastal Waters: test applications in the Florida Keys
Increased boating activities and new waterfront developments have contributed an
estimated 3,000 dismantled, abandoned, junked, wrecked, derelict vessels to Florida
coastal waters. This report outlines a method of siting and prioritizing derelict vessel
removal using the Florida Keys as a test area. The data base was information on 240
vessels, obtained from Florida Marine Patrol files. Vessel location was plotted on 1:250,000
regional and 1:5,000 and 1:12,000 site maps. Type of vessel, length, hull material, engine,
fuel tanks, overall condition, afloat and submerged characteristics, and accessibility, were
used to derive parametric site indices of removal priority and removal difficulty.
Results indicate 59 top priority cases which should be the focus of immediate clean
up efforts in the Florida Keys. Half of these cases are rated low to moderate in removal
difficulty; the remainder are difficult to remove. Removal difficulty is a surrogate for
removal cost: low difficulty -low cost, high difficulty - high cost. The rating scheme offers
coastal planners options of focusing removal operations either on (1) specific areas with
clusters of high priority derelict vessels or on (2) selected targeted derelicts at various,
specific locations. (PDF has 59 pages.
Personal traits, knowledge, and skills considered in reference to employment in Terre Haute industries
Not Available.W.C. GarretsonNot ListedNot ListedMaster of ScienceDepartment Not ListedCunningham Memorial library, Terre Haute, Indiana State University.isua-thesis-1932-garretsonMastersTitle from document title page. Document formatted into pages: contains 120p. : ill. Includes appendix
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A Unit Manufacturing Process Characterization Methodology and Supporting Terminology for Sustainable Manufacturing Assessment
Manufacturing industry drives economic activity and growth around the world, but manufacturing activities consume large amounts of material, energy, and labor resources. Therefore, the impacts of manufacturing need to be accounted for and reduced. Direct benefits of manufacturing are products and income, which, in turn, influence the lives of people in the local community and the consumers purchasing the manufactured products. The design process for products and requisite manufacturing facilities should incorporate environmental and social criteria in addition to economic criteria to more comprehensively assess sustainability performance. Sustainability assessments for manufactured products and manufacturing facilities can be carried out by assessing the incremental elements of manufacturing industry, which are unit manufacturing processes (UMPs).
A challenge in the research area is that current methods for UMP assessment are ad hoc and the methods do not incorporate the system as a whole. The purpose of this research is to enable sustainable manufacturing decision making by 1) unifying an assessment methodology for UMPs, 2) developing an information modeling framework for characterizing UMPs and workpieces, and 3) demonstrating UMP composability (connectivity) modeling for use in sustainability assessments. The methodology is developed through literature review, and unifies 23 different UMP manufacturing assessment methods by analyzing each for overlapping and unique steps in the approaches. Thus, a nine-step assessment methodology emerged, which has multiple applications in industry, including process and facility assessment and improvement.
A next step for MPF modeling is to link UMP models by modeling the workpiece state, but supporting tools were need to identifying how to correctly model the interactions between the UMP and the workpiece. The information modeling framework developed herein provides the theoretical background for how UMP models interact by linking the function of the UMP to the effect on the workpiece and by identifying the calculation variables necessary to assess UMPs. The information modeling framework developed for composing UMP models is demonstrated through the energy analysis of a metal component. The component is manufactured by recrystallization annealing, reducing (milling), through hardening, and recovery annealing (tempering). Models are composed (connected) by utilizing knowledge of how UMPs impart transformation to the workpiece and the information embedded in the workpiece that is transported to subsequent UMPs. Workpiece information includes the geometry and properties of the current state and future states. Previous work reported in literature has focused on geometry modeling (e.g. CAD, CAM), while this work focuses on property modeling. This research develops an overarching detailed approach to manufacturing sustainability assessments through in-depth analysis of UMPs. The result of using this UMP approach will provide guidance toward a more sustainable future
Electromagnetic Origin of the CMB Anisotropy in String Cosmology
In the inflationary scenarios suggested by string theory, the vacuum
fluctuations of the electromagnetic field can be amplified by the
time-evolution of the dilaton background, and can grow large enough to explain
both the origin of the cosmic magnetic fields and of the observed CMB
anisotropy. The normalization of the perturbation spectrum is fixed, and
implies a relation between the perturbation amplitude at the COBE scale and the
spectral index . Working within a generic two-parameter family of
backgrounds, a large scale anisotropy is found to
correspond to a spectral index in the range .Comment: 11 pages, LATE
The Cosmic Microwave Background and Helical Magnetic Fields: the tensor mode
We study the effect of a possible helicity component of a primordial magnetic
field on the tensor part of the cosmic microwave background temperature
anisotropies and polarization. We give analytical approximations for the tensor
contributions induced by helicity, discussing their amplitude and spectral
index in dependence of the power spectrum of the primordial magnetic field. We
find that an helical magnetic field creates a parity odd component of gravity
waves inducing parity odd polarization signals. However, only if the magnetic
field is close to scale invariant and if its helical part is close to maximal,
the effect is sufficiently large to be observable. We also discuss the
implications of causality on the magnetic field spectrum.Comment: We have corrected a normalisation error which was pointed out to us
by Antony Lewis. It enhances our limits on the magnetic fields by
(2\pi)^{3/4} ~
Grounding Bohmian Mechanics in Weak Values and Bayesianism
Bohmian mechanics (BM) is a popular interpretation of quantum mechanics in
which particles have real positions. The velocity of a point x in configuration
space is defined as the standard probability current j(x) divided by the
probability density P(x). However, this ``standard'' j is in fact only one of
infinitely many that transform correctly and satisfy \dot P + \del . j=0. In
this article I show that there is a unique j that can be determined
experimentally as a weak value using techniques that would make sense to a
classical physicist. Moreover, this operationally defined j equals the standard
j, so, assuming \dot x = j/P, the possible Bohmian paths can also be determined
experimentally from a large enough ensemble. Furthermore, this approach to
deriving BM singles out x as the hidden variable, because (for example) the
operationally defined momentum current is in general incompatible with the
evolution of the momentum distribution. Finally I discuss how, in this setting,
the usual quantum probabilities can be derived from a Bayesian standpoint, via
the principle of indifference.Comment: 11 page
Speculations on Primordial Magnetic Helicity
We speculate that above or just below the electroweak phase transition
magnetic fields are generated which have a net helicity (otherwise said, a
Chern-Simons term) of order of magnitude , where is the
baryon or lepton number today. (To be more precise requires much more knowledge
of B,L-generating mechanisms than we currently have.) Electromagnetic helicity
generation is associated (indirectly) with the generation of electroweak
Chern-Simons number through B+L anomalies. This helicity, which in the early
universe is some 30 orders of magnitude greater than what would be expected
from fluctuations alone in the absence of B+L violation, should be reasonably
well-conserved through the evolution of the universe to around the times of
matter dominance and decoupling, because the early universe is an excellent
conductor. Possible consequences include early structure formation; macroscopic
manifestations of CP violation in the cosmic magnetic field (measurable at
least in principle, if not in practice); and an inverse-cascade dynamo
mechanism in which magnetic fields and helicity are unstable to transfer to
larger and larger spatial scales. We give a quasi-linear treatment of the
general-relativistic MHD inverse cascade instability, finding substantial
growth for helicity of the assumed magnitude out to scales , where is roughly the B+L to photon ratio and
is the magnetic correlation length. We also elaborate further on an
earlier proposal of the author for generation of magnetic fields above the EW
phase transition.Comment: Latex, 23 page
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Disorder-specific functional abnormalities during sustained attention in youth with Attention Deficit Hyperactivity Disorder (ADHD) and with Autism
Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are often comorbid and share behavioural-cognitive abnormalities in sustained attention. A key question is whether this shared cognitive phenotype is based on common or different underlying pathophysiologies. To elucidate this question, we compared 20 boys with ADHD to 20 age and IQ matched ASD and 20 healthy boys using functional magnetic resonance imaging (fMRI) during a parametrically modulated vigilance task with a progressively increasing load of sustained attention. ADHD and ASD boys had significantly reduced activation relative to controls in bilateral striato–thalamic regions, left dorsolateral prefrontal cortex (DLPFC) and superior parietal cortex. Both groups also displayed significantly increased precuneus activation relative to controls. Precuneus was negatively correlated with the DLPFC activation, and progressively more deactivated with increasing attention load in controls, but not patients, suggesting problems with deactivation of a task-related default mode network in both disorders. However, left DLPFC underactivation was significantly more pronounced in ADHD relative to ASD boys, which furthermore was associated with sustained performance measures that were only impaired in ADHD patients. ASD boys, on the other hand, had disorder-specific enhanced cerebellar activation relative to both ADHD and control boys, presumably reflecting compensation. The findings show that ADHD and ASD boys have both shared and disorder-specific abnormalities in brain function during sustained attention. Shared deficits were in fronto–striato–parietal activation and default mode suppression. Differences were a more severe DLPFC dysfunction in ADHD and a disorder-specific fronto–striato–cerebellar dysregulation in ASD
Large-scale magnetic fields from inflation in dilaton electromagnetism
The generation of large-scale magnetic fields is studied in dilaton
electromagnetism in inflationary cosmology, taking into account the dilaton's
evolution throughout inflation and reheating until it is stabilized with
possible entropy production. It is shown that large-scale magnetic fields with
observationally interesting strength at the present time could be generated if
the conformal invariance of the Maxwell theory is broken through the coupling
between the dilaton and electromagnetic fields in such a way that the resultant
quantum fluctuations in the magnetic field has a nearly scale-invariant
spectrum. If this condition is met, the amplitude of the generated magnetic
field could be sufficiently large even in the case huge amount of entropy is
produced with the dilution factor as the dilaton decays.Comment: 28 pages, 5 figures, the version accepted for publication in Phys.
Rev. D; some references are adde
Primordial magnetic fields from inflation?
The hot plasma above the electroweak scale contains (hyper) charged scalar
particles which are coupled to Abelian gauge fields. Scalars may interact with
gravity in a non-conformally invariant way and thus their fluctuations can be
amplified during inflation. These fluctuations lead to creation of electric
currents and produce inhomogeneous distribution of charge density, resulting in
the generation of cosmological magnetic fields. We address the question whether
these fields can be coherent at large scales so that they may seed the galactic
magnetic fields. Depending upon the mass of the charged scalar and upon various
cosmological (critical fraction of energy density in matter, Hubble constant)
and particle physics parameters we found that the magnetic fields generated in
this way are much larger than vacuum fluctuations. However, their amplitude on
cosmological distances is found to be too small for seeding the galactic
magnetic fields.Comment: 32 pages in RevTex styl
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