5,385 research outputs found
Library Materials For Children
Library materials for children cannot be considered alone, because the
term library has long implied more than a collection of books. It is fitting
that this topic follows papers discussing goals, facilities, staff, services,
and children themselves. A collection of materials is a means, not an end.
There is evidence that the isolation of materials from the concept
of service is not a new problem. Jesse Shera notes that the development
in the nineteenth century of the American public library began with collections
of books donated by successful businessmen and philanthropists
to uplift the minds of the young. When the Boston Public Library opened
its doors in 1854, however, those under eighteen were not admitted. The
mere fact that collections of materials for youth existed and had encouraged
library development did not mean that children were actually given
service. 1 This paper will attempt to raise questions about materials for
children in today's public library, their characteristics and availability; and
to discuss the relation of materials to other elements of library service.published or submitted for publicatio
Analysis of AVHRR, CZCS and historical in situ data off the Oregon Coast
The original scientific objectives of this grant were to: (1) characterize the seasonal cycles and interannual variability for phytoplankton concentrations and sea surface temperature (SST) in the California Current using satellite data; and (2) to explore the spatial and temporal relationship between these variables and surface wind forcing. An additional methodological objective was to develop statistical methods for forming mean fields, which minimize the effects of random data gaps and errors in the irregularly sampled CZCS (Coastal Zone Color Scanner) and AVHRR (Advanced Very High Resolution Radiometer) satellite data. A final task was to evaluate the level of uncertainty in the wind fields used for the statistical analysis. Funding in the first year included part of the cost of an image processing system to enable this and other projects to process and analyze satellite data. This report consists of summaries of the major projects carried out with all or partial support from this grant. The appendices include a list of papers and professional presentations supported by the grant, as well as reprints of the major papers and reports
High performance forward swept wing aircraft
A high performance aircraft capable of subsonic, transonic and supersonic speeds employs a forward swept wing planform and at least one first and second solution ejector located on the inboard section of the wing. A high degree of flow control on the inboard sections of the wing is achieved along with improved maneuverability and control of pitch, roll and yaw. Lift loss is delayed to higher angles of attack than in conventional aircraft. In one embodiment the ejectors may be advantageously positioned spanwise on the wing while the ductwork is kept to a minimum
The Criminal Justice Act - 1964 To 1976
Colloquium: The Federal Judiciary: Essays from the Benc
The Criminal Justice Act - 1964 To 1976
Colloquium: The Federal Judiciary: Essays from the Benc
Application of image analysis in microecophysiology research : methodology development.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.Rehabilitation of landfill sites is important for successful land utilization. Revegetation is
one key element of the process since it can overcome aesthetic problems. The inimical
challenges of landfill leachate and gas are largely responsible for the difficulties associated
with the revegetation of completed sites. Many components of landfill leachate can be
catabolized by microbial associations thereby reducing their impacts on the environment.
The importance of research on interactions between pollutants, microorganisms and soil
is its applicability in environmental risk assessment and impact studies of organic
pollutants which enter the soil either accidentally or intentionally.
The application of image analysis with microscopy techniques to landfill soil-pollution
interactions provides a means to study surface microbiology directly and to investigate
microbial cells under highly controlled conditions. This research focused on the
development of a method to study the real time processes of attachment, establishment,
growth and division of microbial cells/associations in site covering soils. Image analysis
provides a powerful tool for differential quantification of microbial number, identification
of morphotypes and their respective responses to microenvironment changes. This
minimal disturbance technique of examining visually complex images utilizes the spatial
distributions and metabolic sensitivities of microbial species. It was, therefore, used to
examine hexanoic acid catabolizing species, both free-living and in a biofilm, with respect
to obviating the threat of hexanoic acid to reclamation strategies.
The three sources of inoculum (soil cover, soil from the landfill base liner and municipal
refuse) were compared for their ability to provide associations which catabolized the
substrate rapidly. During the enrichment programme the inocula were challenged with different concentrations of hexanoic acid, a common landfill intermediate. From the rates
at which the substrate was catabolized conclusions were drawn on which concentration
of hexanoate facilitated the fastest enrichment. The results of initial batch culture
enrichments confirmed that the soil used contained microbial associations capable of
catabolizing hexanoic acid at concentrations < 50mM, a key leachate component.
Exposing the landfill top soil microorganisms to a progressive increase in hexanoic acid
concentration ensured that catabolic populations developed which, in situ, should reduce
the phytotoxic threat to plants subsequently grown on the landfill cover.
The analysis of surface colonization was simplified by examining the initial growth on
newly-exposed surfaces. The microbial associations generated complex images which
were visually difficult to quantify. Nevertheless, the dimensional and morphological
exclusions which were incorporated in the image analysis software permitted the
quantification of selected components of the associations although morphology alone was
inadequate to confirm identification.
The effects of increasing the dilution rate and substrate concentration on the growth of
surface-attached associations in Continuous Culture Microscopy Units (CCMUs) were
examined. Of the five dilution rates examined the most extensive biofilm development
(9.88 jum2) during the selected time period (72h) resulted at a dilution rate of 0.5h' (at
10mM hexanoic acid). The highest growth (608 microorganisms.field"1) was recorded in
the presence of 50mM hexanoic acid (D = 0.5h"1). To ensure that the different
morphotypes of the associations were able to multiply under the defined conditions a
detailed investigation of the component morphotypes was made. Numerically, after 60h
of open culture cultivation in the presence of 50mM hexanoic acid, rods were the
predominant bacterial morphotypes (43.74 field'1) in the biofilms. Both rods and cocci were distributed throughout the CCMUs whereas the less numerous fungal hyphae (0.25
field'1) were concentrated near the effluent port.
The specific growth rates of the surface-attached associations and the component
morphotypes were determined by area (//m2) colonized and number of
microorganisms.field"' and compared to aerobic planktonic landfill associations. From area
determinations ( > 0.16 h'1) and the number of microorganisms.field"1 10mM hexanoic
acid was found to support the highest specific growth rate ( > 0.05 h"1) of the surfaceattached
association isolated from municipal refuse. With optical density determinations,
the highest specific growth rate (0.01 h'1) was recorded with 25mM hexanoic acid. The
surface-attached microbial associations component species determinations by area and
number showed that the hyphae had the highest specific growth rate ( > 0.11 h"1). The
surface-attached microbial association specific growth rate determinations from the
discriminated phase (0.023 h'1), area colonized (0.023 h"1) and number of microorganisms
(0.027 h"1) calculated from the results of the component species rather than the
association should give more accurate results.
The specific growth rate obtained differed depending on the method of determination. Any
one of these may be the "correct" answer under the cultivation conditions. Depending on
the state (thickness) of the association (free-living, monolayer or thick biofilm) the different
monitoring methods may be employed to determine the growth. As a consequence of the
results of this study, the kinetics of microbial colonization of surfaces in situ may be
subjected to the same degree of mathematical analysis as the kinetics of homogeneous
cultures. This type of analysis is needed if quantitative studies of microbial growth are to
be extended to surfaces in various natural and artificial environments
Modulation instability, Akhmediev Breathers and continuous wave supercontinuum generation
Numerical simulations of the onset phase of continuous wave supercontinuum
generation from modulation instability show that the structure of the field as
it develops can be interpreted in terms of the properties of Akhmediev
Breathers. Numerical and analytical results are compared with experimental
measurements of spectral broadening in photonic crystal fiber using nanosecond
pulsesComment: 22 pages, 6 figure
Fueling climate (in)action:How organizations engage in hegemonization to avoid transformational action on climate change
This study examines how organizations avoid the urgent need for transformational action on climate change by engaging in a hegemonization process. To show how this unfolds, we draw from Laclau and Mouffe’s discourse theory, focusing on the case of BP and its engagement with the climate change debate from 1990 to 2015. Our study takes a longitudinal approach to illustrate how BP defended its core business of producing and selling fossil fuel products by enacting three sequential hegemonization strategies. These included: adopting new signifiers; building ‘win-win’ relationships; and adapting nodal points. In doing so, we demonstrate how hegemonic construction enables organizations to both incorporate and evade various types of stakeholder critique, which, we argue, reproduces business-as-usual. Our study contributes to organization studies literature on hegemony by highlighting how the construction of hegemony operates accumulatively over an extended period of time. We also contribute more broadly to conversations around political contests and the natural environment by illustrating how the lack of effective climate responses is shaped by temporal dynamics
On the modulation instability development in optical fiber systems
Extensive numerical simulations were performed to investigate all stages of
modulation instability development from the initial pulse of pico-second
duration in photonic crystal fiber: quasi-solitons and dispersive waves
formation, their interaction stage and the further propagation. Comparison
between 4 different NLS-like systems was made: the classical NLS equation, NLS
system plus higher dispersion terms, NLS plus higher dispersion and
self-steepening and also fully generalized NLS equation with Raman scattering
taken into account. For the latter case a mechanism of energy transfer from
smaller quasi-solitons to the bigger ones is proposed to explain the dramatical
increase of rogue waves appearance frequency in comparison to the systems when
the Raman scattering is not taken into account.Comment: 9 pages, 54 figure
Influence of turbulence on the dynamo threshold
We use direct and stochastic numerical simulations of the magnetohydrodynamic
equations to explore the influence of turbulence on the dynamo threshold. In
the spirit of the Kraichnan-Kazantsev model, we model the turbulence by a
noise, with given amplitude, injection scale and correlation time. The addition
of a stochastic noise to the mean velocity significantly alters the dynamo
threshold. When the noise is at small (resp. large) scale, the dynamo threshold
is decreased (resp. increased). For a large scale noise, a finite correlation
time reinforces this effect
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