13,297 research outputs found
Classical Liquids in Fractal Dimension
We introduce fractal liquids by generalizing classical liquids of integer
dimensions to a fractal dimension . The particles composing
the liquid are fractal objects and their configuration space is also fractal,
with the same non-integer dimension. Realizations of our generic model system
include microphase separated binary liquids in porous media, and highly
branched liquid droplets confined to a fractal polymer backbone in a gel. Here
we study the thermodynamics and pair correlations of fractal liquids by
computer simulation and semi-analytical statistical mechanics. Our results are
based on a model where fractal hard spheres move on a near-critical percolating
lattice cluster. The predictions of the fractal Percus-Yevick liquid integral
equation compare well with our simulation results.Comment: Changed titl
Data analysis of continuous gravitational wave: Fourier transform-I
We present the Fourier Transform of a continuous gravitational wave. We have
analysed the data set for one day observation time and our analysis is
applicable for arbitrary location of detector and source. We have taken into
account the effects arising due to rotational as well as orbital motions of the
earth.Comment: Accepted in MNRAS, 22 pages, 9 figure
Classical Robustness of Quantum Unravellings
We introduce three measures which quantify the degree to which quantum
systems possess the robustness exhibited by classical systems when subjected to
continuous observation. Using these we show that for a fixed environmental
interaction the level of robustness depends on the measurement strategy, or
unravelling, and that no single strategy is maximally robust in all ways.Comment: 8 Pages, 2 figures, Version 2. Minor changes to wording for
clarification and some references added. Accepted for publication in
Europhysics Letter
The New Eclipsing Cataclysmic Variable SDSS 154453+2553
The cataclysmic variable SDSS154453+2553 was recently identified in the Sloan
Digital Sky Survey. We obtained spectra and photometry at the MDM Observatory,
which revealed an eclipse with a 6.03 hour period. The H{\alpha} emission line
exhibits a strong rotational disturbance during eclipse, indicating that it
arises in an accretion disk. A contribution from an M-type companion is also
observed. Time-series photometry during eclipse gives an ephemeris of
2454878.0062(15) + 0.251282(2)E. We present spectroscopy through the orbit and
eclipse photometry. Our analysis of the secondary star indicates a distance of
800 {\pm} 180 pc.Comment: 6 pages, 3 figures, Accepted for publication in PAS
The challenge of moral difference : a theoretical investigation of encounters with a client\u27s capacity for violence
Clinical social workers face an ethical imperative to work with a range of clients, some of whom will undoubtedly espouse views and confess to violent behavior that will differ, sometimes profoundly, with the worker\u27s own personal moral compass and the values of the social work profession. How are clinical social workers to navigate the potential impasses that arise from such encounters? This theoretical thesis explores the dilemma of engaging with a client whose morality is experienced by the worker as untenable. It draws on two bodies of theory, moral anthropology and relational psychoanalysis—both of which emphasize contingency, circumstance, and the role of social phenomena in shaping an individual\u27s subjectivity and identities. These bodies of theory are applied to two cases set in apartheid and post-apartheid South Africa (Gobodo-Madikizela, 2003; Straker, 2007a). While these cases focus on the extremes of human behavior in a particular historical and cultural locale, they also offer a paradigm of what it means to face a client whose morality profoundly differs from one\u27s own and how one might overcome the impasse precluding empathy for the client\u27s subjectivity and recognition of his or her human dignity
Analysis of the Import, Export, and Bioavailability of Nitrogen and Phosphorus Within Pineview Reservoir
This study was conducted to provide new and useful data about Pineview Reservoir and its watershed, produce water and phosphorus (P) budgets for Pineview Reservoir, test the validity of conclusions made in the Pineview Reservoir Total Maximum Daily Loading (TMDL) document, and create estimates of nitrogen (N) loading to the reservoir from both surface and ground water sources. The production of the water and P budgets, as well as the N loading estimates, was accomplished by measuring flow, nitrate, ammonium, total phosphorus (TP), and soluble reactive phosphorus (SRP) that was entering and exiting the reservoir through surface water sources and the reservoir outlet over a period of approximately 2 years (2008 to 2010). Estimates of ground water contributions to the reservoir were also made using ground water P and N concentration data from a parallel study and ground water flow estimates from the literature. In order to test the validity of claims made in the TMDL, internal reservoir parameters such as temperature, dissolved oxygen, TP, orthophosphorus (OP), nitrate, ammonium and dissolved iron (Fe) were measured at the surface, thermocline, and hypolimnion of five sampling locations within the reservoir over the same sampling period. Chlorophyll A was also measured near the surface of the sites during each sampling event. Contrary to the conclusions made by the TMDL it was found that the internal cycling of nutrients, especially P, is occurring in Pineview Reservoir and that annually observed phytoplankton blooms can be attributed to the release of benthic nutrients. It was also found that there is a large store of sediment P that is currently or potentially could be made available for transfer into the water column. It was estimated that 14,800 kg of P was exported from the reservoir over the one-year sample period of 4/15/2009 to 4/14/2010. This large P release is due to the practice of exporting P rich hypolimnetic water throughout the summer irrigation season. It was shown that more P could be exported if outflows were increased during this period. P budgets indicated that P may not currently be building up within Pineview Reservoir, but given the limited amount of ground water data available for the Reservoir’s watershed, further ground water flow and nutrient data are necessary to substantiate this claim. This study has helped to provide a clearer picture of the trophic status and internal P cycles of Pineview Reservoir. It has also helped to answer questions about the reservoir that have been overlooked in previous studies, such as the magnitude of internal P loading and the importance of Spring Creek and Geertsen Creek in the reservoir’s water budget. This and other information gathered during this study could prove to be a useful benchmark for measuring the effectiveness of future efforts to improve water quality in the reservoir
The NASA atomic oxygen effects test program
The NASA Atomic Oxygen Effects Test Program was established to compare the low earth orbital simulation characteristics of existing atomic oxygen test facilities and utilize the collective data from a multitude of simulation facilities to promote understanding of mechanisms and erosion yield dependence upon energy, flux, metastables, charge, and environmental species. Four materials chosen for this evaluation include Kapton HN polyimide, FEP Teflon, polyethylene, and graphite single crystals. The conditions and results of atomic oxygen exposure of these materials is reported by the participating organizations and then assembled to identify degrees of dependency of erosion yields that may not be observable from any single atomic oxygen low earth orbital simulation facility. To date, the program includes 30 test facilities. Characteristics of the participating test facilities and results to date are reported
Quantifying Variation in High-Quality Footwear Replicate Impressions
A footwear impression collected at a crime scene can provide information about the shoe that created it, yielding investigative leads, excluding persons-of-interest, and linking evidence between cases. The analysis of footwear evidence often requires the preparation of test impressions from known exemplar shoes created under controlled laboratory conditions for comparison to questioned impressions. The goal of these comparisons is to evaluate the degree of similarities and differences between the questioned impression and potential sources.
Given that this comparison leads to an assessment of the nature and degree of agreement between questioned and known impressions, it is important to characterize the variation that may exist between replicate test impressions created in the laboratory. This study aimed to evaluate the variation that exists within and between test impressions prepared using a static benchtop and a dynamic walking method, as well as explore the potential influence of the wearer’s foot size when using the walking method.
To examine this variation, twenty-three participants were recruited to prepare test impressions of two different shoe makes and models in four different manufacturer’s sizes. Five replicate benchtop impressions per make/model/size and three replicate walking impressions per participant/make/model/size were created, resulting in more than 500 test impressions. A total of 150 quality control copies were blindly mixed into the larger dataset, increasing the total to almost 700 test impressions. Reproducible and reliable ground control points, such as the edge of a tread element, defined points of interest on impressions, and the distance between pairs of points was computed as a function of method and foot/shoe size match or mismatch.
Physical size differences between measurements from benchtop impressions versus walking impressions of the same shoe were computed, and the largest physical size difference measured was 4.18 mm, which is concerning since the smallest reported physical size difference between manufacturer’s half-sizes is 4.20 mm [1]. Bland-Altman analyses were performed to determine estimates of agreement of measurements and possible bias between methods of impression creation. The methods revealed a systematic bias in that benchtop impressions were always longer and narrower than walking impressions. Additionally, the largest upper bound on the limit of agreement was 4.75 mm, indicating that differences in measurements between benchtop and walking impressions could be as large as 4.75 mm. Analysis of covariance was used to test for a numerical significance between each method used to create test impressions, while controlling for the wearer’s weight. Differences in length measurements from benchtop impressions and from walking impressions created when the manufacturer’s reported shoe size was two sizes smaller than the wearer’s foot size were statistically significantly different from almost all other experimental groups for all impressions. Conversely, the study failed to detect statistically significant differences in width measurements from impressions, indicating that the factor of wearer foot size had a larger impact on toe-to-heel length measurements than on medial-to-lateral ball of the toe width measurements. Results also indicated that of the two outsoles included in this study (the Nike® Downshifter 11 and the Asics® Gel Dedicate 7), differences between Nike® benchtop impressions and Nike® walking impressions were always greater than differences between Asics® benchtop impressions and Asics® walking impressions. Since major differences in outsole chemical composition did not exist for these shoes, the greater change in physical size for the Nike® impressions is hypothesized to be due to other factors beyond the scope of this investigation, such as the depth of tread elements, the composition of the midsole, the geometric tread arrangement, and/or intended-end-use for the shoe. In summary, this research characterized the variation that can be expected when test impressions are created using different methods and when a foot/shoe size match or mismatch is present using the walking method. Based on the findings presented in this paper, best practice dictates that footwear analysts creating test impressions using the walking method should avoid wearing a manufacturer’s reported shoe size that is two or more sizes smaller than their foot size
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