199,974 research outputs found
Interior of M. P. [Methodist Protestant] Church, Adrian, Mich.
No full textColor printed image of interior of church looking toward front/podium. Image by “Metler, Foto.” Postcard addressed to Miss Elma Ellis, Marlette, Mich., from Nellie Reece. Posted Sep 10. Year not visible. 3 ½ x 5 ½ in
Young women's use of a microbicide surrogate: The complex influence of relationship characteristics and perceived male partners' evaluations
No full textThis is the post-print version of the article. The official published version can be found at the link below.Currently in clinical trials, vaginal microbicides are proposed as a female-initiated method of sexually transmitted infection prevention. Much of microbicide acceptability research has been conducted outside of the United States and frequently without consideration of the social interaction between sex partners, ignoring the complex gender and power structures often inherent in young women’s (heterosexual) relationships. Accordingly, the purpose of this study was to build on existing microbicide research by exploring the role of male partners and relationship characteristics on young women’s use of a microbicide surrogate, an inert vaginal moisturizer (VM), in a large city in the United States. Individual semi-structured interviews were conducted with 40 young women (18–23 years old; 85% African American; 47.5% mothers) following use of the VM during coital events for a 4 week period. Overall, the results indicated that relationship dynamics and perceptions of male partners influenced VM evaluation. These two factors suggest that relationship context will need to be considered in the promotion of vaginal microbicides. The findings offer insights into how future acceptability and use of microbicides will be influenced by gendered power dynamics. The results also underscore the importance of incorporating men into microbicide promotion efforts while encouraging a dialogue that focuses attention on power inequities that can exist in heterosexual relationships. Detailed understanding of these issues is essential for successful microbicide acceptability, social marketing, education, and use.This study was funded by a grant from National Institutes of Health (NIHU19AI 31494) as well as research awards to the first author: Friends of the Kinsey Institute Research Grant Award, Indiana University’s School of HPER Graduate Student Grant-in-Aid of Research Award, William L. Yarber Sexual Health Fellowship, and the Indiana University Graduate and Professional Student Organization Research Grant
A Multi-Dimensional Trust Model for Heterogeneous Contract Observations
No full textIn this paper we develop a novel probabilistic model of computational trust that allows agents to exchange and combine reputation reports over heterogeneous, correlated multi-dimensional contracts. We consider the specific case of an agent attempting to procure a bundle of services that are subject to correlated quality of service failures (e.g. due to use of shared resources or infrastructure), and where the direct experience of other agents within the system consists of contracts over different combinations of these services. To this end, we present a formalism based on the Kalman filter that represents trust as a vector estimate of the probability that each service will be successfully delivered, and a covariance matrix that describes the uncertainty and correlations between these probabilities. We describe how the agents’ direct experiences of contract outcomes can be represented and combined within this formalism, and we empirically demonstrate that our formalism provides significantly better trustworthiness estimates than the alternative of using separate single-dimensional trust models for each separate service (where information regarding the correlations between each estimate is lost)
The assessment of effective dose equivalent using personnel dosimeters
No full textVita.From January 1994, U.S. nuclear plants must develop a technically rigorous approach for determining the effective dose equivalent for their w ork forces. This dissertation explains concepts associated with effective dose equivalent and describes how to assess effective dose equivalent by using conventional personnel dosimetry measurements. A M onte Carlo computer code, MCNP, was used to calculate photon transport through a model o f the human body. Published mathematical phantoms o f the human adult male and female were used to simulate irradiation from a variety o f external radiation sources in order to calculate organ and tissue doses, as well as effective dose equivalent using weighting factors from ICRP Publication 26. The radiation sources considered were broad parallel photon beams incident on the body from 91 different angles and isotropic point sources located at 234 different locations in contact with or near the body. M onoenergetic photons o f 0.08, 0.3, and 1.0 M eV w ere considered for both sources. Personnel dosimeters were simulated on the surface o f the body and exposed to with the same sources. From these data, the influence o f dosimeter position on dosimeter response was investigated. Different algorithms for assessing effective dose equivalent from personnel dosimeter responses were proposed and evaluated. The results indicate that the current single-badge approach is satisfactory for m ost common exposure situations encountered in nuclear plants, but additional conversion factors may be used when more accurate results become desirable. For uncommon exposures involving source situated at the back o f the body or source located overhead, the current approach o f using multi-badges and assigning the highest dose is overly conservative and unnecessary expensive. F or these uncommon exposures, a new algorithm, based on two dosimeters, one on the front o f the body and another one on the back o f the body, has been shown to yield conservative assessment o f effective dose equivalent. The data presented in this dissertation have many applications in nuclear industry and can be used as a basis by national regulatory agencies and other radiation protection organizations in issuing guidances and recommendations for assessing effective dose equivalent from external photon radiations
Advanced neutron irradiation system using Texas A&M University Nuclear Science Center Reactor
No full textA heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and neutron monitoring system, a sample transfer system, and interchangeable filters. This system was installed in the irradiation cell of the Texas A&M University Nuclear Science Center Reactor (NSCR).
By increasing the thickness of the lead-bismuth alloy, the neutron spectra were shifted into lower energies by the scattering interactions of fast neutrons with the alloy. It is possible, therefore, by changing the alloy thickness, to produce distinctly different dose weighted neutron spectra inside the exposure cave of the FNIS. The calculated neutron spectra showed close agreement with the results of activation foil measurements, unfolded by SAND-II close to the cell window. However, there was a considerable less agreement for locations far away from the cell window. Even though the magnitude of values such as neutron flux and tissue kerma rates in air differed, the weighted average neutron energies showed close agreement between the MCNP and SAND-II since the normalized neutron spectra were in a good agreement each other.
A paired ion chamber system was constructed, one with a tissue equivalent plastic (A-150) and propane gas for total dose monitoring, and another with graphite and argon for photon dose monitoring. Using the pair of detectors, the neutron to gamma ratio can be inferred. With the 20 cm-thick FNIS, the absorbed dose rates of neutrons measured with the paired ion chamber method and calculated with the SAND-II results were 13.7 ?? 0.02 Gy/min and 15.5 Gy/min, respectively. The absorbed dose rate of photons and the gamma contribution to total dose were 6.7??10-1 ?? 1.3??10-1 Gy/min and 4.7%, respectively. However, the estimated gamma contribution to total dose varied between 3.6 % to 6.6 % as the assumed neutron sensitivity to the graphite detector was changed from 0.01 to 0.03
Byron Herbert Reece: What Can We in the 21st Century Learn from ‘Georgia’s Farmer Poet’?
No full textByron Herbert Reece was born in 1917 in a cabin on a small farm near Choestoe, in Union County, Georgia. From the mid 1940s to the mid 1950s he published four books of poems and two novels, all with E.P. Dutton in New York, and all receiving generally favorable reviews. Syndicated reviewer Edward M. Case in a 1955 review declared, “It seems to me that with the exception of Robert Frost, Reece is our greatest living poet, and even Frost is not so pure a lyricist, nor as strong and lonely a voice.” Reece is unquestionably the bard of the North Georgia Mountains, but his scope and his appeal are much wider. Though Reece was a product of and participant in his tiny community of Choestoe, his solitary nature as a writer, exacerbated by his tuberculosis, along with his wider experience of the world, afforded him a larger and more objective perspective on his community. His poems and novels together comprise a richly detailed narrative of an Appalachian farming community confronting the modern world as seen through the penetrating eyes of an intimate stranger
Guest editorial: GlaCERCo: Glass and ceramic composites for high technology applications - Marie Curie initial training network
No full textRumours and Reputation: Evaluating Multi-Dimensional Trust within a Decentralised Reputation System
No full textIn this paper we develop a novel probabilistic model of computational trust that explicitly deals with correlated multi-dimensional contracts. Our starting point is to consider an agent attempting to estimate the utility of a contract, and we show that this leads to a model of computational trust whereby an agent must determine a vector of estimates that represent the probability that any dimension of the contract will be successfully fulfilled, and a covariance matrix that describes the uncertainty and correlations in these probabilities. We present a formalism based on the Dirichlet distribution that allows an agent to calculate these probabilities and correlations from their direct experience of contract outcomes, and we show that this leads to superior estimates compared to an alternative approach using multiple independent beta distributions. We then show how agents may use the sufficient statistics of this Dirichlet distribution to communicate and fuse reputation within a decentralised reputation system. Finally, we present a novel solution to the problem of rumour propagation within such systems. This solution uses the notion of private and shared information, and provides estimates consistent with a centralised reputation system, whilst maintaining the anonymity of the agents, and avoiding bias and overconfidence
Reduced thermal conductivity by nanoscale intergrowths in perovskite like layered structure La2Ti2O
No full textThe effect of substitution and oxidation-reduction on the thermal conductivity of perovskite-like layered structure (PLS) ceramics was investigated in relation to mass contrast and non-stoichiometry. Sr (acceptor) was substituted on the A site, while Ta (donor) was substituted on the B site of La2Ti2O7. Substitution in PLS materials creates atomic scale disorders to accommodate the non-stoichiometry. High resolution transmission electron microscopy and X ray diffraction revealed that acceptor substitution in La2Ti2O7 produced nanoscale intergrowths of n?=?5 layered phase, while donor substitution produced nanoscale intergrowths of n?=?3 layered phase. As a result of these nanoscale intergrowths, the thermal conductivity value reduced by as much as ?20%. Pure La2Ti2O7 has a thermal conductivity value of ?1.3?W/m K which dropped to a value of ?1.12?W/m K for Sr doped La2Ti2O7 and ?0.93?W/m K for Ta doped La2Ti2O7 at 573?K.Aerospace Structures & MaterialsAerospace Engineerin
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