543 research outputs found
Thomson scattering in a low-pressure neon mercury positive column
The electron density and the electron temperature in a low-pressure neon mercury positive column are determined using Thomson scattering. Special attention has been given to the stray light reduction in the Thomson scattering setup. The results are obtained in a discharge tube with a 26 mm diam, 10 mbar of neon, a mercury pressure inbetween 0.14 and 0.85 Pa, and an electric current ranging from 100 to 400 mA. The systematic error in the electron density is 15%–45%, the statistical error is 25%–35%. The total error in the electron temperature is 15%–35%. ©2001 American Institute of Physics
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Occupational cancer in Britain: Exposure assessment methodology
To estimate the current occupational cancer burden due to past exposures in Britain, estimates of the number of exposed workers at different levels are required, as well as risk estimates of cancer due to the exposures. This paper describes the methods and results for estimating the historical exposures. All occupational carcinogens or exposure circumstances classified by the International Agency for Research on Cancer as definite or probable human carcinogens and potentially to be found in British workplaces over the past 20–40 years were included in this study. Estimates of the number of people exposed by industrial sector were based predominantly on two sources of data, the CARcinogen EXposure (CAREX) database and the UK Labour Force Survey. Where possible, multiple and overlapping exposures were taken into account. Dose–response risk estimates were generally not available in the epidemiological literature for the cancer–exposure pairs in this study, and none of the sources available for obtaining the numbers exposed provided data by different levels of exposure. Industrial sectors were therefore assigned using expert judgement to ‘higher'- and ‘lower'-exposure groups based on the similarity of exposure to the population in the key epidemiological studies from which risk estimates had been selected. Estimates of historical exposure prevalence were obtained for 41 carcinogens or occupational circumstances. These include exposures to chemicals and metals, combustion products, other mixtures or groups of chemicals, mineral and biological dusts, physical agents and work patterns, as well as occupations and industries that have been associated with increased risk of cancer, but for which the causative agents are unknown. There were more than half a million workers exposed to each of six carcinogens (radon, solar radiation, crystalline silica, mineral oils, non-arsenical insecticides and 2,3,7,8-tetrachlorodibenzo-p-dioxin); other agents to which a large number of workers are exposed included benzene, diesel engine exhaust and environmental tobacco smoke. The study has highlighted several industrial sectors with large proportions of workers potentially exposed to multiple carcinogens. The relevant available data have been used to generate estimates of the prevalence of past exposure to occupational carcinogens to enable the occupational cancer burden in Britain to be estimated. These data are considered adequate for the present purpose, but new data on the prevalence and intensity of current occupational exposure to carcinogens should be collected to ensure that future policy decisions be based on reliable evidence
Dustiness and deagglomeration testing: interlaboratory comparison of systems for nanoparticle powders
Different types of aerosolization and deagglomeration testing systems exist for studying the properties of nanomaterial powders and their aerosols. However, results are dependent on the specific methods used. In order to have well-characterized aerosols, we require a better understanding of how system parameters and testing conditions influence the properties of the aerosols generated. In the present study, four experimental setups delivering different aerosolization energies were used to test the resultant aerosols of two distinct nanomaterials (hydrophobic and hydrophilic TiO2). The reproducibility of results within each system was good. However, the number concentrations and size distributions of the aerosols created varied across the four systems; for number concentrations, e.g., from 10(3) to 10(6) #/cm(3). Moreover, distinct differences were also observed between the two materials with different surface coatings. The article discusses how system characteristics and other pertinent conditions modify the test results. We propose using air velocity as a suitable proxy for estimating energy input levels in aerosolization systems. The information derived from this work will be especially useful for establishing standard operating procedures for testing nanopowders, as well as for estimating their release rates under different energy input conditions, which is relevant for occupational exposure
Orbifolded Konishi from the Mirror TBA
Starting with a discussion of the general applicability of the simplified
mirror TBA equations to simple deformations of the AdS_5 x S^5 superstring, we
proceed to study a specific type of orbifold to which the undeformed simplified
TBA equations directly apply. We then use this set of equations, as well as
Luscher's approach, to determine the NLO wrapping correction to the energy of
what we call the orbifolded Konishi state, and show that they perfectly agree.
In addition we discuss wrapping corrections to the ground state energy of the
orbifolded model under consideration.Comment: 26 pages, 5 figures, v2: corrected typos, added a short discussion on
the ground state of the model; as submitted to J. Phys.
Forgiveness of In-group Offenders in Christian Congregations
Religious communities, like other communities, are ripe for interpersonal offenses. We examined the degree to which group identification predicted forgiveness of an in-group offender. We examined the effects of a victim’s perception of his or her religious group identification as a state-specific personal variable on forgiveness by integrating Social Identity Theory into a model of Relational Spirituality (Davis, Hook, & Worthington, 2008) to help explain victim’s responses to transgressions within a religious context. Data were collected from members of Christian congregations from the mid-west region of the United States (Study 1, N = 63), and college students belonging to Christian congregations (Study 2, N = 376). Regression analyses demonstrated that even after statistically controlling for many religious and transgression-related variables, group identification with a congregation still predicted variance in revenge and benevolence toward an in-group offender after a transgression. Additionally, mediation analyses suggest group identification as one mechanism through which trait forgivingness relates to forgiveness of specific offenses. We discuss the importance of group identity in forgiving other in-group members in a religious community
Experiencing Grace: A Review of the Empirical Literature
Positive psychologists have used science to understand many virtues but have only just started to study grace, recently defined as ‘ . . . the gift of acceptance given unconditionally and voluntarily to an undeserving person by an unobligated giver’. The purpose of the current article is to provide a systematic review of all empirical studies (published and unpublished) on grace. Broadly, the empirical study of grace has focused on what people believe and how people experience both divine and human grace. Additionally, empirical attention has shifted to explore outcomes of grace-based interventions (e.g., congregation-wide interventions, marital interventions). In general, beliefs and experiences of grace were associated with (a) positive mental health outcomes, (b) religiosity, (c) virtue development, and (d) interpersonal functioning. Human grace has not been extensively explored and divine grace has been studied mostly among Christians; future studies should address these limitations and explore causal relationships
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