9,888 research outputs found

    Asian-Americans and the Internet

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    Presents findings from a survey conducted between March and December 2001, to document the use of the Internet by English speaking Asian Americans. Looks at differences in online use by age, gender, education, and economic status

    The DRIFT Directional Dark Matter Detector and First Studies of the Head-Tail Effect

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    Measurement of the direction of the elastic nuclear recoil track and ionization charge distribution along it, gives unique possibility for unambiguous detection of the dark matter WIMP particle. Within current radiation detection technologies only Time Projection Chambers filled with low pressure gas are capable of such measurement. Due to the character of the electronic and nuclear stopping powers of low energy nuclear recoils in the gas, an asymmetric ionization charge distribution along their tracks may be expected. Preliminary study of this effect, called Head-Tail, has been carried out here using the SRIM simulation program for Carbon and Sulfur in 40 Torr carbon disulfide, as relevant to the DRIFT detector. Investigations were focused on ion tracks projected onto the axis of the initial direction of motion in the energy range between 10 and 400 keV. Results indicate the likely existence of an asymmetry influenced by two competing effects: the nature of the stopping power and range straggling. The former tends to result in the Tail being greater than the Head and the latter the reverse. It has been found that for projected tracks the mean position of the ionization charge flows from 'head' to 'tail' with the magnitude depending on the ion type and its energy.Comment: To appear in the proceedings of Dark 2007 Sixth International Heidelberg conference on "Dark Matter in Astro & Particle Physics", Sydney, Australia 24th-28th September 200

    Reduction of Coincident Photomultiplier Noise Relevant to Astroparticle Physics Experiment

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    In low background and low threshold particle astrophysics experiments using observation of Cherenkov or scintillation light it is common to use pairs or arrays of photomultipliers operated in coincidence. In such circumstances, for instance in dark matter and neutrino experiments, unexpected PMT noise events have been observed, probably arising from generation of light from one PMT being detected by one or more other PMTs. We describe here experimental investigation of such coincident noise events and development of new techniques to remove them using novel pulse shape discrimination procedures. When applied to data from a low background NaI detector with facing PMTs the new procedures are found to improve noise rejection by a factor of 20 over conventional techniques, with significantly reduced loss of signal events.Comment: Submitted to NIM

    The Transformation Process of Fathers of Children with Disabilities: An Exploratory Case Study

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    While the vital role that fathers play in the development of their children is emphasized in recent literature, the majority of research relative to child development focuses on mothers. This imbalance is even more evident relative to research with parents of children with disabilities, leaving human service providers with few evidence based practices for appropriately addressing the needs of fathers raising children with disabilities. Research suggests that having a child with a disability, while challenging, can also have a significant positive impact on the family system and potentially offer a transformational experience for the parent. Guided by a theoretical model of transformational outcomes, the purpose of this qualitative case study was to investigate how two veteran fathers of children with disabilities describe their transformative process. Using qualitative inquiry methods, the fathers’ were interviewed and their narratives were transcribed and analyzed to discover emerging themes. Findings indicated that laughter was a prominent emotion throughout the narrative and that the fathers used both positive and negative descriptors to define their experiences. Implications of these findings for human service professionals supporting families of children with disabilities are discussed. Attending to the unique needs of fathers can improve the overall functionality of the family system

    The Dot-com Meltdown and the Web

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    Presents findings from a survey conducted between August and September 2001. Looks at how the collapse of the dot-com economy has had tangible effects on personal lives, and how online Americans have made quick adjustments to the changing Web environment
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