61 research outputs found

    Damage and strain in epitaxial GexSi1–x films irradiated with Si

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    The damage and strain induced by irradiation of both relaxed and pseudomorphic GexSi1–x films on Si(100) with 100 keV 28Si ions at room temperature have been studied by MeV 4He channeling spectrometry and x-ray double-crystal diffractometry. The ion energy was chosen to confine the major damage to the films. The results are compared with experiments for room temprature Si irradiation of Si(100) and Ge(100). The maximum relative damage created in low-Ge content films studied here (x=10%, 13%, 15%, 20%, and 22%) is considerably higher than the values obtained by interpolating between the results for relative damage in Si-irradiated single crystal Si and Ge. This, together with other facts, indicates that a relatively small fraction of Ge in Si has a significant stabilizing effect on the retained damage generated by room-temperature irradiation with Si ions. The damage induced by irradiation produces positive perpendicular strain in GexSi1–x, which superimposes on the intrinsic positive perpendicular strain of the pseudomorphic or partially relaxed films. In all of the cases studied here, the induced maximum perpendicular strain and the maximum relative damage initially increase slowly with the dose, but start to rise at an accelerated rate above a threshold value of ~0.15% and 15%, respectively, until the samples are amorphized. The pre-existing pseudomorphic strain in the GexSi1–x film does not significantly influence the maximum relative damage created by Si ion irradiation for all doses and x values. The relationship between the induced maximum perpendicular strain and the maximum relative damage differs from that found in bulk Si(100) and Ge(100)

    Using the Mystery Motivator to Improve Child Bedtime Compliance

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    Child bedtime problems are commonly reported by parents. A number of behavioral techniques, including extinction of tantrum behaviors, reinforcement of compliant bedtime, and implementation of consistent bedtime routines have been successful in improving bedtime compliance. The present study examined the effects of the Mystery Motivator (MM), a behavioral contract designed to remediate bedtime problems by delivering random reinforcement. Emphasis was placed on the optimal use of clinical intervention by enlisting parents as primary change agents in the home setting. Three adults and their four children, aged 3-5 years, participated. Three of the four children showed substantial changes in both time out of bed and bedtime noncompliance between baseline and treatment phases. A fourth child showed less improvement. Parent participants demonstrated understanding of the materials and successfully implemented the home program. Both parent and child participants rated the Mystery Motivator reinforcement system as an acceptable intervention

    Estimating the Accuracy of Anal Cytology in the Presence of an Imperfect Reference Standard

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    Background: The study aim is to estimate sensitivity and specificity of anal cytology for histologic HSIL in analyses adjusted for the imperfect biopsy reference standard. Methods and Principal Findings: Retrospective cohort study of an anal dysplasia screening program for HIV infected adults. We estimated the prevalence of histologic HSIL by concurrent cytology category and the associated cytology ROC area. Cytology operating characteristics for HSIL were estimated and adjusted for the imperfect reference standard by 3 methodologies. The study cohort included 261 patients with 3 available measures: (1) referral cytology; (2) HRA cytology; and (3) HRA directed biopsy. The prevalence of biopsy HSIL varied according to the concurrent HRA cytology result: 64.5

    Study of Jet Quenching with Z plus jet Correlations in Pb-Pb and pp Collisions at root s(NN)=5.02 TeV

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