520 research outputs found

    Fraunhofer line discriminator Final report

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    Airborne Fraunhofer line discriminato

    The fixture and methodologies for evaluating vibration characteristics of hand-held pneumatic impact tools

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    A test fixture has been designed for the testing of hand held pneumatic impact tools. The test fixture was modeled after a one-degree of freedom mass-spring-damper system. The design of the test fixture allows for a broad range of testing scenarios intended to simulate the methods in which impact tools are used in industry. Sustained use and assembly operations performed by impact tools were simulated on the test fixture. Acceleration measurements at the impact tool\u27s handle and on the test fixture\u27s mass were recorded during the simulations. From the measurements made on the test fixture\u27s mass, the acceleration levels at the tool\u27s working surface were calculated using a force balance model of the impact tool and the test fixture. From the acceleration measurements made at the impact tool\u27s handle, vibration exposure levels were calculated for four and eight hour exposure time periods. Test procedures and methods incorporating the use of the test fixture are discussed. Results obtained during the testing process are provided

    Signals intelligence and the Washington Naval Conference: one element in the decision-making process

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    Call number: LD2668 .T4 1985 M37Master of Art

    Increasing Pediatric Hearing Aid Use: Considerations for Clinical Practice

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    Purpose: Hearing aid use can be variable for young children, and inconsistent wear time can undermine spoken language development. This study explored the effectiveness of hearing aid data logging (DL) awareness and coaching sessions on increasing hours of hearing aid use. We also collected qualitative data on challenges participants experienced managing hearing aid use. Method: We used a single-subject design that included three conditions, during a 6-week period, in the same order for each participant. Condition A was baseline, Condition B was DL monitoring alone, and Condition C was remote coaching calls plus DL monitoring. Results: Hours of hearing aid use increased for each child from baseline to the end of the study, ranging from 1.19 to 4.4 hr. Mothers reported that the coaching calls were beneficial and helped them identify and problem-solve issues. Conclusions: Parents were able to increase hours of hearing aid use with DL awareness and coaching support. Tele-audiology offers an opportunity to provide parents with more frequent support that can be individualized based on their situation, challenges, and family needs

    The effectiveness and efficiency of home-based nursing health promotion for older people: A review of the literature

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    Despite the large potential role that community nurses have in providing individualized health promotion to older people, there is a lack of consensus in the literature regarding this role's effectiveness and efficiency. This article presents a literature review and synthesis of 12 randomized controlled trials selected from 344 published studies on preventive home visitation programs for older people. The findings suggest that a diversity of home visiting interventions carried out by nurses can favorably affect health and functional status, mortality rates, use of hospitalization and nursing homes, and costs. Further research is needed that focuses on the outcomes of quality of life, mental health, social support, caregiver burden, the acceptability of intervention, and specific subgroups of clients who benefit most. Findings also indicate the need for a theoretical foundation, increased emphasis on health-promotion strategies, and more research using a more complete economic evaluation to establish efficiency

    High-frequency climate variability in the Holocene from a coastal-dome ice core in east-central Greenland

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    An ice core drilled on the Renland ice cap in east-central Greenland contains a continuous climate record dating through the last glacial period. The Renland record is valuable because the coastal environment is more likely to reflect regional sea surface conditions compared to inland Greenland ice cores that capture synoptic variability. Here we present the δ¹⁸O water isotope record for the Holocene, in which decadal-scale climate information is retained for the last 8 kyr, while the annual water isotope signal is preserved throughout the last 2.6 kyr. To investigate regional climate information preserved in the water isotope record, we apply spectral analysis techniques to a 300-year moving window to determine the mean strength of varying frequency bands through time. We find that the strength of 15–20-year δ¹⁸O variability exhibits a millennial-scale signal in line with the well-known Bond events. Comparison to other North Atlantic proxy records suggests that the 15–20-year variability may reflect fluctuating sea surface conditions throughout the Holocene, driven by changes in the strength of the Atlantic Meridional Overturning Circulation. Additional analysis of the seasonal signal over the last 2.6 kyr reveals that the winter δ¹⁸O signal has experienced a decreasing trend, while the summer signal has predominantly remained stable. The winter trend may correspond to an increase in Arctic sea ice cover, which is driven by a decrease in total annual insolation, and is also likely influenced by regional climate variables such as atmospheric and oceanic circulation. In the context of anthropogenic climate change, the winter trend may have important implications for feedback processes as sea ice retreats in the Arctic
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