158 research outputs found

    Propulsion Study for Small Transport Aircraft Technology (STAT)

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    Propulsion requirements were determined for 0.5 and 0.7 Mach aircraft. Sensitivity studies were conducted on both these aircraft to determine parametrically the influence of propulsion characteristics on aircraft size and direct operating cost (DOC). Candidate technology elements and design features were identified and parametric studies conducted to select the STAT advanced engine cycle. Trade off studies were conducted to determine those advanced technologies and design features that would offer a reduction in DOC for operation of the STAT engines. These features were incorporated in the two STAT engines. A benefit assessment was conducted comparing the STAT engines to current technology engines of the same power and to 1985 derivatives of the current technology engines. Research and development programs were recommended as part of an overall technology development plan to ensure that full commercial development of the STAT engines could be initiated in 1988

    Study of an advanced General Aviation Turbine Engine (GATE)

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    The best technology program for a small, economically viable gas turbine engine applicable to the general aviation helicopter and aircraft market for 1985-1990 was studied. Turboshaft and turboprop engines in the 112 to 746 kW (150 to 1000 hp) range and turbofan engines up to 6672 N (1500 lbf) thrust were considered. A good market for new turbine engines was predicted for 1988 providing aircraft are designed to capitalize on the advantages of the turbine engine. Parametric engine families were defined in terms of design and off-design performance, mass, and cost. These were evaluated in aircraft design missions selected to represent important market segments for fixed and rotary-wing applications. Payoff parameters influenced by engine cycle and configuration changes were aircraft gross mass, acquisition cost, total cost of ownership, and cash flow. Significant advantage over a current technology, small gas turbine engines was found especially in cost of ownership and fuel economy for airframes incorporating an air-cooled high-pressure ratio engine. A power class of 373 kW (500 hp) was recommended as the next frontier for technology advance where large improvements in fuel economy and engine mass appear possible through component research and development

    Participant engagement in a community health worker-delivered intervention and type 2 diabetes clinical outcomes: a quasiexperimental study in MexicanAmericans

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    Objectives This study helps to fill the existing research gap related to participant engagement in behavioural interventions and diabetes management. We examined type 2 diabetes control over time among Mexican Americans by level of engagement in a chronic care management (CCM) program that included community health worker (CHW)-delivered multilevel interventions. The programme complemented clinical care and promoted behaviour changes to improve diabetes self-management. Design Quasiexperimental study. Setting The study was implemented in the Rio Grande Valley region in the USA. Recruitment was conducted in clinics and community events. All other visits were provided in participant homes and community locations. Participants 5649 adults (aged ≥18 years) with poorly controlled type 2 diabetes who enrolled in a community-delivered CCM programme between September 2013 and 2018. Interventions The intervention comprised two components: CHW home visits conducted every 3 months and diabetes self-management education (DSME) classes provided in community locations. Primary outcome measures The primary outcome was haemoglobin A1c (HbA1c) measured at baseline every 3 months for up to 24 months. We first examined changes in HbA1c levels over time. The number of completed CHW and DSME encounters was used to classify participants into engagement groups—high engagement defined as ≥10 encounters (n=2952); low engagement defined as 1–9 encounters (n=2697). We used univariable and multivariable longitudinal linear regression models with a generalised estimating equation method. We tested interactions between engagement groups and time. Results Participants’ mean HbA1c decreased from 10.20% at baseline to 8.93% (p Conclusions Higher engagement in the CCM programme delivered by CHWs and coordinated with clinical care was associated with beneficial improvements in type 2 diabetes control, but both engagement groups showed strong improvements

    An expanded chronic care management approach to multiple chronic conditions in Hispanics using community health workers as community extenders in the Rio Grande Valley of Texas

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    Introduction The synergistic negative effects of type 2 diabetes (T2DM) and hypertension increases all-cause mortality and the medical complexity of management, which disproportionately impact Hispanics who face barriers to healthcare access. The Salud y Vida intervention was delivered to Hispanic adults living along the Texas-Mexico Border with comorbid poorly controlled T2DM and hypertension. The Salud y Vida multicomponent intervention incorporated community health workers (CHWs) into an expanded chronic care management model to deliver home-based follow-up visits and provided community-based diabetes self-management education. Methods We conducted multivariable longitudinal analysis to examine the longitudinal intervention effect on reducing systolic and diastolic blood pressure among 3806 participants enrolled between 2013 and 2019. Participants were compared according to their program participation as either higher (≥ 10 combined educational classes and CHW visits) or lower engagement (\u3c10 \u3eencounters). Data was collected between 2013 and 2020. Results Baseline mean systolic and diastolic blood pressure were 138 and 81 mmHg respectively. There were overall improvements in systolic (−6.49; 95% CI = [−7.13, −5.85]; p \u3c 0.001) and diastolic blood pressure (−3.97; 95% CI = [−4.37, −3.56]; p \u3c 0.001). The higher engagement group had greater systolic blood pressure reduction at 3 months (adjusted mean difference = −1.8 mmHg; 95% CI = [−3.2, −0.3]; p = 0.016) and at 15 month follow-up (adjusted mean difference = −2.3 mmHg; 95% CI = [−4.2, −0.39]; p = 0.0225) compared to the lower engagement group. Conclusion This intervention, tested and delivered in a real-world setting, provides an example of how CHW integration into an expanded chronic care model can improve blood pressure outcomes for individuals with co-morbidities

    An Expanded Chronic Care Management approach to Multiple Chronic Conditions in Hispanics Using Community Health Workers as Community Extenders in the Rio Grande Valley of Texas

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    INTRODUCTION: The synergistic negative effects of type 2 diabetes (T2DM) and hypertension increases all-cause mortality and the medical complexity of management, which disproportionately impact Hispanics who face barriers to healthcare access. The Salud y Vida intervention was delivered to Hispanic adults living along the Texas-Mexico Border with comorbid poorly controlled T2DM and hypertension. The Salud y Vida multicomponent intervention incorporated community health workers (CHWs) into an expanded chronic care management model to deliver home-based follow-up visits and provided community-based diabetes self-management education. METHODS: We conducted multivariable longitudinal analysis to examine the longitudinal intervention effect on reducing systolic and diastolic blood pressure among 3806 participants enrolled between 2013 and 2019. Participants were compared according to their program participation as either higher (≥ 10 combined educational classes and CHW visits) or lower engagement (\u3c10 \u3eencounters). Data was collected between 2013 and 2020. RESULTS: Baseline mean systolic and diastolic blood pressure were 138 and 81 mmHg respectively. There were overall improvements in systolic (-6.49; 95% CI = [-7.13, -5.85]; p \u3c 0.001) and diastolic blood pressure (-3.97; 95% CI = [-4.37, -3.56]; p \u3c 0.001). The higher engagement group had greater systolic blood pressure reduction at 3 months (adjusted mean difference = -1.8 mmHg; 95% CI = [-3.2, -0.3]; p = 0.016) and at 15 month follow-up (adjusted mean difference = -2.3 mmHg; 95% CI = [-4.2, -0.39]; p = 0.0225) compared to the lower engagement group. CONCLUSION: This intervention, tested and delivered in a real-world setting, provides an example of how CHW integration into an expanded chronic care model can improve blood pressure outcomes for individuals with co-morbidities

    Convective nature of planimetric instability in meandering river dynamics

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    The convective nature of the linear instability of meandering river dynamics is analytically demonstrated and the corresponding Green's function is derived. The wave packet due to impulsive disturbance migrates along a river either downstream or upstream, depending on the subresonant or superresonant conditions. The influence of the parameters that govern the meandering process is shown and the role of the fluid dynamic detail used to describe the morphodynamic problem is discussed. A numerical simulation of the river planimetry is also develope

    On the Design of an Intelligent Sensor Network for Flash Flood Monitoring, Diagnosis and Management in Urban Areas

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    We propose an intelligent sensor system based on a new sensing methodology, relying also on 3D map reconstruction techniques, for computing with high precision, in real-time and without human intervention the parameters needed for stream-flow computation: water levels, morphology of the streams of all potentially flooded areas by each controlled stream. The collected data will be continuously transmitted, through a communication infrastructure, to software agents designed to compute the stream-flow and to quantify the spatial distribution of flood risk for each controlled watershed. The computed risks, together with other data coming from other sources (barometric sensors, camera operators of public organizations, emergency agencies, private citizens), will be analyzed by a diagnostic decision system implementing a risk-alert scheduling strategy. This system will be able to diagnose the health state of the controlled environment and to define specialized alarm levels for each potentially interested area that will be used to alert all citizens (ubiquity) locally present (alerting locality).© 2014 Published by Elsevier B.V. Open access under CC BY-NC-ND licenseAncona, M.; Corradi, N.; Dellacasa, A.; Delzanno, G.; Dugelay, J.; Federici, B.; Gourbesville, P.... (2014). On the Design of an Intelligent Sensor Network for Flash Flood Monitoring, Diagnosis and Management in Urban Areas. Procedia Computer Science. 32:941-946. doi:10.1016/j.procs.2014.05.515S9419463
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