93 research outputs found

    Fuel Injector: Air swirl characterization aerothermal modeling, phase 2, volume 2

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    A well integrated experimental/analytical investigation was conducted to provide benchmark quality data relevant to prefilming type airblast fuel nozzle and its interaction with combustor dome air swirler. The experimental investigation included a systematic study of both single-phase flows that involved single and twin co-axial jets with and without swirl. A two-component Phase Doppler Particle Analyzer (PDPA) equipment was used to document the interaction of single and co-axial air jets with glass beads that simulate nonevaporating spray and simultaneously avoid the complexities associated with fuel atomization processes and attendant issues about the specification of relevant boundary conditions. The interaction of jets with methanol spray produced by practical airblast nozzle was also documented in the spatial domain of practical interest. Model assessment activities included the use of three turbulence models (k-epsilon, algebraic second moment (ASM) and differential second moment (DSM)) for the carrier phase, deterministic or stochastic Lagrangian treatment of the dispersed phase, and advanced numerical schemes. Although qualitatively good comparison with data was obtained for most of the cases investigated, the model deficiencies in regard to modeled dissipation rate transport equation, single length scale, pressure-strain correlation, and other critical closure issues need to be resolved before one can achieve the degree of accuracy required to analytically design combustion systems

    Fuel injector: Air swirl characterization aerothermal modeling, phase 2, volume 1

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    A well integrated experimental/analytical investigation was conducted to provide benchmark quality relevant to a prefilming type airblast fuel nozzle and its interaction with the combustor dome air swirler. The experimental investigation included a systematic study of both single-phase flows that involved single and twin co-axial jets with and without swirl. A two-component Phase Doppler Particle Analyzer (PDPA) was used to document the interaction of single and co-axial air jets with glass beads that simulate nonevaporating spray and simultaneously avoid the complexities associated with fuel atomization processes and attendant issues about the specification of relevant boundary conditions. The interaction of jets with methanol spray produced by practical airblast nozzle was also documented in the spatial domain of practical interest. Model assessment activities included the use of three turbulence models (k-epsilon, algebraic second moment (ASM), and differential second moment (DSM)) for the carrier phase, deterministic or stochastic Lagrangian treatment of the dispersed phase, and advanced numerical schemes. Although qualitatively good comparison with data was obtained for most of the cases investigated, the model deficiencies in regard to modeled dissipation rate transport equation, single length scale, pressure-strain correlation, and other critical closure issues need to be resolved before one can achieve the degree of accuracy required to analytically design combustion systems

    Ubiquitous healthy diatoms in the deep sea confirm deep carbon injection by the biological pump

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    The role of the ocean as a sink for CO2 is partially dependent on the downward transport of phytoplankton cells packaged within fast-sinking particles. However, whether such fast-sinking mechanisms deliver fresh organic carbon down to the deep bathypelagic sea and whether this mechanism is prevalent across the ocean requires confirmation. Here we report the ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m in the deep dark ocean. Decay experiments with surface phytoplankton suggested that the large proportion (18%) of healthy photosynthetic cells observed, on average, in the dark ocean, requires transport times from a few days to a few weeks, corresponding to sinking rates (124–732 m d−1) comparable to those of fast-sinking aggregates and faecal pellets. These results confirm the expectation that fast-sinking mechanisms inject fresh organic carbon into the deep sea and that this is a prevalent process operating across the global oligotrophic ocean

    Aniqsaaq (To Breathe): Study protocol to develop and evaluate an Alaska Native family-based financial incentive intervention for smoking cessation

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    Background Alaska Native and American Indian (ANAI) communities in Alaska are disproportionately affected by commercial tobacco use. Financial incentive interventions promote cigarette smoking cessation, but family-level incentives have not been evaluated. We describe the study protocol to adapt and evaluate the effectiveness and implementation of a remotely delivered, family-based financial incentive intervention for cigarette smoking among Alaskan ANAI people. Methods The study has 3 phases: 1) qualitative interviews with ANAI adults who smoke, family members, and stakeholders to inform the intervention, 2) beta-test of the intervention, and 3) randomized controlled trial (RCT) evaluating intervention reach and effectiveness on verified, prolonged smoking abstinence at 6- and 12-months post-treatment. In the RCT, adult dyads (ANAI person who smokes [index participant] and family member) recruited throughout Alaska will be randomized to a no-incentives control condition (n = 328 dyads) or a 6-month incentive intervention (n = 328 dyads). All dyads will receive cessation support and family wellness materials. Smoking status will be assessed weekly for four weeks and at three and six months. Intervention index participants will receive escalating incentives for verified smoking abstinence at each time point (maximum $750 total); the family member will receive rewards of equal value. Results A community advisory committee contributed input on the study design and methods for relevance to ANAI people, particularly emphasizing the involvement of families. Conclusion Our study aligns with the strength and value AIAN people place on family. Findings, processes, and resources will inform how Indigenous family members can support smoking cessation within incentive interventions.Ye

    Quality of life in caregivers of patients with schizophrenia: A literature review

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    <p>Abstract</p> <p>Background</p> <p>A couple of decades ago, hospitals or psychiatric institutions were in charge of caring for patients with schizophrenia; however, nowadays this role is performed by one or more patient's relatives. Evidence shows that informal caregivers experience negative changes in their quality of life (QOL). The aim of this study is to review the main factors associated with the QOL of caregivers of people with schizophrenia.</p> <p>Methods</p> <p>A search through databases from journals published last decade between 1998 and 2008 was performed. In accordance with the inclusion criteria, titles and abstracts of citations obtained from the search were examined independently by two authors and irrelevant articles discarded. The full text of those studies considered relevant by either reviewer were obtained and assessed independently. Where differences of opinion rose they were resolved by discussion. Out of the 258 references, 37 were included in the review.</p> <p>Studies which assessed factors associated with caregivers of people with schizophrenia's quality of life were included and the information summarized.</p> <p>Results</p> <p>Evidence suggest that physical, emotional and economic distress affect negatively caregiver's QOL as a result of a number of unfulfilled needs such as, restoration of patient functioning in family and social roles, economic burden, lack of spare time, among other factors.</p> <p>Conclusion</p> <p>Decreased QOL may be associated with caregivers' burden, lack of social support, course of the disease and family relationships problems. In addition, in developing countries, QOL is affected by caregivers' economic burden. High quality research is needed in order to identify factors associated with QOL over time and testing the efficacy of interventions aiming to improve QOL in caregivers of patients with schizophrenia.</p

    Multidimensional access methods

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