Thermoacoustic Instabilities of Hydrogen-Enriched Partially Premixed Flames in a Swirl Combustor

2021 ◽  
Author(s):  
Y. Gong ◽  
D. Fredrich ◽  
A. J. Marquis ◽  
W. P. Jones ◽  
I. Boxx
Keyword(s):  
Field Method ◽  
The Self ◽  
Chamber Pressure ◽  
Stochastic Field ◽  
Cross Sectional ◽  
Swirl Combustor ◽  
Combustion Dynamics ◽  
Thermoacoustic Instabilities ◽  
Chemical Reaction Mechanism ◽  
Swirling Flames

Abstract Large eddy simulations (LES) of premixed hydrogen-enriched swirling flames were performed to investigate the flame topology and combustion instabilities with different hydrogen concentrations. A compressible LES approach is utilised to account for the self-excited combustion dynamics. A transported probability density function (pd f) approach is adopted to account for sub-grid scale (sgs) turbulence-chemistry interaction, and the solution to the joint sgs – pd f evolution equation of the scalars is obtained by the stochastic field method. The chemistry is represented using a reduced chemical reaction mechanism containing 15 reaction steps and 19 species. The results revealed that as the concentration of hydrogen increases, the flame is shortened in the injecting direction and more confined in the cross-sectional direction, which is consistent with experimental observations. The self-excited limit-cycle oscillations for all considered cases were successfully reproduced, with the predicted peak frequencies of the chamber pressure spectra in excellent agreement with the measured values. The feedback loop of the oscillations is successfully captured and analysed with the temporal evolution of axial velocity and heat release presented.

scholarly journals Augmenting the Clinical Data Sources for Enigmatic Diseases: A Cross-Sectional Study of Self-Tracking Data and Clinical Documentation in Endometriosis

2020 ◽  
Vol 11 (05) ◽  
pp. 769-784
Author(s):  
Ipek Ensari ◽  
Adrienne Pichon ◽  
Sharon Lipsky-Gorman ◽  
Suzanne Bakken ◽  
Noémie Elhadad
Keyword(s):  
Additional Data ◽  
Intraclass Correlation ◽  
Management Strategies ◽  
The Self ◽  
Self Management ◽  
Cross Sectional ◽  
Two Samples ◽  
Data Source ◽  
Daily Function ◽  
Over Time

Abstract Background Self-tracking through mobile health technology can augment the electronic health record (EHR) as an additional data source by providing direct patient input. This can be particularly useful in the context of enigmatic diseases and further promote patient engagement. Objectives This study aimed to investigate the additional information that can be gained through direct patient input on poorly understood diseases, beyond what is already documented in the EHR. Methods This was an observational study including two samples with a clinically confirmed endometriosis diagnosis. We analyzed data from 6,925 women with endometriosis using a research app for tracking endometriosis to assess prevalence of self-reported pain problems, between- and within-person variability in pain over time, endometriosis-affected tasks of daily function, and self-management strategies. We analyzed data from 4,389 patients identified through a large metropolitan hospital EHR to compare pain problems with the self-tracking app and to identify unique data elements that can be contributed via patient self-tracking. Results Pelvic pain was the most prevalent problem in the self-tracking sample (57.3%), followed by gastrointestinal-related (55.9%) and lower back (49.2%) pain. Unique problems that were captured by self-tracking included pain in ovaries (43.7%) and uterus (37.2%). Pain experience was highly variable both across and within participants over time. Within-person variation accounted for 58% of the total variance in pain scores, and was large in magnitude, based on the ratio of within- to between-person variability (0.92) and the intraclass correlation (0.42). Work was the most affected daily function task (49%), and there was significant within- and between-person variability in self-management effectiveness. Prevalence rates in the EHR were significantly lower, with abdominal pain being the most prevalent (36.5%). Conclusion For enigmatic diseases, patient self-tracking as an additional data source complementary to EHR can enable learning from the patient to more accurately and comprehensively evaluate patient health history and status.

scholarly journals Comparative Study of Chemosensory Dysfunction in COVID-19 in 2 Geographically Distinct Regions

2021 ◽  
pp. 014556132110001
Author(s):  
Daniel J. Lee ◽  
Daniella Daliyot ◽  
Ri Wang ◽  
Joel Lockwood ◽  
Paul Das ◽  
...  
Keyword(s):  
Comparative Study ◽  
Symptom Onset ◽  
Subgroup Analysis ◽  
Primary Outcome ◽  
Cross Sectional Study ◽  
The Self ◽  
Sectional Study ◽  
Cross Sectional ◽  
Specific Data ◽  
Geographical Regions

Objective: To directly compare the prevalence of chemosensory dysfunction (smell and taste) in geographically distinct regions with the same questionnaires. Methods: A cross-sectional study was performed to evaluate the self-reported symptoms among adults (older than 18 years) who underwent COVID-19 testing at an ambulatory assessment center in Canada and at a hospital in Israel between March 16, 2020, and August 19, 2020. The primary outcome was the prevalence of self-reported chemosensory dysfunction (anosmia/hypomsia and dysgeusia/ageusia). Subgroup analysis was performed to evaluate the prevalence of chemosensory deficits among the outpatients. Results: We identified a total of 350 COVID-19–positive patients (138 Canadians and 212 Israelis). The overall prevalence of chemosensory dysfunction was 47.1%. There was a higher proportion of chemosensory deficits among Canadians compared to Israelis (66.7% vs 34.4%, P < .01). A subgroup analysis for outpatients (never hospitalized) still identified a higher prevalence of chemosensory dysfunction among Canadians compared to Israelis (68.2% vs 36.1%, P < 0.01). A majority of patients recovered their sense of smell after 4 weeks of symptom onset. Conclusion: Although the prevalence of chemosensory deficit in COVID-19 was found to be similar to previously published reports, the prevalence can vary significantly across different geographical regions. Therefore, it is important to obtain regionally specific data so that the symptom of anosmia/dysgeusia can be used as a guide for screening for the clinical diagnosis of COVID-19.

scholarly journals Factors affecting the self-rated health of immigrant women married to native men and raising children in South Korea: a cross-sectional study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Bookyoung Kim ◽  
Kyung-Bok Son
Keyword(s):  
South Korea ◽  
Immigrant Women ◽  
Country Of Origin ◽  
The Self ◽  
Chinese Han ◽  
Cross Sectional ◽  
Raising Children ◽  
Medical Needs ◽  
Self Rated Health ◽  
Korean Chinese

Abstract Background Since the influx of international immigrants to South Korea (Korea) in the 1980s, the number of immigrants married to native Koreans has increased substantially over the last 30 years. This study aims to provide recent evidence on the self-rated health of immigrant women married to native men and raising children. We evaluated the self-rated health of immigrant women sorted by their country of origin and elucidated factors that affect their self-rated health. Methods Data were obtained from the 2015 Korean National Multi-Cultural Family Survey. From the survey, a total of 6960 Korean-Chinese, Han-Chinese, Japanese, Vietnamese, and Filipino women were identified and a series of logistic regressions was conducted to elucidate factors that affected the self-rated health of immigrant women. Results The majority of immigrant women in Korea perceived that they are healthy. However, the self-rated health of immigrant women varied by country of origin. Korean-Chinese and Japanese immigrants are less likely to perceive that they are healthy compared with Filipino and Vietnamese immigrants. We identified several factors at the individual, household, and community levels and found that the majority of them are likely to be ethnic dependent. However, satisfaction with husband and experience of unmet medical needs presented consistent results in the five ethnicity groups. Conclusions Programs that strengthen spousal relationships and policies to enhance access to healthcare could be prioritized options to improve the self-rated health of immigrant women in Korea.

scholarly journals Using the Self-Organising Map to Identify Regularities across Country-Specific Housing-Market Contexts

10.1068/b3186 ◽  
2005 ◽  
Vol 32 (1) ◽  
pp. 89-110 ◽  
Author(s):  
Tom Kauko
Keyword(s):  
Housing Market ◽  
Semiparametric Regression ◽  
The Self ◽  
Cross Sectional ◽  
Public And Private ◽  
Institutional Differences ◽  
Market Fundamentals ◽  
Self Organising Map ◽  
Public And Private Sector ◽  
Housing Submarkets

The aim of exploring and monitoring housing-market fundamentals (prices, dwelling features, area density, residents, and so on) on a macrolocational level relates to both public and private sector policymaking. Housing market segmentation (that is, the emergence of housing submarkets), a concept with increasing relevance, is defined as the differentiation of housing in terms of the income and preferences of the residents and in terms of administrative circumstances. In order to capture such segmentation empirically, the author applies a fairly new and emerging technique known as the ‘self-organising’ map (SOM), or ‘Kohonen map’. The SOM is a type of (artificial) neural network—a nonlinear and flexible (that is, nonparametric or semiparametric) regression and ‘machine learning’ technique. By utilising the ability of the SOM to visualise patterns, one can analyse various dimensions within the variation of the dataset. Segmentation may then be detected depending on the resulting patterns across the map layers, each of which represents the data variation for one input variable. Utilising an inductive modelling strategy, the author runs cross-sectional and nationwide data on the owner-occupied housing markets of Finland (documentation presented elsewhere), the Netherlands, and Hungary with the SOM technique. On the basis of the resulting configurations certain regularities (similarities and differences) across the three national contexts are identified. In all three cases the segments are determined by physical and institutional differences between the housing bundles and localities. The exercise demonstrates how the inductive SOM-based approach is well-suited for illustrating the contextual factors that determine housing market structure.

Knowledge and attitudes regarding the self-use of pain medications in Saudi Arabia: A cross-sectional study

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
MawadahM Magadmi ◽  
RaniaM Magadmi ◽  
FatemahO Kamel ◽  
MagdaM Hagras ◽  
HwraaI Alhmied ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Cross Sectional Study ◽  
The Self ◽  
Sectional Study ◽  
Cross Sectional ◽  
Knowledge And Attitudes ◽  
Pain Medications

Self-Care of African Immigrant Adults with Chronic Illness

2021 ◽  
pp. 105477382110561
Author(s):  
Onome Henry Osokpo ◽  
Lisa M. Lewis ◽  
Uchechukwu Ikeaba ◽  
Jesse Chittams ◽  
Frances K. Barg ◽  
...  
Keyword(s):  
Chronic Illness ◽  
Self Efficacy ◽  
Self Care ◽  
African Immigrants ◽  
Cross Sectional Study ◽  
The Self ◽  
Cross Sectional ◽  
Income Adequacy ◽  
The Us ◽  
Scale Scores

This cross-sectional study aims to describe the self-care of adult African immigrants in the US with chronic illness and explore the relationship between acculturation and self-care. A total of 88 African immigrants with chronic illness were enrolled. Self-care was measured with the Self Care of Chronic Illness Inventory v3 and the Self-Care Self-Efficacy scale. Scores are standardized 0 to 100 with scores >70 considered adequate. Acculturation was measured using a modified standardized acculturation instrument and predefined acculturation proxies. The self-care scores showed adequate self-care, with the mean scores of 78.6, 77.9, and 75.6 for self-care maintenance, monitoring, and management. Self-care self-efficacy mean score was 81.3. Acculturation was not significantly associated with self-care. Self-care self-efficacy was a strong determinant of self-care maintenance ( p < .0001), monitoring ( p < .0001), and management ( p < .0001). The perception of inadequate income was a significant determinant of poor self-care management ( p = .03). Self-care self-efficacy and perceived income adequacy were better determinants of self-care than acculturation.

scholarly journals Personality development from 12 to 18 years of age: changes in mean levels and structure of traits

2004 ◽  
Vol 18 (6) ◽  
pp. 445-462 ◽  
Author(s):  
Jüri Allik ◽  
Kaia Laidra ◽  
Anu Realo ◽  
Helle Pullmann
Keyword(s):  
Personality Traits ◽  
Personality Development ◽  
The Self ◽  
Age Changes ◽  
Cross Sectional ◽  
Adult Personality ◽  
12Th Grade ◽  
Self Reports ◽  
Change In The Mean ◽  
The Mean

The Estonian NEO‐FFI was administered to 2650 Estonian adolescents (1420 girls and 1230 boys) aged from 12 to 18 years and attending 6th, 8th, 10th, or 12th grade at secondary schools all over Estonia. Although the mean levels of personality traits of Estonian adolescents were quite similar to the respective scores of Estonian adults, there was a developmental gap in Agreeableness and Conscientiousness. Three of the five personality dispositions demonstrated a modest cross‐sectional change in the mean level of the trait scores: the level of Openness increased and the levels of Agreeableness and Conscientiousness decreased between 12 and 18 years of age. Although the five‐factor structure of personality was already recognizable in the sample of 12‐year‐old children, it demonstrated only an approximate congruence with the adult structure, suggesting that not all children of that age have developed abilities required for observing one's own personality dispositions and for giving reliable self‐reports on the basis of these observations. The self‐reported personality trait structure matures and becomes sufficiently differentiated around age 14–15 and grows to be practically indistinguishable from adult personality by the age of 16. Personality of adolescents becomes more differentiated with age: along with the growth of mental capacities the correlations among the personality traits and intelligence become smaller. Copyright © 2004 John Wiley & Sons, Ltd.

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