Life prediction systems for critical rotating components
NASA Technical Reports Server (NTRS)
Cunningham, Susan E.
1993-01-01
With the advent of advanced materials in rotating gas turbine engine components, the methodologies for life prediction of these parts must also increase in sophistication and capability. Pratt & Whitney's view of generic requirements for composite component life prediction systems are presented, efforts underway to develop these systems are discussed, and industry participation in key areas requiring development is solicited.
Effect of Individual Component Life Distribution on Engine Life Prediction
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin V.; Hendricks, Robert C.; Soditus, Sherry M.
2003-01-01
The effect of individual engine component life distributions on engine life prediction was determined. A Weibull-based life and reliability analysis of the NASA Energy Efficient Engine was conducted. The engine s life at a 95 and 99.9 percent probability of survival was determined based upon the engine manufacturer s original life calculations and assumed values of each of the component s cumulative life distributions as represented by a Weibull slope. The lives of the high-pressure turbine (HPT) disks and blades were also evaluated individually and as a system in a similar manner. Knowing the statistical cumulative distribution of each engine component with reasonable engineering certainty is a condition precedent to predicting the life and reliability of an entire engine. The life of a system at a given reliability will be less than the lowest-lived component in the system at the same reliability (probability of survival). Where Weibull slopes of all the engine components are equal, the Weibull slope had a minimal effect on engine L(sub 0.1) life prediction. However, at a probability of survival of 95 percent (L(sub 5) life), life decreased with increasing Weibull slope.
Elastohydrodynamic principles applied to the design of helicopter components.
NASA Technical Reports Server (NTRS)
Townsend, D. P.
1973-01-01
Elastohydrodynamic principles affecting the lubrication of transmission components are presented and discussed. Surface temperatures of the transmission bearings and gears affect elastohydrodynamic film thickness. Traction forces and sliding as well as the inlet temperature determine surface temperatures. High contact ratio gears cause increased sliding and may run at higher surface temperatures. Component life is a function of the ratio of elastohydrodynamic film thickness to composite surface roughness. Lubricant starvation reduces elastohydrodynamic film thickness and increases surface temperatures. Methods are presented which allow for the application of elastohydrodynamic principles to transmission design in order to increase system life and reliability.
Elastohydrodynamic principles applied to the design of helicopter components
NASA Technical Reports Server (NTRS)
Townsend, D. P.
1973-01-01
Elastohydrodynamic principles affecting the lubrication of transmission components are presented and discussed. Surface temperature of the transmission bearings and gears affect elastohydrodynamic film thickness. Traction forces and sliding as well as the inlet temperature determine surface temperatures. High contact ratio gears cause increased sliding and may run at higher surface temperatures. Component life is a function of the ratio of elastohydrodynamic film thickness to composite surface roughness. Lubricant starvation reduces elastrohydrodynamic film thickness and increases surface temperatures. Methods are presented which allow for the application of elastohydrodynamic principles to transmission design in order to increase system life and reliability.
Life Support System Technologies for NASA Exploration Missions
NASA Technical Reports Server (NTRS)
Ewert, Michael K.
2007-01-01
The Lunar Mars Life Support Test series successfully demonstrated integration and operation of advanced technologies for closed-loop life support systems, including physicochemical and biological subsystems. Increased closure was obtained when targeted technologies, such as brine dewatering subsystems, were added to further process life support system byproducts to recover resources. Physicochemical and biological systems can be integrated satisfactorily to achieve desired levels of closure. Imbalances between system components, such as differences in metabolic quotients between human crews and plants, must be addressed. Each subsystem or component that is added to increase closure will likely have added costs, ranging from initial launch mass, power, thermal, crew time, byproducts, etc., that must be factored into break even analysis. Achieving life support system closure while maintaining control of total mass and system complexity will be a challenge.
2011-01-01
Background Ontologies are increasingly used to structure and semantically describe entities of domains, such as genes and proteins in life sciences. Their increasing size and the high frequency of updates resulting in a large set of ontology versions necessitates efficient management and analysis of this data. Results We present GOMMA, a generic infrastructure for managing and analyzing life science ontologies and their evolution. GOMMA utilizes a generic repository to uniformly and efficiently manage ontology versions and different kinds of mappings. Furthermore, it provides components for ontology matching, and determining evolutionary ontology changes. These components are used by analysis tools, such as the Ontology Evolution Explorer (OnEX) and the detection of unstable ontology regions. We introduce the component-based infrastructure and show analysis results for selected components and life science applications. GOMMA is available at http://dbs.uni-leipzig.de/GOMMA. Conclusions GOMMA provides a comprehensive and scalable infrastructure to manage large life science ontologies and analyze their evolution. Key functions include a generic storage of ontology versions and mappings, support for ontology matching and determining ontology changes. The supported features for analyzing ontology changes are helpful to assess their impact on ontology-dependent applications such as for term enrichment. GOMMA complements OnEX by providing functionalities to manage various versions of mappings between two ontologies and allows combining different match approaches. PMID:21914205
Ratcheting fatigue behavior of Zircaloy-2 at room temperature
NASA Astrophysics Data System (ADS)
Rajpurohit, R. S.; Sudhakar Rao, G.; Chattopadhyay, K.; Santhi Srinivas, N. C.; Singh, Vakil
2016-08-01
Nuclear core components of zirconium alloys experience asymmetric stress or strain cycling during service which leads to plastic strain accumulation and drastic reduction in fatigue life as well as dimensional instability of the component. Variables like loading rate, mean stress, and stress amplitude affect the influence of asymmetric loading. In the present investigation asymmetric stress controlled fatigue tests were conducted with mean stress from 80 to 150 MPa, stress amplitude from 270 to 340 MPa and stress rate from 30 to 750 MPa/s to study the process of plastic strain accumulation and its effect on fatigue life of Zircaloy-2 at room temperature. It was observed that with increase in mean stress and stress amplitude accumulation of ratcheting strain was increased and fatigue life was reduced. However, increase in stress rate led to improvement in fatigue life due to less accumulation of ratcheting strain.
[Physical and mental dimensions of quality of life of frail older people].
Gobbens, Robbert J J
2017-09-01
Frail older people have an increased risk of limitations in performing activities of daily living, hospitalization, nursing home admission, and premature death. In this study we determined the difference in experiencing quality of life between frail and non-frail older people. We also investigated the associations between physical, psychological and social components of frailty and the physical and mental dimensions of quality of life. 374 people of 75 years and older filled in a questionnaire, the Senioren Barometer. This questionnaire contained the Tilburg Frailty Indicator (TFI) to assess frailty and the SF-12 for assessing quality of life. The study showed that frail older people on average experience a lower quality of life than non-frail older people. A considerable part of the variance of the physical and mental dimensions of quality of life could be explained by the fifteen components of frailty, after controlling for the background characteristics of the respondents, 33.2% and 36.5%, respectively. The frailty components physical inactivity, physical tiredness, and depressive symptoms were associated with the physical dimension as well as the mental dimension of quality of life. The results confirm the importance of multidimensional assessment of frailty. In addition, they provide a direction to healthcare and welfare professionals in performing interventions with the aim of increasing the quality of life of older people.
Long-term strategies for increased recycling of automotive aluminum and its alloying elements.
Løvik, Amund N; Modaresi, Roja; Müller, Daniel B
2014-04-15
Aluminum recycling currently occurs in a cascading fashion, where some alloys, used in a limited number of applications, absorb most of the end-of-life scrap. An expected increase in scrap supply in coming decades necessitates restructuring of the aluminum cycle to open up new recycling paths for alloys and avoid a potential scrap surplus. This paper explores various interventions in end-of-life management and recycling of automotive aluminum, using a dynamic substance flow analysis model of aluminum and its alloying elements with resolution on component and alloy level (vehicle-component-alloy-element model). It was found that increased component dismantling before vehicle shredding can be an effective, so far underestimated, intervention in the medium term, especially if combined with development of safety-relevant components such as wheels from secondary material. In the long term, automatic alloy sorting technologies are most likely required, but could at the same time reduce the need for magnesium removal in refining. Cooperation between the primary and secondary aluminum industries, the automotive industry, and end-of-life vehicle dismantlers is therefore essential to ensure continued recycling of automotive aluminum and its alloying elements.
Silva, Graciela E.; An, Ming-Wen; Goodwin, James L.; Shahar, Eyal; Redline, Susan; Resnick, Helaine; Baldwin, Carol M.; Quan, Stuart F.
2009-01-01
Study Objectives: Findings from population studies evaluating the progression and incidence of sleep disordered breathing have shown evidence of a longitudinal increase in the severity of sleep disordered breathing. The present study evaluates the association among changes in sleep disordered breathing, sleep symptoms, and quality of life over time. Design: Prospective cohort study. Data were from the Sleep Heart Health Study. Setting: Multicenter study. Participants: Three thousand seventy-eight subjects aged 40 years and older from the baseline and follow-up examination cycles were included. Measurements: The primary outcomes were changes in the Physical Component Summary and Mental Component Summary scales obtained from the Medical Outcomes Study Short-Form Health Survey. The primary exposure was change in the respiratory disturbance index obtained from unattended overnight polysomnograms performed approximately 5 years apart. Other covariates included measures of excessive daytime sleepiness and difficulty initiating and maintaining sleep. Results: Mean respiratory disturbance index increased from 8.1 ± 11 SD at baseline to 10.9 ± 14 (P < 0.0001) at follow-up. The mean Physical Component Summary and Mental Component Summary scores were 48.5 and 54.1 at baseline and 46.3 and 54.8 at follow-up. No associations between change in respiratory disturbance index and changes in Physical Component Summary or Mental Component Summary scores were seen. However, worsening of difficulty initiating and maintaining sleep and excessive daytime sleepiness were significantly associated with lower quality of life. Conclusions: A slight increase in severity of sleep disordered breathing was seen over 5 years; this was not associated with worsening of quality of life. However, subjective symptoms of quality of sleep and daytime sleepiness were associated with declining quality of life. Citation: Silva GE; An MW; Goodwin JL; Shahar E; Redline S; Resnick H; Baldwin CM; Quan SF. Longitudinal evaluation of sleep-disordered breathing and sleep symptoms with change in quality of life: the Sleep Heart Health Study (SHHS). SLEEP 2009;32(8):1049-1057. PMID:19725256
Kronish, Ian M; Carson, April P; Davidson, Karina W; Muntner, Paul; Safford, Monika M
2012-01-01
Depressive symptoms are associated with increased incident and recurrent cardiovascular events. In 2010, the American Heart Association published the Life's Simple 7, a metric for assessing cardiovascular health as measured by 4 health behaviors (smoking, physical activity, body mass index, diet) and 3 biological measures (cholesterol, blood pressure, glucose). The association between depressive symptoms and the Life's Simple 7 has not yet been explored. Data from 20,093 participants ≥45 years of age who enrolled in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study between 2003 and 2007 and who had complete data available on Life's Simple 7 components were used for these analyses. The prevalence of ideal, intermediate, and poor health on each Life's Simple 7 component and total Life's Simple 7 scores were compared between participants with and without depressive symptoms. Depressive symptoms were measured using the 4-item Centers for Epidemiologic Studies of Depression scale. Participants with depressive symptoms were more likely to have poor levels on each of the Life's Simple 7 components other than cholesterol [adjusted prevalence ratios (95% CI): smoking 1.41 (1.29-1.55); physical activity 1.38 (1.31-1.46); body mass index 1.09 (1.04-1.15); diet 1.08 (1.06-1.10); blood pressure 1.11 (1.02-1.21); glucose 1.24 (1.09-1.41)]. There was a graded association between increasing depressive symptoms and lower total Life's Simple 7 score. Depressive symptoms are associated with worse cardiovascular health on the overall Life's Simple 7 and on individual components representing both health behaviors and biological factors.
A Statistical Simulation Approach to Safe Life Fatigue Analysis of Redundant Metallic Components
NASA Technical Reports Server (NTRS)
Matthews, William T.; Neal, Donald M.
1997-01-01
This paper introduces a dual active load path fail-safe fatigue design concept analyzed by Monte Carlo simulation. The concept utilizes the inherent fatigue life differences between selected pairs of components for an active dual path system, enhanced by a stress level bias in one component. The design is applied to a baseline design; a safe life fatigue problem studied in an American Helicopter Society (AHS) round robin. The dual active path design is compared with a two-element standby fail-safe system and the baseline design for life at specified reliability levels and weight. The sensitivity of life estimates for both the baseline and fail-safe designs was examined by considering normal and Weibull distribution laws and coefficient of variation levels. Results showed that the biased dual path system lifetimes, for both the first element failure and residual life, were much greater than for standby systems. The sensitivity of the residual life-weight relationship was not excessive at reliability levels up to R = 0.9999 and the weight penalty was small. The sensitivity of life estimates increases dramatically at higher reliability levels.
40 CFR 1033.645 - Non-OEM component certification program.
Code of Federal Regulations, 2010 CFR
2010-07-01
... needs of your component. (iv) An engineering analysis (including test data in some cases) demonstrating to us that your component will not cause emissions to increase. The analysis must address both low-hour and end-of-useful life emissions. The amount of information required for this analysis is less...
40 CFR 1033.645 - Non-OEM component certification program.
Code of Federal Regulations, 2011 CFR
2011-07-01
... needs of your component. (iv) An engineering analysis (including test data in some cases) demonstrating to us that your component will not cause emissions to increase. The analysis must address both low-hour and end-of-useful life emissions. The amount of information required for this analysis is less...
Analysis of the Environmental Impact on Remanufacturing Wind Turbines
NASA Astrophysics Data System (ADS)
Sosa Skrainka, Manuel R.
To deliver clean energy the use of wind turbines is essential. In June 2011 there was an installed wind capacity equivalent to 211,000MW world-wide (WWEA, 2011). By the end of the year 2009 the U.S. had 35,100MW of wind energy installed capacity to generate electricity (AWEA, 2010). This industry has grown in recent years and is expected to grow even more in the future. The environmental impacts that will arise from the increased number of wind turbines and their end-of-life should be addressed, as large amounts of resources will be required to satisfy the current and future market demands for wind turbines. Since future 10MW wind turbines are expected to be as heavy as 1000 tons each, the study of the environmental response of profitable retirement strategies, such as remanufacturing for these machines, must be considered. Because of the increased number of wind turbines and the materials used, this study provides a comparison between the environmental impacts from remanufacturing the components installed inside the nacelle of multi-megawatt wind turbines and wind turbines manufactured using new components. The study methodology is the following: • Describe the life-cycle and the materials and processes employed for the manufacture and remanufacturing for components inside the nacelle. • Identify remanufacturing alternatives for the components inside the nacelle at the end of the expected life-time service of wind turbines. • Evaluate the environmental impacts from the remanufactured components and compare the results with the impacts of the manufacturing of new components using SimaPro. • Conduct sensitivity analysis over the critical parameters of the life cycle assessment • Propose the most environmentally friendly options for the retirement of each major component of wind turbines. After an analysis of the scenarios the goal of the study is to evaluate remanufacturing as an end-of-life option from an environmental perspective for commercial multi-megawatt wind turbines targeted for secondary wind turbine markets.
Sanchez-Aguadero, Natalia; Alonso-Dominguez, Rosario; Garcia-Ortiz, Luis; Agudo-Conde, Cristina; Rodriguez-Martin, Carmela; de Cabo-Laso, Angela; Sanchez-Salgado, Benigna; Ramos, Rafel; Maderuelo-Fernandez, Jose A; Gomez-Marcos, Manuel A; Recio-Rodriguez, Jose I
2016-12-07
To analyze the interplay between diet, physical activity and health-related quality of life in a Spanish randomly selected sample of individuals attended in general practitioners offices with intermediate cardiovascular risk. This study analyzed 314 subjects, aged 35-74 years (50.6% women), from the MARK study, conducted in Spain. Health related quality of life was measured by the SF-12 questionnaire. The assessment of the lifestyles included the diet quality index, the adherence to the Mediterranean diet and the leisure time physical activity practice. The highest values of health related quality of life were obtained in the area of vitality (51.05 ± 11.13), while the lowest were found in the general health (39.89 ± 8.85). In the multiple linear regression analysis, after adjustment for age, gender and other confounders, for each point of increase in the Mediterranean diet adherence score, there was an increase of 1.177 points in the mental component value (p < 0.01). Similarly, for each point of increase in the Diet Quality Index Score, there was an increase in the mental component of 0.553 (p < 0.05). Likewise, the physical activity was positively associated with the physical function and vitality (β = 0.090 and 0.087, (p < 0.01 and p < 0.05), respectively). In people with intermediate cardiovascular risk, better food habits and greater adherence to the Mediterranean diet are associated with higher scores on the mental component of quality of life. Likewise, increased physical activity is related with positive scores on the physical function.
Menon, Jyothi; Paulet, Mindy; Thomas, Joseph
2012-10-01
Association between wellness coaching and changes in health-related quality of life over 1 year and 2 years was assessed. Difference-in-differences analysis of covariance assessed association between coaching and change in 8-item short-form health survey (SF-8) summary scores. Ordered logistic models assessed coaching and change in SF-8 individual domain scores. This was a case-control study. Participants in at least one coaching program were more likely to have increases in social functioning after 1 year and less likely to have increases in role physical after 2 years. Participants in nutrition coaching had more positive change in mental component summary scores after 1 year. Participants in stress management had more negative change in mental component summary scores after 1 year and after 2 years and had more negative change in physical component summary scores after 2 years. Findings were mixed regarding association between coaching and change in health-related quality of life.
The evolution of complex life cycles when parasite mortality is size- or time-dependent.
Ball, M A; Parker, G A; Chubb, J C
2008-07-07
In complex cycles, helminth larvae in their intermediate hosts typically grow to a fixed size. We define this cessation of growth before transmission to the next host as growth arrest at larval maturity (GALM). Where the larval parasite controls its own growth in the intermediate host, in order that growth eventually arrests, some form of size- or time-dependent increase in its death rate must apply. In contrast, the switch from growth to sexual reproduction in the definitive host can be regulated by constant (time-independent) mortality as in standard life history theory. We here develop a step-wise model for the evolution of complex helminth life cycles through trophic transmission, based on the approach of Parker et al. [2003a. Evolution of complex life cycles in helminth parasites. Nature London 425, 480-484], but which includes size- or time-dependent increase in mortality rate. We assume that the growing larval parasite has two components to its death rate: (i) a constant, size- or time-independent component, and (ii) a component that increases with size or time in the intermediate host. When growth stops at larval maturity, there is a discontinuous change in mortality to a constant (time-independent) rate. This model generates the same optimal size for the parasite larva at GALM in the intermediate host whether the evolutionary approach to the complex life cycle is by adding a new host above the original definitive host (upward incorporation), or below the original definitive host (downward incorporation). We discuss some unexplored problems for cases where complex life cycles evolve through trophic transmission.
Second Life as a Surrogate for Experiential Learning
ERIC Educational Resources Information Center
DeMers, Michael N.
2010-01-01
Second Life is increasingly being used as a venue for education, especially for delivery of online instruction where social presence and community building are essential components. Despite its robust 3-D modeling tools and powerful scripting language, many educational uses of Second Life are limited to passive forms of content delivery that often…
Transient Reliability Analysis Capability Developed for CARES/Life
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.
2001-01-01
The CARES/Life software developed at the NASA Glenn Research Center provides a general-purpose design tool that predicts the probability of the failure of a ceramic component as a function of its time in service. This award-winning software has been widely used by U.S. industry to establish the reliability and life of a brittle material (e.g., ceramic, intermetallic, and graphite) structures in a wide variety of 21st century applications.Present capabilities of the NASA CARES/Life code include probabilistic life prediction of ceramic components subjected to fast fracture, slow crack growth (stress corrosion), and cyclic fatigue failure modes. Currently, this code can compute the time-dependent reliability of ceramic structures subjected to simple time-dependent loading. For example, in slow crack growth failure conditions CARES/Life can handle sustained and linearly increasing time-dependent loads, whereas in cyclic fatigue applications various types of repetitive constant-amplitude loads can be accounted for. However, in real applications applied loads are rarely that simple but vary with time in more complex ways such as engine startup, shutdown, and dynamic and vibrational loads. In addition, when a given component is subjected to transient environmental and or thermal conditions, the material properties also vary with time. A methodology has now been developed to allow the CARES/Life computer code to perform reliability analysis of ceramic components undergoing transient thermal and mechanical loading. This means that CARES/Life will be able to analyze finite element models of ceramic components that simulate dynamic engine operating conditions. The methodology developed is generalized to account for material property variation (on strength distribution and fatigue) as a function of temperature. This allows CARES/Life to analyze components undergoing rapid temperature change in other words, components undergoing thermal shock. In addition, the capability has been developed to perform reliability analysis for components that undergo proof testing involving transient loads. This methodology was developed for environmentally assisted crack growth (crack growth as a function of time and loading), but it will be extended to account for cyclic fatigue (crack growth as a function of load cycles) as well.
Christian, Erica J; Meltzer, Christine L; Thede, Linda L; Kosson, David S
2017-04-01
Despite increasing interest in understanding psychopathic traits in youth, the role of early environmental factors in the development of psychopathic traits is not well understood. No prior studies have directly examined the relationship between early life events and psychopathic traits. We examined links between life events in the first 4 years of life and indices of the core affective and interpersonal components of psychopathy. Additionally, we examined relationships between early life events, psychopathic traits, and attachment to parents among 206 adjudicated adolescents. Results indicated that the total number of early life events was positively correlated with indices of the affective component of psychopathy. Moreover, psychopathic traits moderated the relationship between the number of early life events and later reports of attachment to parents. Findings suggest that early environmental factors could have important implications for the development of psychopathic traits and may impact attachment to parents for youth with psychopathic traits.
Defining quality of nursing work life.
Brooks, Beth A; Anderson, Mary Ann
2005-01-01
As the largest single employee component of hospitals, nurses are critical to the functioning of the organization, and improving employee productivity continues to be a common theme in the health care literature. However, any increased productivity will be transitory if achieved at the expense of the quality of nurses' work life (QNWL), since improvement in the QNWL is prerequisite to improved productivity. The conceptual components of the concept of QNWL that differentiate QNWL from the concept job satisfaction are explored.
Franklin, Rebecca A; Butler, Michael P; Bentley, Jacob A
2018-08-01
Yoga contains sub-components related to its physical postures (asana), breathing methods (pranayama), and meditation (dhyana). To test the hypothesis that specific yoga practices are associated with reduced psychological distress, 186 adults completed questionnaires assessing life stressors, symptom severity, and experience with each of these aspects of yoga. Each yoga sub-component was found to be negatively correlated with psychological distress indices. However, differing patterns of relationship to psychological distress symptoms were found for each yoga sub-component. Experience with asana was negatively correlated with global psychological distress (r = -.21, p < .01), and symptoms of anxiety (r = -.18, p = .01) and depression (r = -.17, p = .02). These relationships remained statistically significant after accounting for variance attributable to Social Readjustment Rating Scale scores (GSI: r = -.19, p = .01; BSI Anxiety: r = -.16, p = .04; BSI Depression: r = -.14, p = .05). By contrast, the correlations between other yoga sub-components and symptom subscales became non-significant after accounting for exposure to life stressors. Moreover, stressful life events moderated the predictive relationship between amount of asana experience and depressive symptoms. Asana was not related to depressive symptoms at low levels of life stressors, but became associated at mean (t[182] = -2.73, p < .01) and high levels (t[182] = -3.56, p < .001). Findings suggest asana may possess depressive symptom reduction benefits, particularly as life stressors increase. Additional research is needed to differentiate whether asana has an effect on psychological distress, and to better understand potential psychophysiological mechanisms of action.
NASA Technical Reports Server (NTRS)
Johnson, Michael R.; Gehling, Russ; Head, Ray
2006-01-01
This paper will present a process for increasing the stiffness of harmonic gear assemblies and recommend a maximum stiffness point that, if exceeded, compromises the reliability of the gear components for long life applications.
Ward, M.E.; Harkins, B.D.
1993-11-30
Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.
Ward, Michael E.; Harkins, Bruce D.
1993-01-01
Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.
Mjørud, Marit; Kirkevold, Marit; Røsvik, Janne; Engedal, Knut
2014-01-01
To investigate which factors the Quality of Life in Late-Stage Dementia (QUALID) scale holds when used among people with dementia (pwd) in nursing homes and to find out how the symptom load varies across the different severity levels of dementia. We included 661 pwd [mean age ± SD, 85.3 ± 8.6 years; 71.4% women]. The QUALID and the Clinical Dementia Rating (CDR) scale were applied. A principal component analysis (PCA) with varimax rotation and Kaiser normalization was applied to test the factor structure. Nonparametric analyses were applied to examine differences of symptom load across the three CDR groups. The mean QUALID score was 21.5 (±7.1), and the CDR scores of the three groups were 1 in 22.5%, 2 in 33.6% and 3 in 43.9%. The results of the statistical measures employed were the following: Crohnbach's α of QUALID, 0.74; Bartlett's test of sphericity, p <0.001; the Kaiser-Meyer-Olkin measure, 0.77. The PCA analysis resulted in three components accounting for 53% of the variance. The first component was 'tension' ('facial expression of discomfort', 'appears physically uncomfortable', 'verbalization suggests discomfort', 'being irritable and aggressive', 'appears calm', Crohnbach's α = 0.69), the second was 'well-being' ('smiles', 'enjoys eating', 'enjoys touching/being touched', 'enjoys social interaction', Crohnbach's α = 0.62) and the third was 'sadness' ('appears sad', 'cries', 'facial expression of discomfort', Crohnbach's α 0.65). The mean score on the components 'tension' and 'well-being' increased significantly with increasing severity levels of dementia. Three components of quality of life (qol) were identified. Qol decreased with increasing severity of dementia. © 2013 S. Karger AG, Basel.
Ucan, Ozlem; Ovayolu, Nimet
2010-09-01
The main goal of nursing care should be to increase health-related quality of life as well as improve the medical status of patients with chronic disease. For this reason, this study aims to evaluate and compare the health-related quality of life of patients with diabetes mellitus, hypertension and obesity in Gaziantep, a south-eastern city in Turkey. Diabetes mellitus, hypertension and obesity are the most decisive factors in terms of adversely affecting health-related quality of life. A cross-sectional, descriptive design was used. In this study, the research population included a total of 1601 diabetes mellitus, hypertension and obesity patients. To evaluate health-related quality of life of patients, Short Form-36 (SF-36) was used. Student's t-test, one-way anova and chi-square analyses were used for comparisons between groups. In total, 18·1% of patients had combined obesity, hypertension and diabetes mellitus; 16·1% had hypertension and diabetes mellitus. Approximately 16·1% had only hypertension; 15·4% had obesity and hypertension; 13·3% had diabetes mellitus; 12·7% had obesity and diabetes mellitus; and 8·4% had obesity. The health-related quality of life physical component mean scores of patients with combined obesity and hypertension were lower than that of the other groups (p < 0·05). Health-related quality of life physical component mean scores were determined as 34·5 (SD 0·4), and mental component mean scores were determined as 43·9 (SD 4·4). Health-related quality of life physical component mean scores of moderately active patients were higher, while older age and lower educational and income levels had a negative effect on health-related quality of life (p < 0·05). Diabetes, hypertension and obesity decrease patient health-related quality of life while physical activity increases it. The coexistence of obesity and hypertension, in particular, has a more negative effect on health-related quality of life. Patients with hypertension, obesity and diabetes mellitus need professional support from nurse. Frequent health-related quality of life evaluation and support is required for chronic patients, especially for those who are older, have lower educational and income levels and those with more than one chronic disease. © 2010 Blackwell Publishing Ltd.
Tsai, Hung-Bin; Chao, Chia-Ter; Chang, Ray-E; Hung, Kuan-Yu; COGENT Study Group
2017-06-26
Few studies have addressed health-related quality of life (QoL) in patients who chose conservative management over dialysis. This systematic review aims to better define the role of conservative management in improving health-related QoL in patients with end-stage renal disease (ESRD). Medline, Cochrane and EMBASE were searched for prospective or retrospective studies published until June 30, 2016, that examined QoL of ESRD patients. The primary outcome was health-related QoL. Four studies were included (405 patients received dialysis and 332 received conservative management). Two studies that used the Short Form-36 Survey (SF-36) showed that the dialysis group had higher physical component scores, but the conservative management group had similar, or better, mental component scores at the end of intervention. Another study using the SF-36 showed that the physical and mental component scores of the dialysis group did not significantly change after intervention. In the conservative management group, the physical component scores did not change, but the mental component scores increased significantly over time (0.12 ± 0.32, p < 0.05). One study, which used the Kidney Disease Quality of Life-Short Form (KD QoL-SF), found no change after intervention in either physical or mental component scores in the dialysis group; however, the physical component score declined (p = 0.047) and the mental component score increased (p = 0.033) in the conservative management group. Although there are only a limited number of published articles, ESRD patients who receive conservative management may have improved mental health-related QoL when compared with those who receive dialysis.
Chemical Composition of Fine Particulate Matter and Life Expectancy
Dominici, Francesca; Wang, Yun; Correia, Andrew W.; Ezzati, Majid; Pope, C. Arden; Dockery, Douglas W.
2016-01-01
Background In a previous study, we provided evidence that a decline in fine particulate matter (PM2.5) air pollution during the period between 2000 and 2007 was associated with increased life expectancy in 545 counties in the United States. In this article, we investigated which chemical constituents of PM2.5 were the main drivers of the observed association. Methods We estimated associations between temporal changes in seven major components of PM2.5 (ammonium, sulfate, nitrate, elemental carbon matter, organic carbon matter, sodium, and silicon) and temporal changes in life expectancy in 95 counties between 2002 and 2007. We included US counties that had adequate chemical components of PM2.5 mass data across all seasons. We fitted single pollutant and multiple pollutant linear models, controlling for available socioeconomic, demographic, and smoking variables and stratifying by urban and nonurban counties. Results In multiple pollutant models, we found that: (1) a reduction in sulfate was associated with an increase in life expectancy; and (2) reductions in ammonium and sodium ion were associated with increases in life expectancy in nonurban counties only. Conclusions Our findings suggest that recent reductions in long-term exposure to sulfate, ammonium, and sodium ion between 2002 and 2007 are associated with improved public health. PMID:25906366
Dominici, Francesca; Wang, Yun; Correia, Andrew W; Ezzati, Majid; Pope, C Arden; Dockery, Douglas W
2015-07-01
In a previous study, we provided evidence that a decline in fine particulate matter (PM2.5) air pollution during the period between 2000 and 2007 was associated with increased life expectancy in 545 counties in the United States. In this article, we investigated which chemical constituents of PM2.5 were the main drivers of the observed association. We estimated associations between temporal changes in seven major components of PM2.5 (ammonium, sulfate, nitrate, elemental carbon matter, organic carbon matter, sodium, and silicon) and temporal changes in life expectancy in 95 counties between 2002 and 2007. We included US counties that had adequate chemical components of PM2.5 mass data across all seasons. We fitted single pollutant and multiple pollutant linear models, controlling for available socioeconomic, demographic, and smoking variables and stratifying by urban and nonurban counties. In multiple pollutant models, we found that: (1) a reduction in sulfate was associated with an increase in life expectancy; and (2) reductions in ammonium and sodium ion were associated with increases in life expectancy in nonurban counties only. Our findings suggest that recent reductions in long-term exposure to sulfate, ammonium, and sodium ion between 2002 and 2007 are associated with improved public health.
NASA Technical Reports Server (NTRS)
Fatig, Michael
1993-01-01
Flight operations and the preparation for it has become increasingly complex as mission complexities increase. Further, the mission model dictates that a significant increase in flight operations activities is upon us. Finally, there is a need for process improvement and economy in the operations arena. It is therefore time that we recognize flight operations as a complex process requiring a defined, structured, and life cycle approach vitally linked to space segment, ground segment, and science operations processes. With this recognition, an FOT Tool Kit consisting of six major components designed to provide tools to guide flight operations activities throughout the mission life cycle was developed. The major components of the FOT Tool Kit and the concepts behind the flight operations life cycle process as developed at NASA's GSFC for GSFC-based missions are addressed. The Tool Kit is therefore intended to increase productivity, quality, cost, and schedule performance of the flight operations tasks through the use of documented, structured methodologies; knowledge of past lessons learned and upcoming new technology; and through reuse and sharing of key products and special application programs made possible through the development of standardized key products and special program directories.
High pressure ceramic heat exchanger
Harkins, Bruce D.; Ward, Michael E.
1998-01-01
Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a strengthening reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the strengthening reinforcing member. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.
High pressure ceramic heat exchanger
Harkins, Bruce D.; Ward, Michael E.
1999-01-01
Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the reinforcing member and having a strengthening member wrapped around the refractory material. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.
High pressure ceramic heat exchanger
Harkins, B.D.; Ward, M.E.
1998-09-22
Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a strengthening reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the strengthening reinforcing member. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 5 figs.
Microgreens: Production, shelf life, and bioactive components.
Mir, Shabir Ahmad; Shah, Manzoor Ahmad; Mir, Mohammad Maqbool
2017-08-13
Microgreens are emerging specialty food products which are gaining popularity and increased attention nowadays. They are young and tender cotyledonary leafy greens that are found in a pleasing palette of colors, textures, and flavors. Microgreens are a new class of edible vegetables harvested when first leaves have fully expanded and before true leaves have emerged. They are gaining popularity as a new culinary ingredient. They are used to enhance salads or as edible garnishes to embellish a wide variety of other dishes. Common microgreens are grown mainly from mustard, cabbage, radish, buckwheat, lettuce, spinach, etc. The consumption of microgreens has nowadays increased due to higher concentrations of bioactive components such as vitamins, minerals, and antioxidants than mature greens, which are important for human health. However, they typically have a short shelf life due to rapid product deterioration. This review aimed to evaluate the postharvest quality, potential bioactive compounds, and shelf life of microgreens for proper management of this specialty produce.
A methodology for probabilistic remaining creep life assessment of gas turbine components
NASA Astrophysics Data System (ADS)
Liu, Zhimin
Certain gas turbine components operate in harsh environments and various mechanisms may lead to component failure. It is common practice to use remaining life assessments to help operators schedule maintenance and component replacements. Creep is a major failure mechanisms that affect the remaining life assessment, and the resulting life consumption of a component is highly sensitive to variations in the material stresses and temperatures, which fluctuate significantly due to the changes in real operating conditions. In addition, variations in material properties and geometry will result in changes in creep life consumption rate. The traditional method used for remaining life assessment assumes a set of fixed operating conditions at all times, and it fails to capture the variations in operating conditions. This translates into a significant loss of accuracy and unnecessary high maintenance and replacement cost. A new method that captures these variations described above and improves the prediction accuracy of remaining life is developed. First, a metamodel is built to approximate the relationship between variables (operating conditions, material properties, geometry, etc.) and a creep response. The metamodel is developed using Response Surface Method/Design of Experiments methodology. Design of Experiments is an efficient sampling method, and for each sampling point a set of finite element analyses are used to compute the corresponding response value. Next, a low order polynomial Response Surface Equation (RSE) is used to fit these values. Four techniques are suggested to dramatically reduce computational effort, and to increase the accuracy of the RSE: smart meshing technique, automatic geometry parameterization, screening test and regional RSE refinement. The RSEs, along with a probabilistic method and a life fraction model are used to compute current damage accumulation and remaining life. By capturing the variations mentioned above, the new method results in much better accuracy than that available using the traditional method. After further development and proper verification the method should bring significant savings by reducing the number of inspections and deferring part replacement.
ERIC Educational Resources Information Center
Peterson, Christina Hamme
2012-01-01
Counseling work is increasingly conducted in team format. The methods counseling teams use to manage the emotional component of their group life, or their group emotional intelligence, have been proposed as significantly contributing to group member trust, cooperation, and ultimate performance. Item development, exploratory factor analysis, and…
Service Life Extension of the Propulsion System of Long-Term Manned Orbital Stations
NASA Technical Reports Server (NTRS)
Kamath, Ulhas; Kuznetsov, Sergei; Spencer, Victor
2014-01-01
One of the critical non-replaceable systems of a long-term manned orbital station is the propulsion system. Since the propulsion system operates beginning with the launch of station elements into orbit, its service life determines the service life of the station overall. Weighing almost a million pounds, the International Space Station (ISS) is about four times as large as the Russian space station Mir and about five times as large as the U.S. Skylab. Constructed over a span of more than a decade with the help of over 100 space flights, elements and modules of the ISS provide more research space than any spacecraft ever built. Originally envisaged for a service life of fifteen years, this Earth orbiting laboratory has been in orbit since 1998. Some elements that have been launched later in the assembly sequence were not yet built when the first elements were placed in orbit. Hence, some of the early modules that were launched at the inception of the program were already nearing the end of their design life when the ISS was finally ready and operational. To maximize the return on global investments on ISS, it is essential for the valuable research on ISS to continue as long as the station can be sustained safely in orbit. This paper describes the work performed to extend the service life of the ISS propulsion system. A system comprises of many components with varying failure rates. Reliability of a system is the probability that it will perform its intended function under encountered operating conditions, for a specified period of time. As we are interested in finding out how reliable a system would be in the future, reliability expressed as a function of time provides valuable insight. In a hypothetical bathtub shaped failure rate curve, the failure rate, defined as the number of failures per unit time that a currently healthy component will suffer in a given future time interval, decreases during infant-mortality period, stays nearly constant during the service life and increases at the end when the design service life ends and wear-out phase begins. However, the component failure rates do not remain constant over the entire cycle life. The failure rate depends on various factors such as design complexity, current age of the component, operating conditions, severity of environmental stress factors, etc. Development, qualification and acceptance test processes provide rigorous screening of components to weed out imperfections that might otherwise cause infant mortality failures. If sufficient samples are tested to failure, the failure time versus failure quantity can be analyzed statistically to develop a failure probability distribution function (PDF), a statistical model of the probability of failure versus time. Driven by cost and schedule constraints however, spacecraft components are generally not tested in large numbers. Uncertainties in failure rate and remaining life estimates increase when fewer units are tested. To account for this, spacecraft operators prefer to limit useful operations to a period shorter than the maximum demonstrated service life of the weakest component. Running each component to its failure to determine the maximum possible service life of a system can become overly expensive and impractical. Spacecraft operators therefore, specify the required service life and an acceptable factor of safety (FOS). The designers use these requirements to limit the life test duration. Midway through the design life, when benefits justify additional investments, supplementary life test may be performed to demonstrate the capability to safely extend the service life of the system. An innovative approach is required to evaluate the entire system, without having to go through an elaborate test program of propulsion system elements. Evaluating every component through a brute force test program would be a cost prohibitive and time consuming endeavor. ISS propulsion system components were designed and built decades ago. There are no representative ground test articles for some of the components. A 'test everything' approach would require manufacturing new test articles. The paper outlines some of the techniques used for selective testing, by way of cherry picking candidate components based on failure mode effects analysis, system level impacts, hazard analysis, etc. The type of testing required for extending the service life depends on the design and criticality of the component, failure modes and failure mechanisms, life cycle margin provided by the original certification, operational and environmental stresses encountered, etc. When specific failure mechanism being considered and the underlying relationship of that mode to the stresses provided in the test can be correlated by supporting analysis, time and effort required for conducting life extension testing can be significantly reduced. Exposure to corrosive propellants over long periods of time, for instance, lead to specific failure mechanisms in several components used in the propulsion system. Using Arrhenius model, which is tied to chemically dependent failure mechanisms such as corrosion or chemical reactions, it is possible to subject carefully selected test articles to accelerated life test. Arrhenius model reflects the proportional relationship between time to failure of a component and the exponential of the inverse of absolute temperature acting on the component. The acceleration factor is used to perform tests at higher stresses that allow direct correlation between the times to failure at a high test temperature to the temperatures to be expected in actual use. As long as the temperatures are such that new failure mechanisms are not introduced, this becomes a very useful method for testing to failure a relatively small sample of items for a much shorter amount of time. In this article, based on the example of the propulsion system of the first ISS module Zarya, theoretical approaches and practical activities of extending the service life of the propulsion system are reviewed with the goal of determining the maximum duration of its safe operation.
NASA Astrophysics Data System (ADS)
Jørgensen, Christian; Holt, Rebecca E.
2013-01-01
A stronger focus on natural mortality may be required to better understand contemporary changes in fish life histories and behaviour and their responses to anthropogenic drivers. Firstly, natural mortality is the selection under which fish evolved in the first place, so a theoretical understanding of effects of natural mortality alone is needed. Secondly, due to trade-offs, most organismal functions can only be achieved at some cost in terms of survival. Several trade-offs might need to be analysed simultaneously with effects on natural mortality being a common currency. Thirdly, there is scattered evidence that natural mortality has been increasing, some would say dramatically, in some fished stocks, which begs explanations. Fourthly, natural mortality most often implies transfer of mass and energy from one species to another, and therefore has foodweb and ecosystem consequences. We therefore analyse a model for evolution of fish life histories and behaviour, where state-dependent energy-allocation and growth strategies are found by optimization. Natural mortality is split into five different components, each specified as the outcome of individual traits and ecological trade-offs: a fixed baseline mortality; size-dependent predation; risk-dependent growth strategy; a fixed mortality when sexually mature; and mortality increasing with reproductive investment. The analysis is repeated with and without fishing. Each component of natural mortality has consequences for optimal life history strategies. Beyond earlier models, we show i) how the two types of reproductive mortality sometimes have similar and sometimes contrasting effects on life history evolution, ii) how ecosystem properties such as food availability and predation levels have stronger effects on optimal strategies than changing other mortality components, and iii) how expected changes in risk-dependent growth strategies are highly variable depending on the type of mortality changed.
Effect of weight reduction on quality of life and eating behaviors in obese women.
Lemoine, Sophie; Rossell, Nadia; Drapeau, Vicky; Poulain, Magali; Garnier, Sophie; Sanguignol, Frédéric; Mauriège, Pascale
2007-01-01
To examine the impact of a 3-week weight-reducing program on body composition, physical condition, health-related quality of life, and eating behaviors of sedentary, obese (body mass index, 29-35 kg/m) women, according to menopausal status and menopause duration (<5, >or=5, and >or=10 y). Thirteen premenopausal and 27 postmenopausal women received a dietary plan of 1,400 +/- 200 kcal/day and completed 110-minute endurance exercise 6 days per week. Body mass index, fat mass, lean mass, distance walked in the Six-Minute Walk Test, health-related quality of life estimated by the 36-item Short Form Health Survey (SF-36), and eating behaviors (restriction, disinhibition, and susceptibility to hunger) assessed by the Three-Factor Eating Questionnaire were determined before and after weight reduction. Body mass index and fat mass decreased (P < 0.0001), whereas distance walked increased in both groups after weight reduction (P < 0.001). Although the SF-36 mental component score increased after weight loss in both groups (P < 0.0001), the SF-36 physical component score increased in postmenopausal women only (P < 0.001). Restriction increased (P < 0.0001), whereas disinhibition and susceptibility to hunger decreased after weight reduction (P < 0.001 and P < 0.01, respectively) in both groups. Distance walked and SF-36 physical component score after weight loss were higher in women whose menopause ranged between 5 and 9 years and exceeded 10 years, respectively (P < 0.01). Our study shows that a short-term weight-reducing program combining caloric restriction and physical activity has a favorable impact on women's body composition, physical condition, health-related quality of life, and eating behaviors irrespective of their menopausal status.
NASA Technical Reports Server (NTRS)
Jadaan, Osama
2001-01-01
Present capabilities of the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code include probabilistic life prediction of ceramic components subjected to fast fracture, slow crack growth (stress corrosion), and cyclic fatigue failure modes. Currently, this code has the capability to compute the time-dependent reliability of ceramic structures subjected to simple time-dependent loading. For example, in slow crack growth (SCG) type failure conditions CARES/Life can handle the cases of sustained and linearly increasing time-dependent loads, while for cyclic fatigue applications various types of repetitive constant amplitude loads can be accounted for. In real applications applied loads are rarely that simple, but rather vary with time in more complex ways such as, for example, engine start up, shut down, and dynamic and vibrational loads. In addition, when a given component is subjected to transient environmental and or thermal conditions, the material properties also vary with time. The objective of this paper is to demonstrate a methodology capable of predicting the time-dependent reliability of components subjected to transient thermomechanical loads that takes into account the change in material response with time. In this paper, the dominant delayed failure mechanism is assumed to be SCG. This capability has been added to the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code, which has also been modified to have the ability of interfacing with commercially available FEA codes executed for transient load histories. An example involving a ceramic exhaust valve subjected to combustion cycle loads is presented to demonstrate the viability of this methodology and the CARES/Life program.
Natural variation of fecundity components in a widespread plant with dimorphic seeds
NASA Astrophysics Data System (ADS)
Braza, Rita; Arroyo, J.; García, M. B.
2010-09-01
The number and size of seeds are the basis of the quantity and quality components of female reproductive fitness in plants, playing a central role in the evolutionary ecology of life history diversification. In this study we show and analyze the natural variability of several fecundity variables (fruit set, seed production per fruit, seed size, total seed production per plant, and proportion of small seeds) in Plantago coronopus, a widespread, short-lived herb with dimorphic seeds. The structure of such variability was examined at the individual, population (eight locations with different environments within the same region), and life history levels (annual vs perennial), and correlated to soil fertility. There was no divergence associated to the life history for any of the variables studied. Total seed production (the quantity component of female fitness) was correlated with maternal resources, while the size of the large mucilaginous, basal seeds, and the proportion of the small apical seeds (quality component) were more associated to environmental resources. Thus, internal and external resources shape different fitness components, maximizing seed production, and fitting the size and proportion of different kind of seeds to local conditions irrespective of life history. P. coronopus illustrates the versatility of short-lived widespread plants to combine fecundity traits in a flexible manner, in order to increase fitness at each of the many possible habitats they occupy over heterogeneous environments.
Life-cycle environmental inventory of passenger transportation modes in the United States
NASA Astrophysics Data System (ADS)
Chester, Mikhail Vin
To appropriately mitigate environmental impacts from transportation, it is necessary for decision makers to consider the life-cycle energy consumption and emissions associated with each mode. A life-cycle energy, greenhouse gas, and criteria air pollutant emissions inventory is created for the passenger transportation modes of automobiles, urban buses, heavy rail transit, light rail transit, and aircraft in the U.S. Each mode's inventory includes an assessment of vehicles, infrastructure, and fuel components. For each component, analysis is performed for material extraction through use and maintenance in both direct and indirect (supply chain) processes. For each mode's life-cycle components, energy inputs and emission outputs are determined. Energy inputs include electricity and petroleum-based fuels. Emission outputs include greenhouse gases (CO2, CH4, and N2O) and criteria pollutants (CO, SO2, NOx , VOCs, and PM). The inputs and outputs are normalized by vehicle lifetime, vehicle mile traveled, and passenger mile traveled. A consistent system boundary is applied to all modal inventories which captures the entire life-cycle, except for end-of-life. For each modal life-cycle component, both direct and indirect processes are included if possible. A hybrid life-cycle assessment approach is used to estimate the components in the inventories. We find that life-cycle energy inputs and emission outputs increase significantly compared to the vehicle operational phase. Life-cycle energy consumption is 39-56% larger than vehicle operation for autos, 38% for buses, 93-160% for rail, and 19-24% for air systems per passenger mile traveled. Life-cycle greenhouse gas emissions are 47-65% larger than vehicle operation for autos, 43% for buses, 39-150% for rail, and 24-31% for air systems per passenger mile traveled. The energy and greenhouse gas increases are primarily due to vehicle manufacturing and maintenance, infrastructure construction, and fuel production. For criteria air pollutants, life-cycle components often dominate total emissions and can be a magnitude larger than operational counterparts. Per passenger mile traveled, total SO2 emissions (between 350 and 460 mg) are 19-27 times larger than operational emissions as a result of electricity generation in vehicle manufacturing, infrastructure construction, and fuel production. NOx emissions increase 50-73% for automobiles, 24% for buses, 13-1300% for rail, and 19-24% for aircraft. Non-tailpipe VOCs are 27-40% of total automobile, 71-95% of rail, and 51-81% of air total emissions. Infrastructure and parking construction are major components of total PM10 emissions resulting in total emissions over three times larger than operational emissions for autos and even larger for many rail systems and aircraft (the major contributor being emissions from hot-mix asphalt plants and concrete production). Infrastructure construction and operation as well as vehicle manufacturing increase total CO emissions by 5-17 times from tailpipe performance for rail and 3-9 times for air. A case study comparing the environmental performance of metropolitan regions is presented as an application of the inventory results. The San Francisco Bay Area, Chicago, and New York City are evaluated capturing passenger transportation life-cycle energy inputs and greenhouse gas and criteria air pollutant emissions. The regions are compared between off-peak and peak travel as well as personal and public transit. Additionally, healthcare externalities are computed from vehicle emissions. It is estimated that life-cycle energy varies from 6.3 MJ/PMT in the Bay Area to 5.7 MJ/PMT in Chicago and 5.3 MJ/PMT in New York for an average trip. Life-cycle GHG emissions range from 480 g CO2e/PMT in the Bay Area to 440 g CO2e/PMT for Chicago and 410 g CO 2e/PMT in New York. CAP emissions vary depending on the pollutant with differences as large as 25% between regions. Life-cycle CAP emissions are between 11% and 380% larger than their operational counterparts. Peak travel, with typical higher riderships, does not necessarily environmentally outperform off-peak travel due to the large share of auto PMT and less than ideal operating conditions during congestion. The social costs of travel range from ¢51 (in ¢2007) per auto passenger per trip during peak in New York to ¢6 per public transit passenger per trip during peak hours in the Bay Area and New York. Average personal transit costs are around ¢30 while public transit ranges from ¢28 to ¢41. (Abstract shortened by UMI.)
Materials and structural aspects of advanced gas-turbine helicopter engines
NASA Technical Reports Server (NTRS)
Freche, J. C.; Acurio, J.
1979-01-01
Advances in materials, coatings, turbine cooling technology, structural and design concepts, and component-life prediction of helicopter gas-turbine-engine components are presented. Stationary parts including the inlet particle separator, the front frame, rotor tip seals, vanes and combustors and rotating components - compressor blades, disks, and turbine blades - are discussed. Advanced composite materials are considered for the front frame and compressor blades, prealloyed powder superalloys will increase strength and reduce costs of disks, the oxide dispersion strengthened alloys will have 100C higher use temperature in combustors and vanes than conventional superalloys, ceramics will provide the highest use temperature of 1400C for stator vanes and 1370C for turbine blades, and directionally solidified eutectics will afford up to 50C temperature advantage at turbine blade operating conditions. Coatings for surface protection at higher surface temperatures and design trends in turbine cooling technology are discussed. New analytical methods of life prediction such as strain gage partitioning for high temperature prediction, fatigue life, computerized prediction of oxidation resistance, and advanced techniques for estimating coating life are described.
Structures and mechanisms - Streamlining for fuel economy
NASA Technical Reports Server (NTRS)
Card, M. F.
1983-01-01
The design of prospective NASA space station components which inherently possess the means for structural growth without compromising initial system characteristics is considered. In structural design terms, space station growth can be achieved by increasing design safety factors, introducing dynamic isolators to prevent loads from reaching the initial components, or preplanning the refurbishment of the original structure with stronger elements. Design tradeoffs will be based on the definition of on-orbit loads, including docking and maneuvering, whose derived load spectra will allow the estimation of fatigue life. Improvements must be made in structural materials selection in order to reduce contamination, slow degradation, and extend the life of coatings. To minimize on-orbit maintenance, long service life lubrication systems with advanced sealing devices must be developed.
Assessing state efforts to integrate transportation, land use and climate change.
DOT National Transportation Integrated Search
2016-12-01
Climate change is increasingly recognized as a threat to life on earth. Continued emission of greenhouse gases will cause further : warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, perv...
Ahlstrand, Inger; Vaz, Sharmila; Falkmer, Torbjörn; Thyberg, Ingrid; Björk, Mathilda
2017-06-01
To study whether personal factors (self-efficacy and pain acceptance) mediate the relationship between pain and performance of valued life activities in persons with rheumatoid arthritis. Persons with rheumatoid arthritis for at least four years ( n = 737; 73% women) answered a questionnaire measuring self-efficacy, pain acceptance, performance of valued life activities, and self-rated pain. Relationships among these constructs were explored using univariate and multivariate analyses. Structural equation modelling was then used to examine the mediational role of personal factors on the relationship between pain and performance of valued life activities. A direct negative association between pain and performance of valued life activities was identified ( Beta = .34, P < .001). This suggests that people with rheumatoid arthritis who had higher levels of pain has increased difficulties in performing valued life activities. Self-efficacy and activity engagement component of pain acceptance mediated the relationship between pain and performance of valued life activities, however the pain willingness component of pain acceptance did not influence participation in valued life activities. These findings highlight the importance of considering personal factors, such as pain acceptance and self-efficacy, in facilitating participation in valued life activities.
On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dennis H. LeMieux
2004-10-01
Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land -based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems; a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization.« less
Smart Sensor System for NDE or Corrosion in Aging Aircraft
NASA Technical Reports Server (NTRS)
Bar-Cohen, Y.; Marzwell, N.; Osegueda, R.; Ferregut, C.
1998-01-01
The extension of the operation life of military and civilian aircraft rather than replacing them with new ones is increasing the probability of aircraft component failure as a result of aging. Aircraft that already have endured a long srvice life of more than 40 years are now being considered for another 40 years of service.
Erosion Coatings Developed to Increase the Life and Durability of Composites
NASA Technical Reports Server (NTRS)
Sutter, James K.; Naik, Subhash K.; Bowman, Cheryl L.; Siefker, Robert; Miyoshi, Kazuhisa; Perusek, Gail P.
2004-01-01
Both the NASA Glenn Research Center and the Allison Advanced Development Company (AADC) have worked to develop and demonstrate erosion-resistant coatings that would increase the life and durability of composite materials used in commercial aircraft engines. These composite materials reduce component weight by 20 to 30 percent and result in less fuel burn and emissions and more fuel savings. Previously, however, their use was limited because of poor erosion resistance, which causes concerns about safety and leads to high maintenance costs. The coatings were tested by the University of Cincinnati, and the composites were manufactured by Texas Composites and coated by Engelhard and NASA Glenn. Rolls-Royce Corporation uses composite materials, which are stronger and less dense than steel or titanium, to make bypass vanes for their AE3007 engines. These engines are widely used in regional jet aircraft (Embraer) and unmanned air vehicles such as the Northrop Grumman Global Hawk. Coatings developed by NASA/Rolls-Royce can reduce erosion from abrasive materials and from impurities in the air that pass over these vanes, allowing Rolls-Royce to take advantage of the benefits of composite materials over titanium without the added costs of increased maintenance and/or engine failure. The Higher Operating Temperature Propulsion Components (HOTPC) Project developed cost-effective, durable coatings as part of NASA's goal to increase aviation system capacity growth. These erosion coatings will reduce the number of special inspections or instances of discontinued service due to erosion, allowing aircraft capacity to be maintained without inconveniencing the traveling public. A specific example of extending component life showed that these coatings increased the life of graphite fiber and polymer composite bypass vanes up to 8 times over that of the uncoated vanes. This increased durability allows components to operate to full design life without the fear of wear or failure. Recently, Rolls-Royce completed over 2000 hr of engine testing with the coated fan exit bypass vanes. There was no loss of coating after nearly 5000 typical engine cycles. Midway through the engine tests, the coated vanes were removed from the engine during a scheduled maintenance and inspection period. The vanes were shipped back to Glenn, where they underwent further stress testing in the Structural Dynamics Lab, mimicking more extreme conditions than those typical of the AE3007 engine cycle. These vanes were then replaced in the AE3007 and subjected to another 1000 hr of engine tests. Once again, there was no loss of coating and only a minimal appearance of cracking.
Computational simulation of acoustic fatigue for hot composite structures
NASA Technical Reports Server (NTRS)
Singhal, S. N.; Nagpal, V. K.; Murthy, P. L. N.; Chamis, C. C.
1991-01-01
This paper presents predictive methods/codes for computational simulation of acoustic fatigue resistance of hot composite structures subjected to acoustic excitation emanating from an adjacent vibrating component. Select codes developed over the past two decades at the NASA Lewis Research Center are used. The codes include computation of (1) acoustic noise generated from a vibrating component, (2) degradation in material properties of the composite laminate at use temperature, (3) dynamic response of acoustically excited hot multilayered composite structure, (4) degradation in the first-ply strength of the excited structure due to acoustic loading, and (5) acoustic fatigue resistance of the excited structure, including propulsion environment. Effects of the laminate lay-up and environment on the acoustic fatigue life are evaluated. The results show that, by keeping the angled plies on the outer surface of the laminate, a substantial increase in the acoustic fatigue life is obtained. The effect of environment (temperature and moisure) is to relieve the residual stresses leading to an increase in the acoustic fatigue life of the excited panel.
Computational simulation of acoustic fatigue for hot composite structures
NASA Technical Reports Server (NTRS)
Singhal, Surendra N.; Murthy, Pappu L. N.; Chamis, Christos C.; Nagpal, Vinod K.; Sutjahjo, Edhi
1991-01-01
Predictive methods/computer codes for the computational simulation of acoustic fatigue resistance of hot composite structures subjected to acoustic excitation emanating from an adjacent vibrating component are discussed. Select codes developed over the past two decades at the NASA Lewis Research Center are used. The codes include computation of acoustic noise generated from a vibrating component, degradation in material properties of a composite laminate at use temperature, dynamic response of acoustically excited hot multilayered composite structure, degradation in the first ply strength of the excited structure due to acoustic loading, and acoustic fatigue resistance of the excited structure, including the propulsion environment. Effects of the laminate lay-up and environment on the acoustic fatigue life are evaluated. The results show that, by keeping the angled plies on the outer surface of the laminate, a substantial increase in the acoustic fatigue life is obtained. The effect of environment (temperature and moisture) is to relieve the residual stresses leading to an increase in the acoustic fatigue life of the excited panel.
Heritage contribution in sustainable city
NASA Astrophysics Data System (ADS)
Rostami, R.; Khoshnava, S. M.; Lamit, H.
2014-02-01
The concept of sustainability has been an integral part of development work since the late 1970s. Sustainability is no longer a buzzword but a reality that must be addressed by cities all over the world. Increasing empirical evidence indicates that city sustainability is not just related to technical issues, such as carbon emissions, energy consumption and waste management, or on the economic aspects of urban regeneration and growth, but also it covers social well-being of different groups living within increasingly cosmopolitan towns and cities. Heritage is seen as a major component of quality of life, features that give a city its unique character and provide the sense of belonging that lies at the core of cultural identity. In other words, heritage by providing important social and psychological benefits enrich human life with meanings and emotions, and raise quality of life as a key component of sustainability. The purpose of this paper, therefore, is to examine the role that built cultural heritage can play within sustainable urban development.
Kouidi, E
2004-05-01
Health-related quality of life (HRQoL) consists of a number of components like functional status, psychological and social functioning, cognition and disease and treatment-related symptoms. End-stage renal disease (ESRD) patients display emotional disturbances, as well as non-adherence to treatment and fluid and food intake, depression, anxiety, social withdrawal and cardiovascular and other co-existing disease morbidity. They have very low functional capacity and physical limitations in their daily activities that affect their mortality and morbidity. Exercise training in ESRD patients is effective in increasing work related activities and important components of their daily life and improving physical functioning. A physical rehabilitation program also leads to a reduction in depression and improvement in family and social interactions. Therefore, renal rehabilitation should be considered as an important therapeutic method for improving physical fitness, social function, well-being and thus health-adjusted quality of life in ESRD patients.
Health-related quality of life before and after bariatric surgery in adolescents.
Loux, Tara J; Haricharan, Ramanath N; Clements, Ronald H; Kolotkin, Ronette L; Bledsoe, Samuel E; Haynes, Beverly; Leath, Teresa; Harmon, Carroll M
2008-07-01
Recent data reaffirm decreased health-related quality of life (HRQL) in obese adults and children. Health-related quality of life is markedly improved after bariatric surgery in adults. Little HRQL data are available in adolescents undergoing bariatric surgery. Sixteen patients (14-20 years old) underwent gastric bypass. Thirteen patients completed a general HRQL measure (Short Form 36 [SF-36]) before surgery. Of these, 9 completed the SF-36 again at various follow-up times, as well as a measure of weight-related quality of life (Impact of Weight on Quality of Life-Lite). Three patients completed postsurgical forms only. Data were analyzed using t test and analysis of variance. Results are reported as mean +/- SD. Mean age and body mass index at operation were 18.5 +/- 1.7 years and 54 +/- 7.6 kg/m(2). Postoperatively, patients lost an average of 66% +/- 29% excess weight over a mean follow-up of 17 +/- 12 (range, 1-39) months. Mean preoperative SF-36 physical component score was 34.7 +/- 10 and mental component score was 40.6 +/- 13.5 (adult population mean = 50.0 +/- 10 for each). At last follow-up, mean physical component score had increased to 55.5 +/- 5, and mental component score, to 55.2 +/- 8.6 (P < .0001). Adolescent Impact of Weight on Quality of Life-Lite scores after surgery did not differ from means for normal weight adults (93% +/- 7% vs 96% +/- 7%, P = .15). Health-related quality of life in adolescents and young adults undergoing bariatric surgery improves dramatically in early follow-up. Long-term data are needed to definitively study this surgical therapy for obesity in adolescents.
Turbine blade vibration dampening
Cornelius, C.C.; Pytanowski, G.P.; Vendituoli, J.S.
1997-07-08
The present turbine wheel assembly increases component life and turbine engine longevity. The combination of the strap and the opening combined with the preestablished area of the outer surface of the opening and the preestablished area of the outer circumferential surface of the strap and the friction between the strap and the opening increases the life and longevity of the turbine wheel assembly. Furthermore, the mass ``M`` or combined mass ``CM`` of the strap or straps and the centrifugal force assist in controlling vibrations and damping characteristics. 5 figs.
Turbine blade vibration dampening
Cornelius, Charles C.; Pytanowski, Gregory P.; Vendituoli, Jonathan S.
1997-07-08
The present turbine wheel assembly increases component life and turbine engine longevity. The combination of the strap and the opening combined with the preestablished area of the outer surface of the opening and the preestablished area of the outer circumferential surface of the strap and the friction between the strap and the opening increases the life and longevity of the turbine wheel assembly. Furthermore, the mass "M" or combined mass "CM" of the strap or straps and the centrifugal force assist in controlling vibrations and damping characteristics.
ERIC Educational Resources Information Center
Adamo, Elyse K.; Wu, Jenny; Wolery, Mark; Hemmeter, Mary Louise; Ledford, Jennifer R.; Barton, Erin E.
2015-01-01
Children with Down syndrome may be at increased risk of problems associated with inactivity. Early intervention to increase physical activity may lead to increased participation in typical activities and long-term increases in quality of life (e.g., decreased likelihood of obesity-related illness). A multi-component intervention, including video…
Prolonging thermal barrier coated specimen life by thermal cycle management
NASA Technical Reports Server (NTRS)
Hendricks, R. C.; Mcdonald, G.; Poolos, N. P.
1981-01-01
Thermal barrier coatings applied to the heated side of engine components such as seals, combustor, and blades of a gas turbine offer a potential increase in efficiency through the use of higher gas temperatures or less cooling air or benefits arising from extended component life by reducing component metal temperatures. The considered investigation has the objective to show that while a thermal barrier coated (TBC) specimen can be brought to a fixed temperature using various fuel-air ratio (F/A) values, lower calculated stresses are associated with lower (F/A) values. This implies that control of (F/A) values (i.e., rates of heat input) during the starting transient and to a lesser extent during shutdown and operation, offers a potential method of improving TBC lifetime through thermal cycle management.
Core self-evaluations and Snyder's hope theory in persons with spinal cord injuries.
Smedema, Susan Miller; Chan, Jacob Yuichung; Phillips, Brian N
2014-11-01
The objective of the study was to evaluate a motivational model of core self-evaluations (CSE), hope (agency and pathways thinking), participation, and life satisfaction in persons with spinal cord injuries. A cross-sectional, correlational design with path analysis was used to evaluate the model. 187 adults with spinal cord injuries participated in this study. The results indicated an excellent fit between the data and the proposed model. Specifically, CSE was found to directly predict agency and pathways thinking, participation, and life satisfaction. CSE was also found to indirectly predict participation and life satisfaction through agency thinking. Although CSE contributes directly to participation and life satisfaction, it also has a unique role in increasing individuals' motivation to pursue goals, which also predicts participation and life satisfaction. Counseling interventions should be multifaceted and address the components of CSE to increase hope, participation, and life satisfaction. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
ERIC Educational Resources Information Center
Kim, Hyunjee; Lee, Taeyong; Lee, Sokgoo; Kim, Keonyeop; Lee, Sungkook; Kam, Sin; Ahn, Sangnam; Cho, Jinmyoung; Ory, Marcia G.
2012-01-01
This study aims to examine the functional status of Korean centenarians, who have crossed the relatively rare but increasingly common life transition of living for a century. As functional health is one of the essential components of healthy aging, our primary objective is to identify the correlates of two aspects of functioning, activities of…
Pathways Between Discrimination and Quality of Life in Patients with Type 2 Diabetes
Achuko, Obinna; Walker, Rebekah J.; Campbell, Jennifer A.; Dawson, Aprill Z.
2016-01-01
Abstract Background: Discrimination is a social determinant that has been linked to poor physical and mental health outcomes. This study aimed to examine the pathway whereby discrimination influences quality of life in patients with type 2 diabetes. Subjects and Methods: Six hundred fifteen patients were recruited from two adult primary care clinics in the southeastern United States. Measures included perceived discrimination, perceived stress, social support, and social cohesion and were based on a theoretical model for the pathways by which perceived discrimination influences mental and physical health. Quality of life was measured using the SF-12 questionnaire. Results: The final model [χ2(106) = 157.35, P = 0.009, R2 = 0.99, root mean square error of approximation = 0.03, comparative fit index = 0.99] indicates direct effects of higher perceived stress (r = −1.02, P < 0.05) and lower social support (r = 0.36, P < 0.001) significantly related to decreased mental health component score (MCS) of quality of life. Discrimination and social cohesion were not significantly directly related to MCS. However, higher discrimination (r = 0.47, P < 0.001), higher social cohesion (r = 0.14, P < 0.05), and lower social support (r = −0.43, P < 0.001) were significantly directly related to increased stress. No significant paths were found for the physical component score of quality of life. Conclusions: Perceived discrimination was significantly associated with stress and served as a pathway to influence the mental health component of quality of life (MCS). Social support had a direct and an indirect effect on MCS through a negative association with stress. These results suggest that future interventions should be developed to decrease stress and increase social support surrounding discrimination to improve the MCS of quality of life in patients with diabetes. PMID:26866351
Pathways Between Discrimination and Quality of Life in Patients with Type 2 Diabetes.
Achuko, Obinna; Walker, Rebekah J; Campbell, Jennifer A; Dawson, Aprill Z; Egede, Leonard E
2016-03-01
Discrimination is a social determinant that has been linked to poor physical and mental health outcomes. This study aimed to examine the pathway whereby discrimination influences quality of life in patients with type 2 diabetes. Six hundred fifteen patients were recruited from two adult primary care clinics in the southeastern United States. Measures included perceived discrimination, perceived stress, social support, and social cohesion and were based on a theoretical model for the pathways by which perceived discrimination influences mental and physical health. Quality of life was measured using the SF-12 questionnaire. The final model [χ(2)(106) = 157.35, P = 0.009, R(2) = 0.99, root mean square error of approximation = 0.03, comparative fit index = 0.99] indicates direct effects of higher perceived stress (r = -1.02, P < 0.05) and lower social support (r = 0.36, P < 0.001) significantly related to decreased mental health component score (MCS) of quality of life. Discrimination and social cohesion were not significantly directly related to MCS. However, higher discrimination (r = 0.47, P < 0.001), higher social cohesion (r = 0.14, P < 0.05), and lower social support (r = -0.43, P < 0.001) were significantly directly related to increased stress. No significant paths were found for the physical component score of quality of life. Perceived discrimination was significantly associated with stress and served as a pathway to influence the mental health component of quality of life (MCS). Social support had a direct and an indirect effect on MCS through a negative association with stress. These results suggest that future interventions should be developed to decrease stress and increase social support surrounding discrimination to improve the MCS of quality of life in patients with diabetes.
NASA Technical Reports Server (NTRS)
Johnson, Michael R.; Gehling, Russ; Head, Ray
2006-01-01
The Mars Reconnaissance Orbiter (MRO) spacecraft has three two-axis gimbal assemblies that support and move the High Gain Antenna and two solar array wings. The gimbal assemblies are required to move almost continuously throughout the mission's seven-year lifetime, requiring a large number of output revolutions for each actuator in the gimbal assemblies. The actuator for each of the six axes consists of a two-phase brushless dc motor with a direct drive to the wave generator of a size-32 cup-type harmonic gear. During life testing of an actuator assembly, the harmonic gear teeth failed completely, leaving the size-32 harmonic gear with a maximum output torque capability less than 10% of its design capability. The investigation that followed the failure revealed limitations of the heritage material choices that were made for the harmonic gear components that had passed similar life requirements on several previous programs. Additionally, the methods used to increase the stiffness of a standard harmonic gear component set, while accepted practice for harmonic gears, is limited in its range. The stiffness of harmonic gear assemblies can be increased up to a maximum stiffness point that, if exceeded, compromises the reliability of the gear components for long life applications.
Predictors and Outcomes of Health–Related Quality of Life in Adults with CKD
Lash, James P.; Xie, Dawei; Pan, Qiang; DeLuca, Jennifer; Kanthety, Radhika; Kusek, John W.; Lora, Claudia M.; Nessel, Lisa; Ricardo, Ana C.; Wright Nunes, Julie; Fischer, Michael J.
2016-01-01
Background and objectives Low health–related quality of life is associated with increased mortality in patients with ESRD. However, little is known about demographic and clinical factors associated with health–related quality of life or its effect on outcomes in adults with CKD. Design, settings, participants, & measurements Data from 3837 adult participants with mild to severe CKD enrolled in the prospective observational Chronic Renal Insufficiency Cohort and Hispanic Chronic Renal Insufficiency Cohort Studies were analyzed. Health–related quality of life was assessed at baseline with the Kidney Disease Quality of Life-36 and its five subscales: mental component summary, physical component summary, burden of kidney disease (burden), effects of kidney disease (effects), and symptoms and problems of kidney disease (symptoms). Low health–related quality of life was defined as baseline score >1 SD below the mean. Using Cox proportional hazards analysis, the relationships between low health–related quality of life and the following outcomes were examined: (1) CKD progression (50% eGFR loss or incident ESRD), (2) incident cardiovascular events, and (3) all-cause death. Results Younger age, women, low education, diabetes, vascular disease, congestive heart failure, obesity, and lower eGFR were associated with low baseline health–related quality of life (P<0.05). During a median follow-up of 6.2 years, there were 1055 CKD progression events, 841 cardiovascular events, and 694 deaths. Significantly higher crude rates of CKD progression, incident cardiovascular events, and all-cause death were observed among participants with low health–related quality of life in all subscales (P<0.05). In fully adjusted models, low physical component summary, effects, and symptoms subscales were independently associated with a higher risk of incident cardiovascular events and death, whereas low mental component summary was independently associated with a higher risk of death (P<0.05). Low health–related quality of life was not associated with CKD progression. Conclusions Low health–related quality of life across several subscales was independently associated with a higher risk of incident cardiovascular events and death but not associated with CKD progression. PMID:27246012
ERIC Educational Resources Information Center
Downs, Karen M.; Wagner, Mervyn K.
The Individualized Quality of Life Scale (IQOLS) is a two-component scale designed to measure the quality of life (QOL) of cancer patients. The two components are the patient's satisfaction with 14 different life areas and the importance of the life areas to the individual. By combining the two components, an overall QOL score can be obtained that…
Hua, Yang; Liu, Zhanqiang
2018-05-24
Residual stresses of turned Inconel 718 surface along its axial and circumferential directions affect the fatigue performance of machined components. However, it has not been clear that the axial and circumferential directions are the principle residual stress direction. The direction of the maximum principal residual stress is crucial for the machined component service life. The present work aims to focuses on determining the direction and magnitude of principal residual stress and investigating its influence on fatigue performance of turned Inconel 718. The turning experimental results show that the principal residual stress magnitude is much higher than surface residual stress. In addition, both the principal residual stress and surface residual stress increase significantly as the feed rate increases. The fatigue test results show that the direction of the maximum principal residual stress increased by 7.4%, while the fatigue life decreased by 39.4%. The maximum principal residual stress magnitude diminished by 17.9%, whereas the fatigue life increased by 83.6%. The maximum principal residual stress has a preponderant influence on fatigue performance as compared to the surface residual stress. The maximum principal residual stress can be considered as a prime indicator for evaluation of the residual stress influence on fatigue performance of turned Inconel 718.
On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dennis H. LeMieux
2005-04-01
Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs havemore » been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less
ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dennis H. LeMieux
2003-10-01
Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less
ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dennis H. LeMieux
2003-07-01
Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less
On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dennis H. LeMieux
2005-10-01
Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Power Generation, Inc proposed a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs havemore » been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Power Generation, Inc. has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less
Ukubuiwe, Azubuike Christian; Olayemi, Israel Kayode; Omalu, Innocent Chukwuemeka James; Arimoro, Francis Ofurum; Baba, Bulus Musa; Ukubuiwe, Chinenye Catherine
2018-01-01
This study investigated the effects of varying photoperiodic conditions on critical life stages’ parameters of Culex quinquefasciatus. To this end, first larval stage was reared under different constant photoperiodic regimens: 0, 6 (short), 12 (equal), 13 (prevailing condition), and 18 and 24 (long) hours of light (hL). Duration of development, survivorship, emergence successes, adult longevity, caloric indices (CIs), and utilisation of teneral reserves for metamorphosis at each regimen were monitored. Analyses revealed significant negative effects of increasing photoperiod on all entomological variables measured. Short photo-phases elicited faster development times, increased life stages’ survivorship and number at emergence, adult longevity, and CI for all life stages while increasing teneral components for adult life traits. The information generated in this study is important in understanding the role played by photoperiod in disease transmission and for development of integrated vector control strategies based on environmental manipulation. PMID:29636636
NASA Technical Reports Server (NTRS)
Kalluri, Sreeramesh
2013-01-01
Structural materials used in engineering applications routinely subjected to repetitive mechanical loads in multiple directions under non-isothermal conditions. Over past few decades, several multiaxial fatigue life estimation models (stress- and strain-based) developed for isothermal conditions. Historically, numerous fatigue life prediction models also developed for thermomechanical fatigue (TMF) life prediction, predominantly for uniaxial mechanical loading conditions. Realistic structural components encounter multiaxial loads and non-isothermal loading conditions, which increase potential for interaction of damage modes. A need exists for mechanical testing and development verification of life prediction models under such conditions.
Clinical interventions for late-life anxious depression.
Diefenbach, Gretchen J; Goethe, John
2006-01-01
Anxiety symptoms are frequently present in patients with late-life depression. The designation "anxious depression" has been used to describe major depressive disorder (MDD) accompanied by clinically significant but subsyndromal anxiety symptoms. MDD may also present comorbid with diagnosable anxiety disorders, although this presentation is less common in late life. Diagnosis of anxious depression in the elderly is complicated by several factors (eg, their tendency to experience and report psychiatric symptoms as somatic illness) and is associated with a more severe clinical presentation, increased risk for suicidal ideation, increased disability, and poorer prognosis. Standard pharmacotherapy for depression may be sufficient but for many patients must be modified or augmented. Psychosocial interventions may also be an important component in the treatment of these patients, although no specific psychosocial treatments have been developed for late-life anxious depression.
Research on the Fatigue Flexural Performance of RC Beams Attacked by Salt Spray
NASA Astrophysics Data System (ADS)
Mao, Jiang-hong; Xu, Fang-yuan; Jin, Wei-liang; Zhang, Jun; Wu, Xi-xi; Chen, Cai-sheng
2018-04-01
The fatigue flexural performance of RC beams attacked by salt spray was studied. A testing method involving electro osmosis, electrical accelerated corrosion and salt spray was proposed. This corrosion process method effectively simulates real-world salt spray and fatigue loading exerted by RC components on sea bridges. Four RC beams that have different stress amplitudes were tested. It is found that deterioration by corrosion and fatigue loading reduces the fatigue life of the RC and decreases the ability of deformation. The fatigue life and deflection ability could be reduced by increasing the stress amplitude and the corrosion duration time. The test result demonstrates that this experimental method can couple corrosion deterioration and fatigue loading reasonably. This procedure may be applied to evaluate the fatigue life and concrete durability of RC components located in a natural salt spray environment.
Weibull-Based Design Methodology for Rotating Aircraft Engine Structures
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin; Hendricks, Robert C.; Soditus, Sherry
2002-01-01
The NASA Energy Efficient Engine (E(sup 3)-Engine) is used as the basis of a Weibull-based life and reliability analysis. Each component's life and thus the engine's life is defined by high-cycle fatigue (HCF) or low-cycle fatigue (LCF). Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine Weibull slope increases, the predicted lives decrease. The predicted engine lives L(sub 5) (95 % probability of survival) of approximately 17,000 and 32,000 hr do correlate with current engine maintenance practices without and with refurbishment. respectively. The individual high pressure turbine (HPT) blade lives necessary to obtain a blade system life L(sub 0.1) (99.9 % probability of survival) of 9000 hr for Weibull slopes of 3, 6 and 9, are 47,391 and 20,652 and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9 %, the predicted disk system life L(sub 0.1) can vary from 9,408 to 24,911 hr.
Dorian, Paul; Guerra, Peter G; Kerr, Charles R; O'Donnell, Suzan S; Crystal, Eugene; Gillis, Anne M; Mitchell, L Brent; Roy, Denis; Skanes, Allan C; Rose, M Sarah; Wyse, D George
2009-06-01
Atrial fibrillation (AF) is commonly associated with impaired quality of life. There is no simple validated scale to quantify the functional illness burden of AF. The Canadian Cardiovascular Society Severity in Atrial Fibrillation (CCS-SAF) scale is a bedside scale that ranges from class 0 to 4, from no effect on functional quality of life to a severe effect on life quality. This study was performed to validate the scale. In 484 patients with documented AF (62.2+/-12.5 years of age, 67% men; 62% paroxysmal and 38% persistent/permanent), the SAF class was assessed and 2 validated quality-of-life questionnaires were administered: the SF-36 generic scale and the disease-specific AFSS (University of Toronto Atrial Fibrillation Severity Scale). There is a significant linear graded correlation between the SAF class and measures of symptom severity, physical and emotional components of quality of life, general well-being, and health care consumption related to AF. Patients with SAF class 0 had age- and sex-standardized SF-36 scores of 0.15+/-0.16 and -0.04+/-0.31 (SD units), that is, units away from the mean population score for the mental and physical summary scores, respectively. For each unit increase in SAF class, there is a 0.36 and 0.40 SD unit decrease in the SF-36 score for the physical and mental components. As the SAF class increases from 0 to 4, the symptom severity score (range, 0 to 35) increases from 4.2+/-5.0 to 18.4+/-7.8 (P<0.0001). The CCS-SAF scale is a simple semiquantitative scale that closely approximates patient-reported subjective measures of quality of life in AF and may be practical for clinical use.
Mori, Yuka; Downs, Jenny; Wong, Kingsley; Anderson, Barbara; Epstein, Amy; Leonard, Helen
2017-01-19
Although research in this area remains sparse, raising a child with some genetic disorders has been shown to adversely impact maternal health and family quality of life. The aim of this study was to investigate such impacts in families with a child with the CDKL5 disorder, a newly recognised genetic disorder causing severe neurodevelopmental impairments and refractory epilepsy. Data were sourced from the International CDKL5 Disorder Database to which 192 families with a child with a pathogenic CDKL5 mutation had provided data by January 2016. The Short Form 12 Health Survey Version 2, yielding a Physical Component Summary and a Mental Component Summary score, was used to measure primary caregiver's wellbeing. The Beach Center Family Quality of Life Scale was used to measure family quality of life. Linear regression analyses were used to investigate relationships between child and family factors and the various subscale scores. The median (range) age of the primary caregivers was 37.0 (24.6-63.7) years and of the children was 5.2 (0.2-34.1) years. The mean (SD) physical and mental component scores were 53.7 (8.6) and 41.9 (11.6), respectively. In mothers aged 25-54 years the mean mental but not the physical component score was lower than population norms. After covariate adjustment, caregivers with a tube-fed child had lower mean physical but higher mean mental component scores than those whose child fed orally (coefficient = -4.80 and 6.79; p = 0.009 and 0.012, respectively). Child sleep disturbances and financial hardship were negatively associated with the mental component score. The mean (SD) Beach Center Family Quality of Life score was 4.06 (0.66) and those who had used respite services had lower scores than those who had not across the subscales. Emotional wellbeing was considerably impaired in this caregiver population, and was particularly associated with increased severity of child sleep problems and family financial difficulties. Family quality of life was generally rated lowest in those using respite care extensively, suggesting that these families may be more burdened by daily caregiving.
Real-Time Aircraft Engine-Life Monitoring
NASA Technical Reports Server (NTRS)
Klein, Richard
2014-01-01
This project developed an inservice life-monitoring system capable of predicting the remaining component and system life of aircraft engines. The embedded system provides real-time, inflight monitoring of the engine's thrust, exhaust gas temperature, efficiency, and the speed and time of operation. Based upon this data, the life-estimation algorithm calculates the remaining life of the engine components and uses this data to predict the remaining life of the engine. The calculations are based on the statistical life distribution of the engine components and their relationship to load, speed, temperature, and time.
NASA Technical Reports Server (NTRS)
Hoffman, William C., III
1996-01-01
Determining deterioration characteristics of the Space Shuttle crew escape system pyrotechnic components loaded with hexanitrostilbene would enable us to establish a hardware life-limit for these items, so we could better plan our equipment use and, possibly, extend the useful life of the hardware. We subjected components to accelerated-age environments to determine degradation characteristics and established a hardware life-limit based upon observed and calculated trends. We extracted samples using manufacturing lots currently installed in the Space Shuttle crew escape system and from other NASA programs. Hardware included in the study consisted of various forms and ages of mild detonating fuse, linear shaped charge, and flexible confined detonating cord. The hardware types were segregated into 5 groups. One was subjected to detonation velocity testing for a baseline. Two were first subjected to prolonged 155 F heat exposure, and the other two were first subjected to 255 F, before undergoing detonation velocity testing and/or chromatography analysis. Test results showed no measurable changes in performance to allow a prediction of an end of life given the storage and elevated temperature environments the hardware experiences. Given the lack of a definitive performance trend, coupled with previous tests on post-flight Space Shuttle hardware showing no significant changes in chemical purity or detonation velocity, we recommend a safe increase in the useful life of the hardware to 20 years, from the current maximum limits of 10 and 15 years, depending on the hardware.
Athay, M Michele; Kelley, Susan Douglas; Dew-Reeves, Sarah E
2012-03-01
Youth life satisfaction is a component of subjective well-being, an important part of a strengths-based approach to treatment. This study establishes the psychometric properties of the Brief Multidimensional Students' Life Satisfaction Scale-PTPB Version (BMSLSS-PTPB). The BMSLSS-PTPB showed evidence of construct validity with significant correlations as expected to measures of youth hope and youth symptom severity, and no relationship as expected to youth treatment outcome expectations. A longitudinal analysis was conducted examining the relationship between youth-reported life satisfaction and mental health symptom severity (youth-, caregiver-, and clinician-report) for 334 youth (aged 11-18 years) receiving in-home treatment. Results indicated that life satisfaction consistently increased over the course of treatment but increased faster in youth whose symptom severity, as rated by all reporters, decreased over the course of treatment. Implications, future directions, and limitations of the study are discussed.
Athay, M. Michele; Kelley, Susan Douglas; Dew-Reeves, Sarah E.
2012-01-01
Youth life satisfaction is a component of subjective well-being, an important part of a strengths-based approach to treatment. This study establishes the psychometric properties of the Brief Multidimensional Students’ Life Satisfaction Scale – PTPB version (BMSLSS-PTPB). The BMSLSS-PTPB shows evidence of construct validity with significant correlations as expected to measures of youth hope and youth symptom severity, and no relationship as expected to youth treatment outcome expectations. A longitudinal analysis was conducted examining the relationship between youth-reported life satisfaction and mental health symptom severity (youth, caregiver-, and clinician-report) for 334 youth (aged 11–18 years) receiving in-home treatment. Results indicate that life satisfaction consistently increases over the course of treatment but increases faster in youth whose symptom severity, as rated by all reporters, decreases. Implications, future directions, and limitations of the study are discussed. PMID:22407553
Freedman, Vicki A; Hodgson, Nancy; Lynn, Joanne; Spillman, Brenda C; Waidmann, Timothy; Wilkinson, Anne M; Wolf, Douglas A
2006-01-01
Although the prevalence of late-life disability has been declining, how best to promote further reductions remains unclear. This article develops and then demonstrates an approach for comparing the effects of interventions on the prevalence of late-life disability. We review evidence for three potentially high-impact strategies: physical activity, depression screening and treatment, and fall prevention. Because of the large population at risk for falling, the demonstrated efficacy of multi-component interventions in preventing falls, and the strong links between falls and disability, we conclude that, in the short run, multi-component fall-prevention efforts would likely have a higher impact than either physical activity or depression screening and treatment. However, longer-term comparisons cannot be made based on the current literature and may differ from short-run conclusions, since increases in longevity may temper the influences of these interventions on prevalence. Additional research is needed to evaluate longer-term outcomes of interventions, including effects on length and quality of life. PMID:16953808
Varela-Silva, Maria Inês; Frisancho, A Roberto; Bogin, Barry; Chatkoff, David; Smith, Patricia K; Dickinson, Federico; Winham, Donna
2007-03-01
Nutritional transition, urbanization, and physical inactivity are primary factors responsible for the worldwide epidemic of overweight/obesity (OW/OB). However, these factors fail to explain the epidemic of OW/OB in developing countries and in recent-migrants to developed countries. Among these, OW/OB is associated with short/stunted stature and coexists with undernutrition at much higher rates than is statistically expected. Changes in metabolic pathways toward reduced fat oxidation and increased metabolism of carbohydrate may explain, in part, this phenomenon. Also, intergenerational consequences of malnutrition and poor health of the mothers may lead to impaired phenotypes in their offspring. We propose a novel methodology to assess the history of early life malnutrition by assessing the sitting height ratio of the mothers. The degree of "short leggedness" reflects undernutrition when the mother was an infant/child. Collectively, behavioral, environmental, metabolic and intergenerational components of early life undernutrition may provide a more satisfactory explanation for later life obesity.
Man as the main component of the closed ecological system of the spacecraft or planetary station.
Parin, V V; Adamovich, B A
1968-01-01
Current life-support systems of the spacecraft provide human requirements for food, water and oxygen only. Advanced life-support systems will involve man as their main component and will ensure completely his material and energy requirements. The design of individual components of such systems will assure their entire suitability and mutual control effects. Optimization of the performance of the crew and ecological system, on the basis of the information characterizing their function, demands efficient methods of collection and treatment of the information obtained through wireless recording of physiological parameters and their automatic treatment. Peculiarities of interplanetary missions and planetary stations make it necessary to conform the schedule of physiological recordings with the work-and-rest cycle of the space crew and inertness of components of the ecological system, especially of those responsible for oxygen regeneration. It is rational to model ecological systems and their components, taking into consideration the correction effect of the information on the health conditions and performance of the crewmen. Wide application of physiological data will allow the selection of optimal designs and sharply increase reliability of ecological systems.
Thermal response of integral abutment bridges with mechanically stabilized earth walls.
DOT National Transportation Integrated Search
2013-03-01
The advantages of integral abutment bridges (IABs) include reduced maintenance costs and increased useful life spans. : However, improved procedures are necessary to account for the impacts of cyclic thermal displacements on IAB components, : includi...
ERIC Educational Resources Information Center
Haughey, Laurie
This booklet provides step-by-step guidelines for developing a leadership-through-service-learning component for a school athletic team. It is based on a program called LIFE LINE (Leaders in Football and Education) founded in 1996 as a peer leadership group that would increase team unity and success both on and off the field. The guide summarizes…
Laughton, Alice M; O'Connor, Cian O; Knell, Robert J
2017-11-01
Environmental temperature has important effects on the physiology and life history of ectothermic animals, including investment in the immune system and the infectious capacity of pathogens. Numerous studies have examined individual components of these complex systems, but little is known about how they integrate when animals are exposed to different temperatures. Here, we use the Indian meal moth ( Plodia interpunctella ) to understand how immune investment and disease resistance react and potentially trade-off with other life-history traits. We recorded life-history (development time, survival, fecundity, and body size) and immunity (hemocyte counts, phenoloxidase activity) measures and tested resistance to bacterial ( E. coli ) and viral ( Plodia interpunctella granulosis virus) infection at five temperatures (20-30°C). While development time, lifespan, and size decreased with temperature as expected, moths exhibited different reproductive strategies in response to small changes in temperature. At cooler temperatures, oviposition rates were low but tended to increase toward the end of life, whereas warmer temperatures promoted initially high oviposition rates that rapidly declined after the first few days of adult life. Although warmer temperatures were associated with strong investment in early reproduction, there was no evidence of an associated trade-off with immune investment. Phenoloxidase activity increased most at cooler temperatures before plateauing, while hemocyte counts increased linearly with temperature. Resistance to bacterial challenge displayed a complex pattern, whereas survival after a viral challenge increased with rearing temperature. These results demonstrate that different immune system components and different pathogens can respond in distinct ways to changes in temperature. Overall, these data highlight the scope for significant changes in immunity, disease resistance, and host-parasite population dynamics to arise from small, biologically relevant changes to environmental temperature. In light of global warming, understanding these complex interactions is vital for predicting the potential impact of insect disease vectors and crop pests on public health and food security.
Sensor Based Engine Life Calculation: A Probabilistic Perspective
NASA Technical Reports Server (NTRS)
Guo, Ten-Huei; Chen, Philip
2003-01-01
It is generally known that an engine component will accumulate damage (life usage) during its lifetime of use in a harsh operating environment. The commonly used cycle count for engine component usage monitoring has an inherent range of uncertainty which can be overly costly or potentially less safe from an operational standpoint. With the advance of computer technology, engine operation modeling, and the understanding of damage accumulation physics, it is possible (and desirable) to use the available sensor information to make a more accurate assessment of engine component usage. This paper describes a probabilistic approach to quantify the effects of engine operating parameter uncertainties on the thermomechanical fatigue (TMF) life of a selected engine part. A closed-loop engine simulation with a TMF life model is used to calculate the life consumption of different mission cycles. A Monte Carlo simulation approach is used to generate the statistical life usage profile for different operating assumptions. The probabilities of failure of different operating conditions are compared to illustrate the importance of the engine component life calculation using sensor information. The results of this study clearly show that a sensor-based life cycle calculation can greatly reduce the risk of component failure as well as extend on-wing component life by avoiding unnecessary maintenance actions.
Noncontacting measurement technologies for space propulsion condition monitoring
NASA Technical Reports Server (NTRS)
Randall, M. R.; Barkhoudarian, S.; Collins, J. J.; Schwartzbart, A.
1987-01-01
This paper describes four noncontacting measurement technologies that can be used in a turbopump condition monitoring system. The isotope wear analyzer, fiberoptic deflectometer, brushless torque-meter, and fiberoptic pyrometer can be used to monitor component wear, bearing degradation, instantaneous shaft torque, and turbine blade cracking, respectively. A complete turbopump condition monitoring system including these four technologies could predict remaining component life, thus reducing engine operating costs and increasing reliability.
Togashi, K; Hagiya, K; Osawa, T; Nakanishi, T; Yamazaki, T; Nagamine, Y; Lin, C Y; Matsumoto, S; Aihara, M; Hayasaka, K
2012-08-01
We first sought to clarify the effects of discounted rate, survival rate, and lactation persistency as a component trait of the selection index on net merit, defined as the first five lactation milks and herd life (HL) weighted by 1 and 0.389 (currently used in Japan), respectively, in units of genetic standard deviation. Survival rate increased the relative economic importance of later lactation traits and the first five lactation milk yields during the first 120 months from the start of the breeding scheme. In contrast, reliabilities of the estimated breeding value (EBV) in later lactation traits are lower than those of earlier lactation traits. We then sought to clarify the effects of applying single nucleotide polymorphism (SNP) on net merit to improve the reliability of EBV of later lactation traits to maximize their increased economic importance due to increase in survival rate. Net merit, selection accuracy, and HL increased by adding lactation persistency to the selection index whose component traits were only milk yields. Lactation persistency of the second and (especially) third parities contributed to increasing HL while maintaining the first five lactation milk yields compared with the selection index whose only component traits were milk yields. A selection index comprising the first three lactation milk yields and persistency accounted for 99.4% of net merit derived from a selection index whose components were identical to those for net merit. We consider that the selection index comprising the first three lactation milk yields and persistency is a practical method for increasing lifetime milk yield in the absence of data regarding HL. Applying SNP to the second- and third-lactation traits and HL increased net merit and HL by maximizing the increased economic importance of later lactation traits, reducing the effect of first-lactation milk yield on HL (genetic correlation (rG) = -0.006), and by augmenting the effects of the second- and third-lactation milk yields on HL (rG = 0.118 and 0.257, respectively).
Clinical Interventions for Late-Life Anxious Depression
Diefenbach, Gretchen J; Goethe, John
2006-01-01
Anxiety symptoms are frequently present in patients with late-life depression. The designation “anxious depression” has been used to describe major depressive disorder (MDD) accompanied by clinically significant but subsyndromal anxiety symptoms. MDD may also present comorbid with diagnosable anxiety disorders, although this presentation is less common in late life. Diagnosis of anxious depression in the elderly is complicated by several factors (eg, their tendency to experience and report psychiatric symptoms as somatic illness) and is associated with a more severe clinical presentation, increased risk for suicidal ideation, increased disability, and poorer prognosis. Standard pharmacotherapy for depression may be sufficient but for many patients must be modified or augmented. Psychosocial interventions may also be an important component in the treatment of these patients, although no specific psychosocial treatments have been developed for late-life anxious depression. PMID:18047256
NASA Technical Reports Server (NTRS)
Ko, William L.; Chen, Tony
2006-01-01
The previously developed Ko closed-form aging theory has been reformulated into a more compact mathematical form for easier application. A new equivalent loading theory and empirical loading theories have also been developed and incorporated into the revised Ko aging theory for the prediction of a safe operational life of airborne failure-critical structural components. The new set of aging and loading theories were applied to predict the safe number of flights for the B-52B aircraft to carry a launch vehicle, the structural life of critical components consumed by load excursion to proof load value, and the ground-sitting life of B-52B pylon failure-critical structural components. A special life prediction method was developed for the preflight predictions of operational life of failure-critical structural components of the B-52H pylon system, for which no flight data are available.
Tracking and Control of Gas Turbine Engine Component Damage/Life
NASA Technical Reports Server (NTRS)
Jaw, Link C.; Wu, Dong N.; Bryg, David J.
2003-01-01
This paper describes damage mechanisms and the methods of controlling damages to extend the on-wing life of critical gas turbine engine components. Particularly, two types of damage mechanisms are discussed: creep/rupture and thermo-mechanical fatigue. To control these damages and extend the life of engine hot-section components, we have investigated two methodologies to be implemented as additional control logic for the on-board electronic control unit. This new logic, the life-extending control (LEC), interacts with the engine control and monitoring unit and modifies the fuel flow to reduce component damages in a flight mission. The LEC methodologies were demonstrated in a real-time, hardware-in-the-loop simulation. The results show that LEC is not only a new paradigm for engine control design, but also a promising technology for extending the service life of engine components, hence reducing the life cycle cost of the engine.
Ceramic composites for rocket engine turbines
NASA Technical Reports Server (NTRS)
Herbell, Thomas P.; Eckel, Andrew J.
1991-01-01
The use of ceramic materials in the hot section of the fuel turbopump of advanced reusable rocket engines promises increased performance and payload capability, improved component life and economics, and greater design flexibility. Severe thermal transients present during operation of the Space Shuttle Main Engine (SSME), push metallic components to the limit of their capabilities. Future engine requirements might be even more severe. In phase one of this two-phase program, performance benefits were quantified and continuous fiber reinforced ceramic matrix composite components demonstrated a potential to survive the hostile environment of an advanced rocket engine turbopump.
Ceramic composites for rocket engine turbines
NASA Technical Reports Server (NTRS)
Herbell, Thomas P.; Eckel, Andrew J.
1991-01-01
The use of ceramic materials in the hot section of the fuel turbopump of advanced reusable rocket engines promises increased performance and payload capability, improved component life and economics, and greater design flexibility. Severe thermal transients present during operation of the Space Shuttle Main Engine (SSME), push metallic components to the limit of their capabilities. Future engine requirements might be even more severe. In phase one of this two-phase program, performance benefits were quantified and continuous fiber reinforced ceramic matrix composite components demonstrated a potential to survive the hostile environment of an advaced rocket engine turbopump.
Associations between multidimensional frailty and quality of life among Dutch older people.
Gobbens, Robbert J J; van Assen, Marcel A L M
2017-11-01
To examine the associations between components of physical, psychological and social frailty with quality of life among older people. This cross-sectional study was carried out in a sample of Dutch citizens. A total of 671 people aged 70 years or older completed a web-based questionnaire ('the Senioren Barometer'). This questionnaire contained the Tilburg Frailty Indicator (TFI) for measuring physical, psychological and social frailty, and the WHOQOL-OLD for measuring six quality of life facets (sensory abilities, autonomy, past, present and future activities, social participation, death and dying, intimacy) and quality of life total. Nine of fifteen individual frailty components had an effect on at least one facet of quality of life and quality of life total, after controlling for socio-demographic factors, multimorbidity and the other frailty components. Of these nine components five, two and two refer to physical, psychological and social frailty, respectively. Feeling down was the only frailty component associated with all quality of life facets and quality of life total. Both physical inactivity and lack of social relations were associated with four quality of life facets and quality of life total. This study showed that quality of life in older people is associated with physical, psychological and social frailty components, emphasizing the importance of a multidimensional assessment of frailty. Health care and welfare professionals should in particular pay attention to feeling down, physical inactivity and lack of social relations among older people, because their relation with quality of life seems to be the strongest. Copyright © 2017 Elsevier B.V. All rights reserved.
[Health-related quality of life in Latin American adolescents].
Guedes, Dartagnan Pinto; Villagra Astudillo, Hermán Ariel; Moya Morales, José María; del Campo Vecino, Juan; Pires Júnior, Raymundo
2014-01-01
The objective of the present study was to find out if there are differences in terms of sex, age, or country of origin for the components of health-related quality of life (HRQL) in samples of adolescents from three cities-in Argentina, Brazil, and Chile, respectively-using data collected through an internationally recognized and validated survey questionnaire, KIDSCREEN-52. The KIDSCREEN-52 questionnaire was administered to 1 357 adolescents between 12 and 17 years of age (48.6% of them male) in selected samples in the three countries. Univariate analysis of variation (ANCOVA) was used. Not only sex and age differences, but also differences for each component of HRQL, were found between the three country groups. The data showed significant differences between the three countries for each of the specific components of HRQL. Males scored significantly higher than females in the following components: Physical Well-being (P < 0.001), Psychological Well-being (P = 0.019), Moods and Emotions (P < 0.001), Self-perception (P = 0.001), Autonomy (P < 0.001), and Parent Relations and Home Life (P = 0.008). Furthermore, the average scores for Physical Well-being (P = 0.001), Psychological Well-being (P = 0.001), Self-Perception (P = 0.038), Autonomy (P = 0.001), Parent Relations and Home Life (P = 0.001), School Environment (P = 0.001), and Financial Resources (P = 0.022) showed a significantly declining trend with each advancing year, while average scores for the component Social Acceptance (Bullying) increased significantly with age (P < 0.001). The evidence suggests that interventions in disease prevention and health promotion should be developed for specific target groups, using appropriate actions depending on the sex and age of the adolescents.
Twelve fundamental life histories evolving through allocation-dependent fecundity and survival.
Johansson, Jacob; Brännström, Åke; Metz, Johan A J; Dieckmann, Ulf
2018-03-01
An organism's life history is closely interlinked with its allocation of energy between growth and reproduction at different life stages. Theoretical models have established that diminishing returns from reproductive investment promote strategies with simultaneous investment into growth and reproduction (indeterminate growth) over strategies with distinct phases of growth and reproduction (determinate growth). We extend this traditional, binary classification by showing that allocation-dependent fecundity and mortality rates allow for a large diversity of optimal allocation schedules. By analyzing a model of organisms that allocate energy between growth and reproduction, we find twelve types of optimal allocation schedules, differing qualitatively in how reproductive allocation increases with body mass. These twelve optimal allocation schedules include types with different combinations of continuous and discontinuous increase in reproduction allocation, in which phases of continuous increase can be decelerating or accelerating. We furthermore investigate how this variation influences growth curves and the expected maximum life span and body size. Our study thus reveals new links between eco-physiological constraints and life-history evolution and underscores how allocation-dependent fitness components may underlie biological diversity.
Healthy ageing: the natural consequences of good nutrition-a conference report.
Marsman, D; Belsky, D W; Gregori, D; Johnson, M A; Low Dog, T; Meydani, S; Pigat, S; Sadana, R; Shao, A; Griffiths, J C
2018-05-24
Many countries are witnessing a marked increase in longevity and with this increased lifespan and the desire for healthy ageing, many, however, suffer from the opposite including mental and physical deterioration, lost productivity and quality of life, and increased medical costs. While adequate nutrition is fundamental for good health, it remains unclear what impact various dietary interventions may have on prolonging good quality of life. Studies which span age, geography and income all suggest that access to quality foods, host immunity and response to inflammation/infections, impaired senses (i.e., sight, taste, smell) or mobility are all factors which can limit intake or increase the body's need for specific micronutrients. New clinical studies of healthy ageing are needed and quantitative biomarkers are an essential component, particularly tools which can measure improvements in physiological integrity throughout life, thought to be a primary contributor to a long and productive life (a healthy "lifespan"). A framework for progress has recently been proposed in a WHO report which takes a broad, person-centered focus on healthy ageing, emphasizing the need to better understand an individual's intrinsic capacity, their functional abilities at various life stages, and the impact by mental, and physical health, and the environments they inhabit.
Quality of life in chronic low back pain patients treated with instrumented fusion.
Bentsen, Signe Berit; Hanestad, Berit Rokne; Rustøen, Tone; Wahl, Astrid Klopstad
2008-08-01
The aim of this study was to examine pain and quality of life in a group of preoperative chronic low back pain patients (n = 25) and a group of postoperative chronic low back pain patients (n = 101) treated with instrumented fusion 1-8 years ago. Reduced quality of life is common in chronic low back pain patients and the aim of treatment is to improve quality of life. In the present study, a comparative survey design was used. The McGill Pain Questionnaire and the SF-36 Health Survey were used to examine pain and quality of life. The pre- and postoperative groups did not differ with regard to age, gender, education, other chronic conditions or previous spinal surgery. Compared with the preoperative group, the postoperative group reported significantly lower total, sensory, affective and evaluative pain, used less pain medication (p < 0.05) and reported better scores in all SF-36 components (p < 0.05), except for general health. The effect size was > or =0.8 for all pain components and > or =0.4 for all SF-36 components, except for general health (effect size = 0.009). With regard to long-term follow-up, patients who underwent surgery 5-8 years ago reported better physical role functioning (p < 0.05) compared with those who underwent surgery 1-2 years ago. Results showed that the postoperative group reported significantly less pain and better physical and mental health compared with the preoperative group. However, despite surgery, the postoperative group reported suffering from pain and reduced quality of life. Relevance to clinical practice. Psychosocial interventions focusing on psychosocial consequences of pain are needed to modify the pain experience and increase the quality of life in patients who have undergone this kind of surgery.
Older marijuana users: Life stressors and perceived social support.
Choi, Namkee G; DiNitto, Diana M; Marti, C Nathan
2016-12-01
Given increasing numbers of older-adult marijuana users, this study examined the association of marijuana use and marijuana use disorder with life stressors and perceived social support in the 50+ age group. Data came from the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions (N=14,715 respondents aged 50+). Life stressors were measured with 12 items related to interpersonal, legal, and financial problems and being a crime victim. Perceived social support was measured with the 12-item Interpersonal Support Evaluation List. Using principal component analysis (PCA), we identified four components of life stressors. Linear regression analyses was used to test associations of past-year marijuana use and use disorder with PCA scores of each component and perceived social support. Of the 50+ age group, 3.89% were past-year marijuana users and 0.68% had marijuana use disorder. Marijuana users, especially those with marijuana use disorder (17.54% of past-year users), had high rates of mental and other substance use disorders. Controlling for other potential risk factors for stress, including health status and mental and other substance use disorders, marijuana use and use disorder were still significantly associated with more life stressors and lower perceived social support, possibly from low levels of social integration. A substantial proportion of older-adult marijuana users need help with mental health and substance use problems. Further examination of older marijuana users' life stressors and social support networks may aid in developing more systematic intervention strategies to address needs and reduce marijuana use. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Quality of life and physical activity in an older working-age population.
Puciato, Daniel; Borysiuk, Zbigniew; Rozpara, Michał
2017-01-01
Physical activity can be an effective means of prevention and therapy of many psychosomatic disorders. It can also have a significant impact on the quality of life of older working-age people. The aim of the present study was to assess the relationships between quality of life and physical activity in older working-age people from Wrocław, Poland. The study group comprised 1,013 people, including 565 women and 448 men, aged 55-64 years (59.1±2.9 years). The study took form of a questionnaire survey. The participants assessed their physical activity and quality of life using the International Physical Activity Questionnaire Short Version (IPAQ-SF) and the World Health Organization Quality of Life (WHOQOL-BREF), respectively. The highest mean indices of general quality of life, perceived health status, and quality of life in the physical, psychological, social, and environmental domains were shown by respondents whose intensity of physical activity was the highest. Moreover, the odds of high assessment of overall quality of life increased with respondents' higher levels of physical activity. Quality of life improvement programs should also involve increased physical activity components.
Quality of life and physical activity in an older working-age population
Puciato, Daniel; Borysiuk, Zbigniew; Rozpara, Michał
2017-01-01
Objective Physical activity can be an effective means of prevention and therapy of many psychosomatic disorders. It can also have a significant impact on the quality of life of older working-age people. The aim of the present study was to assess the relationships between quality of life and physical activity in older working-age people from Wrocław, Poland. Materials and methods The study group comprised 1,013 people, including 565 women and 448 men, aged 55–64 years (59.1±2.9 years). The study took form of a questionnaire survey. The participants assessed their physical activity and quality of life using the International Physical Activity Questionnaire Short Version (IPAQ-SF) and the World Health Organization Quality of Life (WHOQOL-BREF), respectively. Results The highest mean indices of general quality of life, perceived health status, and quality of life in the physical, psychological, social, and environmental domains were shown by respondents whose intensity of physical activity was the highest. Moreover, the odds of high assessment of overall quality of life increased with respondents’ higher levels of physical activity. Conclusion Quality of life improvement programs should also involve increased physical activity components. PMID:29042763
Optical Structural Health Monitoring Device
NASA Technical Reports Server (NTRS)
Buckner, Benjamin D.; Markov, Vladimir; Earthman, James C.
2010-01-01
This non-destructive, optical fatigue detection and monitoring system relies on a small and unobtrusive light-scattering sensor that is installed on a component at the beginning of its life in order to periodically scan the component in situ. The method involves using a laser beam to scan the surface of the monitored component. The device scans a laser spot over a metal surface to which it is attached. As the laser beam scans the surface, disruptions in the surface cause increases in scattered light intensity. As the disruptions in the surface grow, they will cause the light to scatter more. Over time, the scattering intensities over the scanned line can be compared to detect changes in the metal surface to find cracks, crack precursors, or corrosion. This periodic monitoring of the surface can be used to indicate the degree of fatigue damage on a component and allow one to predict the remaining life and/or incipient mechanical failure of the monitored component. This wireless, compact device can operate for long periods under its own battery power and could one day use harvested power. The prototype device uses the popular open-source TinyOS operating system on an off-the-shelf Mica2 sensor mote, which allows wireless command and control through dynamically reconfigurable multi-node sensor networks. The small size and long life of this device could make it possible for the nodes to be installed and left in place over the course of years, and with wireless communication, data can be extracted from the nodes by operators without physical access to the devices. While a prototype has been demonstrated at the time of this reporting, further work is required in the system s development to take this technology into the field, especially to improve its power management and ruggedness. It should be possible to reduce the size and sensitivity as well. Establishment of better prognostic methods based on these data is also needed. The increase of surface roughness with fatigue is closely connected to the microstructure of the metal, and ongoing research is seeking to connect this observed evidence of the fatigue state with microstructural theories of fatigue evolution to allow more accurate prognosis of remaining component life. Plans are also being discussed for flight testing, perhaps on NASA s SOFIA platform.
Reliability analysis of different structure parameters of PCBA under drop impact
NASA Astrophysics Data System (ADS)
Liu, P. S.; Fan, G. M.; Liu, Y. H.
2018-03-01
The establishing process of PCBA is modelled by finite element analysis software ABAQUS. Firstly, introduce the Input-G method and the fatigue life under drop impact are introduced and the mechanism of the solder joint failure in the process of drop is analysed. The main reason of solder joint failure is that the PCB component is suffering repeated tension and compression stress during the drop impact. Finally, the equivalent stress and peel stress of different solder joint and plate-level components under different impact acceleration are also analysed. The results show that the reliability of tin-silver copper joint is better than that of tin- lead solder joint, and the fatigue life of solder joint expectancy decrease as the impact pulse amplitude increases.
Schnettler, Berta; Grunert, Klaus G; Lobos, Germán; Miranda-Zapata, Edgardo; Denegri, Marianela; Hueche, Clementina
2018-04-03
To identify mother-adolescent dyad profiles according to food-related parenting practices and to determine differences in diet quality, family meal frequency, life satisfaction, and sociodemographic characteristics. Cross-sectional study. Mothers and children were surveyed in their homes or at schools in Temuco, Chile. A total of 300 mothers (average age, 41.6 years) and their adolescent children (average age, 13.2 years; 48.7% female). Maternal feeding practices using the abbreviated Family Food Behavior Survey (AFFBS), life satisfaction, food-related and family life satisfaction, diet quality, and eating habits. Principal component factor analysis and confirmatory factor analysis were used to verify Family Food Behavior Survey components in mother and adolescent subsamples. Hierarchical cluster analysis was used to identify profiles. Three AFFBS components were detected: maternal control of child snacking behavior, maternal presence during eating, and child involvement in food consumption. Cluster analysis identified 3 mother-adolescent dyad profiles with different food-related parenting practices (P ≤ .001), mother (P ≤ .05) and child (P ≤ .001) diet quality, frequency of shared family meals (P ≤ .001), and mother (P ≤ .001) and child (P ≤ .05) life satisfaction levels. Results indicated that maternal well-being increased with an increased frequency of shared mealtime. Significantly, in contrast to the findings of previous studies, greater control over child eating habits was shown to affect adolescent well-being positively. These findings, among others, may contribute to the development of strategies for improving diet quality, overall well-being, and well-being in the food and family domains for all family members. Copyright © 2018 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.
Fathers matter: male body mass affects life-history traits in a size-dimorphic seabird
Jenouvrier, Stéphanie; Börger, Luca; Weimerskirch, Henri; Ozgul, Arpat
2017-01-01
One of the predicted consequences of climate change is a shift in body mass distributions within animal populations. Yet body mass, an important component of the physiological state of an organism, can affect key life-history traits and consequently population dynamics. Over the past decades, the wandering albatross—a pelagic seabird providing bi-parental care with marked sexual size dimorphism—has exhibited an increase in average body mass and breeding success in parallel with experiencing increasing wind speeds. To assess the impact of these changes, we examined how body mass affects five key life-history traits at the individual level: adult survival, breeding probability, breeding success, chick mass and juvenile survival. We found that male mass impacted all traits examined except breeding probability, whereas female mass affected none. Adult male survival increased with increasing mass. Increasing adult male mass increased breeding success and mass of sons but not of daughters. Juvenile male survival increased with their chick mass. These results suggest that a higher investment in sons by fathers can increase their inclusive fitness, which is not the case for daughters. Our study highlights sex-specific differences in the effect of body mass on the life history of a monogamous species with bi-parental care. PMID:28469021
NASA GRC Fatigue Crack Initiation Life Prediction Models
NASA Technical Reports Server (NTRS)
Arya, Vinod K.; Halford, Gary R.
2002-01-01
Metal fatigue has plagued structural components for centuries, and it remains a critical durability issue in today's aerospace hardware. This is true despite vastly improved and advanced materials, increased mechanistic understanding, and development of accurate structural analysis and advanced fatigue life prediction tools. Each advance is quickly taken advantage of to produce safer, more reliable, more cost effective, and better performing products. In other words, as the envelope is expanded, components are then designed to operate just as close to the newly expanded envelope as they were to the initial one. The problem is perennial. The economic importance of addressing structural durability issues early in the design process is emphasized. Tradeoffs with performance, cost, and legislated restrictions are pointed out. Several aspects of structural durability of advanced systems, advanced materials and advanced fatigue life prediction methods are presented. Specific items include the basic elements of durability analysis, conventional designs, barriers to be overcome for advanced systems, high-temperature life prediction for both creep-fatigue and thermomechanical fatigue, mean stress effects, multiaxial stress-strain states, and cumulative fatigue damage accumulation assessment.
A Primer In Advanced Fatigue Life Prediction Methods
NASA Technical Reports Server (NTRS)
Halford, Gary R.
2000-01-01
Metal fatigue has plagued structural components for centuries, and it remains a critical durability issue in today's aerospace hardware. This is true despite vastly improved and advanced materials, increased mechanistic understanding, and development of accurate structural analysis and advanced fatigue life prediction tools. Each advance is quickly taken advantage of to produce safer, more reliable more cost effective, and better performing products. In other words, as the envelop is expanded, components are then designed to operate just as close to the newly expanded envelop as they were to the initial one. The problem is perennial. The economic importance of addressing structural durability issues early in the design process is emphasized. Tradeoffs with performance, cost, and legislated restrictions are pointed out. Several aspects of structural durability of advanced systems, advanced materials and advanced fatigue life prediction methods are presented. Specific items include the basic elements of durability analysis, conventional designs, barriers to be overcome for advanced systems, high-temperature life prediction for both creep-fatigue and thermomechanical fatigue, mean stress effects, multiaxial stress-strain states, and cumulative fatigue damage accumulation assessment.
NASA GRC Fatigue Crack Initiation Life Prediction Models
NASA Astrophysics Data System (ADS)
Arya, Vinod K.; Halford, Gary R.
2002-10-01
Metal fatigue has plagued structural components for centuries, and it remains a critical durability issue in today's aerospace hardware. This is true despite vastly improved and advanced materials, increased mechanistic understanding, and development of accurate structural analysis and advanced fatigue life prediction tools. Each advance is quickly taken advantage of to produce safer, more reliable, more cost effective, and better performing products. In other words, as the envelope is expanded, components are then designed to operate just as close to the newly expanded envelope as they were to the initial one. The problem is perennial. The economic importance of addressing structural durability issues early in the design process is emphasized. Tradeoffs with performance, cost, and legislated restrictions are pointed out. Several aspects of structural durability of advanced systems, advanced materials and advanced fatigue life prediction methods are presented. Specific items include the basic elements of durability analysis, conventional designs, barriers to be overcome for advanced systems, high-temperature life prediction for both creep-fatigue and thermomechanical fatigue, mean stress effects, multiaxial stress-strain states, and cumulative fatigue damage accumulation assessment.
AGARD/SMP Review Damage Tolerance for Engine Structures. 3. Component Behaviour and Life Management
1990-06-01
Life Management (Revue AGARD/SMP - ToIrance aux Dommages pour les Composants de Moteurs 3. Le Comportement des Composants et la Gestion % de Leur Dur...Structures 3. Component Behaviour and Life Management . (Revue AGARD/SMP - ToI~rance aux Dommages pour les Compos ants de Moteurs 3. Le Comportement...engine parts. The present report includes the papers presented during Workshop Ill which was devoted to Component Behaviour and Life Management . It also
Components of life model in practice.
Mitchell, D; Hicks, M
1995-10-01
This paper attempts to cover the stages recognised as being part of the research process in order to investigate the problem related to the lack of individualised patient care documentation and supporting theoretical framework, which is both understood and accepted by the staff within Accident and Emergency (A & E). With the advent of the United Kingdom Central Council's (UKCC) document Standards of Record Keeping (1993), there is now greater need for a model to be implemented and accepted by those working in the department. The Components of Life model was introduced following a literature search, as this seemed to be a potential solution to the problem, since it emphasises the individual practising self-care activities in order to maintain independence. To initiate staff to the Components of Life model, a half study day was organised on the subject of models of care within A & E. Jones was invited to discuss his approach to A & E nursing care. Subsequently, a draft document relating to nursing care was created using the Components of Life model as a framework. The initial draft was followed with a printed document which was put into use for a trial period of 4 weeks, followed by a review. The review collected both positive and negative comments from the staff, the negative proved to be the most constructive as they served to make improvements within the care plan. Perhaps the most important success as a result of completing this project is that of increased staff enthusiasm and motivation--especially in wanting to make the documentation work.
14 CFR 25.1711 - Component identification: EWIS.
Code of Federal Regulations, 2010 CFR
2010-01-01
... rules, by operating rules, or as a result of the assessment required by § 25.1709, EWIS components...) of this section must remain legible throughout the expected service life of the EWIS component. (d... adverse effect on the performance of that component throughout its expected service life. (e...
NASA Astrophysics Data System (ADS)
Jost, Benjamin; Klein, Marcus; Eifler, Dietmar
This paper focuses on the ductile cast iron EN-GJS-600 which is often used for components of combustion engines. Under service conditions, those components are mechanically loaded at different temperatures. Therefore, this investigation targets at the fatigue behavior of EN-GJS-600 at ambient and elevated temperatures. Light and scanning electron microscopic investigations were done to characterize the sphericity of the graphite as well as the ferrite, pearlite and graphite fraction. At elevated temperatures, the consideration of dynamic strain ageing effects is of major importance. In total strain increase, temperature increase and constant total strain amplitude tests, the plastic strain amplitude, the stress amplitude, the change in temperature and the change in electrical resistance were measured. The measured values depend on plastic deformation processes in the bulk of the specimens and at the interfaces between matrix and graphite. The fatigue behavior of EN-GJS-600 is dominated by cyclic hardening processes. The physically based fatigue life calculation "PHYBALSIT" (SIT = strain increase test) was developed for total strain controlled fatigue tests. Only one temperature increase test is necessary to determine the temperature interval of pronounced dynamic strain ageing effects.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Huang, Runze; Riddle, Matthew; Graziano, Diane
Additive manufacturing (AM) holds great potential for improving materials efficiency, reducing life-cycle impacts, and enabling greater engineering functionality compared to conventional manufacturing (CM), and AM has been increasingly adopted by aircraft component manufacturers for lightweight, cost-effective designs. This study estimates the net changes in life-cycle primary energy and greenhouse gas emissions associated with AM technologies for lightweight metallic aircraft components through the year 2050, to shed light on the environmental benefits of a shift from CM to AM processes in the U.S. aircraft industry. A systems modeling framework is presented, with integrates engineering criteria, life-cycle environmental data, aircraft fleet stockmore » and fuel use models under different AM adoption scenarios. Estimated fleet-wide life-cycle primary energy savings at most reach 70-173 million GJ/year in 2050, with cumulative savings of 1.2–2.8 billion GJ. Associated cumulative GHG emission reductions were estimated at 92.1–215.0 million metric tons. In addition, thousands of tons of aluminum, titanium and nickel alloys could be potentially saved per year in 2050. The results indicate a significant role of AM technologies in helping society meet its long-term energy use and GHG emissions reduction goals, and highlight barriers and opportunities for AM adoption for the aircraft industry.« less
Hood, Glen R; Ott, James R
2017-04-01
Successive generations of bi- and multivoltine species encounter differing biotic and abiotic environments intra-annually. The question of whether selection can independently adjust the relationship between body size and components of reproductive effort within successive generations in response to generation-specific environmental variation is applicable to a diversity of taxa. Herein, we develop a conceptual framework that illustrates increasingly independent life history adjustments between successive generations of taxa exhibiting complex life cycles. We apply this framework to the reproductive biology of the gall-forming insect, Belonocnema treatae (Hymenoptera: Cynipidae). This bivoltine species expresses cyclical parthenogenesis in which alternating sexual and asexual generations develop in different seasons and different environments. We tested the hypotheses that ecological divergence between the alternate generations is accompanied by generational differences in body size, egg size, and egg number and by changes in the relationships between body size and these components of reproductive effort. Increased potential reproductive effort of sexual generation B. treatae is attained by increased body size and egg number (with no trade-off between egg number and egg size) and by a significant increase in the slope of the relationship between body size and potential fecundity. These generation-specific relationships, interpreted in the context of the model framework, suggest that within each generation selection has independently molded the relationships relating body size to potential fecundity and potential reproductive effort in B. treatae. The conceptual framework is broadly applicable to comparisons involving the alternating generations of bi- and multivoltine species.
Grip Strength as an Indicator of Health-Related Quality of Life in Old Age-A Pilot Study.
Musalek, Christina; Kirchengast, Sylvia
2017-11-24
Over the last century life expectancy has increased dramatically nearly all over the world. This dramatic absolute and relative increase of the old aged people component of the population has influenced not only population structure but also has dramatic implications for the individuals and public health services. The aim of the present pilot study was to examine the impact of physical well-being assessed by hand grip strength and social factors estimated by social contact frequency on health-related quality of life among 22 men and 41 women ranging in age between 60 and 94 years. Physical well-being was estimated by hand grip strength, data concerning subjective wellbeing and health related quality of life were collected by personal interviews based on the WHOQOL-BREF questionnaires. Number of offspring and intergenerational contacts were not related significantly to health-related quality of life, while social contacts with non-relatives and hand grip strength in contrast had a significant positive impact on health related quality of life among old aged men and women. Physical well-being and in particular muscle strength-estimated by grip strength-may increase health-related quality of life and is therefore an important source for well-being during old age. Grip strength may be used as an indicator of health-related quality of life.
Guidelines for successful self-scheduling on nursing units.
Russell, Elizabeth; Hawkins, Jenna; Arnold, Kara A
2012-09-01
Self-scheduling programs are an increasingly popular strategy utilized by employers to address the individual and organizational challenges resulting from employee work-life imbalance among the nursing workforce. Certain key components will ensure buy-in and support from staff when self-scheduling programs are developed.
Understanding Undergraduate Professional Development Engagement and Its Impact
ERIC Educational Resources Information Center
Blau, Gary; Snell, Corinne M.
2013-01-01
Professional Development Engagement (PDE) is defined as "the level of undergraduate engagement in professional development." It reflects career-related work preparation for "life after college" and is a distinct externally-focused component of student engagement (SE). The increased college retention and subsequent job placement…
Tsang, Felicia; James, Christol; Kato, Michiko; Myers, Victoria; Ilyas, Irtqa; Tsang, Matthew; Lin, Su-Ju
2015-05-15
Attenuated nutrient signaling extends the life span in yeast and higher eukaryotes; however, the mechanisms are not completely understood. Here we identify the Ssy1-Ptr3-Ssy5 (SPS) amino acid sensing pathway as a novel longevity factor. A null mutation of SSY5 (ssy5Δ) increases replicative life span (RLS) by ∼50%. Our results demonstrate that several NAD(+) homeostasis factors play key roles in this life span extension. First, expression of the putative malate-pyruvate NADH shuttle increases in ssy5Δ cells, and deleting components of this shuttle, MAE1 and OAC1, largely abolishes RLS extension. Next, we show that Stp1, a transcription factor of the SPS pathway, directly binds to the promoter of MAE1 and OAC1 to regulate their expression. Additionally, deletion of SSY5 increases nicotinamide riboside (NR) levels and phosphate-responsive (PHO) signaling activity, suggesting that ssy5Δ increases NR salvaging. This increase contributes to NAD(+) homeostasis, partially ameliorating the NAD(+) deficiency and rescuing the short life span of the npt1Δ mutant. Moreover, we observed that vacuolar phosphatase, Pho8, is partially required for ssy5Δ-mediated NR increase and RLS extension. Together, our studies present evidence that supports SPS signaling is a novel NAD(+) homeostasis factor and ssy5Δ-mediated life span extension is likely due to concomitantly increased mitochondrial and vacuolar function. Our findings may contribute to understanding the molecular basis of NAD(+) metabolism, cellular life span, and diseases associated with NAD(+) deficiency and aging. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.
Better Mental Component of Quality of Life in Amputee
Karami, GR; Ahmadi, Kh; Nejati, V; Masumi, M
2012-01-01
Background: Assessment of quality of life can promote health services. The purpose of this study was evaluation of health related quality of life in lower limbs amputee veterans of Iran. Methods: In the present cross sectional study, we compared 38 lower limbs amputee veterans with 50 normal healthy subjects with SF36 questioner in face-to-face interview. Results: Amputees had significantly lower grade than normal subject did in role physical (P < 0.01) and were better than normal subjects in vitality (P < 0.001) and mental health (P < 0.01). As a whole, amputees have higher in mental summary component of quality of life (P < 0.05) and lower in physical component of quality of life (P < 0.01). Conclusion: Diminishing the demand and improving social support of amputee veterans might be considered as high grade in mental summary component of their quality of life. PMID:23113210
Rancher and farmer quality of life in the midst of energy development in southwest Wyoming
Allen, Leslie; Montag, Jessica; Lyon, Katie; Soileau, Suzanna; Schuster, Rudy
2014-01-01
Quality of life (QOL) is usually defined as a person’s general well-being, and may include individual perceptions of a variety of factors such family, work, finances, local community services, community relationships, surrounding environment, and other important aspects of their life, ultimately leading to life satisfaction. Energy development can have an effect on QOL components for rural residents. Southwest Wyoming is a rural area with a history of ranching and farming which continues today. This area has also seen a “boom” of increasing wind, solar, oil and gas energy developments over the past decade. Wyoming Department of Agriculture, as part of the Wyoming Landscape Conservation Initiative (WLCI), sponsored research to examine the effect of energy development on ranchers’ and farmers’ quality of life.
Castagné, Raphaële; Delpierre, Cyrille; Kelly-Irving, Michelle; Campanella, Gianluca; Guida, Florence; Krogh, Vittorio; Palli, Domenico; Panico, Salvatore; Sacerdote, Carlotta; Tumino, Rosario; Kyrtopoulos, Soterios; Hosnijeh, Fatemeh Saberi; Lang, Thierry; Vermeulen, Roel; Vineis, Paolo; Stringhini, Silvia; Chadeau-Hyam, Marc
2016-04-27
Lower socioeconomic position (SEP) has consistently been associated with poorer health. To explore potential biological embedding and the consequences of SEP experiences from early life to adulthood, we investigate how SEP indicators at different points across the life course may be related to a combination of 28 inflammation markers. Using blood-derived inflammation profiles measured by a multiplex array in 268 participants from the Italian component of the European Prospective Investigation into Cancer and Nutrition cohort, we evaluate the association between early life, young adulthood and later adulthood SEP with each inflammatory markers separately, or by combining them into an inflammatory score. We identified an increased inflammatory burden in participants whose father had a manual occupation, through increased plasma levels of CSF3 (G-CSF; β = 0.29; P = 0.002), and an increased inflammatory score (β = 1.96; P = 0.029). Social mobility was subsequently modelled by the interaction between father's occupation and the highest household occupation, revealing a significant difference between "stable Non-manual" profiles over the life course versus "Manual to Non-manual" profiles (β = 2.38, P = 0.023). Low SEP in childhood is associated with modest increase in adult inflammatory burden; however, the analysis of social mobility suggests a stronger effect of an upward social mobility over the life course.
Hermida, Juan C; Flores-Hernandez, Cesar; Hoenecke, Heinz R; D'Lima, Darryl D
2014-03-01
This study undertook a computational analysis of a wedged glenoid component for correction of retroverted glenoid arthritic deformity to determine whether a wedge-shaped glenoid component design with a built-in correction for version reduces excessive stresses in the implant, cement, and glenoid bone. Recommendations for correcting retroversion deformity are asymmetric reaming of the anterior glenoid, bone grafting of the posterior glenoid, or a glenoid component with posterior augmentation. Eccentric reaming has the disadvantages of removing normal bone, reducing structural support for the glenoid component, and increasing the risk of bone perforation by the fixation pegs. Bone grafting to correct retroverted deformity does not consistently generate successful results. Finite element models of 2 scapulae models representing a normal and an arthritic retroverted glenoid were implanted with a standard glenoid component (in retroversion or neutral alignment) or a wedged component. Glenohumeral forces representing in vivo loading were applied and stresses and strains computed in the bone, cement, and glenoid component. The retroverted glenoid components generated the highest compressive stresses and decreased cyclic fatigue life predictions for trabecular bone. Correction of retroversion by the wedged glenoid component significantly decreased stresses and predicted greater bone fatigue life. The cement volume estimated to survive 10 million cycles was the lowest for the retroverted components and the highest for neutrally implanted glenoid components and for wedged components. A wedged glenoid implant is a viable option to correct severe arthritic retroversion, reducing the need for eccentric reaming and the risk for implant failure. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.
Hot isostatically pressed manufacture of high strength MERL 76 disk and seal shapes
NASA Technical Reports Server (NTRS)
Eng, R. D.; Evans, D. J.
1982-01-01
The feasibility of using MERL 76, an advanced high strength direct hot isostatic pressed powder metallurgy superalloy, as a full scale component in a high technology, long life, commercial turbine engine were demonstrated. The component was a JT9D first stage turbine disk. The JT9D disk rim temperature capability was increased by at least 22 C and the weight of JT9D high pressure turbine rotating components was reduced by at least 35 pounds by replacement of forged Superwaspaloy components with hot isostatic pressed (HIP) MERL 76 components. The process control plan and acceptance criteria for manufacture of MERL 76 HIP consolidated components were generated. Disk components were manufactured for spin/burst rig test, experimental engine tests, and design data generation, which established lower design properties including tensile, stress-rupture, 0.2% creep and notched (Kt = 2.5) low cycle fatigue properties, Sonntag, fatigue crack propagation, and low cycle fatigue crack threshold data. Direct HIP MERL 76, when compared to conventionally forged Superwaspaloy, is demonstrated to be superior in mechanical properties, increased rim temperature capability, reduced component weight, and reduced material cost by at least 30% based on 1980 costs.
Advanced ceramic coating development for industrial/utility gas turbine applications
NASA Technical Reports Server (NTRS)
Andersson, C. A.; Lau, S. K.; Bratton, R. J.; Lee, S. Y.; Rieke, K. L.; Allen, J.; Munson, K. E.
1982-01-01
The effects of ceramic coatings on the lifetimes of metal turbine components and on the performance of a utility turbine, as well as of the turbine operational cycle on the ceramic coatings were determined. When operating the turbine under conditions of constant cooling flow, the first row blades run 55K cooler, and as a result, have 10 times the creep rupture life, 10 times the low cycle fatigue life and twice the corrosion life with only slight decreases in both specific power and efficiency. When operating the turbine at constant metal temperature and reduced cooling flow, both specific power and efficiency increases, with no change in component lifetime. The most severe thermal transient of the turbine causes the coating bond stresses to approach 60% of the bond strengths. Ceramic coating failures was studied. Analytic models based on fracture mechanics theories, combined with measured properties quantitatively assessed both single and multiple thermal cycle failures which allowed the prediction of coating lifetime. Qualitative models for corrosion failures are also presented.
Life Extending Control. [mechanical fatigue in reusable rocket engines
NASA Technical Reports Server (NTRS)
Lorenzo, Carl F.; Merrill, Walter C.
1991-01-01
The concept of Life Extending Control is defined. Life is defined in terms of mechanical fatigue life. A brief description is given of the current approach to life prediction using a local, cyclic, stress-strain approach for a critical system component. An alternative approach to life prediction based on a continuous functional relationship to component performance is proposed. Based on cyclic life prediction, an approach to life extending control, called the Life Management Approach, is proposed. A second approach, also based on cyclic life prediction, called the implicit approach, is presented. Assuming the existence of the alternative functional life prediction approach, two additional concepts for Life Extending Control are presented.
Life extending control: A concept paper
NASA Technical Reports Server (NTRS)
Lorenzo, Carl F.; Merrill, Walter C.
1991-01-01
The concept of Life Extending Control is defined. Life is defined in terms of mechanical fatigue life. A brief description is given of the current approach to life prediction using a local, cyclic, stress-strain approach for a critical system component. An alternative approach to life prediction based on a continuous functional relationship to component performance is proposed.Base on cyclic life prediction an approach to Life Extending Control, called the Life Management Approach is proposed. A second approach, also based on cyclic life prediction, called the Implicit Approach, is presented. Assuming the existence of the alternative functional life prediction approach, two additional concepts for Life Extending Control are presented.
A cross-sectional study regarding the impact of end-stage renal disease on quality of life.
Donciu, Mihaela-Dora; Tasmoc, Alexandra; Dumea, Raluca; Hogas, Simona; Voroneanu, Luminita; Siriopol, Mihaela Daniela; Covic, A
2013-01-01
The number and severity of physical and psychological symptoms reported by chronic hemodialysis (HD) patients are significant and increasing; with a clear need to clarify which symptom intervention is the most needed. Measurements of quality of life (QoL) have shown, for many decades, an impairment of both physical and psychological aspects in both chronic kidney disease (CKD) pre-dialysis and in end stage renal disease (ESRD) patients. This cross-sectional study was conducted assess the quality of life of a Romanian hemodialysis population and the impact of several clinical and biochemical factors. A total of 102 patients (41 males, 61 females) with a mean age of 52.5 +/- 12.0 years, who were treated with HD three times per week in our dialysis center were included in the study. All subjects completed the Short Form Health Survey Questionnaire (SF-36). Clinical and biochemical parameters were extracted from the EUCLID electronic database. Our measurement showed a deteriorated QoL in our population, all of the included subjects presenting with much lower scores in both physical and mental components than the reference values of SF-36. We did not found any statistic significant correlation between hemoglobin (Hgb) levels or dialysis adequacy and different domains of the SF-36. The only significant association was found between age and the physical component of the SF-36, implying that older patients perceive a more degraded quality of life. HD patients experience a great burden from physical and psychological symptoms of the disease, perceiving an important impairment in their quality of life, especially regarding the physical component.
NASA's Evolutionary Xenon Thruster (NEXT) Component Verification Testing
NASA Technical Reports Server (NTRS)
Herman, Daniel A.; Pinero, Luis R.; Sovey, James S.
2009-01-01
Component testing is a critical facet of the comprehensive thruster life validation strategy devised by the NASA s Evolutionary Xenon Thruster (NEXT) program. Component testing to-date has consisted of long-duration high voltage propellant isolator and high-cycle heater life validation testing. The high voltage propellant isolator, a heritage design, will be operated under different environmental condition in the NEXT ion thruster requiring verification testing. The life test of two NEXT isolators was initiated with comparable voltage and pressure conditions with a higher temperature than measured for the NEXT prototype-model thruster. To date the NEXT isolators have accumulated 18,300 h of operation. Measurements indicate a negligible increase in leakage current over the testing duration to date. NEXT 1/2 in. heaters, whose manufacturing and control processes have heritage, were selected for verification testing based upon the change in physical dimensions resulting in a higher operating voltage as well as potential differences in thermal environment. The heater fabrication processes, developed for the International Space Station (ISS) plasma contactor hollow cathode assembly, were utilized with modification of heater dimensions to accommodate a larger cathode. Cyclic testing of five 1/22 in. diameter heaters was initiated to validate these modified fabrication processes while retaining high reliability heaters. To date two of the heaters have been cycled to 10,000 cycles and suspended to preserve hardware. Three of the heaters have been cycled to failure giving a B10 life of 12,615 cycles, approximately 6,000 more cycles than the established qualification B10 life of the ISS plasma contactor heaters.
Sleep Duration and Health-Related Quality of Life in Predialysis CKD.
Sung, Su-Ah; Hyun, Young Youl; Lee, Kyu Beck; Park, Hayne Cho; Chung, Wookyung; Kim, Yeong Hoon; Kim, Yong-Soo; Park, Sue Kyung; Oh, Kook-Hwan; Ahn, Curie
2018-06-07
Sleep duration has been associated with cardiometabolic risk and mortality. The health-related quality of life represents a patient's comprehensive perception of health and is accepted as a health outcome. We examined the relationship between sleep duration and health-related quality of life in predialysis CKD. In this cross-sectional study, data from 1910 adults with CKD enrolled in the Korean Cohort Study for Outcome in Patients with CKD were analyzed. Health-related quality of life was assessed with the physical component summary and mental component summary of the Short Form-36 Health Survey. Low health-related quality of life was defined as a Short Form-36 Health Survey score >1 SD below the mean. Using a generalized additive model and multivariable logistic regression analysis, the relationship between self-reported sleep duration and health-related quality of life was examined. Seven-hour sleepers showed the highest health-related quality of life. We found an inverted U-shaped relationship between sleep duration and health-related quality of life as analyzed by a generalized additive model. In multivariable logistic analysis, short sleepers (≤5 h/d) had lower health-related quality of life (odds ratio, 3.23; 95% confidence interval, 1.86 to 5.60 for the physical component summary; odds ratio, 2.37; 95% confidence interval, 1.43 to 3.94 for the mental component summary), and long sleepers (≥9 h/d) had lower health-related quality of life (odds ratio, 2.80; 95% confidence interval, 1.55 to 5.03 for the physical component summary; odds ratio, 2.08; 95% confidence interval, 1.20 to 3.60 for the mental component summary) compared with 7-hour sleepers. Sleep duration had a significant U-shaped association with low health-related quality of life. These findings suggest that short or long sleep duration is independently associated with low health-related quality of life in adults with CKD. Copyright © 2018 by the American Society of Nephrology.
Functional connectivity in the developing brain: A longitudinal study from 4 to 9 months of age
Damaraju, E.; Caprihan, A.; Lowe, J.R.; Allen, E.A.; Calhoun, V.D.; Phillips, J.P.
2013-01-01
We characterize the development of intrinsic connectivity networks (ICNs) from 4 to 9 months of age with resting state magnetic resonance imaging performed on sleeping infants without sedative medication. Data is analyzed with independent component analysis (ICA). Using both low (30 components) and high (100 components) ICA model order decompositions, we find that the functional network connectivity (FNC) map is largely similar at both 4 and 9 months. However at 9 months the connectivity strength decreases within local networks and increases between more distant networks. The connectivity within the default-mode network, which contains both local and more distant nodes, also increases in strength with age. The low frequency power spectrum increases with age only in the posterior cingulate cortex and posterior default mode network. These findings are consistent with a general developmental pattern of increasing longer distance functional connectivity over the first year of life and raise questions regarding the developmental importance of the posterior cingulate at this age. PMID:23994454
Functional connectivity in the developing brain: a longitudinal study from 4 to 9months of age.
Damaraju, E; Caprihan, A; Lowe, J R; Allen, E A; Calhoun, V D; Phillips, J P
2014-01-01
We characterize the development of intrinsic connectivity networks (ICNs) from 4 to 9months of age with resting state magnetic resonance imaging performed on sleeping infants without sedative medication. Data is analyzed with independent component analysis (ICA). Using both low (30 components) and high (100 components) ICA model order decompositions, we find that the functional network connectivity (FNC) map is largely similar at both 4 and 9months. However at 9months the connectivity strength decreases within local networks and increases between more distant networks. The connectivity within the default-mode network, which contains both local and more distant nodes, also increases in strength with age. The low frequency power spectrum increases with age only in the posterior cingulate cortex and posterior default mode network. These findings are consistent with a general developmental pattern of increasing longer distance functional connectivity over the first year of life and raise questions regarding the developmental importance of the posterior cingulate at this age. © 2013.
Proceedings of the Symposium on Long-Life Hardware for Space
NASA Technical Reports Server (NTRS)
1970-01-01
Two-volume edition of the papers of the symposium is described. It is divided into six sections - parts, materials, management, system testing, component design, and system test. Material presented focuses attention on problems created by the increased complexity of technology and long-term mission requirements.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Uchida, Shinji; Ozaki, Masayori; Suzuki, Keiko
Long-term administration of ({minus})-epigallocatechin 3-O-gallate (EGCG) to mice through drinking water prevented radiation-induced increase of lipid peroxides in liver and significantly prolonged life span after lethal whole-body X-irradiation. The result indicates validity of this green-tea component as an orally active radio-protector of very low toxicity.
NASA Astrophysics Data System (ADS)
Baggett, R.
2004-11-01
Next Generation Electric Propulsion (NGEP) technology development tasks are working towards advancing solar-powered electric propulsion systems and components to levels ready for transition to flight systems. Current tasks within NGEP include NASA's Evolutionary Xenon Thruster (NEXT), Carbon Based Ion Optics (CBIO), NSTAR Extended Life Test (ELT) and low-power Hall Effect thrusters. The growing number of solar electric propulsion options provides reduced cost and flexibility to capture a wide range of Solar System exploration missions. Benefits of electric propulsion systems over state-of-the-art chemical systems include increased launch windows, which reduce mission risk; increased deliverable payload mass for more science; and a reduction in launch vehicle size-- all of which increase the opportunities for New Frontiers and Discovery class missions. The Dawn Discovery mission makes use of electric propulsion for sequential rendezvous with two large asteroids (Vesta then Ceres), something not possible using chemical propulsion. NEXT components and thruster system under development have NSTAR heritage with significant increases in maximum power and Isp along with deep throttling capability to accommodate changes in input power over the mission trajectory. NEXT will produce engineering model system components that will be validated (through qualification-level and integrated system testing) and ready for transition to flight system development. NEXT offers Discovery, New Frontiers, Mars Exploration and outer-planet missions a larger deliverable payload mass and a smaller launch vehicle size. CBIO addresses the need to further extend ion thruster lifetime by using low erosion carbon-based materials. Testing of 30-cm Carbon-Carbon and Pyrolytic graphite grids using a lab model NSTAR thruster are complete. In addition, JPL completed a 1000 hr. life test on 30-cm Carbon-Carbon grids. The NSTAR ELT was a life time qualification test started in 1999 with a goal of 88 kg throughput of Xenon propellant. The test was intentionally terminated in 2003 after accumulating 233 kg throughput. The thruster has been completely disassembled and the conditions of all components documented. Because most of the NSTAR design features have been used in the NEXT thruster, the success of the ELT goes a long way toward qualifying NEXT by similarity Recent mission analyses for Discovery and New Frontiers class missions have also identified potential benefits of low-power, high thrust Hall Effect thrusters. Estimated to be ready for mission implementation by 2008, low-power Hall systems could increase mission capture for electric propulsion by greatly reducing propulsion cost, mass and complexity.
Active Pattern Factor Control for Gas Turbine Engines
NASA Technical Reports Server (NTRS)
May, James E.
1998-01-01
Small variations in fuel/air mixture ratios within gas turbine combustors can result in measurable, and potentially detrimental, exit thermal gradients. Thermal gradients can increase emissions, as well as shorten the design life of downstream turbomachinery, particularly stator vanes. Uniform temperature profiles are usually sought through careful design and manufacturing of related combustor components. However, small componentto-component variations as well as numerous aging effects degrade system performance. To compensate for degraded thermal performance, researchers are investigating active, closed-loop control schemes.
Recent advances in Ni-H2 technology at NASA Lewis Research Center
NASA Technical Reports Server (NTRS)
Gonzalezsanabria, O. D.; Britton, D. L.; Smithrick, J. J.; Reid, M. A.
1986-01-01
The NASA Lewis Research Center has concentrated its efforts on advancing the Ni-H2 system technology for low Earth orbit applications. Component technology as well as the design principles were studied in an effort to understand the system behavior and failure mechanisms in order to increase performance and extend cycle life. The design principles were previously addressed. The component development is discussed, in particular the separator and nickel electrode and how these efforts will advance the Ni-H2 system technology.
ENVIRONMENTAL ANALYSIS OF GASOLINE BLENDING COMPONENTS THROUGH THEIR LIFE CYCLE
The contributions of three major gasoline blending components (reformate, alkylate and cracked gasoline) to potential environmental impacts are assessed. This study estimates losses of the gasoline blending components due to evaporation and leaks through their life cycle, from pe...
NASA Astrophysics Data System (ADS)
Gribovskaya, I. V.; Gladchenko, I. A.; Zinenko, G. K.
Two methods of extracting mineral elements from otherwise deadlock products of a life-support system are presented. We describe first optimum conditions for recovering elements by water extraction from dry wastes of plants, biomass ash, and solid human wastes after passing them through the catalytic furnace; and, second, we describe acid extracts of biogenous elements by 1N and 2N HNO_3 from these products. Ways to use the extracts of elements in plant nutrition are considered in order to increase the extent to which the mineral loop of a life-support system can be closed.
Ceramic Matrix Composites (CMC) Life Prediction Development
NASA Technical Reports Server (NTRS)
Levine, Stanley R.; Verrilli, Michael J.; Thomas, David J.; Halbig, Michael C.; Calomino, Anthony M.; Ellis, John R.; Opila, Elizabeth J.
1990-01-01
Advanced launch systems will very likely incorporate fiber reinforced ceramic matrix composites (CMC) in critical propulsion and airframe components. The use of CMC will save weight, increase operating margin, safety and performance, and improve reuse capability. For reusable and single mission use, accurate life prediction is critical to success. The tools to accomplish this are immature and not oriented toward the behavior of carbon fiber reinforced silicon carbide (C/SiC), the primary system of interest for many applications. This paper describes an approach and progress made to satisfy the need to develop an integrated life prediction system that addresses mechanical durability and environmental degradation.
A real time neural net estimator of fatigue life
NASA Technical Reports Server (NTRS)
Troudet, T.; Merrill, W.
1990-01-01
A neural net architecture is proposed to estimate, in real-time, the fatigue life of mechanical components, as part of the Intelligent Control System for Reusable Rocket Engines. Arbitrary component loading values were used as input to train a two hidden-layer feedforward neural net to estimate component fatigue damage. The ability of the net to learn, based on a local strain approach, the mapping between load sequence and fatigue damage has been demonstrated for a uniaxial specimen. Because of its demonstrated performance, the neural computation may be extended to complex cases where the loads are biaxial or triaxial, and the geometry of the component is complex (e.g., turbopump blades). The generality of the approach is such that load/damage mappings can be directly extracted from experimental data without requiring any knowledge of the stress/strain profile of the component. In addition, the parallel network architecture allows real-time life calculations even for high frequency vibrations. Owing to its distributed nature, the neural implementation will be robust and reliable, enabling its use in hostile environments such as rocket engines. This neural net estimator of fatigue life is seen as the enabling technology to achieve component life prognosis, and therefore would be an important part of life extending control for reusable rocket engines.
NASA Technical Reports Server (NTRS)
Hendricks, Robert C.; Zaretsky, Erwin V.
2001-01-01
Critical component design is based on minimizing product failures that results in loss of life. Potential catastrophic failures are reduced to secondary failures where components removed for cause or operating time in the system. Issues of liability and cost of component removal become of paramount importance. Deterministic design with factors of safety and probabilistic design address but lack the essential characteristics for the design of critical components. In deterministic design and fabrication there are heuristic rules and safety factors developed over time for large sets of structural/material components. These factors did not come without cost. Many designs failed and many rules (codes) have standing committees to oversee their proper usage and enforcement. In probabilistic design, not only are failures a given, the failures are calculated; an element of risk is assumed based on empirical failure data for large classes of component operations. Failure of a class of components can be predicted, yet one can not predict when a specific component will fail. The analogy is to the life insurance industry where very careful statistics are book-kept on classes of individuals. For a specific class, life span can be predicted within statistical limits, yet life-span of a specific element of that class can not be predicted.
The Structure of Self-Perceived Quality of Life of Men and Women Graduate Students.
ERIC Educational Resources Information Center
Aguilar-Gaxiola, Sergio; And Others
Self-perceived quality of life (QOL) was studied using data collected by Carter (1984) on 56 men and 83 women psychology graduate students. Attention was directed to QOL, adjustment, and stress in the study population. Life component satisfaction ratings were multiplied by the importance ascribed to them by the respondents. Life component scores…
NASA Technical Reports Server (NTRS)
Arakere, Nagaraj K.; Swanson, Gregory R.
2000-01-01
High Cycle Fatigue (HCF) induced failures in aircraft gas-turbine engines is a pervasive problem affecting a wide range of components and materials. HCF is currently the primary cause of component failures in gas turbine aircraft engines. Turbine blades in high performance aircraft and rocket engines are increasingly being made of single crystal nickel superalloys. Single-crystal Nickel-base superalloys were developed to provide superior creep, stress rupture, melt resistance and thermomechanical fatigue capabilities over polycrystalline alloys previously used in the production of turbine blades and vanes. Currently the most widely used single crystal turbine blade superalloys are PWA 1480/1493 and PWA 1484. These alloys play an important role in commercial, military and space propulsion systems. PWA1493, identical to PWA1480, but with tighter chemical constituent control, is used in the NASA SSME (Space Shuttle Main Engine) alternate turbopump, a liquid hydrogen fueled rocket engine. Objectives for this paper are motivated by the need for developing failure criteria and fatigue life evaluation procedures for high temperature single crystal components, using available fatigue data and finite element modeling of turbine blades. Using the FE (finite element) stress analysis results and the fatigue life relations developed, the effect of variation of primary and secondary crystal orientations on life is determined, at critical blade locations. The most advantageous crystal orientation for a given blade design is determined. Results presented demonstrates that control of secondary and primary crystallographic orientation has the potential to optimize blade design by increasing its resistance to fatigue crack growth without adding additional weight or cost.
Mountaintop removal and valley fill coal mining has altered the physicochemical landscape of the Central Appalachian region in the U.S. Increased specific conductance and levels of component ions downstream from valley fill sites are toxic to aquatic life and can negatively impa...
Schrempf, Alexandra; Giehr, Julia; Röhrl, Ramona; Steigleder, Sarah; Heinze, Jürgen
2017-04-01
One of the central tenets of life-history theory is that organisms cannot simultaneously maximize all fitness components. This results in the fundamental trade-off between reproduction and life span known from numerous animals, including humans. Social insects are a well-known exception to this rule: reproductive queens outlive nonreproductive workers. Here, we take a step forward and show that under identical social and environmental conditions the fecundity-longevity trade-off is absent also within the queen caste. A change in reproduction did not alter life expectancy, and even a strong enforced increase in reproductive efforts did not reduce residual life span. Generally, egg-laying rate and life span were positively correlated. Queens of perennial social insects thus seem to maximize at the same time two fitness parameters that are normally negatively correlated. Even though they are not immortal, they best approach a hypothetical "Darwinian demon" in the animal kingdom.
Early-Life Nutrition and Neurodevelopment: Use of the Piglet as a Translational Model12
Mudd, Austin T
2017-01-01
Optimal nutrition early in life is critical to ensure proper structural and functional development of infant organ systems. Although pediatric nutrition historically has emphasized research on the relation between nutrition, growth rates, and gastrointestinal maturation, efforts increasingly have focused on how nutrition influences neurodevelopment. The provision of human milk is considered the gold standard in pediatric nutrition; thus, there is interest in understanding how functional nutrients and bioactive components in milk may modulate developmental processes. The piglet has emerged as an important translational model for studying neurodevelopmental outcomes influenced by pediatric nutrition. Given the comparable nutritional requirements and strikingly similar brain developmental patterns between young pigs and humans, the piglet is being used increasingly in developmental nutritional neuroscience studies. The piglet primarily has been used to assess the effects of dietary fatty acids and their accretion in the brain throughout neurodevelopment. However, recent research indicates that other dietary components, including choline, iron, cholesterol, gangliosides, and sialic acid, among other compounds, also affect neurodevelopment in the pig model. Moreover, novel analytical techniques, including but not limited to MRI, behavioral assessments, and molecular quantification, allow for a more holistic understanding of how nutrition affects neurodevelopmental patterns. By combining early-life nutritional interventions with innovative analytical approaches, opportunities abound to quantify factors affecting neurodevelopmental trajectories in the neonate. This review discusses research using the translational pig model with primary emphasis on early-life nutrition interventions assessing neurodevelopment outcomes, while also discussing nutritionally-sensitive methods to characterize brain maturation. PMID:28096130
Structural health monitoring apparatus and methodology
NASA Technical Reports Server (NTRS)
Giurgiutiu, Victor (Inventor); Yu, Lingyu (Inventor); Bottai, Giola Santoni (Inventor)
2011-01-01
Disclosed is an apparatus and methodology for structural health monitoring (SHM) in which smart devices interrogate structural components to predict failure, expedite needed repairs, and thus increase the useful life of those components. Piezoelectric wafer active sensors (PWAS) are applied to or integrated with structural components and various data collected there from provide the ability to detect and locate cracking, corrosion, and disbanding through use of pitch-catch, pulse-echo, electro/mechanical impedance, and phased array technology. Stand alone hardware and an associated software program are provided that allow selection of multiple types of SHM investigations as well as multiple types of data analysis to perform a wholesome investigation of a structure.
Wong, Florence Mei Fung; Sit, Janet Wing Hung; Wong, Eliza Mi Ling; Choi, Kai Chow
2014-12-01
To explore factors associated with health-related quality of life of patients with implantable cardioverter defibrillators. Substantial evidence indicates that implantable cardioverter defibrillator is proven to increase survival rate by terminating life-threatening arrhythmia. However, this device can negatively affect health-related quality of life. Little is known about factors associated with health-related quality of life of patients with implantable cardioverter defibrillators, particularly in Asian population. A transversal descriptive design was used. Data were collected from a convenience sample of 139 adult patients with implantable cardioverter defibrillators from 4 January-30 April 2012 using the structured questionnaires administered by the researcher and medical record reviews. The Short Form-36 Health Survey version 2 was used to measure health-related quality of life. A total of 139 Chinese patients, including 107 (77·0%) males with a mean age of 63·0 (14·6) years, were selected. The physical component summary was relatively lower, whereas the mental component summary was relatively higher than that of the general Hong Kong Chinese population. Multivariable regression analysis revealed gender, self-care dependence, educational level, atrial fibrillation, diabetes mellitus, anxiety and depression significantly associated with physical or mental quality of life. Depression was a common factor affecting physical and mental quality of life. Self-care dependence, atrial fibrillation, diabetes mellitus, depression and anxiety could be improved. Our findings expand existing knowledge on identifying at-risk patients for having lower quality of life, thus allowing development of appropriate interventions targeting risk factors for improving health-related quality of life of patients with implantable cardioverter defibrillator. © 2014 John Wiley & Sons Ltd.
Soto-Rodríguez, Anxela; García-Soidán, José Luís; de Toro-Santos, Manuel; Rodríguez-González, Manuel; Arias-Gómez, M Jesús; Pérez-Fernández, María Reyes
To assess whether an educational intervention in women in perimenopausal age with diabetes mellitus, hypertension and/or dyslipidemia could improve aspects of quality of life and exercise. A randomized clinical trial. physical activity, quality of life and weight in women aged 45-60 years (n = 320) at time 0 and 12 months after surgery. intervention group (IG): 3 interactive workshops on cardiovascular disease prevention and control group (CG): information by mail. The IG obtained better scores on the mental component of quality of life one year later (p < 0.05) and showed a significant increase in physical activity (p < 0.01). GI women maintained their weight while in CG women it increased (p < 0.01). A simple educational intervention in premenopausal women with a cardiovascular risk factor improves aspects of quality of life and of healthy habits such as physical activity. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.
Hernanz, F; Fidalgo, M; Muñoz, P; Noriega, M González; Gómez-Fleitas, M
2016-08-01
Although reduction mammoplasty (RM) is an effective and efficient treatment for symptomatic macromastia, overweight and obese patients who request this treatment are frequently rejected because of selection criteria based on the body mass index. Scientific evidence is inconclusive regarding the increased postoperative complications in obese patients undergoing RM, and there is a lack of adequately designed studies examining the impact of RM on the quality of life of this group of patients. A descriptive cohort study was performed on 37 consecutive obese patients (body mass index > 30 kg/m(2)) undergoing bilateral RM for symptomatic macromastia. Short Form SF-36 quality-of-life questionnaires were completed at interviews a week before surgery and 6 and 18 months after surgery. In addition, 37 women of matching ages, who were companions of patients hospitalized at our short-stay surgery unit, were used as a control group for comparison. Significant differences between repeated measurements on a single sample were assessed using the Wilcoxon signed-rank test. To evaluate these changes, we used effect size by computing Hedges' g corrected. The preoperative SF-36 physical component score was significantly lower than the control group's score (40 vs. 53, p < 0.001). There was no significant difference in the mental component score (45 vs. 49, p = 0.210). Postoperative SF-36 scores were increased with a normalizing effect, as 18 months after surgery only the body pain domain scored lower than the control group scores. According to our results, obese women with symptomatic macromastia undergoing RM exhibited increased quality of life, and this improvement was maintained over time. Level III Evidence. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Component Reliability Testing of Long-Life Sorption Cryocoolers
NASA Technical Reports Server (NTRS)
Bard, S.; Wu, J.; Karlmann, P.; Mirate, C.; Wade, L.
1994-01-01
This paper summarizes ongoing experiments characterizing the ability of critical sorption cryocooler components to achieve highly reliable operation for long-life space missions. Test data obtained over the past several years at JPL are entirely consistent with achieving ten year life for sorption compressors, electrical heaters, container materials, valves, and various sorbent materials suitable for driving 8 to 180 K refrigeration stages. Test results for various compressor systems are reported. Planned future tests necessary to gain a detailed understanding of the sensitivity of cooler performance and component life to operating constraints, design configurations, and fabrication, assembly and handling techniques, are also discussed.
Modeling Oxidation Induced Stresses in Thermal Barrier Coatings
NASA Technical Reports Server (NTRS)
Ferguson, B. L.; Freborg, A. M.; Petrus, G. J.; Brindley, William J.
1998-01-01
The use of thermal barrier coatings (TBC's) in gas turbines has increased dramatically in recent years, due mainly to the need for component protection from ever increasing service temperatures. Oxidation of the bond coat has been identified as an important contributing factor to spallation of the ceramic top coat during service. Additional variables found to influence TBC thermal cycle life include bond coat coefficient of thermal expansion, creep behavior of both the ceramic and bond coat layers, and modulus of elasticity. The purpose of this work was to characterize the effects of oxidation on the stress states within the TBC system, as well as to examine the interaction of oxidation with other factors affecting TBC life.
Effect of blade outlet angle on radial thrust of single-blade centrifugal pump
NASA Astrophysics Data System (ADS)
Nishi, Y.; Fukutomi, J.; Fujiwara, R.
2012-11-01
Single-blade centrifugal pumps are widely used as sewage pumps. However, a large radial thrust acts on a single blade during pump operation because of the geometrical axial asymmetry of the impeller. This radial thrust causes vibrations of the pump shaft, reducing the service life of bearings and shaft seal devices. Therefore, to ensure pump reliability, it is necessary to quantitatively understand the radial thrust and clarify the behavior and generation mechanism. This study investigated the radial thrust acting on two kinds of single-blade centrifugal impellers having different blade outlet angles by experiments and computational fluid dynamics (CFD) analysis. Furthermore, the radial thrust was modeled by a combination of three components, inertia, momentum, and pressure, by applying an unsteady conservation of momentum to this impeller. As a result, the effects of the blade outlet angle on both the radial thrust and the modeled components were clarified. The total head of the impeller with a blade outlet angle of 16 degrees increases more than the impeller with a blade outlet angle of 8 degrees at a large flow rate. In this case, since the static pressure of the circumference of the impeller increases uniformly, the time-averaged value of the radial thrust of both impellers does not change at every flow rate. On the other hand, since the impeller blade loading becomes large, the fluctuation component of the radial thrust of the impeller with the blade outlet angle of 16 degrees increases. If the blade outlet angle increases, the fluctuation component of the inertia component will increase, but the time-averaged value of the inertia component is located near the origin despite changes in the flow rate. The fluctuation component of the momentum component becomes large at all flow rates. Furthermore, although the time-averaged value of the pressure component is almost constant, the fluctuation component of the pressure component becomes large at a large flow rate. In addition to the increase of the fluctuation component of this pressure component, because the fluctuation component of the inertia and momentum components becomes large (as mentioned above), the radial thrust increases at a large flow rate, as is the case for the impeller with a large blade outlet angle.
Castagné, Raphaële; Delpierre, Cyrille; Kelly-Irving, Michelle; Campanella, Gianluca; Guida, Florence; Krogh, Vittorio; Palli, Domenico; Panico, Salvatore; Sacerdote, Carlotta; Tumino, Rosario; Kyrtopoulos, Soterios; Hosnijeh, Fatemeh Saberi; Lang, Thierry; Vermeulen, Roel; Vineis, Paolo; Stringhini, Silvia; Chadeau-Hyam, Marc
2016-01-01
Lower socioeconomic position (SEP) has consistently been associated with poorer health. To explore potential biological embedding and the consequences of SEP experiences from early life to adulthood, we investigate how SEP indicators at different points across the life course may be related to a combination of 28 inflammation markers. Using blood-derived inflammation profiles measured by a multiplex array in 268 participants from the Italian component of the European Prospective Investigation into Cancer and Nutrition cohort, we evaluate the association between early life, young adulthood and later adulthood SEP with each inflammatory markers separately, or by combining them into an inflammatory score. We identified an increased inflammatory burden in participants whose father had a manual occupation, through increased plasma levels of CSF3 (G-CSF; β = 0.29; P = 0.002), and an increased inflammatory score (β = 1.96; P = 0.029). Social mobility was subsequently modelled by the interaction between father’s occupation and the highest household occupation, revealing a significant difference between “stable Non-manual” profiles over the life course versus “Manual to Non-manual” profiles (β = 2.38, P = 0.023). Low SEP in childhood is associated with modest increase in adult inflammatory burden; however, the analysis of social mobility suggests a stronger effect of an upward social mobility over the life course. PMID:27117519
Malpas, Phillipa Jean; Mitchell, Kay
2017-05-01
Rapidly aging populations and increased prevalence of chronic rather than acute illnesses have seen growing public and professional interest in medical decision making at the end of life and greater attention being paid to the factors that influence how individuals make such decisions. This study comprised 2 components: The first, a postal survey, based on the Remmelink questionnaire was sent in May 2013 to 3420 general practitioners (GPs) in New Zealand. Results from this component are reported elsewhere. The second component (reported here) sought information by inviting GPs to ring a free-phone number to be interviewed about their experiences caring for their dying patients. Interviews were recorded then transcribed with identifying information deleted to preserve anonymity. With an aging population, the provision of end-of-life care will increase in general practice. There is no doubt that hospice and specialist palliative care have transformed the quality of care for the dying and their families in New Zealand. However, while respondents in this study seemed realistic about what palliative care can and cannot achieve, patients and their families may have unrealistic expectations of both hospice and palliative medicine. Many GPs appear confused over the legality of the assistance they provide to the terminally ill, concerned that actions such as increasing medication to address refractory symptoms, or stopping food and fluids may put them at risk of legal censure when they foresee that their actions may hasten death.
High temperature coatings for gas turbines
Zheng, Xiaoci Maggie
2003-10-21
Coating for high temperature gas turbine components that include a MCrAlX phase, and an aluminum-rich phase, significantly increase oxidation and cracking resistance of the components, thereby increasing their useful life and reducing operating costs. The aluminum-rich phase includes aluminum at a higher concentration than aluminum concentration in the MCrAlX alloy, and an aluminum diffusion-retarding composition, which may include cobalt, nickel, yttrium, zirconium, niobium, molybdenum, rhodium, cadmium, indium, cerium, iron, chromium, tantalum, silicon, boron, carbon, titanium, tungsten, rhenium, platinum, and combinations thereof, and particularly nickel and/or rhenium. The aluminum-rich phase may be derived from a particulate aluminum composite that has a core comprising aluminum and a shell comprising the aluminum diffusion-retarding composition.
Barwood, Martin J.; Corbett, Jo; Massey, Heather; McMorris, Terry; Tipton, Mike; Wagstaff, Christopher R. D.
2018-01-01
Introduction: Drowning is a leading cause of accidental death. In cold-water, sudden skin cooling triggers the life-threatening cold shock response (CSR). The CSR comprises tachycardia, peripheral vasoconstriction, hypertension, inspiratory gasp, and hyperventilation with the hyperventilatory component inducing hypocapnia and increasing risk of aspirating water to the lungs. Some CSR components can be reduced by habituation (i.e., reduced response to stimulus of same magnitude) induced by 3–5 short cold-water immersions (CWI). However, high levels of acute anxiety, a plausible emotion on CWI: magnifies the CSR in unhabituated participants, reverses habituated components of the CSR and prevents/delays habituation when high levels of anxiety are experienced concurrent to immersions suggesting anxiety is integral to the CSR. Purpose: To examine the predictive relationship that prior ratings of acute anxiety have with the CSR. Secondly, to examine whether anxiety ratings correlated with components of the CSR during immersion before and after induction of habituation. Methods: Forty-eight unhabituated participants completed one (CON1) 7-min immersion in to cold water (15°C). Of that cohort, twenty-five completed four further CWIs that would ordinarily induce CSR habituation. They then completed two counter-balanced immersions where anxiety levels were increased (CWI-ANX) or were not manipulated (CON2). Acute anxiety and the cardiorespiratory responses (cardiac frequency [fc], respiratory frequency [fR], tidal volume [VT], minute ventilation [E]) were measured. Multiple regression was used to identify components of the CSR from the most life-threatening period of immersion (1st minute) predicted by the anxiety rating prior to immersion. Relationships between anxiety rating and CSR components during immersion were assessed by correlation. Results: Anxiety rating predicted the fc component of the CSR in unhabituated participants (CON1; p < 0.05, r = 0.536, r2= 0.190). After habituation immersions (i.e., cohort 2), anxiety rating predicted the fR component of the CSR when anxiety levels were lowered (CON2; p < 0.05, r = 0.566, r2= 0.320) but predicted the fc component of the CSR (p < 0.05, r = 0.518, r2= 0.197) when anxiety was increased suggesting different drivers of the CSR when anxiety levels were manipulated; correlation data supported these relationships. Discussion: Acute anxiety is integral to the CSR before and after habituation. We offer a new integrated model including neuroanatomical, perceptual and attentional components of the CSR to explain these data. PMID:29695988
Barwood, Martin J; Corbett, Jo; Massey, Heather; McMorris, Terry; Tipton, Mike; Wagstaff, Christopher R D
2018-01-01
Introduction: Drowning is a leading cause of accidental death. In cold-water, sudden skin cooling triggers the life-threatening cold shock response (CSR). The CSR comprises tachycardia, peripheral vasoconstriction, hypertension, inspiratory gasp, and hyperventilation with the hyperventilatory component inducing hypocapnia and increasing risk of aspirating water to the lungs. Some CSR components can be reduced by habituation (i.e., reduced response to stimulus of same magnitude) induced by 3-5 short cold-water immersions (CWI). However, high levels of acute anxiety, a plausible emotion on CWI: magnifies the CSR in unhabituated participants, reverses habituated components of the CSR and prevents/delays habituation when high levels of anxiety are experienced concurrent to immersions suggesting anxiety is integral to the CSR. Purpose: To examine the predictive relationship that prior ratings of acute anxiety have with the CSR. Secondly, to examine whether anxiety ratings correlated with components of the CSR during immersion before and after induction of habituation. Methods: Forty-eight unhabituated participants completed one (CON1) 7-min immersion in to cold water (15°C). Of that cohort, twenty-five completed four further CWIs that would ordinarily induce CSR habituation. They then completed two counter-balanced immersions where anxiety levels were increased (CWI-ANX) or were not manipulated (CON2). Acute anxiety and the cardiorespiratory responses (cardiac frequency [ f c ], respiratory frequency [ f R ], tidal volume [ V T ], minute ventilation [ E ]) were measured. Multiple regression was used to identify components of the CSR from the most life-threatening period of immersion (1 st minute) predicted by the anxiety rating prior to immersion. Relationships between anxiety rating and CSR components during immersion were assessed by correlation. Results: Anxiety rating predicted the f c component of the CSR in unhabituated participants (CON1; p < 0.05, r = 0.536, r 2 = 0.190). After habituation immersions (i.e., cohort 2), anxiety rating predicted the f R component of the CSR when anxiety levels were lowered (CON2; p < 0.05, r = 0.566, r 2 = 0.320) but predicted the f c component of the CSR ( p < 0.05, r = 0.518, r 2 = 0.197) when anxiety was increased suggesting different drivers of the CSR when anxiety levels were manipulated; correlation data supported these relationships. Discussion: Acute anxiety is integral to the CSR before and after habituation. We offer a new integrated model including neuroanatomical, perceptual and attentional components of the CSR to explain these data.
Influence of burnout and sleep difficulties on the quality of life among medical students.
Pagnin, Daniel; de Queiroz, Valéria
2015-01-01
This study assessed the influence of burnout dimensions and sleep difficulties on the quality of life among preclinical-phase medical school students. Data were collected from 193 students through their completion of the World Health Organization Quality of Life Instrument, the Maslach Burnout Inventory-Student Survey, the Mini-Sleep Questionnaire, the Social Readjustment Rating Scale, and the Beck Depression Inventory. This survey performed hierarchical multiple regressions to quantify the effects of emotional exhaustion, cynicism, academic efficacy, and sleep difficulties on the physical, psychological, social, and environmental components of an individual's quality of life. The influence of confounding variables, such as gender, stress load, and depressive symptoms, were controlled in the statistical analyses. Physical health decreased when emotional exhaustion and sleep difficulties increased. Psychological well-being also decreased when cynicism and sleep difficulties increased. Burnout and sleep difficulties together explained 22 and 21 % of the variance in the physical and psychological well-being, respectively. On the other hand, physical health, psychological well-being, and social relationships increased when the sense of academic efficacy increased. Physical and psychological well-being are negatively associated with emotional exhaustion, cynicism, and sleep difficulties in students in the early phase of medical school. To improve the quality of life of these students, a significant effort should be directed towards burnout and sleep difficulties.
Space Suit Portable Life Support System Test Bed (PLSS 1.0) Development and Testing
NASA Technical Reports Server (NTRS)
Watts, Carly; Campbell, Colin; Vogel, Matthew; Conger, Bruce
2012-01-01
A multi-year effort has been carried out at NASA-JSC to develop an advanced extra-vehicular activity Portable Life Support System (PLSS) design intended to further the current state of the art by increasing operational flexibility, reducing consumables, and increasing robustness. Previous efforts have focused on modeling and analyzing the advanced PLSS architecture, as well as developing key enabling technologies. Like the current International Space Station Extra-vehicular Mobility Unit PLSS, the advanced PLSS comprises three subsystems required to sustain the crew during extra-vehicular activity including the Thermal, Ventilation, and Oxygen Subsystems. This multi-year effort has culminated in the construction and operation of PLSS 1.0, a test bed that simulates full functionality of the advanced PLSS design. PLSS 1.0 integrates commercial off the shelf hardware with prototype technology development components, including the primary and secondary oxygen regulators, Ventilation Subsystem fan, Rapid Cycle Amine swingbed carbon dioxide and water vapor removal device, and Spacesuit Water Membrane Evaporator heat rejection device. The overall PLSS 1.0 test objective was to demonstrate the capability of the Advanced PLSS to provide key life support functions including suit pressure regulation, carbon dioxide and water vapor removal, thermal control and contingency purge operations. Supplying oxygen was not one of the specific life support functions because the PLSS 1.0 test was not oxygen rated. Nitrogen was used for the working gas. Additional test objectives were to confirm PLSS technology development components performance within an integrated test bed, identify unexpected system level interactions, and map the PLSS 1.0 performance with respect to key variables such as crewmember metabolic rate and suit pressure. Successful PLSS 1.0 testing completed 168 test points over 44 days of testing and produced a large database of test results that characterize system level and component performance. With the exception of several minor anomalies, the PLSS 1.0 test rig performed as expected; furthermore, many system responses trended in accordance with pre-test predictions.
Dietary habits and nutritional status of school aged children in Spain.
Fernández San Juan, P M
2006-01-01
The different dietary habits and nutritional status of Spanish schoolchildren have been analyzed. Nutrition affects health throughout the life cycle, and it is best to begin to prevent harm early on. Habits are formed early in life, and habits are a major determinant of food choice in later life. Two trends in particular are worthy of mention in this regard: the progressive globalisation of the food supply and the increase of food intake such as snacks, soft drinks and fast food, wich tipically apport a significant part of daily diet. In Spain, young people are abandoning the "Mediterranean Diet" in favour of industrial products, full of calories and saturated fatty acids but low in nutritional components, wich is contributing to obesity and rising cholesterol levels. Also, breakfast consumption has been identified as an important factor in the nutritional status of children and in Spain we are observing that an increasing percentage of children are omitting breakfast.
Quantitative genetics of immunity and life history under different photoperiods.
Hammerschmidt, K; Deines, P; Wilson, A J; Rolff, J
2012-05-01
Insects with complex life-cycles should optimize age and size at maturity during larval development. When inhabiting seasonal environments, organisms have limited reproductive periods and face fundamental decisions: individuals that reach maturity late in season have to either reproduce at a small size or increase their growth rates. Increasing growth rates is costly in insects because of higher juvenile mortality, decreased adult survival or increased susceptibility to parasitism by bacteria and viruses via compromised immune function. Environmental changes such as seasonality can also alter the quantitative genetic architecture. Here, we explore the quantitative genetics of life history and immunity traits under two experimentally induced seasonal environments in the cricket Gryllus bimaculatus. Seasonality affected the life history but not the immune phenotypes. Individuals under decreasing day length developed slower and grew to a bigger size. We found ample additive genetic variance and heritability for components of immunity (haemocyte densities, proPhenoloxidase activity, resistance against Serratia marcescens), and for the life history traits, age and size at maturity. Despite genetic covariance among traits, the structure of G was inconsistent with genetically based trade-off between life history and immune traits (for example, a strong positive genetic correlation between growth rate and haemocyte density was estimated). However, conditional evolvabilities support the idea that genetic covariance structure limits the capacity of individual traits to evolve independently. We found no evidence for G × E interactions arising from the experimentally induced seasonality.
Iridium/Rhenium Parts For Rocket Engines
NASA Technical Reports Server (NTRS)
Schneider, Steven J.; Harding, John T.; Wooten, John R.
1991-01-01
Oxidation/corrosion of metals at high temperatures primary life-limiting mechanism of parts in rocket engines. Combination of metals greatly increases operating temperature and longevity of these parts. Consists of two transition-element metals - iridium and rhenium - that melt at extremely high temperatures. Maximum operating temperature increased to 2,200 degrees C from 1,400 degrees C. Increases operating lifetimes of small rocket engines by more than factor of 10. Possible to make hotter-operating, longer-lasting components for turbines and other heat engines.
Rowe, Catherine A; Walker, Kristin L; Britton, Peter C; Hirsch, Jameson K
2013-01-01
Individuals who experience negative life events may be at increased risk for suicidal behavior. Intrapersonal characteristics, such as basic psychological needs, however, may buffer this association. To assess the potential moderating role of overall basic psychological needs, and the separate components of autonomy, competence, and relatedness, on the association between negative life events and suicidal behavior. Our sample of 439 college students (311 females, 71%) completed the following self-report surveys: Life Events Scale, Basic Psychological Needs Scale, Beck Depression Inventory - II, and the Suicide Behaviors Questionnaire-Revised. In support of our hypotheses, negative life events were associated with greater levels of suicidal ideation and attempts, and satisfaction of basic psychological needs, including autonomy, relatedness, and competence, significantly moderated this relationship, over and above the effects of the covariates of age, sex, and depressive symptoms. Suicidal behavior associated with the experience of negative life events is not inevitable. Therapeutically bolstering competence, autonomy, and relatedness may be an important suicide prevention strategy for individuals experiencing life stressors.
Flight Physics for Beginners: Simple Examples of Applying Newton's Laws
ERIC Educational Resources Information Center
Spathopoulos, Vassilis
2011-01-01
Educators are constantly trying to find new ways of motivating their students. In subjects such as mechanics with a strong mathematical component, it is particularly important to devise real-life examples that can increase interest and student excitement. Aircraft flight is a topic that most young people find exciting. It therefore would seem…
Effect of growing location on seed oil composition in the cultivated peanut germplasm collection
USDA-ARS?s Scientific Manuscript database
A particularly important component of seed oils is the content of oleic acid as this fatty acid has several health benefits and contributes to increased oil stability, i.e. longer shelf life. We measured 8846 available accessions of the USDA peanut germplasm collection to gauge the range of variatio...
A review of traditional agroforestry in Micronesia
Harley I. Manner
1993-01-01
For the many Micronesian islands, agroforestry was a sustainable land use system, and an integral component of the traditional subsistence system which provided the people with many of the necessities of life. Given the increasing pressures on limited land resources, the social and environmental problems associated with modern agriculture, particularly its use of...
The Role of Nutritional Aspects in Food Allergy: Prevention and Management.
Mazzocchi, Alessandra; Venter, Carina; Maslin, Kate; Agostoni, Carlo
2017-08-09
The prevalence of food allergy in childhood appears to be increasing in both developed and transitional countries. The aim of this paper is to review and summarise key findings in the prevention and management of food allergy, focusing on the role of dietary components and nutritional habits in the development and optimal functioning of the immune system. Essential fatty acids, zinc and vitamin D are likely to enhance the anti-inflammatory and antioxidative barrier and promote immunologic tolerance. Additionally, nutritional components such as pre- and probiotics represent a novel research approach in the attempt to induce a tolerogenic immune environment. For all these reasons, the traditional avoidance diet has been, in recent years, completely reconsidered. New findings on the protective effect of an increased diversity of food introduced in the first year of life on allergic diseases are consistent with the hypothesis that exposure to a variety of food antigens during early life might play a role in the development of immune tolerance. Accordingly, therapeutic (and even preventive) interventions should be planned on an individual basis.
Sleep, health-related quality of life, and functional outcomes in adults with diabetes.
Chasens, Eileen R; Sereika, Susan M; Burke, Lora E; Strollo, Patrick J; Korytkowski, Mary
2014-11-01
This study explored the association of sleep quality with physical and mental health-related quality of life (HRQoL) and functional outcomes in 116 participants with type 2 diabetes. The study is a secondary analysis of baseline data from a clinical trial that examined treatment of obstructive sleep apnea on physical activity and glucose control. Instruments included the Pittsburgh Sleep Quality Index, Medical Outcomes Short-Form Physical Component and Mental Component Scores, and Functional Outcomes of Sleep Questionnaire. Higher physical HRQoL was significantly associated with better sleep quality and improved functional outcomes of increased activity and productivity. Higher mental HRQoL was associated with improved sleep quality and improved functional outcomes of increased activity, social interactions, vigilance, and productivity. Poor sleep quality was a predictor of decreased functional outcomes while controlling for age, race, education, BMI, marital status and physical and mental HRQoL. Poor sleep quality is associated with negative physical, mental, and functional outcomes in adults with type 2 diabetes. Copyright © 2014 Elsevier Inc. All rights reserved.
Cryogenic Motor Enhancement for the NIRISS Instrument on the James Webb Space Telescope
NASA Astrophysics Data System (ADS)
Aldridge, David; Gentilhomme, Macso; Gibson, Andrew; Cameron, Peter; McColgan, Ashley; Dhanji, Zul; Lambros, Scott; Anderson, Mike
2015-09-01
Initial testing of the JWST NIRISS Dual Wheel Mechanism showed unsatisfactory life from the motors used to drive the individual wheel components. An investigation uncovered that theinternal friction had increased due to wear at the lubricated interface between the motor gearhead planetary gears and the planet gear retaining pins, reducing output torque. Work was undertaken to improve the life of this interface. Several design options were selected for development. A successful redesign was qualified with a larger gearhead, modified to use ball-bearings for planetary gear support. To further enhance life, all internal lubrication was changed to sputtered MoS2. PGM- HT cages were also employed for planetary and motor rotor bearings.
Coatings Extend Life of Engines and Infrastructure
NASA Technical Reports Server (NTRS)
2010-01-01
MesoCoat Inc., of Euclid, Ohio, collaborated with Glenn Research Center to provide thermal barrier coating (TBC) technology, developed by Glenn researcher Dongming Zhu, to enhance the lifespan and performance of engines in U.S. Air Force legacy aircraft. The TBC reduces thermal stresses on engine parts, increasing component life by 50 percent. MesoCoat is also producing metal cladding technology that may soon provide similar life-lengthening benefits for the Nation's infrastructure. Through a Space Act Agreement with Glenn, the company employs the Center's high-density infrared arc lamp system to bond its cladding materials for demonstration prototypes; the coating technology can prevent corrosion on metal beams, pipes, and rebar for up to 100 years.
Huang, Sheng-Miauh; Tai, Chen-Jei; Lin, Kuan-Chia; Tai, Cheng-Jeng; Tseng, Ling-Ming; Chien, Li-Yin
2013-01-01
Studies have rarely compared health outcomes for patients with breast cancer at different treatment stages. The purpose of the study was to compare symptoms and quality of life among patients with breast carcinoma receiving target, chemotherapy, or combined therapy. A longitudinal study was carried out with 57 patients receiving chemotherapy, 30 receiving target therapy, and 34 receiving combined therapy. Data were collected before the start of treatment, at 4 weeks, and at 12 weeks following the start of treatment. Symptom severity and interference were assessed by the M. D. Anderson Symptom Inventory. The physical and mental components of quality of life (physical component score [PCS] and mental component score [MCS]) were assessed using SF-36. There were no significant differences in symptom severity and interference for patients in the 3 therapy groups. The PCSs did not differ significantly according to the therapy group but did decrease significantly after each treatment. Patients receiving target therapy had significantly higher MCSs than did patients receiving chemotherapy, but the MCSs did not differ significantly before and after the treatment. Patients with higher symptom severity and interference had worse PCS and MCS. Patients at all treatment groups had worse physical components quality of life after treatment as compared with before treatment. Patients receiving target therapy had better mental components of quality of life. The mental components of quality of life remained stable during treatment. Nurses should assess the patients' symptoms during treatment and provide timely intervention to optimize their quality of life.
Holistic life-span health outcomes among elite intercollegiate student-athletes.
Sorenson, Shawn C; Romano, Russell; Scholefield, Robin M; Martin, Brandon E; Gordon, James E; Azen, Stanley P; Schroeder, E Todd; Salem, George J
2014-01-01
Competitive sports are recognized as having unique health benefits and risks, and the effect of sports on life-span health among elite athletes has received increasing attention. However, supporting scientific data are sparse and do not represent modern athletes. To assess holistic life-span health and health-related quality-of-life (HRQL) among current and former National Collegiate Athletic Association student-athletes (SAs). Cross-sectional study. A large Division I university. Population-based sample of 496 university students and alumni (age 17-84 years), including SAs and an age-matched and sex-matched nonathlete (NA) control group. Participants completed anonymous, self-report questionnaires. We measured the Short-Form 12 (SF-12) physical and mental component HRQL scores and cumulative lifetime experience and relative risk of treatment for joint, cardiopulmonary, and psychosocial health concerns. Older alumni (age 43+ years) SAs reported greater joint health concerns than NAs (larger joint summary scores; P = .04; Cohen d = 0.69; probability of clinically important difference [pCID] = 77%; treatment odds ratio [OR] = 14.0, 95% confidence interval [CI] = 1.6, 126). Joint health for current and younger alumni SAs was similar to that for NAs. Older alumni reported greater cardiopulmonary health concerns than younger alumni (summary score P < .001; d = 1.05; pCID = 85%; OR = 5.8, 95% CI = 2.0, 16) and current students (P < .001; d = 2.25; pCID >99.5%; OR = 7.1, 95% CI = 3.3, 15), but the risk was similar for SAs and NAs. Current SAs demonstrated evidence of better psychosocial health (summary score P = .006; d = -0.52; pCID = 40%) and mental component HRQL (P = .008; d = 0.50; pCID = 48%) versus NAs but similar psychosocial treatment odds (OR = 0.87, 95% CI = 0.39, 1.9). Psychosocial health and mental component HRQL were similar between alumni SAs and NAs. No differences were observed between SAs and NAs in physical component HRQL. The SAs demonstrated significant, clinically meaningful evidence of greater joint health concerns later in life, comparable cardiopulmonary health, and differences in life-span psychosocial health and HRQL profiles compared with NAs. These data provide timely evidence regarding a compelling public issue and highlight the need for further study of life-span health among modern athletes.
Holistic Life-Span Health Outcomes Among Elite Intercollegiate Student–Athletes
Sorenson, Shawn C.; Romano, Russell; Scholefield, Robin M.; Martin, Brandon E.; Gordon, James E.; Azen, Stanley P.; Schroeder, E. Todd; Salem, George J.
2014-01-01
Context: Competitive sports are recognized as having unique health benefits and risks, and the effect of sports on life-span health among elite athletes has received increasing attention. However, supporting scientific data are sparse and do not represent modern athletes. Objective: To assess holistic life-span health and health-related quality-of-life (HRQL) among current and former National Collegiate Athletic Association student–athletes (SAs). Design: Cross-sectional study. Setting: A large Division I university. Patients or Other Participants: Population-based sample of 496 university students and alumni (age 17–84 years), including SAs and an age-matched and sex-matched nonathlete (NA) control group. Main Outcome Measure(s): Participants completed anonymous, self-report questionnaires. We measured the Short-Form 12 (SF-12) physical and mental component HRQL scores and cumulative lifetime experience and relative risk of treatment for joint, cardiopulmonary, and psychosocial health concerns. Results: Older alumni (age 43+ years) SAs reported greater joint health concerns than NAs (larger joint summary scores; P = .04; Cohen d = 0.69; probability of clinically important difference [pCID] = 77%; treatment odds ratio [OR] = 14.0, 95% confidence interval [CI] = 1.6, 126). Joint health for current and younger alumni SAs was similar to that for NAs. Older alumni reported greater cardiopulmonary health concerns than younger alumni (summary score P < .001; d = 1.05; pCID = 85%; OR = 5.8, 95% CI = 2.0, 16) and current students (P < .001; d = 2.25; pCID >99.5%; OR = 7.1, 95% CI = 3.3, 15), but the risk was similar for SAs and NAs. Current SAs demonstrated evidence of better psychosocial health (summary score P = .006; d = −0.52; pCID = 40%) and mental component HRQL (P = .008; d = 0.50; pCID = 48%) versus NAs but similar psychosocial treatment odds (OR = 0.87, 95% CI = 0.39, 1.9). Psychosocial health and mental component HRQL were similar between alumni SAs and NAs. No differences were observed between SAs and NAs in physical component HRQL. Conclusions: The SAs demonstrated significant, clinically meaningful evidence of greater joint health concerns later in life, comparable cardiopulmonary health, and differences in life-span psychosocial health and HRQL profiles compared with NAs. These data provide timely evidence regarding a compelling public issue and highlight the need for further study of life-span health among modern athletes. PMID:25117874
Lahmek, Pierre; Berlin, Ivan; Michel, Laurent; Berghout, Chafia; Meunier, Nadine; Aubin, Henri-Jean
2009-01-01
Background: To investigate the improvement in quality of life (QoL) of alcohol-dependent patients during a 3-week inpatient withdrawal programme, and to identify the sociodemographic, clinical and alcohol-related variables associated with baseline QoL on admission and with improvement of QoL during residential treatment. Methods: This prospective, observational study included 414 alcohol-dependent patients, hospitalised for a period of 3 weeks. QoL was measured on admission and at discharge using the French version of the Medical Outcome Study SF-36. The mean scores for each dimension and for the Physical and Mental Component Summary scores were calculated. Results: The mean scores per dimension and the mean Physical and Mental Component Summary scores were significantly lower on admission than at discharge; the lowest scores being observed for social functioning and role limitations due to emotional problems. At discharge, the mean scores per dimension were similar to those observed in the French general population. Female gender, age >45 years, living alone, working as a labourer or employee, somatic comorbidity, and the existence of at least five criteria for alcohol dependence according to the DSM-IV classification were associated with a low Physical Component Summary score on admission; psychiatric comorbidity, the presence of at least five DSM-IV dependence criteria, smoking and suicidality were associated with a low Mental Component Summary score on admission. The increase in Physical and Mental Component Summary scores during hospitalisation was more marked when the initial scores were low. Apart from the initial score, the greatest improvement in Physical Component Summary score was seen in patients with a high alcohol intake and in those without a somatic comorbidity; the increase in Mental Component Summary score was greatest in patients without psychotic symptoms and in those who abused or were dependent on illegal drugs. Conclusion: QoL improvement after a residential treatment was related to low QoL scores at admission. Improvement in physical component of QoL was related to baseline alcohol intake and good somatic status. Improvement in mental component of QoL was related to other drugs abuse/dependence. PMID:19461935
Lahmek, Pierre; Berlin, Ivan; Michel, Laurent; Berghout, Chafia; Meunier, Nadine; Aubin, Henri-Jean
2009-05-18
To investigate the improvement in quality of life (QoL) of alcohol-dependent patients during a 3-week inpatient withdrawal programme, and to identify the sociodemographic, clinical and alcohol-related variables associated with baseline QoL on admission and with improvement of QoL during residential treatment. This prospective, observational study included 414 alcohol-dependent patients, hospitalised for a period of 3 weeks. QoL was measured on admission and at discharge using the French version of the Medical Outcome Study SF-36. The mean scores for each dimension and for the Physical and Mental Component Summary scores were calculated. The mean scores per dimension and the mean Physical and Mental Component Summary scores were significantly lower on admission than at discharge; the lowest scores being observed for social functioning and role limitations due to emotional problems. At discharge, the mean scores per dimension were similar to those observed in the French general population. Female gender, age > 45 years, living alone, working as a labourer or employee, somatic comorbidity, and the existence of at least five criteria for alcohol dependence according to the DSM-IV classification were associated with a low Physical Component Summary score on admission; psychiatric comorbidity, the presence of at least five DSM-IV dependence criteria, smoking and suicidality were associated with a low Mental Component Summary score on admission. The increase in Physical and Mental Component Summary scores during hospitalisation was more marked when the initial scores were low. Apart from the initial score, the greatest improvement in Physical Component Summary score was seen in patients with a high alcohol intake and in those without a somatic comorbidity; the increase in Mental Component Summary score was greatest in patients without psychotic symptoms and in those who abused or were dependent on illegal drugs. QoL improvement after a residential treatment was related to low QoL scores at admission. Improvement in physical component of QoL was related to baseline alcohol intake and good somatic status. Improvement in mental component of QoL was related to other drugs abuse/dependence.
Moylan, Steven; Jacka, Felice N; Pasco, Julie A; Berk, Michael
2013-01-01
Multiple studies have demonstrated an association between cigarette smoking and increased anxiety symptoms or disorders, with early life exposures potentially predisposing to enhanced anxiety responses in later life. Explanatory models support a potential role for neurotransmitter systems, inflammation, oxidative and nitrosative stress, mitochondrial dysfunction, neurotrophins and neurogenesis, and epigenetic effects, in anxiety pathogenesis. All of these pathways are affected by exposure to cigarette smoke components, including nicotine and free radicals. This review critically examines and summarizes the literature exploring the role of these systems in increased anxiety and how exposure to cigarette smoke may contribute to this pathology at a biological level. Further, this review explores the effects of cigarette smoke on normal neurodevelopment and anxiety control, suggesting how exposure in early life (prenatal, infancy, and adolescence) may predispose to higher anxiety in later life. A large heterogenous literature was reviewed that detailed the association between cigarette smoking and anxiety symptoms and disorders with structural brain changes, inflammation, and cell-mediated immune markers, markers of oxidative and nitrosative stress, mitochondrial function, neurotransmitter systems, neurotrophins and neurogenesis. Some preliminary data were found for potential epigenetic effects. The literature provides some support for a potential interaction between cigarette smoking, anxiety symptoms and disorders, and the above pathways; however, limitations exist particularly in delineating causative effects. The literature also provides insight into potential effects of cigarette smoke, in particular nicotine, on neurodevelopment. The potential treatment implications of these findings are discussed in regards to future therapeutic targets for anxiety. The aforementioned pathways may help mediate increased anxiety seen in people who smoke. Further research into the specific actions of nicotine and other cigarette components on these pathways, and how these pathways interact, may provide insights that lead to new treatment for anxiety and a greater understanding of anxiety pathogenesis. PMID:23785661
Srivastava, Alok Mani; Setlur, Anant Achyut; Comanzo, Holly Ann; Devitt, John William; Ruud, James Anthony; Brewer, Luke Nathaniel
2004-05-04
An apparatus for determining past-service conditions and/or remaining useful life of a component of a combustion engine and/or a thermal barrier coating ("TBC") of the component comprises a radiation source that provides the exciting radiation to the TBC to excite a photoluminescent ("PL") material contained therein, a radiation detector for detecting radiation emitted by the PL material, and means for relating a characteristic of an emission spectrum of the PL material to the amount of a crystalline phase in the TBC, thereby inferring the past-service conditions or the remaining useful life of the component or the TBC.
A review of recent activities in the NASA CELSS program
NASA Technical Reports Server (NTRS)
Macelroy, R. D.; Tremor, J.; Smernoff, D. T.; Knott, W.; Prince, R. P.
1987-01-01
A CELSS (Controlled Ecological Life Support System) is a device that utilizes photosynthetic organisms and light energy to regenerate waste materials into oxygen and food for a crew in space. The results of studies with the CELSS program suggest that a bioregenerative life support system is a useful and effective method of regenerating consumable materials for crew sustenance. The data suggests that the operation of a CELSS in space is practical if plants can be made to behave predictably in the space environment. Much of the work centers on the biological components of the CELSS system. Ways of achieving high efficiency and long term stability of all components of the system are examined. Included are explorations of the conversion of nonedible cellulose to edible materials, nitrogen fixation by biological and chemical methods, and methods of waste processing. A description is provided of the extent to which a bioregenerative life support system can meet the constraints of the space environment, and the degree is assessed to which system efficiency and stability can be increased during the next decade.
Couture, Éva Marjorie; Chouinard, Maud-Christine; Fortin, Martin; Hudon, Catherine
2017-07-06
Although health literacy and quality of life are important concepts in health care, the link between them is unclear, especially for a population of frequent users of health care services with chronic diseases. Low health literacy is a common problem that has been linked to several negative health outcomes. Quality of life is an important health outcome in patient-centered care. Frequent users of health care services are a vulnerable population that deserves attention due to high costs and negative outcomes such as lower quality of life and higher mortality. The objective of this study was to examine the relationship between health literacy and the physical and mental components of quality of life among frequent users of health care services with chronic diseases. This study presents the cross-sectional analysis of data collected through the V1SAGES project, a randomized controlled trial on the effectiveness of a case management intervention in primary care in Quebec, Canada. Participants (n = 247) were frequent users of health care services presenting at least one chronic condition. Health literacy was measured by the Newest Vital Sign (NVS), and the physical and mental components of quality of life were evaluated by the Short Form Health Survey Version 2 (SF-12v2). The association between health literacy (independent variable) and the physical and mental components of quality of life was examined using biserial correlation. No association was found between health literacy and quality of life (physical component: r = 0.108, ρ = 0.11; mental component: r = 0.147, ρ = 0.15). This study suggests that there is no relationship between health literacy and the physical and mental components of quality of life among frequent users of health care services. NCT01719991 . Registered October 25, 2012.
Partial discharge testing under direct voltage conditions
NASA Technical Reports Server (NTRS)
Bever, R. S.; Westrom, J. L.
1982-01-01
DC partial discharge (PD) (corona) testing is performed using a multichannel analyzer for pulse storing, and data is collected during increase of voltage and at quiescent voltage levels. Thus high voltage ceramic disk capacitors were evaluated by obtaining PD data interspersed during an accelerated life test. Increased PD activity was found early in samples that later failed catastrophically. By this technique, trends of insulation behavior are revealed sensitively and nondestructively in high voltage dc components.
Longitudinal associations between resilience and quality of life in eating disorders.
Calvete, Esther; Las Hayas, Carlota; Gómez Del Barrio, Andrés
2018-01-01
This study examined the longitudinal reciprocal associations between resilience factors, quality of life (QoL) domains, and symptoms of eating disorders (EDs). Hypotheses included predictive paths from resilience factors of "acceptance of self and life" and "personal competence" to increased QoL and predictive paths from previous levels of QoL to resilience. A total of 184 patients with EDs (mean age = 29.55, SD = 9.17, 94.8% women) completed measures of resilience, QoL, and EDs symptoms over three waves spaced six month apart. Hypotheses were tested by path analysis. Resilience factors predicted improvements in psychological health and social relationship domains of QoL and a reduction of ED symptoms over time. In addition, psychological health increased acceptance of self and life consistently over time, whereas physical health increased the competence component of resilience. The relationships between resilience factors and QoL are reciprocal, with several mediational paths. A spiral of recursive influences between resilience factors and QoL can take place in people with EDs. This possibility offers new perspectives to understanding the process of recovery in patients with ED. Copyright © 2017 Elsevier B.V. All rights reserved.
Reliability Issues in Stirling Radioisotope Power Systems
NASA Technical Reports Server (NTRS)
Schreiber, Jeffrey; Shah, Ashwin
2005-01-01
Stirling power conversion is a potential candidate for use in a Radioisotope Power System (RPS) for space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced requirement of radioactive material. Reliability of an RPS that utilizes Stirling power conversion technology is important in order to ascertain long term successful performance. Owing to long life time requirement (14 years), it is difficult to perform long-term tests that encompass all the uncertainties involved in the design variables of components and subsystems comprising the RPS. The requirement for uninterrupted performance reliability and related issues are discussed, and some of the critical areas of concern are identified. An overview of the current on-going efforts to understand component life, design variables at the component and system levels, and related sources and nature of uncertainties are also discussed. Current status of the 110 watt Stirling Radioisotope Generator (SRG110) reliability efforts is described. Additionally, an approach showing the use of past experience on other successfully used power systems to develop a reliability plan for the SRG110 design is outlined.
Reliability Issues in Stirling Radioisotope Power Systems
NASA Technical Reports Server (NTRS)
Shah, Ashwin R.; Schreiber, Jeffrey G.
2004-01-01
Stirling power conversion is a potential candidate for use in a Radioisotope Power System (RPS) for space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced requirement of radioactive material. Reliability of an RPS that utilizes Stirling power conversion technology is important in order to ascertain long term successful performance. Owing to long life time requirement (14 years), it is difficult to perform long-term tests that encompass all the uncertainties involved in the design variables of components and subsystems comprising the RPS. The requirement for uninterrupted performance reliability and related issues are discussed, and some of the critical areas of concern are identified. An overview of the current on-going efforts to understand component life, design variables at the component and system levels, and related sources and nature of uncertainties are also discussed. Current status of the 110 watt Stirling Radioisotope Generator (SRG110) reliability efforts is described. Additionally, an approach showing the use of past experience on other successfully used power systems to develop a reliability plan for the SRG110 design is outlined.
Sprangers, Mirjam AG; Schwartz, Carolyn E
2008-01-01
The field of health-related quality of life (HRQOL) could benefit from a broadening of perspectives to include recent advancements in research on adaptation, positive psychology, and genetics. These advances shed new light on the extent to which HRQOL is changeable or fixed. The objective of this paper is to integrate these insights and to discuss their implications for HRQOL research. We describe the Hedonic Treadmill theory, which asserts that positive events only temporarily affect happiness since people quickly return to hedonic neutrality. New empirical evidence suggests important revisions of this theory, providing a more optimistic picture of the possibility for change. Advances in positive psychology show that relatively simple interventions have the power to induce a sustainable increase in levels of happiness. Finally, a small but growing number of studies have found independent genetic influences in well-being, life satisfaction, perceived health, and even HRQOL. Given the increasing empirical evidence that HRQOL can be sustainably enhanced and is in part genetically determined, it may be useful to consider HRQOL as a concept that has state (environmental) and trait (genetic) components. This distinction will allow us to explore new pathways of improving theory, methods, and clinical practice. The overarching novel questions concern the extent to which HRQOL components are environmentally or genetically determined, and which factors lead to lasting improvement. This distinction begs for new research approaches, such as time-sampling techniques and interdisciplinary research investigating the genetic variants of HRQOL. Distinguishing between those aspects that are amenable to change from those that are relatively fixed and stable will help better target specific support interventions. PMID:18976504
Transmission overhaul estimates for partial and full replacement at repair
NASA Technical Reports Server (NTRS)
Savage, M.; Lewicki, D. G.
1991-01-01
Timely transmission overhauls increase in-flight service reliability greater than the calculated design reliabilities of the individual aircraft transmission components. Although necessary for aircraft safety, transmission overhauls contribute significantly to aircraft expense. Predictions of a transmission's maintenance needs at the design stage should enable the development of more cost effective and reliable transmissions in the future. The frequency is estimated of overhaul along with the number of transmissions or components needed to support the overhaul schedule. Two methods based on the two parameter Weibull statistical distribution for component life are used to estimate the time between transmission overhauls. These methods predict transmission lives for maintenance schedules which repair the transmission with a complete system replacement or repair only failed components of the transmission. An example illustrates the methods.
Prognostics for Electronics Components of Avionics Systems
NASA Technical Reports Server (NTRS)
Celaya, Jose R.; Saha, Bhaskar; Wysocki, Philip F.; Goebel, Kai F.
2009-01-01
Electronics components have and increasingly critical role in avionics systems and for the development of future aircraft systems. Prognostics of such components is becoming a very important research filed as a result of the need to provide aircraft systems with system level health management. This paper reports on a prognostics application for electronics components of avionics systems, in particular, its application to the Isolated Gate Bipolar Transistor (IGBT). The remaining useful life prediction for the IGBT is based on the particle filter framework, leveraging data from an accelerated aging tests on IGBTs. The accelerated aging test provided thermal-electrical overstress by applying thermal cycling to the device. In-situ state monitoring, including measurements of the steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.
Towards Prognostics for Electronics Components
NASA Technical Reports Server (NTRS)
Saha, Bhaskar; Celaya, Jose R.; Wysocki, Philip F.; Goebel, Kai F.
2013-01-01
Electronics components have an increasingly critical role in avionics systems and in the development of future aircraft systems. Prognostics of such components is becoming a very important research field as a result of the need to provide aircraft systems with system level health management information. This paper focuses on a prognostics application for electronics components within avionics systems, and in particular its application to an Isolated Gate Bipolar Transistor (IGBT). This application utilizes the remaining useful life prediction, accomplished by employing the particle filter framework, leveraging data from accelerated aging tests on IGBTs. These tests induced thermal-electrical overstresses by applying thermal cycling to the IGBT devices. In-situ state monitoring, including measurements of steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.
Pyykkönen, Antti-Jussi; Räikkönen, Katri; Tuomi, Tiinamaija; Eriksson, Johan G; Groop, Leif; Isomaa, Bo
2010-02-01
Stress may play a role in the pathogenesis of the metabolic syndrome. However, the scant evidence available is not population-based, restricting the external validity of the findings. Our aim was to test associations between stressful life events, their accumulation, and the metabolic syndrome in a large population-based cohort. We also tested associations between stress and the individual components related to the metabolic syndrome. This was a population-based, random sample of 3,407 women and men aged 18-78 years residing in Western Finland. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III and International Diabetes Federation criteria. The severity of 15 stressful life events pertaining to finance, work, social relationships, health, and housing was self-rated. In comparison with subjects not reporting any extremely stressful life events, those reporting work- or finance-related events had an increased odds for having the metabolic syndrome. The risk was further increased according to accumulation of stressful finance-related events and to having at least three stressful life events in any of the life domains assessed. Accumulation of stressful life events was associated with insulin resistance, obesity, and triglycerides. The associations were not confounded by sex, age, lifestyle, or family history of diabetes. Life events perceived as stressful, particularly those related to finance and work, may be a signal for poor metabolic health.
Nondestructive Characterization Techniques Used for Ceramic Matrix Composite Life Determination
NASA Technical Reports Server (NTRS)
Effinger, Michael; Koenig, John; Ellingson, Bill; Spohnholtz, Todd
2000-01-01
Recent results indicate that the specific damping capacity and resonant frequency measurements taken periodically during a component's lifetime is able to quantify the mechanical fatigue of CMCS. This gives hope for the potential of determining the actual and residual life of CMC materials using a combination of nondestructive techniques. If successful, then this new paradigm for life prediction of CMCs could revolutionize the approach for designing and servicing CMC components, thereby significantly reducing costs for design, development, health monitoring, and maintenance of CMC components and systems. The Nondestructive Characterization (NDC) life prediction approach would complement life prediction using micromechanics and continuum finite element models. This paper reports on the initial concept of NDC life prediction, a review of the C/SiC blisk damping data, and how changes in the specific damping capacity & ultrasonic elastic modulus data have established the concept as a possibility.
Recent Advances in Nanotechnology for Diabetes Treatment
DiSanto, Rocco Michael; Subramanian, Vinayak; Gu, Zhen
2015-01-01
Nanotechnology in diabetes research has facilitated the development of novel glucose measurement and insulin delivery modalities which hold the potential to dramatically improve quality of life for diabetics. Recent progress in the field of diabetes research at its interface with nanotechnology is our focus. In particular, we examine glucose sensors with nanoscale components including metal nanoparticles and carbon nanostructures. The addition of nanoscale components commonly increases glucose sensor sensitivity, temporal response, and can lead to sensors which facilitate continuous in vivo glucose monitoring. Additionally, we survey nanoscale approaches to “closed-loop” insulin delivery strategies which automatically release insulin in response to fluctuating blood glucose levels. “Closing the loop” between blood glucose level (BGL) measurements and insulin administration by removing the requirement of patient action holds the potential to dramatically improve the health and quality of life of diabetics. Advantages and limitations of current strategies, as well as future opportunities and challenges are also discussed. PMID:25641955
NEXT Thruster Component Verification Testing
NASA Technical Reports Server (NTRS)
Pinero, Luis R.; Sovey, James S.
2007-01-01
Component testing is a critical part of thruster life validation activities under NASA s Evolutionary Xenon Thruster (NEXT) project testing. The high voltage propellant isolators were selected for design verification testing. Even though they are based on a heritage design, design changes were made because the isolators will be operated under different environmental conditions including temperature, voltage, and pressure. The life test of two NEXT isolators was therefore initiated and has accumulated more than 10,000 hr of operation. Measurements to date indicate only a negligibly small increase in leakage current. The cathode heaters were also selected for verification testing. The technology to fabricate these heaters, developed for the International Space Station plasma contactor hollow cathode assembly, was transferred to Aerojet for the fabrication of the NEXT prototype model ion thrusters. Testing the contractor-fabricated heaters is necessary to validate fabrication processes for high reliability heaters. This paper documents the status of the propellant isolator and cathode heater tests.
CARES/Life Ceramics Durability Evaluation Software Enhanced for Cyclic Fatigue
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Powers, Lynn M.; Janosik, Lesley A.
1999-01-01
The CARES/Life computer program predicts the probability of a monolithic ceramic component's failure as a function of time in service. The program has many features and options for materials evaluation and component design. It couples commercial finite element programs--which resolve a component's temperature and stress distribution--to reliability evaluation and fracture mechanics routines for modeling strength-limiting defects. The capability, flexibility, and uniqueness of CARES/Life have attracted many users representing a broad range of interests and has resulted in numerous awards for technological achievements and technology transfer. Recent work with CARES/Life was directed at enhancing the program s capabilities with regards to cyclic fatigue. Only in the last few years have ceramics been recognized to be susceptible to enhanced degradation from cyclic loading. To account for cyclic loads, researchers at the NASA Lewis Research Center developed a crack growth model that combines the Power Law (time-dependent) and the Walker Law (cycle-dependent) crack growth models. This combined model has the characteristics of Power Law behavior (decreased damage) at high R ratios (minimum load/maximum load) and of Walker law behavior (increased damage) at low R ratios. In addition, a parameter estimation methodology for constant-amplitude, steady-state cyclic fatigue experiments was developed using nonlinear least squares and a modified Levenberg-Marquardt algorithm. This methodology is used to give best estimates of parameter values from cyclic fatigue specimen rupture data (usually tensile or flexure bar specimens) for a relatively small number of specimens. Methodology to account for runout data (unfailed specimens over the duration of the experiment) was also included.
Scale-free models for the structure of business firm networks.
Kitsak, Maksim; Riccaboni, Massimo; Havlin, Shlomo; Pammolli, Fabio; Stanley, H Eugene
2010-03-01
We study firm collaborations in the life sciences and the information and communication technology sectors. We propose an approach to characterize industrial leadership using k -shell decomposition, with top-ranking firms in terms of market value in higher k -shell layers. We find that the life sciences industry network consists of three distinct components: a "nucleus," which is a small well-connected subgraph, "tendrils," which are small subgraphs consisting of small degree nodes connected exclusively to the nucleus, and a "bulk body," which consists of the majority of nodes. Industrial leaders, i.e., the largest companies in terms of market value, are in the highest k -shells of both networks. The nucleus of the life sciences sector is very stable: once a firm enters the nucleus, it is likely to stay there for a long time. At the same time we do not observe the above three components in the information and communication technology sector. We also conduct a systematic study of these three components in random scale-free networks. Our results suggest that the sizes of the nucleus and the tendrils in scale-free networks decrease as the exponent of the power-law degree distribution lambda increases, and disappear for lambda>or=3 . We compare the k -shell structure of random scale-free model networks with two real-world business firm networks in the life sciences and in the information and communication technology sectors. We argue that the observed behavior of the k -shell structure in the two industries is consistent with the coexistence of both preferential and random agreements in the evolution of industrial networks.
Olsen, Siv Js; Fridlund, Bengt; Eide, Leslie Sp; Hufthammer, Karl O; Kuiper, Karel Kj; Nordrehaug, Jan E; Skaar, Elisabeth; Norekvål, Tone M
2017-01-01
In addition to favourable results regarding mortality and morbidity it is important to identify the impact transcatheter aortic valve implantation (TAVI) has on patients' quality of life. The aims were: (i) to describe clinical characteristics, self-reported health and quality of life in octogenarians before TAVI intervention; (ii) to determine changes in self-reported health and quality of life one month after TAVI; and (iii) to establish the clinical importance of the findings. A prospective cohort study was conducted on consecutively enrolled octogenarians with severe aortic stenosis undergoing TAVI ( N = 65). Self-reported health and quality of life were recorded at baseline and one month later using two global questions from the World Health Organization Quality of Life Instrument Abbreviated (WHOQOL-BREF), the generic Short Form Health 12 and the disease-specific Minnesota Living with Heart Failure Questionnaire. One month after TAVI, WHOQOL-BREF showed that self-reported health improved moderately ( p < 0.001), while quality of life improved slightly, but not statistically significantly ( p = 0.06). There were changes in all Short Form Health 12 domains, except social functioning and role emotional. The estimated changes were 3.6 to 5.8 with large confidence intervals. The Physical Component Summary increased statistically significantly from baseline to 30 days (30.6-34.7; p = 0.02), but the Mental Component Summary did not (46.9-50.0; p = 0.13). Despite being an advanced treatment performed in a high risk population, TAVI in octogenarians improves short-term self-reported global health and generic physical health and quality of life. These patient-reported outcomes have importance, particularly in this age group.
Acceptance and Commitment Therapy modules: Differential impact on treatment processes and outcomes.
Villatte, Jennifer L; Vilardaga, Roger; Villatte, Matthieu; Plumb Vilardaga, Jennifer C; Atkins, David C; Hayes, Steven C
2016-02-01
A modular, transdiagnostic approach to treatment design and implementation may increase the public health impact of evidence-based psychosocial interventions. Such an approach relies on algorithms for selecting and implementing treatment components intended to have a specific therapeutic effect, yet there is little evidence for how components function independent of their treatment packages when employed in clinical service settings. This study aimed to demonstrate the specificity of treatment effects for two components of Acceptance and Commitment Therapy (ACT), a promising candidate for modularization. A randomized, nonconcurrent, multiple-baseline across participants design was used to examine component effects on treatment processes and outcomes in 15 adults seeking mental health treatment. The ACT OPEN module targeted acceptance and cognitive defusion; the ACT ENGAGED module targeted values-based activation and persistence. According to Tau-U analyses, both modules produced significant improvements in psychiatric symptoms, quality of life, and targeted therapeutic processes. ACT ENGAGED demonstrated greater improvements in quality of life and values-based activation. ACT OPEN showed greater improvements in symptom severity, acceptance, and defusion. Both modules improved awareness and non-reactivity, which were mutually targeted, though using distinct intervention procedures. Both interventions demonstrated high treatment acceptability, completion, and patient satisfaction. Treatment effects were maintained at 3-month follow up. ACT components should be considered for inclusion in a modular approach to implementing evidence-based psychosocial interventions for adults. Copyright © 2015 Elsevier Ltd. All rights reserved.
Testing metals and alloys for use in oxygen systems
NASA Technical Reports Server (NTRS)
Stoltzfus, Joel M.
1986-01-01
When oxygen is present in high concentrations or large quantities, as in oxygen-based life-support systems, the likelihood of combustion and the probable intensity of a conflagration increase, together with the severity of the damage caused. Even stainless steel will burn vigorously when ignited in a 1000-psi oxygen environment. The hazards involved in the use of oxygen increase with system operation at the elevated temperatures typical of propulsion systems. Fires in oxygen systems are generally catastrophic, causing a threat to life in manned vehicles. When mechanical components of a mechanism generate friction heat in the presence of oxygen, many commonly used metal alloys ignite and burn. Attention is presently given to frictional heating, particle impact, and flame propagation tests conducted in oxygen environments.
Doubova, Svetlana V; Mino-León, Dolores; Pérez-Cuevas, Ricardo
2013-12-01
To assess the association between quality of care and health-related quality of life among type 2 diabetes patients. A cross-sectional study assessing the association between quality of care and quality of life using multiple linear regression analysis. Family medicine clinics (FMC) (n = 39) of the Mexican Institute of Social Security (IMSS) in Mexico City. Type 2 diabetes patients (n = 312), older than 19 years. Health-related quality of life was measured using the MOS Short-Form-12 (SF-12); quality of healthcare was measured as the percentage of recommended care received under each of four domains: early detection of diabetes complications, non-pharmacological treatment, pharmacological treatment and health outcomes. The average quality of life score was 41.4 points on the physical component and 47.9 points on the mental component. Assessment of the quality of care revealed deficiencies. The average percentages of recommended care received were 21.9 for health outcomes and 56.6 for early detection of diabetes complications and pharmacological treatment; for every 10 percent additional points on the pharmacological treatment component, quality of life improved by 0.4 points on the physical component (coefficient 0.04, 95% confidence intervals 0.01-0.07). There was a positive association between the quality of pharmacological care and the physical component of quality of life. The quality of healthcare for type 2 diabetes patients in FMC of the IMSS in Mexico City is not optimal.
Simulating advanced life support systems to test integrated control approaches
NASA Astrophysics Data System (ADS)
Kortenkamp, D.; Bell, S.
Simulations allow for testing of life support control approaches before hardware is designed and built. Simulations also allow for the safe exploration of alternative control strategies during life support operation. As such, they are an important component of any life support research program and testbed. This paper describes a specific advanced life support simulation being created at NASA Johnson Space Center. It is a discrete-event simulation that is dynamic and stochastic. It simulates all major components of an advanced life support system, including crew (with variable ages, weights and genders), biomass production (with scalable plantings of ten different crops), water recovery, air revitalization, food processing, solid waste recycling and energy production. Each component is modeled as a producer of certain resources and a consumer of certain resources. The control system must monitor (via sensors) and control (via actuators) the flow of resources throughout the system to provide life support functionality. The simulation is written in an object-oriented paradigm that makes it portable, extensible and reconfigurable.
Snus use during the life-course and risk of the metabolic syndrome and its components.
Byhamre, Marja Lisa; Gustafsson, Per E; Jansson, Jan-Håkan; Wennberg, Maria; Hammarström, Anne; Wennberg, Patrik
2017-12-01
We aimed to investigate the association between life-course exposure to snus and prevalence of the metabolic syndrome and its components in adulthood. Tobacco habits at baseline (age 16) and three follow-ups (ages 21, 30 and 43) were assessed among 880 participants in a population-based cohort in Northern Sweden. Presence of the metabolic syndrome at age 43 was ascertained using the International Diabetes Federation criteria. Odds ratios and CIs for risk of the metabolic syndrome and its components by snus use at 16, 21, 30 and 43 years were calculated using logistic regression. Cumulative snus use was defined as number of life periods (1-4) with current snus use. At age 43, 164 participants (18.6%) were current snus users. We found no association between exclusive snus use at the ages of 16, 21, 30 and 43 years and the metabolic syndrome at age 43 years. Snus use (among non-smokers) was associated with raised triglycerides and high blood pressure in crude analysis, but not in multivariable models. There was no association between cumulative snus use and risk of the metabolic syndrome. Cumulative snus use was associated with central obesity, raised triglycerides and impaired fasting glucose/diabetes mellitus type 2 in crude analyses, but not after adjustments. The health consequences of snus exposure from adolescence to mid-adulthood do not seem to include increased risk of the metabolic syndrome or its components. The cardio-metabolic risk of dual exposure to snus and cigarettes may warrant further attention.
Quality of Life After Cardiac Surgery Based on the Minimal Clinically Important Difference Concept.
Grand, Nathalie; Bouchet, Jean Baptiste; Zufferey, Paul; Beraud, Anne Marie; Awad, Sahar; Sandri, Fabricio; Campisi, Salvator; Fuzellier, Jean François; Molliex, Serge; Vola, Marco; Morel, Jerome
2018-03-23
Health-related quality of life (HRQOL) is an increasingly important issue in assessing the consequences of any surgical or medical intervention. Our study aimed to evaluate change in HRQOL 6 months after elective cardiac surgery and to identify specific predictors of poor HRQOL. In this prospective, single-center study, HRQOL was evaluated before and 6 months after surgery using the SF-36 questionnaire and its two components: the physical component summary (PCS) and the mental component summary (MCS). We distinguished patients with worsening of HRQOL according to the minimal clinically important difference. All consecutive adult patients undergoing cardiac surgery were included. 326 patients completed the preoperative and postoperative SF-36 questionnaires and 24 patients died before completing follow-up questionnaires. Based on the definition used, clinically significant deterioration of HRQOL was observed in 93 patients (26.6%) for PCS and 99 patients (28.2%) for MCS. Renal replacement for acute renal failure and mechanical ventilation for longer than 48 hours were independent risk factors for PCS and MCS worsening or death. Although our study showed overall improvement of QOL after cardiac surgery, over a quarter of the patients manifested deterioration of HRQOL at 6 months post-surgery. The findings from this study should help clinicians to inform patients about their likely postoperative functional status and quality of life. Copyright © 2018. Published by Elsevier Inc.
Kämpfer, Christoph; Seiler, Thomas-Benjamin; Beger, Anna-Lena; Jacobs, Georg; Löwer, Manuel; Moser, Franziska; Reimer, Julia; Trautz, Martin; Usadel, Björn; Wormit, Alexandra; Hollert, Henner
2017-01-01
Technical product harvesting (TEPHA) is a newly developing interdisciplinary approach in which bio-based production is investigated from a technical and ecological perspective. Society's demand for ecologically produced and sustainably operable goods is a key driver for the substitution of conventional materials like metals or plastics through bio-based alternatives. Technical product harvesting of near net shape grown components describes the use of suitable biomass for the production of technical products through influencing the natural shape of plants during their growth period. The use of natural materials may show positive effects on the amount of non-renewable resource consumption. This also increases the product recyclability at the end of its life cycle. Furthermore, through the near net shape growth of biomass, production steps can be reduced. As a consequence such approaches may save energy and the needed resources like crude oil, coal or gas. The derived near net shape grown components are not only considered beneficial from an environmental point of view. They can also have mechanical advantages through an intrinsic topology optimization in contrast to common natural materials, which are influenced in their shape after harvesting. In order to prove these benefits a comprehensive, interdisciplinary scientific strategy is needed. Here, both mechanical investigations and life cycle assessment as a method of environmental evaluation are used.
NASA Technical Reports Server (NTRS)
Dickson, B.; Cronkhite, J.; Bielefeld, S.; Killian, L.; Hayden, R.
1996-01-01
The objective of this study was to evaluate two techniques, Flight Condition Recognition (FCR) and Flight Load Synthesis (FIS), for usage monitoring and assess the potential benefits of extending the retirement intervals of life-limited components, thus reducing the operator's maintenance and replacement costs. Both techniques involve indirect determination of loads using measured flight parameters and subsequent fatigue analysis to calculate the life expended on the life-limited components. To assess the potential benefit of usage monitoring, the two usage techniques were compared to current methods of component retirement. In addition, comparisons were made with direct load measurements to assess the accuracy of the two techniques.
Life prediction of turbine components: On-going studies at the NASA Lewis Research Center
NASA Technical Reports Server (NTRS)
Spera, D. A.; Grisaffe, S. J.
1973-01-01
An overview is presented of the many studies at NASA-Lewis that form the turbine component life prediction program. This program has three phases: (1) development of life prediction methods for major failure modes through materials studies, (2) evaluation and improvement of these methods through a variety of burner rig studies on simulated components in research engines and advanced rigs. These three phases form a cooperative, interdisciplinary program. A bibliography of Lewis publications on fatigue, oxidation and coatings, and turbine engine alloys is included.
Thornton, Lisa M; Cheavens, Jennifer S; Heitzmann, Carolyn A; Dorfman, Caroline S; Wu, Salene M; Andersen, Barbara L
2014-12-01
Psychological interventions can attenuate distress and enhance coping for those with an initial diagnosis of cancer, but there are few intervention options for individuals with cancer recurrence. To address this gap, we developed and tested a novel treatment combining Mindfulness, Hope Therapy, and biobehavioral components. An uncontrolled, repeated measures design was used. Women (N = 32) with recurrent breast or gynecologic cancers were provided 20 treatment sessions in individual (n = 12) or group (n = 20) formats. On average, participants were middle aged (M = 58) and Caucasian (81%). Independent variables (i.e., hope and mindfulness) and psychological outcomes (i.e., depression, negative mood, worry, and symptoms of generalized anxiety disorder) were assessed pre-treatment and 2, 4, and 7 months later. Session-by-session therapy process (positive and negative affect, quality-of-life) and mechanism (use of intervention-specific skills) measures were also included. Distress, anxiety, and negative affect decreased, whereas positive affect and mental-health-related quality-of-life increased over the course of treatment, as demonstrated in mixed-effects models with the intent-to-treat sample. Both hope and mindfulness increased, and use of mindfulness skills was related to decreased anxiety. This treatment was feasible to deliver and was acceptable to patients. The trial serves as preliminary evidence for a multi-component intervention tailored to treat difficulties specific to recurrent cancer. The blending of the components was novel as well as theoretically and practically consistent. A gap in the literature is addressed, providing directions for testing interventions designed for patients coping with the continuing stressors and challenges of cancer recurrence.
Associations between birth weight and later body composition: evidence from the 4-component model.
Chomtho, Sirinuch; Wells, Jonathan C K; Williams, Jane E; Lucas, Alan; Fewtrell, Mary S
2008-10-01
Higher birth weight is associated with higher body mass index, traditionally interpreted as greater fatness or obesity, in later life. However, its relation with individual body-composition components and fat distribution remains unclear. We investigated associations between birth weight and later fat mass (FM), fat-free mass (FFM), and fat distribution. Body composition was assessed by the criterion 4-component model in 391 healthy children [mean (+/-SD) age, 11.7 +/- 4.2 y; 188 boys]. FM and FFM were adjusted for height (FMI = FM/height(2); FFMI = FFM/height(2)) and were expressed as SD scores (SDS). Findings were compared between the 4-component and simpler methods. Birth weight was positively associated with height in both sexes and was significantly positively associated with FFMI in boys, equivalent to a 0.18 SDS (95% CI: 0.04, 0.32) increase in FFMI per 1 SDS increase in birth weight. These associations were independent of puberty, physical activity, social class, ethnicity, and parental body mass index. Birth weight was not significantly related to percentage fat, FMI, or trunk FMI in either sex. Equivalent analyses using simpler methods showed a trend for a positive relation between birth weight and FMI in boys that became nonsignificant after adjusting for confounders. FFMI in later life in males is influenced by birth weight, a proxy for prenatal growth, but evidence for fetal programming of later FM or central adiposity is weak. Different body-composition techniques and data interpretation can influence results and should be considered when comparing studies.
PVD TBC experience on GE aircraft engines
NASA Technical Reports Server (NTRS)
Bartz, A.; Mariocchi, A.; Wortman, D. J.
1995-01-01
The higher performance levels of modern gas turbine engines present significant challenges in the reliability of materials in the turbine. The increased engine temperatures required to achieve the higher performance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of Thermal Barrier Coatings (TBC's) have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the Physical Vapor Deposition (PVD) process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 micrometer (0.005 in) PVD TBC have demonstrated component operating temperatures of 56-83 C (100-150 F) lower than uncoated components. Engine testing has also revealed the TBC is susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues the TBC erodes away in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area, however, a significant temperature reduction was realized over an airfoil without any TBC.
PVD TBC experience on GE aircraft engines
NASA Technical Reports Server (NTRS)
Maricocchi, Antonio; Bartz, Andi; Wortman, David
1995-01-01
The higher performance levels of modern gas turbine engines present significant challenges in the reliability of materials in the turbine. The increased engine temperatures required to achieve the higher performance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of thermal barrier coatings (TBC's) have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the physical vapor deposition (PVD) process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 micron (0.005 in) PVD TBC have demonstrated component operating temperatures of 56-83 C (100-150 F) lower than non-PVD TBC components. Engine testing has also revealed the TBC is susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues, the TBC erodes away in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area, however a significant temperature reduction was realized over an airfoil without TBC.
PVD TBC experience on GE aircraft engines
NASA Astrophysics Data System (ADS)
Maricocchi, A.; Bartz, A.; Wortman, D.
1997-06-01
The higher performance levels of modern gas turbine engines present significant challenges in the reli-ability of materials in the turbine. The increased engine temperatures required to achieve the higher per-formance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of thermal barrier coatings have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the physical vapor deposition process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 μm (0.005 in.) PVD TBC have demonstrated component operating tem-peratures of 56 to 83 °C (100 to 150 °F) lower than non-PVD TBC components. Engine testing has also revealed that TBCs are susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues, the TBC erodes in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area ; however, a significant temperature reduc-tion was realized over an airfoil without TBC.
Chaigne, Benjamin; Chizzolini, Carlo; Perneger, Thomas; Trendelenburg, Marten; Huynh-Do, Uyen; Dayer, Eric; Stoll, Thomas; von Kempis, Johannes; Ribi, Camillo
2017-03-28
To assess the impact of disease activity on health-related quality of life (HRQoL) in systemic lupus erythematosus (SLE). Cross-sectional study of patients included in the Swiss SLE Cohort Study between April 2007 and June 2014. HRQoL outcomes were based on the Medical Outcome Study Short Form 36 (SF-36). Disease activity was assessed by the SLE Disease Activity Index score with the Safety of Estrogens in SLE National Assessment modification (SELENA-SLEDAI) and by the physican's global assessment (PGA). Of the 252 patients included, 207 (82%) were women. Median [interquartile range (IQR)] age was 43 [32-57] years. SLE was active in 125 patients (49.6%). Median [IQR] mental component summary (MCS) in active vs inactive SLE was 40.0 [30.2-51.0] compared to 47.3 [39.2-52.8] (p < 0.01) and median [IQR] physical component summary (PCS) 43.7 [37.0-52.8] compared to 49.1 [38.4-55.6], respectively (p < 0.05). Increase in SELENA-SLEDAI or increase in PGA were negatively correlated with PCS and/or MCS. After adjusting for gender, age and disease duration, disease activity impacted on both PCS and MCS and all subscales except general health. Active lupus nephritis and musculoskeletal involvement were associated with physical limitations and emotional problems, increased bodily pain and poor social functioning. Low complement and/or presence of anti-dsDNA antibodies were associated with increased fatigue and reduced mental health. In patients with SLE, HRQoL is reduced in those with active disease. Impact of disease activity on HRQoL dimensions depends on SELENA-SLEDAI system components.
ERIC Educational Resources Information Center
Dees, Jonathan; Bussard, Caitlin; Momsen, Jennifer L.
2018-01-01
Phylogenetic trees have become increasingly important across the life sciences, and as a result, learning to interpret and reason from these diagrams is now an essential component of biology education. Unfortunately, students often struggle to understand phylogenetic trees. Style (i.e., diagonal or bracket) is one factor that has been observed to…
Adelante Ball: A Student-Developed Activity Designed to Increase Motivation and Participation
ERIC Educational Resources Information Center
Hansen, Ken
2010-01-01
Physical education is the type of discipline which can be taught in a variety of settings. While fitness was a principle component of daily instruction, various physical activities also served as the medium for teaching valuable life skills, such as respect, communication, trust, problem solving, and self-direction. In an effort to teach these…
USDA-ARS?s Scientific Manuscript database
Genetic solutions to postharvest crop loss can reduce cost and energy inputs while increasing food security, especially for banana (Musa acuminata), which is a significant component of worldwide food commerce. We have functionally characterized two banana E class (SEPALLATA3 [SEP3]) MADS box genes, ...
ERIC Educational Resources Information Center
Lieberman, Lauren J.; Wilson, Sandy
2005-01-01
Physical activity is an important component of a positive quality of life for all individuals. Lack of physical activity can lead to increased risk of cancer, heart disease, high blood pressure, diabetes, and obesity. For all children, physical activity that includes fitness (cardiovascular and muscular endurance, muscle strength, flexibility, and…
Case report combined hepatocellular and cholangiocarcinoma with sarcomatous transformation.
Boonsakan, Paisarn; Thangnapakorn, Orathai; Tapaneeyakorn, Jiemjit; Kositchaiwat, Sawit; Bunyaratvej, Sukhum
2007-03-01
Combined hepatocellular and cholangiocarcinoma with sarcomatous transformation was first recognized in Ramathibodi Hospital in 2005. This variant of carcinoma has been increasingly reported particularly from Asian countries. Dedifferentiation of the epithelial component to various sarcomatous components is likely the underlying mechanism. The causative factors of hepatocarcinogenesis in Thailand include chronic viral hepatitis B or C, exposures to aflatoxin B1 and nitrosamine(s) and occasionally some certain nodular hepatocellular lesions due to arterial hyperperfusion. It is suggested that the recent change of the Thai peoples' life style to an increased consumption of fast foods containing food preservatives especially nitrate or nitrite, the nitrosamine precursor may allow heavy exposure(s) to the chemical carcinogen(s) i.e. nitrosamine(s) leading to sarcomatous transformation of the carcinoma.
Effect of complex configurations on the description of properties of {sup 132}Sn beta decay
DOE Office of Scientific and Technical Information (OSTI.GOV)
Severyukhin, A. P., E-mail: sever@theor.jinr.ru; Sushenok, E. O.
2015-07-15
Gamow–Teller transitions in the beta decay of the {sup 132}Sn neutron-rich nucleus was described microscopically. The coupling of one- and two-phonon components of the wave functions was taken into account on the basis of Skyrme interactions featuring various contributions of the tensor component. A separable approximation of the particle—hole interaction made it possible tohole interaction perform calculations in a large configuration space. It was shown that an increase in the strength of the neutron—proton tensor interaction led to an increase in the energy of Gamow—Teller transitions. In addition, a decrease in the {sup 132}Sn half-life with respect to beta decaymore » was obtained.« less
Methodological issues in the quantitative assessment of quality of life.
Panagiotakos, Demosthenes B; Yfantopoulos, John N
2011-10-01
The term quality of life can be identified in Aristotle's classical writings of 330 BC. In his Nichomachian ethics he recognises the multiple relationships between happiness, well-being, "eudemonia" and quality of life. Historically the concept of quality of life has undergone various interpretations. It involves personal experience, perceptions and beliefs, attitudes concerning philosophical, cultural, spiritual, psychological, political, and financial aspects of everyday living. Quality of life has been extensively used both as an outcome and an explanatory factor in relation to human health, in various clinical trials, epidemiologic studies and health interview surveys. Because of the variations in the definition of quality of life, both in theory and in practice, there are also a wide range of procedures that are used to assess quality of life. In this paper several methodological issues regarding the tools used to evaluate quality of life is discussed. In summary, the use of components consisted of large number of classes, as well as the use of specific weights for each scale component, and the low-to-moderate inter-correlation level between the components, is evident from simulated and empirical studies.
Culture, personality, and subjective well-being: integrating process models of life satisfaction.
Schimmack, Ulrich; Radhakrishnan, Phanikiran; Oishi, Shigehiro; Dzokoto, Vivian; Ahadi, Stephan
2002-04-01
The authors examined the interplay of personality and cultural factors in the prediction of the affective (hedonic balance) and the cognitive (life satisfaction) components of subjective well-being (SWB). They predicted that the influence of personality on life satisfaction is mediated by hedonic balance and that the relation between hedonic balance and life satisfaction is moderated by culture. As a consequence, they predicted that the influence of personality on life satisfaction is also moderated by culture. Participants from 2 individualistic cultures (United States, Germany) and 3 collectivistic cultures (Japan, Mexico, Ghana) completed measures of Extraversion, Neuroticism, hedonic balance, and life satisfaction. As predicted, Extraversion and Neuroticism influenced hedonic balance to the same degree in all cultures, and hedonic balance was a stronger predictor of life satisfaction in individualistic than in collectivistic cultures. The influence of Extraversion and Neuroticism on life satisfaction was largely mediated by hedonic balance. The results suggest that the influence of personality on the emotional component of SWB is pancultural, whereas the influence of personality on the cognitive component of SWB is moderated by culture.
ω-6 Polyunsaturated fatty acids extend life span through the activation of autophagy
O'Rourke, Eyleen J.; Kuballa, Petric; Xavier, Ramnik; Ruvkun, Gary
2013-01-01
Adaptation to nutrient scarcity depends on the activation of metabolic programs to efficiently use internal reserves of energy. Activation of these programs in abundant food regimens can extend life span. However, the common molecular and metabolic changes that promote adaptation to nutritional stress and extend life span are mostly unknown. Here we present a response to fasting, enrichment of ω-6 polyunsaturated fatty acids (PUFAs), which promotes starvation resistance and extends Caenorhabditis elegans life span. Upon fasting, C. elegans induces the expression of a lipase, which in turn leads to an enrichment of ω-6 PUFAs. Supplementing C. elegans culture media with these ω-6 PUFAs increases their resistance to starvation and extends their life span in conditions of food abundance. Supplementation of C. elegans or human epithelial cells with these ω-6 PUFAs activates autophagy, a cell recycling mechanism that promotes starvation survival and slows aging. Inactivation of C. elegans autophagy components reverses the increase in life span conferred by supplementing the C. elegans diet with these fasting-enriched ω-6 PUFAs. We propose that the salubrious effects of dietary supplementation with ω-3/6 PUFAs (fish oils) that have emerged from epidemiological studies in humans may be due to a similar activation of autophagic programs. PMID:23392608
Rich, Paul M; Breshears, David D; White, Amanda B
2008-02-01
Ecosystem responses to key climate drivers are reflected in phenological dynamics such as the timing and degree of "green-up" that integrate responses over spatial scales from individual plants to ecosystems. This integration is clearest in ecosystems dominated by a single species or life form, such as seasonally dynamic grasslands or more temporally constant evergreen forests. Yet many ecosystems have substantial contribution of cover from both herbaceous and woody evergreen plants. Responses of mixed woody-herbaceous ecosystems to climate are of increasing concern due to their extensive nature, the potential for such systems to yield more complex responses than those dominated by a single life form, and projections that extreme climate and weather events will increase in frequency and intensity with global warming. We present responses of a mixed woody-herbaceous ecosystem type to an extreme event: regional-scale piñon pine mortality following an extended drought and the subsequent herbaceous green-up following the first wet period after the drought. This example highlights how reductions in greenness of the slower, more stable evergreen woody component can rapidly be offset by increases associated with resources made available to the relatively more responsive herbaceous component. We hypothesize that such two-phase phenological responses to extreme events are characteristic of many mixed woody-herbaceous ecosystems.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Researchers at the National Renewable Energy Laboratory's (NREL's) National Wind Technology Center (NWTC) are studying component controls, including new advanced actuators and sensors, for both conventional turbines as well as wind plants. This research will help develop innovative control strategies that reduce aerodynamic structural loads and improve performance. Structural loads can cause damage that increase maintenance costs and shorten the life of a turbine or wind plant.
Pagis, Michal; Tal, Orly; Cadge, Wendy
2017-04-01
Spiritual care is an increasingly important component of end of life care. As it emerges in Israel, it is intentionally built on a nonclerical model. Based on interviews with spiritual care providers in Israel, we find that they help patients and families talk about death and say goodbyes. They encourage the wrapping up of unfinished business, offer diverse cultural resources that can provide meaning, and use presence and touch to produce connection. As spiritual care emerges in Israel, providers are working with patients at the end of life in ways they see as quite distinct from rabbis. They offer broad frames of meaning to which patients from a range of religious traditions can connect.
Do, Nicoline C; Secher, Anna L; Cramon, Per; Ringholm, Lene; Watt, Torquil; Damm, Peter; Mathiesen, Elisabeth R
2017-02-01
The aim of this study was to explore changes in health-related quality of life, anxiety and depression symptoms during pregnancy in women with pregestational diabetes. An observational cohort study including 137 pregnant women with pregestational diabetes (110 with type 1 and 27 with type 2). To evaluate changes from early to late pregnancy, the internationally validated questionnaires 36-Item Short-Form Health Survey (SF-36) and Hospital Anxiety and Depression Scale (HADS) were completed at 8 and 33 gestational weeks. From early to late pregnancy, the SF-36 scales Physical Function, Role Physical, Bodily Pain and Physical Component Summary worsened (p < 0.0001 for all scales). Physical Component Summary score deteriorated from mean 52.3 (SD 6.5) to 40.0 (9.7) (p < 0.0001) and the deterioration was negatively associated with gestational weight gain in multiple linear regression (β = -0.34/kg, p = 0.03). The SF-36 scale Mental Health improved (p = 0.0009) and the Mental Component Summary score increased moderately from 47.6 (10.6) to 53.5 (8.6) (p < 0.0001). Greater improvement in Mental Component Summary score was seen with lower HbA1c in late pregnancy. The HADS anxiety score improved slightly from 5.0 (3.3) to 4.5 (3.4) (p = 0.04) whereas the HADS depression score remained unchanged. The prevalence of women with HADS anxiety or depression score ≥8 did not change. Physical quality of life deteriorated whereas mental quality of life improved slightly during pregnancy in women with pregestational diabetes. A minor reduction in anxiety and stable depression symptoms was observed. The results on mental health are reassuring, considering the great demands that pregnancy places on women with pregestational diabetes. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.
Sazlina, S G; Zaiton, A; Nor Afiah, M Z; Hayati, K S
2012-05-01
To determine the health related quality of life and its predictive factors among older people with non-communicable diseases attending primary care clinics. Cross-sectional study. Three public primary care clinics in a district in Selangor, Malaysia. Registered patients aged 55 years and above. A face-to-face interview was conducted using a validated questionnaire of Medical Outcome Study 36-item short form health survey (SF-36). The outcome measure was the health related quality of life (HRQoL) and other factors measured were socio demography, physical activity, social support (Duke-UNC Functional Social Support Questionnaire), and presence of non-communicable diseases. A total of 347 participants had non-communicable diseases which included hypertension (41.8%), type 2 diabetes (33.7%), asthma (4.8%), hyperlipidaemia (1.7%), coronary heart disease (1.2%), and osteoarthritis (0.2%). Age ≥ 65 years old (OR =2.23; 95%CI=1.42, 3.50), single (OR=1.75; 95%CI=1.06,2.90), presence of co-morbid condition (OR=1.66; 95%CI=1.06, 2.61), and poorer social support (OR=2.11; 95%CI=1.27, 3.51; p=0.002) were significant predictors of poorer physical component of HRQoL . In predicting lower mental health component of HRQoL, the significant predictors were women (OR=2.28; 95%CI=1.44, 3.62), Indian ethnicity (OR=1.86; 95%CI=1.08, 3.21) and poorer social support (OR=2.71; 95%CI=1.63, 4.51). No interactions existed between these predictors. Older people with non-communicable diseases were susceptible to lower health related quality of life. Increasing age, single, presence of co-morbid conditions, and poorer social support were predictors of lower physical health component of HRQoL. While the older women, Indian ethnicity and poorer social support reported lower mental health component of HRQoL.
Sasson, Isaac
2016-04-01
The educational gradient in life expectancy is well documented in the United States and in other low-mortality countries. Highly educated Americans, on average, live longer than their low-educated counterparts, who have recently seen declines in adult life expectancy. However, limiting the discussion on lifespan inequality to mean differences alone overlooks other dimensions of inequality and particularly disparities in lifespan variation. The latter represents a unique form of inequality, with higher variation translating into greater uncertainty in the time of death from an individual standpoint, and higher group heterogeneity from a population perspective. Using data from the National Vital Statistics System from 1990 to 2010, this is the first study to document trends in both life expectancy and S25--the standard deviation of age at death above 25--by educational attainment. Among low-educated whites, adult life expectancy declined by 3.1 years for women and by 0.6 years for men. At the same time, S25 increased by about 1.5 years among high school-educated whites of both genders, becoming an increasingly important component of total lifespan inequality. By contrast, college-educated whites benefited from rising life expectancy and record low variation in age at death, consistent with the shifting mortality scenario. Among blacks, adult life expectancy increased, and S25 plateaued or declined in nearly all educational attainment groups, although blacks generally lagged behind whites of the same gender on both measures. Documenting trends in lifespan variation can therefore improve our understanding of lifespan inequality and point to diverging trajectories in adult mortality across socioeconomic strata.
Factors Associated with Quality of Life among Hemodialysis Patients in Malaysia
Md. Yusop, Nor Baizura; Yoke Mun, Chan; Shariff, Zalilah Mohd; Beng Huat, Choo
2013-01-01
Although hemodialysis treatment has greatly increased the life expectancy of end stage renal disease patients, low quality of life among hemodialysis patients is frequently reported. This cross-sectional study aimed to determine the relationship between medical history, hemodialysis treatment and nutritional status with the mental and physical components of quality of life in hemodialysis patients. Respondents (n=90) were recruited from Hospital Kuala Lumpur and dialysis centres of the National Kidney Foundation of Malaysia. Data obtained included socio-demography, medical history, hemodialysis treatment and nutritional status. Mental and physical quality of life were measured using the Mental Composite Summary (MCS) and Physical Composite Summary (PCS) of the Short-Form Health Survey 36-items, a generic core of the Kidney Disease Quality of Life Short Form. Two summary measures and total SF-36 was scored as 0–100, with a higher score indicating better quality of life. Approximately 26 (30%) of respondents achieved the body mass index (24 kg/m2) and more than 80% (n=77) achieved serum albumin level (>35.0 mg/dL) recommended for hemodialysis patients. The majority of respondents did not meet the energy (n=72, 80%) and protein (n=68,75%) recommendations. The total score of SF-36 was 54.1±19.2, while the score for the mental and physical components were 45.0±8.6 and 39.6±8.6, respectively. Factors associated with a higher MCS score were absence of diabetes mellitus (p=0.000) and lower serum calcium (p=0.004), while higher blood flow (p=0.000), higher serum creatinine (p=0.000) and lower protein intake (p=0.006) were associated with a higher PCS score. To improve the overall quality of life of hemodialysis patients, a multidisciplinary intervention that includes medical, dietetic and psychosocial strategies that address factors associated with mental and physical quality of life are warranted to reduce further health complications and to improve quality of life. PMID:24358336
Gardner, Andrew W; Montgomery, Polly S
2008-06-01
To determine the effect of metabolic syndrome components on intermittent claudication, physical function, health-related quality of life, and peripheral circulation in patients with peripheral arterial disease (PAD), and to identify the metabolic syndrome components most predictive of each outcome measure. Patients limited by intermittent claudication with three (n = 48), four (n = 45), or five (n = 40) components of metabolic syndrome were studied. Patients were assessed on PAD-specific measures consisting of ankle-brachial index (ABI), initial claudication distance, absolute claudication distance, physical function measures, health-related quality of life, and calf blood flow and transcutaneous oxygen tension responses after 3 minutes of vascular occlusion. Initial claudication distance (mean +/- SD) progressively declined (P = .019) in those with three (203 +/- 167 m), four (124 +/- 77 m), and five (78 +/- 57 m) metabolic syndrome components, and absolute claudication distance progressively declined (P = .036) in these groups as well (414 +/- 224 m vs 323 +/- 153 m vs 249 +/- 152 m, respectively). Furthermore, compared with patients with only three components of metabolic syndrome, those with all five components had impaired values (P < .05) for peak oxygen uptake, ischemic window, 6-minute walk distance, self-perceived walking ability and health, daily physical activity, health-related quality of life on six of eight domains, calf hyperemia, and calf ischemia after vascular occlusion. Abdominal obesity was the predictor (P < .05) of exercise performance during the treadmill and 6-minute walk tests, as well as physical activity. Elevated fasting glucose was the predictor (P < .05) of peripheral vascular measures, self-perceived walking ability and health, and health-related quality of life. PAD patients with more metabolic syndrome components have worsened intermittent claudication, physical function, health-related quality of life, and peripheral circulation. Abdominal obesity and elevated fasting glucose are the metabolic syndrome components that are most predictive of these outcome measures. Aggressively treating these metabolic syndrome components may be particularly important in managing symptoms and long-term prognosis of PAD patients.
System life and reliability modeling for helicopter transmissions
NASA Technical Reports Server (NTRS)
Savage, M.; Brikmanis, C. K.
1986-01-01
A computer program which simulates life and reliability of helicopter transmissions is presented. The helicopter transmissions may be composed of spiral bevel gear units and planetary gear units - alone, in series or in parallel. The spiral bevel gear units may have either single or dual input pinions, which are identical. The planetary gear units may be stepped or unstepped and the number of planet gears carried by the planet arm may be varied. The reliability analysis used in the program is based on the Weibull distribution lives of the transmission components. The computer calculates the system lives and dynamic capacities of the transmission components and the transmission. The system life is defined as the life of the component or transmission at an output torque at which the probability of survival is 90 percent. The dynamic capacity of a component or transmission is defined as the output torque which can be applied for one million output shaft cycles for a probability of survival of 90 percent. A complete summary of the life and dynamic capacity results is produced by the program.
Ibrahim, Norhayati; Din, Normah Che; Ahmad, Mahadir; Ghazali, Shazli Ezzat; Said, Zaini; Shahar, Suzana; Ghazali, Ahmad Rohi; Razali, Rosdinom
2013-04-01
This study aimed to examine the role of social support and depression in predicting the quality of life among the elderly living in a rural Federal Land Development Authority (FELDA) community in Malaysia. A total of 162 elderly settlers of FELDA Sungai Tengi, aged 60 years and above, were selected by universal sampling method in this cross-sectional study. Three standardized instruments - the 12-item Short Form (SF-12), 15-item Geriatric Depression Scale (GDS-15) and Medical Outcome Study Social Support (MOS-Social Support) - were used to assess for quality of life, depression and social support. Quality of life of the elderly people in this community was high, especially in terms of physical components as compared to mental components. The mean scores for emotional role in the SF-12 was relatively the highest (90.74 ± 21.59) with social functioning being the lowest (30.35 ± 22.29). The results also showed that the mean value was higher for physical component summary (74.40) as compared to mental component summary (51.51). Approximately 23.5% suffered mild depression and only 2.5% had severe depression. This study showed that the elderly FELDA settlers have a high quality of life, mainly on the physical components of life and low rate of severe depression, a positive indicator of their psychological well-being. Social support in the form of emotional/informational support, and depression were significant factors related to their good quality of life. Copyright © 2013 Wiley Publishing Asia Pty Ltd.
On a Self-Tuning Impact Vibration Damper for Rotating Turbomachinery
NASA Technical Reports Server (NTRS)
Duffy, Kirsten P.; Bagley, Ronald L.; Mehmed, Oral; Choi, Ben (Technical Monitor)
2000-01-01
A self-tuning impact damper is investigated analytically and experimentally as a device to inhibit vibration and increase the fatigue life of rotating components in turbomachinery. High centrifugal loads in rotors can inactivate traditional impact dampers because of friction or misalignment of the damper in the g-field. Giving an impact damper characteristics of an acceleration tuned-mass damper enables the resulting device to maintain damper mass motion and effectiveness during high-g loading. Experimental results presented here verify that this self-tuning impact damper can be designed to follow an engine order line. damping rotor component resonance crossings.
A Novel Approach to Rotorcraft Damage Tolerance
NASA Technical Reports Server (NTRS)
Forth, Scott C.; Everett, Richard A.; Newman, John A.
2002-01-01
Damage-tolerance methodology is positioned to replace safe-life methodologies for designing rotorcraft structures. The argument for implementing a damage-tolerance method comes from the fundamental fact that rotorcraft structures typically fail by fatigue cracking. Therefore, if technology permits prediction of fatigue-crack growth in structures, a damage-tolerance method should deliver the most accurate prediction of component life. Implementing damage-tolerance (DT) into high-cycle-fatigue (HCF) components will require a shift from traditional DT methods that rely on detecting an initial flaw with nondestructive inspection (NDI) methods. The rapid accumulation of cycles in a HCF component will result in a design based on a traditional DT method that is either impractical because of frequent inspections, or because the design will be too heavy to operate efficiently. Furthermore, once a HCF component develops a detectable propagating crack, the remaining fatigue life is short, sometimes less than one flight hour, which does not leave sufficient time for inspection. Therefore, designing a HCF component will require basing the life analysis on an initial flaw that is undetectable with current NDI technology.
Effects of surface chemistry on hot corrosion life
NASA Technical Reports Server (NTRS)
Fryxell, R. E.; Gupta, B. K.
1984-01-01
Hot corrosion life prediction methodology based on a combination of laboratory test data and field service turbine components, which show evidence of hot corrosion, were examined. Components were evaluated by optical metallography, scanning electron microscopy (SEM), and electron micropulse (EMP) examination.
Advanced Ground Systems Maintenance Prognostics Project
NASA Technical Reports Server (NTRS)
Harp, Janicce Leshay
2014-01-01
The project implements prognostics capabilities to predict when a component, system or subsystem will no longer meet desired functional or performance criteria, called the "end of life." The capability also provides an assessment of the "remaining useful life" of a hardware component.
Sun, Yaning; Yolitz, Jason; Alberico, Thomas; Sun, Xiaoping; Zou, Sige
2014-02-01
Many nutraceuticals and pharmaceuticals have been shown to promote healthspan and lifespan. However, the mechanisms underlying the beneficial effects of prolongevity interventions and the time points at which interventions should be implemented to achieve beneficial effects are not well characterized. We have previously shown that a cranberry-containing nutraceutical can promote lifespan in worms and flies and delay age-related functional decline of pancreatic cells in rats. Here we investigated the mechanism underlying lifespan extension induced by cranberry and the effects of short-term or life stage-specific interventions with cranberry on lifespan in Drosophila. We found that lifespan extension induced by cranberry was associated with reduced phosphorylation of ERK, a component of oxidative stress response MAPK signaling, and slightly increased phosphorylation of AKT, a component of insulin-like signaling. Lifespan extension was also associated with a reduced level of 4-hydroxynonenal protein adducts, a biomarker of lipid oxidation. Moreover, lifespan extension induced by cranberry was partially suppressed by knockdown of SOD2, a major mitochondrial superoxide scavenger. Furthermore, cranberry supplementation was administered in three life stages of adult flies, health span (3-30 days), transition span (31-60 days) and senescence span (61 days to the end when all flies died). Cranberry supplementation during any of these life stages extended the remaining lifespan relative to the non-supplemented and life stage-matched controls. These findings suggest that cranberry supplementation is sufficient to promote longevity when implemented during any life stage, likely through reducing oxidative damage. Published by Elsevier Inc.
Dzul, Maria C.; Dixon, Philip M.; Quist, Michael C.; Dinsomore, Stephen J.; Bower, Michael R.; Wilson, Kevin P.; Gaines, D. Bailey
2013-01-01
We used variance components to assess allocation of sampling effort in a hierarchically nested sampling design for ongoing monitoring of early life history stages of the federally endangered Devils Hole pupfish (DHP) (Cyprinodon diabolis). Sampling design for larval DHP included surveys (5 days each spring 2007–2009), events, and plots. Each survey was comprised of three counting events, where DHP larvae on nine plots were counted plot by plot. Statistical analysis of larval abundance included three components: (1) evaluation of power from various sample size combinations, (2) comparison of power in fixed and random plot designs, and (3) assessment of yearly differences in the power of the survey. Results indicated that increasing the sample size at the lowest level of sampling represented the most realistic option to increase the survey's power, fixed plot designs had greater power than random plot designs, and the power of the larval survey varied by year. This study provides an example of how monitoring efforts may benefit from coupling variance components estimation with power analysis to assess sampling design.
Religiousness and health-related quality of life of older adults
Abdala, Gina Andrade; Kimura, Miako; Duarte, Yeda Aparecida de Oliveira; Lebrão, Maria Lúcia; dos Santos, Bernardo
2015-01-01
OBJECTIVE To examine whether religiousness mediates the relationship between sociodemographic factors, multimorbidity and health-related quality of life of older adults. METHODS This population-based cross-sectional study is part of the Survey on Health, Well-Being, and Aging (SABE). The sample was composed by 911 older adults from Sao Paulo, SP, Southeastern Brazil. Structural equation modeling was performed to assess the mediator effect of religiousness on the relationship between selected variables and health-related quality of life of older adults, with models for men and women. The independent variables were: age, education, family functioning and multimorbidity. The outcome variable was health-related quality of life of older adults, measured by SF-12 (physical and mental components). The mediator variables were organizational, non-organizational and intrinsic religiousness. Cronbach’s alpha values were: physical component = 0.85; mental component = 0.80; intrinsic religiousness = 0.89 and family APGAR (Adaptability, Partnership, Growth, Affection, and Resolve) = 0.91. RESULTS Higher levels of organizational and intrinsic religiousness were associated with better physical and mental components. Higher education, better family functioning and fewer diseases contributed directly to improved performance in physical and mental components, regardless of religiousness. For women, organizational religiousness mediated the relationship between age and physical (β = 2.401, p < 0.01) and mental (β = 1.663, p < 0.01) components. For men, intrinsic religiousness mediated the relationship between education and mental component (β = 7.158, p < 0.01). CONCLUSIONS Organizational and intrinsic religiousness had a beneficial effect on the relationship between age, education and health-related quality of life of these older adults. PMID:26274870
[Religiousness and health-related quality of life of older adults].
Abdala, Gina Andrade; Kimura, Miako; Duarte, Yeda Aparecida de Oliveira; Lebrão, Maria Lúcia; dos Santos, Bernardo
2015-01-01
To examine whether religiousness mediates the relationship between sociodemographic factors, multimorbidity and health-related quality of life of older adults. This population-based cross-sectional study is part of the Survey on Health, Well-Being, and Aging (SABE). The sample was composed by 911 older adults from Sao Paulo, SP, Southeastern Brazil. Structural equation modeling was performed to assess the mediator effect of religiousness on the relationship between selected variables and health-related quality of life of older adults, with models for men and women. The independent variables were: age, education, family functioning and multimorbidity. The outcome variable was health-related quality of life of older adults, measured by SF-12 (physical and mental components). The mediator variables were organizational, non-organizational and intrinsic religiousness. Cronbach's alpha values were: physical component = 0.85; mental component = 0.80; intrinsic religiousness = 0.89 and family APGAR (Adaptability, Partnership, Growth, Affection, and Resolve) = 0.91. Higher levels of organizational and intrinsic religiousness were associated with better physical and mental components. Higher education, better family functioning and fewer diseases contributed directly to improved performance in physical and mental components, regardless of religiousness. For women, organizational religiousness mediated the relationship between age and physical (β = 2.401, p < 0.01) and mental (β = 1.663, p < 0.01) components. For men, intrinsic religiousness mediated the relationship between education and mental component (β = 7.158, p < 0.01). Organizational and intrinsic religiousness had a beneficial effect on the relationship between age, education and health-related quality of life of these older adults.
Laird, Barry J A; Fallon, Marie; Hjermstad, Marianne J; Tuck, Sharon; Kaasa, Stein; Klepstad, Pål; McMillan, Donald C
2016-08-10
Quality of life is a key component of cancer care; however, the factors that determine quality of life are not well understood. The aim of this study was to examine the relationship between quality of life parameters, performance status (PS), and the systemic inflammatory response in patients with advanced cancer. An international biobank of patients with advanced cancer was analyzed. Quality of life was assessed at a single time point by using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C-30 (EORTC QLQ-C30). PS was assessed by using the Eastern Cooperative Oncology Group (ECOG) classification. Systemic inflammation was assessed by using the modified Glasgow Prognostic Score (mGPS), which combines C-reactive protein and albumin. The relationship between quality of life parameters, ECOG PS, and the mGPS was examined. Data were available for 2,520 patients, and the most common cancers were GI (585 patients [22.2%]) and pulmonary (443 patients [17.6%]). The median survival was 4.25 months (interquartile range, 1.36 to 12.9 months). Increasing mGPS (systemic inflammation) and deteriorating PS were associated with deterioration in quality-of-life parameters (P < .001). Increasing systemic inflammation was associated with deterioration in quality-of-life parameters independent of PS. Systemic inflammation was associated with quality-of-life parameters independent of PS in patients with advanced cancer. Further investigation of these relationships in longitudinal studies and investigations of possible effects of attenuating systemic inflammation are now warranted. © 2016 by American Society of Clinical Oncology.
Life Predicted in a Probabilistic Design Space for Brittle Materials With Transient Loads
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Palfi, Tamas; Reh, Stefan
2005-01-01
Analytical techniques have progressively become more sophisticated, and now we can consider the probabilistic nature of the entire space of random input variables on the lifetime reliability of brittle structures. This was demonstrated with NASA s CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code combined with the commercially available ANSYS/Probabilistic Design System (ANSYS/PDS), a probabilistic analysis tool that is an integral part of the ANSYS finite-element analysis program. ANSYS/PDS allows probabilistic loads, component geometry, and material properties to be considered in the finite-element analysis. CARES/Life predicts the time dependent probability of failure of brittle material structures under generalized thermomechanical loading--such as that found in a turbine engine hot-section. Glenn researchers coupled ANSYS/PDS with CARES/Life to assess the effects of the stochastic variables of component geometry, loading, and material properties on the predicted life of the component for fully transient thermomechanical loading and cyclic loading.
Intelligent Life-Extending Controls for Aircraft Engines
NASA Technical Reports Server (NTRS)
Guo, Ten-Huei; Chen, Philip; Jaw, Link
2005-01-01
Aircraft engine controllers are designed and operated to provide desired performance and stability margins. The purpose of life-extending-control (LEC) is to study the relationship between control action and engine component life usage, and to design an intelligent control algorithm to provide proper trade-offs between performance and engine life usage. The benefit of this approach is that it is expected to maintain safety while minimizing the overall operating costs. With the advances of computer technology, engine operation models, and damage physics, it is necessary to reevaluate the control strategy fro overall operating cost consideration. This paper uses the thermo-mechanical fatigue (TMF) of a critical component to demonstrate how an intelligent engine control algorithm can drastically reduce the engine life usage with minimum sacrifice in performance. A Monte Carlo simulation is also performed to evaluate the likely engine damage accumulation under various operating conditions. The simulation results show that an optimized acceleration schedule can provide a significant life saving in selected engine components.
ERIC Educational Resources Information Center
Busseri, Michael; Sadava, Stanley; DeCourville, Nancy
2007-01-01
The primary components of subjective well-being (SWB) include life satisfaction (LS), positive affect (PA), and negative affect (NA). There is little consensus, however, concerning how these components form a model of SWB. In this paper, six longitudinal studies varying in demographic characteristics, length of time between assessment periods,…
Loubet, Philippe; Roux, Philippe; Bellon-Maurel, Véronique
2016-01-01
The emphasis on the sustainable urban water management has increased over the last decades. In this context decision makers need tools to measure and improve the environmental performance of urban water systems (UWS) and their related scenarios. In this paper, we propose a versatile model, named WaLA (Water system Life cycle Assessment), which reduces the complexity of the UWS while ensuring a good representation of water issues and fulfilling life cycle assessment (LCA) requirements. Indeed, LCAs require building UWS models, which can be tedious if several scenarios are to be compared. The WaLA model is based on a framework that uses a "generic component" representing alternately water technology units and water users, with their associated water flows, and the associated impacts due to water deprivation, emissions, operation and infrastructure. UWS scenarios can be built by inter-operating and connecting the technologies and users components in a modular and integrated way. The model calculates life cycle impacts at a monthly temporal resolution for a set of services provided to users, as defined by the scenario. It also provides the ratio of impacts to amount of services provided and useful information for UWS diagnosis or comparison of different scenarios. The model is implemented in a Matlab/Simulink interface thanks to object-oriented programming. The applicability of the model is demonstrated using a virtual case study based on available life cycle inventory data. Copyright © 2015 Elsevier Ltd. All rights reserved.
Jessica R. Haas; David E. Calkin; Matthew P. Thompson
2013-01-01
Ongoing human development into fire-prone areas contributes to increasing wildfire risk to human life. It is critically important, therefore, to have the ability to characterize wildfire risk to populated places, and to identify geographic areas with relatively high risk. A fundamental component of wildfire risk analysis is establishing the likelihood of wildfire...
Medium-term outcome in patients treated with total hip arthroplasty using a modular femoral stem.
Dagnino, Augusto; Grappiolo, Guido; Benazzo, Franco M; Learmonth, Ian D; Spotorno, Lorenzo; Portinaro, Nicola
2012-01-01
The clinical, radiographic and quality of life results of total hip arthroplasty using the MODULUS cementless modular femoral stem were reviewed. 48 patients who had a total hip arthroplasty using the MODULUS femoral stem were identified. Six had bilateral procedures, resulting in 60 hips with complete clinical and radiographic data. Mean age at implantation was 50 years (range 33 to 82). Mean follow-up was 59 months (range 50 months to 73). There were two early post-operative dislocations (within 2 days). One patient required further surgery to remove heterotopic bone. Mean Harris Hip Score increased from 37 points preoperatively (range, 7 to 66) to 89 points at final review (range, 65 to 100 points). Radiographic evaluation revealed that all implants were stable without evidence of osteolysis but three patients (5%) exhibited heterotopic ossification. Quality of life was evaluated with the SF36. The physical component increased from 29.2 points (range, 18.5 to 46.0) to 51.7 points (range 42.9 to 60.6) and the mental component from 375 points (range, 19.5 to 50.0) to 50 points (range 32,8 to 62.0).
Application of advanced coating techniques to rocket engine components
NASA Technical Reports Server (NTRS)
Verma, S. K.
1988-01-01
The materials problem in the space shuttle main engine (SSME) is reviewed. Potential coatings and the method of their application for improved life of SSME components are discussed. A number of advanced coatings for turbine blade components and disks are being developed and tested in a multispecimen thermal fatigue fluidized bed facility at IIT Research Institute. This facility is capable of producing severe strains of the degree present in blades and disk components of the SSME. The potential coating systems and current efforts at IITRI being taken for life extension of the SSME components are summarized.
Advanced Ground Systems Maintenance Prognostics Project
NASA Technical Reports Server (NTRS)
Perotti, Jose M.
2015-01-01
The project implements prognostics capabilities to predict when a component system or subsystem will no longer meet desired functional or performance criteria, called the end of life. The capability also provides an assessment of the remaining useful life of a hardware component. The project enables the delivery of system health advisories to ground system operators. This project will use modeling techniques and algorithms to assess components' health andpredict remaining life for such components. The prognostics capability being developed will beused:during the design phase and during pre/post operations to conduct planning and analysis ofsystem design, maintenance & logistics plans, and system/mission operations plansduring real-time operations to monitor changes to components' health and assess their impacton operations.This capability will be interfaced to Ground Operations' command and control system as a part ofthe AGSM project to help assure system availability and mission success. The initial modelingeffort for this capability will be developed for Liquid Oxygen ground loading applications.
High hunting pressure selects for earlier birth date: Wild boar as a case study
Gamelon, M.; Besnard, A.; Gaillard, J.-M.; Servanty, S.; Baubet, E.; Brandt, S.; Gimenez, O.
2011-01-01
Exploitation by humans affects the size and structure of populations. This has evolutionary and demographic consequences that have typically being studied independent of one another. We here applied a framework recently developed applying quantitative tools from population ecology and selection gradient analysis to quantify the selection on a quantitative trait-birth date-through its association with multiple fitness components. From the long-term monitoring (22 years) of a wild boar (Sus scrofa scrofa) population subject to markedly increasing hunting pressure, we found that birth dates have advanced by up to 12 days throughout the study period. During the period of low hunting pressure, there was no detectable selection. However, during the period of high hunting pressure, the selection gradient linking breeding probability in the first year of life to birth date was negative, supporting current life-history theory predicting selection for early births to reproduce within the first year of life with increasing adult mortality. ?? 2011 The Author(s). Evolution?? 2011 The Society for the Study of Evolution..
Goh, Shereen Giap Kah; Rusli, Bin Nordin; Khalid, Bin Abdul Kadir
2015-01-01
Diabetes mellitus (DM) is a complex and chronic disease with multiple complications leading to increased mortality and poor quality of life. Current studies have shown that lowering glycosylated haemoglobin (HbA1c) confers protection against microvascular complications. However, with more intensive glucose control to achieve HbA1c of less than 6.5%, there seems to be a significant increased risk of mortality and cardiovascular events. The current recommendation worldwide is for "tailoring" of DM management to risk and also quality of Life (QOL) which is a crucial component in determining the success or failure of DM management. In Asia, DM has become a health crisis but there is a lack of QOL assessment tool that is specific for Asians with wide spectrum of ethnicity, languages, religions and socio-economic differences. In this review, we discuss the evolution of DM management over the decade and the issues pertaining to QOL among people living with diabetes in Asia.
NASA Astrophysics Data System (ADS)
Beck, A. J.; Hodzic, A.; Soutis, C.; Wilson, C. W.
2011-12-01
Computer-based Life Cycle Analysis (LCA) models were carried out to compare lightweight composites with the traditional aluminium over their useful lifetime. The analysis included raw materials, production, useful life in operation and disposal at the end of the material's useful life. The carbon fibre epoxy resin composite could in some cases reduce the weight of a component by up to 40 % compared to aluminium. As the fuel consumption of an aircraft is strongly influenced by its total weight, the emissions can be significantly reduced by increasing the proportion of composites used in the aircraft structure. Higher emissions, compared to aluminium, produced during composites production meet their 'break even' point after certain number of time units when used in aircraft structures, and continue to save emissions over their long-term operation. The study highlighted the environmental benefits of using lightweight structures in aircraft design, and also showed that utilisation of composites in products without energy saving may lead to increased emissions in the environment.
Shelf life assessment of industrial durum wheat bread as a function of packaging system.
Licciardello, Fabio; Giannone, Virgilio; Del Nobile, Matteo Alessandro; Muratore, Giuseppe; Summo, Carmine; Giarnetti, Mariagrazia; Caponio, Francesco; Paradiso, Vito Michele; Pasqualone, Antonella
2017-06-01
This study compared the effect of different packaging systems on industrial durum wheat bread shelf-life, with regard to thermoformed packaging (TF) and flow-packaging (FP). Two TFs having different thickness and one FP were compared by assessing physico-chemical and sensorial properties and volatile compounds of sliced bread during 90days of storage. Texture, a w and bread moisture varied according to a first-order kinetic model, with FP samples ageing faster than TFs. Sensorial features such as consistency, stale odor, and sour odor, increased their intensity during storage. Furans decreased, whereas hexanal increased. The Principal Component Analysis of the whole dataset pointed out that the TF system at reduced thickness could be adopted up to 60days, without compromising the standard commercial life of industrial bread and allowing to save packaging material. The FP system would allow further saving, but it should be preferred when the expected product turnover is within 30days. Copyright © 2016 Elsevier Ltd. All rights reserved.
Scale-free models for the structure of business firm networks
NASA Astrophysics Data System (ADS)
Kitsak, Maksim; Riccaboni, Massimo; Havlin, Shlomo; Pammolli, Fabio; Stanley, H. Eugene
2010-03-01
We study firm collaborations in the life sciences and the information and communication technology sectors. We propose an approach to characterize industrial leadership using k -shell decomposition, with top-ranking firms in terms of market value in higher k -shell layers. We find that the life sciences industry network consists of three distinct components: a “nucleus,” which is a small well-connected subgraph, “tendrils,” which are small subgraphs consisting of small degree nodes connected exclusively to the nucleus, and a “bulk body,” which consists of the majority of nodes. Industrial leaders, i.e., the largest companies in terms of market value, are in the highest k -shells of both networks. The nucleus of the life sciences sector is very stable: once a firm enters the nucleus, it is likely to stay there for a long time. At the same time we do not observe the above three components in the information and communication technology sector. We also conduct a systematic study of these three components in random scale-free networks. Our results suggest that the sizes of the nucleus and the tendrils in scale-free networks decrease as the exponent of the power-law degree distribution λ increases, and disappear for λ≥3 . We compare the k -shell structure of random scale-free model networks with two real-world business firm networks in the life sciences and in the information and communication technology sectors. We argue that the observed behavior of the k -shell structure in the two industries is consistent with the coexistence of both preferential and random agreements in the evolution of industrial networks.
CARES/LIFE Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Powers, Lynn M.; Janosik, Lesley A.; Gyekenyesi, John P.
2003-01-01
This manual describes the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction (CARES/LIFE) computer program. The program calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/or proof test loading. CARES/LIFE is an extension of the CARES (Ceramic Analysis and Reliability Evaluation of Structures) computer program. The program uses results from MSC/NASTRAN, ABAQUS, and ANSYS finite element analysis programs to evaluate component reliability due to inherent surface and/or volume type flaws. CARES/LIFE accounts for the phenomenon of subcritical crack growth (SCG) by utilizing the power law, Paris law, or Walker law. The two-parameter Weibull cumulative distribution function is used to characterize the variation in component strength. The effects of multiaxial stresses are modeled by using either the principle of independent action (PIA), the Weibull normal stress averaging method (NSA), or the Batdorf theory. Inert strength and fatigue parameters are estimated from rupture strength data of naturally flawed specimens loaded in static, dynamic, or cyclic fatigue. The probabilistic time-dependent theories used in CARES/LIFE, along with the input and output for CARES/LIFE, are described. Example problems to demonstrate various features of the program are also included.
Life review based on remembering specific positive events in active aging.
Latorre, José M; Serrano, Juan P; Ricarte, Jorge; Bonete, Beatriz; Ros, Laura; Sitges, Esther
2015-02-01
The aim of this study is to evaluate the effectiveness of life review (LR) based on specific positive events in non-depressed older adults taking part in an active aging program. Fifty-five older adults were randomly assigned to an experimental group or an active control (AC) group. A six-session individual training of LR based on specific positive events was carried out with the experimental group. The AC group undertook a "media workshop" of six sessions focused on learning journalistic techniques. Pre-test and post-test measures included life satisfaction, depressive symptoms, experiencing the environment as rewarding, and autobiographical memory (AM) scales. LR intervention decreased depressive symptomatology, improved life satisfaction, and increased specific memories. The findings suggest that practice in AM for specific events is an effective component of LR that could be a useful tool in enhancing emotional well-being in active aging programs, thus reducing depressive symptoms. © The Author(s) 2014.
Health programmes for school employees: improving quality of life, health and productivity.
Kolbe, Lloyd J; Tirozzi, Gerald N; Marx, Eva; Bobbitt-Cooke, Mary; Riedel, Sara; Jones, Jack; Schmoyer, Michael
2005-01-01
School health programmes in the 21st century could include eight components: 1) health services; 2) health education; 3) healthy physical and psychosocial environments; 4) psychological, counselling, and social services; 5) physical education and other physical activities; 6) healthy food services; and 7) integrated efforts of schools, families, and communities to improve the health of school students and employees. The eighth component of modern school health programmes, health programmes for school employees, is the focus of this article. Health programmes for school employees could be designed to increase the recruitment, retention, and productivity of school employees by partially focusing each of the preceding seven components of the school health programme on improving the health and quality of life of school employees as well as students. Thus, efforts to improve the quality of life, health, and productivity of school employees may be distinct from, but integrated with, efforts to improve the quality of life, health, and education of students. School employee health programmes can improve employee: 1) recruitment; 2) morale; 3) retention; and 4) productivity. They can reduce employee: 5) risk behaviours (e.g., physical inactivity); 6) risk factors (e.g., stress, obesity, high blood pressure); (7) illnesses; 8) work-related injuries; 9) absentee days; 10) worker compensation and disability claims; and 11) health care and health insurance costs. Further, if we hope to improve our schools' performance and raise student achievement levels, developing effective school employee health programmes can increase the likelihood that employees will: 12) serve as healthy role models for students; 13) implement effective school health programmes for students; and 14) present a positive image of the school to the community. If we are to improve the quality of life, health, and productivity of school employees in the 21st century: school administrators, employees, and policymakers must be informed about the need and the means to do so; school employee health programmes must become part of the culture of education and the expectation of educators; and colleges that prepare school administrators and other school employees must provide the pre-service and in-service training, research, development, and leadership to make it happen. This article outlines ten actions that can be taken by school districts to build or improve school employee health programmes, and a list of websites that provides more detailed information about such programmes.
Cross-cultural aging in cognitive and affective components of subjective well-being.
Pethtel, Olivia; Chen, Yiwei
2010-09-01
The present study examined age and cultural differences in cognitive and affective components of subjective well-being. A sample of 188 American and Chinese young and older adults completed surveys measuring self-life satisfaction, perceived family's life satisfaction, positive affect, and negative affect. Across cultures, older adults reported lower negative affect than did young adults. Americans reported higher self-life satisfaction, perceived family's life satisfaction, and positive affect than did Chinese. In addition, perceived family's life satisfaction was more related to self-life satisfaction for Chinese than for Americans. Findings are discussed in light of socioemotional selectivity theory and theories on culture and self-construal. (c) 2010 APA, all rights reserved.
NASA Technical Reports Server (NTRS)
Powers, L. M.; Jadaan, O. M.; Gyekenyesi, J. P.
1998-01-01
The desirable properties of ceramics at high temperatures have generated interest in their use for structural application such as in advanced turbine engine systems. Design lives for such systems can exceed 10,000 hours. The long life requirement necessitates subjecting the components to relatively low stresses. The combination of high temperatures and low stresses typically places failure for monolithic ceramics in the creep regime. The objective of this paper is to present a design methodology for predicting the lifetimes of structural components subjected to creep rupture conditions. This methodology utilizes commercially available finite element packages and takes into account the time-varying creep strain distributions (stress relaxation). The creep life, of a component is discretized into short time steps, during which the stress and strain distributions are assumed constant. The damage is calculated for each time step based on a modified Monkman-Grant creep rupture criterion. Failure is assumed to occur when the normalized accumulated damage at any point in the component is greater than or equal to unity. The corresponding time will be the creep rupture life for that component. Examples are chosen to demonstrate the Ceramics Analysis and Reliability Evaluation of Structures/CREEP (CARES/CREEP) integrated design program, which is written for the ANSYS finite element package. Depending on the component size and loading conditions, it was found that in real structures one of two competing failure modes (creep or slow crack growth) will dominate. Applications to benchmark problems and engine components are included.
NASA Technical Reports Server (NTRS)
Gyekenyesi, J. P.; Powers, L. M.; Jadaan, O. M.
1998-01-01
The desirable properties of ceramics at high temperatures have generated interest in their use for structural applications such as in advanced turbine systems. Design lives for such systems can exceed 10,000 hours. The long life requirement necessitates subjecting the components to relatively low stresses. The combination of high temperatures and low stresses typically places failure for monolithic ceramics in the creep regime. The objective of this paper is to present a design methodology for predicting the lifetimes of structural components subjected to creep rupture conditions. This methodology utilized commercially available finite element packages and takes into account the time-varying creep strain distributions (stress relaxation). The creep life of a component is discretized into short time steps, during which the stress and strain distributions are assumed constant. The damage is calculated for each time step based on a modified Monkman-Grant creep rupture criterion. Failure is assumed to occur when the normalized accumulated damage at any point in the component is greater than or equal to unity. The corresponding time will be the creep rupture life for that component. Examples are chosen to demonstrate the CARES/CREEP (Ceramics Analysis and Reliability Evaluation of Structures/CREEP) integrated design programs, which is written for the ANSYS finite element package. Depending on the component size and loading conditions, it was found that in real structures one of two competing failure modes (creep or slow crack growth) will dominate. Applications to benechmark problems and engine components are included.
A review of recent activities in the NASA CELSS program
NASA Technical Reports Server (NTRS)
Macelroy, R. D.; Tremor, J.; Smernoff, D. T.; Knott, W.; Prince, R. P.
1987-01-01
A CELSS (Controlled Ecological Life Support System) is a device that utilizes photosynthetic organisms and light energy to regenerate waste materials into oxygen and food for a crew in space. The results of theoretical and practical studies conducted by investigators within the CELSS program suggest that a bioregenerative life support system can be a useful and effective method of regenerating consumable materials for crew sustenance. Experimental data suggests that the operation of a CELSS in space will be practical if plants can be made to behave predictably in the space environment. Much of the work currently conducted within the CELSS program centers on the biological components of the CELSS system. The work is particularly directed at ways of achieving high efficiency and long term stability of all components of the system. Included are explorations of the conversion of nonedible cellulose to edible materials, nitrogen fixation by biological and chemical methods, and methods of waste processing. It is the intent of the presentation to provide a description of the extent to which a bioregenerative life support system can meet the constraints of the space environment, and to assess the degree to which system efficiency and stability can be increased during the next decade.
NASA Technical Reports Server (NTRS)
Zhu, Dongming
2014-01-01
Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is essential to the viability and reliability of the envisioned CMC engine component applications, ensuring integrated EBC-CMC system durability and designs are achievable for successful applications of the game-changing component technologies and lifing methodologies.This paper will emphasize recent NASA environmental barrier coating developments for SiCSiC turbine airfoil components, utilizing advanced coating compositions, state-of-the-art processing methods, and combined mechanical and environment testing and durability evaluations. The coating-CMC degradations in the engine fatigue-creep and operating environments are particularly complex; one of the important coating development aspects is to better understand engine environmental interactions and coating life debits, and we have particularly addressed the effect of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the durability of the environmental barrier coating systems, and how the temperature capability, stability and cyclic life of the candidate rare earth oxide and silicate coating systems will be impacted in the presence of the CMAS at high temperatures and under simulated heat flux conditions. Advanced environmental barrier coating systems, including HfO2-Si with rare earth dopant based bond coat systems, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.
Integrated Design Software Predicts the Creep Life of Monolithic Ceramic Components
NASA Technical Reports Server (NTRS)
1996-01-01
Significant improvements in propulsion and power generation for the next century will require revolutionary advances in high-temperature materials and structural design. Advanced ceramics are candidate materials for these elevated-temperature applications. As design protocols emerge for these material systems, designers must be aware of several innate features, including the degrading ability of ceramics to carry sustained load. Usually, time-dependent failure in ceramics occurs because of two different, delayedfailure mechanisms: slow crack growth and creep rupture. Slow crack growth initiates at a preexisting flaw and continues until a critical crack length is reached, causing catastrophic failure. Creep rupture, on the other hand, occurs because of bulk damage in the material: void nucleation and coalescence that eventually leads to macrocracks which then propagate to failure. Successful application of advanced ceramics depends on proper characterization of material behavior and the use of an appropriate design methodology. The life of a ceramic component can be predicted with the NASA Lewis Research Center's Ceramics Analysis and Reliability Evaluation of Structures (CARES) integrated design programs. CARES/CREEP determines the expected life of a component under creep conditions, and CARES/LIFE predicts the component life due to fast fracture and subcritical crack growth. The previously developed CARES/LIFE program has been used in numerous industrial and Government applications.
NASA Technical Reports Server (NTRS)
Vanfossen, G. J.
1983-01-01
A system which would allow a substantially increased output from a turboshaft engine for brief periods in emergency situations with little or no loss of turbine stress rupture life is proposed and studied analytically. The increased engine output is obtained by overtemperaturing the turbine; however, the temperature of the compressor bleed air used for hot section cooling is lowered by injecting and evaporating water. This decrease in cooling air temperature can offset the effect of increased gas temperature and increased shaft speed and thus keep turbine blade stress rupture life constant. The analysis utilized the NASA-Navy-Engine-Program or NNEP computer code to model the turboshaft engine in both design and off-design modes. This report is concerned with the effect of the proposed method of power augmentation on the engine cycle and turbine components. A simple cycle turboshaft engine with a 16:1 pressure ratio and a 1533 K (2760 R) turbine inlet temperature operating at sea level static conditions was studied to determine the possible power increase and the effect on turbine stress rupture life that could be expected using the proposed emergency cooling scheme. The analysis showed a 54 percent increse in output power can be achieved with no loss in gas generator turbine stress rupture life. A 231 K (415 F) rise in turbine inlet temperature is required for this level of augmentation. The required water flow rate was found to be .0109 kg water per kg of engine air flow.
Creep life management system for a turbine engine and method of operating the same
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tralshawala, Nilesh; Miller, Harold Edward; Badami, Vivek Venugopal
A creep life management system includes at least one sensor apparatus coupled to a first component. The at least one sensor apparatus is configured with a unique identifier. The creep life management system also includes at least one reader unit coupled to a second component. The at least one reader unit is configured to transmit an interrogation request signal to the at least one sensor apparatus and receive a measurement response signal transmitted from the at least one sensor apparatus. The creep life management system further includes at least one processor programmed to determine a real-time creep profile of themore » first component as a function of the measurement response signal transmitted from the at least one sensor apparatus.« less
A Critical Analysis of the Conventionally Employed Creep Lifing Methods
Abdallah, Zakaria; Gray, Veronica; Whittaker, Mark; Perkins, Karen
2014-01-01
The deformation of structural alloys presents problems for power plants and aerospace applications due to the demand for elevated temperatures for higher efficiencies and reductions in greenhouse gas emissions. The materials used in such applications experience harsh environments which may lead to deformation and failure of critical components. To avoid such catastrophic failures and also increase efficiency, future designs must utilise novel/improved alloy systems with enhanced temperature capability. In recognising this issue, a detailed understanding of creep is essential for the success of these designs by ensuring components do not experience excessive deformation which may ultimately lead to failure. To achieve this, a variety of parametric methods have been developed to quantify creep and creep fracture in high temperature applications. This study reviews a number of well-known traditionally employed creep lifing methods with some more recent approaches also included. The first section of this paper focuses on predicting the long-term creep rupture properties which is an area of interest for the power generation sector. The second section looks at pre-defined strains and the re-production of full creep curves based on available data which is pertinent to the aerospace industry where components are replaced before failure. PMID:28788623
Aerospace Systems Technical Research Operation Services (ASTROS) Industry Day (Briefing Charts)
2014-07-01
Integrated Motor Life Management AFM 315E – Green Propellant MCAT – Missile Component Advanced Tech EP – Electric Propulsion Distribution A...service life estimate •Distribution A: Approved for public release; unlimited distribution 23 MCAT (Motor Component Assessment Technology) What are
1991 NASA Life Support Systems Analysis workshop
NASA Technical Reports Server (NTRS)
Evanich, Peggy L.; Crabb, Thomas M.; Gartrell, Charles F.
1992-01-01
The 1991 Life Support Systems Analysis Workshop was sponsored by NASA Headquarters' Office of Aeronautics and Space Technology (OAST) to foster communication among NASA, industrial, and academic specialists, and to integrate their inputs and disseminate information to them. The overall objective of systems analysis within the Life Support Technology Program of OAST is to identify, guide the development of, and verify designs which will increase the performance of the life support systems on component, subsystem, and system levels for future human space missions. The specific goals of this workshop were to report on the status of systems analysis capabilities, to integrate the chemical processing industry technologies, and to integrate recommendations for future technology developments related to systems analysis for life support systems. The workshop included technical presentations, discussions, and interactive planning, with time allocated for discussion of both technology status and time-phased technology development recommendations. Key personnel from NASA, industry, and academia delivered inputs and presentations on the status and priorities of current and future systems analysis methods and requirements.
An Assessment of Integrated Health Management (IHM) Frameworks
DOE Office of Scientific and Technical Information (OSTI.GOV)
N. Lybeck; M. Tawfik; L. Bond
In order to meet the ever increasing demand for energy, the United States nuclear industry is turning to life extension of existing nuclear power plants (NPPs). Economically ensuring the safe, secure, and reliable operation of aging nuclear power plants presents many challenges. The 2009 Light Water Reactor Sustainability Workshop identified online monitoring of active and structural components as essential to the better understanding and management of the challenges posed by aging nuclear power plants. Additionally, there is increasing adoption of condition-based maintenance (CBM) for active components in NPPs. These techniques provide a foundation upon which a variety of advanced onlinemore » surveillance, diagnostic, and prognostic techniques can be deployed to continuously monitor and assess the health of NPP systems and components. The next step in the development of advanced online monitoring is to move beyond CBM to estimating the remaining useful life of active components using prognostic tools. Deployment of prognostic health management (PHM) on the scale of a NPP requires the use of an integrated health management (IHM) framework - a software product (or suite of products) used to manage the necessary elements needed for a complete implementation of online monitoring and prognostics. This paper provides a thoughtful look at the desirable functions and features of IHM architectures. A full PHM system involves several modules, including data acquisition, system modeling, fault detection, fault diagnostics, system prognostics, and advisory generation (operations and maintenance planning). The standards applicable to PHM applications are indentified and summarized. A list of evaluation criteria for PHM software products, developed to ensure scalability of the toolset to an environment with the complexity of a NPP, is presented. Fourteen commercially available PHM software products are identified and classified into four groups: research tools, PHM system development tools, deployable architectures, and peripheral tools.« less
Assessing inspection sensitivity as it relates to damage tolerance in composite rotor hubs
NASA Astrophysics Data System (ADS)
Roach, Dennis P.; Rackow, Kirk
2001-08-01
Increasing niche applications, growing international markets, and the emergence of advanced rotorcraft technology are expected to greatly increase the population of helicopters over the next decade. In terms of fuselage fatigue, helicopters show similar trends as fixed-wing aircraft. The highly unsteady loads experienced by rotating wings not only directly affect components in the dynamic systems but are also transferred to the fixed airframe structure. Expanded use of rotorcraft has focused attention on the use of new materials and the optimization of maintenance practices. The FAA's Airworthiness Assurance Center (AANC) at Sandia National Labs has joined with Bell Helicopter andother agencies in the rotorcraft industry to evaluate nondestructive inspection (NDI) capabilities in light of the damage tolerance of assorted rotorcraft structure components. Currently, the program's emphasis is on composite rotor hubs. The rotorcraft industry is constantly evaluating new types of lightweight composite materials that not only enhance the safety and reliability of rotor components but also improve performance and extended operating life as well. Composite rotor hubs have led to the use of bearingless rotor systems that are less complex and require less maintenance than their predecessors. The test facility described in this paper allows the structural stability and damage tolerance of composite hubs to be evaluated using realistic flight load spectrums of centrifugal force and bending loads. NDI was integrated into the life-cycle fatigue tests in order to evaluate flaw detection sensitivity simultaneously wiht residual strength and general rotor hub peformance. This paper will describe the evolving use of damage tolerance analysis (DTA) to direct and improve rotorcraft maintenance along with the related use of nondestructive inspections to manage helicopter safety. OVeralll, the data from this project will provide information to improve the producibility, inspectability, serviceability, and cost effectively of rotorcraft components.
Probabilistic/Fracture-Mechanics Model For Service Life
NASA Technical Reports Server (NTRS)
Watkins, T., Jr.; Annis, C. G., Jr.
1991-01-01
Computer program makes probabilistic estimates of lifetime of engine and components thereof. Developed to fill need for more accurate life-assessment technique that avoids errors in estimated lives and provides for statistical assessment of levels of risk created by engineering decisions in designing system. Implements mathematical model combining techniques of statistics, fatigue, fracture mechanics, nondestructive analysis, life-cycle cost analysis, and management of engine parts. Used to investigate effects of such engine-component life-controlling parameters as return-to-service intervals, stresses, capabilities for nondestructive evaluation, and qualities of materials.
NASA Astrophysics Data System (ADS)
Ocaña, J. L.; Porro, J. A.; Díaz, M.; Ruiz de Lara, L.; Correa, C.; Gil-Santos, A.; Peral, D.
2013-02-01
Laser shock processing (LSP) is being increasingly applied as an effective technology for the improvement of metallic materials mechanical and surface properties in different types of components as a means of enhancement of their corrosion and fatigue life behavior. As reported in previous contributions by the authors, a main effect resulting from the application of the LSP technique consists on the generation of relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Additional results accomplished by the authors in the line of practical development of the LSP technique at an experimental level (aiming its integral assessment from an interrelated theoretical and experimental point of view) are presented in this paper. Concretely, follow-on experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (especially Al and Ti alloys characteristic of high reliability components in the aerospace, nuclear and biomedical sectors) under different LSP irradiation conditions are presented along with a practical correlated analysis on the protective character of the residual stress profiles obtained under different irradiation strategies. Additional remarks on the improved character of the LSP technique over the traditional "shot peening" technique in what concerns depth of induced compressive residual stresses fields are also made through the paper.
NASA Technical Reports Server (NTRS)
Knight, Brent; Montgomery, Randall; Geist, David; Hunt, Ron; LaVerde, Bruce; Towner, Robert
2013-01-01
In a recent experimental study, small Particle Impact Dampers (PID) were bonded directly to the surface of printed circuit board (PCB) or printed wiring assemblies (PWA), reducing the random vibration response and increasing the fatigue life. This study provides data verifying practicality of this approach. The measured peak strain and acceleration response of the fundamental out of plane bending mode was significantly attenuated by adding a PID device. Attenuation of this mode is most relevant to the fatigue life of a PWA because the local relative displacements between the board and the supported components, which ultimately cause fatigue failures of the electrical leads of the board-mounted components are dominated by this mode. Applying PID damping at the board-level of assembly provides mitigation with a very small mass impact, especially as compared to isolation at an avionics box or shelf level of assembly. When compared with other mitigation techniques at the PWA level (board thickness, stiffeners, constrained layer damping), a compact PID device has the additional advantage of not needing to be an integral part of the design. A PID can simply be bonded to heritage or commercial off the shelf (COTS) hardware to facilitate its use in environments beyond which it was originally qualified. Finite element analysis and test results show that the beneficial effect is not localized and that the attenuation is not due to the simple addition of mass. No significant, detrimental reduction in frequency was observed. Side-by-side life testing of damped and un-damped boards at two different thicknesses (0.070" and 0.090") has shown that the addition of a PID was much more significant to the fatigue life than increasing the thickness. High speed video, accelerometer, and strain measurements have been collected to correlate with analytical results.
Energy Efficient Engine: High-pressure compressor test hardware detailed design report
NASA Technical Reports Server (NTRS)
Howe, David C.; Marchant, R. D.
1988-01-01
The objective of the NASA Energy Efficient Engine program is to identify and verify the technology required to achieve significant reductions in fuel consumption and operating cost for future commercial gas turbine engines. The design and analysis is documented of the high pressure compressor which was tested as part of the Pratt and Whitney effort under the Energy Efficient Engine program. This compressor was designed to produce a 14:1 pressure ratio in ten stages with an adiabatic efficiency of 88.2 percent in the flight propulsion system. The corresponding expected efficiency for the compressor component test rig is 86.5 percent. Other performance goals are a surge margin of 20 percent, a corrected flow rate of 35.2 kg/sec (77.5 lb/sec), and a life of 20,000 missions and 30,000 hours. Low loss, highly loaded airfoils are used to increase efficiency while reducing the parts count. Active clearance control and case trenches in abradable strips over the blade tips are included in the compressor component design to further increase the efficiency potential. The test rig incorporates variable geometry stator vanes in all stages to permit maximum flexibility in developing stage-to-stage matching. This provision precluded active clearance control on the rear case of the test rig. Both the component and rig designs meet or exceed design requirements with the exception of life goals, which will be achievable with planned advances in materials technology.
Han, Hye Joo; Schweickert, Richard; Xi, Zhuangzhuang; Viau-Quesnel, Charles
2016-04-01
For five individuals, a social network was constructed from a series of his or her dreams. Three important network measures were calculated for each network: transitivity, assortativity, and giant component proportion. These were monotonically related; over the five networks as transitivity increased, assortativity increased and giant component proportion decreased. The relations indicate that characters appear in dreams systematically. Systematicity likely arises from the dreamer's memory of people and their relations, which is from the dreamer's cognitive social network. But the dream social network is not a copy of the cognitive social network. Waking life social networks tend to have positive assortativity; that is, people tend to be connected to others with similar connectivity. Instead, in our sample of dream social networks assortativity is more often negative or near 0, as in online social networks. We show that if characters appear via a random walk, negative assortativity can result, particularly if the random walk is biased as suggested by remote associations. Copyright © 2015 Cognitive Science Society, Inc.
Quinic acid is a biologically active component of the Uncaria tomentosa extract C-Med 100.
Akesson, Christina; Lindgren, Hanna; Pero, Ronald W; Leanderson, Tomas; Ivars, Fredrik
2005-01-01
We have previously reported that the C-Med 100 extract of the plant Uncaria tomentosa induces prolonged lymphocyte half life and hence increased spleen cell number in mice receiving the extract in their drinking water. Further, the extract induces cell proliferation arrest and inhibits activation of the transcriptional regulator nuclear factor kappaB (NF-kappaB) in vitro. We now report that mice exposed to quinic acid (QA), a component of this extract, had significantly increased number of spleen cells, thus recapitulating the in vivo biological effect of C-Med 100 exposure. Commercially supplied QA (H(+) form) did not, however, inhibit cell proliferation in vitro, while the ammonia-treated QA (QAA) was a potent inhibitor. Both QA and QAA inhibited NF-kappaB activity in exposed cells at similar concentrations. Thus, our present data identify QA as a candidate component for both in vivo and in vitro biological effects of the C-Med 100 extract.
Bains, William; Xiao, Yao; Yu, Changyong
2015-01-01
The components of life must survive in a cell long enough to perform their function in that cell. Because the rate of attack by water increases with temperature, we can, in principle, predict a maximum temperature above which an active terrestrial metabolism cannot function by analysis of the decomposition rates of the components of life, and comparison of those rates with the metabolites’ minimum metabolic half-lives. The present study is a first step in this direction, providing an analytical framework and method, and analyzing the stability of 63 small molecule metabolites based on literature data. Assuming that attack by water follows a first order rate equation, we extracted decomposition rate constants from literature data and estimated their statistical reliability. The resulting rate equations were then used to give a measure of confidence in the half-life of the metabolite concerned at different temperatures. There is little reliable data on metabolite decomposition or hydrolysis rates in the literature, the data is mostly confined to a small number of classes of chemicals, and the data available are sometimes mutually contradictory because of varying reaction conditions. However, a preliminary analysis suggests that terrestrial biochemistry is limited to environments below ~150–180 °C. We comment briefly on why pressure is likely to have a small effect on this. PMID:25821932
Uchmanowicz, Izabella; Gobbens, Robbert J J
2015-01-01
Elderly people constitute over 80% of the population of patients with heart failure (HF). Frailty is a distinct biological syndrome that reflects decreased physiologic reserve and resistance to stressors. Moreover, frailty can serve as an independent predictor of visits to the emergency department, hospitalizations, and mortality. The purpose of this paper was to assess the relationship between frailty, anxiety and depression, and the health-related quality of life (HRQoL) of elderly patients with HF. The study included 100 patients (53 men and 47 women) with a diagnosis of HF. Frailty was measured using the Tilburg Frailty Indicator (TFI) scale. HRQoL was measured using the 36-Item Short Form Medical Outcomes Study Survey. To determine the prevalence of anxiety and depression, the Hospital Anxiety and Depression Scale was used. Frailty was found in 89% of the studied population. The study showed significant inverse correlations between the values of the physical component scale (PCS) domain results and TFI score, and a significant inverse correlation between the values of the mental component scale (MCS) domain and TFI score. When participants showed increased levels of frailty as measured by the TFI scale, there was also an increase in the levels of anxiety and depression. With increased anxiety and depression, there was deterioration in the quality of life of patients with HF. Frailty has a negative impact on the HRQoL results of elderly patients with HF. The assessment of frailty syndrome, and anxiety and depression should be taken into account when estimating risk and making therapeutic decisions for cardiovascular disease treatment and care.
Warthin tumor--morphological study of the stromal compartment.
Dăguci, Luminiţa; Simionescu, Cristiana; Stepan, A; Munteanu, Cristina; Dăguci, C; Bătăiosu, Marilena
2011-01-01
Warthin tumor is the second most common benign tumors of the parotid gland, after pleomorphic adenoma. Our study was performed on 21 cases with Warthin tumor diagnosed between 2005-2010, which were analyzed clinically, histologically and immunohistochemically, using anti-CD20 and anti-CD45RO antibodies. The analysis of age distribution within the investigated cases indicated that Warthin tumor incidence is increasing in the seventh decade of life, most patients being male (M/F 5/2). Histopathological, the analysis report of stroma÷parenchyma in 14 cases revealed a balanced distribution of the two components, in four cases, the epithelial component was predominant and in three cases, the stromal component was predominant. Immunohistochemical study for the two specific lymphocyte proliferation markers indicated positivity for both epithelial component and stroma. Cell layout of CD45RO and CD20cy at the level of lymphoid stroma had a similar pattern with normal or reactive lymph nodes.
Bang, Sunlee; Kim, Minho; Song, Sa-Kwang; Park, Soo-Jun
2008-01-01
As the elderly people living alone are enormously increasing recently, we need the system inferring activities of daily living (ADL) for maintaining healthy life and recognizing emergency. The system should be constructed with sensors, which are used to associate with people's living while remaining as non intrusive views as possible. To do this, the proposed system use a triaxial accelerometer sensor and environment sensors indicating contact with subject in home. Particularly, in order to robustly infer ADLs, we present component ADL, which is decided with conjunction of human motion together, not just only contacted object identification. It is an important component in inferring ADL. In special, component ADL decision firstly refines misclassified initial activities, which improves the accuracy of recognizing ADL. Preliminary experiments results for proposed system provides overall recognition rate of over 97% over 8 component ADLs, which can be effectively applicable to recognize the final ADLs.
Improved FCG-1 cell technology
NASA Astrophysics Data System (ADS)
Breault, R. D.; Congdon, J. V.; Coykendall, R. D.; Luoma, W. L.
1980-10-01
Fuel cell performance in the ribbed substrate cell configuration consistent with that projected for a commercial power plant is demonstrated. Tests were conducted on subscale cells and on two 20 cell stacks of 4.8 MW demonstrator size cell components. These tests evaluated cell stack materials, processes, components, and assembly configurations. The first task was to conduct a component development effort to introduce improvements in 3.7 square foot, ribbed substrate acid cell repeating parts which represented advances in performance, function, life, and lower cost for application in higher pressure and temperature power plants. Specific areas of change were the electrode substrate, catalyst, matrix, seals, separator plates, and coolers. Full sized ribbed substrate stack components incorporating more stable materials were evaluated at increased pressure (93 psia) and temperature (405 F) conditions. Two 20 cell stacks with a 3.7 square feet, ribbed substrate cell configuration were tested.
Diffusion Barriers to Increase the Oxidative Life of Overlay Coatings
NASA Technical Reports Server (NTRS)
Nesbitt, James A.; Lei, Jih-Fen
1999-01-01
Currently, most blades and vanes in the hottest section of aero gas turbine engines require some type of coating for oxidation protection. Newly developed single crystal superalloys have the mechanical potential to operate at increasingly higher component temperatures. However, at these elevated temperatures, coating/substrate interdiffusion can shorten the protective life of the coating. Diffusion barriers between overlay coatings and substrates are being examined to extend the protective life of the coating. A previously- developed finite-difference diffusion model has been modified to predict the oxidative life enhancement due to use of a diffusion barrier. The original diffusion model, designated COSIM, simulates Al diffusion in the coating to the growing oxide scale as well as Al diffusion into the substrate. The COSIM model incorporates an oxide growth and spalling model to provide the rate of Al consumption during cyclic oxidation. Coating failure is predicted when the Al concentration at the coating surface drops to a defined critical level. The modified COSIM model predicts the oxidative life of an overlay coating when a diffusion barrier is present eliminating diffusion of Al from the coating into the substrate. Both the original and the modified diffusion models have been used to predict the effectiveness of a diffusion barrier in extending the protective life of a NiCrAl overlay coating undergoing cyclic oxidation at 1100 C.
Szajek, Krzysztof; Wierszycki, Marcin
2016-01-01
Dental implant designing is a complex process which considers many limitations both biological and mechanical in nature. In earlier studies, a complete procedure for improvement of two-component dental implant was proposed. However, the optimization tasks carried out required assumption on representative load case, which raised doubts on optimality for the other load cases. This paper deals with verification of the optimal design in context of fatigue life and its main goal is to answer the question if the assumed load scenario (solely horizontal occlusal load) leads to the design which is also "safe" for oblique occlussal loads regardless the angle from an implant axis. The verification is carried out with series of finite element analyses for wide spectrum of physiologically justified loads. The design of experiment methodology with full factorial technique is utilized. All computations are done in Abaqus suite. The maximal Mises stress and normalized effective stress amplitude for various load cases are discussed and compared with the assumed "safe" limit (equivalent of fatigue life for 5e6 cycles). The obtained results proof that coronial-appical load component should be taken into consideration in the two component dental implant when fatigue life is optimized. However, its influence in the analyzed case is small and does not change the fact that the fatigue life improvement is observed for all components within whole range of analyzed loads.
Computational Fatigue Life Analysis of Carbon Fiber Laminate
NASA Astrophysics Data System (ADS)
Shastry, Shrimukhi G.; Chandrashekara, C. V., Dr.
2018-02-01
In the present scenario, many traditional materials are being replaced by composite materials for its light weight and high strength properties. Industries like automotive industry, aerospace industry etc., are some of the examples which uses composite materials for most of its components. Replacing of components which are subjected to static load or impact load are less challenging compared to components which are subjected to dynamic loading. Replacing the components made up of composite materials demands many stages of parametric study. One such parametric study is the fatigue analysis of composite material. This paper focuses on the fatigue life analysis of the composite material by using computational techniques. A composite plate is considered for the study which has a hole at the center. The analysis is carried on (0°/90°/90°/90°/90°)s laminate sequence and (45°/-45°)2s laminate sequence by using a computer script. The life cycles for both the lay-up sequence are compared with each other. It is observed that, for the same material and geometry of the component, cross ply laminates show better fatigue life than that of angled ply laminates.
Frost, Rachael; Kharicha, Kalpa; Jovicic, Ana; Liljas, Ann E M; Iliffe, Steve; Manthorpe, Jill; Gardner, Benjamin; Avgerinou, Christina; Goodman, Claire; Drennan, Vari M; Walters, Kate
2018-05-01
Mild frailty is common in later life, increasing the risk of hospitalisation, loss of independence and premature death. Targeted health promotion services may reduce adverse outcomes and increase quality of life; however, effective, well-developed theory-based interventions are lacking. We aimed to explore perceptions of health promotion behaviours undertaken by older people with mild frailty, barriers and facilitators to engagement, and identify potential components for new home-based health promotion services. We carried out 17 semi-structured qualitative interviews and six focus groups with 53 stakeholders, including 14 mildly frail older people, 12 family carers, 19 community health and social care professionals, and 8 homecare workers, in one urban and one semi-rural area of England. Transcripts were thematically analysed. Older people with mild frailty reported engaging in a variety of lifestyle behaviours to promote health and well-being. Key barriers or facilitators to engaging in these included transport, knowledge of local services, social support and acceptance of personal limitations. Older people, carers and professionals agreed that any new service should address social networks and mobility and tailor other content to each individual. Services should aim to increase motivation through focussing on independence and facilitate older people to continue carrying out behaviours that improve their well-being, as well as provide information, motivation, psychological support and practical support. Stakeholders agreed services should be delivered over a sustained period by trained non-specialist workers. New services including these components are likely to be acceptable to older people with mild frailty. © 2017 The Authors. Health and Social Care in the Community Published by John Wiley & Sons Ltd.
NASA Technical Reports Server (NTRS)
Nelson, Richard S.; Schoendorf, John F.
1986-01-01
As gas turbine technology continues to advance, the need for advanced life prediction methods for hot section components is becoming more and more evident. The complex local strain and temperature histories at critical locations must be accurately interpreted to account for the effects of various damage mechanisms (such as fatigue, creep, and oxidation) and their possible interactions. As part of the overall NASA HOST effort, this program is designed to investigate these fundamental damage processes, identify modeling strategies, and develop practical models which can be used to guide the early design and development of new engines and to increase the durability of existing engines.
NextGen Weather Processor Architecture Study
2010-03-09
achieved in a staged fashion , ideally with new components coming on-line in time to replace existing capabilities prior to their end-of-life dates... fashion , ideally with new components coming on-line in time to replace existing capabilities prior to their end-of-life dates. As part of NWP Segment...weather capabilities. These objectives are to be achieved in a staged fashion , ideally with new components coming on-line in time to replace existing
Advanced General Aviation Turbine Engine (GATE) concepts
NASA Technical Reports Server (NTRS)
Lays, E. J.; Murray, G. L.
1979-01-01
Concepts are discussed that project turbine engine cost savings through use of geometrically constrained components designed for low rotational speeds and low stress to permit manufacturing economies. Aerodynamic development of geometrically constrained components is recommended to maximize component efficiency. Conceptual engines, airplane applications, airplane performance, engine cost, and engine-related life cycle costs are presented. The powerplants proposed offer encouragement with respect to fuel efficiency and life cycle costs, and make possible remarkable airplane performance gains.
Impact of weight reduction on eating behaviors and quality of life: Influence of the obesity degree.
Riesco, Eléonor; Rossel, Nadia; Rusques, Coralie; Mirepoix, Marie; Drapeau, Vicky; Sanguignol, Frédéric; Mauriège, Pascale
2009-01-01
To examine the effects of a short-term weight reducing program on body composition, eating behaviors, and health-related quality of life (HRQL) of sedentary obese women characterized by different obesity degrees. 44 women with a BMI under 34.9 kg/m(2) and 39 women with a BMI above 35 kg/m(2) were studied. Fat mass and lean mass (electrical bioimpedance), eating behaviors (Three-Factor Eating Questionnaire), and HRQL (36-item short form, SF-36, questionnaire) were determined before and after weight loss. Disinhibition and hunger scores and their subscales decreased after weight loss in both groups (0.0001 < p < 0.04). Restriction increased after weight reduction in all women (p = 0.02). Among the five restriction subscales, flexible restriction increased in women with a BMI above 35 kg/m(2) (p = 0.008), whereas rigid restraint and avoidance of fattening foods increased in both groups (0.006 < p < 0.02). SF-36 Mental Component Score increased after weight loss in all women (p < 0.0001). A 3week weight reducing program changes selected eating behaviors and components of HRQL, irrespective of women's obesity degree. Data suggest that women with a BMI above 35 kg/m(2) could have a better weight control in the long term because of their higher flexible restriction after weight loss when compared to those whose BMI was under 34.9 kg/m(2). 2009 S. Karger AG, Basel.
Life Prediction for a CMC Component Using the NASALIFE Computer Code
NASA Technical Reports Server (NTRS)
Gyekenyesi, John Z.; Murthy, Pappu L. N.; Mital, Subodh K.
2005-01-01
The computer code, NASALIFE, was used to provide estimates for life of an SiC/SiC stator vane under varying thermomechanical loading conditions. The primary intention of this effort is to show how the computer code NASALIFE can be used to provide reasonable estimates of life for practical propulsion system components made of advanced ceramic matrix composites (CMC). Simple loading conditions provided readily observable and acceptable life predictions. Varying the loading conditions such that low cycle fatigue and creep were affected independently provided expected trends in the results for life due to varying loads and life due to creep. Analysis was based on idealized empirical data for the 9/99 Melt Infiltrated SiC fiber reinforced SiC.
An extended life and performance test of a low-power arcjet
NASA Technical Reports Server (NTRS)
Curran, Francis M.; Haag, Thomas W.
1988-01-01
An automated, cyclic life test was performed to demonstrate the reliability and endurance of a low power dc cycle arcjet thruster. Over 1000 hr and 500 on-off cycles were accumulated which would represent the requirements for about 15 years of on-orbit lifetime. A hydrogen/nitrogen propellant mixture was used to simulate decomposed hydrazine propellant and the power level was nominally 1.2 kW after the burn-in period. The arcjet operated in a very repeatable fashion from cycle to cycle. The steady state voltage increased by approximately 6 V over the first 300 hr, and then by only 3 V through the remainder of the test. Thrust measurements taken before, during, and after the test verified that the thruster performed in a consistent fashion throughout the tests at a specific impulse of 450 to 460 sec. Post-test component evaluation revealed limited erosion on both the anode and cathode. Other thruster components, including graphite seals, appeared undamaged.
Pacheco, Ernesto; Hoyos, Diana P; Watt, Willinton J; Lema, Lucía; Arango, Carlos M
2016-04-01
The objectives of the study were to describe the feasibility of an intervention in older women based on folk dances of the Colombian Caribbean region, and to analyze the effects of the intervention on physical fitness and health-related quality of life (HRQoL). A pilot study was conducted in a sample of 27 participants, 15 in the intervention group (IG) and 12 in the comparison group (CG). Caribbean Colombian dance rhythms were introduced as an intervention that lasted 12 weeks. Recruitment and retention was not optimal. Treatment fidelity components indicated that intervention was administered as intended. IG participants showed positive and statistically significant changes in some components of physical fitness. No significant changes were observed in HRQoL indicators for either group. In conclusion, the intervention was feasible, but recruitment and retention was challenging. Folk dances of the Colombian Caribbean region provoked significant results in physical fitness but not in HRQoL.
High-Heat-Flux Cyclic Durability of Thermal and Environmental Barrier Coatings
NASA Technical Reports Server (NTRS)
Zhu, Dongming; Ghosn, Louis L.; Miller, Robert A.
2007-01-01
Advanced ceramic thermal and environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect the engine components and further raise engine temperatures. For the supersonic vehicles currently envisioned in the NASA fundamental aeronautics program, advanced gas turbine engines will be used to provide high power density thrust during the extended supersonic flight of the aircraft, while meeting stringent low emission requirements. Advanced ceramic coating systems are critical to the performance, life and durability of the hot-section components of the engine systems. In this work, the laser and burner rig based high-heat-flux testing approaches were developed to investigate the coating cyclic response and failure mechanisms under simulated supersonic long-duration cruise mission. The accelerated coating cracking and delamination mechanism under the engine high-heat-flux, and extended supersonic cruise time conditions will be addressed. A coating life prediction framework may be realized by examining the crack initiation and propagation in conjunction with environmental degradation under high-heat-flux test conditions.
Impact of automatic calibration techniques on HMD life cycle costs and sustainable performance
NASA Astrophysics Data System (ADS)
Speck, Richard P.; Herz, Norman E., Jr.
2000-06-01
Automatic test and calibration has become a valuable feature in many consumer products--ranging from antilock braking systems to auto-tune TVs. This paper discusses HMDs (Helmet Mounted Displays) and how similar techniques can reduce life cycle costs and increase sustainable performance if they are integrated into a program early enough. Optical ATE (Automatic Test Equipment) is already zeroing distortion in the HMDs and thereby making binocular displays a practical reality. A suitcase sized, field portable optical ATE unit could re-zero these errors in the Ready Room to cancel the effects of aging, minor damage and component replacement. Planning on this would yield large savings through relaxed component specifications and reduced logistic costs. Yet, the sustained performance would far exceed that attained with fixed calibration strategies. Major tactical benefits can come from reducing display errors, particularly in information fusion modules and virtual `beyond visual range' operations. Some versions of the ATE described are in production and examples of high resolution optical test data will be discussed.
Sharon Hood; Barbara Bentz; Ken Gibson; Kevin Ryan; Gregg DeNitto
2007-01-01
Douglas-fir has life history traits that greatly enhance resistance to injury from fire, thereby increasing post-fire survival rates. Tools for predicting the probability of tree mortality following fire are important components of both pre-fire planning and post-fire management efforts. Using data from mixed-severity wildfire in Montana and Wyoming, Hood and Bentz (...
30 CFR 27.35 - Tests to determine life of critical components and subassemblies.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests to determine life of critical components and subassemblies. 27.35 Section 27.35 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test...
30 CFR 27.35 - Tests to determine life of critical components and subassemblies.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tests to determine life of critical components and subassemblies. 27.35 Section 27.35 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test...
Harding, Jessica; Freak-Poli, Rosanne Laura Armida; Backholer, Kathryn; Peeters, Anna
2013-05-01
Regular physical activity (PA) is associated with a reduced risk for chronic health conditions and improved health-related quality of life (HRQoL). Efforts to increase PA have included workplace health promotion. Currently, little is known about the effect of these programs on overall HRQoL. To evaluate whether participation in a pedometer-based PA program in the workplace was associated with changes in HRQoL. 487 voluntary employees enrolled in a health program completed the SF-12 Health Survey at baseline and 4 months. Change in Physical and Mental component summary scores (PCS; MCS) was assessed with multivariable regression analysis, adjusting for covariates. Participation in the program was associated with an increase of 1.5 MCS units (95% CI: 0.76, -2.09). Greater improvements in MCS were observed in those reporting an increased level of PA during the program [1.9 (CI: 0.78, 2.92) versus 0.9 (CI: -0.12, 2.03)] and a lower baseline MCS score [6.3 (CI: 4.80, 7.62) versus -1.5 (CI: -2.21, -0.80)]. No change in PCS was observed. Participation in this workplace PA program was associated with improvements in the mental component of HRQoL. We recommend the use of a broad perspective of health be used in both the implementation and evaluation of workplace PA programs.
Low thermal expansion seal ring support
Dewis, David W.; Glezer, Boris
2000-01-01
Today, the trend is to increase the temperature of operation of gas turbine engines. To cool the components with compressor discharge air, robs air which could otherwise be used for combustion and creates a less efficient gas turbine engine. The present low thermal expansion sealing ring support system reduces the quantity of cooling air required while maintaining life and longevity of the components. Additionally, the low thermal expansion sealing ring reduces the clearance "C","C'" demanded between the interface between the sealing surface and the tip of the plurality of turbine blades. The sealing ring is supported by a plurality of support members in a manner in which the sealing ring and the plurality of support members independently expand and contract relative to each other and to other gas turbine engine components.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1984-02-01
Trucks used for the delivery of coal have a relatively limited life because they must be specified for somewhat less than brute strength in order to achieve maximum payload within existing weight and length limitations. The major drive train components such as engine, transmission, and drive axles can last longer if rebuilt or remanufactured periodically. For that reason glider kits and other truck components ready for the installation of the drive chain are becoming increasingly popular. These kits have been available for many years, but were regarded only as a means of salvaging late model wrecks or burned trucks. Theirmore » recent acceptance as a means of periodic fleet updating is built around the low cost and immediate availability of remanufactured major components. The cost advantages in using these glider kits are discussed.« less
Filipe, O M S; Santos, Sónia A O; Domingues, M Rosário M; Vidal, M M; Silvestre, A J D; Neto, C P; Santos, E B H
2013-05-01
In this study, the relevance of photodegradation processes on the persistence of the fungicide thiram in waters was investigated. The photodegradation of thiram in Milli-Q water and in aqueous solutions of humic and fulvic acids, as well as the photodegradation in spiked river water were studied. Both pure thiram and one of its commercial formulations were used to prepare the solutions which were irradiated in a solar light simulator. In general, thiram photodegradation follows pseudo-first order kinetics. The half-life time of thiram 2mgL(-1) in Milli-Q water was 28min. However, the degradation rate of thiram was significantly increased (p=0.02) by the inert components of the thiram commercial formulation as well as by commercial humic acids and by fulvic acids isolated from river water (p<0.004). Thus, the half-life time of thiram decreased to 24min in the presence of the inert formulation components, while, in the presence of both humic and fulvic acids (10mgL(-1)) it decreased to 22min. Furthermore, thiram photodegradation in natural river water showed that there is a significant enhancement of the degradation rate constant of thiram relatively to Milli-Q water, corresponding to a decrease of about 38% in its half-life time. This increase of the degradation rate in river water seems to be higher than that observed in the presence of FA, suggesting that beyond organic matter, other natural river components can increase the thiram photodegradation rate. These results allow us to conclude that photodegradation by solar radiation can be an important degradation pathway of thiram in natural waters. HPLC-MS/MS allowed to identify, for the first time, three products of the photodegradation of thiram in aqueous solution. Three compounds were identified and their structure was corroborated by the MS(n) spectra fragmentation profile. Pathways for the formation of the products from thiram photodegradation are proposed and discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.
Tonetti, Maurizio S; Bottenberg, Peter; Conrads, Georg; Eickholz, Peter; Heasman, Peter; Huysmans, Marie-Charlotte; López, Rodrigo; Madianos, Phoebus; Müller, Frauke; Needleman, Ian; Nyvad, Bente; Preshaw, Philip M; Pretty, Iain; Renvert, Stefan; Schwendicke, Falk; Trombelli, Leonardo; van der Putten, Gert-Jan; Vanobbergen, Jacques; West, Nicola; Young, Alix; Paris, Sebastian
2017-03-01
Over the last two decades, progress in prevention and treatment of caries and periodontal diseases has been translated to better oral health and improved tooth retention in the adult population. The ageing population and the increasing expectations of good oral health-related quality of life in older age pose formidable challenges to clinical care and healthcare systems. The objective of this workshop was to critically review scientific evidence and develop specific recommendations to: (i) prevent tooth loss and retain oral function through prevention and treatment of caries and periodontal diseases later in life and (ii) increase awareness of the health benefits of oral health as an essential component of healthy ageing. Discussions were initiated by three systematic reviews covering aspects of epidemiology of caries and periodontal diseases in elders, the impact of senescence on caries and periodontal diseases and the effectiveness of interventions. Recommendations were developed based on evidence from the systematic reviews and expert opinion. Key messages included: (i) the ageing population, trends in risk factors and improved tooth retention point towards an expected increase in the total burden of disease posed by caries and periodontal diseases in the older population; (ii) specific surveillance is required to monitor changes in oral health in the older population; (iii) senescence impacts oral health including periodontitis and possibly caries susceptibility; (iv) evidence indicates that caries and periodontal diseases can be prevented and treated also in older adults; (v) oral health and functional tooth retention later in life provides benefits both in terms of oral and general quality of life and in terms of preventing physical decline and dependency by fostering a healthy diet; (vi) oral healthcare professionals and individuals should not base decisions impacting tooth retention on chronological age but on level of dependency, life expectancy, frailty, comfort and quality of life; and (vii) health policy should remove barriers to oral health care for vulnerable elders. Consensus was reached on specific actionable priorities for public health officials, oral healthcare professionals, educators and workforce planners, caregivers and relatives as well as for the public and ageing patients. Some priorities have major implications for policymakers as health systems need to adapt to the challenge by systemwide changes to enable (promote) tooth retention later in life and management of deteriorating oral health in increasingly dependent elders. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
[Personal satisfaction as a component of adult's quality of life in Medellin].
Cardona, Doris; Agudelo, Héctor B
2007-01-01
Determining personal satisfaction as the main component of the quality of life of men and women aged 20 to 64 in Medellin during 2005. This was a cross/sectional descriptive population study. Its primary source of information consisted of two samples (659 men and 683 women) representing 523,705 and 651,704 people respectively, according to population expansion factors, selected via probabilistic complex sampling, stratified by socioeconomic level, clustering, city blocks, houses and people. The quality of life for adults in Medellin is mainly represented by personal and economic aspects, their housing's physical environment and social security. The aspects analysed in this study were evaluated above 75%; personal abilities and capability produced the greatest satisfaction, whilst the economic situation and social security produced least satisfaction. There were no significant differences according to gender regarding personal satisfaction concerning various aspects of life. This study's contribution to knowledge lies in making evident the need to integrate each person's subjectivity, opinions and individual perception of his/her own life, since these are the main components in evaluating an individual's quality of life.
Weston, Sara J; Cox, Keith S; Condon, David M; Jackson, Joshua J
2016-10-01
The majority of life narrative research is performed using trained human coders. In contrast, automated linguistic analysis is oft employed in the study of verbal behaviors. These two methodological approaches are directly compared to determine the utility of automated linguistic analysis for the study of life narratives. In a study of in-person interviews (N = 158) and a second study of life stories collected online (N = 242), redemption scores are compared to the output of the Linguistic Inquiry and Word Count (Pennebaker, Francis & Booth, 2001). Additionally, patterns of language are found using exploratory principal components analysis. In both studies, redemption scores are modestly correlated with some LIWC categories and unassociated with the components. Patterns of language do not replicate across samples, indicating that the structure of language does not extend to a broader population. Redemption scores and linguistic components are independent predictors of life satisfaction up to 3 years later. These studies converge on the finding that human-coded redemption and automated linguistic analysis are complementary and nonredundant methods of analyzing life narratives, and considerations for the study of life narratives are discussed. © 2015 Wiley Periodicals, Inc.
Plant Species Loss Affects Life-History Traits of Aphids and Their Parasitoids
Petermann, Jana S.; Roscher, Christiane; Weigelt, Alexandra; Weisser, Wolfgang W.; Schmid, Bernhard
2010-01-01
The consequences of plant species loss are rarely assessed in a multi-trophic context and especially effects on life-history traits of organisms at higher trophic levels have remained largely unstudied. We used a grassland biodiversity experiment and measured the effects of two components of plant diversity, plant species richness and the presence of nitrogen-fixing legumes, on several life-history traits of naturally colonizing aphids and their primary and secondary parasitoids in the field. We found that, irrespective of aphid species identity, the proportion of winged aphid morphs decreased with increasing plant species richness, which was correlated with decreasing host plant biomass. Similarly, emergence proportions of parasitoids decreased with increasing plant species richness. Both, emergence proportions and proportions of female parasitoids were lower in plots with legumes, where host plants had increased nitrogen concentrations. This effect of legume presence could indicate that aphids were better defended against parasitoids in high-nitrogen environments. Body mass of emerged individuals of the two most abundant primary parasitoid species was, however, higher in plots with legumes, suggesting that once parasitoids could overcome aphid defenses, they could profit from larger or more nutritious hosts. Our study demonstrates that cascading effects of plant species loss on higher trophic levels such as aphids, parasitoids and secondary parasitoids begin with changed life-history traits of these insects. Thus, life-history traits of organisms at higher trophic levels may be useful indicators of bottom-up effects of plant diversity on the biodiversity of consumers. PMID:20700511
Sadler, E A; Braam, A W; Broese van Groenou, M I; Deeg, D J H; van der Geest, S
2006-09-01
Gerotranscendence defines a shift in meta-perspective from earlier materialistic and pragmatic concerns, toward more cosmic and transcendent ones in later life. Population-based studies that have empirically examined this concept using Tornstam's gerotranscendence scale, highlight cosmic transcendence as a core component, which includes a sense of belongingness with past and future generations. Such generative concerns may increase expectations regarding the quality of the bond with one's children in later life. This study examined whether the association between emotional support exchanged with children and feelings of loneliness later in life varied by the degree of cosmic transcendence of the older parent. Data from 1,845 older parents participating in a population-based study living in The Netherlands were analyzed from the 1995/1996 cycle of the Longitudinal Aging Study Amsterdam. Interviews included self-report measures of cosmic transcendence, loneliness, emotional support exchanged with children, health indicators, and marital status. Results indicated that a negative association between loneliness and level of emotional support exchanged with children was more pronounced among older parents with higher cosmic transcendence scores, in particular among the married. It is argued that cosmic transcendence reflects a sense of generativity and an increased emotional dependency on children in later life. Under favorable social conditions (supportive relationships with children and being married) cosmic transcendent views had a positive impact on social well-being in later life. When children no longer met emotional needs of older parents, cosmic transcendence increased feelings of loneliness.
Fabrication of ceramic substrate-reinforced and free forms
NASA Technical Reports Server (NTRS)
Quentmeyer, R. J.; Mcdonald, G.; Hendricks, R. C.
1985-01-01
Components fabricated of, or coated with, ceramics have lower parasitic cooling requirements. Techniques are discussed for fabricating thin-shell ceramic components and ceramic coatings for applications in rocket or jet engine environments. Thin ceramic shells with complex geometric forms involving convolutions and reentrant surfaces were fabricated by mandrel removal. Mandrel removal was combined with electroplating or plasma spraying and isostatic pressing to form a metal support for the ceramic. Rocket engine thrust chambers coated with 0.08 mm (3 mil) of ZrO2-8Y2O3 had no failures and a tenfold increase in engine life. Some measured mechanical properties of the plasma-sprayed ceramic are presented.
CMC Technology Advancements for Gas Turbine Engine Applications
NASA Technical Reports Server (NTRS)
Grady, Joseph E.
2013-01-01
CMC research at NASA Glenn is focused on aircraft propulsion applications. The objective is to enable reduced engine emissions and fuel consumption for more environmentally friendly aircraft. Engine system studies show that incorporation of ceramic composites into turbine engines will enable significant reductions in emissions and fuel burn due to increased engine efficiency resulting from reduced cooling requirements for hot section components. This presentation will describe recent progress and challenges in developing fiber and matrix constituents for 2700 F CMC turbine applications. In addition, ongoing research in the development of durable environmental barrier coatings, ceramic joining integration technologies and life prediction methods for CMC engine components will be reviewed.
PVD thermal barrier coating applications and process development for aircraft engines
NASA Astrophysics Data System (ADS)
Rigney, D. V.; Viguie, R.; Wortman, D. J.; Skelly, D. W.
1997-06-01
Thermal barrier coatings (TBCs) have been developed for application to aircraft engine components to improve service life in an increasingly hostile thermal environment. The choice of TBC type is related to the component, intended use, and economics. Selection of electron beam physical vapor deposition proc-essing for turbine blade is due in part to part size, surface finish requirements, thickness control needs, and hole closure issues. Process development of PVD TBCs has been carried out at several different sites, including GE Aircraft Engines (GEAE). The influence of processing variables on microstructure is dis-cussed, along with the GEAE development coater and initial experiences of pilot line operation.
The Application of Strain Range Partitioning Method to Torsional Creep-Fatigue Interaction
NASA Technical Reports Server (NTRS)
Zamrik, S. Y.
1975-01-01
The method of strain range partitioning was applied to a series of torsional fatigue tests conducted on tubular 304 stainless steel specimens at 1200 F. Creep strain was superimposed on cycling strain, and the resulting strain range was partitioned into four components; completely reversed plastic shear strain, plastic shear strain followed by creep strain, creep strain followed by plastic strain and completely reversed creep strain. Each strain component was related to the cyclic life of the material. The damaging effects of the individual strain components were expressed by a linear life fraction rule. The plastic shear strain component showed the least detrimental factor when compared to creep strain reversed by plastic strain. In the latter case, a reduction of torsional fatigue life in the order of magnitude of 1.5 was observed.
NASA Technical Reports Server (NTRS)
1997-01-01
Products made from advanced ceramics show great promise for revolutionizing aerospace and terrestrial propulsion and power generation. However, ceramic components are difficult to design because brittle materials in general have widely varying strength values. The CARES/Life software developed at the NASA Lewis Research Center eases this by providing a tool that uses probabilistic reliability analysis techniques to optimize the design and manufacture of brittle material components. CARES/Life is an integrated package that predicts the probability of a monolithic ceramic component's failure as a function of its time in service. It couples commercial finite element programs--which resolve a component's temperature and stress distribution - with reliability evaluation and fracture mechanics routines for modeling strength - limiting defects. These routines are based on calculations of the probabilistic nature of the brittle material's strength.
Kornmehl, Heather; Singh, Sanminder; Johnson, Mary Ann; Armstrong, April W
2017-09-01
Atopic dermatitis (AD) is a chronic disease requiring regular follow-up. To increase access to dermatological care, online management of AD is being studied. However, a critical knowledge gap exists in determining AD patients' quality of life in direct-to-patient online models. In this study, we examined quality of life in AD patients managed through a direct-access online model. We randomized 156 patients to receiving care through a direct-access online platform or in person. Patients were seen for six visits over 12 months. At each visit, the patients completed Dermatology Life Quality Index/Children's Dermatology Life Quality Index (DLQI/CDLQI), and Short Form (SF-12). Between baseline and 12 months, the mean (standard deviation, SD) within-group difference in DLQI score in the online group was 4.1 (±2.3); for the in-person group, the within-group difference was 4.8 (±2.7). The mean (SD) within-group difference in CDLQI score in the online group was 4.7 (±2.8); for the in-person group, the within-group difference was 4.9 (±3.1). The mean (SD) within-group difference in physical component score (PCS) and mental component score (MCS) SF-12 scores in the online group was 6.5 (±3.8) and 8.6 (±4.3); for the in-person group, it was 6.8 (±3.2) and 9.1(±3.8), respectively. The difference in the change in DLQI, CDLQI, SF-12 PCS, and SF-12 MCS scores between the two groups was 0.72 (95% confidence interval [90% CI], -0.97 to 2.41), 0.23 (90% CI, -2.21 to 2.67), 0.34 (90% CI, -1.16 to 1.84), and 0.51 (90% CI, -1.11 to 2.13), respectively. All differences were contained within their equivalence margins. Adult and pediatric AD patients receiving direct-access online care had equivalent quality of life outcomes as those see in person. The direct-access online model has the potential to increase access to care for patients with chronic skin diseases.
Kornerup, Josefine S; Brodin, Patrik; Birk Christensen, Charlotte; Björk-Eriksson, Thomas; Kiil-Berthelsen, Anne; Borgwardt, Lise; Munck Af Rosenschöld, Per
2015-04-01
PET/CT may be more helpful than CT alone for radiation therapy planning, but the added risk due to higher doses of ionizing radiation is unknown. To estimate the risk of cancer induction and mortality attributable to the [F-18]2-fluoro-2-deoxyglucose (FDG) PET and CT scans used for radiation therapy planning in children with cancer, and compare to the risks attributable to the cancer treatment. Organ doses and effective doses were estimated for 40 children (2-18 years old) who had been scanned using PET/CT as part of radiation therapy planning. The risk of inducing secondary cancer was estimated using the models in BEIR VII. The prognosis of an induced cancer was taken into account and the reduction in life expectancy, in terms of life years lost, was estimated for the diagnostics and compared to the life years lost attributable to the therapy. Multivariate linear regression was performed to find predictors for a high contribution to life years lost from the radiation therapy planning diagnostics. The mean contribution from PET to the effective dose from one PET/CT scan was 24% (range: 7-64%). The average proportion of life years lost attributable to the nuclear medicine dose component from one PET/CT scan was 15% (range: 3-41%). The ratio of life years lost from the radiation therapy planning PET/CT scans and that of the cancer treatment was on average 0.02 (range: 0.01-0.09). Female gender was associated with increased life years lost from the scans (P < 0.001). Using FDG-PET/CT instead of CT only when defining the target volumes for radiation therapy of children with cancer does not notably increase the number of life years lost attributable to diagnostic examinations.
Support for life-cycle product reuse in NASA's SSE
NASA Technical Reports Server (NTRS)
Shotton, Charles
1989-01-01
The Software Support Environment (SSE) is a software factory for the production of Space Station Freedom Program operational software. The SSE is to be centrally developed and maintained and used to configure software production facilities in the field. The PRC product TTCQF provides for an automated qualification process and analysis of existing code that can be used for software reuse. The interrogation subsystem permits user queries of the reusable data and components which have been identified by an analyzer and qualified with associated metrics. The concept includes reuse of non-code life-cycle components such as requirements and designs. Possible types of reusable life-cycle components include templates, generics, and as-is items. Qualification of reusable elements requires analysis (separation of candidate components into primitives), qualification (evaluation of primitives for reusability according to reusability criteria) and loading (placing qualified elements into appropriate libraries). There can be different qualifications for different installations, methodologies, applications and components. Identifying reusable software and related components is labor-intensive and is best carried out as an integrated function of an SSE.
NASA Technical Reports Server (NTRS)
Jadaan, Osama M.; Powers, Lynn M.; Gyekenyesi, John P.
1997-01-01
The desirable properties of ceramics at high temperatures have generated interest in their use for structural applications such as in advanced turbine systems. Design lives for such systems can exceed 10,000 hours. Such long life requirements necessitate subjecting the components to relatively low stresses. The combination of high temperatures and low stresses typically places failure for monolithic ceramics in the creep regime. The objective of this work is to present a design methodology for predicting the lifetimes of structural components subjected to multiaxial creep loading. This methodology utilizes commercially available finite element packages and takes into account the time varying creep stress distributions (stress relaxation). In this methodology, the creep life of a component is divided into short time steps, during which, the stress and strain distributions are assumed constant. The damage, D, is calculated for each time step based on a modified Monkman-Grant creep rupture criterion. For components subjected to predominantly tensile loading, failure is assumed to occur when the normalized accumulated damage at any point in the component is greater than or equal to unity.
Vaccination and healthy aging.
Maggi, Stefania
2010-03-01
The aging process in humans is associated with a decrease in immune function (immunosenescence) and an increase in comorbid disorders. When combined with environmental factors this can lead to an increased risk and severity of infectious diseases. Diseases in older adults (>/=70 years) tend to be more severe and have a greater impact on health outcomes such as morbidity, disability, quality of life and mortality. However, some of the more common infections such as influenza and pneumococcal infection are vaccine preventable, but the uptake of such preventive strategies in adults has been poor. In this review some of the key clinical findings supporting the benefits of adult immunization are highlighted. Vaccination of the adult population needs to be a key component of a healthy aging strategy, since there is already convincing evidence that this approach can have an important impact on morbidity, mortality and quality of life.
NASA Technical Reports Server (NTRS)
Steele, John; Rector, tony; Gazda, Daniel; Lewis, John
2009-01-01
An EMU water processing kit (Airlock Coolant Loop Recovery A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. Conservative schedules for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. The examination of postflight samples and EMU hardware in November of 2006 indicated that the A/L CLR kits were functioning well and had excess capacity that would allow a relaxation of the initially conservative schedules of use and component life. A relaxed use schedule and list of component lives was implemented thereafter. Since the adoption of the relaxed A/L CLR schedules of use and component lives, several A/L CLR kit components, transport loop water samples and sensitive EMU transport loop components have been examined to gage the impact of the relaxed requirements. The intent of this paper is to summarize the findings of that evaluation, and to outline updated schedules for A/L CLR use and component life.
Space Shuttle Transportation (Roll-Out) Loads Diagnostics
NASA Technical Reports Server (NTRS)
Elliott, Kenny B.; Buehrle, Ralph D.; James, George H.; Richart, Jene A.
2005-01-01
The Space Transportation System (STS) consists of three primary components; an Orbiter Vehicle, an External Fuel Tank, and two Solid Rocket Boosters. The Orbiter Vehicle and Solid Rocket Boosters are reusable components, and as such, they are susceptible to durability issues. Recently, the fatigue load spectra for these components have been updated to include load histories acquired during the rollout phase of the STS processing for flight. Using traditional program life assessment techniques, the incorporation of these "rollout" loads produced unacceptable life estimates for certain Orbiter structural members. As a result, the Space Shuttle System Engineering and Integration Office has initiated a program to re-assess the method used for developing the "rollout" loads and performing the life assessments. In the fall of 2003 a set of tests were preformed to provide information to either validate existing load spectra estimation techniques or generate new load spectra estimation methods. Acceleration and strain data were collected from two rollouts of a partial-stack configuration of the Space Shuttle. The partial stack configuration consists of two Solid Rocket Boosters tied together at the upper External Tank attachment locations mounted on the Mobile Launch Platform carried by a Crawler Transporter (CT). In the current analysis, the data collected from this test is examined for consistency in speed, surface condition effects, and the characterization of the forcing function. It is observed that the speed of the CT is relatively stable. The dynamic response acceleration of the partial-stack is slightly sensitive to the surface condition of the road used for transport, and the dynamic response acceleration of the partial-stack generally increases as the transport speed increases. However, the speed sensitivity is dependent on the measurement location. Finally, the character of the forcing function is narrow-banded with the primary drivers being harmonics of two CT speed dependent excitations. One source is an excitation due to the CT treads striking the road surface, and the second is unknown.
Practical theories for service life prediction of critical aerospace structural components
NASA Technical Reports Server (NTRS)
Ko, William L.; Monaghan, Richard C.; Jackson, Raymond H.
1992-01-01
A new second-order theory was developed for predicting the service lives of aerospace structural components. The predictions based on this new theory were compared with those based on the Ko first-order theory and the classical theory of service life predictions. The new theory gives very accurate service life predictions. An equivalent constant-amplitude stress cycle method was proposed for representing the random load spectrum for crack growth calculations. This method predicts the most conservative service life. The proposed use of minimum detectable crack size, instead of proof load established crack size as an initial crack size for crack growth calculations, could give a more realistic service life.
Hybrid Modeling for Testing Intelligent Software for Lunar-Mars Closed Life Support
NASA Technical Reports Server (NTRS)
Malin, Jane T.; Nicholson, Leonard S. (Technical Monitor)
1999-01-01
Intelligent software is being developed for closed life support systems with biological components, for human exploration of the Moon and Mars. The intelligent software functions include planning/scheduling, reactive discrete control and sequencing, management of continuous control, and fault detection, diagnosis, and management of failures and errors. Four types of modeling information have been essential to system modeling and simulation to develop and test the software and to provide operational model-based what-if analyses: discrete component operational and failure modes; continuous dynamic performance within component modes, modeled qualitatively or quantitatively; configuration of flows and power among components in the system; and operations activities and scenarios. CONFIG, a multi-purpose discrete event simulation tool that integrates all four types of models for use throughout the engineering and operations life cycle, has been used to model components and systems involved in the production and transfer of oxygen and carbon dioxide in a plant-growth chamber and between that chamber and a habitation chamber with physicochemical systems for gas processing.
1999-03-01
cycle managers include (1) improving the durability of components through material substitution, or the addition of protective coatings, (2) returning... including in service trials, is required to demonstrate that the repaired and/or modified component is safe to use and remains so once returned to...Better Turbine Materials and Technology Including 5 Predicted Life Improvements by T.J. Williams Repair Developments to Fit Customer Needs (Presented
CARES/Life Ceramics Durability Evaluation Software Used for Mars Microprobe Aeroshell
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.
1998-01-01
The CARES/Life computer program, which was developed at the NASA Lewis Research Center, predicts the probability of a monolithic ceramic component's failure as a function of time in service. The program has many features and options for materials evaluation and component design. It couples commercial finite element programs-which resolve a component's temperature and stress distribution-to-reliability evaluation and fracture mechanics routines for modeling strength-limiting defects. These routines are based on calculations of the probabilistic nature of the brittle material's strength. The capability, flexibility, and uniqueness of CARES/Life has attracted many users representing a broad range of interests and has resulted in numerous awards for technological achievements and technology transfer.
NASA Technical Reports Server (NTRS)
Prince, R.; Knott, W.; Buchanan, Paul
1987-01-01
Design criteria for the Biomass Production Chamber (BPC), preliminary operating procedures, and requirements for the future development of the Controlled Ecological Life Support System (CELSS) are discussed. CELSS, which uses a bioregenerative system, includes the following three major units: (1) a biomass production component to grow plants under controlled conditions; (2) food processing components to derive maximum edible content from all plant parts; and (3) waste management components to recover and recycle all solids, liquids, and gases necessary to support life. The current status of the CELSS breadboard facility is reviewed; a block diagram of a simplified version of CELSS and schematic diagrams of the BPS are included.
Desensitization for Drug Hypersensitivity to Chemotherapy and Monoclonal Antibodies.
Bonamichi-Santos, Rafael; Castells, Mariana
2016-01-01
Chemotherapies drugs and monoclonal antibodies are key components of the treatment of cancer patients and patients with chronic inflammatory conditions to provide increase in life expectancy and quality of life. Their increased use has lead to an increase in drugs hypersensitivity reactions (DHR) worldwide. DHR to those agents prevented their use and promoted the use of second line therapies to protect patients' hypersensitive reactions and anaphylaxis. Second line medications may not fully address the patients' medical condition and it is desirable to keep patients on first line therapy. Drug hypersensitivity symptoms can range from mild cutaneous reactions to life-threatening anaphylaxis. Rapid drug desensitization (RDD) is a novel approach to the management of drug hypersensitivity reactions which are IgE and non-IgE mediated. Through the diferent desensitization protocols patients can receive the full dose of the medications that they have presented a hypersensitive reaction and been protected against anaphylaxis. This review looks at the current literature on hypersensitivity reactions (HSR) to chemotherapy drugs and monoclonal antibodies and the potential use of RDD for their management. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
2011-01-01
Background We investigate whether the changing environment caused by rapid economic growth yielded differential effects for successive Taiwanese generations on 8 components of metabolic syndrome (MetS): body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), triglycerides (TG), high-density lipoprotein (HDL), Low-density lipoproteins (LDL) and uric acid (UA). Methods To assess the impact of age, birth year and year of examination on MetS components, we used partial least squares regression to analyze data collected by Mei-Jaw clinics in Taiwan in years 1996 and 2006. Confounders, such as the number of years in formal education, alcohol intake, smoking history status, and betel-nut chewing were adjusted for. Results As the age of individuals increased, the values of components generally increased except for UA. Men born after 1970 had lower FPG, lower BMI, lower DBP, lower TG, Lower LDL and greater HDL; women born after 1970 had lower BMI, lower DBP, lower TG, Lower LDL and greater HDL and UA. There is a similar pattern between the trend in levels of metabolic syndrome components against birth year of birth and economic growth in Taiwan. Conclusions We found cohort effects in some MetS components, suggesting associations between the changing environment and health outcomes in later life. This ecological association is worthy of further investigation. PMID:21619595
A Cost-Utility Model of Care for Peristomal Skin Complications
Inglese, Gary; Manson, Andrea; Townshend, Arden
2016-01-01
PURPOSE: The aim of this study was to evaluate the economic and humanistic implications of using ostomy components to prevent subsequent peristomal skin complications (PSCs) in individuals who experience an initial, leakage-related PSC event. DESIGN: Cost-utility analysis. METHODS: We developed a simple decision model to consider, from a payer's perspective, PSCs managed with and without the use of ostomy components over 1 year. The model evaluated the extent to which outcomes associated with the use of ostomy components (PSC events avoided; quality-adjusted life days gained) offset the costs associated with their use. RESULTS: Our base case analysis of 1000 hypothetical individuals over 1 year assumes that using ostomy components following a first PSC reduces recurrent events versus PSC management without components. In this analysis, component acquisition costs were largely offset by lower resource use for ostomy supplies (barriers; pouches) and lower clinical utilization to manage PSCs. The overall annual average resource use for individuals using components was about 6.3% ($139) higher versus individuals not using components. Each PSC event avoided yielded, on average, 8 additional quality-adjusted life days over 1 year. CONCLUSIONS: In our analysis, (1) acquisition costs for ostomy components were offset in whole or in part by the use of fewer ostomy supplies to manage PSCs and (2) use of ostomy components to prevent PSCs produced better outcomes (fewer repeat PSC events; more health-related quality-adjusted life days) over 1 year compared to not using components. PMID:26633166
Ballen, Cissy J; Thompson, Seth K; Blum, Jessamina E; Newstrom, Nicholas P; Cotner, Sehoya
2018-01-01
Course-based undergraduate research experiences (CUREs) are a type of laboratory learning environment associated with a science course, in which undergraduates participate in novel research. According to Auchincloss et al. (CBE Life Sci Educ 2104; 13:29-40), CUREs are distinct from other laboratory learning environments because they possess five core design components, and while national calls to improve STEM education have led to an increase in CURE programs nationally, less work has specifically focused on which core components are critical to achieving desired student outcomes. Here we use a backward elimination experimental design to test the importance of two CURE components for a population of non-biology majors: the experience of discovery and the production of data broadly relevant to the scientific or local community. We found nonsignificant impacts of either laboratory component on students' academic performance, science self-efficacy, sense of project ownership, and perceived value of the laboratory experience. Our results challenge the assumption that all core components of CUREs are essential to achieve positive student outcomes when applied at scale.
Perspective of Membrane Technology in Dairy Industry: A Review
Kumar, Pavan; Sharma, Neelesh; Ranjan, Rajeev; Kumar, Sunil; Bhat, Z. F.; Jeong, Dong Kee
2013-01-01
Membrane technology has revolutionized the dairy sector. Different types of membranes are used in the industry for various purposes like extending the shelf life of milk without exposure to heat treatment, standardization of the major components of milk for tailoring new products as well increasing yield and quality of the dairy products, and concentrating, fractionation and purification of milk components especially valuable milk proteins in their natural state. In the cheese industry, membranes increase the yield and quality of cheese and control the whey volume, by concentrating the cheese milk. With the advancement of newer technology in membrane processes, it is possible to recover growth factor from whey. With the introduction of superior quality membranes as well as newer technology, the major limitation of membranes, fouling or blockage has been overcome to a greater extent. PMID:25049918
Data and monitoring needs for a more ecological agriculture
NASA Astrophysics Data System (ADS)
Zaks, David P. M.; Kucharik, Christopher J.
2011-01-01
Information on the life-cycle environmental impacts of agricultural production is often limited. As demands grow for increasing agricultural output while reducing its negative environmental impacts, both existing and novel data sources can be leveraged to provide more information to producers, consumers, scientists and policy makers. We review the components and organization of an agroecological sensor web that integrates remote sensing technologies and in situ sensors with models in order to provide decision makers with effective management options at useful spatial and temporal scales for making more informed decisions about agricultural productivity while reducing environmental burdens. Several components of the system are already in place, but by increasing the extent and accessibility of information, decision makers will have the opportunity to enhance food security and environmental quality. Potential roadblocks to implementation include farmer acceptance, data transparency and technology deployment.
Papaleo, Francesco; Silverman, Jill L.; Aney, Jordan; Tian, Qingjun; Barkan, Charlotte L.; Chadman, Kathryn K.; Crawley, Jacqueline N.
2011-01-01
BDNF regulates components of cognitive processes and has been implicated in psychiatric disorders. Here we report that genetic overexpression of the BDNF mature isoform (BDNF-tg) in female mice impaired working memory functions while sparing components of fear conditioning. BDNF-tg mice also displayed reduced breeding efficiency, higher anxiety-like scores, high self-grooming, impaired prepulse inhibition, and higher susceptibility to seizures when placed in a new empty cage, as compared with wild-type (WT) littermate controls. Control measures of general health, locomotor activity, motor coordination, depression-related behaviors, and sociability did not differ between genotypes. The present findings, indicating detrimental effects of life-long increased BDNF in mice, may inform human studies evaluating the role of BDNF functional genetic variations on cognitive abilities and vulnerability to psychiatric disorders. PMID:21791566
Perspective of membrane technology in dairy industry: a review.
Kumar, Pavan; Sharma, Neelesh; Ranjan, Rajeev; Kumar, Sunil; Bhat, Z F; Jeong, Dong Kee
2013-09-01
Membrane technology has revolutionized the dairy sector. Different types of membranes are used in the industry for various purposes like extending the shelf life of milk without exposure to heat treatment, standardization of the major components of milk for tailoring new products as well increasing yield and quality of the dairy products, and concentrating, fractionation and purification of milk components especially valuable milk proteins in their natural state. In the cheese industry, membranes increase the yield and quality of cheese and control the whey volume, by concentrating the cheese milk. With the advancement of newer technology in membrane processes, it is possible to recover growth factor from whey. With the introduction of superior quality membranes as well as newer technology, the major limitation of membranes, fouling or blockage has been overcome to a greater extent.
Trombetti, A; Reid, K F; Hars, M; Herrmann, F R; Pasha, E; Phillips, E M; Fielding, R A
2016-02-01
This 3-year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of life. Our findings reinforce the importance of preserving muscle health with advancing age. The age-associated loss of skeletal muscle quantity and function are critical determinants of independent physical functioning in later life. Longitudinal studies investigating how decrements in muscle components of sarcopenia impact fear of falling (FoF) and quality of life (QoL) in older adults are lacking. Twenty-six healthy older subjects (age, 74.1 ± 3.7; Short Physical Performance Battery (SPPB) score ≥10) and 22 mobility-limited older subjects (age, 77.2 ± 4.4; SPPB score ≤9) underwent evaluations of lower extremity muscle size and composition by computed tomography, strength and power, and physical performance at baseline and after 3-year follow-up. The Falls Efficacy Scale (FES) and Short Form-36 questionnaire (SF-36) were also administered at both timepoints to assess FoF and QoL, respectively. At 3-year follow-up, muscle cross-sectional area (CSA) (p < 0.013) and power decreased (p < 0.001), while intermuscular fat infiltration increased (p < 0.001). These decrements were accompanied with a longer time to complete 400 m by 22 ± 46 s (p < 0.002). Using linear mixed-effects regression models, declines of muscle CSA, strength and power, and SPPB score were associated with increased FES score (p < 0.05 for each model). Reduced physical component summary score of SF-36 over follow-up was independently associated with decreased SPPB score (p < 0.020), muscle CSA (p < 0.046), and increased 400 m walk time (p < 0.003). In older adults with and without mobility limitations, declining muscle mass, strength, power, and physical performance contribute independently to increase FoF, while declines of muscle mass and physical performance contribute to deterioration of QoL. These findings provide further rationale for developing interventions to improve aging muscle health.
Potential benefits of a ceramic thermal barrier coating on large power generation gas turbine
NASA Technical Reports Server (NTRS)
Clark, J. S.; Nainiger, J. J.
1977-01-01
Thermal barrier coating design option offers benefit in terms of reduced electricity costs when used in utility gas turbines. Options considered include: increased firing temperature, increased component life, reduced cooling air requirements, and increased corrosion resistance (resulting in increased tolerance for dirty fuels). Performance and cost data were obtained. Simple, recuperated and combined cycle applications were considered, and distillate and residual fuels were assumed. The results indicate that thermal barrier coatings could produce large electricity cost savings if these coatings permit turbine operation with residual fuels at distillate-rated firing temperatures. The results also show that increased turbine inlet temperature can result in substantial savings in fuel and capital costs.
Angott, Andrea M.; Comerford, David A.; Ubel, Peter A.
2014-01-01
Objective To test a video intervention as a way to improve predictions of mood and quality-of-life with an emotionally evocative medical condition. Such predictions are typically inaccurate, which can be consequential for decision making. Method In Part 1, people presently or formerly living with ostomies predicted how watching a video depicting a person changing his ostomy pouch would affect mood and quality-of-life forecasts for life with an ostomy. In Part 2, participants from the general public read a description about life with an ostomy; half also watched a video depicting a person changing his ostomy pouch. Participants’ quality-of-life and mood forecasts for life with an ostomy were assessed. Results Contrary to our expectations, and the expectations of people presently or formerly living with ostomies, the video did not reduce mood or quality-of-life estimates, even among participants high in trait disgust sensitivity. Among low-disgust participants, watching the video increased quality-of-life predictions for ostomy. Conclusion Video interventions may improve mood and quality-of-life forecasts for medical conditions, including those that may elicit disgust, such as ostomy. Practice implications Video interventions focusing on patients’ experience of illness continue to show promise as components of decision aids, even for emotionally charged health states such as ostomy. PMID:23177398
Evaluation of Navy 9 cst Oil in Bell Helicopter M412 HP Gearboxes
NASA Technical Reports Server (NTRS)
Zachary, S. H.; Stapper, William R.
1998-01-01
Tests were conducted with 5 and 9 centistoke lubricants in three different helicopter gearboxes, a main transmission, a 42' gearbox and a tailrotor gearbox. The objective of the tests was to observe and measure the difference in the performance of the lubrication systems due to the viscosity difference between the two test lubricants. The 9 centistoke oil has been developed to provide higher component film thickness, increased load carrying capacity and improved corrosion resistance which will provide increased life for drive system gears and bearings.
Conflict resolution: critical to productive schools of nursing.
Littlefield, V M
1995-01-01
Conflict, a normal component of university life, is enhanced in today's schools of nursing because of declining resources and increased expectations of faculty. Management of conflict for positive change and increased productivity is essential for academic leaders. A variety of strategies to diagnose, confront, and resolve conflict are important resources to facilitate change and allow faculty and administrators to respond to new opportunities and challenges. Collaboration and win/win strategies are ideal, but not always possible. Alternative approaches to confront destructive conflict, yet present options that benefit individuals as well as schools are also essential.
Welsh, Lynn
2017-05-01
To analyse current evidence on the efficacy of bandage systems containing both elastic and inelastic components (mixed-component systems). International consensus on the efficacy of types of compression systems is difficult to achieve; however, mixed-component systems are being promoted as combining the best properties of both elastic and inelastic bandage systems and increasingly being used to treat venous leg ulcers in practice. A systematic literature review. Search terms such as venous leg ulcer, varicose ulcer, leg ulcer, compression, bandage, elastic, inelastic, short stretch, healing rate, interface pressure, mixed component, two-layer, four-layer and multi-layer were used in database and hand searches in several combinations. Limits were set for years 2005-March 2015 and English-language publications. A total of 475 studies were identified at initial search, and following elimination from abstract and title, this was reduced to 7. A further study was identified on Google Scholar, bringing the final number of studies fitting inclusion criteria to 8. The following subgroups relating to outcomes of efficacy were identified: ulcer healing, maintenance of interface pressure, slippage, ease of application and patient quality of life. Mixed-component systems were found to have comparable ulcer healing rates to alternative compression systems and be easy to apply; have similar abilities to maintain pressure as four-layer bandages and better abilities than short-stretch bandages; have less slippage than alternative systems; and to be significantly associated with several favourable quality of life outcomes. Clinician skill in bandage application was an uncontrolled variable in all eight papers included in the review, which may limit reliability of findings. This review synthesises existing evidence on the efficacy of mixed-component systems and encourages clinicians to regard them as an effective alternative to purely elastic or inelastic compression systems. Additionally, it highlights the importance of clinician skill in bandage application as a crucial determinant of effective compression. © 2016 John Wiley & Sons Ltd.
Investigating the road surface effect to the fatigue life of an automotive coil spring
NASA Astrophysics Data System (ADS)
Putra, T. E.; Husaini
2018-05-01
This work aims to estimate the life of a coil spring considering road surface profiles. Strain signals were measured by installing a strain gage at the highest stress location of the coil spring and then driving the vehicle on country and village roads. The village road gave high amplitudes containing spikes when the tire touched a curb, bump or pothole. These conditions contributed to a higher loading rate to the car component, contributing to shorter useful fatigue life, which was only 140 reversals of blocks. Driving on the village road resulted in a 6-times decrease in the useful fatigue life of the component in comparison to the country road. In conclusion, the village road caused stronger vibrations to the component because it has a rough surface; meanwhile, the country road provided lower vibrations because the road was smooth.
Life and reliability models for helicopter transmissions
NASA Technical Reports Server (NTRS)
Savage, M.; Knorr, R. J.; Coy, J. J.
1982-01-01
Computer models of life and reliability are presented for planetary gear trains with a fixed ring gear, input applied to the sun gear, and output taken from the planet arm. For this transmission the input and output shafts are co-axial and the input and output torques are assumed to be coaxial with these shafts. Thrust and side loading are neglected. The reliability model is based on the Weibull distributions of the individual reliabilities of the in transmission components. The system model is also a Weibull distribution. The load versus life model for the system is a power relationship as the models for the individual components. The load-life exponent and basic dynamic capacity are developed as functions of the components capacities. The models are used to compare three and four planet, 150 kW (200 hp), 5:1 reduction transmissions with 1500 rpm input speed to illustrate their use.
Gray, David B; Hollingsworth, Holly H; Stark, Susan L; Morgan, Kerri A
2006-02-01
To describe the development and psychometric properties of a self-report survey of participation by people with mobility limitations, the Participation Survey/Mobility (PARTS/M). The information obtained during interviews and focus groups was used to develop items for the PARTS/M. Demographics and measures of disability, health, and functioning were collected. The PARTS/M was administered twice. Primarily in the midwestern United States. Purposeful sample of 604 people with mobility limitations having a diagnosis of spinal cord injury, multiple sclerosis, cerebral palsy, stroke, or postpoliomyelitis. Not applicable. PARTS/M is composed of 20 major life activities that are placed in 6 domains used in the activity/participation component of the International Classification of Functioning, Disability and Health: self-care; mobility; domestic life; interpersonal interactions and relationships; major life areas; and community, social, and civic life. For each activity, questions were asked about components of participation including frequency, health-related limitations, importance, choice, satisfaction, use of assistive technology, and use of personal assistance. PARTS/M domains and components of participation had good internal consistency and stability. Composite participation scores were developed for participation components and domains. PARTS/M is a reliable measure of some aspects of participation in major life activities for people with mobility impairments and limitations living in community settings.
NASALIFE - Component Fatigue and Creep Life Prediction Program
NASA Technical Reports Server (NTRS)
Gyekenyesi, John Z.; Murthy, Pappu L. N.; Mital, Subodh K.
2014-01-01
NASALIFE is a life prediction program for propulsion system components made of ceramic matrix composites (CMC) under cyclic thermo-mechanical loading and creep rupture conditions. Although the primary focus was for CMC components, the underlying methodologies are equally applicable to other material systems as well. The program references empirical data for low cycle fatigue (LCF), creep rupture, and static material properties as part of the life prediction process. Multiaxial stresses are accommodated by Von Mises based methods and a Walker model is used to address mean stress effects. Varying loads are reduced by the Rainflow counting method or a peak counting type method. Lastly, damage due to cyclic loading and creep is combined with Minor's Rule to determine damage due to cyclic loading, damage due to creep, and the total damage per mission and the number of potential missions the component can provide before failure.
Increased Reliability of Gas Turbine Components by Robust Coatings Manufacturing
NASA Astrophysics Data System (ADS)
Sharma, A.; Dudykevych, T.; Sansom, D.; Subramanian, R.
2017-08-01
The expanding operational windows of the advanced gas turbine components demand increasing performance capability from protective coating systems. This demand has led to the development of novel multi-functional, multi-materials coating system architectures over the last years. In addition, the increasing dependency of components exposed to extreme environment on protective coatings results in more severe penalties, in case of a coating system failure. This emphasizes that reliability and consistency of protective coating systems are equally important to their superior performance. By means of examples, this paper describes the effects of scatter in the material properties resulting from manufacturing variations on coating life predictions. A strong foundation in process-property-performance correlations as well as regular monitoring and control of the coating process is essential for robust and well-controlled coating process. Proprietary and/or commercially available diagnostic tools can help in achieving these goals, but their usage in industrial setting is still limited. Various key contributors to process variability are briefly discussed along with the limitations of existing process and product control methods. Other aspects that are important for product reliability and consistency in serial manufacturing as well as advanced testing methodologies to simplify and enhance product inspection and improve objectivity are briefly described.
Exploring Oral Cancer Patients' Preference in Medical Decision Making and Quality of Life.
Cheng, Sun-Long; Liao, Hsien-Hua; Shueng, Pei-Wei; Lee, Hsi-Chieh; Cheewakriangkrai, Chalong; Chang, Chi-Chang
2017-01-01
Little is known about the clinical effects of shared medical decision making (SMDM) associated with quality of life about oral cancer? To understand patients who occurred potential cause of SMDM and extended to explore the interrelated components of quality of life for providing patients with potential adaptation of early assessment. All consenting patients completed the SMDM questionnaire and 36-Item Short Form (SF-36). Regression analyses were conducted to find predictors of quality of life among oral cancer patients. The proposed model predicted 57.4% of the variance in patients' SF-36 Mental Component scores. Patient mental component summary scores were associated with smoking habit (β=-0.3449, p=0.022), autonomy (β=-0.226, p=0.018) and Control preference (β=-0.388, p=0.007). The proposed model predicted 42.6% of the variance in patients' SF-36 Physical component scores. Patient physical component summary scores were associated with higher education (β=0.288, p=0.007), employment status (β=-0.225, p=0.033), involvement perceived (β=-0.606, p=0.011) and Risk communication (β=-0.558, p=0.019). Future research is necessary to determine whether oral cancer patients would benefit from early screening and intervention to address shared medical decision making.
Labeled line drawing of launch and entry suit identifies various components
NASA Technical Reports Server (NTRS)
1988-01-01
Line drawings illustrate the front and back of the space shuttle launch and entry suit (LES) and labels identify various components. LES was designed for STS-26, the return to flight mission, and subsequent missions. Included in the crew escape system (CES) package are launch and entry helmet (LEH) with communications carrier (COMM CAP), parachute pack and harness, life preserver unit (LPU), life raft unit (LRU), LES gloves, suit oxygen manifold and valves, boots, and survival gear. Details of larger components are also identified.
Labeled line drawing of launch and entry suit identifies various components
1988-09-22
Line drawings illustrate the front and back of the space shuttle launch and entry suit (LES) and labels identify various components. LES was designed for STS-26, the return to flight mission, and subsequent missions. Included in the crew escape system (CES) package are launch and entry helmet (LEH) with communications carrier (COMM CAP), parachute pack and harness, life preserver unit (LPU), life raft unit (LRU), LES gloves, suit oxygen manifold and valves, boots, and survival gear. Details of larger components are also identified.
The quality of life among coronary heart disease patients at a teaching hospital.
Ho, S E; Ting, C K; Das, S; Loo, C Y; Rohayu, A B; Khor, S Y; Hamidah, H; Samsiah, M; Jeliha, J
2011-01-01
Quality of life after acute coronary heart disease amongst patients is important outcome factor in deliberations of patient's care. The main aim of the study was to examine the quality of life amongst acute CHD patients. A cross sectional descriptive study was conducted after an acute attack amongst coronary heart disease (CHD) patients in Universiti Kebangsaan Malaysia Medical Centre (UKMMC).The Medical Outcomes Short Form 36 (SF-36) comprised of 36 items used to measure quality of life which comprised of 4 domains of physical component summary were physical function, role physical, bodily pain, and general health and 4 domains of mental component summary were vitality, social function, emotional role, and mental health. A total of 108 respondents were recruited for this study. The findings showed that CHD. Respondents possessed good level of quality of life with total score of (59 ± 22). The total score of physical domain had mean and SD of 56 ± 24, while the total scores of the mental domain had mean and SD of 62 ± 27. There were significant differences between the general health components of quality of life with educational status of the CHD patients with (F= 5.433, p<0.05). There were significant differences in role physical components of quality of life with income (F= 3.144, p<0.05). The cardiac rehabilitation program would have deliberately improved their needs and conditions whilst hospitalization. These results have implications in which CHD patients should be evaluated with regard to their continuity of care.
2013-01-01
Background The effectiveness of microprocessor-controlled prosthetic knee joints (MPKs) has been assessed using a variety of outcome measures in a variety of health and health-related domains. However, if the patient is to receive a prosthetic knee joint that enables him to function optimally in daily life, it is vital that the clinician has adequate information about the effects of that particular component on all aspects of persons’ functioning. Especially information concerning activities and participation is of high importance, as this component of functioning closely describes the person’s ability to function with the prosthesis in daily life. The present study aimed to review the outcome measures that have been utilized to assess the effects of microprocessor-controlled prosthetic knee joints (MPK), in comparison with mechanically controlled prosthetic knee joints, and aimed to classify these measures according to the components and categories of functioning defined by the International Classification of Functioning, Disability and Health (ICF). Subsequently, the gaps in the scientific evidence regarding the effectiveness of MPKs were determined. Methods A systematic literature search in 6 databases (i.e. PubMed, CINAHL, Cochrane Library, Embase, Medline and PsychInfo) identified scientific studies that compared the effects of using MPKs with mechanically controlled prosthetic knee joints on persons’ functioning. The outcome measures that have been utilized in those studies were extracted and categorized according to the ICF framework. Also, a descriptive analysis regarding all studies has been performed. Results A total of 37 studies and 72 outcome measures have been identified. The majority (67%) of the outcome measures that described the effects of using an MPK on persons’ actual performance with the prosthesis covered the ICF body functions component. Only 31% of the measures on persons’ actual performance investigated how an MPK may affect performance in daily life. Research also typically focused on young, fit and active persons. Conclusions Scientifically valid evidence regarding the performance of persons with an MPK in everyday life is limited. Future research should specifically focus on activities and participation to increase the understanding of the possible functional added value of MPKs. PMID:24279314
Theeven, Patrick J R; Hemmen, Bea; Brink, Peter R G; Smeets, Rob J E M; Seelen, Henk A M
2013-11-27
The effectiveness of microprocessor-controlled prosthetic knee joints (MPKs) has been assessed using a variety of outcome measures in a variety of health and health-related domains. However, if the patient is to receive a prosthetic knee joint that enables him to function optimally in daily life, it is vital that the clinician has adequate information about the effects of that particular component on all aspects of persons' functioning. Especially information concerning activities and participation is of high importance, as this component of functioning closely describes the person's ability to function with the prosthesis in daily life. The present study aimed to review the outcome measures that have been utilized to assess the effects of microprocessor-controlled prosthetic knee joints (MPK), in comparison with mechanically controlled prosthetic knee joints, and aimed to classify these measures according to the components and categories of functioning defined by the International Classification of Functioning, Disability and Health (ICF). Subsequently, the gaps in the scientific evidence regarding the effectiveness of MPKs were determined. A systematic literature search in 6 databases (i.e. PubMed, CINAHL, Cochrane Library, Embase, Medline and PsychInfo) identified scientific studies that compared the effects of using MPKs with mechanically controlled prosthetic knee joints on persons' functioning. The outcome measures that have been utilized in those studies were extracted and categorized according to the ICF framework. Also, a descriptive analysis regarding all studies has been performed. A total of 37 studies and 72 outcome measures have been identified. The majority (67%) of the outcome measures that described the effects of using an MPK on persons' actual performance with the prosthesis covered the ICF body functions component. Only 31% of the measures on persons' actual performance investigated how an MPK may affect performance in daily life. Research also typically focused on young, fit and active persons. Scientifically valid evidence regarding the performance of persons with an MPK in everyday life is limited. Future research should specifically focus on activities and participation to increase the understanding of the possible functional added value of MPKs.
Redesign of Denggung Park as Sleman Urban Park based on Local Wisdom in Yogyakarta
NASA Astrophysics Data System (ADS)
Sanjaya, I.; Fatimah, IS
2017-10-01
Sleman Regency is one of the administrative area in Special Region of Yogyakarta Province which has increased the pace of infrastructure development activities that undertaken by the central government affects another surrounding area. The pace of infrastructure development impacts such problems in Sleman Regency such as, increasingly limited public spaces and changes in understanding the value of local wisdom. Sleman Regency has a park located in central government which is Denggung Park. This park has low visitors and less of aesthetic value which require re-design to improve the quality as public space for cultural identity space. The base concept of Urban Park adopted the philosophy that connects to four components in Javanese mythology. The four components in Javanese mythology symbolize the journey of human life in the Javanese cosmological theory, there are Mount Merapi, Keraton, Krapyak Stage, and South seas. The design concept inspired from pattern of Yogyakarta traditional clothing namely, Batik Kawung which describe of Philosophy “Four of Brotherhood and Five of Central itself” by means synergize four items creating world nature and human as life catalyzer. This study uses descriptive and spatial analysis method. The result of this research is expected to be a design recommendation for Sleman Regency governance in the urban park development.
PSHFT - COMPUTERIZED LIFE AND RELIABILITY MODELLING FOR TURBOPROP TRANSMISSIONS
NASA Technical Reports Server (NTRS)
Savage, M.
1994-01-01
The computer program PSHFT calculates the life of a variety of aircraft transmissions. A generalized life and reliability model is presented for turboprop and parallel shaft geared prop-fan aircraft transmissions. The transmission life and reliability model is a combination of the individual reliability models for all the bearings and gears in the main load paths. The bearing and gear reliability models are based on the statistical two parameter Weibull failure distribution method and classical fatigue theories. The computer program developed to calculate the transmission model is modular. In its present form, the program can analyze five different transmissions arrangements. Moreover, the program can be easily modified to include additional transmission arrangements. PSHFT uses the properties of a common block two-dimensional array to separate the component and transmission property values from the analysis subroutines. The rows correspond to specific components with the first row containing the values for the entire transmission. Columns contain the values for specific properties. Since the subroutines (which determine the transmission life and dynamic capacity) interface solely with this property array, they are separated from any specific transmission configuration. The system analysis subroutines work in an identical manner for all transmission configurations considered. Thus, other configurations can be added to the program by simply adding component property determination subroutines. PSHFT consists of a main program, a series of configuration specific subroutines, generic component property analysis subroutines, systems analysis subroutines, and a common block. The main program selects the routines to be used in the analysis and sequences their operation. The series of configuration specific subroutines input the configuration data, perform the component force and life analyses (with the help of the generic component property analysis subroutines), fill the property array, call up the system analysis routines, and finally print out the analysis results for the system and components. PSHFT is written in FORTRAN 77 and compiled on a MicroSoft FORTRAN compiler. The program will run on an IBM PC AT compatible with at least 104k bytes of memory. The program was developed in 1988.
The Importance of Engine External's Health
NASA Technical Reports Server (NTRS)
Stoner, Barry L.
2006-01-01
Engine external components include all the fluid carrying, electron carrying, and support devices that are needed to operate the propulsion system. These components are varied and include: pumps, valves, actuators, solenoids, sensors, switches, heat exchangers, electrical generators, electrical harnesses, tubes, ducts, clamps and brackets. The failure of any component to perform its intended function will result in a maintenance action, a dispatch delay, or an engine in flight shutdown. The life of each component, in addition to its basic functional design, is closely tied to its thermal and dynamic environment .Therefore, to reach a mature design life, the component's thermal and dynamic environment must be understood and controlled, which can only be accomplished by attention to design analysis and testing. The purpose of this paper is to review analysis and test techniques toward achieving good component health.
Kim, Hyung Chul; Wallington, Timothy J; Sullivan, John L; Keoleian, Gregory A
2015-08-18
Lightweighting is a key strategy to improve vehicle fuel economy. Assessing the life-cycle benefits of lightweighting requires a quantitative description of the use-phase fuel consumption reduction associated with mass reduction. We present novel methods of estimating mass-induced fuel consumption (MIF) and fuel reduction values (FRVs) from fuel economy and dynamometer test data in the U.S. Environmental Protection Agency (EPA) database. In the past, FRVs have been measured using experimental testing. We demonstrate that FRVs can be mathematically derived from coast down coefficients in the EPA vehicle test database avoiding additional testing. MIF and FRVs calculated for 83 different 2013 MY vehicles are in the ranges 0.22-0.43 and 0.15-0.26 L/(100 km 100 kg), respectively, and increase to 0.27-0.53 L/(100 km 100 kg) with powertrain resizing to retain equivalent vehicle performance. We show how use-phase fuel consumption can be estimated using MIF and FRVs in life cycle assessments (LCAs) of vehicle lightweighting from total vehicle and vehicle component perspectives with, and without, powertrain resizing. The mass-induced fuel consumption model is illustrated by estimating lifecycle greenhouse gas (GHG) emission benefits from lightweighting a grille opening reinforcement component using magnesium or carbon fiber composite for 83 different vehicle models.
Endocrine Disruptors and the Breast: Early Life Effects and Later Life Disease
Macon, Madisa B.
2013-01-01
Breast cancer risk has both heritable and environment/lifestyle components. The heritable component is a small contribution (5–27 %), leaving the majority of risk to environment (e.g., applied chemicals, food residues, occupational hazards, pharmaceuticals, stress) and lifestyle (e.g., physical activity, cosmetics, water source, alcohol, smoking). However, these factors are not well-defined, primarily due to the enormous number of factors to be considered. In both humans and rodent models, environmental factors that act as endocrine disrupting compounds (EDCs) have been shown to disrupt normal mammary development and lead to adverse lifelong consequences, especially when exposures occur during early life. EDCs can act directly or indirectly on mammary tissue to increase sensitivity to chemical carcinogens or enhance development of hyperplasia, beaded ducts, or tumors. Protective effects have also been reported. The mechanisms for these changes are not well understood. Environmental agents may also act as carcinogens in adult rodent models, directly causing or promoting tumor development, typically in more than one organ. Many of the environmental agents that act as EDCs and are known to affect the breast are discussed. Understanding the mechanism(s) of action for these compounds will be critical to prevent their effects on the breast in the future. PMID:23417729
Endocrine disruptors and the breast: early life effects and later life disease.
Macon, Madisa B; Fenton, Suzanne E
2013-03-01
Breast cancer risk has both heritable and environment/lifestyle components. The heritable component is a small contribution (5-27 %), leaving the majority of risk to environment (e.g., applied chemicals, food residues, occupational hazards, pharmaceuticals, stress) and lifestyle (e.g., physical activity, cosmetics, water source, alcohol, smoking). However, these factors are not well-defined, primarily due to the enormous number of factors to be considered. In both humans and rodent models, environmental factors that act as endocrine disrupting compounds (EDCs) have been shown to disrupt normal mammary development and lead to adverse lifelong consequences, especially when exposures occur during early life. EDCs can act directly or indirectly on mammary tissue to increase sensitivity to chemical carcinogens or enhance development of hyperplasia, beaded ducts, or tumors. Protective effects have also been reported. The mechanisms for these changes are not well understood. Environmental agents may also act as carcinogens in adult rodent models, directly causing or promoting tumor development, typically in more than one organ. Many of the environmental agents that act as EDCs and are known to affect the breast are discussed. Understanding the mechanism(s) of action for these compounds will be critical to prevent their effects on the breast in the future.
NASA Astrophysics Data System (ADS)
Granados-Alejo, V.; Rubio-González, C.; Vázquez-Jiménez, C. A.; Banderas, J. A.; Gómez-Rosas, G.
2018-05-01
The influence of specimen thickness on the fatigue crack initiation of 2205 duplex stainless steel notched specimens subjected to laser shock peening (LSP) was investigated. The purpose was to examine the effectiveness of LSP on flat components with different thicknesses. For the LSP treatment a Nd:YAG pulsed laser operating at 10 Hz with 1064 nm of wavelength was used; pulse density was 2500 pulses/cm2. The LSP setup was the waterjet arrangement without sample coating. Residual stress distribution as a function of depth was determined by the hole drilling method. Notched specimens 2, 3 and 4 mm thick were LSP treated on both faces and then fatigue loading was applied with R = 0.1. Experimental fatigue lives were compared with life predictions from finite element simulation. A good comparison of the predicted and experimental fatigue lives was observed. LSP finite element simulation helps in explaining the influence of thickness on fatigue lives in terms of equivalent plastic strain distribution variations associated with the change in thickness. It is demonstrated that specimen size effect is an important issue in applying LSP on real components. Reducing the specimen thickness, the fatigue life improvement induced by LSP is significantly increased. Fatigue life extension up to 300% is observed on thin specimens with LSP.
Life Support Filtration System Trade Study for Deep Space Missions
NASA Technical Reports Server (NTRS)
Agui, Juan H.; Perry, Jay L.
2017-01-01
The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed.
Sperduti, Marco; Makowski, Dominique; Piolino, Pascale
2016-11-01
Life expectancy is constantly increasing. However, a longer life not always corresponds to a healthier life. Indeed, even normal aging is associated with a decline in different cognitive functions. It has been proposed that a central mechanism that could contribute to this widespread cognitive decline is an ineffective inhibitory attentional control. Meditation, to the other hand, has been associated, in young adults, to enhancement of several attentional processes. Nevertheless, attention is not a unitary construct. An influent model proposed the distinction of three subsystems: the alerting (the ability to reach and maintain a vigilance state), the orienting (the capacity of focusing attention on a subset of stimuli), and the conflict resolution or executive component (the ability to resolve conflict or allocate limited resources between competing stimuli). Here, we investigated, employing the Attentional Network Task (ANT), the specific impact of age on these three subcomponents, and the protective role of long-term meditation testing a group of older adults naïve to meditation, a group of age-matched adults with long-term practice of meditation, and a group of young adults with no previous meditation experience. We reported a specific decline of the efficiency of the executive component in elderly that was not observed in age-matched meditators. Our results are encouraging for the investigation of the potential beneficial impact of meditation on other cognitive processes that decline in aging such as memory. Moreover, they could inform geriatric healthcare prevention and intervention strategies, proposing a new approach for cognitive remediation in elderly populations.
Neonatal mortality in Argentina. Situation analysis from 2005 to 2014.
Finkelstein, Juliana Z; Duhau, Mariana; Fasola, María L; Escobar, Paola
2017-08-01
Neonatal mortality (NM) refers to deaths occurring between birth and 27 days of life. This component of infant mortality has shown the least reduction over the past 50 years. The objective of this study was to analyze the course and characteristics of NM in Argentina. This was a descriptive, ecological study of NM in Argentina conducted between 2005 and 2014 to analyze its course, causes, and the relevance of prematurity and a low birth weight. Records of the Health Statistics and Information Department of the Ministry of Health of Argentina were used. The neonatal mortality rate reduced by 19.2% (2005: 8.9‰; 2014: 7.2‰); the early component (between birth and 6 days of life), by 20% (2005: 6.5‰; 2014: 5.2‰); and the late component (between 7 and 27 days of life), by 13% (2005: 2.3‰; 2014: 2‰). Disorders originating in the perinatal period and congenital malformations were the cause of more than 95% of neonatal deaths in this period. The relative significance of disorders originating in the perinatal period reduced, but that of congenital malformations increased. Preterm and low birth weight live births had the greatest risk of neonatal death. A younger gestational age and a lower birth weight resulted in a lower reduction of specific neonatal mortality rate. In the past 10 years, NM has reduced significantly. Disorders originating in the perinatal period and congenital malformations were the cause of almost all deaths in this age group. NM was associated with a low birth weight and prematurity. Sociedad Argentina de Pediatría
Reliability and Creep/Fatigue Analysis of a CMC Component
NASA Technical Reports Server (NTRS)
Murthy, Pappu L. N.; Mital, Subodh K.; Gyekenyesi, John Z.; Gyekenyesi, John P.
2007-01-01
High temperature ceramic matrix composites (CMC) are being explored as viable candidate materials for hot section gas turbine components. These advanced composites can potentially lead to reduced weight and enable higher operating temperatures requiring less cooling; thus leading to increased engine efficiencies. There is a need for convenient design tools that can accommodate various loading conditions and material data with their associated uncertainties to estimate the minimum predicted life as well as the failure probabilities of a structural component. This paper presents a review of the life prediction and probabilistic analyses performed for a CMC turbine stator vane. A computer code, NASALife, is used to predict the life of a 2-D woven silicon carbide fiber reinforced silicon carbide matrix (SiC/SiC) turbine stator vane due to a mission cycle which induces low cycle fatigue and creep. The output from this program includes damage from creep loading, damage due to cyclic loading and the combined damage due to the given loading cycle. Results indicate that the trends predicted by NASALife are as expected for the loading conditions used for this study. In addition, a combination of woven composite micromechanics, finite element structural analysis and Fast Probability Integration (FPI) techniques has been used to evaluate the maximum stress and its probabilistic distribution in a CMC turbine stator vane. Input variables causing scatter are identified and ranked based upon their sensitivity magnitude. Results indicate that reducing the scatter in proportional limit strength of the vane material has the greatest effect in improving the overall reliability of the CMC vane.
The Subjective Quality of Life in Young People With Tourette Syndrome in China.
Liu, Shiguo; Zheng, Lanlan; Zheng, Xueping; Zhang, Xinhua; Yi, Mingji; Ma, Xu
2017-03-01
To explore the subjective quality of life (QoL) in children with Tourette Syndrome (TS) in China to provide a basis for more effective interference. A total of 107 patients and 107 controls were enrolled. Subjective QoL was investigated by Inventory of Subjective Life Quality, Family Environment Scale of Chinese Version, and the Yale Global Tic Severity Scale, and a case-control study was performed. The total score of subjective QoL and family life, school life, peer relationship, cognitive component, environment, self-awareness, cognitive component and depression experience in the TS were lower than control. Patients with co-morbid exhibited significantly lower scores within the subjective QoL family life, peer relationship, school life, self-awareness, and cognitive affective domains. The subjective QoL is impaired and it is important to control clinical symptoms and improve family environment for the improvement of the subjective QoL in TS.
Humor and creative life styles.
Richman, J
2001-01-01
This paper is based upon the writings of William James in the late 19th century, and Alfred Adler and Sigmund Freud in the 20th, enriched by the contributions of later personality and role theorists. The self is defined as the unique organization of each person; a style is the self in action. Different life styles and their components are expressed in different situations. I posit that humor and positive thinking, combined with meaning and purpose, are vital components of all constructive life styles. The knowledge of life styles cuts through diagnostic labels to reveal our universal humanity. It can be fruitfully applied to patients and nonpatients alike and, I found, for the self-understanding of therapist. The clinical application of life styles is illustrated through numerous vignettes.
Effect of grinding on the fatigue life of titanium alloy (5 Al-2.5 Sn) under dry and wet conditions
NASA Technical Reports Server (NTRS)
Rangaswamy, Partha; Terutung, Hendra; Jeelani, Shaik
1989-01-01
The principal factors in the performance of aerospace materials are strength-to-weight ratio, fatigue life, fracture toughness, survivability and, of course, reliability. Machining processes and, in particular, grinding under adverse conditions have been found to cause damage to surface integrity and affect the residual stress distribution in the surface and subsurface region. These effects have a direct bearing on the fatigue life. In this investigation the effects of grinding conditions on the fatigue life of Titanium 5 Al-2.5Sn were studied. This alloy is used in ground form in the manufacturing of some critical components in the space shuttle's main engine. It is essential that materials for such applications be properly characterized for use in severe service conditions. Flat sub-size specimens 0.1 inch thick were ground on a surface grinding machine equipped with a variable speed motor at speeds of 2000 to 6000 rpm using SiC wheels of grit sizes 60 and 120. The grinding parameters used in this investigation were chosen from a separate study. The ground specimens were then fatigued at a selected stress and the resulting lives were compared with that of the virgin material. The surfaces of the specimens were examined under a scanning electron microscope, and the roughness and hardness were measured using a standard profilometer and microhardness tester, respectively. The fatigue life of the ground specimens was found to decrease with the increase in speed for both dry and wet conditions. The fatigue life of specimens ground under wet conditions showed a significant increase at the wheel speed of 2000 rpm for both the grit sizes and thereafter decreased with increase profilometry, microhardness measurements and scanning electron microscopic examination.
Effects of anxiety and depression in patients with gastroesophageal reflux disease.
Kessing, Boudewijn F; Bredenoord, Albert J; Saleh, Caroline M G; Smout, André J P M
2015-06-01
Increased levels of anxiety and depression have been associated with esophageal hyperalgesia and an increased risk of gastroesophageal reflux disease (GERD). We investigated the effects of anxiety and depression on GERD symptoms and the perception of reflux episodes in a well-characterized group of patients. We performed a prospective study of 225 consecutive patients who had symptoms of GERD evaluated. Patients underwent ambulatory 24-hour pH impedance monitoring, and levels of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale. GERD was diagnosed in 147 patients (78 patients had functional heartburn); 36 patients were hypersensitive to gastroesophageal reflux. Among patients with GERD, increased levels of anxiety were associated with more severe retrosternal pain and retrosternal burning. Furthermore, increased levels of anxiety and depression each were associated with lower scores of the mental component of quality of life questionnaire. Levels of anxiety or depression were not associated with the number of reflux symptoms reported during 24-hour pH impedance monitoring or with the number of symptoms associated with a reflux event. Among GERD patients with hypersensitivity to reflux, levels of anxiety and depression and decreases in quality of life were similar to those of other patients with GERD. Patients with functional heartburn had higher levels of anxiety than patients with GERD. In patients with GERD, increased levels of anxiety are associated with increased severity of retrosternal pain and heartburn and reduced quality of life. Patients with GERD with hypersensitivity to gastroesophageal reflux have similar levels of anxiety and similar quality-of-life scores as other patients with GERD. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.
Effects of Increased Flight on the Energetics and Life History of the Butterfly Speyeria mormonia
Niitepõld, Kristjan; Boggs, Carol L.
2015-01-01
Movement uses resources that may otherwise be allocated to somatic maintenance or reproduction. How does increased energy expenditure affect resource allocation? Using the butterfly Speyeria mormonia, we tested whether experimentally increased flight affects fecundity, lifespan or flight capacity. We measured body mass (storage), resting metabolic rate and lifespan (repair and maintenance), flight metabolic rate (flight capacity), egg number and composition (reproduction), and food intake across the adult lifespan. The flight treatment did not affect body mass or lifespan. Food intake increased sufficiently to offset the increased energy expenditure. Total egg number did not change, but flown females had higher early-life fecundity and higher egg dry mass than control females. Egg dry mass decreased with age in both treatments. Egg protein, triglyceride or glycogen content did not change with flight or age, but some components tracked egg dry mass. Flight elevated resting metabolic rate, indicating increased maintenance costs. Flight metabolism decreased with age, with a steeper slope for flown females. This may reflect accelerated metabolic senescence from detrimental effects of flight. These effects of a drawdown of nutrients via flight contrast with studies restricting adult nutrient input. There, fecundity was reduced, but flight capacity and lifespan were unchanged. The current study showed that when food resources were abundant, wing-monomorphic butterflies living in a continuous meadow landscape resisted flight-induced stress, exhibiting no evidence of a flight-fecundity or flight-longevity trade-off. Instead, flight changed the dynamics of energy use and reproduction as butterflies adopted a faster lifestyle in early life. High investment in early reproduction may have positive fitness effects in the wild, as long as food is available. Our results help to predict the effect of stressful conditions on the life history of insects living in a changing world. PMID:26510164
Mao, Zhongping Lily; Modi, Nishit B
2016-08-01
Parkinson disease is an age-related disorder of the central nervous system principally due to loss of dopamine-producing cells in the midbrain. Levodopa, in combination with carbidopa, is widely regarded as an effective treatment for the symptoms of Parkinson disease. A dose-response relationship is established for carbidopa-levodopa extended-release capsules (IPX066) in levodopa-naive Parkinson disease patients using a disease progression model. Unified Parkinson Disease Rating Scale (UPDRS) part II plus part III scores from 171 North American patients treated with placebo or IPX066 for approximately 30 weeks from a double-blind, parallel-group, dose-ranging study were used to develop the pharmacodynamic model. The model comprised 3 components: a linear function describing disease progression, a component describing placebo (or nonlevodopa) effects, and a component to describe the effect of levodopa. Natural disease progression in early Parkinson disease as measured by UPDRS was 11.6 units/year and faster in patients with more severe disease (Hoehn-Yahr stage 3). Maximum placebo/nonlevodopa response was 23.0% of baseline UPDRS. Maximum levodopa effect from IPX066 was 76.7% of baseline UPDRS, and the ED50 was 450 mg levodopa. Equilibration half-life for the effect compartment was 62.8 days. Increasing age increased and being female decreased equilibration half-life. The quantitative model allowed description of the entire time course of response to clinical trial intervention. © 2016, The Authors. The Journal of Clinical Pharmacology Published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.
Empathy-Related Responding in Chinese Toddlers: Factorial Structure and Cognitive Contributors
ERIC Educational Resources Information Center
Huang, Heqing; Su, Yanjie; Jin, Jian
2017-01-01
The critical role of the second year of life in the development of empathy is well accepted by psychologists. However, the developmental trends of the different components of empathy and the potential factors underlying these components during this critical period remain unclear. Eighty-four Chinese toddlers in the second year of life participated…
The Components of Communication Systems in Universities: Their Influence on Academic Work Life
ERIC Educational Resources Information Center
Uslu, Baris
2018-01-01
This research aimed to identify the components of communication systems in universities and to explore their influence on academic life. To collect data, interviews were carried out with academics from Australian universities. Thematic descriptive and content analyses were performed on the data-set. Analyses showed that the human relations unit,…
NASA Astrophysics Data System (ADS)
Wu, C. W.; Liu, B.; Wei, M. Y.; Liu, L. F.
2017-05-01
Proton exchange membrane fuel cell (PEMFC) stack usually undergoes various vibrations during packing, transportation and serving time, in particular for those used in the automobiles and portable equipment. Based on the Miner fatigue damage theory, the fatigue lives of the fuel cell components are first assessed. Then the component fatigue life contours of the stack are obtained under four working conditions, i.e. the three single-axial (in X-, Y- and Z-axis separately) and multi-axial random vibrations. Accordingly, the component damage under various vibrations is evaluated. The stress distribution on the gasket and PEM will greatly affect their fatigue lives. Finally, we compare the fatigue lives of 4-bolt- and 6-bolt-clamping stacks under the same total clamping force, and find that increasing the bolt number could improve the bolt fatigue lives.
An adaptive data-driven method for accurate prediction of remaining useful life of rolling bearings
NASA Astrophysics Data System (ADS)
Peng, Yanfeng; Cheng, Junsheng; Liu, Yanfei; Li, Xuejun; Peng, Zhihua
2018-06-01
A novel data-driven method based on Gaussian mixture model (GMM) and distance evaluation technique (DET) is proposed to predict the remaining useful life (RUL) of rolling bearings. The data sets are clustered by GMM to divide all data sets into several health states adaptively and reasonably. The number of clusters is determined by the minimum description length principle. Thus, either the health state of the data sets or the number of the states is obtained automatically. Meanwhile, the abnormal data sets can be recognized during the clustering process and removed from the training data sets. After obtaining the health states, appropriate features are selected by DET for increasing the classification and prediction accuracy. In the prediction process, each vibration signal is decomposed into several components by empirical mode decomposition. Some common statistical parameters of the components are calculated first and then the features are clustered using GMM to divide the data sets into several health states and remove the abnormal data sets. Thereafter, appropriate statistical parameters of the generated components are selected using DET. Finally, least squares support vector machine is utilized to predict the RUL of rolling bearings. Experimental results indicate that the proposed method reliably predicts the RUL of rolling bearings.
NASA Astrophysics Data System (ADS)
Sahlan, Muhamad; Raihani Rahman, Mohammad
2017-07-01
One of many applications of essential oils is as fragrance in perfumery. Menthol, benzyl acetate, and vanillin, each represents olfactive characteristic of peppermint leaves, jasmine flowers, and vanilla beans, are commonly used in perfumery. These components are highly volatile, hence the fragrance components will quickly evaporate resulting in short-lasting scent and low shelf life. In this research, said components have been successfully encapsulated simultaneously inside Polyvinyl Alcohol (PVA) using simple coacervation method to increase its shelf life. Optimization has been done using Central Composite Diagram with 4 independent variables, i.e. composition of menthol, benzyl acetate, vanillin, and tergitol 15-S-9 (as emulsifier). Encapsulation efficiency, loading capacity, and microcapsule size have been measured. In optimized composition of menthol (13.98 %w/w), benzyl acetate (14.75 %w/w), vanillin (17.84 %w/w), and tergitol 15-S-9 (13.4 %w/w) encapsulation efficiency of 97,34% and loading capacity of 46,46% have been achieved. Mean diameter of microcapsule is 20,24 μm and within range of 2,011-36,24 μm. Final product was achieved in the form of cross linked polyvinyl alcohol with hydrogel consistency and orange to yellow in color.
Environmental Barrier Coatings for Ceramic Matrix Composites - An Overview
NASA Technical Reports Server (NTRS)
Lee, Kang; van Roode, Mark; Kashyap, Tania; Zhu, Dongming; Wiesner, Valerie
2017-01-01
SiC/SiC Ceramic Matrix Composites (CMCs) are increasingly being considered as structural materials for advanced power generation equipment because of their light weight, higher temperature capability, and oxidation resistance. Limitations of SiC/SiC CMCs include surface recession and component cracking and associated chemical changes in the CMC. The solutions pursued to improve the life of SiC/SiC CMCs include the incorporation of coating systems that provide surface protection, which has become known as an Environmental Barrier Coating (EBC). The development of EBCs for the protection of gas turbine hot section CMC components was a continuation of coating development work for corrosion protection of silicon-based monolithics. Work on EBC development for SiC/SiC CMCs has been ongoing at several national laboratories and the original gas turbine equipment manufacturers. The work includes extensive laboratory, rig and engine testing, including testing of EBC coated SiC/SiC CMCs in actual field applications. Another EBC degradation issue which is especially critical for CMC components used in aircraft engines is the degradation from glassy deposits of calcium-magnesium-aluminosilicate (CMAS) with other minor oxides. This paper addresses the need for and properties of external coatings on SiC/SiC CMCs to extend their useful life in service and the retention of their properties.
Diabetes burden in Brazil: fraction attributable to overweight, obesity, and excess weight
Flor, Luísa Sorio; Campos, Monica Rodrigues; de Oliveira, Andreia Ferreira; Schramm, Joyce Mendes de Andrade
2015-01-01
OBJECTIVE To estimate the burden of type 2 diabetes mellitus and its percentage attributable to overweight and obesity in Brazil. METHODS The burden of diabetes mellitus was described in terms of disability-adjusted life years, which is the sum of two components: years of life lost and years lived with disability. To calculate the fraction of diabetes mellitus attributable to overweight, obesity, and excess weight, we used the prevalence of these risk factors according to sex and age groups (> 20 years) obtained from the 2008 Pesquisa Dimensões Sociais das Desigualdades (Social Dimensions of Inequality Survey) and the relative risks derived from the international literature. RESULTS Diabetes mellitus accounted for 5.4% of Brazilian disability-adjusted life years in 2008, with the largest fraction attributed to the morbidity component (years lived with disability). Women exhibited higher values for disability-adjusted life years. In Brazil, 49.2%, 58.3%, and 70.6% of diabetes mellitus in women was attributable to overweight, obesity, and excess weight, respectively. Among men, these percentages were 40.5%, 45.4%, and 60.3%, respectively. Differences were observed with respect to Brazilian regions and age groups. CONCLUSIONS A large fraction of diabetes mellitus was attributable to preventable individual risk factors and, in about six years, the contribution of these factors significant increased, particularly among men. Policies aimed at promoting healthy lifestyle habits, such as a balanced diet and physical activity, can have a significant impact on reducing the burden of diabetes mellitus in Brazil. PMID:26018787
Diabetes burden in Brazil: fraction attributable to overweight, obesity, and excess weight.
Flor, Luísa Sorio; Campos, Monica Rodrigues; Oliveira, Andreia Ferreira de; Schramm, Joyce Mendes de Andrade
2015-01-01
OBJECTIVE To estimate the burden of type 2 diabetes mellitus and its percentage attributable to overweight and obesity in Brazil. METHODS The burden of diabetes mellitus was described in terms of disability-adjusted life years, which is the sum of two components: years of life lost and years lived with disability. To calculate the fraction of diabetes mellitus attributable to overweight, obesity, and excess weight, we used the prevalence of these risk factors according to sex and age groups (> 20 years) obtained from the 2008 Pesquisa Dimensões Sociais das Desigualdades (Social Dimensions of Inequality Survey) and the relative risks derived from the international literature. RESULTS Diabetes mellitus accounted for 5.4% of Brazilian disability-adjusted life years in 2008, with the largest fraction attributed to the morbidity component (years lived with disability). Women exhibited higher values for disability-adjusted life years. In Brazil, 49.2%, 58.3%, and 70.6% of diabetes mellitus in women was attributable to overweight, obesity, and excess weight, respectively. Among men, these percentages were 40.5%, 45.4%, and 60.3%, respectively. Differences were observed with respect to Brazilian regions and age groups. CONCLUSIONS A large fraction of diabetes mellitus was attributable to preventable individual risk factors and, in about six years, the contribution of these factors significant increased, particularly among men. Policies aimed at promoting healthy lifestyle habits, such as a balanced diet and physical activity, can have a significant impact on reducing the burden of diabetes mellitus in Brazil.
Evans, Simon R; Gustafsson, Lars; Sheldon, Ben C
2011-06-01
Sexual ornaments are predicted to honestly signal individual condition. We might therefore expect ornament expression to show a senescent decline, in parallel with late-life deterioration of other characters. Conversely, life-history theory predicts the reduced residual reproductive value of older individuals will favor increased investment in sexually attractive traits. Using a 25-year dataset of more than 5000 records of breeding collared flycatchers (Ficedula albicollis) of known age, we quantify cross-sectional patterns of age-dependence in ornamental plumage traits and report long-term declines in expression that mask highly significant positive age-dependency. We partition this population-level age-dependency into its between- and within-individual components and show expression of ornamental white plumage patches exhibits within-individual increases with age in both sexes, consistent with life-history theory. For males, ornament expression also covaries with life span, such that, within a cohort, ornamentation indicates survival. Finally, we compared longitudinal age-dependency of reproductive traits and ornamental traits in both sexes, to assess whether these two trait types exhibit similar age-dependency. These analyses revealed contrasting patterns: reproductive traits showed within-individual declines in late-life females consistent with senescence; ornamental traits showed the opposite pattern in both males and females. Hence, our results for both sexes suggest that age-dependent ornament expression is consistent with life-history models of optimal signaling and, unlike reproductive traits, proof against senescence. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Winters, Brian R; Wright, Jonathan L; Holt, Sarah K; Dash, Atreya; Gore, John L; Schade, George R
2017-09-05
Health related quality of life after radical cystectomy and ileal conduit is not well quantified at the population level. We evaluated health related quality of life in patients with bladder cancer compared with noncancer controls and patients with colorectal cancer using data from SEER (Surveillance, Epidemiology and End Results)-MHOS (Medicare Health Outcomes Survey). SEER-MHOS data from 1998 to 2013 were used to identify patients with bladder cancer and those with colorectal cancer who underwent extirpative surgery with ileal conduit or colostomy creation, respectively. A total of 166 patients with bladder cancer treated with radical cystectomy were propensity matched 1:5 to 830 noncancer controls and compared with 154 patients with colorectal cancer. Differences in Mental and Physical Component Summary scores as well as component subscores were determined between patients with bladder cancer, patients with colorectal cancer and noncancer controls. SEER-MHOS patients were more commonly male and white with a mean ± SD age of 77 ± 6 years. Patients treated with radical cystectomy had significantly lower Physical Component Summary scores, select physical subscale scores and all mental subscale scores compared with noncancer controls. These findings were similar in the subset of 40 patients treated with radical cystectomy who had available preoperative and postoperative survey data. Global Mental Component Summary scores did not differ significantly between the groups. No significant differences were observed in global Mental Component Summary, Physical Component Summary or subscale scores between patients with bladder cancer and patients with colorectal cancer. Patients with bladder cancer who undergo radical cystectomy have significant declines in multiple components of physical and mental health related quality of life vs noncancer controls, which mirror those of patients with colorectal cancer. Further longitudinal study is required to better codify the effectors of poor health related quality of life after radical cystectomy to improve patient expectations and outcomes. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Yanosy, J. L.; Rowell, L. F.
1985-01-01
Efforts to make increasingly use of suitable computer programs in the design of hardware have the potential to reduce expenditures. In this context, NASA has evaluated the benefits provided by software tools through an application to the Environmental Control and Life Support (ECLS) system. The present paper is concerned with the benefits obtained by an employment of simulation tools in the case of the Air Revitalization System (ARS) of a Space Station life support system. Attention is given to the ARS functions and components, a computer program overview, a SAND (solid amine water desorbed) bed model description, a model validation, and details regarding the simulation benefits.
Reminiscence in dementia: a concept analysis.
Dempsey, Laura; Murphy, Kathy; Cooney, Adeline; Casey, Dympna; O'Shea, Eamon; Devane, Declan; Jordan, Fionnuala; Hunter, Andrew
2014-03-01
This paper is a report of an analysis of the concept of reminiscence in dementia and highlights its uses as a therapeutic intervention used on individuals with dementia. No single definition of reminiscence exists in healthcare literature; however, definitions offered have similar components. The term life review is commonly used when discussing reminiscence; however, both terms are quite different in their goals, theory base and content. This concept analysis identified reminiscence as a process which occurs in stages, involving the recalling of early life events and interaction between individuals. The antecedents of reminiscence are age, life transitions, attention span, ability to recall, ability to vocalise and stressful situations. Reminiscence can lead to positive mental health, enhanced self esteem and improved communication skills. It also facilitates preparation for death, increases interaction between people, prepares for the future and evaluates a past life. Reminiscence therapy is used extensively in dementia care and evidence shows when used effectively it helps individuals retain a sense of self worth, identity and individuality.
Ceramic Matrix Composites (CMC) Life Prediction Method Development
NASA Technical Reports Server (NTRS)
Levine, Stanley R.; Calomino, Anthony M.; Ellis, John R.; Halbig, Michael C.; Mital, Subodh K.; Murthy, Pappu L.; Opila, Elizabeth J.; Thomas, David J.; Thomas-Ogbuji, Linus U.; Verrilli, Michael J.
2000-01-01
Advanced launch systems (e.g., Reusable Launch Vehicle and other Shuttle Class concepts, Rocket-Based Combine Cycle, etc.), and interplanetary vehicles will very likely incorporate fiber reinforced ceramic matrix composites (CMC) in critical propulsion components. The use of CMC is highly desirable to save weight, to improve reuse capability, and to increase performance. CMC candidate applications are mission and cycle dependent and may include turbopump rotors, housings, combustors, nozzle injectors, exit cones or ramps, and throats. For reusable and single mission uses, accurate prediction of life is critical to mission success. The tools to accomplish life prediction are very immature and not oriented toward the behavior of carbon fiber reinforced silicon carbide (C/SiC), the primary system of interest for a variety of space propulsion applications. This paper describes an approach to satisfy the need to develop an integrated life prediction system for CMC that addresses mechanical durability due to cyclic and steady thermomechanical loads, and takes into account the impact of environmental degradation.
Vickers, M. H.; Sloboda, D. M.
2012-01-01
Obesity and the metabolic syndrome have reached epidemic proportions worldwide with far-reaching health care and economic implications. The rapid increase in the prevalence of these disorders suggests that environmental and behavioral influences, rather than genetic causes, are fueling the epidemic. The developmental origins of health and disease hypothesis has highlighted the link between the periconceptual, fetal, and early infant phases of life and the subsequent development of metabolic disorders in later life. In particular, the impact of poor maternal nutrition on susceptibility to later life metabolic disease in offspring is now well documented. Several studies have now shown, at least in experimental animal models, that some components of the metabolic syndrome, induced as a consequence of developmental programming, are potentially reversible by nutritional or targeted therapeutic interventions during windows of developmental plasticity. This review will focus on critical windows of development and possible therapeutic avenues that may reduce metabolic and obesogenic risk following an adverse early life environment. PMID:22783205
Thermal barrier coating life prediction model development
NASA Technical Reports Server (NTRS)
Sheffler, K. D.; Demasi, J. T.
1985-01-01
A methodology was established to predict thermal barrier coating life in an environment simulative of that experienced by gas turbine airfoils. Specifically, work is being conducted to determine failure modes of thermal barrier coatings in the aircraft engine environment. Analytical studies coupled with appropriate physical and mechanical property determinations are being employed to derive coating life prediction model(s) on the important failure mode(s). An initial review of experimental and flight service components indicates that the predominant mode of TBC failure involves thermomechanical spallation of the ceramic coating layer. This ceramic spallation involves the formation of a dominant crack in the ceramic coating parallel to and closely adjacent to the metal-ceramic interface. Initial results from a laboratory test program designed to study the influence of various driving forces such as temperature, thermal cycle frequency, environment, and coating thickness, on ceramic coating spalling life suggest that bond coat oxidation damage at the metal-ceramic interface contributes significantly to thermomechanical cracking in the ceramic layer. Low cycle rate furnace testing in air and in argon clearly shows a dramatic increase of spalling life in the non-oxidizing environments.
Planning for Cost Effectiveness.
ERIC Educational Resources Information Center
Schlaebitz, William D.
1984-01-01
A heat pump life-cycle cost analysis is used to explain the technique. Items suggested for the life-cycle analysis approach include lighting, longer-life batteries, site maintenance, and retaining experts to inspect specific building components. (MLF)
Prediction of life stress on athletes' burnout: the dual role of perceived stress.
Chyi, Theresa; Lu, Frank Jing-Horng; Wang, Erica T W; Hsu, Ya-Wen; Chang, Ko-Hsin
2018-01-01
Although many studies adopted Smith's (1986) cognitive-affective model of athletic burnout in examining stress-burnout relationship, very few studies examined the mediating/moderating role of perceived stress on the stress-burnout relationship. We sampled 195 college student-athletes and assessed their life stress, perceived stress, and burnout. Correlation analyses found all study variables correlated. Two separate hierarchical regression analyses found that the "distress" component of perceived stress mediated athletes' two types of life stress-burnout relationship but "counter-stress" component of perceived stress-moderated athletes' general-life stress-burnout relationship. We concluded that interweaving relationships among athletes' life stress, perceived stress, and burnout are not straightforward. Future research should consider the nature of athletes life stress, and dual role of perceived stress in examining its' association with related psychological responses in athletic settings.
Extended Performance 8-cm Mercury Ion Thruster
NASA Technical Reports Server (NTRS)
Mantenieks, M. A.
1981-01-01
A slightly modified 8-cm Hg ion thruster demonstrated significant increase in performance. Thrust was increased by almost a factor of five over that of the baseline thruster. Thruster operation with various three grid ion optics configurations; thruster performance as a function of accelerator grid open area, cathode baffle, and cathode orifice size; and a life test of 614 hours at a beam current of 250 mA (17.5 mN thrust) are discussed. Highest thruster efficiency was obtained with the smallest open area accelerator grid. The benefits in efficiency from the low neutral loss grids were mitigated, however, by the limitation such grids place on attainable ion beam current densities. The thruster components suffered negligible weight losses during a life test, which indicated that operation of the 8-cm thruster at extended levels of thrust and power is possible with no significant loss of lifetime.
[Impact of ECMO on drugs pharmacokinetics].
Hasni, Nesrine; Lemaitre, Florian; Fernandez, Christine; Combes, Alain; Farinotti, Robert
2011-01-01
Extracorporeal membrane oxygenation (ECMO) is a life support system used in the treatment of patients of all ages with severe respiratory or cardiorespiratory failure. Despite the intensive use of drugs in the treatment of patients on ECMO, few studies have been conducted to determine the impact of this device on the pharmacokinetics of drugs. Publications in this field have shown pharmacokinetics changes resulting in an increase in volume of distribution of drugs and/or decreased clearance with consequent increase of their half-life. Reduced plasma concentrations of some drugs due to their adsorption on the different components of the circuit further complicates the determination of pharmacokinetic parameters of patients treated by ECMO. The literature published up to now on the pharmacokinetic changes associated with ECMO provide preliminary support for dosage adjustment. However, more research is needed to identify dosage strategies for this patient population. © 2011 Société Française de Pharmacologie et de Thérapeutique.
32 CFR Appendix to Part 162 - Reporting Procedures
Code of Federal Regulations, 2014 CFR
2014-07-01
... generated. e. Projected Life-Cycle Savings. For each PIF project provide the estimated amount of savings the project is projected to earn over the project's economic life. f. Projected Life-Cycle Cost Avoidance. For... Projected Life-Cycle Savings. e. Total Projected Life-Cycle Cost Avoidance. 3. CSI. Each DoD Component that...
Turbine Engine Clearance Control Systems: Current Practices and Future Directions
NASA Astrophysics Data System (ADS)
Lattime, Scott B.; Steinetz, Bruce M.
2002-09-01
Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed 1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.
Turbine Engine Clearance Control Systems: Current Practices and Future Directions
NASA Technical Reports Server (NTRS)
Lattime, Scott B.; Steinetz, Bruce M.
2002-01-01
Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.
LIFE CYCLE ASSESSMENT FOR PC BLEND 2 AIRCRAFT RADOME DEPAINTER
This report describes the life cycle assessment on a potential replacement solvent blend for aircraft radome depainting at the Oklahoma City Air Logistics Center at Tinker Air Force Base. The life cycle assessment is composed of three separate but interrelated components: life cy...
NASA Technical Reports Server (NTRS)
Quentmeyer, R. J.; Mcdonald, G.; Hendricks, R. C.
1985-01-01
Components fabricated of, or coated with, ceramics have lower parasitic cooling requirements. Techniques are discussed for fabricating thin-shell ceramic components and ceramic coatings for applications in rocket or jet engine environments. Thin ceramic shells with complex geometric forms involving convolutions and reentrant surfaces were fabricated by mandrel removal. Mandrel removal was combined with electroplating or plasma spraying and isostatic pressing to form a metal support for the ceramic. Rocket engine thrust chambers coated with 0.08 mm (3 mil) of ZrO2-8Y2O3 had no failures and a tenfold increase in engine life. Some measured mechanical properties of the plasma-sprayed ceramic are presented.
Bartels, Meike
2015-03-01
Wellbeing is a major topic of research across several disciplines, reflecting the increasing recognition of its strong value across major domains in life. Previous twin-family studies have revealed that individual differences in wellbeing are accounted for by both genetic as well as environmental factors. A systematic literature search identified 30 twin-family studies on wellbeing or a related measure such as satisfaction with life or happiness. Review of these studies showed considerable variation in heritability estimates (ranging from 0 to 64 %), which makes it difficult to draw firm conclusions regarding the genetic influences on wellbeing. For overall wellbeing twelve heritability estimates, from 10 independent studies, were meta-analyzed by computing a sample size weighted average heritability. Ten heritability estimates, derived from 9 independent samples, were used for the meta-analysis of satisfaction with life. The weighted average heritability of wellbeing, based on a sample size of 55,974 individuals, was 36 % (34-38), while the weighted average heritability for satisfaction with life was 32 % (29-35) (n = 47,750). With this result a more robust estimate of the relative influence of genetic effects on wellbeing is provided.
Controls and Health Management Technologies for Intelligent Aerospace Propulsion Systems
NASA Technical Reports Server (NTRS)
Garg, Sanjay
2004-01-01
With the increased emphasis on aircraft safety, enhanced performance and affordability, and the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Technology Branch at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC) in Cleveland, Ohio, is leading and participating in various projects in partnership with other organizations within GRC and across NASA, the U.S. aerospace industry, and academia to develop advanced controls and health management technologies that will help meet these challenges through the concept of an Intelligent Engine. The key enabling technologies for an Intelligent Engine are the increased efficiencies of components through active control, advanced diagnostics and prognostics integrated with intelligent engine control to enhance component life, and distributed control with smart sensors and actuators in an adaptive fault tolerant architecture. This paper describes the current activities of the Controls and Dynamics Technology Branch in the areas of active component control and propulsion system intelligent control, and presents some recent analytical and experimental results in these areas.
Introduction to Advanced Engine Control Concepts
NASA Technical Reports Server (NTRS)
Sanjay, Garg
2007-01-01
With the increased emphasis on aircraft safety, enhanced performance and affordability, and the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch at NASA (National Aeronautics and Space Administration) Glenn Research Center (GRC) in Cleveland, Ohio, is leading and participating in various projects in partnership with other organizations within GRC and across NASA, the U.S. aerospace industry, and academia to develop advanced controls and health management technologies that will help meet these challenges through the concept of Intelligent Propulsion Systems. The key enabling technologies for an Intelligent Propulsion System are the increased efficiencies of components through active control, advanced diagnostics and prognostics integrated with intelligent engine control to enhance operational reliability and component life, and distributed control with smart sensors and actuators in an adaptive fault tolerant architecture. This presentation describes the current activities of the Controls and Dynamics Branch in the areas of active component control and propulsion system intelligent control, and presents some recent analytical and experimental results in these areas.
A real time neural net estimator of fatigue life
NASA Technical Reports Server (NTRS)
Troudet, T.; Merrill, W.
1990-01-01
A neural network architecture is proposed to estimate, in real-time, the fatigue life of mechanical components, as part of the intelligent Control System for Reusable Rocket Engines. Arbitrary component loading values were used as input to train a two hidden-layer feedforward neural net to estimate component fatigue damage. The ability of the net to learn, based on a local strain approach, the mapping between load sequence and fatigue damage has been demonstrated for a uniaxial specimen. Because of its demonstrated performance, the neural computation may be extended to complex cases where the loads are biaxial or triaxial, and the geometry of the component is complex (e.g., turbopumps blades). The generality of the approach is such that load/damage mappings can be directly extracted from experimental data without requiring any knowledge of the stress/strain profile of the component. In addition, the parallel network architecture allows real-time life calculations even for high-frequency vibrations. Owing to its distributed nature, the neural implementation will be robust and reliable, enabling its use in hostile environments such as rocket engines.
Work stress and reduced health in young physicians: prospective evidence from Swiss residents.
Buddeberg-Fischer, Barbara; Klaghofer, Richard; Stamm, Martina; Siegrist, Johannes; Buddeberg, Claus
2008-10-01
Job stress, investigated by the effort-reward model in various working environments in different countries, has been widely reported, yet studies addressing physicians are lacking. The present study investigated the perceived job stress, its association with the amount of working hours, and its impact on young physicians' self-reported health and their satisfaction with life during residency. In a prospective study design, a cohort of Swiss medical school graduates was followed up, beginning in 2001. In their second and fourth years of residency, 433 physicians assessed their effort-reward imbalance, overcommitment, physical and mental well-being and satisfaction in life. Taking the longitudinal design into account, four categories of stressed residents were defined: (1) subjects not reporting high work stress at either measurement, (2) subjects reporting high work stress in the second but not in the fourth year of residency, (3) subjects with onset of high work stress in fourth year and (4) residents reporting high work stress at both measurements. All components of the perceived stress at work were significantly correlated with the amount of working hours, effort showing the highest correlation. While two-thirds of the participants do not report high work stress, assessed by the extrinsic part of the effort-reward imbalance model (the ratio between effort and reward) and 12% show a decrease of stress over time, there are 15% with an increase of stress over time, and 10% with persistently high stress experience. In terms of the intrinsic stress component (overcommitment), 71% show low values, 12% show a decrease, 9% an increase and 8% constantly high values. The groups with constant and increasing extrinsic and intrinsic stress experience exhibit significantly worse health and life satisfaction compared to the remaining groups, after controlling for gender and baseline health. Stress at work in young physicians, especially when being experienced over a longer period in postgraduate training, has to be a matter of concern because of its negative impact on health and life satisfaction and the risk of developing symptoms of burnout in the long run.
Stress Analysis of B-52B and B-52H Air-Launching Systems Failure-Critical Structural Components
NASA Technical Reports Server (NTRS)
Ko, William L.
2005-01-01
The operational life analysis of any airborne failure-critical structural component requires the stress-load equation, which relates the applied load to the maximum tangential tensile stress at the critical stress point. The failure-critical structural components identified are the B-52B Pegasus pylon adapter shackles, B-52B Pegasus pylon hooks, B-52H airplane pylon hooks, B-52H airplane front fittings, B-52H airplane rear pylon fitting, and the B-52H airplane pylon lower sway brace. Finite-element stress analysis was performed on the said structural components, and the critical stress point was located and the stress-load equation was established for each failure-critical structural component. The ultimate load, yield load, and proof load needed for operational life analysis were established for each failure-critical structural component.
Brain responses to tonal changes in the first two years of life
Jing, Hongkui; Benasich, April A.
2007-01-01
Maturation of auditory perceptual and discrimination process within the first two years of life is investigated in healthy infants by examining event-related potentials (ERPs). High-density EEG signals were recorded from the scalp monthly between 3 and 24 months of age. Two types of stimuli (100 vs. 100 Hz for standard stimuli; 100 vs. 300 Hz for deviant stimuli; occurrence rate: 85:15%) were presented using an oddball paradigm. Latencies and amplitudes were compared across development. The results showed that latencies of P150, N250, P350, and N450 components gradually decreased with increasing age. Amplitudes of the N250 and P350 components gradually increased and reached the maximum at 9 months, and then gradually decreased with the increase of age. Mismatch negativity was not obvious at 3 months of age, but was seen at 4–5 months and became robust after 6 months. Robust late positivity was recorded at all ages. These mismatch responses were noticeable in the frontal, central, and parietal areas, and the maximal MMN amplitude distribution gradually moved from the parietal area to the frontal area across the age range. Two important periods—one around 6 months and the other around 9 months are suggested in the maturation of auditory central system. Dynamical changes in the underlying source strengths and orientations may be principal contributors to ERP morphological changes in infants within the first 24 months. PMID:16373083
Benchmark Tests for Stirling Convertor Heater Head Life Assessment Conducted
NASA Technical Reports Server (NTRS)
Krause, David L.; Halford, Gary R.; Bowman, Randy R.
2004-01-01
A new in-house test capability has been developed at the NASA Glenn Research Center, where a critical component of the Stirling Radioisotope Generator (SRG) is undergoing extensive testing to aid the development of analytical life prediction methodology and to experimentally aid in verification of the flight-design component's life. The new facility includes two test rigs that are performing creep testing of the SRG heater head pressure vessel test articles at design temperature and with wall stresses ranging from operating level to seven times that (see the following photograph).
NASA Technical Reports Server (NTRS)
Nesbitt, J. A.; Gedwill, M. A.
1984-01-01
Hot-section gas-turbine components typically require some form of coating for oxidation and corrosion protection. Efficient use of coatings requires reliable and accurate predictions of the protective life of the coating. Currently engine inspections and component replacements are often made on a conservative basis. As a result, there is a constant need to improve and develop the life-prediction capability of metallic coatings for use in various service environments. The purpose of this present work is aimed at developing of an improved methodology for predicting metallic coating lives in an oxidizing environment and in a corrosive environment.
Design of biomass management systems and components for closed loop life support systems
NASA Technical Reports Server (NTRS)
1991-01-01
The goal of the EGM 4000/1 Design class was to investigate a Biomass Management System (BMS) and design, fabricate, and test components for biomass management in a closed-loop life support system (CLLSS). The designs explored were to contribute to the development of NASA's Controlled Ecological Life Support System (CELSS) at Kennedy Space Center. Designs included a sectored plant growth unit, a container and transfer mechanism, and an air curtain system for fugitive particle control. The work performed by the class members is summarized.
Safe-life and damage-tolerant design approaches for helicopter structures
NASA Technical Reports Server (NTRS)
Reddick, H. K., Jr.
1983-01-01
The safe-life and damage-tolerant design approaches discussed apply to both metallic and fibrous composite helicopter structures. The application of these design approaches to fibrous composite structures is emphasized. Safe-life and damage-tolerant criteria are applied to all helicopter flight critical components, which are generally categorized as: dynamic components with a main and tail rotor system, which includes blades, hub and rotating controls, and drive train which includes transmission, and main and interconnecting rotor shafts; and the airframe, composed of the fuselage, aerodynamic surfaces, and landing gear.
Sangelaji, Bahram; Smith, Catherin M; Paul, Lorna; Sampath, Kesava Kovanur; Treharne, Gareth J; Hale, Leigh Anne
2016-06-01
A systematic review and meta-analysis was conducted to illustrate whether people with multiple sclerosis engage in more physical activity following behaviour change interventions. MEDLINE, CINAHL, PubMed, Web of Sciences, Cochrane Library, SCOPUS, EMBASE and PEDro were searched from their inception till 30 April 2015. Randomized and clinical controlled trials that used behaviour change interventions to increase physical activity in people with multiple sclerosis were selected, regardless of type or duration of multiple sclerosis or disability severity. Data extraction was conducted by two independent reviewers and the Cochrane Collaboration's recommended method was used to assess the risk of bias of each included study. A total of 19 out of 573 studies were included. Focusing on trials without risk of bias, meta-analysis showed that behaviour change interventions can significantly increase physical activity participation (z = 2.20, p = 0.03, standardised main difference 0.65, 95% confidence interval 0.07 to 1.22, 3 trials, I(2) = 68%) (eight to 12 weeks' duration). Behaviour change interventions did not significantly impact on the physical components of quality of life or fatigue. Behaviour change interventions provided for relatively short duration (eight to 12 weeks) may increase the amount of physical activity people with multiple sclerosis engage in, but appear to have no effect on the physical components of quality of life and fatigue. Further high quality investigations of the efficacy of behaviour change interventions to increase physical activity participation that focus on dose, long-term impact and method of delivery are warranted for people with multiple sclerosis. © The Author(s) 2015.
U.S. Nuclear Weapons Modernization - the Stockpile Life Extension Program
NASA Astrophysics Data System (ADS)
Cook, Donald
2016-03-01
Underground nuclear testing of U.S. nuclear weapons was halted by President George H.W. Bush in 1992 when he announced a moratorium. In 1993, the moratorium was extended by President Bill Clinton and, in 1995, a program of Stockpile Stewardship was put in its place. In 1996, President Clinton signed the Comprehensive Nuclear Test Ban Treaty (CTBT). Twenty years have passed since then. Over the same time, the average age of a nuclear weapon in the stockpile has increased from 6 years (1992) to nearly 29 years (2015). At its inception, achievement of the objectives of the Stockpile Stewardship Program (SSP) appeared possible but very difficult. The cost to design and construct several large facilities for precision experimentation in hydrodynamics and high energy density physics was large. The practical steps needed to move from computational platforms of less than 100 Mflops/sec to 10 Teraflops/sec and beyond were unknown. Today, most of the required facilities for SSP are in place and computational speed has been increased by more than six orders of magnitude. These, and the physicists and engineers in the complex of labs and plants within the National Nuclear Security Administration (NNSA) who put them in place, have been the basis for underpinning an annual decision, made by the weapons lab directors for each of the past 20 years, that resort to underground nuclear testing is not needed for maintaining confidence in the safety and reliability of the U.S stockpile. A key part of that decision has been annual assessment of the physical changes in stockpiled weapons. These weapons, quite simply, are systems that invariably and unstoppably age in the internal weapon environment of radioactive materials and complex interfaces of highly dissimilar organic and inorganic materials. Without an ongoing program to rebuild some components and replace other components to increase safety or security, i.e., life extending these weapons, either underground testing would again be required to assess many changes at once, or confidence in these weapons would be reduced. The strategy and details of the U.S. Stockpile Life Extension Program will be described in this talk. In brief, the strategy is to reduce the number of weapons in the stockpile while increasing confidence in the weapons that remain and, where possible, increase their safety, increase their security, and reduce their nuclear material quantities and yields. A number of ``myths'' pertaining to nuclear weapons, the SSP, and the Stockpile Life Extension Program will be explored.
ERIC Educational Resources Information Center
Campo, Stephanie F.; And Others
1996-01-01
The Quality of Life Index was completed by 120 residential staff for 60 adults with severe to profound mental retardation residing in group homes. Measurement integrity was analyzed through use of principal components analysis, confirmatory rotation of components, and Cronbach alphas. Results are compared with results obtained from a more…
A method of calculating the safe fatigue life of compact, highly-stressed components
NASA Technical Reports Server (NTRS)
Cardick, Arthur W.; Pike, Vera J.
1994-01-01
This paper describes a method which has been developed for estimating the safe fatigue life of compact, highly-stressed and inaccessible components for aeroplanes and helicopters of the Royal Air Force. It is explained why the Design Requirements for British Military Aircraft do not favor the use of a damage-tolerance approach in these circumstances.
Plastic consumption and diet of Glaucous-winged Gulls (Larus glaucescens).
Lindborg, Valerie A; Ledbetter, Julia F; Walat, Jean M; Moffett, Cinamon
2012-11-01
We analyzed dietary habits and presence of plastic in 589 boluses of Glaucous-winged Gulls (Larus glaucescens) as one of two studies on the impact of plastics on marine life in the US Salish Sea. Volunteers dissected boluses collected (2007-2010) from Protection Island, Washington. Components were separated into 23 food and non-food categories. Plastic was found in 12.2% of boluses, with plastic film being the most common plastic form. No diet specialization was observed. Vegetation was the most abundant component, found in 91.3% of boluses. No relationship was observed between any dietary items and occurrence or type of plastic found. Load and potential ecological impact in the marine environment can be expected to increase concurrently with increasing plastic use and number and variety of plastic sources. Future studies are necessary to understand the impacts of plastic ingestion on this species. Copyright © 2012 Elsevier Ltd. All rights reserved.
Life Prediction/Reliability Data of Glass-Ceramic Material Determined for Radome Applications
NASA Technical Reports Server (NTRS)
Choi, Sung R.; Gyekenyesi, John P.
2002-01-01
Brittle materials, ceramics, are candidate materials for a variety of structural applications for a wide range of temperatures. However, the process of slow crack growth, occurring in any loading configuration, limits the service life of structural components. Therefore, it is important to accurately determine the slow crack growth parameters required for component life prediction using an appropriate test methodology. This test methodology also should be useful in determining the influence of component processing and composition variables on the slow crack growth behavior of newly developed or existing materials, thereby allowing the component processing and composition to be tailored and optimized to specific needs. Through the American Society for Testing and Materials (ASTM), the authors recently developed two test methods to determine the life prediction parameters of ceramics. The two test standards, ASTM 1368 for room temperature and ASTM C 1465 for elevated temperatures, were published in the 2001 Annual Book of ASTM Standards, Vol. 15.01. Briefly, the test method employs constant stress-rate (or dynamic fatigue) testing to determine flexural strengths as a function of the applied stress rate. The merit of this test method lies in its simplicity: strengths are measured in a routine manner in flexure at four or more applied stress rates with an appropriate number of test specimens at each applied stress rate. The slow crack growth parameters necessary for life prediction are then determined from a simple relationship between the strength and the applied stress rate. Extensive life prediction testing was conducted at the NASA Glenn Research Center using the developed ASTM C 1368 test method to determine the life prediction parameters of a glass-ceramic material that the Navy will use for radome applications.
Al-Ameri, Mamdoh; Bergman, Per; Franco-Cereceda, Anders; Sartipy, Ulrik
2017-02-01
The aim was to analyze the association between baseline self-reported health-related quality of life and long-term survival after thoracic operations. In a prospective population-based cohort study, we included patients scheduled for thoracic operations and obtained information about preoperative health-related quality of life using the validated quality-of-life instrument Short Form-36. Patients were categorized according to higher or lower physical and mental component scores, compared with an age- and sex-matched reference population. The primary outcome measure was all-cause mortality and was ascertained from Swedish national registers. We used Cox regression for estimation of hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between preoperative physical/mental quality of life and long-term survival while adjusting for differences in baseline characteristics, cancer stage, histopathologic process, and other factors. We included 249 patients between 2006 and 2008. During a median follow-up time of 8.0 years, 119 patients (48%) died. Having a physical component summary score less than reference was significantly associated with mortality (multivariable adjusted HR 2.02, 95% CI: 1.34 to 3.06, p = 0.001). A mental component summary score less than reference was not associated with mortality (adjusted HR 1.32, 95% CI: 0.84 to 3.06, p = 0.233). In patients who underwent thoracic operations, a self-reported physical quality of life lower than reference value was associated with significantly worse survival independent of histopathologic process, cancer stage, extent of operations, and other patient-related factors. The preoperative mental component of quality of life was not associated with long-term survival. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
2014-01-01
Background Musculoskeletal diseases are characterized by a high degree of comorbidity with common mental disorders and are a major cause of health-related exclusion from working life. Using a prospective design we aimed to examine the relative importance of physical and mental health-related quality of life as predictors of disability pension due to musculoskeletal diseases. Methods A subsample (N = 18581) born 1953–1957, participated in the The Hordaland Health Study (HUSK) during 1997–1999, and was followed through December 31st 2004. Baseline measures of health-related quality of life were estimated using the Physical (PCS) and Mental Component Summary (MCS) of the Short Form-12 (SF-12). Further information on education, occupation, smoking, physical activity, number of musculoskeletal pain sites and BMI were provided by questionnaires and health examination. The association between self-perceived physical and mental health and subsequent disability pension, obtained from the national database of health and social benefits was estimated using Cox regression analyses. Results Participants reporting poor physical health (quartile 1) had a marked increased risk for disability pension due to musculoskeletal diseases (age and gender-adjusted hazard ratio = 22.1, 95% CI = 12.5–39.0) compared with those reporting good/somewhat good physical health (quartiles 4 and 3 combined). Adjustment for socioeconomic status and lifestyle factors slightly attenuated the association (hazard ratio = 16.7), and adding number of reported pain sites weakened the association even more (hazard ratio = 7.1, 95% CI = 3.8–12.8). Also, participants reporting poor mental health had a higher risk for disability pension due to musculoskeletal diseases (age and gender adjusted hazard ratio = 1.8, 95% CI = 1.3–2.6); however, in the final model the risk was not statistically significant. Conclusions The physical component in health-related quality of life (SF-12) was a strong predictor of disability pension due to musculoskeletal diseases, whereas the mental component played a less prominent role. PMID:24528674
Haukenes, Inger; Farbu, Erlend H; Riise, Trond; Tell, Grethe S
2014-02-14
Musculoskeletal diseases are characterized by a high degree of comorbidity with common mental disorders and are a major cause of health-related exclusion from working life. Using a prospective design we aimed to examine the relative importance of physical and mental health-related quality of life as predictors of disability pension due to musculoskeletal diseases. A subsample (N = 18,581) born 1953-1957, participated in the The Hordaland Health Study (HUSK) during 1997-1999, and was followed through December 31st 2004. Baseline measures of health-related quality of life were estimated using the Physical (PCS) and Mental Component Summary (MCS) of the Short Form-12 (SF-12). Further information on education, occupation, smoking, physical activity, number of musculoskeletal pain sites and BMI were provided by questionnaires and health examination. The association between self-perceived physical and mental health and subsequent disability pension, obtained from the national database of health and social benefits was estimated using Cox regression analyses. Participants reporting poor physical health (quartile 1) had a marked increased risk for disability pension due to musculoskeletal diseases (age and gender-adjusted hazard ratio = 22.1, 95% CI = 12.5-39.0) compared with those reporting good/somewhat good physical health (quartiles 4 and 3 combined). Adjustment for socioeconomic status and lifestyle factors slightly attenuated the association (hazard ratio = 16.7), and adding number of reported pain sites weakened the association even more (hazard ratio = 7.1, 95% CI = 3.8-12.8). Also, participants reporting poor mental health had a higher risk for disability pension due to musculoskeletal diseases (age and gender adjusted hazard ratio = 1.8, 95% CI = 1.3-2.6); however, in the final model the risk was not statistically significant. The physical component in health-related quality of life (SF-12) was a strong predictor of disability pension due to musculoskeletal diseases, whereas the mental component played a less prominent role.
means of increasing the life of aircraft gas turbine compressor rotor blades and stator vanes . Two proprietary erosion resistant coating systems... engine tests as the two most promising systems for doubling compressor airfoil lives. An Air Force Sponsored program to evaluate the applicability of...Helicopter engine erosion has become a severe problem in S. E. Asia because of extensive operations in sand and dust. Hard coatings offer a potential
Biomaterials in craniofacial reconstruction.
Cho, Younghoon R; Gosain, Arun K
2004-07-01
Biomaterials have become an integral component of craniofacial reconstruction. Their increasing ease of use, long "shelf-life," and safety enables them to be used effectively and play an important role in reducing operating times. There are various biomaterials currently available and specific usages have been characterized well in the literature. This article reviews different biomaterials that can be used in craniofacial reconstruction,including autogenous bone, methyl methacrylate and hard tissue replacement,hydroxyapatite, porous polyethylene, bioactive glass, and demineralized bone.
Processing-Related Issues for the Design and Lifing of SiC/SiC Hot-Section Components
NASA Technical Reports Server (NTRS)
DiCarlo, J.; Bhatt, R.; Morscher, G.; Yun, H. M.
2006-01-01
For successful SiC/SiC engine components, numerous process steps related to the fiber, fiber architecture, interphase coating, and matrix need to be optimized. Under recent NASA-sponsored programs, it was determined that many of these steps in their initial approach were inadequate, resulting in less than optimum thermostructural and life properties for the as-fabricated components. This presentation will briefly review many of these process issues, the key composite properties they degrade, their underlying mechanisms, and current process remedies developed by NASA and others.
Baena-Beato, Pedro Ángel; Artero, Enrique G; Arroyo-Morales, Manuel; Robles-Fuentes, Alejandro; Gatto-Cardia, María Claudia; Delgado-Fernández, Manuel
2014-04-01
To determine the effects of a two-month intensive aquatic therapy programme on back pain, disability, quality of life, body composition and health-related fitness in sedentary adults with chronic low back pain. Controlled clinical trial. Community. Forty-nine sedentary patients with chronic low back pain. Patients were allocated into active group (n = 24, two months, five times/week) or waiting list, control group (n = 25) according to space on the programme. Outcomes variables were pain (visual analogue scale), disability (Oswestry Disability Index), quality of life (Quality Short-Form Health Survey 36), body composition (weight, body mass index, body fat percentage and skeletal muscle mass) and health-related fitness (sit-and-reach, handgrip strength, curl-up, Rockport 1-mile test). The active group significantly improved low back pain (-3.83 ± 0.35 mm on the visual analogue scale ), disability (-12.7 ± 1.3 points for the Oswestry Disability Index) and the standardized physical component (10.3 ± 1.4 points for the Quality Short-Form Health Survey 36) of quality-of-life domains (P < 0.001), with no significant changes on the standardized mental component (P = 0.114). In relation to body composition and fitness, the active group showed significant improvements (all P-values < 0.01). The control group presented no significant change in any parameter. A two-month intensive aquatic therapy programme of high-frequency (five times/week) decreases levels of back pain and disability, increases quality of life, and improves body composition and health-related fitness in sedentary adults with chronic low back pain.
Investigation of safe-life fail-safe criteria for the space shuttle
NASA Technical Reports Server (NTRS)
1972-01-01
An investigation was made to determine the effects of a safe-life design approach and a fail-safe design approach on the space shuttle booster vehicle structure, and to recommend any changes to the structural design criteria. Two configurations of the booster vehicle were considered, one incorporating a delta wing (B-9U configuration) and the other a swept wing (B-16B configuration). Several major structural components of the booster were studied to determine the fatigue life, safe-life, and fail-safe capabilities of the baseline design. Each component was investigated to determine the practicability of applying a safe-life or fail-safe design philosophy, the changes such design approaches might require, and the impact of these changes on weight, cost, development plans, and performance.
[Issues of healthy life style in the professional preparation of the physician].
Kozupitsa, G S
2002-01-01
The main value orientations of medical students are directly or indirectly associated with various components of health. On the other hand, the knowledge of the predominating effect of life style on health, hazards of nicotine and alcohol did not become a persuasion in the majority of students, and high value of health did not transform into motivation forits preservation. That is why special attention in the training of physicians should be paid to the formation of practical habits of fundamentals of healthy life style. Healthy life style, an obligatory component of professional status of a physician, promotes a higher general cognitive activity of students and formation of persuasion of future doctors in their obligatory personal involvement in the solution of the problem of healthy life style of the entire population.
Nurse manager perceptions of role satisfaction and retention at an academic medical center.
Zwink, Jennifer E; Dzialo, Maureen; Fink, Regina M; Oman, Kathleen S; Shiskowsky, Kaycee; Waite, Kathi; DeVine, Deborah; Sanders, Carolyn L; Le-Lazar, Jamie T T
2013-03-01
The aim of this study was to explore the perceptions of inpatient acute care nurse managers (NM) employed at an academic Magnet® hospital about factors that influence NM retention, including current work environment, satisfaction, work-life balance, sucssful NM traits, and personal development and educational needs. Nurse managers are challenged with increased workloads impacting their ability to implement all role components. A qualitative descriptive study design used focus group methodology to explore perceptions of the NM role. Nurse managers identified staff recognition, support, peer relationships, collaboration, and ability to make positive change as factors influencing their decision to remain in the role. Burnout factors included workload issues, work-life imbalance, and difficulty sustaining positive relationships. Traits supporting success were communication, resiliency, integrity, and a visionary outlook. Suggestions for NM development and education were identified. Findings can be used to improve NM satisfaction, work-life balance, recruitment, retention, and succession planning.
NASA Astrophysics Data System (ADS)
Harkness, Linda L.; Sjoberg, Eric S.
1996-06-01
The Georgia Tech Research Institute, sponsored by the Warner Robins Air Logistics Center, has developed an approach for efficiently postulating and evaluating methods for extending the life of radars and other avionics systems. The technique identified specific assemblies for potential replacement and evaluates the system level impact, including performance, reliability and life-cycle cost of each action. The initial impetus for this research was the increasing obsolescence of integrated circuits contained in the AN/APG-63 system. The operational life of military electronics is typically in excess of twenty years, which encompasses several generations of IC technology. GTRI has developed a systems approach to inserting modern technology components into older systems based upon identification of those functions which limit the system's performance or reliability and which are cost drivers. The presentation will discuss the above methodology and a technique for evaluating and ranking the different potential system upgrade options.
Measuring the quality-of-life effects of diagnostic and screening tests.
Swan, J Shannon; Miksad, Rebecca A
2009-08-01
Health-related quality of life (HRQL) is a central concept for understanding the outcomes of medical care. When used in cost-effectiveness analysis, HRQL is typically measured for conditions persisting over long time frames (years), and quality-adjusted life year (QALY) values are generated. Consequently, years are the basic unit of time for cost-effectiveness analysis results: dollars spent per QALY gained. However, shorter term components of health care may also affect HRQL, and there is increased interest in measuring and accounting for these events. In radiology, the short-term HRQL effects of screening and diagnostic testing may affect a test's cost-effectiveness, even though they may only last for days. The unique challenge in radiology HRQL assessment is to realistically tap into the testing and screening experience while remaining consistent with QALY theory. The authors review HRQL assessment and highlight methods developed to specifically address the short-term effects of radiologic screening and testing.
Integration and Assessment of Component Health Prognostics in Supervisory Control Systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ramuhalli, Pradeep; Bonebrake, Christopher A.; Dib, Gerges
Enhanced risk monitors (ERMs) for active components in advanced reactor concepts use predictive estimates of component failure to update, in real time, predictive safety and economic risk metrics. These metrics have been shown to be capable of use in optimizing maintenance scheduling and managing plant maintenance costs. Integrating this information with plant supervisory control systems increases the potential for making control decisions that utilize real-time information on component conditions. Such decision making would limit the possibility of plant operations that increase the likelihood of degrading the functionality of one or more components while maintaining the overall functionality of the plant.more » ERM uses sensor data for providing real-time information about equipment condition for deriving risk monitors. This information is used to estimate the remaining useful life and probability of failure of these components. By combining this information with plant probabilistic risk assessment models, predictive estimates of risk posed by continued plant operation in the presence of detected degradation may be estimated. In this paper, we describe this methodology in greater detail, and discuss its integration with a prototypic software-based plant supervisory control platform. In order to integrate these two technologies and evaluate the integrated system, software to simulate the sensor data was developed, prognostic models for feedwater valves were developed, and several use cases defined. The full paper will describe these use cases, and the results of the initial evaluation.« less
Brown, Jordan; Hanson, Jan E; Schmotzer, Brian; Webel, Allison R
2014-10-01
For people living with HIV (PLWH), spirituality and optimism have a positive influence on their health, can slow HIV disease progression, and can improve quality of life. Our aim was to describe longitudinal changes in spirituality and optimism after participation in the SystemCHANGE™-HIV intervention. Upon completion of the intervention, participants experienced an 11.5 point increase in overall spiritual well-being (p = 0.036), a 6.3 point increase in religious well-being (p = 0.030), a 4.8 point increase in existential well-being (p = 0.125), and a 0.8 point increase in total optimism (p = 0.268) relative to controls. Our data suggest a group-based self-management intervention increases spiritual well-being in PLWH.
Fecundity selection theory: concepts and evidence.
Pincheira-Donoso, Daniel; Hunt, John
2017-02-01
Fitness results from an optimal balance between survival, mating success and fecundity. The interactions between these three components of fitness vary depending on the selective context, from positive covariation between them, to antagonistic pleiotropic relationships when fitness increases in one reduce the fitness of others. Therefore, elucidating the routes through which selection shapes life history and phenotypic adaptations via these fitness components is of primary significance to understanding ecological and evolutionary dynamics. However, while the fitness components mediated by natural (survival) and sexual (mating success) selection have been debated extensively from most possible perspectives, fecundity selection remains considerably less studied. Here, we review the theoretical basis, evidence and implications of fecundity selection as a driver of sex-specific adaptive evolution. Based on accumulating literature on the life-history, phenotypic and ecological aspects of fecundity, we (i) suggest a re-arrangement of the concepts of fecundity, whereby we coin the term 'transient fecundity' to refer to brood size per reproductive episode, while 'annual' and 'lifetime fecundity' should not be used interchangeably with 'transient fecundity' as they represent different life-history parameters; (ii) provide a generalized re-definition of the concept of fecundity selection as a mechanism that encompasses any traits that influence fecundity in any direction (from high to low) and in either sex; (iii) review the (macro)ecological basis of fecundity selection (e.g. ecological pressures that influence predictable spatial variation in fecundity); (iv) suggest that most ecological theories of fecundity selection should be tested in organisms other than birds; (v) argue that the longstanding fecundity selection hypothesis of female-biased sexual size dimorphism (SSD) has gained inconsistent support, that strong fecundity selection does not necessarily drive female-biased SSD, and that this form of SSD can be driven by other selective pressures; and (vi) discuss cases in which fecundity selection operates on males. This conceptual analysis of the theory of fecundity selection promises to help illuminate one of the central components of fitness and its contribution to adaptive evolution. © 2015 Cambridge Philosophical Society.
Concerted evolution of life stage performances signals recent selection on yeast nitrogen use.
Ibstedt, Sebastian; Stenberg, Simon; Bagés, Sara; Gjuvsland, Arne B; Salinas, Francisco; Kourtchenko, Olga; Samy, Jeevan K A; Blomberg, Anders; Omholt, Stig W; Liti, Gianni; Beltran, Gemma; Warringer, Jonas
2015-01-01
Exposing natural selection driving phenotypic and genotypic adaptive differentiation is an extraordinary challenge. Given that an organism's life stages are exposed to the same environmental variations, we reasoned that fitness components, such as the lag, rate, and efficiency of growth, directly reflecting performance in these life stages, should often be selected in concert. We therefore conjectured that correlations between fitness components over natural isolates, in a particular environmental context, would constitute a robust signal of recent selection. Critically, this test for selection requires fitness components to be determined by different genetic loci. To explore our conjecture, we exhaustively evaluated the lag, rate, and efficiency of asexual population growth of natural isolates of the model yeast Saccharomyces cerevisiae in a large variety of nitrogen-limited environments. Overall, fitness components were well correlated under nitrogen restriction. Yeast isolates were further crossed in all pairwise combinations and coinheritance of each fitness component and genetic markers were traced. Trait variations tended to map to quantitative trait loci (QTL) that were private to a single fitness component. We further traced QTLs down to single-nucleotide resolution and uncovered loss-of-function mutations in RIM15, PUT4, DAL1, and DAL4 as the genetic basis for nitrogen source use variations. Effects of SNPs were unique for a single fitness component, strongly arguing against pleiotropy between lag, rate, and efficiency of reproduction under nitrogen restriction. The strong correlations between life stage performances that cannot be explained by pleiotropy compellingly support adaptive differentiation of yeast nitrogen source use and suggest a generic approach for detecting selection. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Reliability and Productivity Modeling for the Optimization of Separated Spacecraft Interferometers
NASA Technical Reports Server (NTRS)
Kenny, Sean (Technical Monitor); Wertz, Julie
2002-01-01
As technological systems grow in capability, they also grow in complexity. Due to this complexity, it is no longer possible for a designer to use engineering judgement to identify the components that have the largest impact on system life cycle metrics, such as reliability, productivity, cost, and cost effectiveness. One way of identifying these key components is to build quantitative models and analysis tools that can be used to aid the designer in making high level architecture decisions. Once these key components have been identified, two main approaches to improving a system using these components exist: add redundancy or improve the reliability of the component. In reality, the most effective approach to almost any system will be some combination of these two approaches, in varying orders of magnitude for each component. Therefore, this research tries to answer the question of how to divide funds, between adding redundancy and improving the reliability of components, to most cost effectively improve the life cycle metrics of a system. While this question is relevant to any complex system, this research focuses on one type of system in particular: Separate Spacecraft Interferometers (SSI). Quantitative models are developed to analyze the key life cycle metrics of different SSI system architectures. Next, tools are developed to compare a given set of architectures in terms of total performance, by coupling different life cycle metrics together into one performance metric. Optimization tools, such as simulated annealing and genetic algorithms, are then used to search the entire design space to find the "optimal" architecture design. Sensitivity analysis tools have been developed to determine how sensitive the results of these analyses are to uncertain user defined parameters. Finally, several possibilities for the future work that could be done in this area of research are presented.
Lifetime Reliability Prediction of Ceramic Structures Under Transient Thermomechanical Loads
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Jadaan, Osama J.; Gyekenyesi, John P.
2005-01-01
An analytical methodology is developed to predict the probability of survival (reliability) of ceramic components subjected to harsh thermomechanical loads that can vary with time (transient reliability analysis). This capability enables more accurate prediction of ceramic component integrity against fracture in situations such as turbine startup and shutdown, operational vibrations, atmospheric reentry, or other rapid heating or cooling situations (thermal shock). The transient reliability analysis methodology developed herein incorporates the following features: fast-fracture transient analysis (reliability analysis without slow crack growth, SCG); transient analysis with SCG (reliability analysis with time-dependent damage due to SCG); a computationally efficient algorithm to compute the reliability for components subjected to repeated transient loading (block loading); cyclic fatigue modeling using a combined SCG and Walker fatigue law; proof testing for transient loads; and Weibull and fatigue parameters that are allowed to vary with temperature or time. Component-to-component variation in strength (stochastic strength response) is accounted for with the Weibull distribution, and either the principle of independent action or the Batdorf theory is used to predict the effect of multiaxial stresses on reliability. The reliability analysis can be performed either as a function of the component surface (for surface-distributed flaws) or component volume (for volume-distributed flaws). The transient reliability analysis capability has been added to the NASA CARES/ Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code. CARES/Life was also updated to interface with commercially available finite element analysis software, such as ANSYS, when used to model the effects of transient load histories. Examples are provided to demonstrate the features of the methodology as implemented in the CARES/Life program.
Prediction of life stress on athletes’ burnout: the dual role of perceived stress
Wang, Erica T.W.; Hsu, Ya-Wen; Chang, Ko-Hsin
2018-01-01
Although many studies adopted Smith’s (1986) cognitive–affective model of athletic burnout in examining stress–burnout relationship, very few studies examined the mediating/moderating role of perceived stress on the stress–burnout relationship. We sampled 195 college student-athletes and assessed their life stress, perceived stress, and burnout. Correlation analyses found all study variables correlated. Two separate hierarchical regression analyses found that the “distress” component of perceived stress mediated athletes’ two types of life stress–burnout relationship but “counter-stress” component of perceived stress-moderated athletes’ general-life stress–burnout relationship. We concluded that interweaving relationships among athletes’ life stress, perceived stress, and burnout are not straightforward. Future research should consider the nature of athletes life stress, and dual role of perceived stress in examining its’ association with related psychological responses in athletic settings. PMID:29362691
NASA Technical Reports Server (NTRS)
Effinger, Michael; Ellingson, Bill; Spohnholtz, Todd; Koenig, John
2000-01-01
Damping measurements have been taken on ceramic matrix composite (CMC) turbopump blisks in the as fabricated, post proof testing, and post turbopump testing conditions. These results indicate that damping is able to quantify fatigue of the CMC blisk. This gives hope for the potential of determining the actual and residual life of CMC materials using a combination of nondestructive techniques. If successful, then this new paradigm for life prediction of CMCs could revolutionize the approach for designing and servicing CMC components, thereby significantly reducing costs for design, development, health monitoring, and maintenance of CMC components and systems. The Nondestructive Characterization (NDC) life prediction approach would complement life prediction using micromechanics and continuum finite element models. This paper reports on the initial concept of NDC life prediction and how changes in damping and ultrasonic elastic modulus data have established the concept as a possibility.
Accelerated life assessment of coating on the radar structure components in coastal environment.
Liu, Zhe; Ming, ZhiMao
2016-07-04
This paper aimed to build an accelerated life test scheme and carry out quantitative analysis between accelerated life test in the laboratory and actual service for the coating composed of epoxy primer and polyurethane paint on structure components of some kind of radar served in the coastal environment of South China Sea. The accelerated life test scheme was built based on the service environment and failure analysis of the coating. The quantitative analysis between accelerated life test and actual service was conducted by comparing the gloss loss, discoloration, chalking, blistering, cracking and electrochemical impedance spectroscopy of the coating. The main factors leading to the coating failure were ultraviolet radiation, temperature, moisture, salt fog and loads, the accelerated life test included ultraviolet radiation, damp heat, thermal shock, fatigue and salt spray. The quantitative relationship was that one cycle of the accelerated life test was equal to actual service for one year. It was established that one cycle of the accelerated life test was equal to actual service for one year. It provided a precise way to predict actual service life of newly developed coatings for the manufacturer.
Structural Analysis of Pyrolytic Graphite Optics for the HiPEP Ion Thruster
NASA Technical Reports Server (NTRS)
Meckel, Nicole; Polaha, Jonathan; Juhlin, Nils
2006-01-01
The long lifetime requirements of interplanetary exploration missions is driving the need to develop long-life components for the electric propulsion thrusters that are being targeted for these missions. One of the primary life-limiting components of ion thrusters are the optics, which are continuously eroded during the operation of the thruster. Pyrolytic graphite optics are being considered for the High Power Electric Propulsion (HiPEP) ion thruster because of their very high resistance to erosion. This paper describes the structural analysis of the HiPEP pyrolytic graphite. A description of the development of the grid model, as well as the development of the effective properties and stress concentrations in the apertured area of the grids is included. An evaluation of the use of curved grids shows that the increased stiffness (compared to flat grids) prevents intergrid impact during launch, however, the residual stresses introduced by curving the grids pushes the resulting peak stresses beyond the critical stress. As a result, flat grids are recommended as the design solution. Thermally induced grid displacements during normal thruster operation are also presented.
Retired flies, hidden plateaus, and the evolution of senescence in Drosophila melanogaster.
Curtsinger, James W
2016-06-01
Late-life plateaus in age-specific mortality have been an evolutionary and biodemographic puzzle for decades. Although classic theory on the evolution of senescence predicts late-life walls of death, observations in experimental organisms document the opposite trend: a slowing in the rate of increase of mortality at advanced ages. Here, I analyze published life-history data on individual Drosophila melanogaster females and argue for a fundamental change in our understanding of mortality in this important model system. Mortality plateaus are not, as widely assumed, exclusive to late life, and are not explained by population heterogeneity-they are intimately connected to individual fecundity. Female flies begin adult life in the working stage, a period of active oviposition and low but accelerating mortality. Later they transition to the retired stage, a terminal period characterized by limited fecundity and relatively constant mortality. Because ages of transition differ between flies, age-synchronized cohorts contain a mix of working and retired flies. Early- and mid-life plateaus are obscured by the presence of working flies, but can be detected when cohorts are stratified by retirement status. Stage-specificity may be an important component of Drosophila life-history evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
Fructose, pregnancy and later life impacts.
Regnault, Timothy R H; Gentili, Sheridan; Sarr, Ousseynou; Toop, Carla R; Sloboda, Deborah M
2013-11-01
Fructose is an increasingly common constituent of the Westernized diet due to cost and production efficiencies. Although an integral component of our pre-industrial revolution diet, over the past two decades human and animal studies have highlighted that excessive fructose intake appears to be associated with adverse metabolic effects. Excessive intake of fructose is the combined result of increased total energy consumption and increased portion sizes of foods, which often incorporate the fructose-containing sugars sucrose and high-fructose corn-syrup (HFCS). The adverse metabolic effects following excessive fructose consumption have become a hot topic in mainstream media and there is now rigorous scientific debate regarding periods of exposure, dosage levels, interactive effects with other sugars and fats and mechanisms underlying the actions of fructose. There is still a degree of controversy regarding the extent to which sugars such as sucrose and HFCS have contributed to the current epidemic of obesity and diabetes. Furthermore, an increasing number of infants are being exposed to sugar-sweetened food and beverages before birth and during early postnatal life, highlighting the importance of determining the long-term effects of this perinatal exposure on the developing offspring. There are limited human observational and controlled studies identifying associations of excessive sweetened food and beverage consumption with poor pregnancy outcomes. Animal research has demonstrated an increased incidence of gestational diabetes as well as altered maternal, fetal and offspring metabolic function, although the long-term effects and the mechanism underlying these perturbations are ill defined. This review aims to understand the role of early life fructose exposure in modifying postnatal risk of disease in the offspring, focusing on fructose intake during pregnancy and in early postnatal life. © 2013 Wiley Publishing Asia Pty Ltd.
Gaygisiz, Esma
2010-06-01
The correlations among indicators of objective well-being, cultural dimensions, and subjective well-being were investigated using Organisation for Economic Co-operation and Development (OECD) data from 35 countries. The subjective well-being measures included life satisfaction as well as six positive and six negative indexes of experience. Positive and negative experience scores were subjected to principal component analysis, and two positive experience components (labeled as "positive experiences" and "time management") and two negative experience components (labeled as "pain, worry, and sadness" and "anger and boredom") were extracted. Objective well-being included economic indicators, education, and health. The cultural variables included Hofstede's and Schwartz's cultural dimensions, national Big Five personality scores, and national IQs. High life satisfaction was positively related to Gross Domestic Product, life expectancy, education, individualism, affective and intellectual autonomy, egalitarianism, and conscientiousness, whereas low life satisfaction was related to unemployment, unequal income distribution, power distance, masculinity uncertainty avoidance, embeddedness, hierarchy, and neuroticism.
Scaling Impacts in Life Support Architecture and Technology Selection
NASA Technical Reports Server (NTRS)
Lange, Kevin
2016-01-01
For long-duration space missions outside of Earth orbit, reliability considerations will drive higher levels of redundancy and/or on-board spares for life support equipment. Component scaling will be a critical element in minimizing overall launch mass while maintaining an acceptable level of system reliability. Building on an earlier reliability study (AIAA 2012-3491), this paper considers the impact of alternative scaling approaches, including the design of technology assemblies and their individual components to maximum, nominal, survival, or other fractional requirements. The optimal level of life support system closure is evaluated for deep-space missions of varying duration using equivalent system mass (ESM) as the comparative basis. Reliability impacts are included in ESM by estimating the number of component spares required to meet a target system reliability. Common cause failures are included in the analysis. ISS and ISS-derived life support technologies are considered along with selected alternatives. This study focusses on minimizing launch mass, which may be enabling for deep-space missions.
Life Esteem: Quantitative and Qualitative Differences.
ERIC Educational Resources Information Center
Wheeler, Robert J.
The development of humanistic psychology has stimulated research that supports the importance of life esteem, or the way people view meaning and purpose in their lives. The Life Esteem survey is a self-report questionnaire designed to measure the four components of life esteem (framework, perspective, commitment, quality) and to assess the…
Self-esteem, social participation, and quality of life in patients with multiple sclerosis.
Mikula, Pavol; Nagyova, Iveta; Krokavcova, Martina; Vitkova, Marianna; Rosenberger, Jaroslav; Szilasiova, Jarmila; Gdovinova, Zuzana; Stewart, Roy E; Groothoff, Johan W; van Dijk, Jitse P
2017-07-01
The aim of this study is to explore whether self-esteem and social participation are associated with the physical and mental quality of life (Physical Component Summary, Mental Component Summary) and whether self-esteem can mediate the association between these variables. We collected information from 118 consecutive multiple sclerosis patients. Age, gender, disease duration, disability status, and participation were significant predictors of Physical Component Summary, explaining 55.4 percent of the total variance. Self-esteem fully mediated the association between social participation and Mental Component Summary (estimate/standard error = -4.872; p < 0.001) and along with disability status explained 48.3 percent of the variance in Mental Component Summary. These results can be used in intervention and educational programs.
Mi, Baibing; Dang, Shaonong; Li, Qiang; Zhao, Yaling; Yang, Ruihai; Wang, Duolao; Yan, Hong
2015-07-01
Hypertensive patients have more complex health care needs and are more likely to have poorer health-related quality of life than normotensive people. The awareness of hypertension could be related to reduce health-related quality of life. We propose the use of quantile regression to explore more detailed relationships between awareness of hypertension and health-related quality of life. In a cross-sectional, population-based study, 2737 participants (including 1035 hypertensive patients and 1702 normotensive participants) completed the Short-Form Health Survey. A quantile regression model was employed to investigate the association of physical component summary scores and mental component summary scores with awareness of hypertension and to evaluate the associated factors. Patients who were aware of hypertension (N = 554) had lower scores than patients who were unaware of hypertension (N = 481). The median (IQR) of physical component summary scores: 48.20 (13.88) versus 53.27 (10.79), P < 0.01; the mental component summary scores: 50.68 (15.09) versus 51.70 (10.65), P = 0.03. adjusting for covariates, the quantile regression results suggest awareness of hypertension was associated with most physical component summary scores quantiles (P < 0.05 except 10th and 20th quantiles) in which the β-estimates from -2.14 (95% CI: -3.80 to -0.48) to -1.45 (95% CI: -2.42 to -0.47), as the same significant trend with some poorer mental component summary scores quantiles in which the β-estimates from -3.47 (95% CI: -6.65 to -0.39) to -2.18 (95% CI: -4.30 to -0.06). The awareness of hypertension has a greater effect on those with intermediate physical component summary status: the β-estimates were equal to -2.04 (95% CI: -3.51 to -0.57, P < 0.05) at the 40th and decreased further to -1.45 (95% CI: -2.42 to -0.47, P < 0.01) at the 90th quantile. Awareness of hypertension was negatively related to health-related quality of life in hypertensive patients in rural western China, which has a greater effect on mental component summary scores with the poorer status and on physical component summary scores with the intermediate status.
Saastamoinen, Marjo; van der Sterren, Dominique; Vastenhout, Nienke; Zwaan, Bas J; Brakefield, Paul M
2010-12-01
The experience of environmental stress during development can substantially affect an organism's life history. These effects are often mainly negative, but a growing number of studies suggest that under certain environmental conditions early experience of such stress may yield individuals that are less sensitive to environmental stress later on in life. We used the butterfly Bicyclus anynana to study the effects of limited larval and adult food and forced flight on individual performance measured as reproduction and adult life span. Larvae exposed to food stress showed longer development and produced smaller adults. Thus, they were not able to fully compensate for the food deprivation during development. Females that experienced food stress during development did not increase tolerance for adult food limitation. However, females exposed to food stress during development coped better with forced flight compared with the control group. The apparent absence of costs of flight in poor-quality females may be a by-product of an altered body allocation, as females experiencing both food stress treatments had increased thorax ratios, compared with controls, and increased flight performances. The results reveal an important plasticity component to variation in flight performance and suggest that the cost of flight depends on an individual's internal condition.
NASALife-Component Fatigue and Creep Life Prediction Program and Illustrative Examples
NASA Technical Reports Server (NTRS)
Murthy, Pappu L. N.; Mital, Subodh K.; Gyekenyesi, John Z.
2005-01-01
NASALife is a life prediction program for propulsion system components made of ceramic matrix composites (CMC) under cyclic thermo-mechanical loading and creep rupture conditions. Although, the primary focus was for CMC components the underlying methodologies are equally applicable to other material systems as well. The program references data for low cycle fatigue (LCF), creep rupture, and static material properties as part of the life prediction process. Multiaxial stresses are accommodated by Von Mises based methods and a Walker model is used to address mean stress effects. Varying loads are reduced by the Rainflow counting method. Lastly, damage due to cyclic loading (Miner s rule) and creep are combined to determine the total damage per mission and the number of missions the component can survive before failure are calculated. Illustration of code usage is provided through example problem of a CMC turbine stator vane made of melt-infiltrated, silicon carbide fiber-reinforced, silicon carbide matrix composite (MI SiC/SiC)
The Influence Of Component Alignment On The Life Of Total Knee Prostheses
NASA Astrophysics Data System (ADS)
Bugariu, Delia; Bereteu, Liviu
2012-12-01
An arthritic knee affects the patient's life by causing pain and limiting movement. If the cartilage and the bone surfaces are severely affected, the natural joint is replaced with an artificial joint. The procedure is called total knee arthroplasty (TKA). Lately, the numbers of implanted total knee prostheses grow steadily. An important factor in TKA is the perfect alignment of the total knee prosthesis (TKP) components. Component misalignment can lead to the prosthesis loss by producing wear particles. The paper proposes a study on mechanical behaviors of a TKP based on numerical analysis, using ANSYS software. The numerical analysis is based on both the normal and the changed angle of the components alignment.
NASA Astrophysics Data System (ADS)
Gobbato, Maurizio; Kosmatka, John B.; Conte, Joel P.
2014-04-01
Fatigue-induced damage is one of the most uncertain and highly unpredictable failure mechanisms for a large variety of mechanical and structural systems subjected to cyclic and random loads during their service life. A health monitoring system capable of (i) monitoring the critical components of these systems through non-destructive evaluation (NDE) techniques, (ii) assessing their structural integrity, (iii) recursively predicting their remaining fatigue life (RFL), and (iv) providing a cost-efficient reliability-based inspection and maintenance plan (RBIM) is therefore ultimately needed. In contribution to these objectives, the first part of the paper provides an overview and extension of a comprehensive reliability-based fatigue damage prognosis methodology — previously developed by the authors — for recursively predicting and updating the RFL of critical structural components and/or sub-components in aerospace structures. In the second part of the paper, a set of experimental fatigue test data, available in the literature, is used to provide a numerical verification and an experimental validation of the proposed framework at the reliability component level (i.e., single damage mechanism evolving at a single damage location). The results obtained from this study demonstrate (i) the importance and the benefits of a nearly continuous NDE monitoring system, (ii) the efficiency of the recursive Bayesian updating scheme, and (iii) the robustness of the proposed framework in recursively updating and improving the RFL estimations. This study also demonstrates that the proposed methodology can lead to either an extent of the RFL (with a consequent economical gain without compromising the minimum safety requirements) or an increase of safety by detecting a premature fault and therefore avoiding a very costly catastrophic failure.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ismail, R., E-mail: rifky-mec@yahoo.com; Tauviqirrahman, M., E-mail: rifky-mec@yahoo.com; Laboratory for Surface Technology and Tribology, Faculty of Engineering Technology, University of Twente, Enschede
This paper reviews the development of new material and surface technology in tribology and its contribution to energy efficiency. Two examples of the economic benefits, resulted from the optimum tribology in the transportation sector and the manufacturing industry are discussed. The new materials are proposed to modify the surface property by laminating the bulk material with thin layer/coating. Under a suitable condition, the thin layer on a surface can provide a combination of good wear, a low friction and corrosion resistance for the mechanical components. The innovation in layer technology results molybdenum disulfide (MoS2), diamond like carbon (DLC), cubic boronmore » nitride (CBN) and diamond which perform satisfactory outcome. The application of the metallic coatings to carbon fibre reinforced polymer matrix composites (CFRP) has the capacity to provide considerable weight and power savings for many engineering components. The green material for lubricant and additives such as the use of sunflower oil which possesses good oxidation resistance and the use of mallee leaves as bio‐degradable solvent are used to answer the demand of the environmentally friendly material with good performance. The tribology research implementation for energy efficiency also touches the simple things around us such as: erasing the laser‐print in a paper with different abrasion techniques. For the technology in the engineering surface, the consideration for generating the suitable surface of the components in running‐in period has been discussed in order to prolong the components life and reduce the machine downtime. The conclusion, tribology can result in reducing manufacturing time, reducing the maintenance requirements, prolonging the service interval, improving durability, reliability and mechanical components life, and reducing harmful exhaust emission and waste. All of these advantages will increase the energy efficiency and the economic benefits.« less
NASA Astrophysics Data System (ADS)
Ismail, R.; Tauviqirrahman, M.; Jamari, Jamari; Schipper, D. J.
2009-09-01
This paper reviews the development of new material and surface technology in tribology and its contribution to energy efficiency. Two examples of the economic benefits, resulted from the optimum tribology in the transportation sector and the manufacturing industry are discussed. The new materials are proposed to modify the surface property by laminating the bulk material with thin layer/coating. Under a suitable condition, the thin layer on a surface can provide a combination of good wear, a low friction and corrosion resistance for the mechanical components. The innovation in layer technology results molybdenum disulfide (MoS2), diamond like carbon (DLC), cubic boron nitride (CBN) and diamond which perform satisfactory outcome. The application of the metallic coatings to carbon fibre reinforced polymer matrix composites (CFRP) has the capacity to provide considerable weight and power savings for many engineering components. The green material for lubricant and additives such as the use of sunflower oil which possesses good oxidation resistance and the use of mallee leaves as bio-degradable solvent are used to answer the demand of the environmentally friendly material with good performance. The tribology research implementation for energy efficiency also touches the simple things around us such as: erasing the laser-print in a paper with different abrasion techniques. For the technology in the engineering surface, the consideration for generating the suitable surface of the components in running-in period has been discussed in order to prolong the components life and reduce the machine downtime. The conclusion, tribology can result in reducing manufacturing time, reducing the maintenance requirements, prolonging the service interval, improving durability, reliability and mechanical components life, and reducing harmful exhaust emission and waste. All of these advantages will increase the energy efficiency and the economic benefits.
NASA Astrophysics Data System (ADS)
Slenzka, Klaus; Duenne, Matthias
Solar system exploration with extended stays in totally closed habitats far away from Earth as well as longer stays in LEO requires intensive preparatory activities. Activities supporting life in a more or less close meaning are essential in this context -on a scientific as well as on a technical level. These needed activities are supporting life by e.g.: i) increasing knowledge about the impact of single and combined effects of different exploration related environmental conditions (e. g. microgravity, radiation, reduced pressure and temperature, lunar soil etc.) on biological systems. This is needed to enable safe life of humans itself as well as safe operating of required bioregenerative life support systems. Thus, different human cell types as well as representatives of bioregenerative life support system protagonists (algae, bacteria as well as higher organisms) needs to be addressed. ii) provision of required consumables (oxygen, food, energy equivalents etc.) on site, mainly via bioregenerative life support systems, Bio-ISRU-units etc. Preparation is needed on a scientific as well as technological level. iii) ensuring reduced negative effects on humans (and partially also equipment), which could be caused by living in a closed habitat in general (and thus being not space related per se): E. g. detection systems for the quality of water and air, antimicrobial and selfhealing as well as anti-icing materials without dangerous hazard substances, psychological health enhancing components etc. Referring payloads for above mentioned investigations (scientific evaluation and technology demonstration) must be developed. Extended stays and extended closure in habitats without the possibility of material transport into and out of the system are leading to the necessity of more autonomous technologies and sustainable processes. Latter one will rely mainly on biological processes and structures, which increases additionally the necessity of an intensive scientific and technological verification before routine use under extreme conditions during solar system exploration.
Antiretroviral therapy as HIV prevention: status and prospects.
Mayer, Kenneth H; Venkatesh, Kartik K
2010-10-01
As antiretroviral treatment of HIV infection has become increasingly accessible, attention has focused on whether these drugs can used for prevention because of increased tolerability of newer medications, decreased cost, and the limitations of other approaches. We review the status of antiretroviral HIV prevention, including chemoprophylaxis, as well as the effects of treatment of infected individuals on prevention. It is possible that the life-saving agents that have transformed the natural history of AIDS can be a critical component of HIV prevention efforts, but their ultimate role in affecting HIV transmission dynamics remains to be defined.
NASA Technical Reports Server (NTRS)
Sankararaman, Shankar; Goebel, Kai
2013-01-01
This paper investigates the use of the inverse first-order reliability method (inverse- FORM) to quantify the uncertainty in the remaining useful life (RUL) of aerospace components. The prediction of remaining useful life is an integral part of system health prognosis, and directly helps in online health monitoring and decision-making. However, the prediction of remaining useful life is affected by several sources of uncertainty, and therefore it is necessary to quantify the uncertainty in the remaining useful life prediction. While system parameter uncertainty and physical variability can be easily included in inverse-FORM, this paper extends the methodology to include: (1) future loading uncertainty, (2) process noise; and (3) uncertainty in the state estimate. The inverse-FORM method has been used in this paper to (1) quickly obtain probability bounds on the remaining useful life prediction; and (2) calculate the entire probability distribution of remaining useful life prediction, and the results are verified against Monte Carlo sampling. The proposed methodology is illustrated using a numerical example.
Signal Detection Theory Applied to Helicopter Transmission Diagnostic Thresholds
NASA Technical Reports Server (NTRS)
Dempsey, Paula J.; Keller, Jonathan A.; Wade, Daniel R.
2008-01-01
Helicopter Health Usage Monitoring Systems (HUMS) have potential for providing data to support increasing the service life of a dynamic mechanical component in the transmission of a helicopter. Data collected can demonstrate the HUMS condition indicator responds to a specific component fault with appropriate alert limits and minimal false alarms. Defining thresholds for specific faults requires a tradeoff between the sensitivity of the condition indicator (CI) limit to indicate damage and the number of false alarms. A method using Receiver Operating Characteristic (ROC) curves to assess CI performance was demonstrated using CI data collected from accelerometers installed on several UH60 Black Hawk and AH64 Apache helicopters and an AH64 helicopter component test stand. Results of the analysis indicate ROC curves can be used to reliably assess the performance of commercial HUMS condition indicators to detect damaged gears and bearings in a helicopter transmission.
Silva, Juliana; Monge-Fuentes, Victoria; Gomes, Flávia; Lopes, Kamila; dos Anjos, Lilian; Campos, Gabriel; Arenas, Claudia; Biolchi, Andréia; Gonçalves, Jacqueline; Galante, Priscilla; Campos, Leandro; Mortari, Márcia
2015-01-01
Neurodegenerative diseases are relentlessly progressive, severely impacting affected patients, families and society as a whole. Increased life expectancy has made these diseases more common worldwide. Unfortunately, available drugs have insufficient therapeutic effects on many subtypes of these intractable diseases, and adverse effects hamper continued treatment. Wasp and bee venoms and their components are potential means of managing or reducing these effects and provide new alternatives for the control of neurodegenerative diseases. These venoms and their components are well-known and irrefutable sources of neuroprotectors or neuromodulators. In this respect, the present study reviews our current understanding of the mechanisms of action and future prospects regarding the use of new drugs derived from wasp and bee venom in the treatment of major neurodegenerative disorders, including Alzheimer’s Disease, Parkinson’s Disease, Epilepsy, Multiple Sclerosis and Amyotrophic Lateral Sclerosis. PMID:26295258
Signal Detection Theory Applied to Helicopter Transmission Diagnostic Thresholds
NASA Technical Reports Server (NTRS)
Dempsey, Paula J.; Keller, Jonathan A.; Wade, Daniel R.
2009-01-01
Helicopter Health Usage Monitoring Systems (HUMS) have potential for providing data to support increasing the service life of a dynamic mechanical component in the transmission of a helicopter. Data collected can demonstrate the HUMS condition indicator responds to a specific component fault with appropriate alert limits and minimal false alarms. Defining thresholds for specific faults requires a tradeoff between the sensitivity of the condition indicator (CI) limit to indicate damage and the number of false alarms. A method using Receiver Operating Characteristic (ROC) curves to assess CI performance was demonstrated using CI data collected from accelerometers installed on several UH60 Black Hawk and AH64 Apache helicopters and an AH64 helicopter component test stand. Results of the analysis indicate ROC curves can be used to reliably assess the performance of commercial HUMS condition indicators to detect damaged gears and bearings in a helicopter transmission.
High Temperature Corrosion Problem of Boiler Components in presence of Sulfur and Alkali based Fuels
NASA Astrophysics Data System (ADS)
Ghosh, Debashis; Mitra, Swapan Kumar
2011-04-01
Material degradation and ageing is of particular concern for fossil fuel fired power plant components. New techniques/approaches have been explored in recent years for Residual Life assessment of aged components and material degradation due to different damage mechanism like creep, fatigue, corrosion and erosion etc. Apart from the creep, the high temperature corrosion problem in a fossil fuel fired boiler is a matter of great concern if the fuel contains sulfur, chlorine sodium, potassium and vanadium etc. This paper discusses the material degradation due to high temperature corrosion in different critical components of boiler like water wall, superheater and reheater tubes and also remedial measures to avoid the premature failure. This paper also high lights the Residual Life Assessment (RLA) methodology of the components based on high temperature fireside corrosion. of different critical components of boiler.
NASA Astrophysics Data System (ADS)
Fernandez, M.; Ruddell, A. J.; Vast, N.; Esteban, J.; Estela, F.
There are many applications and uses for which it is more advantageous to use solar installations than to extend the electrical network and connect to it. This kind of applications are numerous covering from isolated houses to telephone repeaters and the like. These kind of applications share some common characteristics like being located in remote not easy accessible areas, require relatively low power for operation, and being difficult to maintain. Up to now the use of photovoltaic systems, no matter the impressive growth they are experimenting, suffer from some drawbacks, mainly related with the life expectations and reliability of such systems, and as a consequence of the cost of these systems, when calculated on a lifetime basis. To try to contribute to solve these problems, a project partially founded by the European Commission, has been carried out, with the main objective of increasing the life of these systems, and consequently to make them more attractive from the point of view of cost on a lifetime basis for consumers. Presently, the life of PV systems is limited by its weakest component, the battery. Battery failure modes in PV applications, are related with well known phenomena like corrosion, but also due to the special nature of this installations, with other factors like corrosion and growth in the upper part of the group, induced by the development of acid stratification inside the battery, with the more prone standard flooded types now in major use, and to a lesser extent the new valve regulated lead acid (VRLA) types beginning to be used. The main objectives of this project, were: to develop a new glass microfibre separator material, capable of minimizing acid stratification inside the battery. To develop a new VRLA battery, with a life duration of 800 cycles on cycling at 60% DOD and partial state of charge (PSOC) conditions. To develop a new charge regulator, that takes into account the condition of the battery in the near term, to modify its setting charging point. The fourth objective was the design and implementation of a PV/wind demonstration system, to test all the PV components under real conditions. The project has been successful, having achieved a life increase of 50%, moving achievable life from previous 500-750 cycles for the new battery and system.
Fenouillet, Emmanuel; Vigouroux, Aude; Steinberg, Jean Guillaume; Chagvardieff, Alexandre; Retornaz, Frédérique; Guieu, Regis; Jammes, Yves
2016-08-31
Myalgic encephalomyelitis chronic fatigue syndrome (ME/CFS) is a common debilitating disorder associated with an intense fatigue, a reduced physical activity, and an impaired quality of life. There are no established biological markerof the syndrome. The etiology is unknown and its pathogenesis appears to be multifactorial. Various stressors, including intense physical activity, severe infection, and emotional stress are reported in the medical history of ME/CFS patients which raises the question whether any physiological and biological abnormalities usually found in these patients could be indicative of the etiology and/or the quality-of-life impairment. Thirty-six patients and 11 age-matched healthy controls were recruited. The following variables that appear to address common symptoms of ME/CFS were studied here: (1) muscle fatigue during exercise has been investigated by monitoring the compound muscle action potential (M-wave); (2) the excessive oxidative stress response to exercise was measured via two plasma markers (thiobarbituric acid reactive substances: TBARS; reduced ascorbic-acid: RAA); (3) a potential inflammatory component was addressed via expression of CD26 on peripheral blood mononuclear cells; (4) quality-of-life impairment was assessed using the London Handicap Scale (LHS) and the Medical Outcome Study Short Form-36 (SF-36). The medical history of each patient, including the presence of stressors such as intense sports practice, severe acute infection and/or severe emotional stress was documented. We observed that: (1) there were striking differences between cases and controls with regard to three biological variables: post-exercise M-wave, TBARS variations and CD26-expression at rest; (2) each of these three variables correlated with the other two; (3) abnormalities in the biomarkers associated with health-related quality of life: the LHS score was negatively correlated with the exercise-induced TBARS increase and positively correlated with CD26-expression while the pain component of SF-36 was negatively correlated with CD26-expression; (4) the TBARS increase and the M-wave decrease were the highest, and the CD26-expression level the lowest in patients who had been submitted to infectious stressors. In ME/CFS patients, severe alterations of the muscle excitability, the redox status, as well as the CD26-expression level are correlated with a marked impairment of the quality-of-life. They are particularly significant when infectious stressors are reported in the medical history.
Kale, Hrishikesh P; Carroll, Norman V
2016-04-15
Cancer-related financial burden has been linked to cancer survivors (CS) forgoing/delaying medical care, skipping follow-up visits, and discontinuing medications. To the authors' knowledge, little is known regarding the effect of financial burden on the health-related quality of life of CS. The authors analyzed 2011 Medical Expenditure Panel Survey data. Financial burden was present if one of the following problems was reported: borrowed money/declared bankruptcy, worried about paying large medical bills, unable to cover the cost of medical care visits, or other financial sacrifices. The following outcomes were evaluated: Physical Component Score (PCS) and Mental Component Score (MCS) of the 12-Item Short-Form Health Survey (SF-12), depressed mood, psychological distress, and worry related to cancer recurrence. The authors also assessed the effect of the number of financial problems on these outcomes. Of the 19.6 million CS analyzed, 28.7% reported financial burden. Among them, the average PCS (42.3 vs 44.9) and MCS (48.1 vs 52.1) were lower for those with financial burden versus those without. In adjusted analyses, CS with financial burden had significantly lower PCS (β = -2.45), and MCS (β = -3.05), had increased odds of depressed mood (odds ratio, 1.95), and were more likely to worry about cancer recurrence (odds ratio, 3.54). Survivors reporting ≥ 3 financial problems reported statistically significant and clinically meaningful differences (≥3 points) in the mean PCS and MCS compared with survivors without financial problems. Cancer-related financial burden was associated with lower health-related quality of life, increased risk of depressed mood, and a higher frequency of worrying about cancer recurrence among CS. © 2015 American Cancer Society.
Goh, Graham Seow-Hng; Liow, Ming Han Lincoln; Bin Abd Razak, Hamid Rahmatullah; Tay, Darren Keng-Jin; Lo, Ngai-Nung; Yeo, Seng-Jin
2017-02-01
Recent studies have shown a discrepancy between traditional functional outcomes and patient satisfaction, with some reporting less than 85% satisfaction in older patients undergoing total knee arthroplasty (TKA). As native knee biomechanics are not completely replicated, the resulting functional limitations may cause dissatisfaction in higher-demand individuals. Few studies have recorded patient-reported outcomes, health-related quality of life scores, and patient satisfaction in a young population undergoing TKA. One hundred thirty-six primary TKAs were performed in 114 patients aged 50 years or younger (mean age, 47.0 years; range, 30-50 years) at a single institution. The main diagnoses were osteoarthritis (85%) and rheumatoid arthritis (10%). The range of motion, Knee Society Score, Oxford Knee Score, and Physical and Mental Component Scores of Short Form-36 increased significantly (P < .001). At 2 years, 85.3% of patients had good/excellent knee scores, 71.3% had good/excellent function scores, 94.9% met the minimal clinically important difference for the Oxford Knee Score, and 84.6% met the minimal clinically important difference for the Physical Component Score. We found that 88.8% of patients were satisfied with their surgeries, whereas 86.8% had their expectations fulfilled. Survivorship using revision as an end point was 97.8% at a mean of 7 years (range, 3-16 years). Patients aged 50 years or younger undergoing TKA can experience significant improvements in their quality of life, have their expectations met, and be satisfied with their surgeries, at rates similar to those of non-age-restricted populations. Surgeons should inform them of these benefits and the potential risk of revision surgery in the future, albeit increasingly shown to be low. Copyright © 2016 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Gbaguidi, Audrey J.-M.
Structural health monitoring (SHM) has become indispensable for reducing maintenance costs and increasing the in-service capacity of a structure. The increased use of lightweight composite materials in aircraft structures drastically increased the effects of fatigue induced damage on their critical structural components and thus the necessity to predict the remaining life of those components. Damage prognosis, one of the least investigated fields in SHM, uses the current damage state of the system to forecast its future performance by estimating the expected loading environments. A successful damage prediction model requires the integration of technologies in areas like measurements, materials science, mechanics of materials, and probability theories, but most importantly the quantification of uncertainty in all these areas. In this study, Affine Arithmetic is used as a method for incorporating the uncertainties due to the material properties into the fatigue life prognosis of composite plates subjected to cyclic compressive loadings. When loadings are compressive in nature, the composite plates undergo repeated buckling-unloading of the delaminated layer which induces mixed modes I and II states of stress at the tip of the delamination in the plates. The Kardomateas model-based prediction law is used to predict the growth of the delamination, while the integration of the effects of the uncertainties for modes I and II coefficients in the fatigue life prediction model is handled using Affine arithmetic. The Mode I and Mode II interlaminar fracture toughness and fatigue characterization of the composite plates are first experimentally studied to obtain the material coefficients and fracture toughness, respectively. Next, these obtained coefficients are used in the Kardomateas law to predict the delamination lengths in the composite plates while using Affine Arithmetic to handle their uncertainties. At last, the fatigue characterization of the composite plates during compressive-buckling loadings is experimentally studied, and the delamination lengths obtained are compared with the predicted values to check the performance of Affine Arithmetic as an uncertainty propagation tool.
Kement, Metin; Gezen, Cem; Aydin, Halime; Haksal, Mustafa; Can, Ugur; Aksakal, Nihat; Öncel, Mustafa
2014-10-01
The impact of having a stoma on quality of life is increasingly recognized and studied. A descriptive survey study was conducted between January 2006 and December 2011 among 44 patients (18 women, 26 men) with a permanent stoma receiving care at the Kartal Training and Research Hospital, Istanbul, Turkey, to evaluate socio-demographic factors that may affect the quality of life in Turkish Muslim patients with an enteral stoma. A socio-demographic questionnaire, a 10- item Religious Orientation Scale (Modified Allport-Ross ROS), and the Medical Outcomes Study Short Form 36 Quality of Life survey were administered by a stoma therapy nurse at least 6 months after completion of all surgical and oncological treatments. The mean follow-up period was 15.3 ± 9.7 (range 6-44) months since completion of all treatments. Data were collected using paper/pencil instruments and entered for data analysis using Student's t-tests or one-way ANOVA univariate and multivariate analyses. No significant differences were observed for income, education level, surgical history, or religion score. Gender, geographic region, and household status were found independently related to quality of life in stoma patients. Female patients had significantly lower scores than males in general health perception (P = 0.049), role emotion (P = 0.02), mental health perception (P = 0.026), and mental component (P = 0.007). Patients living in a village (four) had significantly lower scores than patients living in a big city (33) in all scales (P <0.05 for all comparisons). Village-dwelling patents also had significantly lower scores than patients living in a town (seven) in physical function (P = 0.001), vitality (P = 0.012), social function (P = 0.003), and mental component scores (P = 0.021). Patients living alone (seven) had significantly lower scores than patients living with a partner (11) in three of eight scales (physical functioning [P <0.001], role-physical [P = 0.047], and bodily pain [P = 0.015]) and physical component scores (P <0.001); they also had significantly lower scores than patients living with their families (26) in four of eight scales (physical functioning [P <0.001], role-physical [P = 0.032], bodily pain [P = 0.02], and general health perception [P=0.036]) and physical component scores (P <0.001). Although these findings provide evidence for the relationship between some socio-demographic factors on quality of life of patients with a stoma, the results of the study should be interpreted with caution; multicenter, prospective, controlled studies are needed to substantiate and clarify the relationships among these variables.
NASA Tech Briefs, July 1997. Volume 21, No. 7
NASA Technical Reports Server (NTRS)
1997-01-01
Topics: Mechanical Components; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Software; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Life Sciences.
Developing Reliable Life Support for Mars
NASA Technical Reports Server (NTRS)
Jones, Harry W.
2017-01-01
A human mission to Mars will require highly reliable life support systems. Mars life support systems may recycle water and oxygen using systems similar to those on the International Space Station (ISS). However, achieving sufficient reliability is less difficult for ISS than it will be for Mars. If an ISS system has a serious failure, it is possible to provide spare parts, or directly supply water or oxygen, or if necessary bring the crew back to Earth. Life support for Mars must be designed, tested, and improved as needed to achieve high demonstrated reliability. A quantitative reliability goal should be established and used to guide development t. The designers should select reliable components and minimize interface and integration problems. In theory a system can achieve the component-limited reliability, but testing often reveal unexpected failures due to design mistakes or flawed components. Testing should extend long enough to detect any unexpected failure modes and to verify the expected reliability. Iterated redesign and retest may be required to achieve the reliability goal. If the reliability is less than required, it may be improved by providing spare components or redundant systems. The number of spares required to achieve a given reliability goal depends on the component failure rate. If the failure rate is under estimated, the number of spares will be insufficient and the system may fail. If the design is likely to have undiscovered design or component problems, it is advisable to use dissimilar redundancy, even though this multiplies the design and development cost. In the ideal case, a human tended closed system operational test should be conducted to gain confidence in operations, maintenance, and repair. The difficulty in achieving high reliability in unproven complex systems may require the use of simpler, more mature, intrinsically higher reliability systems. The limitations of budget, schedule, and technology may suggest accepting lower and less certain expected reliability. A plan to develop reliable life support is needed to achieve the best possible reliability.
Benchmark Calibration Tests Completed for Stirling Convertor Heater Head Life Assessment
NASA Technical Reports Server (NTRS)
Krause, David L.; Halford, Gary R.; Bowman, Randy R.
2005-01-01
A major phase of benchmark testing has been completed at the NASA Glenn Research Center (http://www.nasa.gov/glenn/), where a critical component of the Stirling Radioisotope Generator (SRG) is undergoing extensive experimentation to aid the development of an analytical life-prediction methodology. Two special-purpose test rigs subjected SRG heater-head pressure-vessel test articles to accelerated creep conditions, using the standard design temperatures to stay within the wall material s operating creep-response regime, but increasing wall stresses up to 7 times over the design point. This resulted in well-controlled "ballooning" of the heater-head hot end. The test plan was developed to provide critical input to analytical parameters in a reasonable period of time.
ANALYSIS OF OUT OF DATE MCU MODIFIER LOCATED IN SRNL
DOE Office of Scientific and Technical Information (OSTI.GOV)
Crawford, C.
2014-10-22
SRNL recently completed density measurements and chemical analyses on modifier samples stored in drums within SRNL. The modifier samples date back to 2008 and are in various quantities up to 40 gallons. Vendor information on the original samples indicates a shelf life of 5 years. There is interest in determining if samples that have been stored for more than the 5 year shelf life are still acceptable for use. The Modular Caustic Side Solvent Extraction Unit (MCU) Solvent component Cs-7SB [(2,2,3,3- tetraflouropropoxy)-3-(4-sec-butylphenoxy)-2-propanol, CAS #308362-88-1] is used as a diluent modifier to increase extractant solubility and provide physical characteristics necessary formore » diluent trimming.« less
Portable Life Support Subsystem Thermal Hydraulic Performance Analysis
NASA Technical Reports Server (NTRS)
Barnes, Bruce; Pinckney, John; Conger, Bruce
2010-01-01
This paper presents the current state of the thermal hydraulic modeling efforts being conducted for the Constellation Space Suit Element (CSSE) Portable Life Support Subsystem (PLSS). The goal of these efforts is to provide realistic simulations of the PLSS under various modes of operation. The PLSS thermal hydraulic model simulates the thermal, pressure, flow characteristics, and human thermal comfort related to the PLSS performance. This paper presents modeling approaches and assumptions as well as component model descriptions. Results from the models are presented that show PLSS operations at steady-state and transient conditions. Finally, conclusions and recommendations are offered that summarize results, identify PLSS design weaknesses uncovered during review of the analysis results, and propose areas for improvement to increase model fidelity and accuracy.
Choi, Sung-Hwan; Kim, Jung-Suk; Cha, Jung-Yul; Hwang, Chung-Ju
2016-03-01
The aim of this study was to evaluate the effect of malocclusion severity on oral health-related quality of life and food intake ability in adult patients, controlling for sex, age, and the type of dental clinic visited. The sample consisted of 472 Korean patients (156 male, 316 female) with a mean age of 21.1 (SD, 8.6) years in a dental hospital and a private clinic. The correlations between the Korean version of the Oral Health Impact Profile-14 (OHIP-14K), subjective food intake ability (FIA) for 5 key foods, and Index of Orthodontic Treatment Need-Dental Health Component (IOTN-DHC) were investigated. The mean IOTN-DHC and OHIP-14K scores were significantly higher for the dental hospital patients than for the private clinic patients (IOTN-DHC, P <0.001; OHIP-14K, P <0.05). Malocclusion severity was significantly higher in male than in female subjects (P <0.001). Older patients perceived their oral health-related quality of life more negatively than did the teens (P <0.001). As the severity of the malocclusion increased, oral health-related quality of life and masticatory function worsened (OHIP-14K, P <0.001; FIA, P <0.05). As the severity of the malocclusion and the age of the patients increased, oral health-related quality of life and masticatory function relatively deteriorated. This finding provides evidence that severe malocclusions are associated with lower quality of life and less masticatory efficiency in older patients. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Determination of Turbine Blade Life from Engine Field Data
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.
2013-01-01
It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal-mechanical fatigue (TMF) as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) TMF, (2) Oxidation/erosion (O/E), and (3) Other. From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L10 blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to O/E equaled that attributed to TMF. The category that contributed most to blade failure was Other. If there were no blade failures attributed to O/E and TMF, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.
Probabilistic Prediction of Lifetimes of Ceramic Parts
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Gyekenyesi, John P.; Jadaan, Osama M.; Palfi, Tamas; Powers, Lynn; Reh, Stefan; Baker, Eric H.
2006-01-01
ANSYS/CARES/PDS is a software system that combines the ANSYS Probabilistic Design System (PDS) software with a modified version of the Ceramics Analysis and Reliability Evaluation of Structures Life (CARES/Life) Version 6.0 software. [A prior version of CARES/Life was reported in Program for Evaluation of Reliability of Ceramic Parts (LEW-16018), NASA Tech Briefs, Vol. 20, No. 3 (March 1996), page 28.] CARES/Life models effects of stochastic strength, slow crack growth, and stress distribution on the overall reliability of a ceramic component. The essence of the enhancement in CARES/Life 6.0 is the capability to predict the probability of failure using results from transient finite-element analysis. ANSYS PDS models the effects of uncertainty in material properties, dimensions, and loading on the stress distribution and deformation. ANSYS/CARES/PDS accounts for the effects of probabilistic strength, probabilistic loads, probabilistic material properties, and probabilistic tolerances on the lifetime and reliability of the component. Even failure probability becomes a stochastic quantity that can be tracked as a response variable. ANSYS/CARES/PDS enables tracking of all stochastic quantities in the design space, thereby enabling more precise probabilistic prediction of lifetimes of ceramic components.
Capacity decline of ambient temperature secondary lithium battery
NASA Technical Reports Server (NTRS)
Shen, D. H.; Subbarao, S.; Nakamura, B. J.; Yen, S. P. S.; Bankston, C. P.
1988-01-01
The use of ambient temperature secondary lithium cells is limited primarily because of the poor cycle life performance. Much of the cell capacity is irreversibly lost upon cycling. Studies have been undertaken to understand the problem of capacity decline. Experimental Li-TiS2 cells were fabricated and tested for their cycle life performance. Cells were disassembled at different stages of cycle life, and cell active components were analyzed by various analytical techniques. The results of this study indicate that all the cell's active components/materials are undergoing degradation. Details of the experiments carried out and the results obtained are described.
Zoladz, Phillip R.; Conrad, Cheryl D.; Fleshner, Monika; Diamond, David M.
2008-01-01
People who are exposed to horrific, life-threatening experiences are at risk for developing post-traumatic stress disorder (PTSD). Some of the symptoms of PTSD include persistent anxiety, exaggerated startle, cognitive impairments and increased sensitivity to yohimbine, an α2-adrenergic receptor antagonist. We have taken into account the conditions known to induce PTSD, as well as factors responsible for long-term maintenance of the disorder, to develop an animal model of PTSD. Adult male Sprague–Dawley rats were administered a total of 31 days of psychosocial stress, composed of acute and chronic components. The acute component was a 1-h stress session (immobilization during cat exposure), which occurred on Days 1 and 11. The chronic component was that on all 31 days the rats were given unstable housing conditions. We found that psychosocially stressed rats had reduced growth rate, reduced thymus weight, increased adrenal gland weight, increased anxiety, an exaggerated startle response, cognitive impairments, greater cardiovascular and corticosterone reactivity to an acute stressor and heightened responsivity to yohimbine. This work demonstrates the effectiveness of acute inescapable episodes of predator exposure administered in conjunction with daily social instability as an animal model of PTSD. PMID:18574787
Diagnostic methods for platelet bacteria screening: current status and developments.
Störmer, Melanie; Vollmer, Tanja
2014-02-01
Bacterial contamination of blood components and the prevention of transfusion-associated bacterial infection still remains a major challenge in transfusion medicine. Over the past few decades, a significant reduction in the transmission of viral infections has been achieved due to the introduction of mandatory virus screening. Platelet concentrates (PCs) represent one of the highest risks for bacterial infection. This is due to the required storage conditions for PCs in gas-permeable containers at room temperature with constant agitation, which support bacterial proliferation from low contamination levels to high titers. In contrast to virus screening, since 1997 in Germany bacterial testing of PCs is only performed as a routine quality control or, since 2008, to prolong the shelf life to 5 days. In general, bacterial screening of PCs by cultivation methods is implemented by the various blood services. Although these culturing systems will remain the gold standard, the significance of rapid methods for screening for bacterial contamination has increased over the last few years. These new methods provide powerful tools for increasing the bacterial safety of blood components. This article summarizes the course of policies and provisions introduced to increase bacterial safety of blood components in Germany. Furthermore, we give an overview of the different diagnostic methods for bacterial screening of PCs and their current applicability in routine screening processes.
LIFE CYCLE ASSESSMENT: PRINCIPLES AND PRACTICE
The following document provides an introductory overview of Life Cycle Assessment (LCA) and describes the general uses and major components of LCA. This document is an update and merger of two previous EPA documents on LCA ("Life Cycle Assessment: Inventory Guidelines and Princip...
Baptista, Liliana C; Dias, Gonçalo; Souza, Nelba R; Veríssimo, Manuel T; Martins, Raul A
2017-08-01
To establish the effect of a long-term multicomponent exercise (LTMEX) intervention (24 months) on health-related quality of life (HRQoL), in older adults with type 2 diabetes (T2D). This longitudinal retrospective cohort study analyzes the effects of a supervised LTMEX program on HRQoL in older adults with T2D (n = 279). Participants underwent one of two conditions: LTMEX (n = 241) trained three times per week; and unchanged lifestyle-the control group (CO; n = 38). Participants completed baseline, and 2-year follow-up evaluations including the Short Form Health Survey 36 (SF-36), anthropometric, hemodynamic components, and cardiorespiratory fitness (VO 2 peak). LTMEX improves HRQoL, specifically physical functioning (P < 0.001), general health (P < 0.05), vitality (P < 0.001), mental health (MH; P < 0.05), physical component score (P < 0.001), mental component score (P < 0.001), and total SF-36 (P < 0.001). LTMEX group also decreased body weight (BW; P < 0.005), waist circumference (WC; P < 0.001), waist-to-hip ratio (WHR; P < 0.001), and systolic blood pressure (SBP; P < 0.001), and increased VO 2 peak (P < 0.001). CO group increased WC (P = 0.012), BMI (P = 0.024), waist-to-hip ratio (WHR; P = 0.003) and SBP (P < 0.001), and decreased vitality (P < 0.001) and MH (P < 0.05). A LTMEX intervention improves physical and mental HRQoL in older adults with T2D, and also anthropometric, hemodynamic profile, and cardiorespiratory fitness.
Solid Propulsion Systems, Subsystems, and Components Service Life Extension
NASA Technical Reports Server (NTRS)
Hundley, Nedra H.; Jones, Connor
2011-01-01
The service life extension of solid propulsion systems, subsystems, and components will be discussed based on the service life extension of the Space Transportation System Reusable Solid Rocket Motor (RSRM) and Booster Separation Motors (BSM). The RSRM is certified for an age life of five years. In the aftermath of the Columbia accident there were a number of motors that were approaching the end of their five year service life certification. The RSRM Project initiated an assessment to determine if the service life of these motors could be extended. With the advent of the Constellation Program, a flight test was proposed that would utilize one of the RSRMs which had been returned from the launch site due to the expiration of its five year service life certification and twelve surplus Chemical Systems Division BSMs which had exceeded their eight year service life. The RSRM age life tracking philosophy which establishes when the clock starts for age life tracking will be described. The role of the following activities in service life extension will be discussed: subscale testing, accelerated aging, dissecting full scale aged hardware, static testing full scale aged motors, data mining industry data, and using the fleet leader approach. The service life certification and extension of the BSMs will also be presented.
Lundqvist, Stefan; Börjesson, Mats; Larsson, Maria E H; Hagberg, Lars; Cider, Åsa
2017-01-01
There is strong evidence that inadequate physical activity (PA) leads to an increased risk of lifestyle-related diseases and premature mortality. Physical activity on prescription (PAP) is a method to increase the level of PA of patients in primary care, but needs further evaluation. The aim of this observational study was to explore the association between PAP-treatment and the PA level of patients with metabolic risk factors and the relationship between changes in the PA level and health outcomes at the 6 month follow-up. This study included 444 patients in primary care, aged 27-85 years (56% females), who were physically inactive with at least one component of metabolic syndrome. The PAP-treatment model included: individualized dialogue concerning PA, prescribed PA, and a structured follow-up. A total of 368 patients (83%) completed the 6 months of follow-up. Of these patients, 73% increased their PA level and 42% moved from an inadequate PA level to sufficient, according to public health recommendations. There were significant improvements (p≤ 0.05) in the following metabolic risk factors: body mass index, waist circumference, systolic blood pressure, fasting plasma glucose, cholesterol, and low density lipoprotein. There were also significant improvements regarding health-related quality of life, assessed by the Short Form 36, in: general health, vitality, social function, mental health, role limitation-physical/emotional, mental component summary, and physical component summary. Regression analysis showed a significant association between changes in the PA level and health outcomes. During the first 6-month period, the caregiver provided PAP support 1-2 times. This study indicates that an individual-based model of PAP-treatment has the potential to change people's PA behavior with improved metabolic risk factors and self-reported quality of life at the 6 month follow-up. Thus, PAP seems to be feasible in a clinical primary care practice, with minimum effort from healthcare professionals.
Dall, Christian H; Gustafsson, Finn; Christensen, Stefan B; Dela, Flemming; Langberg, Henning; Prescott, Eva
2015-08-01
Growing evidence in long-term treatment of heart transplant (HTx) recipients indicates effects of high-intensity interval training (HIIT) on several parameters, including oxygen uptake, vascular function and psychological distress. In this study we compare the effect of HIIT vs continued moderate training (CON) on vascular function, biomarkers and health-related quality of life (HRQoL) in HTx recipients. A randomized, controlled crossover trial of stable HTx recipients >12 months after transplantation was done on patients with 12 weeks of HIIT or 12 weeks of CON, followed by a 5-month washout and crossover. Outcomes included endothelial function, arterial stiffness, biomarkers, HRQoL and markers of anxiety and depression. Sixteen HTx recipients (mean age 52 years, 75% male) completed the study. HIIT increased VO(2peak) more than CON (between-group difference, p < 0.001). The physical component score of the 36-item Short Form (SF-36) was increased significantly in HIIT patients (p = 0.02) and borderline increased in CON patients (p = 0.07), whereas there was no significant effect of exercise on the mental component. Depression score decreased significantly in HIIT patients (p = 0.04) with no change in CON patients (p = 0.75), whereas anxiety score decreased significantly in both HIIT (p < 0.01) and CON (p < 0.05) patients. There were no between-group differences in any of the measures (all p > 0.05). Arterial stiffness and biomarkers were not changed, nor did endothelial function change after HIIT (p = 0.08) or CON (p = 0.68). HIIT and CON are both well tolerated and induce similar improvements in physical components of HRQoL and in markers of anxiety. Effects of either training modality on vascular function and biomarkers could not be confirmed. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.
Börjesson, Mats; Larsson, Maria E. H.; Hagberg, Lars; Cider, Åsa
2017-01-01
There is strong evidence that inadequate physical activity (PA) leads to an increased risk of lifestyle-related diseases and premature mortality. Physical activity on prescription (PAP) is a method to increase the level of PA of patients in primary care, but needs further evaluation. The aim of this observational study was to explore the association between PAP-treatment and the PA level of patients with metabolic risk factors and the relationship between changes in the PA level and health outcomes at the 6 month follow-up. This study included 444 patients in primary care, aged 27–85 years (56% females), who were physically inactive with at least one component of metabolic syndrome. The PAP-treatment model included: individualized dialogue concerning PA, prescribed PA, and a structured follow-up. A total of 368 patients (83%) completed the 6 months of follow-up. Of these patients, 73% increased their PA level and 42% moved from an inadequate PA level to sufficient, according to public health recommendations. There were significant improvements (p≤ 0.05) in the following metabolic risk factors: body mass index, waist circumference, systolic blood pressure, fasting plasma glucose, cholesterol, and low density lipoprotein. There were also significant improvements regarding health-related quality of life, assessed by the Short Form 36, in: general health, vitality, social function, mental health, role limitation-physical/emotional, mental component summary, and physical component summary. Regression analysis showed a significant association between changes in the PA level and health outcomes. During the first 6-month period, the caregiver provided PAP support 1–2 times. This study indicates that an individual-based model of PAP-treatment has the potential to change people’s PA behavior with improved metabolic risk factors and self-reported quality of life at the 6 month follow-up. Thus, PAP seems to be feasible in a clinical primary care practice, with minimum effort from healthcare professionals. PMID:28403151
Lefante, John J; Harmon, Gary N; Ashby, Keith M; Barnard, David; Webber, Larry S
2005-04-01
The utility of the SF-8 for assessing health-related quality of life (HRQL) is demonstrated. Race and gender differences in physical component (PCS) and mental component (MCS) summary scores among participants in the CENLA Medication Access Program (CMAP), along with comparisons to the United States population are made. Age-adjusted multiple linear regression analyses were used to compare 1687 CMAP participants to the US population. Internal race and gender comparisons, adjusting for age and the number of self reported diagnoses, were also obtained. The paired t-test was used to assess 6-month change in PCS and MCS scores for a subset of 342 participants. CMAP participants have PCS and MCS scores that are significantly 10-12 points lower than the US population, indicating lower self-reported HRQL. Females have significantly higher PCS and significantly lower MCS than males. African-Americans have significantly higher MCS than Caucasians. Significant increases in both PCS and MCS were observed for the subset of participants after 6 months of intervention. The expected lower baseline PCS and MCS measures and the expected associations with age and number of diagnoses indicate that the SF-8 survey is an effective tool for measuring the HRQL of participants in this program. Preliminary results indicate significant increases in both PCS and MCS 6 months after intervention.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Marchant, H.J.; Davidson, A.
1992-03-01
Among the most productive region of the Southern Ocean is the marginal ice edge zone that trails the retreating ice edge in spring and early summer. The timing of this near-surface phytoplankton bloom coincides with seasonal stratospheric ozone depletion when UV irradiance is reportedly as high as in mid-summer. Recent investigations indicate that antarctic marine phytoplankton are presently UV stressed. The extent to which increasing UV radiation diminishes the ability of phytoplankton to fix C02 and/or leads to changes in their species composition is equivocal. The colonial stage in the life cycle of the alga Phaeocystis pouchetii is one ofmore » the major components of the bloom. The authors have found that this alga produces extracellular products which are strongly UV-B absorbing. When exposed to increasing levels of UV-B radiation, survival of antarctic colonial Phaeocystis was significantly greater than colonies of this species from temperate waters and of the single-celled stage of its life cycle which produces no UV-B-absorbing compounds. Phaeocystis is apparently a minor dietary component of Antarctic krill, Euphausia superba, and its nutritional value to crustacea is reportedly low. Phytoplankton, principally diatoms, together with fecal pellets and molted exoskeletons of grazers contribute most of the particulate carbon flux from the euphotic zone to deep water.« less
Chou, Frank Huang-Chih; Chen, Pei-Chun; Liu, Renyi; Ho, Chi-Kung; Tsai, Kuan-Yi; Ho, Wen-Wei; Chao, Shin-Shin; Lin, Kung-Shih; Shen, Shih-Pei; Chen, Cheng-Chung
2010-09-01
Immigration to Taiwan is often connected with marriage, resulting in the presence of so-called married immigrants or foreign brides. To compare the quality of life (QOL) and prevalence of depression between female married immigrants and native married women. Trained assistants used the Medical Outcomes Study Short Form-36 (MOS SF-36) and the disaster-related psychological screening test (DRPST) to interview 1,602 married women who were 16-50 years of age. Half (801) of the participants were female immigrants, whilst the remainder comprised the age-matched control group that consisted of 801 native married women. Participants who scored C2 (probable major depressive episode) on the DRPST were assessed according to DSM-IV criteria by a senior psychiatrist. The MOS SF-36 measures QOL and has two dimensions: the physical component summary (PCS) and the mental component summary (MCS). Married immigrants had a lower prevalence (3.5%) of major depressive episodes than native women (8.9%) in Taiwan. Variables such as an increased severity of psychosocial impact were the best predictors of a lower PCS and MCS. Compared to Taiwanese native married women, fewer married immigrants had stressful life events or depression, and they reported higher QOL. After controlling for putative confounding factors, the married immigrants still had better mental QOL and a lower prevalence rate of depression
NASA Astrophysics Data System (ADS)
Grujicic, M.; Sellappan, V.; He, T.; Seyr, Norbert; Obieglo, Andreas; Erdmann, Marc; Holzleitner, Jochen
2009-03-01
Over the last dozen of years, polymer metal hybrid (PMH) technologies have established themselves as viable alternatives for use in light-weight automotive body-in-white bolt-on as well as load-bearing (structural) components. Within the PMH technologies, sheet-metal stamped/formed and thermoplastic injection molding subcomponents are integrated into a singular component/module. Due to attending synergetic effects, the performance of the PMH component typically exceeds that attainable by an alternative single-material technologies. In the present work, a total life cycle (TLC) approach to the selection of metallic and thermoplastic materials (as well as the selection of structural adhesives, where appropriate) is considered. The TLC material selection approach considers the consequences and ramifications of material selection at each major stage of the vehicle manufacturing process chain (press shop, injection molding shop, body shop, paint shop, and assembly), as well as relation to the vehicle performance, durability and the end-of-the-life-of-the-vehicle considerations. The approach is next applied to the case of injection overmolding technology to identify the optimal grade of short glass-fiber reinforced nylon when used in a prototypical PMH load-bearing automotive body-in-white component.
Ogada, Pamella Akoth; Moualeu, Dany Pascal; Poehling, Hans-Michael
2016-01-01
Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant), as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector’s life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV) in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis’ life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector–based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector. PMID:27159134
Ogada, Pamella Akoth; Moualeu, Dany Pascal; Poehling, Hans-Michael
2016-01-01
Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant), as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector's life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV) in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis' life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector-based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector.
User's guide to the stand-damage model: a component of the gypsy moth life system model
J. J. Colbert; George Racin
1995-01-01
The Stand-Damage Model (a component of the Gypsy Moth Life System Model) simulates the growth of a mixed hardwood forest and incorporates the effects of defoliation by gypsy moth or tree harvesting as prescribed by the user. It can be used to assess the damage from expected defoliation, view the differences between various degrees of defoliation, and describe the...
ERIC Educational Resources Information Center
Senol-Durak, Emre; Durak, Mithat
2011-01-01
The factors associated with cognitions about problematic Internet use have been empirically tested in various studies. The aim of the present study was to examine the mediator roles of both life satisfaction and self-esteem between affective components of subjective well-being and cognitions about problematic Internet use. For this purpose, the…
A Distributed Approach to System-Level Prognostics
2012-09-01
the end of (useful) life ( EOL ) and/or the remaining useful life (RUL) of components, subsystems, or systems. The prognostics problem itself can be...system state estimate, computes EOL and/or RUL. In this paper, we focus on a model-based prognostics approach (Orchard & Vachtse- vanos, 2009; Daigle...been focused on individual components, and determining their EOL and RUL, e.g., (Orchard & Vachtsevanos, 2009; Saha & Goebel, 2009; Daigle & Goebel
Relationships between appetite and quality of life in hemodialysis patients.
Zabel, Rachel; Ash, Susan; King, Neil; Juffs, Philip; Bauer, Judith
2012-08-01
The aim of this paper was to investigate the association between appetite and kidney-disease specific quality of life in maintenance hemodialysis patients. Quality of life (QoL) was measured using the kidney disease quality of life survey. Appetite was measured using self-reported categories and a visual analog scale. Other nutritional parameters included Patient-Generated Subjective Global Assessment (PGSGA), dietary intake, body mass index and biochemical markers C-reactive protein and albumin. Even in this well nourished sample (n=62) of hemodialysis patients, PGSGA score (r=-0.629), subjective hunger sensations (r=0.420) and body mass index (r=-0.409) were all significantly associated with the physical health domain of QoL. As self-reported appetite declined, QoL was significantly lower in nine domains which were mostly in the SF36 component and covered social functioning and physical domains. Appetite and other nutritional parameters were not as strongly associated with the Mental Health domain and Kidney Disease Component Summary Domains. Nutritional parameters, especially PGSGA score and appetite, appear to be important components of the physical health domain of QoL. As even small reductions in nutritional status were associated with significantly lower QoL scores, monitoring appetite and nutritional status is an important component of care for hemodialysis patients. Copyright © 2012 Elsevier Ltd. All rights reserved.
Continuum Damage Mechanics Used to Predict the Creep Life of Monolithic Ceramics
NASA Technical Reports Server (NTRS)
Powers, Lynn M.; Jadaan, Osama M.
1998-01-01
Significant improvements in propulsion and power generation for the next century will require revolutionary advances in high-temperature materials and structural design. Advanced ceramics are candidate materials for these elevated temperature applications. High-temperature and long-duration applications of monolithic ceramics can place their failure mode in the creep rupture regime. An analytical methodology in the form of the integrated design program-Ceramics Analysis and Reliability Evaluation of Structures/Creep (CARES/Creep) has been developed by the NASA Lewis Research Center to predict the life of ceramic structural components subjected to creep rupture conditions. This program utilizes commercially available finite element packages and takes into account the transient state of stress and creep strain distributions (stress relaxation as well as the asymmetric response to tension and compression). The creep life of a component is discretized into short time steps, during which the stress distribution is assumed constant. Then, the damage is calculated for each time step on the basis of a modified Monkman-Grant (MMG) creep rupture criterion. The cumulative damage is subsequently calculated as time elapses in a manner similar to Miner's rule for cyclic fatigue loading. Failure is assumed to occur when the normalized cumulative damage at any point in the component reaches unity. The corresponding time is the creep rupture life for that component.
Quality of life following heart valve replacement in the elderly.
Spaziano, Marco; Carrier, Michel; Pellerin, Michel; Choinière, Manon
2010-07-01
The purpose of this investigation was to evaluate both long-term functional status and quality of life (QoL) following valvular replacement surgery in octogenarians. The influence of gender and discharge location was also examined. A total of 133 patients (age range: 80-89 years) who underwent surgical valve replacement between January 2003 and December 2006 was identified. Two questionnaires evaluating QoL (SF-12v2 and MLHFQ), as well as a demographic questionnaire, were sent to these patients. The response rate was 64.4%. Among the participants, the mean NYHA functional class improved from 2.7 to 1.4 after surgery. Men showed results similar to those of the age-matched general Canadian population on the mental and physical component scales of the SF-12v2. The data on women were similar to those of the general population on the physical component scale, but their scores were significantly lower on the mental component scale of the SF-12v2. Further analysis of the results comparing discharge location for each gender revealed that women discharged to a convalescence resource had significantly better QoL scores than those discharged to home with regards to the physical component scale of the SF-12v2, the total score of the MLHFQ, and the physical dimension score of the MLHFQ. Patients aged > or = 80 years benefit from heart valve replacement surgery in terms of both QoL and functional status. Women may be at increased risk of a decline in their emotional well-being and, postoperatively, may benefit more from convalescence than from discharge to home.
Pricing end-of-life components
NASA Astrophysics Data System (ADS)
Vadde, Srikanth; Kamarthi, Sagar V.; Gupta, Surendra M.
2005-11-01
The main objective of a product recovery facility (PRF) is to disassemble end-of-life (EOL) products and sell the reclaimed components for reuse and recovered materials in second-hand markets. Variability in the inflow of EOL products and fluctuation in demand for reusable components contribute to the volatility in inventory levels. To stay profitable the PRFs ought to manage their inventory by regulating the price appropriately to minimize holding costs. This work presents two deterministic pricing models for a PRF bounded by environmental regulations. In the first model, the demand is price dependent and in the second, the demand is both price and time dependent. The models are valid for single component with no inventory replenishment sale during the selling horizon . Numerical examples are presented to illustrate the models.
Li, Dan; Fawaz, Maria V; Morin, Emily E; Ming, Ran; Sviridov, Denis; Tang, Jie; Ackermann, Rose; Olsen, Karl; Remaley, Alan T; Schwendeman, Anna
2018-01-02
Synthetic high density lipoprotein nanoparticles (sHDLs) capable of mobilizing excess cholesterol from atherosclerotic arteries and delivering it to the liver for elimination have been shown to reduce plaque burden in patients. Unfortunately, sHDLs have a narrow therapeutic index and relative to the endogenous HDL shorter circulation half-life. Surface modification with polyethylene glycol (PEG) was investigated for its potential to extend sHDL circulation in vivo. Various amounts (2.5, 5, and 10%) and different chain lengths (2 and 5 kDa) of PEG-modified lipids were incorporated in sHDL's lipid membrane. Incorporating PEG did not reduce the ability of sHDL to facilitate cholesterol efflux, nor did it inhibit cholesterol uptake by the liver cells. By either adding more PEG or using PEG of longer chain lengths, the circulation half-life was extended. Addition of PEG also increased the area under the curve for the phospholipid component of sHDL (p < 0.05), but not for the apolipoprotein A-I peptide component of sHDL, suggesting sHDL is remodeled by endogenous lipoproteins in vivo. The extended phospholipid circulation led to a higher mobilization of plasma free cholesterol, a biomarker for facilitation of reverse cholesterol transport. The area under the cholesterol mobilization increased about 2-4-fold (p < 0.05), with greater increases observed for longer PEG chains and higher molar percentages of incorporated PEGylated lipids. Mobilized cholesterol was associated primarily with the HDL fraction, led to a transient increase in VLDL cholesterol, and returned to baseline 24 h postdose. Overall, PEGylation of sHDL led to beneficial changes in sHDL particle pharmacokinetic and pharmacodynamic behaviors.
The role of iodine in human growth and development.
Zimmermann, Michael B
2011-08-01
Iodine is an essential component of the hormones produced by the thyroid gland. Thyroid hormones, and therefore iodine, are essential for mammalian life. Iodine deficiency is a major public health problem; globally, it is estimated that two billion individuals have an insufficient iodine intake. Although goiter is the most visible sequelae of iodine deficiency, the major impact of hypothyroidism due to iodine deficiency is impaired neurodevelopment, particularly early in life. In the fetal brain, inadequate thyroid hormone impairs myelination, cell migration, differentiation and maturation. Moderate-to-severe iodine deficiency during pregnancy increases rates of spontaneous abortion, reduces birth weight, and increases infant mortality. Offspring of deficient mothers are at high risk for cognitive disability, with cretinism being the most severe manifestation. It remains unclear if development of the offspring is affected by mild maternal iodine deficiency. Moderate-to-severe iodine deficiency during childhood reduces somatic growth. Correction of mild-to-moderate iodine deficiency in primary school aged children improves cognitive and motor function. Iodine prophylaxis of deficient populations with periodic monitoring is an extremely cost effective approach to reduce the substantial adverse effects of iodine deficiency throughout the life cycle. Copyright © 2011 Elsevier Ltd. All rights reserved.
Latent cytokines for targeted therapy of inflammatory disorders.
Mullen, Lisa; Adams, Gill; Layward, Lorna; Vessillier, Sandrine; Annenkov, Alex; Mittal, Gayatri; Rigby, Anne; Sclanders, Michelle; Baker, David; Gould, David; Chernajovsky, Yuti
2014-01-01
The use of cytokines as therapeutic agents is important, given their potent biological effects. However, this very potency, coupled with the pleiotropic nature and short half-life of these molecules, has limited their therapeutic use. Strategies to increase the half-life and to decrease toxicity are necessary to allow effective treatment with these molecules. A number of strategies are used to overcome the natural limitations of cytokines, including PEGylation, encapsulation in liposomes, fusion to targeting peptides or antibodies and latent cytokines. Latent cytokines are engineered using the latency-associated peptide of transforming growth factor-β to produce therapeutic cytokines/peptides that are released only at the site of disease by cleavage with disease-induced matrix metalloproteinases. The principles underlying the latent cytokine technology are described and are compared to other methods of cytokine delivery. The potential of this technology for developing novel therapeutic strategies for the treatment of diseases with an inflammatory-mediated component is discussed. Methods of therapeutic cytokine delivery are addressed. The latent cytokine technology holds significant advantages over other methods of drug delivery by providing simultaneously increased half-life and localised drug delivery without systemic effects. Cytokines that failed clinical trials should be reassessed using this delivery system.
Impact of Life-Cycle Stage and Gender on the Ability to Balance Work and Family Responsibilities.
ERIC Educational Resources Information Center
Higgins, Christopher; And Others
1994-01-01
Examined impact of gender and life-cycle stage on three components of work-family conflict using sample of 3,616 respondents. For men, levels of work-family conflict were moderately lower in each successive life-cycle stage. For women, levels were similar in two early life-cycle stages but were significantly lower in later life-cycle stage.…
Effects and Effectiveness of Life Skills Education for HIV Prevention in Young People
ERIC Educational Resources Information Center
Yankah, Ekua; Aggleton, Peter
2008-01-01
For 20 years, "life skills" education has been advocated as a key component of HIV and AIDS education for young people. But what do terms such as life skills imply, and what evidence is there that a life skills-based approach really works? This article reviews the literature on the effects and effectiveness of life skills-based education for HIV…
Global warming potential of pavements
NASA Astrophysics Data System (ADS)
Santero, Nicholas J.; Horvath, Arpad
2009-09-01
Pavements comprise an essential and vast infrastructure system supporting our transportation network, yet their impact on the environment is largely unquantified. Previous life-cycle assessments have only included a limited number of the applicable life-cycle components in their analysis. This research expands the current view to include eight different components: materials extraction and production, transportation, onsite equipment, traffic delay, carbonation, lighting, albedo, and rolling resistance. Using global warming potential as the environmental indicator, ranges of potential impact for each component are calculated and compared based on the information uncovered in the existing research. The relative impacts between components are found to be orders of magnitude different in some cases. Context-related factors, such as traffic level and location, are also important elements affecting the impacts of a given component. A strategic method for lowering the global warming potential of a pavement is developed based on the concept that environmental performance is improved most effectively by focusing on components with high impact potentials. This system takes advantage of the fact that small changes in high-impact components will have more effect than large changes in low-impact components.
Bagheri, Shirin; Hansson, Emma; Manjer, Jonas; Troëng, Thomas; Brorson, Håkan
2017-01-01
Abstracts Background: Arm lymphedema after breast cancer surgery affects women both from physical and psychological points of view. Lymphedema leads to adipose tissue deposition. Liposuction and controlled compression therapy (CCT) reduces the lymphedema completely. Methods and Results: Sixty female patients with arm lymphedema were followed for a 1-year period after surgery. The 36-item short-form health survey (SF-36) was used to assess health-related quality of life (HRQoL). Patients completed the SF-36 questionnaire before liposuction, and after 1, 3, 6, and 12 months. Preoperative excess arm volume was 1365 ± 73 mL. Complete reduction was achieved after 3 months and was sustained during follow-up. The adipose tissue volume removed at surgery was 1373 ± 56 mL. One month after liposuction, better scores were found in mental health. After 3 months, an increase in physical functioning, bodily pain, and vitality was detected. After 1 year, an increase was also seen for social functioning. The physical component score was higher at 3 months and thereafter, while the mental component score was improved at 3 and 12 months. Compared with SF-36 norm data for the Swedish population, only physical functioning showed lower values than the norm at baseline. After liposuction, general health, bodily pain, vitality, mental health, and social functioning showed higher values at various time points. Conclusions: Liposuction of arm lymphedema in combination with CCT improves patients HRQoL as measured with SF-36. The treatment seems to target and improve both the physical and mental health domains. PMID:28135120
Hoffner, Mattias; Bagheri, Shirin; Hansson, Emma; Manjer, Jonas; Troëng, Thomas; Brorson, Håkan
2017-03-01
Abstracts Background: Arm lymphedema after breast cancer surgery affects women both from physical and psychological points of view. Lymphedema leads to adipose tissue deposition. Liposuction and controlled compression therapy (CCT) reduces the lymphedema completely. Sixty female patients with arm lymphedema were followed for a 1-year period after surgery. The 36-item short-form health survey (SF-36) was used to assess health-related quality of life (HRQoL). Patients completed the SF-36 questionnaire before liposuction, and after 1, 3, 6, and 12 months. Preoperative excess arm volume was 1365 ± 73 mL. Complete reduction was achieved after 3 months and was sustained during follow-up. The adipose tissue volume removed at surgery was 1373 ± 56 mL. One month after liposuction, better scores were found in mental health. After 3 months, an increase in physical functioning, bodily pain, and vitality was detected. After 1 year, an increase was also seen for social functioning. The physical component score was higher at 3 months and thereafter, while the mental component score was improved at 3 and 12 months. Compared with SF-36 norm data for the Swedish population, only physical functioning showed lower values than the norm at baseline. After liposuction, general health, bodily pain, vitality, mental health, and social functioning showed higher values at various time points. Liposuction of arm lymphedema in combination with CCT improves patients HRQoL as measured with SF-36. The treatment seems to target and improve both the physical and mental health domains.
Enhanced CARES Software Enables Improved Ceramic Life Prediction
NASA Technical Reports Server (NTRS)
Janosik, Lesley A.
1997-01-01
The NASA Lewis Research Center has developed award-winning software that enables American industry to establish the reliability and life of brittle material (e.g., ceramic, intermetallic, graphite) structures in a wide variety of 21st century applications. The CARES (Ceramics Analysis and Reliability Evaluation of Structures) series of software is successfully used by numerous engineers in industrial, academic, and government organizations as an essential element of the structural design and material selection processes. The latest version of this software, CARES/Life, provides a general- purpose design tool that predicts the probability of failure of a ceramic component as a function of its time in service. CARES/Life was recently enhanced by adding new modules designed to improve functionality and user-friendliness. In addition, a beta version of the newly-developed CARES/Creep program (for determining the creep life of monolithic ceramic components) has just been released to selected organizations.
Evaluation of corrosion fatigue and life prediction of lower arm for automotive suspension component
NASA Astrophysics Data System (ADS)
Kim, Yong-Sang; Kim, Jung-Gu
2017-01-01
Lower arm is one of the suspension components of automobile. It is suffered from driving vibration and corrosive environment, namely corrosion fatigue. In this study, corrosion fatigue property of lower arm was investigated, and a modified model based on Palmgren-Miner rule was developed to predict the lifetimes of corrosion fatigue. The corrosion fatigue life of lower arm was about 1/6 times shorter than fatigue life. Based on the results of corrosion fatigue tests and meteorological data in Seoul and Halifax, the corrosion fatigue life of lower arm was predicted. The satisfaction of 10-year and 300,000 km warranty was dominated by the climate of automobile driving. This prediction indicates that the weather condition or driving condition influences the life of automotive parts. Therefore, to determine the warranty of automotive parts, the driving condition has to be carefully considered.
Intelligent Life-Extending Controls for Aircraft Engines Studied
NASA Technical Reports Server (NTRS)
Guo, Ten-Huei
2005-01-01
Current aircraft engine controllers are designed and operated to provide desired performance and stability margins. Except for the hard limits for extreme conditions, engine controllers do not usually take engine component life into consideration during the controller design and operation. The end result is that aircraft pilots regularly operate engines under unnecessarily harsh conditions to strive for optimum performance. The NASA Glenn Research Center and its industrial and academic partners have been working together toward an intelligent control concept that will include engine life as part of the controller design criteria. This research includes the study of the relationship between control action and engine component life as well as the design of an intelligent control algorithm to provide proper tradeoffs between performance and engine life. This approach is expected to maintain operating safety while minimizing overall operating costs. In this study, the thermomechanical fatigue (TMF) of a critical component was selected to demonstrate how an intelligent engine control algorithm can significantly extend engine life with only a very small sacrifice in performance. An intelligent engine control scheme based on modifying the high-pressure spool speed (NH) was proposed to reduce TMF damage from ground idle to takeoff. The NH acceleration schedule was optimized to minimize the TMF damage for a given rise-time constraint, which represents the performance requirement. The intelligent engine control scheme was used to simulate a commercial short-haul aircraft engine.
ERIC Educational Resources Information Center
Roodvoets, David L.
2003-01-01
Presents factors to consider when determining roofing life-cycle costs, explaining that costs do not tell the whole story; discussing components that should go into the decision (cost, maintenance, energy use, and environmental costs); and concluding that important elements in reducing life-cycle costs include energy savings through increased…
PRODUCT LIFE-CYCLE ASSESSMENT: INVENTORY GUIDELINES AND PRINCIPLES
The Life Cycle Assessment (LCA) can be used as an objective technical tool to evaluate the environmental consequences of a product, process, or activity holistically, across its entire life cycle. omplete LCA can be viewed as consisting of three complementary components (1) the i...
Keesom, Sarah M; Finton, Caitlyn J; Sell, Gabrielle L; Hurley, Laura M
2017-01-01
Early-life social isolation has profound effects on adult social competence. This is often expressed as increased aggression or inappropriate displays of courtship-related behaviors. The social incompetence exhibited by isolated animals could be in part due to an altered ability to participate in communicatory exchanges. House mice (Mus musculus) present an excellent model for exploring this idea, because social isolation has a well-established influence on their social behavior, and mice engage in communication via multiple sensory modalities. Here, we tested the prediction that social isolation during early life would influence ultrasonic vocalizations (USVs) emitted by adult male mice during same-sex social encounters. Starting at three weeks of age, male mice were housed individually or in social groups of four males for five weeks, after which they were placed in one of three types of paired social encounters. Pair types consisted of: two individually housed males, two socially housed males, or an individually housed and a socially housed male ("mixed" pairs). Vocal behavior (USVs) and non-vocal behaviors were recorded from these 15-minute social interactions. Pairs of mice consisting of at least one individually housed male emitted more and longer USVs, with a greater proportional use of USVs containing frequency jumps and 50-kHz components. Individually housed males in the mixed social pairs exhibited increased levels of mounting behavior towards the socially housed males. Mounting in these pairs was positively correlated with increased number and duration of USVs as well as increased proportional use of spectrally more complex USVs. These findings demonstrate that USVs are part of the suite of social behaviors influenced by early-life social isolation, and suggest that altered vocal communication following isolation reflects reduced social competence.
Finton, Caitlyn J.; Sell, Gabrielle L.; Hurley, Laura M.
2017-01-01
Early-life social isolation has profound effects on adult social competence. This is often expressed as increased aggression or inappropriate displays of courtship-related behaviors. The social incompetence exhibited by isolated animals could be in part due to an altered ability to participate in communicatory exchanges. House mice (Mus musculus) present an excellent model for exploring this idea, because social isolation has a well-established influence on their social behavior, and mice engage in communication via multiple sensory modalities. Here, we tested the prediction that social isolation during early life would influence ultrasonic vocalizations (USVs) emitted by adult male mice during same-sex social encounters. Starting at three weeks of age, male mice were housed individually or in social groups of four males for five weeks, after which they were placed in one of three types of paired social encounters. Pair types consisted of: two individually housed males, two socially housed males, or an individually housed and a socially housed male (“mixed” pairs). Vocal behavior (USVs) and non-vocal behaviors were recorded from these 15-minute social interactions. Pairs of mice consisting of at least one individually housed male emitted more and longer USVs, with a greater proportional use of USVs containing frequency jumps and 50-kHz components. Individually housed males in the mixed social pairs exhibited increased levels of mounting behavior towards the socially housed males. Mounting in these pairs was positively correlated with increased number and duration of USVs as well as increased proportional use of spectrally more complex USVs. These findings demonstrate that USVs are part of the suite of social behaviors influenced by early-life social isolation, and suggest that altered vocal communication following isolation reflects reduced social competence. PMID:28056078