NASA Technical Reports Server (NTRS)
Arya, Vinod K.; Halford, Gary R. (Technical Monitor)
2003-01-01
This manual presents computer programs FLAPS for characterizing and predicting fatigue and creep-fatigue resistance of metallic materials in the high-temperature, long-life regime for isothermal and nonisothermal fatigue. The programs use the Total Strain version of Strainrange Partitioning (TS-SRP), and several other life prediction methods described in this manual. The user should be thoroughly familiar with the TS-SRP and these life prediction methods before attempting to use any of these programs. Improper understanding can lead to incorrect use of the method and erroneous life predictions. An extensive database has also been developed in a parallel effort. The database is probably the largest source of high-temperature, creep-fatigue test data available in the public domain and can be used with other life-prediction methods as well. This users' manual, software, and database are all in the public domain and can be obtained by contacting the author. The Compact Disk (CD) accompanying this manual contains an executable file for the FLAPS program, two datasets required for the example problems in the manual, and the creep-fatigue data in a format compatible with these programs.
Evaluation of methods for determining hardware projected life
NASA Technical Reports Server (NTRS)
1971-01-01
An investigation of existing methods of predicting hardware life is summarized by reviewing programs having long life requirements, current research efforts on long life problems, and technical papers reporting work on life predicting techniques. The results indicate that there are no accurate quantitative means to predict hardware life for system level hardware. The effectiveness of test programs and the cause of hardware failures is considered.
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.
Basis And Application Of The CARES/LIFE Computer Program
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Janosik, Lesley A.; Gyekenyesi, John P.; Powers, Lynn M.
1996-01-01
Report discusses physical and mathematical basis of Ceramics Analysis and Reliability Evaluation of Structures LIFE prediction (CARES/LIFE) computer program, described in "Program for Evaluation of Reliability of Ceramic Parts" (LEW-16018).
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 extending control for rocket engines
NASA Technical Reports Server (NTRS)
Lorenzo, C. F.; Saus, J. R.; Ray, A.; Carpino, M.; Wu, M.-K.
1992-01-01
The concept of life extending control is defined. A brief discussion of current fatigue life prediction methods is given and the need for an alternative life prediction model based on a continuous functional relationship is established. Two approaches to life extending control are considered: (1) the implicit approach which uses cyclic fatigue life prediction as a basis for control design; and (2) the continuous life prediction approach which requires a continuous damage law. Progress on an initial formulation of a continuous (in time) fatigue model is presented. Finally, nonlinear programming is used to develop initial results for life extension for a simplified rocket engine (model).
Thermal barrier coating life prediction model
NASA Technical Reports Server (NTRS)
Pilsner, B. H.; Hillery, R. V.; Mcknight, R. L.; Cook, T. S.; Kim, K. S.; Duderstadt, E. C.
1986-01-01
The objectives of this program are to determine the predominant modes of degradation of a plasma sprayed thermal barrier coating system, and then to develop and verify life prediction models accounting for these degradation modes. The program is divided into two phases, each consisting of several tasks. The work in Phase 1 is aimed at identifying the relative importance of the various failure modes, and developing and verifying life prediction model(s) for the predominant model for a thermal barrier coating system. Two possible predominant failure mechanisms being evaluated are bond coat oxidation and bond coat creep. The work in Phase 2 will develop design-capable, causal, life prediction models for thermomechanical and thermochemical failure modes, and for the exceptional conditions of foreign object damage and erosion.
Effects of surface chemistry on hot corrosion life
NASA Technical Reports Server (NTRS)
Fryxell, R. E.; Leese, G. E.
1985-01-01
This program has its primary objective: the development of hot corrosion life prediction methodology based on a combination of laboratory test data and evaluation of field service turbine components which show evidence of hot corrosion. The laboratory program comprises burner rig testing by TRW. A summary of results is given for two series of burner rig tests. The life prediction methodology parameters to be appraised in a final campaign of burner rig tests are outlined.
Predictive and Treatment Validity of Life Satisfaction and the Quality of Life Inventory
ERIC Educational Resources Information Center
Frisch, Michael B.; Clark, Michelle P.; Rouse, Steven V.; Rudd, M. David; Paweleck, Jennifer K.; Greenstone, Andrew; Kopplin, David A.
2005-01-01
The clinical and positive psychology usefulness of quality of life, well-being, and life satisfaction assessments depends on their ability to predict important outcomes and to detect intervention-related change. These issues were explored in the context of a program of instrument validation for the Quality of Life Inventory (QOLI) involving 3,927…
NASA Technical Reports Server (NTRS)
Mcdermott, P. P.
1980-01-01
The design of an accelerated life test program for electric batteries is discussed. A number of observations and suggestions on the procedures and objectives for conducting an accelerated life test program are presented. Equations based on nonlinear regression analysis for predicting the accelerated life test parameters are discussed.
Validation of Framework Code Approach to a Life Prediction System for Fiber Reinforced Composites
NASA Technical Reports Server (NTRS)
Gravett, Phillip
1997-01-01
The grant was conducted by the MMC Life Prediction Cooperative, an industry/government collaborative team, Ohio Aerospace Institute (OAI) acted as the prime contractor on behalf of the Cooperative for this grant effort. See Figure I for the organization and responsibilities of team members. The technical effort was conducted during the period August 7, 1995 to June 30, 1996 in cooperation with Erwin Zaretsky, the LERC Program Monitor. Phil Gravett of Pratt & Whitney was the principal technical investigator. Table I documents all meeting-related coordination memos during this period. The effort under this grant was closely coordinated with an existing USAF sponsored program focused on putting into practice a life prediction system for turbine engine components made of metal matrix composites (MMC). The overall architecture of the NMC life prediction system was defined in the USAF sponsored program (prior to this grant). The efforts of this grant were focussed on implementing and tailoring of the life prediction system, the framework code within it and the damage modules within it to meet the specific requirements of the Cooperative. T'he tailoring of the life prediction system provides the basis for pervasive and continued use of this capability by the industry/government cooperative. The outputs of this grant are: 1. Definition of the framework code to analysis modules interfaces, 2. Definition of the interface between the materials database and the finite element model, and 3. Definition of the integration of the framework code into an FEM design tool.
NASA Technical Reports Server (NTRS)
Saltsman, James F.
1992-01-01
This manual presents computer programs for characterizing and predicting fatigue and creep-fatigue resistance of metallic materials in the high-temperature, long-life regime for isothermal and nonisothermal fatigue. The programs use the total strain version of Strainrange Partitioning (TS-SRP). An extensive database has also been developed in a parallel effort. This database is probably the largest source of high-temperature, creep-fatigue test data available in the public domain and can be used with other life prediction methods as well. This users manual, software, and database are all in the public domain and are available through COSMIC (382 East Broad Street, Athens, GA 30602; (404) 542-3265, FAX (404) 542-4807). Two disks accompany this manual. The first disk contains the source code, executable files, and sample output from these programs. The second disk contains the creep-fatigue data in a format compatible with these programs.
Life prediction and constitutive models for engine hot section anisotropic materials program
NASA Technical Reports Server (NTRS)
Nissley, D. M.; Meyer, T. G.
1992-01-01
This report presents the results from a 35 month period of a program designed to develop generic constitutive and life prediction approaches and models for nickel-based single crystal gas turbine airfoils. The program is composed of a base program and an optional program. The base program addresses the high temperature coated single crystal regime above the airfoil root platform. The optional program investigates the low temperature uncoated single crystal regime below the airfoil root platform including the notched conditions of the airfoil attachment. Both base and option programs involve experimental and analytical efforts. Results from uniaxial constitutive and fatigue life experiments of coated and uncoated PWA 1480 single crystal material form the basis for the analytical modeling effort. Four single crystal primary orientations were used in the experiments: (001), (011), (111), and (213). Specific secondary orientations were also selected for the notched experiments in the optional program. Constitutive models for an overlay coating and PWA 1480 single crystal material were developed based on isothermal hysteresis loop data and verified using thermomechanical (TMF) hysteresis loop data. A fatigue life approach and life models were selected for TMF crack initiation of coated PWA 1480. An initial life model used to correlate smooth and notched fatigue data obtained in the option program shows promise. Computer software incorporating the overlay coating and PWA 1480 constitutive models was developed.
Life prediction and constitutive models for engine hot section anisotropic materials program
NASA Technical Reports Server (NTRS)
Nissley, D. M.; Meyer, T. G.; Walker, K. P.
1992-01-01
This report presents a summary of results from a 7 year program designed to develop generic constitutive and life prediction approaches and models for nickel-based single crystal gas turbine airfoils. The program was composed of a base program and an optional program. The base program addressed the high temperature coated single crystal regime above the airfoil root platform. The optional program investigated the low temperature uncoated single crystal regime below the airfoil root platform including the notched conditions of the airfoil attachment. Both base and option programs involved experimental and analytical efforts. Results from uniaxial constitutive and fatigue life experiments of coated and uncoated PWA 1480 single crystal material formed the basis for the analytical modeling effort. Four single crystal primary orientations were used in the experiments: group of zone axes (001), group of zone axes (011), group of zone axes (111), and group of zone axes (213). Specific secondary orientations were also selected for the notched experiments in the optional program. Constitutive models for an overlay coating and PWA 1480 single crystal materials were developed based on isothermal hysteresis loop data and verified using thermomechanical (TMF) hysteresis loop data. A fatigue life approach and life models were developed for TMF crack initiation of coated PWA 1480. A life model was developed for smooth and notched fatigue in the option program. Finally, computer software incorporating the overlay coating and PWA 1480 constitutive and life models was developed.
NASA Technical Reports Server (NTRS)
Hirschberg, M. H.
1978-01-01
Twenty laboratories in six countries participated in this program, each testing its own materials of interest under its own laboratory conditions. In this way the results obtained provided validation of the Strainrange Partitioning (SRP) method for a wide range of materials and insured maximum usefulness to each of the participating laboratories. The first, very necessary step in the evaluation of any life prediction approach - assessing the ability of the method to predict life of simple laboratory specimens subjected to complex loading, was thereby taken. The culmination of this program was the Specialists Meeting that was held in Aalborg, Denmark in April of 1978. At that meeting the various investigators shared their findings, thus providing the basis for an in-depth evaluation of the SRP method. While the results were variable from laboratory to laboratory, most investigators agreed that the SRP method was a significant step toward life prediction in the presence of high temperature and cyclic stresses.
Sun Series program for the REEDA System. [predicting orbital lifetime using sunspot values
NASA Technical Reports Server (NTRS)
Shankle, R. W.
1980-01-01
Modifications made to data bases and to four programs in a series of computer programs (Sun Series) which run on the REEDA HP minicomputer system to aid NASA's solar activity predictions used in orbital life time predictions are described. These programs utilize various mathematical smoothing technique and perform statistical and graphical analysis of various solar activity data bases residing on the REEDA System.
Predicting the remaining service life of concrete
DOE Office of Scientific and Technical Information (OSTI.GOV)
Clifton, J.F.
1991-11-01
Nuclear power plants are providing, currently, about 17 percent of the U.S. electricity and many of these plants are approaching their licensed life of 40 years. The U.S. Nuclear Regulatory Commission and the Department of Energy`s Oak Ridge National Laboratory are carrying out a program to develop a methodology for assessing the remaining safe-life of the concrete components and structures in nuclear power plants. This program has the overall objective of identifying potential structural safety issues, as well as acceptance criteria, for use in evaluations of nuclear power plants for continued service. The National Institute of Standards and Technology (NIST)more » is contributing to this program by identifying and analyzing methods for predicting the remaining life of in-service concrete materials. This report examines the basis for predicting the remaining service lives of concrete materials of nuclear power facilities. Methods for predicting the service life of new and in-service concrete materials are analyzed. These methods include (1) estimates based on experience, (2) comparison of performance, (3) accelerated testing, (4) stochastic methods, and (5) mathematical modeling. New approaches for predicting the remaining service lives of concrete materials are proposed and recommendations for their further development given. Degradation processes are discussed based on considerations of their mechanisms, likelihood of occurrence, manifestations, and detection. They include corrosion, sulfate attack, alkali-aggregate reactions, frost attack, leaching, radiation, salt crystallization, and microbiological attack.« less
Creep fatigue life prediction for engine hot section materials (isotropic)
NASA Technical Reports Server (NTRS)
Moreno, V.
1983-01-01
The Hot Section Technology (HOST) program, creep fatigue life prediction for engine hot section materials (isotropic), is reviewed. The program is aimed at improving the high temperature crack initiation life prediction technology for gas turbine hot section components. Significant results include: (1) cast B1900 and wrought IN 718 selected as the base and alternative materials respectively; (2) fatigue test specimens indicated that measurable surface cracks appear early in the specimen lives, i.e., 15% of total life at 871 C and 50% of life at 538 c; (3) observed crack initiation sites are all surface initiated and are associated with either grain boundary carbides or local porosity, transgrannular cracking is observed at the initiation site for all conditions tested; and (4) an initial evaluation of two life prediction models, representative of macroscopic (Coffin-Mason) and more microscopic (damage rate) approaches, was conducted using limited data generated at 871 C and 538 C. It is found that the microscopic approach provides a more accurate regression of the data used to determine crack initiation model constants, but overpredicts the effect of strain rate on crack initiation life for the conditions tested.
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.
Predicted effect of dynamic load on pitting fatigue life for low-contact-ratio spur gears
NASA Technical Reports Server (NTRS)
Lewicki, David G.
1986-01-01
How dynamic load affects the surface pitting fatigue life of external spur gears was predicted by using the NASA computer program TELSGE. Parametric studies were performed over a range of various gear parameters modeling low-contact-ratio involute spur gears. In general, gear life predictions based on dynamic loads differed significantly from those based on static loads, with the predictions being strongly influenced by the maximum dynamic load during contact. Gear mesh operating speed strongly affected predicted dynamic load and life. Meshes operating at a resonant speed or one-half the resonant speed had significantly shorter lives. Dynamic life factors for gear surface pitting fatigue were developed on the basis of the parametric studies. In general, meshes with higher contact ratios had higher dynamic life factors than meshes with lower contact ratios. A design chart was developed for hand calculations of dynamic life factors.
Impact of predictive model-directed end-of-life counseling for Medicare beneficiaries.
Hamlet, Karen S; Hobgood, Adam; Hamar, Guy Brent; Dobbs, Angela C; Rula, Elizabeth Y; Pope, James E
2010-05-01
To validate a predictive model for identifying Medicare beneficiaries who need end-of-life care planning and to determine the impact on cost and hospice care of a telephonic counseling program utilizing this predictive model in 2 Medicare Health Support (MHS) pilots. Secondary analysis of data from 2 MHS pilot programs that used a randomized controlled design. A predictive model was developed using intervention group data (N = 43,497) to identify individuals at greatest risk of death. Model output guided delivery of a telephonic intervention designed to support educated end-of-life decisions and improve end-of-life provisions. Control group participants received usual care. As a primary outcome, Medicare costs in the last 6 months of life were compared between intervention group decedents (n = 3112) and control group decedents (n = 1630). Hospice admission rates and duration of hospice care were compared as secondary measures. The predictive model was highly accurate, and more than 80% of intervention group decedents were contacted during the 12 months before death. Average Medicare costs were $1913 lower for intervention group decedents compared with control group decedents in the last 6 months of life (P = .05), for a total savings of $5.95 million. There were no significant changes in hospice admissions or mean duration of hospice care. Telephonic end-of-life counseling provided as an ancillary Medicare service, guided by a predictive model, can reach a majority of individuals needing support and can reduce costs by facilitating voluntary election of less intensive care.
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)
NASA Technical Reports Server (NTRS)
Saltsman, J. F.
1994-01-01
TS-SRP/PACK is a set of computer programs for characterizing and predicting fatigue and creep-fatigue resistance of metallic materials in the high-temperature, long-life regime for isothermal and nonisothermal fatigue. The programs use the total strain version of the Strainrange Partitioning (TS-SRP). The user should be thoroughly familiar with the TS-SRP method before attempting to use any of these programs. The document for this program includes a theory manual as well as a detailed user's manual with a tutorial to guide the user in the proper use of TS-SRP. An extensive database has also been developed in a parallel effort. This database is an excellent source of high-temperature, creep-fatigue test data and can be used with other life-prediction methods as well. Five programs are included in TS-SRP/PACK along with the alloy database. The TABLE program is used to print the datasets, which are in NAMELIST format, in a reader friendly format. INDATA is used to create new datasets or add to existing ones. The FAIL program is used to characterize the failure behavior of an alloy as given by the constants in the strainrange-life relations used by the total strain version of SRP (TS-SRP) and the inelastic strainrange-based version of SRP. The program FLOW is used to characterize the flow behavior (the constitutive response) of an alloy as given by the constants in the flow equations used by TS-SRP. Finally, LIFE is used to predict the life of a specified cycle, using the constants characterizing failure and flow behavior determined by FAIL and FLOW. LIFE is written in interpretive BASIC to avoid compiling and linking every time the equation constants are changed. Four out of five programs in this package are written in FORTRAN 77 for IBM PC series and compatible computers running MS-DOS and are designed to read data using the NAMELIST format statement. The fifth is written in BASIC version 3.0 for IBM PC series and compatible computers running MS-DOS version 3.10. The executables require at least 239K of memory and DOS 3.1 or higher. To compile the source, a Lahey FORTRAN compiler is required. Source code modifications will be necessary if the compiler to be used does not support NAMELIST input. Probably the easiest revision to make is to use a list-directed READ statement. The standard distribution medium for this program is a set of two 5.25 inch 360K MS-DOS format diskettes. The contents of the diskettes are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. TS-SRP/PACK was developed in 1992.
2017-10-01
AWARD NUMBER: W81XWH-16-1-0629 TITLE: Understanding, Predicting, and Preventing Life-Changing and Life-Threatening Health Changes among Aging...Threatening Health Changes among Aging Veterans and Civilians with Spinal Cord Injury 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-16-1-0629 5c. PROGRAM... health conditions, such as pressure ulcers and infections, that occur either in isolation or in combination. Our purpose is to identify how multiple
Musekamp, Gunda; Bengel, Jürgen; Schuler, Michael; Faller, Hermann
2016-08-01
Self-management programs aim to improve patients' skills to manage their chronic condition in everyday life. Improvement in self-management is assumed to bring about improvements in more distal outcomes, such as quality of life. This study aimed to test the hypothesis that changes in self-reported self-management skills observed after participation in self-management programs predict changes in both quality of life and depressive symptoms three months later. Using latent change modeling, the relationship between changes in latent variables over three time points (start and end of rehabilitation, after three months) was analysed. The sample comprised 580 patients with different chronic conditions treated in inpatient rehabilitation clinics. The influence of additional predictor variables (age, sex, perceived social support) and type of disorder as a moderator variable was also tested. Changes in self-reported self-management skills after rehabilitation predicted changes in both quality of life and depressive symptoms at the end of rehabilitation and the 3 months follow-up. These relationships remained significant after the inclusion of other predictor variables and were similar across disorders. The findings provide support for the hypothesis that improvements in proximal outcomes of self-management programs may foster improvements in distal outcomes. Further studies should investigate treatment mechanisms. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Stuck in the Middle: Doctoral Education Ranking and Career Outcomes for Life Scientists
ERIC Educational Resources Information Center
Smith-Doerr, Laurel
2006-01-01
Why do some Ph.D.'s languish in positions with little authority, and what does educational background have to do with it? Hypotheses predicted that life scientists with Ph.D.'s from elite programs would be the most likely, those from middle-ranked programs the next most likely, and those from lower ranked programs the least likely to achieve…
International Space Station Bacteria Filter Element Post-Flight Testing and Service Life Prediction
NASA Technical Reports Server (NTRS)
Perry, J. L.; von Jouanne, R. G.; Turner, E. H.
2003-01-01
The International Space Station uses high efficiency particulate air (HEPA) filters to remove particulate matter from the cabin atmosphere. Known as Bacteria Filter Elements (BFEs), there are 13 elements deployed on board the ISS's U.S. Segment. The pre-flight service life prediction of 1 year for the BFEs is based upon performance engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS Program resources. Thus testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are discussed. Recommendations for realizing significant savings to the ISS Program are presented.
Composite structural materials
NASA Technical Reports Server (NTRS)
Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.
1979-01-01
Technology utilization of fiber reinforced composite materials is discussed in the areas of physical properties, and life prediction. Programs related to the Composite Aircraft Program are described in detail.
Positive life events predict salivary cortisol in pregnant women.
Pluess, Michael; Wurmser, Harald; Buske-Kirschbaum, Angelika; Papousek, Mechthild; Pirke, Karl-Martin; Hellhammer, Dirk; Bolten, Margarete
2012-08-01
Maternal stress during pregnancy has been repeatedly associated with problematic child development. According to the fetal programming hypothesis adverse experiences during pregnancy increase maternal cortisol, which is then assumed to exert a negative effect on fetal development. Recent studies in non-pregnant women report significant associations between positive emotionality and low cortisol levels. We tested in a sample of 60 pregnant women whether both negative and positive life events independently predicted third-trimester baseline awakening cortisol levels. While the effect of negative life events proved unrelated positive life events significantly predicted lower cortisol levels. These findings suggest that positive experiences are of relevance regarding maternal morning cortisol levels in pregnancy reflecting a resource with potentially beneficial effects for the mother and the developing fetus. It might be promising for psychological intervention programs to focus on increasing positive experiences of the expecting mother rather than exclusively trying to reduce maternal stress during pregnancy. Copyright © 2012 Elsevier Ltd. All rights reserved.
Condition Assessment and End-of-Life Prediction System for Electric Machines and Their Loads
NASA Technical Reports Server (NTRS)
Parlos, Alexander G.; Toliyat, Hamid A.
2005-01-01
An end-of-life prediction system developed for electric machines and their loads could be used in integrated vehicle health monitoring at NASA and in other government agencies. This system will provide on-line, real-time condition assessment and end-of-life prediction of electric machines (e.g., motors, generators) and/or their loads of mechanically coupled machinery (e.g., pumps, fans, compressors, turbines, conveyor belts, magnetic levitation trains, and others). In long-duration space flight, the ability to predict the lifetime of machinery could spell the difference between mission success or failure. Therefore, the system described here may be of inestimable value to the U.S. space program. The system will provide continuous monitoring for on-line condition assessment and end-of-life prediction as opposed to the current off-line diagnoses.
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.
2002-01-01
Brittle materials are being used, or considered, for a wide variety of high tech applications that operate in harsh environments, including static and rotating turbine parts. thermal protection systems, dental prosthetics, fuel cells, oxygen transport membranes, radomes, and MEMS. Designing components to sustain repeated load without fracturing while using the minimum amount of material requires the use of a probabilistic design methodology. The CARES/Life code provides a general-purpose analysis tool that predicts the probability of failure of a ceramic component as a function of its time in service. For this presentation an interview of the CARES/Life program will be provided. Emphasis will be placed on describing the latest enhancements to the code for reliability analysis with time varying loads and temperatures (fully transient reliability analysis). Also, early efforts in investigating the validity of using Weibull statistics, the basis of the CARES/Life program, to characterize the strength of MEMS structures will be described as as well as the version of CARES/Life for MEMS (CARES/MEMS) being prepared which incorporates single crystal and edge flaw reliability analysis capability. It is hoped this talk will open a dialog for potential collaboration in the area of MEMS testing and life prediction.
Thermal barrier coating life prediction model development, phase 2
NASA Technical Reports Server (NTRS)
Meier, Susan Manning; Sheffler, Keith D.; Nissley, David M.
1991-01-01
The objective of this program was to generate a life prediction model for electron-beam-physical vapor deposited (EB-PVD) zirconia thermal barrier coating (TBC) on gas turbine engine components. Specific activities involved in development of the EB-PVD life prediction model included measurement of EB-PVD ceramic physical and mechanical properties and adherence strength, measurement of the thermally grown oxide (TGO) growth kinetics, generation of quantitative cyclic thermal spallation life data, and development of a spallation life prediction model. Life data useful for model development was obtained by exposing instrumented, EB-PVD ceramic coated cylindrical specimens in a jet fueled burner rig. Monotonic compression and tensile mechanical tests and physical property tests were conducted to obtain the EB-PVD ceramic behavior required for burner rig specimen analysis. As part of that effort, a nonlinear constitutive model was developed for the EB-PVD ceramic. Spallation failure of the EB-PVD TBC system consistently occurred at the TGO-metal interface. Calculated out-of-plane stresses were a small fraction of that required to statically fail the TGO. Thus, EB-PVD spallation was attributed to the interfacial cracking caused by in-plane TGO strains. Since TGO mechanical properties were not measured in this program, calculation of the burner rig specimen TGO in-plane strains was performed by using alumina properties. A life model based on maximum in-plane TGO tensile mechanical strain and TGO thickness correlated the burner rig specimen EB-PVD ceramic spallation lives within a factor of about plus or minus 2X.
NASA Technical Reports Server (NTRS)
Wu, X. R.; Newman, J. C.; Zhao, W.; Swain, M. H.; Ding, C. F.; Phillips, E. P.
1998-01-01
The small crack effect was investigated in two high-strength aluminium alloys: 7075-T6 bare and LC9cs clad alloy. Both experimental and analytical investigations were conducted to study crack initiation and growth of small cracks. In the experimental program, fatigue tests, small crack and large crack tests A,ere conducted under constant amplitude and Mini-TWIST spectrum loading conditions. A pronounced small crack effect was observed in both materials, especially for the negative stress ratios. For all loading conditions, most of the fatigue life of the SENT specimens was shown to be crack propagation from initial material defects or from the cladding layer. In the analysis program, three-dimensional finite element and A weight function methods were used to determine stress intensity factors and to develop SIF equations for surface and corner cracks at the notch in the SENT specimens. A plastisity-induced crack-closure model was used to correlate small and large crack data, and to make fatigue life predictions, Predicted crack-growth rates and fatigue lives agreed well with experiments. A total fatigue life prediction method for the aluminum alloys was developed and demonstrated using the crack-closure model.
Toward more environmentally resistant gas turbines: Progress in NASA-Lewis programs
NASA Technical Reports Server (NTRS)
Lowell, C. E.; Grisaffe, S. J.; Levine, S. R.
1976-01-01
A wide range of programs are being conducted for improving the environmental resistance to oxidation and hot corrosion of gas turbine and power system materials. They range from fundamental efforts to delineate attack mechanisms, allow attack modeling and permit life prediction, to more applied efforts to develop potentially more resistant alloys and coatings. Oxidation life prediction efforts have resulted in a computer program which provides an initial method for predicting long time metal loss using short time oxidation data by means of a paralinear attack model. Efforts in alloy development have centered on oxide-dispersion strengthened alloys based on the Ni-Cr-Al system. Compositions have been identified which are compromises between oxidation and thermal fatigue resistance. Fundamental studies of hot corrosion mechanisms include thermodynamic studies of sodium sulfate formation during turbine combustion. Information concerning species formed during the vaporization of Na2SO4 has been developed using high temperature mass spectrometry.
Shuttle environmental and thermal control/life support system computer program, supplement 1
NASA Technical Reports Server (NTRS)
Ayotte, W. J.
1975-01-01
The computer programs developed to simulate the RSECS (Representative Shuttle Environmental Control System) were described. These programs were prepared to provide pretest predictions, post-test analysis and real time problem analysis for RSECS test planning and evaluation.
Life modeling of thermal barrier coatings for aircraft gas turbine engines
NASA Technical Reports Server (NTRS)
Miller, R. A.
1989-01-01
Thermal barrier coating life models developed under the NASA Lewis Research Center's Hot Section Technology (HOST) Program are summarized. An initial laboratory model and three design-capable models are discussed. Current understanding of coating failure mechanisms are also summarized. The materials and structural aspects of thermal barrier coatings have been successfully integrated under the HOST program to produce models which may now or in the near future be used in design. Efforts on this program continue at Pratt and Whitney Aircraft where their model is being extended to the life prediction of physical vapor deposited thermal barrier coatings.
A life prediction model for laminated composite structural components
NASA Technical Reports Server (NTRS)
Allen, David H.
1990-01-01
A life prediction methodology for laminated continuous fiber composites subjected to fatigue loading conditions was developed. A summary is presented of research completed. A phenomenological damage evolution law was formulated for matrix cracking which is independent of stacking sequence. Mechanistic and physical support was developed for the phenomenological evolution law proposed above. The damage evolution law proposed above was implemented to a finite element computer program. And preliminary predictions were obtained for a structural component undergoing fatigue loading induced damage.
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.
Disease Management: The Need for a Focus on Broader Self-Management Abilities and Quality of Life
Nieboer, Anna Petra
2015-01-01
Abstract The study objective was to investigate long-term effects of disease management programs (DMPs) on (1) health behaviors (smoking, physical exercise); (2) self-management abilities (self-efficacy, investment behavior, initiative taking); and (3) physical and mental quality of life among chronically ill patients. The study also examined whether (changes in) health behaviors and self-management abilities predicted quality of life. Questionnaires were sent to all 5076 patients participating in 18 Dutch DMPs in 2010 (T0; 2676 [53%] respondents). Two years later (T1), questionnaires were sent to 4350 patients still participating in DMPs (1722 [40%] respondents). Structured interviews were held with the 18 DMP project leaders. DMP implementation improved patients' health behavior and physical quality of life, but mental quality of life and self-management abilities declined over time. Changes in patients' investment behavior predicted physical quality of life at T1 (P<.001); physical activity, investment behavior (both P<.05), and self-efficacy (P<.01) at T0, and changes in self-efficacy and investment behavior (both P<.001) predicted patients' mental quality of life at T1. The long-term benefits of these DMPs include successful improvement of chronically ill patients' health behaviors and physical quality of life. However, these programs were not able to improve or maintain broader self-management abilities or mental quality of life, highlighting the need to focus on these abilities and overall quality of life. As coproducers of care, patients should be stimulated and enabled to manage their health and quality of life. (Population Health Management 2015;18:246–255) PMID:25607246
Disease Management: The Need for a Focus on Broader Self-Management Abilities and Quality of Life.
Cramm, Jane Murray; Nieboer, Anna Petra
2015-08-01
The study objective was to investigate long-term effects of disease management programs (DMPs) on (1) health behaviors (smoking, physical exercise); (2) self-management abilities (self-efficacy, investment behavior, initiative taking); and (3) physical and mental quality of life among chronically ill patients. The study also examined whether (changes in) health behaviors and self-management abilities predicted quality of life. Questionnaires were sent to all 5076 patients participating in 18 Dutch DMPs in 2010 (T0; 2676 [53%] respondents). Two years later (T1), questionnaires were sent to 4350 patients still participating in DMPs (1722 [40%] respondents). Structured interviews were held with the 18 DMP project leaders. DMP implementation improved patients' health behavior and physical quality of life, but mental quality of life and self-management abilities declined over time. Changes in patients' investment behavior predicted physical quality of life at T1 (P<.001); physical activity, investment behavior (both P<.05), and self-efficacy (P<.01) at T0, and changes in self-efficacy and investment behavior (both P<.001) predicted patients' mental quality of life at T1. The long-term benefits of these DMPs include successful improvement of chronically ill patients' health behaviors and physical quality of life. However, these programs were not able to improve or maintain broader self-management abilities or mental quality of life, highlighting the need to focus on these abilities and overall quality of life. As coproducers of care, patients should be stimulated and enabled to manage their health and quality of life.
NASA Technical Reports Server (NTRS)
Nesbitt, James A.
2001-01-01
A finite-difference computer program (COSIM) has been written which models the one-dimensional, diffusional transport associated with high-temperature oxidation and interdiffusion of overlay-coated substrates. The program predicts concentration profiles for up to three elements in the coating and substrate after various oxidation exposures. Surface recession due to solute loss is also predicted. Ternary cross terms and concentration-dependent diffusion coefficients are taken into account. The program also incorporates a previously-developed oxide growth and spalling model to simulate either isothermal or cyclic oxidation exposures. In addition to predicting concentration profiles after various oxidation exposures, the program can also be used to predict coating life based on a concentration dependent failure criterion (e.g., surface solute content drops to 2%). The computer code is written in FORTRAN and employs numerous subroutines to make the program flexible and easily modifiable to other coating oxidation problems.
Accelerated battery-life testing - A concept
NASA Technical Reports Server (NTRS)
Mccallum, J.; Thomas, R. E.
1971-01-01
Test program, employing empirical, statistical and physical methods, determines service life and failure probabilities of electrochemical cells and batteries, and is applicable to testing mechanical, electrical, and chemical devices. Data obtained aids long-term performance prediction of battery or cell.
Creep-fatigue life prediction for engine hot section materials (isotropic)
NASA Technical Reports Server (NTRS)
Moreno, V.
1982-01-01
The objectives of this program are the investigation of fundamental approaches to high temperature crack initiation life prediction, identification of specific modeling strategies and the development of specific models for component relevant loading conditions. A survey of the hot section material/coating systems used throughout the gas turbine industry is included. Two material/coating systems will be identified for the program. The material/coating system designated as the base system shall be used throughout Tasks 1-12. The alternate material/coating system will be used only in Task 12 for further evaluation of the models developed on the base material. In Task II, candidate life prediction approaches will be screened based on a set of criteria that includes experience of the approaches within the literature, correlation with isothermal data generated on the base material, and judgements relative to the applicability of the approach for the complex cycles to be considered in the option program. The two most promising approaches will be identified. Task 3 further evaluates the best approach using additional base material fatigue testing including verification tests. Task 4 consists of technical, schedular, financial and all other reporting requirements in accordance with the Reports of Work clause.
Strainrange partitioning behavior of the nickel-base superalloys, Rene' 80 and in 100
NASA Technical Reports Server (NTRS)
Halford, G. R.; Nachtigall, A. J.
1978-01-01
A study was made to assess the ability of the method of Strainrange Partitioning (SRP) to both correlate and predict high-temperature, low cycle fatigue lives of nickel base superalloys for gas turbine applications. The partitioned strainrange versus life relationships for uncoated Rene' 80 and cast IN 100 were also determined from the ductility normalized-Strainrange Partitioning equations. These were used to predict the cyclic lives of the baseline tests. The life predictability of the method was verified for cast IN 100 by applying the baseline results to the cyclic life prediction of a series of complex strain cycling tests with multiple hold periods at constant strain. It was concluded that the method of SRP can correlate and predict the cyclic lives of laboratory specimens of the nickel base superalloys evaluated in this program.
Thermal barrier coating life-prediction model development
NASA Technical Reports Server (NTRS)
Strangman, T. E.; Neumann, J.; Liu, A.
1986-01-01
The program focuses on predicting the lives of two types of strain-tolerant and oxidation-resistant thermal barrier coating (TBC) systems that are produced by commercial coating suppliers to the gas turbine industry. The plasma-sprayed TBC system, composed of a low-pressure plasma-spray (LPPS) or an argon shrouded plasma-spray (ASPS) applied oxidation resistant NiCrAlY or (CoNiCrAlY) bond coating and an air-plasma-sprayed yttria partially stabilized zirconia insulative layer, is applied by both Chromalloy, Klock, and Union Carbide. The second type of TBS is applied by the electron beam-physical vapor deposition (EB-PVD) process by Temescal. The second year of the program was focused on specimen procurement, TMC system characterization, nondestructive evaluation methods, life prediction model development, and TFE731 engine testing of thermal barrier coated blades. Materials testing is approaching completion. Thermomechanical characterization of the TBC systems, with toughness, and spalling strain tests, was completed. Thermochemical testing is approximately two-thirds complete. Preliminary materials life models for the bond coating oxidation and zirconia sintering failure modes were developed. Integration of these life models with airfoil component analysis methods is in progress. Testing of high pressure turbine blades coated with the program TBS systems is in progress in a TFE731 turbofan engine. Eddy current technology feasibility was established with respect to nondestructively measuring zirconia layer thickness of a TBC system.
Poonamallee, Latha; Harrington, Alex M.; Nagpal, Manisha; Musial, Alec
2018-01-01
Emotional intelligence is established to predict success in leadership effectiveness in various contexts and has been linked to personality factors. This paper introduces Dharma Life Program, a novel approach to improving emotional intelligence by targeting maladaptive personality traits and triggering neuroplasticity through the use of a smart-phone application and mentoring. The program uses neuroplasticity to enable users to create a more adaptive application of their maladaptive traits, thus improving their emotional intelligence. In this study 26 participants underwent the Dharma Life Program in a leadership development setting. We assessed their emotional and social intelligence before and after the Dharma Life Program intervention using the Emotional and Social Competency Inventory (ESCI). The study found a significant improvement in the lowest three competencies and a significant improvement in almost all domains for the entire sample. Our findings suggest that the completion of the Dharma Life Program has a significant positive effect on Emotional and Social Competency scores and offers a new avenue for improving emotional intelligence competencies. PMID:29527182
Poonamallee, Latha; Harrington, Alex M; Nagpal, Manisha; Musial, Alec
2018-01-01
Emotional intelligence is established to predict success in leadership effectiveness in various contexts and has been linked to personality factors. This paper introduces Dharma Life Program, a novel approach to improving emotional intelligence by targeting maladaptive personality traits and triggering neuroplasticity through the use of a smart-phone application and mentoring. The program uses neuroplasticity to enable users to create a more adaptive application of their maladaptive traits, thus improving their emotional intelligence. In this study 26 participants underwent the Dharma Life Program in a leadership development setting. We assessed their emotional and social intelligence before and after the Dharma Life Program intervention using the Emotional and Social Competency Inventory (ESCI). The study found a significant improvement in the lowest three competencies and a significant improvement in almost all domains for the entire sample. Our findings suggest that the completion of the Dharma Life Program has a significant positive effect on Emotional and Social Competency scores and offers a new avenue for improving emotional intelligence competencies.
MDOT Pavement Management System : Prediction Models and Feedback System
DOT National Transportation Integrated Search
2000-10-01
As a primary component of a Pavement Management System (PMS), prediction models are crucial for one or more of the following analyses: : maintenance planning, budgeting, life-cycle analysis, multi-year optimization of maintenance works program, and a...
NASA Technical Reports Server (NTRS)
Stephenson, Frank W., Jr.
1988-01-01
The NASA Earth-to-Orbit (ETO) Propulsion Technology Program is dedicated to advancing rocket engine technologies for the development of fully reusable engine systems that will enable space transportation systems to achieve low cost, routine access to space. The program addresses technology advancements in the areas of engine life extension/prediction, performance enhancements, reduced ground operations costs, and in-flight fault tolerant engine operations. The primary objective is to acquire increased knowledge and understanding of rocket engine chemical and physical processes in order to evolve more realistic analytical simulations of engine internal environments, to derive more accurate predictions of steady and unsteady loads, and using improved structural analyses, to more accurately predict component life and performance, and finally to identify and verify more durable advanced design concepts. In addition, efforts were focused on engine diagnostic needs and advances that would allow integrated health monitoring systems to be developed for enhanced maintainability, automated servicing, inspection, and checkout, and ultimately, in-flight fault tolerant engine operations.
Life Prediction Issues in Thermal/Environmental Barrier Coatings in Ceramic Matrix Composites
NASA Technical Reports Server (NTRS)
Shah, Ashwin R.; Brewer, David N.; Murthy, Pappu L. N.
2001-01-01
Issues and design requirements for the environmental barrier coating (EBC)/thermal barrier coating (TBC) life that are general and those specific to the NASA Ultra-Efficient Engine Technology (UEET) development program have been described. The current state and trend of the research, methods in vogue related to the failure analysis, and long-term behavior and life prediction of EBCITBC systems are reported. Also, the perceived failure mechanisms, variables, and related uncertainties governing the EBCITBC system life are summarized. A combined heat transfer and structural analysis approach based on the oxidation kinetics using the Arrhenius theory is proposed to develop a life prediction model for the EBC/TBC systems. Stochastic process-based reliability approach that includes the physical variables such as gas pressure, temperature, velocity, moisture content, crack density, oxygen content, etc., is suggested. Benefits of the reliability-based approach are also discussed in the report.
Prediction of atmospheric degradation data for POPs by gene expression programming.
Luan, F; Si, H Z; Liu, H T; Wen, Y Y; Zhang, X Y
2008-01-01
Quantitative structure-activity relationship models for the prediction of the mean and the maximum atmospheric degradation half-life values of persistent organic pollutants were developed based on the linear heuristic method (HM) and non-linear gene expression programming (GEP). Molecular descriptors, calculated from the structures alone, were used to represent the characteristics of the compounds. HM was used both to pre-select the whole descriptor sets and to build the linear model. GEP yielded satisfactory prediction results: the square of the correlation coefficient r(2) was 0.80 and 0.81 for the mean and maximum half-life values of the test set, and the root mean square errors were 0.448 and 0.426, respectively. The results of this work indicate that the GEP is a very promising tool for non-linear approximations.
NASA Technical Reports Server (NTRS)
Jadaan, Osama M.; Powers, Lynn M.; Gyekenyesi, John P.
1998-01-01
High temperature and long duration applications of monolithic ceramics can place their failure mode in the creep rupture regime. A previous model advanced by the authors described a methodology by which the creep rupture life of a loaded component can be predicted. That model was based on the life fraction damage accumulation rule in association with the modified Monkman-Grant creep ripture criterion However, that model did not take into account the deteriorating state of the material due to creep damage (e.g., cavitation) as time elapsed. In addition, the material creep parameters used in that life prediction methodology, were based on uniaxial creep curves displaying primary and secondary creep behavior, with no tertiary regime. The objective of this paper is to present a creep life prediction methodology based on a modified form of the Kachanov-Rabotnov continuum damage mechanics (CDM) theory. In this theory, the uniaxial creep rate is described in terms of stress, temperature, time, and the current state of material damage. This scalar damage state parameter is basically an abstract measure of the current state of material damage due to creep deformation. The damage rate is assumed to vary with stress, temperature, time, and the current state of damage itself. Multiaxial creep and creep rupture formulations of the CDM approach are presented in this paper. Parameter estimation methodologies based on nonlinear regression analysis are also described for both, isothermal constant stress states and anisothermal variable stress conditions This creep life prediction methodology was preliminarily added to the integrated design code CARES/Creep (Ceramics Analysis and Reliability Evaluation of Structures/Creep), which is a postprocessor program to commercially available finite element analysis (FEA) packages. Two examples, showing comparisons between experimental and predicted creep lives of ceramic specimens, are used to demonstrate the viability of this methodology and the CARES/Creep program.
NASA Technical Reports Server (NTRS)
Vonhermann, Pieter; Pintz, Adam
1994-01-01
This manual describes the use of the ANSCARES program to prepare a neutral file of FEM stress results taken from ANSYS Release 5.0, in the format needed by CARES/LIFE ceramics reliability program. It is intended for use by experienced users of ANSYS and CARES. Knowledge of compiling and linking FORTRAN programs is also required. Maximum use is made of existing routines (from other CARES interface programs and ANSYS routines) to extract the finite element results and prepare the neutral file for input to the reliability analysis. FORTRAN and machine language routines as described are used to read the ANSYS results file. Sub-element stresses are computed and written to a neutral file using FORTRAN subroutines which are nearly identical to those used in the NASCARES (MSC/NASTRAN to CARES) interface.
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.
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.
Thermal barrier coating life prediction model development
NASA Technical Reports Server (NTRS)
Demasi, J. T.; Sheffler, K. D.
1986-01-01
The objective of this program is to establish a methodology to predict Thermal Barrier Coating (TBC) life on gas turbine engine components. The approach involves experimental life measurement coupled with analytical modeling of relevant degradation modes. The coating being studied is a flight qualified two layer system, designated PWA 264, consisting of a nominal ten mil layer of seven percent yttria partially stabilized zirconia plasma deposited over a nominal five mil layer of low pressure plasma deposited NiCoCrAlY. Thermal barrier coating degradation modes being investigated include: thermomechanical fatigue, oxidation, erosion, hot corrosion, and foreign object damage.
Life Prediction of Fretting Fatigue with Advanced Surface Treatments (Preprint)
2006-05-01
surfaces and not the fretting pads. The chosen coatings included DLC, Ni-B, Molybdenum, and Nitride. These 4 coatings, their application to the titanium ...Article Preprint 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 4 . TITLE AND SUBTITLE LIFE PREDICTION OF FRETTING FATIGUE WITH ADVANCED SURFACE...TREATMENTS (PREPRINT) 5c. PROGRAM ELEMENT NUMBER N/A 5d. PROJECT NUMBER M02R 5e. TASK NUMBER 30 6 . AUTHOR(S) Patrick J. Golden and Michael
Sonar Transducer Reliability Improvement Program (STRIP).
1981-04-01
CERAMICS. ... .......................... 31 10. STANDARDIZED TEST PROCEDURE ........ .................... ... 35 11. ACCELERATED LIFE TEST...components, and piece-parts that will meet specified requirements in the operational environment during the entire useful life of the transducer. Standards...C.I. Bohmaun F-3 Reliability & Life Prediction TRI R.I. Smith Specification ,F-4 TR-122 FM4 & Improvements NRL-USRD R.W. Timm 1-5 Metal Matrix
Evaluation program for secondary spacecraft cells: Cycle life test
NASA Technical Reports Server (NTRS)
Harkness, J. D.
1979-01-01
The service life and storage stability for several storage batteries were determined. The batteries included silver-zinc batteries, nickel-cadmium batteries, and silver-cadmium batteries. The cell performance characteristics and limitations are to be used by spacecraft power systems planners and designers. A statistical analysis of the life cycle prediction and cause of failure versus test conditions is presented.
Smeltzer, Suzanne C; Sharts-Hopko, Nancy C; Cantrell, Mary Ann; Heverly, Mary Ann; Wise, Nancy; Jenkinson, Amanda
Support for research strongly predicts doctoral program faculty members' research productivity. Although academic administrators affect such support, their views of faculty members' use of support are unknown. We examined academic administrators' perceptions of institutional support and their perceptions of the effects of teaching doctoral students on faculty members' scholarship productivity and work-life balance. An online survey was completed by a random sample of 180 deans/directors of schools of nursing and doctoral programs directors. Data were analyzed with descriptive statistics, chi-square analysis, and analysis of variance. Deans and doctoral program directors viewed the level of productivity of program faculty as high to moderately high and unchanged since faculty started teaching doctoral students. Deans perceived better administrative research supports, productivity, and work-life balance of doctoral program faculty than did program directors. Findings indicate the need for greater administrative support for scholarship and mentoring given the changes in the composition of doctoral program faculty. Copyright © 2017 Elsevier Inc. All rights reserved.
Preschool Life Skills: Recent Advancements and Future Directions
ERIC Educational Resources Information Center
Fahmie, Tara A.; Luczynski, Kevin C.
2018-01-01
Over the past decade, researchers have replicated and extended research on the preschool life skills (PLS) program developed by Hanley, Heal, Tiger, and Ingvarsson (2007). This review summarizes recent research with respect to maximizing skill acquisition, improving generality, evaluating feasibility and acceptability, and testing predictions of…
Predicting the Reliability of Ceramics Under Transient Loads and Temperatures With CARES/Life
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Jadaan, Osama M.; Palfi, Tamas; Baker, Eric H.
2003-01-01
A methodology is shown for predicting the time-dependent reliability of ceramic components against catastrophic rupture when subjected to transient thermomechanical loads (including cyclic loads). The methodology takes into account the changes in material response that can occur with temperature or time (i.e., changing fatigue and Weibull parameters with temperature or time). This capability has been added to the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code. The code has been modified to have the ability to interface with commercially available finite element analysis (FEA) codes executed for transient load histories. Examples are provided to demonstrate the features of the methodology as implemented in the CARES/Life program.
Small-crack effects in high-strength aluminum alloys
NASA Technical Reports Server (NTRS)
Newman, J. C., Jr.; Wu, X. R.; Venneri, S. L.; Li, C. G.
1994-01-01
The National Aeronautics and Space Administration and the Chinese Aeronautical Establishment participated in a Fatigue and Fracture Mechanics Cooperative Program. The program objectives were to identify and characterize crack initiation and growth of small cracks (10 microns to 2 mm long) in commonly used US and PRC aluminum alloys, to improve fracture mechanics analyses of surface- and corner-crack configurations, and to develop improved life-prediction methods. Fatigue and small-crack tests were performed on single-edgenotch tension (SENT) specimens and large-crack tests were conducted on center-crack tension specimens for constant-amplitude (stress ratios of -1, 0, and 0.5) and Mini-TWIST spectrum loading. The plastic replica method was used to monitor the initiation and growth of small fatigue cracks at the semicircular notch. Crack growth results from each laboratory on 7075-T6 bare and LC9cs clad aluminum alloys agreed well and showed that fatigue life was mostly crack propagation from a material defect (inclusion particles or void) or from the cladding layer. Finite-element and weight-function methods were used to determine stress intensity factors for surface and corner cracks in the SENT specimens. Equations were then developed and used in a crack growth and crack-closure model to correlate small- and large-crack data and to make life predictions for various load histories. The cooperative program produced useful experimental data and efficient analysis methods for improving life predictions. The results should ultimately improve aircraft structural reliability and safety.
Thermal barrier coating life-prediction model development. Annual report no. 2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Strangman, T. E.; Neumann, J.; Liu, A.
1986-10-01
The program focuses on predicting the lives of two types of strain-tolerant and oxidation-resistant thermal barrier coating (TBC) systems that are produced by commercial coating suppliers to the gas turbine industry. The plasma-sprayed TBC system, composed of a low-pressure plasma-spray (LPPS) or an argon shrouded plasma-spray (ASPS) applied oxidation resistant NiCrAlY or (CoNiCrAlY) bond coating and an air-plasma-sprayed yttria partially stabilized zirconia insulative layer, is applied by both Chromalloy, Klock, and Union Carbide. The second type of TBS is applied by the electron beam-physical vapor deposition (EB-PVD) process by Temescal. The second year of the program was focused on specimenmore » procurement, TMC system characterization, nondestructive evaluation methods, life prediction model development, and TFE731 engine testing of thermal barrier coated blades. Materials testing is approaching completion. Thermomechanical characterization of the TBC systems, with toughness, and spalling strain tests, was completed. Thermochemical testing is approximately two-thirds complete. Preliminary materials life models for the bond coating oxidation and zirconia sintering failure modes were developed. Integration of these life models with airfoil component analysis methods is in progress. Testing of high pressure turbine blades coated with the program TBS systems is in progress in a TFE731 turbofan engine. Eddy current technology feasibility was established with respect to nondestructively measuring zirconia layer thickness of a TBC system.« less
Bellows flow-induced vibrations
NASA Technical Reports Server (NTRS)
Tygielski, P. J.; Smyly, H. M.; Gerlach, C. R.
1983-01-01
The bellows flow excitation mechanism and results of comprehensive test program are summarized. The analytical model for predicting bellows flow induced stress is refined. The model includes the effects of an upstream elbow, arbitrary geometry, and multiple piles. A refined computer code for predicting flow induced stress is described which allows life prediction if a material S-N diagram is available.
Development of Probabilistic Life Prediction Methodologies and Testing Strategies for MEMS and CMC's
NASA Technical Reports Server (NTRS)
Jadaan, Osama
2003-01-01
This effort is to investigate probabilistic life prediction methodologies for ceramic matrix composites and MicroElectroMechanical Systems (MEMS) and to analyze designs that determine stochastic properties of MEMS. For CMC's this includes a brief literature survey regarding lifing methodologies. Also of interest for MEMS is the design of a proper test for the Weibull size effect in thin film (bulge test) specimens. The Weibull size effect is a consequence of a stochastic strength response predicted from the Weibull distribution. Confirming that MEMS strength is controlled by the Weibull distribution will enable the development of a probabilistic design methodology for MEMS - similar to the GRC developed CARES/Life program for bulk ceramics. A main objective of this effort is to further develop and verify the ability of the Ceramics Analysis and Reliability Evaluation of Structures/Life (CARES/Life) code to predict the time-dependent reliability of MEMS structures subjected to multiple transient loads. A second set of objectives is to determine the applicability/suitability of the CARES/Life methodology for CMC analysis, what changes would be needed to the methodology and software, and if feasible, run a demonstration problem. Also important is an evaluation of CARES/Life coupled to the ANSYS Probabilistic Design System (PDS) and the potential of coupling transient reliability analysis to the ANSYS PDS.
Design of Oil-Lubricated Machine for Life and Reliability
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin V.
2007-01-01
In the post-World War II era, the major technology drivers for improving the life, reliability, and performance of rolling-element bearings and gears have been the jet engine and the helicopter. By the late 1950s, most of the materials used for bearings and gears in the aerospace industry had been introduced into use. By the early 1960s, the life of most steels was increased over that experienced in the early 1940s, primarily by the introduction of vacuum degassing and vacuum melting processes in the late 1950s. The development of elastohydrodynamic (EHD) theory showed that most rolling bearings and gears have a thin film separating the contacting bodies during motion and it is that film which affects their lives. Computer programs modeling bearing and gear dynamics that incorporate probabilistic life prediction methods and EHD theory enable optimization of rotating machinery based on life and reliability. With improved manufacturing and processing, the potential improvement in bearing and gear life can be as much as 80 times that attainable in the early 1950s. The work presented summarizes the use of laboratory fatigue data for bearings and gears coupled with probabilistic life prediction and EHD theories to predict the life and reliability of a commercial turboprop gearbox. The resulting predictions are compared with field data.
Thermal barrier coating life prediction model development, phase 1
NASA Technical Reports Server (NTRS)
Demasi, Jeanine T.; Ortiz, Milton
1989-01-01
The objective of this program was to establish a methodology to predict thermal barrier coating (TBC) life on gas turbine engine components. The approach involved experimental life measurement coupled with analytical modeling of relevant degradation modes. Evaluation of experimental and flight service components indicate the predominant failure mode to be thermomechanical spallation of the ceramic coating layer resulting from propagation of a dominant near interface crack. Examination of fractionally exposed specimens indicated that dominant crack formation results from progressive structural damage in the form of subcritical microcrack link-up. Tests conducted to isolate important life drivers have shown MCrAlY oxidation to significantly affect the rate of damage accumulation. Mechanical property testing has shown the plasma deposited ceramic to exhibit a non-linear stress-strain response, creep and fatigue. The fatigue based life prediction model developed accounts for the unusual ceramic behavior and also incorporates an experimentally determined oxide rate model. The model predicts the growth of this oxide scale to influence the intensity of the mechanic driving force, resulting from cyclic strains and stresses caused by thermally induced and externally imposed mechanical loads.
Quantification of Forecasting and Change-Point Detection Methods for Predictive Maintenance
2015-08-19
industries to manage the service life of equipment, and also to detect precursors to the failure of components found in nuclear power plants, wind turbines ...detection methods for predictive maintenance 5a. CONTRACT NUMBER FA2386-14-1-4096 5b. GRANT NUMBER Grant 14IOA015 AOARD-144096 5c. PROGRAM ELEMENT...sensitive to changes related to abnormality. 15. SUBJECT TERMS predictive maintenance , predictive maintenance , forecasting 16
NASA Technical Reports Server (NTRS)
Hannum, N. P.; Nielson, C. E.
1983-01-01
Data are presented for two different experimental programs which were conducted to investigate the characteristics of a hybrid (hydrostatic/ball) bearing operating in liquid hydrogen. The same bearing design was used in both programs. Analytical predictions were made of the bearing characteristics and are compared with the experimental results when possible. The first program used a bearing tester to determine the steady state, transient, and cyclic life characteristics of the bearing over a wide range of operating conditions. The second program demonstrated the feasibility of applying hybrid bearings to an actual high speed turbopump by retrofitting and then testing an existing liquid hydrogen turbopump with the bearings.
Composite structural materials
NASA Technical Reports Server (NTRS)
Ansell, G. S.; Wiberley, S. E.
1978-01-01
The purpose of the RPI composites program is to develop advanced technology in the areas of physical properties, structural concepts and analysis, manufacturing, reliability and life prediction. Concommitant goals are to educate engineers to design and use composite materials as normal or conventional materials. A multifaceted program was instituted to achieve these objectives.
Creep fatigue life prediction for engine hot section materials (isotropic)
NASA Technical Reports Server (NTRS)
Moreno, Vito; Nissley, David; Lin, Li-Sen Jim
1985-01-01
The first two years of a two-phase program aimed at improving the high temperature crack initiation life prediction technology for gas turbine hot section components are discussed. In Phase 1 (baseline) effort, low cycle fatigue (LCF) models, using a data base generated for a cast nickel base gas turbine hot section alloy (B1900+Hf), were evaluated for their ability to predict the crack initiation life for relevant creep-fatigue loading conditions and to define data required for determination of model constants. The variables included strain range and rate, mean strain, strain hold times and temperature. None of the models predicted all of the life trends within reasonable data requirements. A Cycle Damage Accumulation (CDA) was therefore developed which follows an exhaustion of material ductility approach. Material ductility is estimated based on observed similarities of deformation structure between fatigue, tensile and creep tests. The cycle damage function is based on total strain range, maximum stress and stress amplitude and includes both time independent and time dependent components. The CDA model accurately predicts all of the trends in creep-fatigue life with loading conditions. In addition, all of the CDA model constants are determinable from rapid cycle, fully reversed fatigue tests and monotonic tensile and/or creep data.
Weber, Christian; Neeser, Kurt
2006-08-01
Diabetes is an increasing health problem, but efforts to handle this pandemic by disease management programs (DMP) have shown conflicting results. Our hypothesis is that, in addition to a program's content and setting, the choice of the right patients is crucial to a program's efficacy and effectiveness. We used individualized predictive disease modeling (IPDM) on a cohort of 918 patients with type 2 diabetes to identify those patients with the greatest potential to benefit from inclusion in a DMP. A portion of the patients (4.7%) did not have even a theoretical potential for an increase in life expectancy and would therefore be unlikely to benefit from a DMP. Approximately 16.1% had an increase in life expectancy of less than half a year. Stratification of the entire cohort by surrogate parameters like preventable 10-year costs or gain in life expectancy was much more effective than stratification by classical clinical parameters such as high HbA1c level. Preventable costs increased up to 50.6% (or 1,010 per patient (1 = US dollars 1.28), p < 0.01) and life expectancy increased up to 54.8% (or 2.3 years, p < 0.01). IPDM is a valuable strategy to identify those patients with the greatest potential to avoid diabetes-related complications and thus can improve the overall effectiveness and efficacy of DMPs for diabetes mellitus.
NASA Technical Reports Server (NTRS)
Herman, Daniel A.
2010-01-01
The NASA s Evolutionary Xenon Thruster (NEXT) program is tasked with significantly improving and extending the capabilities of current state-of-the-art NSTAR thruster. The service life capability of the NEXT ion thruster is being assessed by thruster wear test and life-modeling of critical thruster components, such as the ion optics and cathodes. The NEXT Long-Duration Test (LDT) was initiated to validate and qualify the NEXT thruster propellant throughput capability. The NEXT thruster completed the primary goal of the LDT; namely to demonstrate the project qualification throughput of 450 kg by the end of calendar year 2009. The NEXT LDT has demonstrated 28,500 hr of operation and processed 466 kg of xenon throughput--more than double the throughput demonstrated by the NSTAR flight-spare. Thruster performance changes have been consistent with a priori predictions. Thruster erosion has been minimal and consistent with the thruster service life assessment, which predicts the first failure mode at greater than 750 kg throughput. The life-limiting failure mode for NEXT is predicted to be loss of structural integrity of the accelerator grid due to erosion by charge-exchange ions.
Elevated temperature biaxial fatigue
NASA Technical Reports Server (NTRS)
Jordan, E. H.
1983-01-01
Biaxial fatigue is often encountered in the complex thermo-mechanical loadings present in gas turbine engines. Engine strain histories can involve non-constant temperature, mean stress, creep, environmental effects, both isotropic and anisotropic materials and non-proportional loading. Life prediction for the general case involving all the above factors is not a practicable research project. The current research program is limited to isothermal fatigue at room temperature and 1200 F of Hastalloy-X for both proportional and non-proportional loading. An improved method for predicting the fatigue life and deformation response under biaxial cycle loading is sought.
Environment assisted degradation mechanisms in advanced light metals
NASA Technical Reports Server (NTRS)
Gangloff, Richard P.; Stoner, Glenn E.; Swanson, Robert E.
1988-01-01
The general goals of the research program are to characterize alloy behavior quantitatively and to develop predictive mechanisms for environmental failure modes. Successes in this regard will provide the basis for metallurgical optimization of alloy performance, for chemical control of aggressive environments, and for engineering life prediction with damage tolerance and long term reliability.
Dispositional hope and life satisfaction among older adults attending lifelong learning programs.
Oliver, A; Tomás, J M; Montoro-Rodriguez, J
2017-09-01
The aim of this study is to explore the indirect effects of dispositional hope in the life satisfaction of older adults attending a lifelong learning program at the University of Valencia, Spain. We examine the mediating impact of dispositional hope regarding its ability to impact life satisfaction while considering affective and confidant social support, perceived health and leisure activities, consciousness and spirituality as predictors. Analysis were based on survey data (response rate 77.4%) provided by 737 adults 55 years old or more (Mean age=65.41, SD=6.60; 69% woman). A structural model with latent variables was specified and estimated in Mplus. The results show the ability of just a few variables to sum up a reasonable model to apply to successful aging population. All these variables are correlated and significantly predict hope with the exception of health. The model additionally includes significant positive indirect effects from spirituality, affective support and consciousness on satisfaction. The model has a good fit in terms of both the measurement and structural model. Regarding predictive power, these comprehensive four main areas of successful aging account for 42% of hope and finally for one third of the life satisfaction variance. Results support the mediating role of dispositional hope on the life satisfaction among older adults attending lifelong learning programs. These findings also support the MacArthur model of successful aging adapted to older adults with high levels of functional, social and cognitive ability. Dispositional hope, perceived health, and social support were the strongest predictors of satisfaction with life. Copyright © 2017 Elsevier B.V. All rights reserved.
Lithium-Ion Batteries for Aerospace Applications
NASA Technical Reports Server (NTRS)
Surampudi, S.; Halpert, G.; Marsh, R. A.; James, R.
1999-01-01
This presentation reviews: (1) the goals and objectives, (2) the NASA and Airforce requirements, (3) the potential near term missions, (4) management approach, (5) the technical approach and (6) the program road map. The objectives of the program include: (1) develop high specific energy and long life lithium ion cells and smart batteries for aerospace and defense applications, (2) establish domestic production sources, and to demonstrate technological readiness for various missions. The management approach is to encourage the teaming of universities, R&D organizations, and battery manufacturing companies, to build on existing commercial and government technology, and to develop two sources for manufacturing cells and batteries. The technological approach includes: (1) develop advanced electrode materials and electrolytes to achieve improved low temperature performance and long cycle life, (2) optimize cell design to improve specific energy, cycle life and safety, (3) establish manufacturing processes to ensure predictable performance, (4) establish manufacturing processes to ensure predictable performance, (5) develop aerospace lithium ion cells in various AH sizes and voltages, (6) develop electronics for smart battery management, (7) develop a performance database required for various applications, and (8) demonstrate technology readiness for the various missions. Charts which review the requirements for the Li-ion battery development program are presented.
Characterization of Damage Accumulation in a C/SiC Composite at Elevated Temperatures
NASA Technical Reports Server (NTRS)
Telesman, Jack; Verrilli, Mike; Ghosn, Louis; Kantzos, Pete
1997-01-01
This research is part of a program aimed to evaluate and demonstrate the ability of candidate CMC materials for a variety of applications in reusable launch vehicles. The life and durability of these materials in rocket and engine applications are of major concern and there is a need to develop and validate life prediction methodology. In this study, material characterization and mechanical testing was performed in order to identify the failure modes, degradation mechanisms, and progression of damage in a C/SiC composite at elevated temperatures. The motivation for this work is to provide the relevant damage information that will form the basis for the development of a physically based life prediction methodology.
Solar array electrical performance assessment for Space Station Freedom
NASA Technical Reports Server (NTRS)
Smith, Bryan K.; Brisco, Holly
1993-01-01
Electrical power for Space Station Freedom will be generated by large Photovoltaic arrays with a beginning of life power requirement of 30.8 kW per array. The solar arrays will operate in a Low Earth Orbit (LEO) over a design life of fifteen years. This paper provides an analysis of the predicted solar array electrical performance over the design life and presents a summary of supporting analysis and test data for the assigned model parameters and performance loss factors. Each model parameter and loss factor is assessed based upon program requirements, component analysis, and test data to date. A description of the LMSC performance model, future test plans, and predicted performance ranges are also given.
Solar array electrical performance assessment for Space Station Freedom
NASA Technical Reports Server (NTRS)
Smith, Bryan K.; Brisco, Holly
1993-01-01
Electrical power for Space Station Freedom will be generated by large photovoltaic arrays with a beginning of life power requirement of 30.8 kW per array. The solar arrays will operate in a Low Earth Orbit (LEO) over a design life of fifteen years. This paper provides an analysis of the predicted solar array electrical performance over the design life and presents a summary of supporting analysis and test data for the assigned model parameters and performance loss factors. Each model parameter and loss factor is assessed based upon program requirements, component analysis and test data to date. A description of the LMSC performance model future test plans and predicted performance ranges are also given.
Damage Precursor Investigation of Fiber-Reinforced Composite Materials Under Fatigue Loads
2013-09-01
19.21, 215713. Thostenson, E. T.; Chou, T.‐W. Carbon Nanotube Networks: Sensing of Distributed Strain and Damage for Life Prediction and Self Healing ...composite structural life and the goal of the proposed research program to develop self -responsive engineered composites. Over 80%‒90% of the life of a...composite material. It is also envisaged to investigate and develop self -responsive engineered composite materials that provide an accurate health
File Usage Analysis and Resource Usage Prediction: a Measurement-Based Study. Ph.D. Thesis
NASA Technical Reports Server (NTRS)
Devarakonda, Murthy V.-S.
1987-01-01
A probabilistic scheme was developed to predict process resource usage in UNIX. Given the identity of the program being run, the scheme predicts CPU time, file I/O, and memory requirements of a process at the beginning of its life. The scheme uses a state-transition model of the program's resource usage in its past executions for prediction. The states of the model are the resource regions obtained from an off-line cluster analysis of processes run on the system. The proposed method is shown to work on data collected from a VAX 11/780 running 4.3 BSD UNIX. The results show that the predicted values correlate well with the actual. The coefficient of correlation between the predicted and actual values of CPU time is 0.84. Errors in prediction are mostly small. Some 82% of errors in CPU time prediction are less than 0.5 standard deviations of process CPU time.
Predictability of process resource usage - A measurement-based study on UNIX
NASA Technical Reports Server (NTRS)
Devarakonda, Murthy V.; Iyer, Ravishankar K.
1989-01-01
A probabilistic scheme is developed to predict process resource usage in UNIX. Given the identity of the program being run, the scheme predicts CPU time, file I/O, and memory requirements of a process at the beginning of its life. The scheme uses a state-transition model of the program's resource usage in its past executions for prediction. The states of the model are the resource regions obtained from an off-line cluster analysis of processes run on the system. The proposed method is shown to work on data collected from a VAX 11/780 running 4.3 BSD UNIX. The results show that the predicted values correlate well with the actual. The correlation coefficient betweeen the predicted and actual values of CPU time is 0.84. Errors in prediction are mostly small. Some 82 percent of errors in CPU time prediction are less than 0.5 standard deviations of process CPU time.
Predictability of process resource usage: A measurement-based study of UNIX
NASA Technical Reports Server (NTRS)
Devarakonda, Murthy V.; Iyer, Ravishankar K.
1987-01-01
A probabilistic scheme is developed to predict process resource usage in UNIX. Given the identity of the program being run, the scheme predicts CPU time, file I/O, and memory requirements of a process at the beginning of its life. The scheme uses a state-transition model of the program's resource usage in its past executions for prediction. The states of the model are the resource regions obtained from an off-line cluster analysis of processes run on the system. The proposed method is shown to work on data collected from a VAX 11/780 running 4.3 BSD UNIX. The results show that the predicted values correlate well with the actual. The correlation coefficient between the predicted and actual values of CPU time is 0.84. Errors in prediction are mostly small. Some 82% of errors in CPU time prediction are less than 0.5 standard deviations of process CPU time.
NASA Technical Reports Server (NTRS)
Clark, E. C.
1975-01-01
Thruster valve assemblies (T/VA's) were subjected to the development test program for the combined JPL Low-Cost Standardized Spacecraft Equipment (LCSSE) and Mariner Jupiter/Saturn '77 spacecraft (MJS) programs. The development test program was designed to achieve the following program goals: (1) demonstrate T/VA design compliance with JPL Specifications, (2) to conduct a complete performance Cf map of the T/VA over the full operating range of environment, (3) demonstrate T/VA life capability and characteristics of life margin for steady-state limit cycle and momentum wheel desaturation duty cycles, (4) verification of structural design capability, and (5) generate a computerized performance model capable of predicting T/VA operation over pressures ranging from 420 to 70 psia, propellant temperatures ranging from 140 F to 40 F, pulse widths of 0.008 to steady-state operation with unlimited duty cycle capability, and finally predict the transient performance associated with reactor heatup during any given duty cycle, start temperature, feed pressure, and propellant temperature conditions.
Fatigue life prediction of liquid rocket engine combustor with subscale test verification
NASA Astrophysics Data System (ADS)
Sung, In-Kyung
Reusable rocket systems such as the Space Shuttle introduced a new era in propulsion system design for economic feasibility. Practical reusable systems require an order of magnitude increase in life. To achieve this improved methods are needed to assess failure mechanisms and to predict life cycles of rocket combustor. A general goal of the research was to demonstrate the use of subscale rocket combustor prototype in a cost-effective test program. Life limiting factors and metal behaviors under repeated loads were surveyed and reviewed. The life prediction theories are presented, with an emphasis on studies that used subscale test hardware for model validation. From this review, low cycle fatigue (LCF) and creep-fatigue interaction (ratcheting) were identified as the main life limiting factors of the combustor. Several life prediction methods such as conventional and advanced viscoplastic models were used to predict life cycle due to low cycle thermal stress, transient effects, and creep rupture damage. Creep-fatigue interaction and cyclic hardening were also investigated. A prediction method based on 2D beam theory was modified using 3D plate deformation theory to provide an extended prediction method. For experimental validation two small scale annular plug nozzle thrusters were designed, built and tested. The test article was composed of a water-cooled liner, plug annular nozzle and 200 psia precombustor that used decomposed hydrogen peroxide as the oxidizer and JP-8 as the fuel. The first combustor was tested cyclically at the Advanced Propellants and Combustion Laboratory at Purdue University. Testing was stopped after 140 cycles due to an unpredicted failure mechanism due to an increasing hot spot in the location where failure was predicted. A second combustor was designed to avoid the previous failure, however, it was over pressurized and deformed beyond repair during cold-flow test. The test results are discussed and compared to the analytical and numerical predictions. A detailed comparison was not performed, however, due to the lack of test data resulting from a failure of the test article. Some theoretical and experimental aspects such as fin effect and round corner were found to reduce the discrepancy between prediction and test results.
Deterministic Multiaxial Creep and Creep Rupture Enhancements for CARES/Creep Integrated Design Code
NASA Technical Reports Server (NTRS)
Jadaan, Osama M.
1998-01-01
High temperature and long duration applications of monolithic ceramics can place their failure mode in the creep rupture regime. A previous model advanced by the authors described a methodology by which the creep rupture life of a loaded component can be predicted. That model was based on the life fraction damage accumulation rule in association with the modified Monkman-Grant creep rupture criterion. However, that model did not take into account the deteriorating state of the material due to creep damage (e.g., cavitation) as time elapsed. In addition, the material creep parameters used in that life prediction methodology, were based on uniaxial creep curves displaying primary and secondary creep behavior, with no tertiary regime. The objective of this paper is to present a creep life prediction methodology based on a modified form of the Kachanov-Rabotnov continuum damage mechanics (CDM) theory. In this theory, the uniaxial creep rate is described in terms of sum, temperature, time, and the current state of material damage. This scalar damage state parameter is basically an abstract measure of the current state of material damage due to creep deformation. The damage rate is assumed to vary with stress, temperature, time, and the current state of damage itself. Multiaxial creep and creep rupture formulations of the CDM approach are presented in this paper. Parameter estimation methodologies based on nonlinear regression analysis are also described for both, isothermal constant stress states and anisothermal variable stress conditions This creep life prediction methodology was preliminarily added to the integrated design code CARES/Creep (Ceramics Analysis and Reliability Evaluation of Structures/Creep), which is a postprocessor program to commercially available finite element analysis (FEA) packages. Two examples, showing comparisons between experimental and predicted creep lives of ceramic specimens, are used to demonstrate the viability of Ns methodology and the CARES/Creep program.
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.
Matthieu, Monica M.; Lawrence, Karen A.; Robertson-Blackmore, Emma
2017-01-01
Volunteering as a health promotion intervention, improves physical health, mental health, and social outcomes particularly in older adults, yet limited research exists for veterans. We conducted a preliminary study to explore whether volunteering impacts a variety of biopsychosocial outcomes, including symptoms of post-traumatic stress disorder (PTSD) and depression, among returning military veterans from Iraq and Afghanistan. A survey enrolling a prospective cohort of United States (U.S.) veterans who served in the military after 11 September 2001 and who participated in a national civic service program was conducted. A total of 346 veterans completed standardized health, mental health, and psychosocial self-report measures before and after the program. Statistically significant differences were detected in overall health rating, level of emotional difficulty, PTSD and depression symptoms, purpose in life, self-efficacy, social isolation, and the perceived availability of social support at program completion. Screening positive for probable PTSD predicted improved perceived self-efficacy while probable depression predicted a decrease in loneliness, an increase in purpose in life, and an increase in perceived social support, at program completion. Volunteering was associated with significant improvements in health, mental health and social outcomes in returning veterans. PMID:28039802
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.
Structural analysis of cylindrical thrust chambers, volume 3
NASA Technical Reports Server (NTRS)
Pearson, M. L.
1981-01-01
A system of three computer programs is described for use in conjunction with the BOPAGE finite element program. The programs are demonstrated by analyzing cumulative plastic deformation in a regeneratively cooled rocket thrust chamber. The codes provide the capability to predict geometric and material nonlinear behavior of cyclically loaded structures without performing a cycle-by-cycle analysis over the life of the structure. The program set consists of a BOPACE restart tape reader routine, and extrapolation program and a plot package.
Creep fatigue life prediction for engine hot section materials (ISOTROPIC)
NASA Technical Reports Server (NTRS)
Nelson, R. S.; Schoendorf, J. F.; Lin, L. S.
1986-01-01
The specific activities summarized include: verification experiments (base program); thermomechanical cycling model; multiaxial stress state model; cumulative loading model; screening of potential environmental and protective coating models; and environmental attack model.
Life Sciences Implications of Lunar Surface Operations
NASA Technical Reports Server (NTRS)
Chappell, Steven P.; Norcross, Jason R.; Abercromby, Andrew F.; Gernhardt, Michael L.
2010-01-01
The purpose of this report is to document preliminary, predicted, life sciences implications of expected operational concepts for lunar surface extravehicular activity (EVA). Algorithms developed through simulation and testing in lunar analog environments were used to predict crew metabolic rates and ground reaction forces experienced during lunar EVA. Subsequently, the total metabolic energy consumption, the daily bone load stimulus, total oxygen needed, and other variables were calculated and provided to Human Research Program and Exploration Systems Mission Directorate stakeholders. To provide context to the modeling, the report includes an overview of some scenarios that have been considered. Concise descriptions of the analog testing and development of the algorithms are also provided. This document may be updated to remain current with evolving lunar or other planetary surface operations, assumptions and concepts, and to provide additional data and analyses collected during the ongoing analog research program.
The Need for Technology Maturity of Any Advanced Capability to Achieve Better Life Cycle Cost (LCC)
NASA Technical Reports Server (NTRS)
Robinson, John W.; Levack, Daniel J. H.; Rhodes, Russel E.; Chen, Timothy T.
2009-01-01
Programs such as space transportation systems are developed and deployed only rarely, and they have long development schedules and large development and life cycle costs (LCC). They have not historically had their LCC predicted well and have only had an effort to control the DDT&E phase of the programs. One of the factors driving the predictability, and thus control, of the LCC of a program is the maturity of the technologies incorporated in the program. If the technologies incorporated are less mature (as measured by their Technology Readiness Level - TRL), then the LCC not only increases but the degree of increase is difficult to predict. Consequently, new programs avoid incorporating technologies unless they are quite mature, generally TRL greater than or equal to 7 (system prototype demonstrated in a space environment) to allow better predictability of the DDT&E phase costs unless there is no alternative. On the other hand, technology development programs rarely develop technologies beyond TRL 6 (system/subsystem model or prototype demonstrated in a relevant environment). Currently the lack of development funds beyond TRL 6 and the major funding required for full scale development leave little or no funding available to prototype TRL 6 concepts so that hardware would be in the ready mode for safe, reliable and cost effective incorporation. The net effect is that each new program either incorporates little new technology or has longer development schedules and costs, and higher LCC, than planned. This paper presents methods to ensure that advanced technologies are incorporated into future programs while providing a greater accuracy of predicting their LCC. One method is having a dedicated organization to develop X-series vehicles or separate prototypes carried on other vehicles. The question of whether such an organization should be independent of NASA and/or have an independent funding source is discussed. Other methods are also discussed. How to make the choice of which technologies to pursue to the prototype level is also discussed since, to achieve better LCC, first the selection of the appropriate technologies.
Acoustic fatigue life prediction for nonlinear structures with multiple resonant modes
NASA Technical Reports Server (NTRS)
Miles, R. N.
1992-01-01
This report documents an effort to develop practical and accurate methods for estimating the fatigue lives of complex aerospace structures subjected to intense random excitations. The emphasis of the current program is to construct analytical schemes for performing fatigue life estimates for structures that exhibit nonlinear vibration behavior and that have numerous resonant modes contributing to the response.
Clarke, M G; Kennedy, K P; MacDonagh, R P
2009-01-01
To develop a clinical prediction model enabling the calculation of an individual patient's life expectancy (LE) and survival probability based on age, sex, and comorbidity for use in the joint decision-making process regarding medical treatment. A computer software program was developed with a team of 3 clinicians, 2 professional actuaries, and 2 professional computer programmers. This incorporated statistical spreadsheet and database access design methods. Data sources included life insurance industry actuarial rating factor tables (public and private domain), Government Actuary Department UK life tables, professional actuarial sources, and evidence-based medical literature. The main outcome measures were numerical and graphical display of comorbidity-adjusted LE; 5-, 10-, and 15-year survival probability; in addition to generic UK population LE. Nineteen medical conditions, which impacted significantly on LE in actuarial terms and were commonly encountered in clinical practice, were incorporated in the final model. Numerical and graphical representations of statistical predictions of LE and survival probability were successfully generated for patients with either no comorbidity or a combination of the 19 medical conditions included. Validation and testing, including actuarial peer review, confirmed consistency with the data sources utilized. The evidence-based actuarial data utilized in this computer program design represent a valuable resource for use in the clinical decision-making process, where an accurate objective assessment of patient LE can so often make the difference between patients being offered or denied medical and surgical treatment. Ongoing development to incorporate additional comorbidities and enable Web-based access will enhance its use further.
Meeting the Need to Belong: Predicting Effects of a Friendship Enrichment Program for Older Women
ERIC Educational Resources Information Center
Stevens, Nan L.; Martina, Camille M. S.; Westerhof, Gerben J.
2006-01-01
Purpose: This study explores the effects of participation in a program designed to enrich friendship and reduce loneliness among women in later life. Several hypotheses based on the need to belong, socioemotional selectivity theory, and the social compensation model were tested. Design and Methods: Study 1 involved two measurement points, one at…
J.E. Winandy; P.K. Lebow; J.F. Murphy
2002-01-01
Research programs throughout North America are increasingly focusing on understanding and defining the salient issues of wood durability and maintaining and extending the serviceability of existing wood structures. This report presents the findings and implications of a 10-year research program, carried out at the USDA Forest Service, Forest Products Laboratory, to...
NASA Technical Reports Server (NTRS)
Levine, S. R.
1982-01-01
A first-cut integrated environmental attack life prediction methodology for hot section components is addressed. The HOST program is concerned with oxidation and hot corrosion attack of metallic coatings as well as their degradation by interdiffusion with the substrate. The effects of the environment and coatings on creep/fatigue behavior are being addressed through a joint effort with the Fatigue sub-project. An initial effort will attempt to scope the problem of thermal barrier coating life prediction. Verification of models will be carried out through benchmark rig tests including a 4 atm. replaceable blade turbine and a 50 atm. pressurized burner rig.
Musekamp, Gunda; Schuler, Michael; Seekatz, Bettina; Bengel, Jürgen; Faller, Hermann; Meng, Karin
2017-02-15
Heart failure (HF) patient education aims to foster patients' self-management skills. These are assumed to bring about, in turn, improvements in distal outcomes such as quality of life. The purpose of this study was to test the hypothesis that change in self-reported self-management skills observed after participation in self-management education predicts changes in physical and mental quality of life and depressive symptoms up to one year thereafter. The sample comprised 342 patients with chronic heart failure, treated in inpatient rehabilitation clinics, who received a heart failure self-management education program. Latent change modelling was used to analyze relationships between both short-term (during inpatient rehabilitation) and intermediate-term (after six months) changes in self-reported self-management skills and both intermediate-term and long-term (after twelve months) changes in physical and mental quality of life and depressive symptoms. Short-term changes in self-reported self-management skills predicted intermediate-term changes in mental quality of life and long-term changes in physical quality of life. Intermediate-term changes in self-reported self-management skills predicted long-term changes in all outcomes. These findings support the assumption that improvements in self-management skills may foster improvements in distal outcomes.
ERIC Educational Resources Information Center
Kearney, Matthew; Treagust, David F.; Yeo, Shelley; Zadnik, Marjan G.
2001-01-01
Discusses student and teacher perceptions of a new development in the use of the predict-observe-explain (POE) strategy. This development involves the incorporation of POE tasks into a multimedia computer program that uses real-life, digital video clips of difficult, expensive, time consuming, or dangerous scenarios as stimuli for these tasks.…
Effects of surface chemistry on hot corrosion life: Overview
NASA Technical Reports Server (NTRS)
Merutka, J.
1982-01-01
This program concentrates on analyzing a limited number of hot corroded components from the field and the carrying out of a series of controlled laboratory experiments to establish the effects of oxide scale and coating chemistry on hot corrosion life. This is to be determined principally from the length of the incubation period, the investigation of the mechanisms of hot corrosion attack, and the fitting of the data generated from the test exposure experiments to an empirical life prediction model.
The NASA Space Radiation Health Program
NASA Technical Reports Server (NTRS)
Schimmerling, W.; Sulzman, F. M.
1994-01-01
The NASA Space Radiation Health Program is a part of the Life Sciences Division in the Office of Space Science and Applications (OSSA). The goal of the Space Radiation Health Program is development of scientific bases for assuring adequate radiation protection in space. A proposed research program will determine long-term health risks from exposure to cosmic rays and other radiation. Ground-based animal models will be used to predict risk of exposures at varying levels from various sources and the safe levels for manned space flight.
Life prediction and constitutive models for engine hot section anisotropic materials program
NASA Technical Reports Server (NTRS)
Swanson, G. A.; Linask, I.; Nissley, D. M.; Norris, P. P.; Meyer, T. G.; Walker, K. P.
1986-01-01
This report presents the results of the first year of a program designed to develop life prediction and constitutive models for two coated single crystal alloys used in gas turbine airfoils. The two alloys are PWA 1480 and Alloy 185. The two oxidation resistant coatings are PWA 273, an aluminide coating, and PWA 286, an overlay NiCoCrAlY coating. To obtain constitutive and/or fatigue data, tests were conducted on coated and uncoated PWA 1480 specimens tensilely loaded in the 100 , 110 , 111 , and 123 directions. A literature survey of constitutive models was completed for both single crystal alloys and metallic coating materials; candidate models were selected. One constitutive model under consideration for single crystal alloys applies Walker's micromechanical viscoplastic formulation to all slip systems participating in the single crystal deformation. The constitutive models for the overlay coating correlate the viscoplastic data well. For the aluminide coating, a unique test method is under development. LCF and TMF tests are underway. The two coatings caused a significant drop in fatigue life, and each produced a much different failure mechanism.
DOT National Transportation Integrated Search
1971-05-01
This report is the result of a research program in which various types of submerged drainage structures were evaluated in an effort to determine the life expectancy of such a structure. California-s method of predicting the behavior pattern of submer...
NASA Technical Reports Server (NTRS)
Harkness, J. D.
1980-01-01
Evaluation tests of 10 nickel cadmium cells are described. Although pressures were greater than what normally was exhibited by General Electric cells in the past, it is recommended that these cells be placed on life test simulating the predicted Dynamic Explorer flight profiles.
NASA gear research and its probable effect on rotorcraft transmission design
NASA Technical Reports Server (NTRS)
Zaretsky, E. V.; Townsend, D. P.; Coy, J. J.
1979-01-01
The results of the NASA gear research is reviewed as well as those programs which are presently being undertaken. Research programs studying pitting fatigue, gear steels and processing, life prediction methods, gear design and dynamics, elastohydrodynamic lubrication, lubrication methods and gear noise are presented. The impact of advanced gear research technology on rotorcraft transmission design is discussed.
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.
NASA Technical Reports Server (NTRS)
Herman, Daniel A.
2010-01-01
The NASA s Evolutionary Xenon Thruster (NEXT) program is tasked with significantly improving and extending the capabilities of current state-of-the-art NSTAR thruster. The service life capability of the NEXT ion thruster is being assessed by thruster wear test and life-modeling of critical thruster components, such as the ion optics and cathodes. The NEXT Long-Duration Test (LDT) was initiated to validate and qualify the NEXT thruster propellant throughput capability. The NEXT thruster completed the primary goal of the LDT; namely to demonstrate the project qualification throughput of 450 kg by the end of calendar year 2009. The NEXT LDT has demonstrated 30,352 hr of operation and processed 490 kg of xenon throughput--surpassing the NSTAR Extended Life Test hours demonstrated and more than double the throughput demonstrated by the NSTAR flight-spare. Thruster performance changes have been consistent with a priori predictions. Thruster erosion has been minimal and consistent with the thruster service life assessment, which predicts the first failure mode at greater than 750 kg throughput. The life-limiting failure mode for NEXT is predicted to be loss of structural integrity of the accelerator grid due to erosion by charge-exchange ions.
Fatigue life prediction modeling for turbine hot section materials
NASA Technical Reports Server (NTRS)
Halford, G. R.; Meyer, T. G.; Nelson, R. S.; Nissley, D. M.; Swanson, G. A.
1989-01-01
A major objective of the fatigue and fracture efforts under the NASA Hot Section Technology (HOST) program was to significantly improve the analytic life prediction tools used by the aeronautical gas turbine engine industry. This was achieved in the areas of high-temperature thermal and mechanical fatigue of bare and coated high-temperature superalloys. The cyclic crack initiation and propagation resistance of nominally isotropic polycrystalline and highly anisotropic single crystal alloys were addressed. Life prediction modeling efforts were devoted to creep-fatigue interaction, oxidation, coatings interactions, multiaxiality of stress-strain states, mean stress effects, cumulative damage, and thermomechanical fatigue. The fatigue crack initiation life models developed to date include the Cyclic Damage Accumulation (CDA) and the Total Strain Version of Strainrange Partitioning (TS-SRP) for nominally isotropic materials, and the Tensile Hysteretic Energy Model for anisotropic superalloys. A fatigue model is being developed based upon the concepts of Path-Independent Integrals (PII) for describing cyclic crack growth under complex nonlinear response at the crack tip due to thermomechanical loading conditions. A micromechanistic oxidation crack extension model was derived. The models are described and discussed.
Fatigue life prediction modeling for turbine hot section materials
NASA Technical Reports Server (NTRS)
Halford, G. R.; Meyer, T. G.; Nelson, R. S.; Nissley, D. M.; Swanson, G. A.
1988-01-01
A major objective of the fatigue and fracture efforts under the Hot Section Technology (HOST) program was to significantly improve the analytic life prediction tools used by the aeronautical gas turbine engine industry. This was achieved in the areas of high-temperature thermal and mechanical fatigue of bare and coated high-temperature superalloys. The cyclic crack initiation and propagation resistance of nominally isotropic polycrystalline and highly anisotropic single crystal alloys were addressed. Life prediction modeling efforts were devoted to creep-fatigue interaction, oxidation, coatings interactions, multiaxiality of stress-strain states, mean stress effects, cumulative damage, and thermomechanical fatigue. The fatigue crack initiation life models developed to date include the Cyclic Damage Accumulation (CDA) and the Total Strain Version of Strainrange Partitioning (TS-SRP) for nominally isotropic materials, and the Tensile Hysteretic Energy Model for anisotropic superalloys. A fatigue model is being developed based upon the concepts of Path-Independent Integrals (PII) for describing cyclic crack growth under complex nonlinear response at the crack tip due to thermomechanical loading conditions. A micromechanistic oxidation crack extension model was derived. The models are described and discussed.
Stochastic-Strength-Based Damage Simulation of Ceramic Matrix Composite Laminates
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Mital, Subodh K.; Murthy, Pappu L. N.; Bednarcyk, Brett A.; Pineda, Evan J.; Bhatt, Ramakrishna T.; Arnold, Steven M.
2016-01-01
The Finite Element Analysis-Micromechanics Analysis Code/Ceramics Analysis and Reliability Evaluation of Structures (FEAMAC/CARES) program was used to characterize and predict the progressive damage response of silicon-carbide-fiber-reinforced reaction-bonded silicon nitride matrix (SiC/RBSN) composite laminate tensile specimens. Studied were unidirectional laminates [0] (sub 8), [10] (sub 8), [45] (sub 8), and [90] (sub 8); cross-ply laminates [0 (sub 2) divided by 90 (sub 2),]s; angled-ply laminates [plus 45 (sub 2) divided by -45 (sub 2), ]s; doubled-edge-notched [0] (sub 8), laminates; and central-hole laminates. Results correlated well with the experimental data. This work was performed as a validation and benchmarking exercise of the FEAMAC/CARES program. FEAMAC/CARES simulates stochastic-based discrete-event progressive damage of ceramic matrix composite and polymer matrix composite material structures. It couples three software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/Life), and (3) the Abaqus finite element analysis program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating-unit-cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC, and Abaqus is used to model the overall composite structure. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events that incrementally progress until ultimate structural failure.
Development tests for the 2.5 megawatt Mod-2 wind turbine generator
NASA Technical Reports Server (NTRS)
Andrews, J. S.; Baskin, J. M.
1982-01-01
The 2.5 megawatt MOD-2 wind turbine generator test program is discussed. The development of the 2.5 megawatt MOD-2 wind turbine generator included an extensive program of testing which encompassed verification of analytical procedures, component development, and integrated system verification. The test program was to assure achievement of the thirty year design operational life of the wind turbine system as well as to minimize costly design modifications which would otherwise have been required during on site system testing. Computer codes were modified, fatigue life of structure and dynamic components were verified, mechanical and electrical component and subsystems were functionally checked and modified where necessary to meet system specifications, and measured dynamic responses of coupled systems confirmed analytical predictions.
International Space Station Bacteria Filter Element Service Life Evaluation
NASA Technical Reports Server (NTRS)
Perry, J. L.
2005-01-01
The International Space Station (ISS) uses high-efficiency particulate air filters to remove particulate matter from the cabin atmosphere. Known as bacteria filter elements (BFEs), there are 13 elements deployed on board the ISS's U.S. segment in the flight 4R assembly level. The preflight service life prediction of 1 yr for the BFEs is based upon engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS program resources. Testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are provided.
Generation of Finite Life Distributional Goodman Diagrams for Reliability Prediction
NASA Technical Reports Server (NTRS)
Kececioglu, D.; Guerrieri, W. N.
1971-01-01
The methodology of developing finite life distributional Goodman diagrams and surfaces is described for presenting allowable combinations of alternating stress and mean stress to the design engineer. The combined stress condition is that of an alternating bending stress and a constant shear stress. The finite life Goodman diagrams and surfaces are created from strength distributions developed at various ratios of alternating to mean stress at particular cycle life values. The conclusions indicate that the Von Mises-Hencky ellipse, for cycle life values above 1000 cycles, is an adequate model of the finite life Goodman diagram. In addition, suggestions are made which reduce the number of experimental data points required in a fatigue data acquisition program.
Prestraining and Its Influence on Subsequent Fatigue Life
NASA Technical Reports Server (NTRS)
Halford, Gary R.; Mcgaw, Michael A.; Kalluri, Sreeramesh
1995-01-01
An experimental program was conducted to study the damaging effects of tensile and compressive prestrains on the fatigue life of nickel-base, Inconel 718 superalloy at room temperature. To establish baseline fatigue behavior, virgin specimens with a solid uniform gage section were fatigued to failure under fully-reversed strain-control. Additional specimens were prestrained to 2 percent, 5 percent, and 10 percent (engineering strains) in the tensile direction and to 2 percent (engineering strain) in the compressive direction under stroke-control, and were subsequently fatigued to failure under fully-reversed strain-control. Experimental results are compared with estimates of remaining fatigue lives (after prestraining) using three life prediction approaches: (1) the Linear Damage Rule; (2) the Linear Strain and Life Fraction Rule; and (3) the nonlinear Damage Curve Approach. The Smith-Watson-Topper parameter was used to estimate fatigue lives in the presence of mean stresses. Among the cumulative damage rules investigated, best remaining fatigue life predictions were obtained with the nonlinear Damage Curve Approach.
A computer program for cyclic plasticity and structural fatigue analysis
NASA Technical Reports Server (NTRS)
Kalev, I.
1980-01-01
A computerized tool for the analysis of time independent cyclic plasticity structural response, life to crack initiation prediction, and crack growth rate prediction for metallic materials is described. Three analytical items are combined: the finite element method with its associated numerical techniques for idealization of the structural component, cyclic plasticity models for idealization of the material behavior, and damage accumulation criteria for the fatigue failure.
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.
Pick, Susan; Givaudan, Martha; Sirkin, Jenna; Ortega, Isaac
2007-10-01
Literature suggests that communication is a protective factor against high-risk sexual behavior. This study assessed the impact of a fourth-grade communication-centered life skills program on attitudes, norms, self-efficacy, behaviors, and intentions toward communication about difficult subjects. Participants included 1,581 low-income Mexican elementary-school children, divided into experimental and control groups. Teachers were trained to replicate the program as part of the school curriculum over 15 to 20 weeks. Students completed self-report questionnaires before and after the program. Multilevel analyses demonstrated the program's statistically significant positive impact on communication about attitudes, self-efficacy, intentions, and behavior; perception of sociocultural norms regarding communication transformed as a result of the program. Gender significantly predicted differences in communication: with respect to attitudes, self-efficacy, and intentions. The results show that early intervention programs targeting communication about difficult subjects can prevent risky sexual behavior and its consequences (e.g., HIV/AIDS) and influence perception of norms and gender roles.
Improved High-Cycle Fatigue (HCF) Life Prediction
2001-01-01
fatigue in 2024 - T351 aluminum alloy ’, Wear 221, 24-36. Appendix 6C CHARACTERIZATION OF FRETTING FATIGUE INITIATED CRACKS P.J. Golden A.F...0.8. To evaluate the effects of surface residual stresses on notch fatigue life , shot peened specimens were tested at R = -1.0 and 0.1. Data in...Behavior - Response • The undamaged fatigue test program demonstrates the sensitivity of surface effects (for different
Preschool life skills: Recent advancements and future directions.
Fahmie, Tara A; Luczynski, Kevin C
2018-01-01
Over the past decade, researchers have replicated and extended research on the preschool life skills (PLS) program developed by Hanley, Heal, Tiger, and Ingvarsson (2007). This review summarizes recent research with respect to maximizing skill acquisition, improving generality, evaluating feasibility and acceptability, and testing predictions of the initial PLS study. For each area, we suggest directions for future research. © 2018 Society for the Experimental Analysis of Behavior.
Evaluation program for secondary spacecraft cells
NASA Technical Reports Server (NTRS)
Christy, D. E.; Harkness, J. D.
1973-01-01
A life cycle test of secondary electric batteries for spacecraft applications was conducted. A sample number of nickel cadmium batteries were subjected to general performance tests to determine the limit of their actual capabilities. Weaknesses discovered in cell design are reported and aid in research and development efforts toward improving the reliability of spacecraft batteries. A statistical analysis of the life cycle prediction and cause of failure versus test conditions is provided.
A Roadmap for Aircraft Engine Life Extending Control
NASA Technical Reports Server (NTRS)
Guo, Ten-Huei
2001-01-01
The concept of Aircraft Engine Life Extending Control is introduced. A brief description of the tradeoffs between performance and engine life are first explained. The overall goal of the life extending controller is to reduce the engine operating cost by extending the on-wing engine life while improving operational safety. The research results for NASA's Rocket Engine life extending control program are also briefly described. Major building blocks of the Engine Life Extending Control architecture are examined. These blocks include: life prediction models, engine operation models, stress and thermal analysis tools, control schemes, and intelligent control systems. The technology areas that would likely impact the successful implementation of an aircraft engine life extending control are also briefly described. Near, intermediate, and long term goals of NASA's activities are also presented.
Willie, Tiara C; Powell, Adeya; Kershaw, Trace
2016-02-01
Adolescent and young mothers transitioning from pregnancy to postpartum need to maintain an optimal quality of life. Stress and exposure to violence (e.g., intimate partner violence (IPV), nonpartner violence) are predictors of poor quality of life for adult women; however, these associations remain understudied among adolescent and young mothers in urban areas. Guided by the social ecological model, the current study created a latent variable, urban social stress, to examine the impact of the urban social environment (i.e., stressful life events, discrimination, family stress, and neighborhood problems) on the quality of life of adolescent and young mothers during both pregnancy and postpartum. The current study is a secondary data analysis of a prospective cohort study of 296 expectant young mothers recruited at obstetrics and gynecology clinics. Results from structural equation and multigroup models found that higher urban social stress predicted lower mental and physical quality of life during pregnancy, but these associations were significantly stronger for IPV-exposed and nonpartner violence-exposed mothers. In the postpartum period, higher urban social stress predicted lower mental and physical quality of life, but these associations were significantly stronger for IPV-unexposed and nonpartner violence-exposed mothers. Stress reduction programs need to help adolescent and young mothers in urban areas develop stress management skills specific to urban social stress. Pregnancy and parenting programs need to be tailored to the specific needs of young mothers in urban areas by becoming sensitive to the role of IPV and nonpartner violence in these young women's lives.
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.
Comparative analysis of economic models in selected solar energy computer programs
NASA Astrophysics Data System (ADS)
Powell, J. W.; Barnes, K. A.
1982-01-01
The economic evaluation models in five computer programs widely used for analyzing solar energy systems (F-CHART 3.0, F-CHART 4.0, SOLCOST, BLAST, and DOE-2) are compared. Differences in analysis techniques and assumptions among the programs are assessed from the point of view of consistency with the Federal requirements for life cycle costing (10 CFR Part 436), effect on predicted economic performance, and optimal system size, case of use, and general applicability to diverse systems types and building types. The FEDSOL program developed by the National Bureau of Standards specifically to meet the Federal life cycle cost requirements serves as a basis for the comparison. Results of the study are illustrated in test cases of two different types of Federally owned buildings: a single family residence and a low rise office building.
Zimmer, Cédric; Larriva, Maria; Boogert, Neeltje J.; Spencer, Karen A.
2017-01-01
An interesting aspect of developmental programming is the existence of transgenerational effects that influence offspring characteristics and performance later in life. These transgenerational effects have been hypothesized to allow individuals to cope better with predictable environmental fluctuations and thus facilitate adaptation to changing environments. Here, we test for the first time how early-life stress drives developmental programming and transgenerational effects of maternal exposure to early-life stress on several phenotypic traits in their offspring in a functionally relevant context using a fully factorial design. We manipulated pre- and/or post-natal stress in both Japanese quail mothers and offspring and examined the consequences for several stress-related traits in the offspring generation. We show that pre-natal stress experienced by the mother did not simply affect offspring phenotype but resulted in the inheritance of the same stress-coping traits in the offspring across all phenotypic levels that we investigated, shaping neuroendocrine, physiological and behavioural traits. This may serve mothers to better prepare their offspring to cope with later environments where the same stressors are experienced. PMID:28387355
NASA gear research and its probable effect on rotorcraft transmission design
NASA Technical Reports Server (NTRS)
Zaretsky, E. V.; Townsend, D. P.; Coy, J. J.
1979-01-01
The NASA Lewis Research Center devised a comprehensive gear technology research program beginning in 1969, the results of which are being integrated into the NASA civilian Helicopter Transmission System Technology Program. Attention is given to the results of this gear research and those programs which are presently being undertaken. In addition, research programs studying pitting fatigue, gear steels and processing, life prediction methods, gear design and dynamics, elastohydrodynamic lubrication, lubrication methods and gear noise are presented. Finally, the impact of advanced gear research technology on rotorcraft transmission design is discussed.
Thermal barrier coating life prediction model development
NASA Technical Reports Server (NTRS)
Strangman, T. E.; Neumann, J. F.; Tasooji, A.
1985-01-01
This program focuses on predicting the lives of two types of strain-tolerant and oxidation-resistant thermal barrier coating (TBC) systems that are produced by commercial coating suppliers to the gas turbine industry. The plasma-sprayed TBC system is composed of a low pressure, plasma sprayed applied, oxidation resistant NiCrAlY bond coating. The other system is an air plasma sprayed yttria (8 percent) partially stabilized zirconia insulative layer.
Transpiration cooled throat for hydrocarbon rocket engines
NASA Technical Reports Server (NTRS)
May, Lee R.; Burkhardt, Wendel M.
1991-01-01
The objective for the Transpiration Cooled Throat for Hydrocarbon Rocket Engines Program was to characterize the use of hydrocarbon fuels as transpiration coolants for rocket nozzle throats. The hydrocarbon fuels investigated in this program were RP-1 and methane. To adequately characterize the above transpiration coolants, a program was planned which would (1) predict engine system performance and life enhancements due to transpiration cooling of the throat region using analytical models, anchored with available data; (2) a versatile transpiration cooled subscale rocket thrust chamber was designed and fabricated; (3) the subscale thrust chamber was tested over a limited range of conditions, e.g., coolant type, chamber pressure, transpiration cooled length, and coolant flow rate; and (4) detailed data analyses were conducted to determine the relationship between the key performance and life enhancement variables.
Thermal barrier coating life-prediction model development
NASA Technical Reports Server (NTRS)
Strangman, T. E.; Neumann, J.
1985-01-01
Life predictions are made for two types of strain-tolerant and oxidation-resistant Thermal Barrier Coating (TBC) systems produced by commercial coating suppliers to the gas turbine industry. The plasma-sprayed TBC system, composed of a low-pressure plasma spray (LPPS) applied oxidation-resistant NiCrAlY bond coating and an air-plasma-sprayed yttria (8 percent) partially stabilized zirconia insulative layer, is applied by both Chromalloy and Klock. The second type of TBC is applied by the electron-beam/physical vapor deposition process by Temescal. Thermomechanical and thermochemical testing of the program TBCs is in progress. A number of the former tests has been completed. Fracture mechanics data for the Chromalloy plasma-sprayed TBC system indicate that the cohesive toughness of the zirconia layer is increased by thermal cycling and reduced by high temperature exposure at 1150 C. Eddy current technology feasibility has been established with respect to nondestructively measuring zirconia layer thickness of a TBC system. High pressure turbine blades have been coated with program TBC systems for a piggyback test in a TFE731-5 turbofan factory engine test. Data from this test will be used to validate the TBC life models.
Kindt, Karlijn C M; Kleinjan, Marloes; Janssens, Jan M A M; Scholte, Ron H J
2015-11-01
Previous research has established that cognitive theory-based depression prevention programs aiming change in negative cognitive style in early adolescents do not have strong effects in universal settings. Although theories suggest that a negative cognitive style precedes depressive symptoms, empirical findings are mixed. We hypothesized that negative cognitive style may not predict depressive symptoms in adolescents with normative depressive symptoms. Depressive symptoms, negative cognitive style and dependent negative life events were assessed in young adolescents (N = 1343; mean age = 13.4 years, SD = 0.77; 52.3 % girls) at four time points over an 18-month period. Using a cross-lagged panel design, results revealed that depressive symptoms predicted a negative cognitive style but not vice versa. However, when including dependent negative life events as a variable, depressive symptoms did not prospect a negative cognitive style consistently. When dependent negative life events were used as a time-varying covariate, depressive symptoms and a negative cognitive style were not related. We concluded that negative cognitive style is not predictive of depressive symptoms in a community sample of young adolescents. Moreover, the findings suggest that longitudinal relationships between depressive symptoms and a negative cognitive style are not meaningful when dependent negative life events are not considered.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Puskar, Joseph David; Quintana, Michael A.; Sorensen, Neil Robert
A program is underway at Sandia National Laboratories to predict long-term reliability of photovoltaic (PV) systems. The vehicle for the reliability predictions is a Reliability Block Diagram (RBD), which models system behavior. Because this model is based mainly on field failure and repair times, it can be used to predict current reliability, but it cannot currently be used to accurately predict lifetime. In order to be truly predictive, physics-informed degradation processes and failure mechanisms need to be included in the model. This paper describes accelerated life testing of metal foil tapes used in thin-film PV modules, and how tape jointmore » degradation, a possible failure mode, can be incorporated into the model.« less
NASA Technical Reports Server (NTRS)
Hirschberg, M. H.
1978-01-01
Twenty laboratories in six countries participated in testing their own materials of interest under their own laboratory conditions. In this way the results obtained provided validation of the Strainrange Partitioning (SRP) method for a wide range of materials and insured maximum usefulness to each of the participating laboratories. The various investigators shared their findings, thus providing the basis for an in-depth evaluation of the SRP method. While the results were variable from laboratory to laboratory, most investigators agreed that the SRP method was a significant step toward life prediction in the presence of high temperature and cyclic stresses.
Modeling of rolling element bearing mechanics
NASA Technical Reports Server (NTRS)
Greenhill, L. M.
1991-01-01
Roller element bearings provide the primary mechanical interface between rotating and nonrotating components in the high performance turbomachinery of the Space Shuttle Main Engine (SSME). Knowledge of bearing behavior under various loading and environmental conditions is essential to predicting and understanding the overall behavior of turbopumps, including rotordynamic stability, critical speeds and bearing life. The objective is to develop mathematical models and computer programs to describe the mechanical behavior of ball and cylinder roller bearings under the loading and environmental conditions encountered in the SSME and future high performance rocket engines. This includes characteristics such as nonlinear load/motion relationships, stiffness and damping, rolling element loads for life prediction, and roller and cage stability.
NASA Technical Reports Server (NTRS)
Litt, Jonathan S.; Soditus, Sherry; Hendricks, Robert C.; Zaretsky, Erwin V.
2002-01-01
Over the past two decades there has been considerable effort by NASA Glenn and others to develop probabilistic codes to predict with reasonable engineering certainty the life and reliability of critical components in rotating machinery and, more specifically, in the rotating sections of airbreathing and rocket engines. These codes have, to a very limited extent, been verified with relatively small bench rig type specimens under uniaxial loading. Because of the small and very narrow database the acceptance of these codes within the aerospace community has been limited. An alternate approach to generating statistically significant data under complex loading and environments simulating aircraft and rocket engine conditions is to obtain, catalog and statistically analyze actual field data. End users of the engines, such as commercial airlines and the military, record and store operational and maintenance information. This presentation describes a cooperative program between the NASA GRC, United Airlines, USAF Wright Laboratory, U.S. Army Research Laboratory and Australian Aeronautical & Maritime Research Laboratory to obtain and analyze these airline data for selected components such as blades, disks and combustors. These airline data will be used to benchmark and compare existing life prediction codes.
Gear crack propagation investigations
NASA Technical Reports Server (NTRS)
Lewicki, David G.; Ballarini, Roberto
1996-01-01
Analytical and experimental studies were performed to investigate the effect of gear rim thickness on crack propagation life. The FRANC (FRacture ANalysis Code) computer program was used to simulate crack propagation. The FRANC program used principles of linear elastic fracture mechanics, finite element modeling, and a unique re-meshing scheme to determine crack tip stress distributions, estimate stress intensity factors, and model crack propagation. Various fatigue crack growth models were used to estimate crack propagation life based on the calculated stress intensity factors. Experimental tests were performed in a gear fatigue rig to validate predicted crack propagation results. Test gears were installed with special crack propagation gages in the tooth fillet region to measure bending fatigue crack growth. Good correlation between predicted and measured crack growth was achieved when the fatigue crack closure concept was introduced into the analysis. As the gear rim thickness decreased, the compressive cyclic stress in the gear tooth fillet region increased. This retarded crack growth and increased the number of crack propagation cycles to failure.
ISO Key Project: Exploring the Full Range of Quasar/AGN Properties
NASA Technical Reports Server (NTRS)
Wilkes, Belinda J.
1997-01-01
The ISOPHOT team have developed new recommendations for observing faint sources with ISHPOHT which involve small rasters rather than chopping. This was finalized around Feb 1997 and following this we re-designed the observations for the remainder of our observing time. We had put our program on hold in September when it became clear that chopped observations had major problems. The revised program, which included re-observation at long wavelengths using rasters for a number of high-priority targets and re-specification of new observations of others, was released in April 1997. The latest prediction for the satellite lifetime has extended its life until April 1998. Our project has been allocated a 15% increase in our observing time as a result of this life extension. We are currently working on setting priorities in order to determine which targets to include in this additional time. This will help to offset some of the targets lost due to the significant decrease in detector sensitivity over pre-flight predictions.
Reyes, J F; Wood, J G; Beutels, P; Macartney, K; McIntyre, P; Menzies, R; Mealing, N; Newall, A T
2017-01-05
Universal vaccination against rotavirus was included in the funded Australian National Immunisation Program in July 2007. Predictive cost-effectiveness models assessed the program before introduction. We conducted a retrospective economic evaluation of the Australian rotavirus program using national level post-implementation data on vaccine uptake, before-after measures of program impact and published estimates of excess intussusception cases. These data were used as inputs into a multi-cohort compartmental model which assigned cost and quality of life estimates to relevant health states, adopting a healthcare payer perspective. The primary outcome was discounted cost per quality adjusted life year gained, including or excluding unspecified acute gastroenteritis (AGE) hospitalisations. Relative to the baseline period (1997-2006), over the 6years (2007-2012) after implementation of the rotavirus program, we estimated that ∼77,000 hospitalisations (17,000 coded rotavirus and 60,000 unspecified AGE) and ∼3 deaths were prevented, compared with an estimated excess of 78 cases of intussusception. Approximately 90% of hospitalisations prevented were in children <5years, with evidence of herd protection in older age groups. The program was cost-saving when observed changes (declines) in both hospitalisations coded as rotavirus and as unspecified AGE were attributed to the rotavirus vaccine program. The adverse impact of estimated excess cases of intussusception was far outweighed by the benefits of the program. The inclusion of herd impact and declines in unspecified AGE hospitalisations resulted in the value for money achieved by the Australian rotavirus immunisation program being substantially greater than predicted bypre-implementation models, despite the potential increased cases of intussusception. This Australian experience is likely to be relevant to high-income countries yet to implement rotavirus vaccination programs. Copyright © 2016. Published by Elsevier Ltd.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Price, Jeffrey
Solar Turbines Incorporated (Solar), under cooperative agreement number DE-FC26-0CH11049, has conducted development activities to improve the durability of the Mercury 50 combustion system to 30,000 hours life and reduced life cycle costs. This project is part of Advanced Materials in the Advanced Industrial Gas Turbines program in DOE's Office of Distributed Energy. The targeted development engine was the Mercury{trademark} 50 gas turbine, which was developed by Solar under the DOE Advanced Turbine Systems program (DOE contract number DE-FC21-95MC31173). As a generator set, the Mercury 50 is used for distributed power and combined heat and power generation and is designed tomore » achieve 38.5% electrical efficiency, reduced cost of electricity, and single digit emissions. The original program goal was 20,000 hours life, however, this goal was increased to be consistent with Solar's standard 30,000 hour time before overhaul for production engines. Through changes to the combustor design to incorporate effusion cooling in the Generation 3 Mercury 50 engine, which resulted in a drop in the combustor wall temperature, the current standard thermal barrier coated liner was predicted to have 18,000 hours life. With the addition of the advanced materials technology being evaluated under this program, the combustor life is predicted to be over 30,000 hours. The ultimate goal of the program was to demonstrate a fully integrated Mercury 50 combustion system, modified with advanced materials technologies, at a host site for a minimum of 4,000 hours. Solar was the Prime Contractor on the program team, which includes participation of other gas turbine manufacturers, various advanced material and coating suppliers, nationally recognized test laboratories, and multiple industrial end-user field demonstration sites. The program focused on a dual path development route to define an optimum mix of technologies for the Mercury 50 and future gas turbine products. For liner and injector development, multiple concepts including high thermal resistance thermal barrier coatings (TBC), oxide dispersion strengthened (ODS) alloys, continuous fiber ceramic composites (CFCC), and monolithic ceramics were evaluated before down-selection to the most promising candidate materials for field evaluation. Preliminary, component and sub-scale testing was conducted to determine material properties and demonstrate proof-of-concept. Full-scale rig and engine testing was used to validated engine performance prior to field evaluation at a Qualcomm Inc. cogeneration site located in San Diego, California. To ensure that the CFCC liners with the EBC proposed under this program would meet the target life, field evaluations of ceramic matrix composite liners in Centaur{reg_sign} 50 gas turbine engines, which had previously been conducted under the DOE sponsored Ceramic Stationary Gas Turbine program (DE-AC02-92CE40960), was continued under this program at commercial end-user sites under Program Subtask 1A - Extended CFCC Materials Durability Testing. The goal of these field demonstrations was to demonstrate significant component life, with milestones of 20,000 and 30,000 hours. Solar personnel monitor the condition of the liners at the field demonstration sites through periodic borescope inspections and emissions measurements. This program was highly successful at evaluating advanced materials and down-selecting promising solutions for use in gas turbine combustions systems. The addition of the advanced materials technology has enabled the predicted life of the Mercury 50 combustion system to reach 30,000 hours, which is Solar's typical time before overhaul for production engines. In particular, a 40 mil thick advanced Thermal Barrier Coating (TBC) system was selected over various other TBC systems, ODS liners and CFCC liners for the 4,000-hour field evaluation under the program. This advanced TBC is now production bill-of-material at various thicknesses up to 40 mils for all of Solar's advanced backside-cooled combustor liners (Centaur 50, Taurus 60, Mars 100, Taurus 70, Taurus 65, Titan 130, Titan 250 and Mercury 50). This TBC coating system significantly outperformed all other TBC systems evaluated under the program. The initial field unit, with the 40 mil advanced TBC developed under this program, has far exceeded the 4,000-hour requirement of the program, accumulating over 20,000 hours of commercial operation at Qualcomm Inc. in San Diego, CA. The 40 mil advanced TBC remains in excellent condition, with no evidence of chipping or spalling. The engine will continue operation until the unit is due for overhaul at approximately 30,000 hours. The Oxide Dispersion Strengthened (ODS) alloy injector tip testing and evaluation was also successful, however, the ODS injector tip development on this program was terminated, primarily due to the fact that the Mercury 50 injector tip was redesigned (Generation 3) by Combustion Engineering.« less
Amdurer, Emily; Boyatzis, Richard E.; Saatcioglu, Argun; Smith, Melvin L.; Taylor, Scott N.
2014-01-01
Career scholars have called for a broader definition of career success by inviting greater exploration of its antecedents. While success in various jobs has been predicted by intelligence and in other studies by competencies, especially in management, long term impact of having intelligence and using competencies has not been examined. Even in collegiate outcome studies, few have examined the longer term impact on graduates' careers or lives. This study assesses the impact of demonstrated emotional, social, and cognitive intelligence competencies assessed at graduation and g measured through GMAT at entry from an MBA program on career and life satisfaction, and career success assessed 5 to 19 years after graduation. Using behavioral measures of competencies (i.e., as assessed by others), we found that emotional intelligence competencies predict career satisfaction and success. Adaptability had a positive impact, but influence had the opposite effect on these career measures and life satisfaction. Life satisfaction was negatively affected by achievement orientation and positively affected by teamwork. Current salary, length of marriage, and being younger at time of graduation positively affect all three measures of life and career satisfaction and career success. GMAT (as a measure of g) predicted life satisfaction and career success to a slight but significant degree in the final model analyzed. Meanwhile, being female and number of children positively affected life satisfaction but cognitive intelligence competencies negatively affected it, and in particular demonstrated systems thinking was negative. PMID:25566128
Amdurer, Emily; Boyatzis, Richard E; Saatcioglu, Argun; Smith, Melvin L; Taylor, Scott N
2014-01-01
Career scholars have called for a broader definition of career success by inviting greater exploration of its antecedents. While success in various jobs has been predicted by intelligence and in other studies by competencies, especially in management, long term impact of having intelligence and using competencies has not been examined. Even in collegiate outcome studies, few have examined the longer term impact on graduates' careers or lives. This study assesses the impact of demonstrated emotional, social, and cognitive intelligence competencies assessed at graduation and g measured through GMAT at entry from an MBA program on career and life satisfaction, and career success assessed 5 to 19 years after graduation. Using behavioral measures of competencies (i.e., as assessed by others), we found that emotional intelligence competencies predict career satisfaction and success. Adaptability had a positive impact, but influence had the opposite effect on these career measures and life satisfaction. Life satisfaction was negatively affected by achievement orientation and positively affected by teamwork. Current salary, length of marriage, and being younger at time of graduation positively affect all three measures of life and career satisfaction and career success. GMAT (as a measure of g) predicted life satisfaction and career success to a slight but significant degree in the final model analyzed. Meanwhile, being female and number of children positively affected life satisfaction but cognitive intelligence competencies negatively affected it, and in particular demonstrated systems thinking was negative.
Environment assisted degradation mechanisms in advanced light metals
NASA Technical Reports Server (NTRS)
Gangloff, R. P.; Stoner, G. E.; Swanson, R. E.
1989-01-01
A multifaceted research program on the performance of advanced light metallic alloys in aggressive aerospace environments, and associated environmental failure mechanisms was initiated. The general goal is to characterize alloy behavior quantitatively and to develop predictive mechanisms for environmental failure modes. Successes in this regard will provide the basis for metallurgical optimization of alloy performance, for chemical control of aggressive environments, and for engineering life prediction with damage tolerance and long term reliability.
Development of an improved method of consolidating fatigue life data
NASA Technical Reports Server (NTRS)
Leis, B. N.; Sampath, S. G.
1978-01-01
A fatigue data consolidation model that incorporates recent advances in life prediction methodology was developed. A combined analytic and experimental study of fatigue of notched 2024-T3 aluminum alloy under constant amplitude loading was carried out. Because few systematic and complete data sets for 2024-T3 were available in the program generated data for fatigue crack initiation and separation failure for both zero and nonzero mean stresses. Consolidations of these data are presented.
Incorporation of Half-Cycle Theory Into Ko Aging Theory for Aerostructural Flight-Life Predictions
NASA Technical Reports Server (NTRS)
Ko, William L.; Tran, Van T.; Chen, Tony
2007-01-01
The half-cycle crack growth theory was incorporated into the Ko closed-form aging theory to improve accuracy in the predictions of operational flight life of failure-critical aerostructural components. A new crack growth computer program was written for reading the maximum and minimum loads of each half-cycle from the random loading spectra for crack growth calculations and generation of in-flight crack growth curves. The unified theories were then applied to calculate the number of flights (operational life) permitted for B-52B pylon hooks and Pegasus adapter pylon hooks to carry the Hyper-X launching vehicle that air launches the X-43 Hyper-X research vehicle. A crack growth curve for each hook was generated for visual observation of the crack growth behavior during the entire air-launching or captive flight. It was found that taxiing and the takeoff run induced a major portion of the total crack growth per flight. The operational life theory presented can be applied to estimate the service life of any failure-critical structural components.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sowell, E.
1979-06-01
The Building Loads Analysis and System Thermodynamics (BLAST) program is a comprehensive set of subprograms for predicting energy consumption in buildings. There are three major subprograms: (1) the space load predicting subprogram, which computes hourly space loads in a building or zone based on user input and hourly weather data; (2) the air distribution system simulation subprogram, which uses the computed space load and user inputs describing the building air-handling system to calculate hot water or steam, chilled water, and electric energy demands; and (3) the central plant simulation program, which simulates boilers, chillers, onsite power generating equipment and solarmore » energy systems and computes monthly and annual fuel and electrical power consumption and plant life cycle cost.« less
Cappe, Emilie; Bolduc, Mélanie; Rougé, Marie-Caroline; Saiag, Marie-Claude; Delorme, Richard
2017-05-01
This study investigated quality of life and adjustment mechanisms in parents of children with Attention-Deficit/Hyperactivity Disorder (ADHD). Ninety parents of children with ADHD completed a sociodemographic questionnaire and self-assessment scales to measure their perceived stress, social support, sense of control, coping strategies and quality of life. ADHD in children negatively affected parents' quality of life, especially their psychological well-being and personal fulfillment. Family and couple relationships, as well as daily life activities, were also affected. The severity of the disorder, perceiving the situation as a threat or a loss, feeling guilty and holding on to irrational beliefs were related to emotion-focused coping strategies and to a poorer quality of life. Furthermore, hyperactivity index and stress ratings relative to perceiving the situation as a threat or a loss, and adopting emotion-focused coping strategies, predicted poorer quality of life. In contrast, perceiving the situation as challenging was related to a greater sense of control and personal fulfillment. Moreover, perceiving the situation as challenging and adopting problem-focused coping strategies predicted better quality of life. The findings highlight the negative effects of ADHD on parent psychological adjustment and underline the need to recommend training programs that improve parenting skills, parents' perceptions concerning their child's behavior disorder and parental functioning.
2011-06-01
provide coverage for servicemembers. Even though insurance actuaries are fairly reliable in predicting deaths in the armed services during peacetime... disability . Mr. Wurtz continues: The SGLI program has insurance companies that have agreed to be "converters.” When an insured wants to convert...Philadelphia, PA; and Chief, Actuarial Staff, VA Regional Office and Insurance Center, Philadelphia, PA. A copy of the 1998 (Thursday, December 17
Forster, Andrea G; Bol, Thijs
2018-02-01
Vocational education is seen as beneficial for the labor market allocation of young people. However, recent studies point to disadvantages later in the life course, where the specific skills that are obtained from vocational education decrease employability. This paper re-evaluates this hypothesis for the Netherlands with an improved measure for the vocational specificity of educational programs, utilizing both vertical (level) and horizontal (field) information on education. More specifically, we use a gradual measure for the linkage strength between education and occupation to predict employment over the life course. Using data from the national Dutch labor force surveys, we show that there is considerable heterogeneity in occupational specificity within the categories of vocational and general educational programs that is masked when using a dichotomous classification of general versus vocational education. In the life course analyses we find that the large early benefits of having vocational education disappear later in the career and turn into a small disadvantage before retirement. Copyright © 2017. Published by Elsevier Inc.
Proven, long-life hydrogen/oxygen thrust chambers for space station propulsion
NASA Technical Reports Server (NTRS)
Richter, G. P.; Price, H. G.
1986-01-01
The development of the manned space station has necessitated the development of technology related to an onboard auxiliary propulsion system (APS) required to provide for various space station attitude control, orbit positioning, and docking maneuvers. A key component of this onboard APS is the thrust chamber design. To develop the required thrust chamber technology to support the Space Station Program, the NASA Lewis Research Center has sponsored development programs under contracts with Aerojet TechSystems Company and with Bell Aerospace Textron Division of Textron, Inc. During the NASA Lewis sponsored program with Aerojet TechSystems, a 25 lb sub f hydrogen/oxygen thruster has been developed and proven as a viable candidate to meet the needs of the Space Station Program. Likewise, during the development program with Bell Aerospace, a 50 lb sub f hydrogen/oxygen Thrust Chamber has been developed and has demonstrated reliable, long-life expectancy at anticipated space station operating conditions. Both these thrust chambers were based on design criteria developed in previous thruster programs and successfully verified in experimental test programs. Extensive thermal analyses and models were used to design the thrusters to achieve total impulse goals of 2 x 10 to the 6th power lb sub f-sec. Test data for each thruster will be compared to the analytical predictions for the performance and heat transfer characteristics. Also, the results of thrust chamber life verification tests will be presented.
Life extension of Structural Repairs – A statistical approach towards efficiency improvement
NASA Astrophysics Data System (ADS)
Deepashri, N. V.; Kalaiyappan, Mohan
2018-05-01
The life extension program of aircraft is taken up whenever aircraft’s intended life reaches close to its DSG (Design Service Goal). The Extended Service Goal (ESG) of an aircraft, in general, and structural repairs, in particular, is arrived at on the basis of F&DT (Fatigue & Damage Tolerance) analysis. Life extension program of aircraft consists of assessment of remaining life of all parts of the aircrafts including structural, mechanical, and electrical and avionics equipment and structural repairs. For life extension of stringer repair, as an example, it is required to re-assess the fatigue life of stringer in the presence of coupling under modified load spectrum. This is achieved by assessing the fatigue life of Web and Outer Flange (OF) part of stringers separately as per F&DT justification philosophy. Assessment of the fatigue life requires determination of stress concentration factor (Kt) for different combination of width, pitch, stringer thickness, coupling thickness and pad-up thickness of all stringer profiles available in different sections of fuselage. Determination of stress concentration factor for Web and Outer Flange of stringer profile covering entire ranges involves substantial number of Finite Element (FE) analysis. In order to optimise the number of FE runs, stress concentration factor is determined under worst repair factors combination (max. plate width; max. thickness; max. pitch; min. rivet dia.; and min. No. of rivets) resulting in conservative value. A parametric study of Web and Outer Flange data across stringer profiles were carried out and proven statistical techniques were used to find the optimal equation to predict stress concentration factor. This in turn reduced number of FE runs substantially for a given range of width, pitch, stringer thickness and so on. The use of optimal equation obtained through regression analysis is able to predict Kt within reasonable accuracy for a given range of inputs.
Šabanagić-Hajrić, Selma; Alajbegović, Azra
2015-02-01
To evaluate the impacts of education level and employment status on health-related quality of life (HRQoL) in multiple sclerosis patients. This study included 100 multiple sclerosis patients treated at the Department of Neurology, Clinical Center of the University of Sarajevo. Inclusion criteria were the Expanded Disability Status Scale (EDSS) score between 1.0 and 6.5, age between 18 and 65 years, stable disease on enrollment. Quality of life (QoL) was evaluated by the Multiple Sclerosis Quality of Life-54 questionnaire (MSQoL-54). Mann-Whitney and Kruskal-Wallis test were used for comparisons. Linear regression analyses were performed to evaluate prediction value of educational level and employment status in predicting MSQOL-54 physical and mental composite scores. Full employment status had positive impact on physical health (54.85 vs. 37.90; p les than 0.001) and mental health (59.55 vs. 45.90; p les than 0.001) composite scores. Employment status retained its independent predictability for both physical (r(2)=0.105) and mental (r(2)=0.076) composite scores in linear regression analysis. Patients with college degree had slightly higher median value of physical (49.36 vs. 45.30) and mental health composite score (66.74 vs. 55.62) comparing to others, without statistically significant difference. Employment proved to be an important factor in predicting quality of life in multiple sclerosis patients. Higher education level may determine better QOL but without significant predictive value. Sustained employment and development of vocational rehabilitation programs for MS patients living in the country with high unemployment level is an important factor in improving both physical and mental health outcomes in MS patients.
Cyclic stress analysis of an air-cooled turbine vane
NASA Technical Reports Server (NTRS)
Kaufman, A.; Gauntner, D. J.; Gauntner, J. W.
1975-01-01
The effects of gas pressure level, coolant temperature, and coolant flow rate on the stress-strain history and life of an air-cooled vane were analyzed using measured and calculated transient metal temperatures and a turbine blade stress analysis program. Predicted failure locations were compared to results from cyclic tests in a static cascade and engine. The results indicate that a high gas pressure was detrimental, a high coolant flow rate somewhat beneficial, and a low coolant temperature the most beneficial to vane life.
A method for predicting service life of zinc rich primers on carbon steel
NASA Technical Reports Server (NTRS)
Hoppesch, C. W.
1986-01-01
The service life of zinc rich primers on carbon steel can be estimated by immersing a primer coated glass slide into an aqueous copper sulfate solution and measuring the amount of zinc that reacts with the copper in 15 minutes. This zinc availability test was used to evaluate eleven primers currently available for which marine beach exposure data was available from previous programs. Results were evaluated and a correlation between zinc availability and ASTM rust grade was shown.
Military engine computational structures technology
NASA Technical Reports Server (NTRS)
Thomson, Daniel E.
1992-01-01
Integrated High Performance Turbine Engine Technology Initiative (IHPTET) goals require a strong analytical base. Effective analysis of composite materials is critical to life analysis and structural optimization. Accurate life prediction for all material systems is critical. User friendly systems are also desirable. Post processing of results is very important. The IHPTET goal is to double turbine engine propulsion capability by the year 2003. Fifty percent of the goal will come from advanced materials and structures, the other 50 percent will come from increasing performance. Computer programs are listed.
NASA Technical Reports Server (NTRS)
Hansen, Patricia A.
2003-01-01
The Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) was deployed on-orbit in February 1997. The contamination program for STIS was stringently controlled as the five-year end-of-life deposition was set at 158, per optical element. Contamination was controlled through materials selection, extensive vacuum outgassing certifications, cleaning techniques, and environmental controls. In addition to ground contamination controls, on-orbit contamination controls were implemented for both the HST servicing mission activities and early post-servicing mission checkout. The extensive contamination control program will be discussed and the STIS on-orbit data will be correlated with the prelaunch analytical predictions.
Intrasystem Analysis Program (IAP) code summaries
NASA Astrophysics Data System (ADS)
Dobmeier, J. J.; Drozd, A. L. S.; Surace, J. A.
1983-05-01
This report contains detailed descriptions and capabilities of the codes that comprise the Intrasystem Analysis Program. The four codes are: Intrasystem Electromagnetic Compatibility Analysis Program (IEMCAP), General Electromagnetic Model for the Analysis of Complex Systems (GEMACS), Nonlinear Circuit Analysis Program (NCAP), and Wire Coupling Prediction Models (WIRE). IEMCAP is used for computer-aided evaluation of electromagnetic compatibility (ECM) at all stages of an Air Force system's life cycle, applicable to aircraft, space/missile, and ground-based systems. GEMACS utilizes a Method of Moments (MOM) formalism with the Electric Field Integral Equation (EFIE) for the solution of electromagnetic radiation and scattering problems. The code employs both full matrix decomposition and Banded Matrix Iteration solution techniques and is expressly designed for large problems. NCAP is a circuit analysis code which uses the Volterra approach to solve for the transfer functions and node voltage of weakly nonlinear circuits. The Wire Programs deal with the Application of Multiconductor Transmission Line Theory to the Prediction of Cable Coupling for specific classes of problems.
Braz Júnior, Donato S; Dornelas de Andrade, Arméle; Teixeira, Andrei S; Cavalcanti, Cléssyo A; Morais, André B; Marinho, Patrícia EM
2015-01-01
Background Exercise intolerance is a common development in patients with chronic obstructive pulmonary disease (COPD). There is little data on the use of an isolated program using vibration platform training on functional capacity in these patients, which is an area that deserves investigation. Aim To investigate the effect of training on a vibrating platform (whole-body vibration [WBV]) on functional performance and quality of life of subjects with COPD. Methods A randomized controlled crossover pilot study with eleven subjects with COPD (forced expiratory volume in 1 second [FEV1]% predicted =14.63±11.14; forced vital capacity [FVC]% predicted =48.84±15.21; FEV1/FVC =47.39±11.63) underwent a 12-week WBV training program. Participants were randomized into the intervention group (IG) undergoing three sessions per week for a total of 12 weeks and control group (CG) without intervention. We evaluated the 6-minute walk test (6MWT), distance walked (DW), duration of the walk (TW), and index of perceived exertion (IPE), quality of life using St George’s Respiratory Questionnaire (SGRQ) and developed a 12-week program of training on a vibrating platform. Results The mean age was 62.91±8.82 years old (72.7% male). The DW increased at the end of training with a difference between groups of 75 m; all domains of the SGRQ improved at the end of training. The effect size Cohen’s d ranged from small to large for all the measured results. Conclusion These preliminary results suggest that WBV may potentially be a safe and feasible way to improve functional capacity in the 6MWT of patients with COPD undergoing a training program on the vibrating platform as well as in all domains of the SGRQ quality of life. However, further studies with a larger number of patients are needed to establish the long-term effect on functional capacity and quality of life in these patients. PMID:25624756
Predictors of change in life skills in schizophrenia after cognitive remediation.
Kurtz, Matthew M; Seltzer, James C; Fujimoto, Marco; Shagan, Dana S; Wexler, Bruce E
2009-02-01
Few studies have investigated predictors of response to cognitive remediation interventions in patients with schizophrenia. Predictor studies to date have selected treatment outcome measures that were either part of the remediation intervention itself or closely linked to the intervention with few studies investigating factors that predict generalization to measures of everyday life-skills as an index of treatment-related improvement. In the current study we investigated the relationship between four measures of neurocognitive function, crystallized verbal ability, auditory sustained attention and working memory, verbal learning and memory, and problem-solving, two measures of symptoms, total positive and negative symptoms, and the process variables of treatment intensity and duration, to change on a performance-based measure of everyday life-skills after a year of computer-assisted cognitive remediation offered as part of intensive outpatient rehabilitation treatment. Thirty-six patients with schizophrenia or schizoaffective disorder were studied. Results of a linear regression model revealed that auditory attention and working memory predicted a significant amount of the variance in change in performance-based measures of everyday life skills after cognitive remediation, even when variance for all other neurocognitive variables in the model was controlled. Stepwise regression revealed that auditory attention and working memory predicted change in everyday life-skills across the trial even when baseline life-skill scores, symptoms and treatment process variables were controlled. These findings emphasize the importance of sustained auditory attention and working memory for benefiting from extended programs of cognitive remediation.
Eccentric loading of microtensile specimens
NASA Technical Reports Server (NTRS)
Trapp, Mark A.
2004-01-01
Ceramic materials have a lower density than most metals and are capable of performing at extremely high temperatures. The utility of these materials is obvious; however, the fracture strength of brittle materials is not easily predicted and often varies greatly. Characteristically, brittle materials lack ductility and do not yield as other materials. Ceramics materials are naturally populated with microscopic cracks due to fabrication techniques. Upon application of a load, stress concentration occurs at the root of these cracks and fracture will eventually occur at some not easily predicted strength. In order to use ceramics in any application some design methodology must exist from which a component can be placed into service. This design methodology is CARES/LIFE (Ceramics Analysis and Reliability Evaluation of Structures) which has been developed and refined at NASA over the last several decades. The CARES/LIFE computer program predicts the probability of failure of a ceramic component over its service life. CARES combines finite element results from a commercial FE (finite element) package such as ANSYS and experimental results to compute the abovementioned probability of failure. Over the course of several tests CARES has had great success in predicting the life of various ceramic components and has been used throughout industry. The latest challenge is to verify that CARES is valid for MEMS (Micro-Electro Mechanical Systems). To investigate a series of microtensile specimens were fractured in the laboratory. From this data, material parameters were determined and used to predict a distribution of strength for other specimens that exhibit a known stress concentration. If the prediction matches the experimental results then these parameters can be applied to a desired component outside of the laboratory. During testing nearly half of the tensile Specimens fractured at a location that was not expected and hence not captured in the FE model. It has been my duty to investigate the nature of this phenomenon in hopes of finding a better correlation between theory and empirical results. To investigate I built complete FE models of all of the tensile specimens using ANSYS. It is suspected that some misalignment naturally occurs during testing and thus additional bending stresses are present in the specimens. I modeled this eccentric loading and ran several FE trials using ANSYS/PDS (a probabilistic design system in ANSYS). My objective this summer has been familiarize myself with the CARES/LIFE program in hopes of using it in conjunction with ANSYS to help verify that CARES is applicable to MEMS-scale (greater that 1 micron, less than 1 millimeter) components.
Mechanics Methodology for Textile Preform Composite Materials
NASA Technical Reports Server (NTRS)
Poe, Clarence C., Jr.
1996-01-01
NASA and its contractors have completed a program to develop a basic mechanics underpinning for textile composites. Three major deliverables were produced by the program: 1. A set of test methods for measuring material properties and design allowables; 2. Mechanics models to predict the effects of the fiber preform architecture and constituent properties on engineering moduli, strength, damage resistance, and fatigue life; and 3. An electronic data base of coupon type test data. This report describes these three deliverables.
Toward automated biochemotype annotation for large compound libraries.
Chen, Xian; Liang, Yizeng; Xu, Jun
2006-08-01
Combinatorial chemistry allows scientists to probe large synthetically accessible chemical space. However, identifying the sub-space which is selectively associated with an interested biological target, is crucial to drug discovery and life sciences. This paper describes a process to automatically annotate biochemotypes of compounds in a library and thus to identify bioactivity related chemotypes (biochemotypes) from a large library of compounds. The process consists of two steps: (1) predicting all possible bioactivities for each compound in a library, and (2) deriving possible biochemotypes based on predictions. The Prediction of Activity Spectra for Substances program (PASS) was used in the first step. In second step, structural similarity and scaffold-hopping technologies are employed. These technologies are used to derive biochemotypes from bioactivity predictions and the corresponding annotated biochemotypes from MDL Drug Data Report (MDDR) database. About a one million (982,889) commercially available compound library (CACL) has been tested using this process. This paper demonstrates the feasibility of automatically annotating biochemotypes for large libraries of compounds. Nevertheless, some issues need to be considered in order to improve the process. First, the prediction accuracy of PASS program has no significant correlation with the number of compounds in a training set. Larger training sets do not necessarily increase the maximal error of prediction (MEP), nor do they increase the hit structural diversity. Smaller training sets do not necessarily decrease MEP, nor do they decrease the hit structural diversity. Second, the success of systematic bioactivity prediction relies on modeling, training data, and the definition of bioactivities (biochemotype ontology). Unfortunately, the biochemotype ontology was not well developed in the PASS program. Consequently, "ill-defined" bioactivities can reduce the quality of predictions. This paper suggests the ways in which the systematic bioactivities prediction program should be improved.
Predictive Service Life Tests for Roofing Membranes
NASA Astrophysics Data System (ADS)
Bailey, David M.; Cash, Carl G.; Davies, Arthur G.
2002-09-01
The average service life of roofing membranes used in low-slope applications on U.S. Army buildings is estimated to be considerably shorter than the industry-presumed 20-year design life, even when installers carefully adhere to the latest guide specifications. This problem is due in large part to market-driven product development cycles, which do not include time for long-term field testing. To reduce delivery costs, contractors may provide untested, interior membranes in place of ones proven satisfactory in long-term service. Federal procurement regulations require that roofing systems and components be selected according to desired properties and generic type, not brand name. The problem is that a material certified to have satisfactory properties at installation time will not necessarily retain those properties in service. The overall objective of this research is to develop a testing program that can be executed in a matter of weeks to adequately predict a membrane's long-term performance in service. This report details accelerated aging tests of 12 popular membrane materials in the laboratory, and describes outdoor experiment stations set up for long-term exposure tests of those same membranes. The laboratory results will later be correlated with the outdoor test results to develop performance models and predictive service life tests.
Life prediction and constitutive models for engine hot section anisotropic materials
NASA Technical Reports Server (NTRS)
Swanson, G. A.; Linask, I.; Nissley, D. M.; Norris, P. P.; Meyer, T. G.; Walker, K. P.
1987-01-01
The results are presented of a program designed to develop life prediction and constitutive models for two coated single crystal alloys used in gas turbine airfoils. The two alloys are PWA 1480 and Alloy 185. The two oxidation resistant coatings are PWA 273, an aluminide coating, and PWA 286, an overlay NiCoCrAlY coating. To obtain constitutive and fatigue data, tests were conducted on uncoated and coated specimens loaded in the CH76 100 CH110 , CH76 110 CH110 , CH76 111 CH110 and CH76 123 CH110 crystallographic directions. Two constitutive models are being developed and evaluated for the single crystal materials: a micromechanic model based on crystallographic slip systems, and a macroscopic model which employs anisotropic tensors to model inelastic deformation anisotropy. Based on tests conducted on the overlay coating material, constitutive models for coatings also appear feasible and two initial models were selected. A life prediction approach was proposed for coated single crystal materials, including crack initiation either in the coating or in the substrate. The coating initiated failures dominated in the tests at load levels typical of gas turbine operation. Coating life was related to coating stress/strain history which was determined from specimen data using the constitutive models.
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.
2012-05-01
30 Figure 5.0.1 Phase II Analysis Process ...panel study the panel selection process followed a review of the outer skin environment investigated during the HTV-3X program which was suitable as...Subsequently, Panel 1B was down-selected from the screening process as it was observed to be subjected to stronger thermal field contributions due to fuel
Impact of active controls technology on structural integrity
NASA Technical Reports Server (NTRS)
Noll, Thomas; Austin, Edward; Donley, Shawn; Graham, George; Harris, Terry
1991-01-01
This paper summarizes the findings of The Technical Cooperation Program to assess the impact of active controls technology on the structural integrity of aeronautical vehicles and to evaluate the present state-of-the-art for predicting the loads caused by a flight-control system modification and the resulting change in the fatigue life of the flight vehicle. The potential for active controls to adversely affect structural integrity is described, and load predictions obtained using two state-of-the-art analytical methods are given.
Shearer, Heather M; Côté, Pierre; Boyle, Eleanor; Hayden, Jill A; Frank, John; Johnson, William G
2017-09-01
Purpose Our objective was to develop a clinical prediction model to identify workers with sustainable employment following an episode of work-related low back pain (LBP). Methods We used data from a cohort study of injured workers with incident LBP claims in the USA to predict employment patterns 1 and 6 months following a workers' compensation claim. We developed three sequential models to determine the contribution of three domains of variables: (1) basic demographic/clinical variables; (2) health-related variables; and (3) work-related factors. Multivariable logistic regression was used to develop the predictive models. We constructed receiver operator curves and used the c-index to measure predictive accuracy. Results Seventy-nine percent and 77 % of workers had sustainable employment at 1 and 6 months, respectively. Sustainable employment at 1 month was predicted by initial back pain intensity, mental health-related quality of life, claim litigation and employer type (c-index = 0.77). At 6 months, sustainable employment was predicted by physical and mental health-related quality of life, claim litigation and employer type (c-index = 0.77). Adding health-related and work-related variables to models improved predictive accuracy by 8.5 and 10 % at 1 and 6 months respectively. Conclusion We developed clinically-relevant models to predict sustainable employment in injured workers who made a workers' compensation claim for LBP. Inquiring about back pain intensity, physical and mental health-related quality of life, claim litigation and employer type may be beneficial in developing programs of care. Our models need to be validated in other populations.
2003-09-01
application .................................................. 5-42 5.10 Different materials within crack-block...5-30 Figure 5-29 - Application of required user edge node sets... applications . Users have at their disposal all of the capabilities within these finite element programs and may, if desired, include any number of
ERIC Educational Resources Information Center
Popham, W. James
2006-01-01
Scholastic Aptitude Test (SAT) and American College Program (ACT) scores are the main determinants of college entrance in the USA. It is widely assumed that these tests are predictive of success both during college and in later life, but such views are incorrect. Another widely-held view, held by many educators, is that the SAT and ACT are…
ERIC Educational Resources Information Center
Ritvo, Paul; Vora, Khushboo; Irvine, Jane; Mongrain, Myriam; Azargive, Saam; Azam, Muhammad Abid; Pirbaglou, Meysam; Guglietti, Crissa; Wayne, Noah; Perez, Daniel Felipe; Cribbie, Rob
2013-01-01
University education confronts students with stressful developmental challenges that can lead to mental health problems. Innovative programs must address an increasing prevalence of these problems but are impeded by the high costs involved. In this study, thirty-nine undergraduate students attended weekly one hour mindfulness meditation tutorials…
Chow, Esther O W; Ho, Henry C Y
2012-01-01
The rapidly ageing population in Hong Kong has led to a major concern in providing care for the elderly. Due to the current social changes in Hong Kong, such as smaller family size, longer life spans, and increasing employment demands, spouses increasingly serve as the primary caregivers for older adults. To explore the mental health of older spousal caregivers, this study investigated the relationships between psychological resources, social resources, and depression. One hundred fifty-eight spousal caregivers aged 55 and above were recruited from 13 caregiver resource centres in Hong Kong. Data were collected using structured questionnaires. Hierarchical regression analysis revealed that the number of duties and psychological resources including purpose in life, caregiver burden, and personal wellbeing explained 56% of the variance in depression. Logistic regression analysis further indicated that purpose in life predicted the likelihood of depression reported by caregivers. Social resources did not significantly predict depression. Results suggest that mental health enhancement programs should be developed for Chinese spousal caregivers with a focus on purpose in life, burden, and personal wellbeing.
Murphy, J Michael; Guzmán, Javier; McCarthy, Alyssa E; Squicciarini, Ana María; George, Myriam; Canenguez, Katia M; Dunn, Erin C; Baer, Lee; Simonsohn, Ariela; Smoller, Jordan W; Jellinek, Michael S
2015-04-01
The world's largest school-based mental health program, Habilidades para la Vida [Skills for Life (SFL)], has been operating on a national scale in Chile for 15 years. SFL's activities include using standardized measures to screen elementary school students and providing preventive workshops to students at risk for mental health problems. This paper used SFL's data on 37,397 students who were in first grade in 2009 and third grade in 2011 to ascertain whether first grade mental health predicted subsequent academic achievement and whether remission of mental health problems predicted improved academic outcomes. Results showed that mental health was a significant predictor of future academic performance and that, overall, students whose mental health improved between first and third grade made better academic progress than students whose mental health did not improve or worsened. Our findings suggest that school-based mental health programs like SFL may help improve students' academic outcomes.
Buffer thermal energy storage for an air Brayton solar engine
NASA Technical Reports Server (NTRS)
Strumpf, H. J.; Barr, K. P.
1981-01-01
The application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine was studied. To demonstrate the effect of buffer thermal energy storage on engine operation, a computer program was written which models the recuperator, receiver, and thermal storage device as finite-element thermal masses. Actual operating or predicted performance data are used for all components, including the rotating equipment. Based on insolation input and a specified control scheme, the program predicts the Brayton engine operation, including flows, temperatures, and pressures for the various components, along with the engine output power. An economic parametric study indicates that the economic viability of buffer thermal energy storage is largely a function of the achievable engine life.
Birth weight predicts aging trajectory: A hypothesis.
Vaiserman, Alexander M
2018-04-04
Increasing evidence suggests that risk for age-related disease and longevity can be programmed early in life. In human populations, convincing evidence has been accumulated indicating that intrauterine growth restriction (IUGR) resulting in low birth weight (<2.5 kg) followed by postnatal catch-up growth is associated with various aspects of metabolic syndrome, type 2 diabetes and cardiovascular disease in adulthood. Fetal macrosomia (birth weight > 4.5 kg), by contrast, is associated with high risk of non-diabetic obesity and cancers in later life. Developmental modification of epigenetic patterns is considered to be a central mechanism in determining such developmentally programmed phenotypes. Growth hormone/insulin-like growth factor (GH/IGF) axis is likely a key driver of these processes. In this review, evidence is discussed that suggests that different aging trajectories can be realized depending on developmentally programmed life-course dynamics of IGF-1. In this hypothetical scenario, IUGR-induced deficit of IGF-1 causes "diabetic" aging trajectory associated with various metabolic disorders in adulthood, while fetal macrosomia-induced excessive levels of IGF-1 lead to "cancerous" aging trajectory. If the above reasoning is correct, then both low and high birth weights are predictors of short life expectancy, while the normal birth weight is a predictor of "normal" aging and maximum longevity. Copyright © 2018 Elsevier B.V. All rights reserved.
Prediction of quantitative intrathoracic fluid volume to diagnose pulmonary oedema using LabVIEW.
Urooj, Shabana; Khan, M; Ansari, A Q; Lay-Ekuakille, Aimé; Salhan, Ashok K
2012-01-01
Pulmonary oedema is a life-threatening disease that requires special attention in the area of research and clinical diagnosis. Computer-based techniques are rarely used to quantify the intrathoracic fluid volume (IFV) for diagnostic purposes. This paper discusses a software program developed to detect and diagnose pulmonary oedema using LabVIEW. The software runs on anthropometric dimensions and physiological parameters, mainly transthoracic electrical impedance (TEI). This technique is accurate and faster than existing manual techniques. The LabVIEW software was used to compute the parameters required to quantify IFV. An equation relating per cent control and IFV was obtained. The results of predicted TEI and measured TEI were compared with previously reported data to validate the developed program. It was found that the predicted values of TEI obtained from the computer-based technique were much closer to the measured values of TEI. Six new subjects were enrolled to measure and predict transthoracic impedance and hence to quantify IFV. A similar difference was also observed in the measured and predicted values of TEI for the new subjects.
Health care expenditure and life expectancy in Australia: how well do we perform?
Taylor, R; Salkeld, G
1996-06-01
The Australian health care system consists of mixed public and private financing underpinned by Medicare, a universal government-run insurance scheme paid through taxation (and levy) on income. Australia has improved its ranking for life expectancy (at birth) since 1960, and in 1990 ranked ninth and seventh of 24 countries for females and males respectively; this is ahead of the United States and United Kingdom, and approximately equal to Canada. Australian hospital bed supply and utilisation are average, after deletion of day-only cases. The proportion of gross domestic product (GDP) spent on health, in relation to GDP per capita (adjusted for purchasing power), in Australia in 1990 was average, and the prices for health care from 1975 to 1990 did not increase when adjusted for inflation. Although 68 per cent of health expenditure emanates from public sources in Australia, this is lower than in the majority of European countries and Canada. Some countries are doing poorly (such as the United States, with lower than average life expectancy and higher than predicted health expenditure) and some countries are doing well (with higher than average life expectancy and lower than predicted health expenditure; for example, Japan). Australia has higher than average life expectancy and only slightly higher than predicted health expenditure per capita. Although the Australian system could be improved, there are no indications that radical changes are required. The relatively high life expectancy in Australia can be attributed to favourable social and economic conditions, successful public health programs, and the availability of universal quality health care.
Cost analysis of life support systems
NASA Technical Reports Server (NTRS)
Yakut, M. M.
1973-01-01
A methodology was developed to predict realistic relative cost of Life Support Systems (LSS) and to define areas of major cost impacts in the development cycle. Emphasis was given to tailoring the cost data for usage by program planners and designers. The equipment classifications used based on the degree of refinement were as follows: (1) Working model; (2) low-fidelity prototype; (3) high-fidelity prototype; and (4) flight-qualified system. The major advanced LSS evaluated included the following: (1) Carbon dioxide removal; (2) oxygen recovery systems; (3) water recovery systems; (4) atmosphere analysis system.
Thermal barrier coating life prediction model
NASA Technical Reports Server (NTRS)
Hillery, R. V.; Pilsner, B. H.; Cook, T. S.; Kim, K. S.
1986-01-01
This is the second annual report of the first 3-year phase of a 2-phase, 5-year program. The objectives of the first phase are to determine the predominant modes of degradation of a plasma sprayed thermal barrier coating system and to develop and verify life prediction models accounting for these degradation modes. The primary TBC system consists of an air plasma sprayed ZrO-Y2O3 top coat, a low pressure plasma sprayed NiCrAlY bond coat, and a Rene' 80 substrate. Task I was to evaluate TBC failure mechanisms. Both bond coat oxidation and bond coat creep have been identified as contributors to TBC failure. Key property determinations have also been made for the bond coat and the top coat, including tensile strength, Poisson's ratio, dynamic modulus, and coefficient of thermal expansion. Task II is to develop TBC life prediction models for the predominant failure modes. These models will be developed based on the results of thermmechanical experiments and finite element analysis. The thermomechanical experiments have been defined and testing initiated. Finite element models have also been developed to handle TBCs and are being utilized to evaluate different TBC failure regimes.
Climate warming causes life-history evolution in a model for Atlantic cod (Gadus morhua).
Holt, Rebecca E; Jørgensen, Christian
2014-01-01
Climate change influences the marine environment, with ocean warming being the foremost driving factor governing changes in the physiology and ecology of fish. At the individual level, increasing temperature influences bioenergetics and numerous physiological and life-history processes, which have consequences for the population level and beyond. We provide a state-dependent energy allocation model that predicts temperature-induced adaptations for life histories and behaviour for the North-East Arctic stock (NEA) of Atlantic cod (Gadus morhua) in response to climate warming. The key constraint is temperature-dependent respiratory physiology, and the model includes a number of trade-offs that reflect key physiological and ecological processes. Dynamic programming is used to find an evolutionarily optimal strategy of foraging and energy allocation that maximizes expected lifetime reproductive output given constraints from physiology and ecology. The optimal strategy is then simulated in a population, where survival, foraging behaviour, growth, maturation and reproduction emerge. Using current forcing, the model reproduces patterns of growth, size-at-age, maturation, gonad production and natural mortality for NEA cod. The predicted climate responses are positive for this stock; under a 2°C warming, the model predicted increased growth rates and a larger asymptotic size. Maturation age was unaffected, but gonad weight was predicted to more than double. Predictions for a wider range of temperatures, from 2 to 7°C, show that temperature responses were gradual; fish were predicted to grow faster and increase reproductive investment at higher temperatures. An emergent pattern of higher risk acceptance and increased foraging behaviour was also predicted. Our results provide important insight into the effects of climate warming on NEA cod by revealing the underlying mechanisms and drivers of change. We show how temperature-induced adaptations of behaviour and several life-history traits are not only mediated by physiology but also by trade-offs with survival, which has consequences for conservation physiology.
Climate warming causes life-history evolution in a model for Atlantic cod (Gadus morhua)
Holt, Rebecca E.; Jørgensen, Christian
2014-01-01
Climate change influences the marine environment, with ocean warming being the foremost driving factor governing changes in the physiology and ecology of fish. At the individual level, increasing temperature influences bioenergetics and numerous physiological and life-history processes, which have consequences for the population level and beyond. We provide a state-dependent energy allocation model that predicts temperature-induced adaptations for life histories and behaviour for the North-East Arctic stock (NEA) of Atlantic cod (Gadus morhua) in response to climate warming. The key constraint is temperature-dependent respiratory physiology, and the model includes a number of trade-offs that reflect key physiological and ecological processes. Dynamic programming is used to find an evolutionarily optimal strategy of foraging and energy allocation that maximizes expected lifetime reproductive output given constraints from physiology and ecology. The optimal strategy is then simulated in a population, where survival, foraging behaviour, growth, maturation and reproduction emerge. Using current forcing, the model reproduces patterns of growth, size-at-age, maturation, gonad production and natural mortality for NEA cod. The predicted climate responses are positive for this stock; under a 2°C warming, the model predicted increased growth rates and a larger asymptotic size. Maturation age was unaffected, but gonad weight was predicted to more than double. Predictions for a wider range of temperatures, from 2 to 7°C, show that temperature responses were gradual; fish were predicted to grow faster and increase reproductive investment at higher temperatures. An emergent pattern of higher risk acceptance and increased foraging behaviour was also predicted. Our results provide important insight into the effects of climate warming on NEA cod by revealing the underlying mechanisms and drivers of change. We show how temperature-induced adaptations of behaviour and several life-history traits are not only mediated by physiology but also by trade-offs with survival, which has consequences for conservation physiology. PMID:27293671
Stress and Coping as Predictors of Young Children's Development and Psychosocial Adjustment.
ERIC Educational Resources Information Center
Carson, David K.; Swanson, Dee M.
A total of 38 children of 5-6 years in one of four early childhood or kindergarten programs participated in a study of the predictive relationship of stress and coping to development and psychosocial adjustment. Measures of independent variables included the Life Events Scale for Children, Family Invulnerability Test, Hassles Scale for Children,…
ERIC Educational Resources Information Center
Benfari, Robert C.; Eaker, Elaine
1984-01-01
Studied male smokers (N=182) at high risk of coronary heart disease to determine variables that discriminated between successful and nonsuccessful quitters. Analysis revealed that baseline level of smoking, life events, personal security, and selected group process variables were predictive of success or failure in the intervention program.…
Guidelines for Migrant Infant and Toddler Day Care Programs.
ERIC Educational Resources Information Center
Birckmayer, Jennifer; Willis, Anne
Constant, unpredictable change is a condition of daily life for children of migrant workers; this factor affects much of the care that should be given them. Predictability in the child's daily experience with the same basic routines, toys, bed, and caretakers helps stabilize his world and allows him to build up experiences and make sense of them.…
Machinery health prognostics: A systematic review from data acquisition to RUL prediction
NASA Astrophysics Data System (ADS)
Lei, Yaguo; Li, Naipeng; Guo, Liang; Li, Ningbo; Yan, Tao; Lin, Jing
2018-05-01
Machinery prognostics is one of the major tasks in condition based maintenance (CBM), which aims to predict the remaining useful life (RUL) of machinery based on condition information. A machinery prognostic program generally consists of four technical processes, i.e., data acquisition, health indicator (HI) construction, health stage (HS) division, and RUL prediction. Over recent years, a significant amount of research work has been undertaken in each of the four processes. And much literature has made an excellent overview on the last process, i.e., RUL prediction. However, there has not been a systematic review that covers the four technical processes comprehensively. To fill this gap, this paper provides a review on machinery prognostics following its whole program, i.e., from data acquisition to RUL prediction. First, in data acquisition, several prognostic datasets widely used in academic literature are introduced systematically. Then, commonly used HI construction approaches and metrics are discussed. After that, the HS division process is summarized by introducing its major tasks and existing approaches. Afterwards, the advancements of RUL prediction are reviewed including the popular approaches and metrics. Finally, the paper provides discussions on current situation, upcoming challenges as well as possible future trends for researchers in this field.
Health promotion through employee assistance programs: a role for occupational therapists.
Maynard, M
1986-11-01
Health promotion is predicted to have a major impact on occupational therapy practice. Keeping people well and promoting a healthy life-style will be the focus for the future. Many companies and agencies are taking the lead by instituting employee assistance programs (EAPs). With the de-emphasis on long-term hospital care, many occupational therapists will be seeking employment with community health programs. This paper advocates a role for occupational therapists in health promotion and disease prevention in an EAP. A description of EAPs and the contributions that occupational therapists can make to these programs is offered. Practice and education considerations for occupational therapists' roles in EAPs are provided.
NASA Astrophysics Data System (ADS)
Nemeth, Noel N.; Jadaan, Osama M.; Palfi, Tamas; Baker, Eric H.
Brittle materials today are being used, or considered, for a wide variety of high tech applications that operate in harsh environments, including static and rotating turbine parts, thermal protection systems, dental prosthetics, fuel cells, oxygen transport membranes, radomes, and MEMS. Designing brittle material components to sustain repeated load without fracturing while using the minimum amount of material requires the use of a probabilistic design methodology. The NASA CARES/Life 1 (Ceramic Analysis and Reliability Evaluation of Structure/Life) code provides a general-purpose analysis tool that predicts the probability of failure of a ceramic component as a function of its time in service. This capability includes predicting the time-dependent failure probability of ceramic components against catastrophic rupture when subjected to transient thermomechanical loads (including cyclic loads). The developed methodology allows for changes in material response that can occur with temperature or time (i.e. changing fatigue and Weibull parameters with temperature or time). For this article an overview of the transient reliability methodology and how this methodology is extended to account for proof testing is described. The CARES/Life code has been modified to have the ability to interface with commercially available finite element analysis (FEA) codes executed for transient load histories. Examples are provided to demonstrate the features of the methodology as implemented in the CARES/Life program.
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.
Predictive Modeling of the CDRA 4BMS
NASA Technical Reports Server (NTRS)
Coker, Robert F.; Knox, James C.
2016-01-01
As part of NASA's Advanced Exploration Systems (AES) program and the Life Support Systems Project (LSSP), fully predictive models of the Four Bed Molecular Sieve (4BMS) of the Carbon Dioxide Removal Assembly (CDRA) on the International Space Station (ISS) are being developed. This virtual laboratory will be used to help reduce mass, power, and volume requirements for future missions. In this paper we describe current and planned modeling developments in the area of carbon dioxide removal to support future crewed Mars missions as well as the resolution of anomalies observed in the ISS CDRA.
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.
Impossible Predictions of the Unprecedented: Analogy, History, and the Work of Prognostication
NASA Astrophysics Data System (ADS)
Denning, Kathryn
At the beginning of exobiology and SETI as research programs circa 1960, it was reasonable and responsible for scientists and others to consider the potential effects of a detection of other life, or contact with it, upon humanity. It is no coincidence that this was a time of reckoning with the power of science and technology. The Cold War was settling in, space programs were beginning, and the technologies of war and those of discovery were then, as now, intertwined, in a way that made Carl Sagan, Philip Morrison, Joshua Lederberg, and others, concerned for humanity's future, and the future of life. Those concerns are as well-founded as ever. However, 50 years on, after half a century of predictions and untested hypotheses, we still only know that a detection of extraterrestrial life could come tomorrow, in the next century, or never. Many potential scenarios have been identified and explored, planetary protection protocols have been implemented for astrobiology, policy concerning SETI detections has been created and debated, and some valuable empirical work has been done concerning potential cultural reactions. We might now reasonably ask: what are our real goals here? And do they match what we are actually accomplishing? Are these exercises still beneficial, or are they reaching the point of diminishing returns? Might there be undesirable effects of prognostications about detection and contact? Elsewhere, I have discussed at some length what I think can sensibly be done to prepare for a detection. This leaves me with a further argument to make here: first, that the use of historical analogies of intercultural contact on Earth to predict or explore the potential consequences of contact with ETI may now be essentially useless or perhaps worse than useless; second, that the longstanding practice of prediction about contact now also invites scrutiny in terms of its utility; and third, that turning our attention to pressing topics at the intersection of astrobiology, SETI, and society, could be worthwhile for scholars of humanity.
NASA Astrophysics Data System (ADS)
Hellweg, C. E.; Spitta, L. F.; Kopp, K.; Schmitz, C.; Reitz, G.; Gerzer, R.
2016-01-01
Training young researchers in the field of space life sciences is essential to vitalize the future of spaceflight. In 2009, the DLR Institute of Aerospace Medicine established the Helmholtz Space Life Sciences Research School (SpaceLife) in cooperation with several universities, starting with 22 doctoral candidates. SpaceLife offered an intensive three-year training program for early-stage researchers from different fields (biology, biomedicine, biomedical engineering, physics, sports, nutrition, plant and space sciences). The candidates passed a multistep selection procedure with a written application, a self-presentation to a selection committee, and an interview with the prospective supervisors. The selected candidates from Germany as well as from abroad attended a curriculum taught in English. An overview of space life sciences was given in a workshop with introductory lectures on space radiation biology and dosimetry, space physiology, gravitational biology and astrobiology. The yearly Doctoral Students' Workshops were also interdisciplinary. During the first Doctoral Students' Workshop, every candidate presented his/her research topic including hypothesis and methods to be applied. The progress report was due after ∼1.5 years and a final report after ∼3 years. The candidates specialized in their subfield in advanced lectures, Journal Clubs, practical trainings, lab exchanges and elective courses. The students attended at least one transferable skills course per year, starting with a Research Skills Development course in the first year, a presentation and writing skills course in the second year, and a career and leadership course in the third year. The whole program encompassed 303 h and was complemented by active conference participation. In this paper, the six years' experience with this program is summarized in order to guide other institutions in establishment of structured Ph.D. programs in this field. The curriculum including elective courses is documented. The applicants' statistics revealed that personal contacts and the DLR website were most important the recruitment of doctoral candidates. The evaluation of the application and selection procedure revealed that prediction of thesis success based on master thesis mark or evaluation by the selection committee is difficult. SpaceLife Doctoral Students greatly contributed to the scientific output in terms of peer-reviewed publications of the Institute of Aerospace Medicine with a peak in the fourth year after start of the thesis and they continuously received awards for their scientific work.
Design and Operating Characteristics of High-Speed, Small-Bore, Angular-Contact Ball Bearings
NASA Technical Reports Server (NTRS)
Pinel, Stanley I.; Signer, Hans R.; Zaretsky, Erwin V.
1998-01-01
The computer program SHABERTH was used to analyze 35-mm-bore, angular-contact ball bearings designed and manufactured for high-speed turbomachinery applications. Parametric tests of the bearings were conducted on a high-speed, high-temperature bearing tester and were compared with the computer predictions. Four bearing and cage designs were studied. The bearings were lubricated either by jet lubrication or through the split inner ring with and without outer-ring cooling. The predicted bearing life decreased with increasing speed because of increased operating contact stresses caused by changes in contact angle and centrifugal load. For thrust loads only, the difference in calculated life for the 24 deg. and 30 deg. contact-angle bearings was insignificant. However, for combined loading, the 24 deg. contact-angle bearing gave longer life. For split-inner-ring bearings, optimal operating conditions were obtained with a 24 deg. contact angle and an inner-ring, land-guided cage, using outer-ring cooling in conjunction with low lubricant flow rates. Lower temperature and power losses were obtained with a single-outer-ring, land-guided cage for the 24 deg. contact-angle bearing having a relieved inner ring and partially relieved outer ring. Inner-ring temperatures were independent of lubrication mode and cage design. In comparison with measured values, reasonably good engineering correlation was obtained using the computer program SHABERTH for predicted bearing power loss and for inner- and outer-ring temperatures. The Parker formula for XCAV (used in SHABERTH, a measure of oil volume in the bearing cavity) may need to be refined to reflect bearing lubrication mode, cage design, and location of cage-controlling land.
Dong, Di; Tan-Koi, Wei-Chuen; Teng, Gim Gee; Finkelstein, Eric; Sung, Cynthia
2015-11-01
Allopurinol is an efficacious urate-lowering therapy (ULT), but is associated with rare serious adverse drug reactions of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with higher risk among HLA-B*5801 carriers. We assessed the cost-effectiveness of HLA-B*5801 testing, an enhanced safety program or strategies with both components. The analysis adopted a health systems perspective and considered Singaporean patients with chronic gout, over a lifetime horizon, using allopurinol or probenecid. The model incorporated SJS/TEN and gout treatment outcomes, allele frequencies, drug prices and other medical costs. Based on cost-effectiveness threshold of US$50,000 per quality-adjusted life year, HLA-B*5801-guided ULT selection or enhanced safety program was not cost effective. Avoidance of ULTs was the least preferred strategy as uncontrolled gout leads to lower quality-adjusted life years and higher costs. The analysis underscores the need for biomarkers with higher positive predictive value for SJS/TEN, less expensive genetic tests or safety programs, or more effective gout drugs. .
Beyond the Big Five: the role of extrinsic life aspirations in compulsive buying.
Otero-López, José M; Villardefrancos Pol, Estíbaliz; Castro Bolaño, Cristina
2017-11-01
The integration of units of differing natures which are found in different parts of some multilevel personality models is one of the most thought-provoking paths in contemporary research. In the field of compulsive buying, little is known about the interrelationships between the comparative and stable units such as personality traits (basic tendencies or Level I units) and goals (a kind of middle-level unit) which are more related to motivational processes and intentions governing people’s behavior. Self-reporting measures of compulsive buying, Big Five personality traits, and extrinsic life aspirations were administered to a general population sample consisting of 2,159 participants aged 15 to 65 (48.1% males; Mage= 35.4, SD= 13.24). Our results confirmed statistically significant associations with compulsive buying for the traits as well as the extrinsic goals. Furthermore, an important relationship between both levels in personality – traits vs . extrinsic life aspirations – was found. Finally, extrinsic life aspirations (specially, image, popularity, and conformity) contribute to the potentiation of the prediction of compulsive buying beyond the Five Factor Model. Current findings emphasize the advisability of considering both levels in personality, traits and middle-level units like life aspirations, not only in the prediction of compulsive buying, but also as potential targets for preventive and treatment programs.
Critical Life Prediction Research on Boron-Enhanced Ti-6A1-4V
2007-05-01
2.4 High Modulus Ti-6Al-2Fe-0.1Si-0.6B “T” Extrusions for HSCT program. Ref. Government Contract No. NASI -20220: High Speed Research-Airframe...0.1Si-0.6B “T” Extrusions for HSCT program. Ref. Government Contract No. NASI -20220: High Speed Research-Airframe Technology report. with the focus...baseline Ti-6Al-4V (Government Contract No. NASI -20220, High Speed Research-Airframe Technology Report, 1997: 3-5, 14, 26). 1 in 3 in 16 In
Thermal degradation of fire-retardant -treated wood : predicting residual service life
Jerrold E. Winandy
2001-01-01
This paper presents a review of more than 10 years of research on the effects of fire-retardant treatments on wood properties and the potential of these treatments for in-service degradation when exposed to elevated temperatures. It presents an in-depth discussion of the findings and implications of a major wood engineering research program to assess the current...
Accelerated test program for sealed nickel-cadmium spacecraft batteries/cells
NASA Technical Reports Server (NTRS)
Goodman, L. A.
1976-01-01
The feasibility was examined of inducing an accelerated test on sealed Nickel-Cadmium batteries or cells as a tool for spacecraft projects and battery users to determine: (1) the prediction of life capability; (2) a method of evaluating the effect of design and component changes in cells; and (3) a means of reducing time and cost of cell testing.
ERIC Educational Resources Information Center
Barabasch, Antje
2006-01-01
In this ever-changing economy, young adults must remain flexible and adaptable as they transition from school to work and plan their future life courses. It is difficult for today's youth to choose training programs which will guarantee them secure, long-term employment. As the future grows less predictable, greater uncertainty and risk are…
The Role of a School Library in a School's Reading Program
ERIC Educational Resources Information Center
Marcoux, Elizabeth; Loertscher, David V.
2009-01-01
As a foundational element of schooling, learning to read and reading to learn is every bit as important in the 21st century as it has ever been. Whether interacting online, doing assignments, taking tests, or social networking, the ability to read and read well affects every part of one's existence and often predicts success throughout life. In…
Yoshii, Hatsumi; Watanabe, Yuichiro; Kitamura, Hideaki; Nan, Zhang; Akazawa, Kouhei
2012-01-01
Early intervention in schizophrenia is important for patient prognosis and quality of life. At the time of the first episode, quality of life is influenced by identification of symptoms and by medical help-seeking behavior. In this prospective cohort study, we investigated help-seeking among 2690 parents of junior and senior high school students before and after the parents viewed a newly developed web-based education program aimed at improving knowledge of schizophrenia. Our web-based education program aimed to improve understanding of schizophrenia, including promotion of help-seeking. Many parents (33.1%-50.0%) consulted a physician in a department of psychosomatic medicine when their child experienced symptoms. Characteristics that predicted a decision not to seek psychiatric medical help were having child with all symptoms, younger parent age, and lower family income (p<0.05). After the education program, the rate of parents who sought medical help within 1 week was significantly higher for all symptom categories except sleeplessness (p=0.001). These findings suggest that the present web-based education program was useful in promoting medical help-seeking behavior among parents of junior and senior high school students in Japan. PMID:22980101
Advanced Software for Analysis of High-Speed Rolling-Element Bearings
NASA Technical Reports Server (NTRS)
Poplawski, J. V.; Rumbarger, J. H.; Peters, S. M.; Galatis, H.; Flower, R.
2003-01-01
COBRA-AHS is a package of advanced software for analysis of rigid or flexible shaft systems supported by rolling-element bearings operating at high speeds under complex mechanical and thermal loads. These loads can include centrifugal and thermal loads generated by motions of bearing components. COBRA-AHS offers several improvements over prior commercial bearing-analysis programs: It includes innovative probabilistic fatigue-life-estimating software that provides for computation of three-dimensional stress fields and incorporates stress-based (in contradistinction to prior load-based) mathematical models of fatigue life. It interacts automatically with the ANSYS finite-element code to generate finite-element models for estimating distributions of temperature and temperature-induced changes in dimensions in iterative thermal/dimensional analyses: thus, for example, it can be used to predict changes in clearances and thermal lockup. COBRA-AHS provides an improved graphical user interface that facilitates the iterative cycle of analysis and design by providing analysis results quickly in graphical form, enabling the user to control interactive runs without leaving the program environment, and facilitating transfer of plots and printed results for inclusion in design reports. Additional features include roller-edge stress prediction and influence of shaft and housing distortion on bearing performance.
Creep fatigue life prediction for engine hot section materials (isotropic)
NASA Technical Reports Server (NTRS)
Nelson, R. S.; Levan, G. W.; Harvey, P. R.
1992-01-01
This Final Report covers the activities completed under the optional program of the NASA HOST Contract, NAS3-23288. The initial effort of the optional program was report-in NASA CR189221, which consisted of high temperature strain controlled fatigue tests to study the effects of thermomechanical fatigue, multiaxial loading, reactive environments, and imposed stresses. The baseline alloy used in the tests included B1900+Hf (with or without coating) and wrought INCO 718. Tests conducted on B1900+Hf included environmental tests using various atmospheres (75 psig oxygen, purified argon, or block exposures) and specimen tests of wrought INCO 718 included tensile, creep, stress rupture, TMF, multiaxial, and mean stress tests. Results of these testings were used to calibrate a CDA model for INCO 718 alloy and to develop modifications or corrections to the CDA model to handle additional failure mechanisms. The Socie parameter was found to provide the best correlation for INCO multiaxial loading. Microstructural evaluations consisting of optical, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) techniques, and surface replication techniques to determine crack initiation lives provided data which were used to develop life prediction models.
Project STOP (Spectral Thermal Optimization Program)
NASA Technical Reports Server (NTRS)
Goldhammer, L. J.; Opjorden, R. W.; Goodelle, G. S.; Powe, J. S.
1977-01-01
The spectral thermal optimization of solar cell configurations for various solar panel applications is considered. The method of optimization depends upon varying the solar cell configuration's optical characteristics to minimize panel temperatures, maximize power output and decrease the power delta from beginning of life to end of life. Four areas of primary investigation are: (1) testing and evaluation of ultraviolet resistant coverslide adhesives, primarily FEP as an adhesive; (2) examination of solar cell absolute spectral response and corresponding cell manufacturing processes that affect it; (3) experimental work with solar cell manufacturing processes that vary cell reflectance (solar absorptance); and (4) experimental and theoretical studies with various coverslide filter designs, mainly a red rejection filter. The Hughes' solar array prediction program has been modified to aid in evaluating the effect of each of the above four areas on the output of a solar panel in orbit.
Bearing, gearing, and lubrication technology
NASA Technical Reports Server (NTRS)
Anderson, W. J.
1978-01-01
Results of selected NASA research programs on rolling-element and fluid-film bearings, gears, and elastohydrodynamic lubrication are reported. Advances in rolling-element bearing material technology, which have resulted in a significant improvement in fatigue life, and which make possible new applications for rolling bearings, are discussed. Research on whirl-resistant, fluid-film bearings, suitable for very high-speed applications, is discussed. An improved method for predicting gear pitting life is reported. An improved formula for calculating the thickness of elastohydrodynamic films (the existence of which help to define the operating regime of concentrated contact mechanisms such as bearings, gears, and cams) is described.
The role of disease management programs in the health behavior of chronically ill patients.
Cramm, Jane Murray; Adams, Samantha A; Walters, Bethany Hipple; Tsiachristas, Apostolos; Bal, Roland; Huijsman, Robbert; Rutten-Van Mölken, Maureen P M H; Nieboer, Anna Petra
2014-04-01
Investigate the effects of disease management program (DMP) implementation on physical activity, smoking, and physical quality of life among chronically ill patients. This study used a mixed-methods approach involving qualitative (35 interviews with project managers) and quantitative (survey of patients from 18 DMPs) data collection. Questionnaire response rates were 51% (2010; 2619/5108) at T0 and 47% (2011; 2191/4693) at T1. Physical activity and the percentage of smokers improved significantly over time, whereas physical quality of life declined. After adjusting for patients' physical quality of life at T0, age, educational level, marital status, and gender, physical activity at T0 (p<0.01), changes in physical activity (p<0.001), and percentage of smokers at T0 (p<0.05) predicted physical quality of life at T1. Project managers reported that DMPs improved patient-professional interaction. The ability to set more concrete targets improved patients' health behaviors. DMPs appear to improve physical activity among chronically ill patients over time. Furthermore, (changes in) health behavior are important for the physical quality of life of chronically ill patients. Redesigning care systems and implementing DMPs based on the chronic care model may improve health behavior among chronically ill patients. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
An Update on the Lithium-Ion Cell Low-Earth-Orbit Verification Test Program
NASA Technical Reports Server (NTRS)
Reid, Concha M.; Manzo, Michelle A.; Miller, Thomas B.; McKissock, Barbara I.; Bennett, William
2007-01-01
A Lithium-Ion Cell Low-Earth-Orbit Verification Test Program is being conducted by NASA Glenn Research Center to assess the performance of lithium-ion (Li-ion) cells over a wide range of low-Earth-orbit (LEO) conditions. The data generated will be used to build an empirical model for Li-ion batteries. The goal of the modeling will be to develop a tool to predict the performance and cycle life of Li-ion batteries operating at a specified set of mission conditions. Using this tool, mission planners will be able to design operation points of the battery system while factoring in mission requirements and the expected life and performance of the batteries. Test conditions for the program were selected via a statistical design of experiments to span a range of feasible operational conditions for LEO aerospace applications. The variables under evaluation are temperature, depth-of-discharge (DOD), and end-of-charge voltage (EOCV). The baseline matrix was formed by generating combinations from a set of three values for each variable. Temperature values are 10 C, 20 C and 30 C. Depth-of-discharge values are 20%, 30% and 40%. EOCV values are 3.85 V, 3.95 V, and 4.05 V. Test conditions for individual cells may vary slightly from the baseline test matrix depending upon the cell manufacturer s recommended operating conditions. Cells from each vendor are being evaluated at each of ten sets of test conditions. Cells from four cell manufacturers are undergoing life cycle tests. Life cycling on the first sets of cells began in September 2004. These cells consist of Saft 40 ampere-hour (Ah) cells and Lith ion 30 Ah cells. These cells have achieved over 10,000 cycles each, equivalent to about 20 months in LEO. In the past year, the test program has expanded to include the evaluation of Mine Safety Appliances (MSA) 50 Ah cells and ABSL battery modules. The MSA cells will begin life cycling in October 2006. The ABSL battery modules consist of commercial Sony hard carbon 18650 lithium-ion cells configured in series and parallel combinations to create nominal 14.4 volt, 3 Ah packs (4s-2p). These modules have accumulated approximately 3000 cycles. Results on the performance of the cells and modules will be presented in this paper. The life prediction and performance model for Li-ion cells in LEO will be built by analyzing the data statistically and performing regression analysis. Cells are being cycled to failure so that differences in performance trends that occur at different stages in the life of the cell can be observed and accurately modeled. Cell testing is being performed at the Naval Surface Warfare Center in Crane, IN.
Composite Overwrapped Pressure Vessel (COPV) Stress Rupture Testing
NASA Technical Reports Server (NTRS)
Greene, Nathanael J.; Saulsberry, Regor L.; Leifeste, Mark R.; Yoder, Tommy B.; Keddy, Chris P.; Forth, Scott C.; Russell, Rick W.
2010-01-01
This paper reports stress rupture testing of Kevlar(TradeMark) composite overwrapped pressure vessels (COPVs) at NASA White Sands Test Facility. This 6-year test program was part of the larger effort to predict and extend the lifetime of flight vessels. Tests were performed to characterize control parameters for stress rupture testing, and vessel life was predicted by statistical modeling. One highly instrumented 102-cm (40-in.) diameter Kevlar(TradeMark) COPV was tested to failure (burst) as a single-point model verification. Significant data were generated that will enhance development of improved NDE methods and predictive modeling techniques, and thus better address stress rupture and other composite durability concerns that affect pressure vessel safety, reliability and mission assurance.
Rolling Bearing Life Prediction-Past, Present, and Future
NASA Technical Reports Server (NTRS)
Zaretsky, E V; Poplawski, J. V.; Miller, C. R.
2000-01-01
Comparisons were made between the life prediction formulas of Lundberg and Palmgren, Ioannides and Harris, and Zaretsky and full-scale ball and roller bearing life data. The effect of Weibull slope on bearing life prediction was determined. Life factors are proposed to adjust the respective life formulas to the normalized statistical life distribution of each bearing type. The Lundberg-Palmgren method resulted in the most conservative life predictions compared to Ioannides and Harris, and Zaretsky methods which produced statistically similar results. Roller profile can have significant effects on bearing life prediction results. Roller edge loading can reduce life by as much as 98 percent. The resultant predicted life not only depends on the life equation used but on the Weibull slope assumed, the least variation occurring with the Zaretsky equation. The load-life exponent p of 10/3 used in the American National Standards Institute (ANSI)/American Bearing Manufacturers Association (ABMA)/International Organization for Standardization (ISO) standards is inconsistent with the majority roller bearings designed and used today.
Family predictors of parent participation in an adolescent drug abuse prevention program.
Al-Halabi Díaz, Susana; Secades-Villa, Roberto; Pérez, José Manuel Errasti; Fernández-Hermida, José Ramón; García-Rodríguez, Olaya; Crespo, José Luis Carballo
2006-07-01
Low participation rates constitute a serious problem faced by family drug abuse prevention programs. In this study we analyse the factors related to participation in a Life Skills Training program implemented in three schools in Spain. Participants in the study were 485 pupils aged 12 - 14 years and their respective parents. The variables that predicted participation in the program were: number of children and educational level of parents, children's drug use, family conflict, parental rearing style, relationships between parents and children and family communication. The results from Spain are similar to those found in international studies, and indicate that the families most at risk of drug use are those least likely to participate in prevention programs. There is a need for strategies to increase participation in prevention programs of the families most at risk.
Murphy, J. Michael; Guzmán, Javier; McCarthy, Alyssa; Squicciarini, Ana María; George, Myriam; Canenguez, Katia; Dunn, Erin C.; Baer, Lee; Simonsohn, Ariela; Smoller, Jordan W.; Jellinek, Michael
2015-01-01
The world’s largest school-based mental health program, Habilidades para la Vida [Skills for Life, SFL], has been operating at a national scale in Chile for fifteen years. SFL’s activities include using standardized measures to screen elementary school students and providing preventive workshops to students at risk for mental health problems. This paper used SFL’s data on 37,397 students who were in first grade in 2009 and third grade in 2011 to ascertain whether first grade mental health predicted subsequent academic achievement and whether remission of mental health problems predicted improved academic outcomes. Results showed that mental health was a significant predictor of future academic performance and that, overall, students whose mental health improved between first and third grade made better academic progress than students whose mental health did not improve or worsened. Our findings suggest that school-based mental health programs like SFL may help improve students’ academic outcomes. PMID:24771270
Daskalakis, Nikolaos P.; Bagot, Rosemary C.; Parker, Karen J.; Vinkers, Christiaan H.; de Kloet, E. R.
2013-01-01
Stressful experiences during early-life can modulate the genetic programming of specific brain circuits underlying emotional and cognitive aspects of behavioral adaptation to stressful experiences later in life. Although this programming effect exerted by experience-related factors is an important determinant of mental health, its outcome depends on cognitive inputs and hence the valence an individual assigns to a given environmental context. From this perspective we will highlight, with studies in rodents, non-human primates and humans, the three-hit concept of vulnerability and resilience to stress-related mental disorders, which is based on gene-environment interactions during critical phases of perinatal and juvenile brain development. The three-hit (i.e., hit-1: genetic predisposition, hit-2: early-life environment, and hit-3: later-life environment) concept accommodates the cumulative stress hypothesis stating that in a given context vulnerability is enhanced when failure to cope with adversity accumulates. Alternatively, the concept also points to the individual’s predictive adaptive capacity, which underlies the stress inoculation and match/mismatch hypotheses. The latter hypotheses propose that the experience of relatively mild early-life adversity prepares for the future and promotes resilience to similar challenges in later-life; when a mismatch occurs between early and later-life experience, coping is compromised and vulnerability is enhanced. The three-hit concept is fundamental for understanding how individuals can either be prepared for coping with life to come and remain resilient or are unable to do so and succumb to a stress-related mental disorder, under seemingly identical circumstances. PMID:23838101
Daskalakis, Nikolaos P; Bagot, Rosemary C; Parker, Karen J; Vinkers, Christiaan H; de Kloet, E R
2013-09-01
Stressful experiences during early-life can modulate the genetic programming of specific brain circuits underlying emotional and cognitive aspects of behavioral adaptation to stressful experiences later in life. Although this programming effect exerted by experience-related factors is an important determinant of mental health, its outcome depends on cognitive inputs and hence the valence an individual assigns to a given environmental context. From this perspective we will highlight, with studies in rodents, non-human primates and humans, the three-hit concept of vulnerability and resilience to stress-related mental disorders, which is based on gene-environment interactions during critical phases of perinatal and juvenile brain development. The three-hit (i.e., hit-1: genetic predisposition, hit-2: early-life environment, and hit-3: later-life environment) concept accommodates the cumulative stress hypothesis stating that in a given context vulnerability is enhanced when failure to cope with adversity accumulates. Alternatively, the concept also points to the individual's predictive adaptive capacity, which underlies the stress inoculation and match/mismatch hypotheses. The latter hypotheses propose that the experience of relatively mild early-life adversity prepares for the future and promotes resilience to similar challenges in later-life; when a mismatch occurs between early and later-life experience, coping is compromised and vulnerability is enhanced. The three-hit concept is fundamental for understanding how individuals can either be prepared for coping with life to come and remain resilient or are unable to do so and succumb to a stress-related mental disorder, under seemingly identical circumstances. Copyright © 2013 Elsevier Ltd. All rights reserved.
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.
Outcomes and lessons learned from evaluating TRICARE's disease management programs.
Dall, Timothy M; Askarinam Wagner, Rachel C; Zhang, Yiduo; Yang, Wenya; Arday, David R; Gantt, Cynthia J
2010-06-01
To share outcomes and lessons learned from an evaluation of disease management (DM) programs for asthma, congestive heart failure (CHF), and diabetes for TRICARE patients. Multiyear evaluation of participants in voluntary, opt-out DM programs. Patient-centered programs, administered by 3 regional contractors, provide phone-based consultations with a care manager, educational materials, and newsletters. The study sample consisted of 23,793 asthma, 4092 CHF, and 29,604 diabetes patients with at least 6 months' tenure in the program. Medical claims were analyzed to quantify program effect on healthcare utilization, medical costs, and clinical outcomes. Multivariate regression analysis with an historical control group was used to predict patient outcomes in the absence of DM. The difference between actual and predicted DM patient outcomes was attributed to the program. A patient survey collected data on program satisfaction and perceived usefulness of program information and services. Modest improvements in patient outcomes included reduced inpatient days and medical costs, and (with few exceptions) increased percentages of patients receiving appropriate medications and tests. Annual per patient reductions in medical costs were $453, $371, and $783 for asthma, CHF, and diabetes program participants, respectively. The estimated return on investment was $1.26 per $1.00 spent on DM services. Findings suggest that the DM programs more than pay for themselves, in addition to improving patient health and quality of life. Lessons learned in program design, implementation, effectiveness, and evaluation may benefit employers contemplating DM, DM providers, and evaluators of DM programs.
NASA Technical Reports Server (NTRS)
Richey, Edward, III
1995-01-01
This research aims to develop the methods and understanding needed to incorporate time and loading variable dependent environmental effects on fatigue crack propagation (FCP) into computerized fatigue life prediction codes such as NASA FLAGRO (NASGRO). In particular, the effect of loading frequency on FCP rates in alpha + beta titanium alloys exposed to an aqueous chloride solution is investigated. The approach couples empirical modeling of environmental FCP with corrosion fatigue experiments. Three different computer models have been developed and incorporated in the DOS executable program. UVAFAS. A multiple power law model is available, and can fit a set of fatigue data to a multiple power law equation. A model has also been developed which implements the Wei and Landes linear superposition model, as well as an interpolative model which can be utilized to interpolate trends in fatigue behavior based on changes in loading characteristics (stress ratio, frequency, and hold times).
NASA Technical Reports Server (NTRS)
Thesken, John C.; Bowman, Cheryl L.; Arnold, Steven M.
2003-01-01
Successful spaceflight operations require onboard power management systems that reliably achieve mission objectives for a minimal launch weight. Because of their high specific energies and potential for reduced maintenance and logistics, composite flywheels are an attractive alternative to electrochemical batteries. The Rotor Durability Team, which comprises members from the Ohio Aerospace Institute (OAI) and the NASA Glenn Research Center, completed a program of elevated temperature testing at Glenn' s Life Prediction Branch's Fatigue Laboratory. The experiments provided unique design data essential to the safety and durability of flywheel energy storage systems for the International Space Station and other manned spaceflight applications. Analysis of the experimental data (ref. 1) demonstrated that the compressive stress relaxation of composite flywheel rotor material is significantly greater than the commonly available tensile stress relaxation data. Durability analysis of compression preloaded flywheel rotors is required for accurate safe-life predictions for use in the International Space Station.
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.
Development of Testing Methodologies for the Mechanical Properties of MEMS
NASA Technical Reports Server (NTRS)
Ekwaro-Osire, Stephen
2003-01-01
This effort is to investigate and design testing strategies to determine the mechanical properties of MicroElectroMechanical Systems (MEMS) as well as investigate the development of a MEMS Probabilistic Design Methodology (PDM). One item of potential interest is the design of a test for the Weibull size effect in pressure membranes. The Weibull size effect is a consequence of a stochastic strength response predicted from the Weibull distribution. Confirming that MEMS strength is controlled by the Weibull distribution will enable the development of a probabilistic design methodology for MEMS - similar to the GRC developed CARES/Life program for bulk ceramics. However, the primary area of investigation will most likely be analysis and modeling of material interfaces for strength as well as developing a strategy to handle stress singularities at sharp corners, filets, and material interfaces. This will be a continuation of the previous years work. The ultimate objective of this effort is to further develop and verify the ability of the Ceramics Analysis and Reliability Evaluation of Structures Life (CARES/Life) code to predict the time-dependent reliability of MEMS structures subjected to multiple transient loads.
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.
Defense Acquisitions: Assessments of Selected Weapon Programs
2013-03-01
UHF) Follow-On ( UFO ) satellite system currently in operation and provide interoperability with legacy terminals. MUOS consists of a network of...MUOS satellites remain important due to the past operational failures of two UFO satellites and predicted end-of-life of on-orbit UFO satellites...Despite the delay and earlier, unexpected failures of two UFO satellites, the required availability level of UHF communication capabilities has been
Development Program for Field-Repairable/Expendable Main Rotor Blades
1976-09-01
honeycomb aft 2, and it represents the most cost- core, and extruded aluminum alloy effective approach to a repairable trailing-edge spline (Reference...materials lend themselves to relatively inexpensive fabrication techniques, the questionable torsional stiffness of composite spars eliminated them...values of the fatigue strength of aluminum , the spline and aft doublers are predicted to have a negative margin of safety for infinite life. The
Ceramic Life Prediction Methodology.
1986-03-01
stress rupture data were collected on two materials, a sintered silicon nitride and a lithium-aluminum-silicate. The fast fracture data was presented...graphically in the form of Weibull plots of percent failed versus failure stress . The stress rupture results were presented in tabular form. Photo...micrographs were presented to illustrate the fracture surfaces of fast fracture and stress rupture failures. A program of specimen development was coaducted
Composite structural materials
NASA Technical Reports Server (NTRS)
Loewy, Robert G.; Wiberley, Stephen E.
1988-01-01
A decade long program to develop critical advanced composite technology in the areas of physical properties, structural concept and analysis, manufacturing, reliability, and life predictions is reviewed. Specific goals are discussed. The status of the chemical vapor deposition effects on carbon fiber properties; inelastic deformation of metal matrix laminates; fatigue damage in fibrous MMC laminates; delamination fracture toughness in thermoplastic matrix composites; and numerical analysis of composite micromechanical behavior are presented.
ERIC Educational Resources Information Center
Graham, Anne
2004-01-01
The experience of loss can place children and young people in a vulnerable position as it affects their development and overall emotional and social wellbeing. The experience of loss can markedly influence young people's perceptions of themselves and their world. They may not trust the predictability of events, their self-image may be damaged,…
Multiaxial Fatigue Damage Parameter and Life Prediction without Any Additional Material Constants
Yu, Zheng-Yong; Liu, Qiang; Liu, Yunhan
2017-01-01
Based on the critical plane approach, a simple and efficient multiaxial fatigue damage parameter with no additional material constants is proposed for life prediction under uniaxial/multiaxial proportional and/or non-proportional loadings for titanium alloy TC4 and nickel-based superalloy GH4169. Moreover, two modified Ince-Glinka fatigue damage parameters are put forward and evaluated under different load paths. Results show that the generalized strain amplitude model provides less accurate life predictions in the high cycle life regime and is better for life prediction in the low cycle life regime; however, the generalized strain energy model is relatively better for high cycle life prediction and is conservative for low cycle life prediction under multiaxial loadings. In addition, the Fatemi–Socie model is introduced for model comparison and its additional material parameter k is found to not be a constant and its usage is discussed. Finally, model comparison and prediction error analysis are used to illustrate the superiority of the proposed damage parameter in multiaxial fatigue life prediction of the two aviation alloys under various loadings. PMID:28792487
Multiaxial Fatigue Damage Parameter and Life Prediction without Any Additional Material Constants.
Yu, Zheng-Yong; Zhu, Shun-Peng; Liu, Qiang; Liu, Yunhan
2017-08-09
Based on the critical plane approach, a simple and efficient multiaxial fatigue damage parameter with no additional material constants is proposed for life prediction under uniaxial/multiaxial proportional and/or non-proportional loadings for titanium alloy TC4 and nickel-based superalloy GH4169. Moreover, two modified Ince-Glinka fatigue damage parameters are put forward and evaluated under different load paths. Results show that the generalized strain amplitude model provides less accurate life predictions in the high cycle life regime and is better for life prediction in the low cycle life regime; however, the generalized strain energy model is relatively better for high cycle life prediction and is conservative for low cycle life prediction under multiaxial loadings. In addition, the Fatemi-Socie model is introduced for model comparison and its additional material parameter k is found to not be a constant and its usage is discussed. Finally, model comparison and prediction error analysis are used to illustrate the superiority of the proposed damage parameter in multiaxial fatigue life prediction of the two aviation alloys under various loadings.
Modeling the response of native steelhead to hatchery supplementation programs in an Idaho River
Byrne, Alan; Bjornn, T.C.; McIntyre, J.D.
1993-01-01
A life history model was used to predict the response of native steelhead Oncorhynchus mykiss in the Lochsa River, Idaho, to long-term supplementation with hatchery fry and smolts. The four key factors affecting the response of the native fish to a stocking program were (1) the number of native spawners, (2) the number of stocked fish, (3) the number and fitness of progeny from stocked fish, and (4) the amount of mating between hatchery and native fish. Long-term stocking of fry or smolts led to the extinction of native fish in some scenarios. The model can be used to help assess the risks and benefits of proposed stocking programs.
Life prediction and constitutive behavior
NASA Technical Reports Server (NTRS)
Halford, G. R.
1983-01-01
One of the primary drivers that prompted the initiation of the hot section technology (HOST) program was the recognized need for improved cyclic durability of costly hot section components. All too frequently, fatigue in one form or another was directly responsible for the less than desired durability, and prospects for the future weren't going to improve unless a significant effort was mounted to increase our knowledge and understanding of the elements governing cyclic crack initiation and propagation lifetime. Certainly one of the important factors is the ability to perform accurate structural stress-strain analyses on a routine basis to determine the magnitudes of the localized stresses and strains since it is these localized conditions that govern the initiation and crack growth processes. Developing the ability to more accurately predict crack initiation lifetimes and cyclic crack growth rates for the complex loading conditions found in turbine engine hot sections is of course the ultimate goal of the life prediction research efforts. It has been found convenient to divide the research efforts into those dealing with nominally isotropic and anisotropic alloys; the latter for application to directionally solidified and single crystal turbine blades.
Progress of Ongoing NASA Lithium-Ion Cell Verification Testing for Aerospace Applications
NASA Technical Reports Server (NTRS)
McKissock, Barbara I.; Manzo, Michelle A.; Miller, Thomas B.; Reid, Concha M.; Bennett, William R.; Gemeiner, Russel
2008-01-01
A Lithium-ion Verification and Validation Program with the purpose to assess the capabilities of current aerospace lithium-ion (Li-ion) battery cells to perform in a low-earth-orbit (LEO) regime was initiated in 2002. This program involves extensive characterization and LEO life testing at ten different combinations of depth-of-discharge, temperature, and end-of-charge voltage. The test conditions selected for the life tests are defined as part of a statistically designed test matrix developed to determine the effects of operating conditions on performance and life of Li-ion cells. Results will be used to model and predict cell performance and degradation as a function of test operating conditions. Testing is being performed at the Naval Surface Warfare Center/Crane Division in Crane, Indiana. Testing was initiated in September 2004 with 40 Ah cells from Saft and 30 Ah cells from Lithion. The test program has been expanded with the addition of modules composed of 18650 cells from ABSL Power Solutions in April 2006 and the addition of 50 Ah cells from Mine Safety Appliances Co. (MSA) in June 2006. Preliminary results showing the average voltage and average available discharge capacity for the Saft and Lithion packs at the test conditions versus cycles are presented.
Sansó, Noemí; Galiana, Laura; Oliver, Amparo; Pascual, Antonio; Sinclair, Shane; Benito, Enric
2015-08-01
Professionals working in the landscape of death and dying frequently are exposed to existential issues, psychological challenges, and emotional distress associated with care at the end of life. Identifying factors that help professionals cope with frequent exposure to issues related to mortality could enhance palliative care providers' and patients' quality of life. To improve our understanding of the factors associated with professionals' inner life, through the assessment of an adapted version of Kearney and Kearney's awareness model of self-care. The main assumptions of the study were that competence in coping with death and awareness would be positively related to compassion satisfaction and negatively to compassion fatigue and burnout; moreover, participating in a specific training program aimed at facing suffering and death, and self-care would positively predict coping with death. A cross-sectional online survey of Spanish palliative care professionals was conducted through the member e-mail list of the Spanish Society of Palliative Care. A total of 387 professionals completed the survey, which included demographic data, and personal and professional scales on the mentioned constructs. Data fit reasonably well with the estimated model. Whereas the hypothesis relating spiritual training to coping with death was not supported by the data, all other aspects of the hypotheses were supported, namely self-care and awareness positively predicted professionals' competence in coping with death, and this, together with awareness, positively predicted compassion satisfaction and negatively predict compassion fatigue and burnout. The awareness-based model of self-care was successfully tested in a multidisciplinary sample of Spanish palliative care professionals. This research applies a quantitative evaluation of the model, providing evidence of a constellation of key variables for health professionals' quality of life, such as specific training, self-care, awareness and coping with death competency. Copyright © 2015 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.
Generation of long time creep data on refractory alloys at elevated temperatures
NASA Technical Reports Server (NTRS)
Sheffler, K. D.
1970-01-01
Creep tests were conducted on two tantalum alloys (ASTAR 811C and T-111 alloy), on a molybdenum alloy (TZM), and on CVD tungsten. The T-111 alloy 1% creep life data have been subjected to Manson's station function analysis, and the progress on this analysis is described. In another test program, the behavior of T-111 alloy with continuously varying temperatures and stresses has been studied. The results indicated that the previously described analysis predicts the observed creep behavior with reasonable accuracy. In addition to the T-111 test program, conventional 1% creep life data have been obtained for ASTAR 811C alloy. Previously observed effects of heat treatment on the creep strength of this material have been discussed and a model involving carbide strengthening primarily at the grain boundaries, rather than in a classical dispersion hardening mechanism, has been proposed to explain the observed results.
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.
Bedoukian, Matthew A.; Rodriguez, Sarah M.; Cohen, Matthew B.; Duncan Smith, Stuart V.; Park, Jennifer
2009-01-01
Gene expression in Drosophila melanogaster changes significantly throughout life and some of these changes can be delayed by lowering ambient temperature and also by dietary restriction. These two interventions are known to slow the rate of aging as well as the accumulation of damage. It is unknown, however, whether gene expression changes that occur during development and early adult life make an animal more vulnerable to death. Here we develop a method capable of measuring the rate of programmed genetic changes during young adult life in Drosophila melanogaster and show that these changes can be delayed or accelerated in a manner that is predictive of longevity. We show that temperature shifts and dietary restriction, which slow the rate of aging in Drosophila melanogaster, extend the window of neuronal susceptibility to GRIM over-expression in a way that scales to lifespan. We propose that this susceptibility can be used to test compounds and genetic manipulations that alter the onset of senescence by changing the programmed timing of gene expression that correlates and may be causal to aging. PMID:19428445
Proposed comprehensive ototoxicity monitoring program for VA healthcare (COMP-VA)
Konrad-Martin, Dawn; Reavis, Kelly M.; McMillan, Garnett; Helt, Wendy J.; Dille, Marilyn
2015-01-01
Prevention and rehabilitation of hearing loss and tinnitus, the two most commonly awarded service-connected disabilities, are high priority initiatives in the Department of Veterans Affairs (VA). At least 4,000 Veterans, most with significant hearing loss, will receive cisplatin this year, with more than half sustaining permanent hearing shift and nearly 40% developing new tinnitus. With improved survivability following cancer treatment, Veterans treated with cisplatin are approached with the dual goals of effective treatment and preserved quality of life. This article describes COMP-VA, a comprehensive ototoxicity monitoring program developed for VA patients receiving cisplatin. The program includes an individualized pretreatment prediction model that identifies the likelihood of hearing shift given cisplatin dose and patient factors. It supports both manual and automated hearing testing with a newly developed portable audiometer capable of performing the recommended procedures on the chemotherapy unit during treatment. It also includes objective methods for identifying outer hair cell changes and predicting audiogram changes using distortion-product otoacoustic emissions. We describe this program of evidence-based ototoxicity monitoring protocols using a case example to give the reader an understanding of how this program would be applied, along with a plan for future work to accomplish the final stages of program development. PMID:24805896
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Bednarcyk, Brett A.; Pineda, Evan J.; Walton, Owen J.; Arnold, Steven M.
2016-01-01
Stochastic-based, discrete-event progressive damage simulations of ceramic-matrix composite and polymer matrix composite material structures have been enabled through the development of a unique multiscale modeling tool. This effort involves coupling three independently developed software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/ Life), and (3) the Abaqus finite element analysis (FEA) program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating unit cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC. Abaqus is used at the global scale to model the overall composite structure. An Abaqus user-defined material (UMAT) interface, referred to here as "FEAMAC/CARES," was developed that enables MAC/GMC and CARES/Life to operate seamlessly with the Abaqus FEA code. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events, which incrementally progress and lead to ultimate structural failure. This report describes the FEAMAC/CARES methodology and discusses examples that illustrate the performance of the tool. A comprehensive example problem, simulating the progressive damage of laminated ceramic matrix composites under various off-axis loading conditions and including a double notched tensile specimen geometry, is described in a separate report.
Heckman, James J; Kautz, Tim
2012-08-01
This paper summarizes recent evidence on what achievement tests measure; how achievement tests relate to other measures of "cognitive ability" like IQ and grades; the important skills that achievement tests miss or mismeasure, and how much these skills matter in life. Achievement tests miss, or perhaps more accurately, do not adequately capture, soft skills -personality traits, goals, motivations, and preferences that are valued in the labor market, in school, and in many other domains. The larger message of this paper is that soft skills predict success in life, that they causally produce that success, and that programs that enhance soft skills have an important place in an effective portfolio of public policies.
Uncertainty Considerations for Ballistic Limit Equations
NASA Technical Reports Server (NTRS)
Schonberg, W. P.; Evans, H. J.; Williamsen, J. E; Boyer, R. L.; Nakayama, G. S.
2005-01-01
The overall risk for any spacecraft system is typically determined using a Probabilistic Risk Assessment (PRA). A PRA determines the overall risk associated with a particular mission by factoring in all known risks to the spacecraft during its mission. The threat to mission and human life posed by the micro-meteoroid and orbital debris (MMOD) environment is one of the risks. NASA uses the BUMPER II program to provide point estimate predictions of MMOD risk for the Space Shuttle and the ISS. However, BUMPER II does not provide uncertainty bounds or confidence intervals for its predictions. In this paper, we present possible approaches through which uncertainty bounds can be developed for the various damage prediction and ballistic limit equations encoded within the Shuttle and Station versions of BUMPER II.
Isothermal life prediction of composite lamina using a damage mechanics approach
NASA Technical Reports Server (NTRS)
Abuelfoutouh, Nader M.; Verrilli, Michael J.; Halford, Gary R.
1989-01-01
A method for predicting isothermal plastic fatigue life of a composite lamina is presented in which both fibers and matrix are isotropic materials. In general, the fatigue resistances of the matrix, fibers, and interfacial material must be known in order to predict composite fatigue life. Composite fatigue life is predicted using only the matrix fatigue resistance due to inelasticity micromechanisms. The effect of the fiber orientation on loading direction is accounted for while predicting composite life. The application is currently limited to isothermal cases where the internal thermal stresses that might arise from thermal strain mismatch between fibers and matrix are negligible. The theory is formulated to predict the fatigue life of a composite lamina under either load or strain control. It is applied currently to predict the life of tungsten-copper composite lamina at 260 C under tension-tension load control. The calculated life of the lamina is in good agreement with available composite low cycle fatigue data.
Hookah tobacco use and stressful life events in a sample of young non-daily cigarette smokers.
Brikmanis, Kristin; Doran, Neal
2017-01-01
Understanding factors that influence hookah use among young adults is important given its increasing popularity and health risks. The purpose of this study was to examine whether young adult non-daily cigarette smokers use hookah for stress regulation. We hypothesized that greater perceived stress and greater stressful life events would predict probability and frequency of recent hookah use. Participants (n=598, 50.7% male) were non-daily smokers aged 18-24years (M=20.5, SD=1.8), who completed a baseline assessment online or via mobile phone as part of a longitudinal study. Participants had been non-daily smokers for at least six months but had never been daily smokers. Thirty-one percent of participants reported using hookah over the past 14days. Full-time students were more likely to have used hookah recently. More stressful life events and more frequent alcohol use predicted likelihood and frequency of hookah use (ps<0.05). Perceived stress was not associated with hookah use. Findings suggest that hookah tobacco use is related to frequency of stressful life events but not perceived stress among non-daily cigarette smokers. Tobacco prevention and intervention programs should address hookah use and should include adaptive strategies for coping with stressful events. Copyright © 2016 Elsevier Ltd. All rights reserved.
Fatigue criterion to system design, life and reliability
NASA Technical Reports Server (NTRS)
Zaretsky, E. V.
1985-01-01
A generalized methodology to structural life prediction, design, and reliability based upon a fatigue criterion is advanced. The life prediction methodology is based in part on work of W. Weibull and G. Lundberg and A. Palmgren. The approach incorporates the computed life of elemental stress volumes of a complex machine element to predict system life. The results of coupon fatigue testing can be incorporated into the analysis allowing for life prediction and component or structural renewal rates with reasonable statistical certainty.
Carlson, Linda E; Tamagawa, Rie; Stephen, Joanne; Doll, Richard; Faris, Peter; Dirkse, Dale; Speca, Michael
2014-11-01
Mindfulness-based cancer recovery (MBCR) and supportive-expressive therapy (SET) are well-validated psycho-oncological interventions, and we have previously reported health benefits of both programs. However, little is known about patients' characteristics or program preferences that may influence outcomes. Therefore, this study examined moderators of the effects of MBCR and SET on psychological well-being among breast cancer survivors. A multi-site randomized controlled trial was conducted between 2007 and 2012 in two Canadian cities (Calgary and Vancouver). A total of 271 distressed stage I-III breast cancer survivors were randomized into MBCR, SET or a 1-day stress management seminar (SMS). Baseline measures of moderator variables included program preference, personality traits, emotional suppression, and repressive coping. Outcome measures of mood, stress symptoms, quality of life, spiritual well-being, post-traumatic growth, social support, and salivary cortisol were measured pre- and post intervention. Hierarchical regression analyses were used to assess moderator effects on outcomes. The most preferred program was MBCR (55%). Those who were randomized to their preference improved more over time on quality of life and spiritual well-being post-intervention regardless of the actual intervention type received. Women with greater psychological morbidity at baseline showed greater improvement in stress symptoms and quality of life if they received their preferred versus nonpreferred program. Patients' program preference and baseline psychological functioning, rather than personality, were predictive of program benefits. These results suggest incorporating program preference can maximize the efficacy of integrative oncology interventions, and emphasize the methodological importance of assessing and accommodating for preferences when conducting mind-body clinical trials. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Reliability Practice at NASA Goddard Space Flight Center
NASA Technical Reports Server (NTRS)
Pruessner, Paula S.; Li, Ming
2008-01-01
This paper describes in brief the Reliability and Maintainability (R&M) Programs performed directly by the reliability branch at Goddard Space Flight Center (GSFC). The mission assurance requirements flow down is explained. GSFC practices for PRA, reliability prediction/fault tree analysis/reliability block diagram, FMEA, part stress and derating analysis, worst case analysis, trend analysis, limit life items are presented. Lessons learned are summarized and recommendations on improvement are identified.
Defense Acquisitions: Assessments of Selected Weapon Programs
2014-03-01
Frequency (UHF) Follow-On ( UFO ) satellite system currently in operation and provide interoperability with legacy terminals. MUOS consists of a...failures of two UFO satellites and predicted end-of-life of on-orbit UFO satellites, one of which was taken off-line in November 2012. A...needed because most on-orbit UFO satellites are past their design lives. Two of these unexpectedly failed—one in June 2005 and another in
CARES/LIFE Software Commercialization
NASA Technical Reports Server (NTRS)
1995-01-01
The NASA Lewis Research Center has entered into a letter agreement with BIOSYM Technologies Inc. (now merged with Molecular Simulations Inc. (MSI)). Under this agreement, NASA will provide a developmental copy of the CARES/LIFE computer program to BIOSYM for evaluation. This computer code predicts the time-dependent reliability of a thermomechanically loaded component. BIOSYM will become familiar with CARES/LIFE, provide results of computations useful in validating the code, evaluate it for potential commercialization, and submit suggestions for improvements or extensions to the code or its documentation. If BIOSYM/Molecular Simulations reaches a favorable evaluation of CARES/LIFE, NASA will enter into negotiations for a cooperative agreement with BIOSYM/Molecular Simulations to further develop the code--adding features such as a user-friendly interface and other improvements. This agreement would give BIOSYM intellectual property rights in the modified codes, which they could protect and then commercialize. NASA would provide BIOSYM with the NASA-developed source codes and would agree to cooperate with BIOSYM in further developing the code. In return, NASA would receive certain use rights in the modified CARES/LIFE program. Presently BIOSYM Technologies Inc. has been involved with integration issues concerning its merger with Molecular Simulations Inc., since both companies used to compete in the computational chemistry market, and to some degree, in the materials market. Consequently, evaluation of the CARES/LIFE software is on hold for a month or two while the merger is finalized. Their interest in CARES continues, however, and they expect to get back to the evaluation by early November 1995.
Accelerated testing of space mechanisms
NASA Technical Reports Server (NTRS)
Murray, S. Frank; Heshmat, Hooshang
1995-01-01
This report contains a review of various existing life prediction techniques used for a wide range of space mechanisms. Life prediction techniques utilized in other non-space fields such as turbine engine design are also reviewed for applicability to many space mechanism issues. The development of new concepts on how various tribological processes are involved in the life of the complex mechanisms used for space applications are examined. A 'roadmap' for the complete implementation of a tribological prediction approach for complex mechanical systems including standard procedures for test planning, analytical models for life prediction and experimental verification of the life prediction and accelerated testing techniques are discussed. A plan is presented to demonstrate a method for predicting the life and/or performance of a selected space mechanism mechanical component.
A new biodegradation prediction model specific to petroleum hydrocarbons.
Howard, Philip; Meylan, William; Aronson, Dallas; Stiteler, William; Tunkel, Jay; Comber, Michael; Parkerton, Thomas F
2005-08-01
A new predictive model for determining quantitative primary biodegradation half-lives of individual petroleum hydrocarbons has been developed. This model uses a fragment-based approach similar to that of several other biodegradation models, such as those within the Biodegradation Probability Program (BIOWIN) estimation program. In the present study, a half-life in days is estimated using multiple linear regression against counts of 31 distinct molecular fragments. The model was developed using a data set consisting of 175 compounds with environmentally relevant experimental data that was divided into training and validation sets. The original fragments from the Ministry of International Trade and Industry BIOWIN model were used initially as structural descriptors and additional fragments were then added to better describe the ring systems found in petroleum hydrocarbons and to adjust for nonlinearity within the experimental data. The training and validation sets had r2 values of 0.91 and 0.81, respectively.
Nuin, Maider; Alfaro, Begoña; Cruz, Ziortza; Argarate, Nerea; George, Susie; Le Marc, Yvan; Olley, June; Pin, Carmen
2008-10-31
Kinetic models were developed to predict the microbial spoilage and the sensory quality of fresh fish and to evaluate the efficiency of a commercial time-temperature integrator (TTI) label, Fresh Check(R), to monitor shelf life. Farmed turbot (Psetta maxima) samples were packaged in PVC film and stored at 0, 5, 10 and 15 degrees C. Microbial growth and sensory attributes were monitored at regular time intervals. The response of the Fresh Check device was measured at the same temperatures during the storage period. The sensory perception was quantified according to a global sensory indicator obtained by principal component analysis as well as to the Quality Index Method, QIM, as described by Rahman and Olley [Rahman, H.A., Olley, J., 1984. Assessment of sensory techniques for quality assessment of Australian fish. CSIRO Tasmanian Regional Laboratory. Occasional paper n. 8. Available from the Australian Maritime College library. Newnham. Tasmania]. Both methods were found equally valid to monitor the loss of sensory quality. The maximum specific growth rate of spoilage bacteria, the rate of change of the sensory indicators and the rate of change of the colour measurements of the TTI label were modelled as a function of temperature. The temperature had a similar effect on the bacteria, sensory and Fresh Check kinetics. At the time of sensory rejection, the bacterial load was ca. 10(5)-10(6) cfu/g. The end of shelf life indicated by the Fresh Check label was close to the sensory rejection time. The performance of the models was validated under fluctuating temperature conditions by comparing the predicted and measured values for all microbial, sensory and TTI responses. The models have been implemented in a Visual Basic add-in for Excel called "Fish Shelf Life Prediction (FSLP)". This program predicts sensory acceptability and growth of spoilage bacteria in fish and the response of the TTI at constant and fluctuating temperature conditions. The program is freely available at http://www.azti.es/muestracontenido.asp?idcontenido=980&content=15&nodo1=30&nodo2=0.
Results of prevention programs with adolescents.
Perry, C L
1987-09-01
Programs for preventing smoking and alcohol and drug abuse have radically changed in the past decade. Instead of being regarded as a health or discipline problem that involves only a few deviant adolescents, drug use has begun to be viewed as social behavior that is functional for adolescents, not capricious, and is normative for that population. The most successful prevention programs have sought to delay the onset of tobacco use. Based on theoretical and etiological research, these programs target factors that have repeatedly been predictive of adolescent smoking, alcohol and drug use. The programs teach adolescents (1) why people their age smoke tobacco or use alcohol and drugs; (2) how these meanings get established by peers, older role models and advertising; (3) how to resist these influences to smoke or to use alcohol and drugs; and (4) life skills and competencies to counterbalance the functions that drug use serves. Because of the association with the onset of smoking and the onset of using other drugs, these strategies are being studied for alcohol use and other drugs. In addition, elected peer leaders are trained to conduct these activities with their classmates and act as new role models for non-use. Evaluations of these approaches are optimistic. Studies in northern California and Minnesota reveal 50-70% reductions in the onset of smoking. Botvin's 'Life Skills Training' program demonstrates success in delaying heavy alcohol and marijuana use.
NASA's Evolutionary Xenon Thruster (NEXT) Long-Duration Test as of 736 kg of Propellant Throughput
NASA Technical Reports Server (NTRS)
Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.
2012-01-01
The NASA s Evolutionary Xenon Thruster (NEXT) program is developing the next-generation solar-electric ion propulsion system with significant enhancements beyond the state-of-the-art NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) ion propulsion system to provide future NASA science missions with enhanced mission capabilities. A Long-Duration Test (LDT) was initiated in June 2005 to validate the thruster service life modeling and to qualify the thruster propellant throughput capability. The thruster has set electric propulsion records for the longest operating duration, highest propellant throughput, and most total impulse demonstrated. At the time of this publication, the NEXT LDT has surpassed 42,100 h of operation, processed more than 736 kg of xenon propellant, and demonstrated greater than 28.1 MN s total impulse. Thruster performance has been steady with negligible degradation. The NEXT thruster design has mitigated several lifetime limiting mechanisms encountered in the NSTAR design, including the NSTAR first failure mode, thereby drastically improving thruster capabilities. Component erosion rates and the progression of the predicted life-limiting erosion mechanism for the thruster compare favorably to pretest predictions based upon semi-empirical ion thruster models used in the thruster service life assessment. Service life model validation has been accomplished by the NEXT LDT. Assuming full-power operation until test article failure, the models and extrapolated erosion data predict penetration of the accelerator grid grooves after more than 45,000 hours of operation while processing over 800 kg of xenon propellant. Thruster failure due to degradation of the accelerator grid structural integrity is expected after groove penetration.
NASA's Evolutionary Xenon Thruster (NEXT) Long-Duration Test as of 736 kg of Propellant Throughput
NASA Technical Reports Server (NTRS)
Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.
2012-01-01
The NASA s Evolutionary Xenon Thruster (NEXT) program is developing the next-generation solar-electric ion propulsion system with significant enhancements beyond the state-of-the-art NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) ion propulsion system to provide future NASA science missions with enhanced mission capabilities. A Long-Duration Test (LDT) was initiated in June 2005 to validate the thruster service life modeling and to qualify the thruster propellant throughput capability. The thruster has set electric propulsion records for the longest operating duration, highest propellant throughput, and most total impulse demonstrated. At the time of this publication, the NEXT LDT has surpassed 42,100 h of operation, processed more than 736 kg of xenon propellant, and demonstrated greater than 28.1 MN s total impulse. Thruster performance has been steady with negligible degradation. The NEXT thruster design has mitigated several lifetime limiting mechanisms encountered in the NSTAR design, including the NSTAR first failure mode, thereby drastically improving thruster capabilities. Component erosion rates and the progression of the predicted life-limiting erosion mechanism for the thruster compare favorably to pretest predictions based upon semi-empirical ion thruster models used in the thruster service life assessment. Service life model validation has been accomplished by the NEXT LDT. Assuming full-power operation until test article failure, the models and extrapolated erosion data predict penetration of the accelerator grid grooves after more than 45,000 hours of operation while processing over 800 kg of xenon propellant. Thruster failure due to degradation of the accelerator grid structural integrity is expected after
Sullivan, Michael C; Yeo, Heather; Roman, Sanziana A; Bell, Richard H; Sosa, Julie A
2013-03-01
To determine how marital status and having children impact US general surgical residents' attitudes toward training and personal life. There is a paucity of research describing how family and children affect the experience of general surgery residents. Cross-sectional survey involving all US categorical general surgery residents. Responses were evaluated by resident/program characteristics. Statistical analysis included the χ test and hierarchical logistic regression modeling. A total of 4402 residents were included (82.4% response rate) and categorized as married, single, or other (separated/divorced/widowed). Men were more likely to be married (57.8% vs 37.9%, P < 0.001) and have children (31.5% vs 12.0%, P < 0.001). Married residents were most likely to look forward to work (P < 0.001), and report happiness at work (P < 0.001) and a good program fit (P < 0.001). "Other" residents most frequently felt that work hours caused strain on family life (P < 0.001). Residents with children more frequently looked forward to work (P = 0.001), were happy at work (P = 0.001), and reported a good program fit (P = 0.034), but had strain on family life (P < 0.001), and worried about future finances (P = 0.005). On hierarchical logistic regression modeling, having children was predictive of a resident looking forward to work [odds ratio (OR): 1.22, P = 0.035], yet feeling that work caused family strain (OR: 1.66, P < 0.001); being single was associated with less strain (OR: 0.72, P < 0.001). The female gender was negatively associated with looking forward to work (OR: 0.81, P = 0.007). Residents who were married or parents reported greater satisfaction and work-life conflict. The complex effects of family on surgical residents should inform programs to target support mechanisms for their trainees.
Computational structural mechanics for engine structures
NASA Technical Reports Server (NTRS)
Chamis, C. C.
1989-01-01
The computational structural mechanics (CSM) program at Lewis encompasses: (1) fundamental aspects for formulating and solving structural mechanics problems, and (2) development of integrated software systems to computationally simulate the performance/durability/life of engine structures. It is structured to mainly supplement, complement, and whenever possible replace, costly experimental efforts which are unavoidable during engineering research and development programs. Specific objectives include: investigate unique advantages of parallel and multiprocesses for: reformulating/solving structural mechanics and formulating/solving multidisciplinary mechanics and develop integrated structural system computational simulators for: predicting structural performances, evaluating newly developed methods, and for identifying and prioritizing improved/missing methods needed. Herein the CSM program is summarized with emphasis on the Engine Structures Computational Simulator (ESCS). Typical results obtained using ESCS are described to illustrate its versatility.
Development of a prototype automatic controller for liquid cooling garment inlet temperature
NASA Technical Reports Server (NTRS)
Weaver, C. S.; Webbon, B. W.; Montgomery, L. D.
1982-01-01
The development of a computer control of a liquid cooled garment (LCG) inlet temperature is descirbed. An adaptive model of the LCG is used to predict the heat-removal rates for various inlet temperatures. An experimental system that contains a microcomputer was constructed. The LCG inlet and outlet temperatures and the heat exchanger outlet temperature form the inputs to the computer. The adaptive model prediction method of control is successful during tests where the inlet temperature is automatically chosen by the computer. It is concluded that the program can be implemented in a microprocessor of a size that is practical for a life support back-pack.
Probabilistic Analysis of Aircraft Gas Turbine Disk Life and Reliability
NASA Technical Reports Server (NTRS)
Melis, Matthew E.; Zaretsky, Erwin V.; August, Richard
1999-01-01
Two series of low cycle fatigue (LCF) test data for two groups of different aircraft gas turbine engine compressor disk geometries were reanalyzed and compared using Weibull statistics. Both groups of disks were manufactured from titanium (Ti-6Al-4V) alloy. A NASA Glenn Research Center developed probabilistic computer code Probable Cause was used to predict disk life and reliability. A material-life factor A was determined for titanium (Ti-6Al-4V) alloy based upon fatigue disk data and successfully applied to predict the life of the disks as a function of speed. A comparison was made with the currently used life prediction method based upon crack growth rate. Applying an endurance limit to the computer code did not significantly affect the predicted lives under engine operating conditions. Failure location prediction correlates with those experimentally observed in the LCF tests. A reasonable correlation was obtained between the predicted disk lives using the Probable Cause code and a modified crack growth method for life prediction. Both methods slightly overpredict life for one disk group and significantly under predict it for the other.
Bosma, Anouk Q; Kunst, Maarten J J; Dirkzwager, Anja J E; Nieuwbeerta, Paul
2017-06-01
The current study had three aims. First, it measured treatment readiness among offenders who entered the Prevention of Recidivism program. This is a prison-based rehabilitation program in the Netherlands that aims to lower re-offending rates among offenders with a prison sentence of at least for months and that is carried out during the final months of incarceration. Second, the study evaluated whether treatment readiness was associated with treatment participation. Third, the study examined whether treatment readiness measured with a validated instrument predicted treatment participation above and beyond a clinical assessment of treatment readiness, currently used as a criterion to include offenders in rehabilitation programs. To address these aims, data were used from the fourth wave of a research project studying the effects of imprisonment on the life of detainees in the Netherlands. Results indicated that treatment readiness as measured with a validated instrument was a significant predictor of treatment participation. Also, the current study showed that treatment readiness measured with a validated instrument improved the prediction of treatment participation above and beyond a clinical assessment of treatment readiness. Outcomes were discussed in light of study limitations and implications.
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.
Can Thrifty Gene(s) or Predictive Fetal Programming for Thriftiness Lead to Obesity?
Baig, Ulfat; Belsare, Prajakta; Watve, Milind; Jog, Maithili
2011-01-01
Obesity and related disorders are thought to have their roots in metabolic “thriftiness” that evolved to combat periodic starvation. The association of low birth weight with obesity in later life caused a shift in the concept from thrifty gene to thrifty phenotype or anticipatory fetal programming. The assumption of thriftiness is implicit in obesity research. We examine here, with the help of a mathematical model, the conditions for evolution of thrifty genes or fetal programming for thriftiness. The model suggests that a thrifty gene cannot exist in a stable polymorphic state in a population. The conditions for evolution of thrifty fetal programming are restricted if the correlation between intrauterine and lifetime conditions is poor. Such a correlation is not observed in natural courses of famine. If there is fetal programming for thriftiness, it could have evolved in anticipation of social factors affecting nutrition that can result in a positive correlation. PMID:21773010
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.
Turbine blade tip durability analysis
NASA Technical Reports Server (NTRS)
Mcknight, R. L.; Laflen, J. H.; Spamer, G. T.
1981-01-01
An air-cooled turbine blade from an aircraft gas turbine engine chosen for its history of cracking was subjected to advanced analytical and life-prediction techniques. The utility of advanced structural analysis techniques and advanced life-prediction techniques in the life assessment of hot section components are verified. Three dimensional heat transfer and stress analyses were applied to the turbine blade mission cycle and the results were input into advanced life-prediction theories. Shortcut analytical techniques were developed. The proposed life-prediction theories are evaluated.
Health-related quality-of-life in low-income, uninsured men with prostate cancer.
Krupski, Tracey L; Fink, Arlene; Kwan, Lorna; Maliski, Sally; Connor, Sarah E; Clerkin, Barbara; Litwin, Mark S
2005-05-01
The objective was to describe health-related quality-of-life (HRQOL) in low-income men with prostate cancer. Subjects were drawn from a statewide public assistance prostate cancer program. Telephone and mail surveys included the RAND 12-item Health Survey and UCLA Prostate Cancer Index Short Form and were compared with normative age-matched men without cancer from the general population reported on in the literature. Of 286 eligible men, 233 (81%) agreed to participate and completed the necessary items. The sample consisted of 51% Hispanics, 23% non-Hispanic whites, and 17% African Americans. The low-income men had worse scores in every domain of prostate-specific and general HRQOL than had the age-matched general population controls. The degree of disparity indicated substantial clinical differences in almost every domain of physical and emotional functioning between the sample group and the control group. Linear regression modeling determined that among the low-income men, Hispanic race, and income level were predictive of worse physical functioning, whereas only comorbidities predicted mental health. Low-income patients with prostate cancer appear to have quality-of-life profiles that are meaningfully worse than age-matched men from the general population without cancer reported on in the literature.
Results of inphase axial-torsional fatigue experiments on 304 stainless steel
NASA Technical Reports Server (NTRS)
Bonacuse, Peter J.; Kalluri, Sreeramesh
1989-01-01
A series of axial-torsional, inphase, strain-controlled, low-cycle fatigue tests were performed at room temperature on tubular specimens of 304 stainless steel. The program was conducted in cooperation with the task group on multiaxial fatigue research of ASTM committee E-09. The objective was to quantify the variability in multiaxial test results among several laboratories. Only included is data which was generated at the NASA Lewis Research Center's High Temperature Fatigue and Structures Laboratory. The experimental equipment and procedures used are described. The tubular specimens were polished on the outer surface to aid in the use of a cellulose film surface replication technique for crack detection. However, cracking initiated predominantly on the internal surface for all specimens. Honing of the bore of the tubular specimens lessened but did not entirely eliminate this problem. The observed fatigue lives are compared with lives calculated from three multiaxial life models. Constants for the life prediction models were obtained from uniaxial and torsional tests performed on the same heat of material. The observed fatigue lives agreed with calculated lives to within a factor of two for all but one of the life prediction models.
Xiao, Huimin; Kwong, Enid; Pang, Samantha; Mok, Esther
2013-01-01
Empirical data suggest that life review is an effective psychospiritual intervention. However, it has not been applied to Chinese patients with advanced cancer, and its effects on this population remain unknown. The aim of the study was to determine the effect of a life review program on quality of life among Chinese patients with advanced cancer. In this prospective randomized controlled trial, a total of 80 patients were randomly assigned to the life review program group and the control group. The 3-weekly life review program included reviewing a life and formulating a life review booklet. Outcome data were assessed by a collector who was blinded to group assignment before and immediately after the program and at a 3-week follow-up. Significantly better scores in overall quality of life, support, negative emotions, sense of alienation, existential distress, and value of life were found in the life review group immediately after the program and at the 3-week follow-up. This study provides additional data on the potential role of a life review in improving quality of life, particularly psychospiritual well being; it also indicates that the life review program could enable Chinese patients with advanced cancer to express their views on life and death. The life review program offers advanced cancer patients an opportunity to integrate their whole life experiences and discuss end-of-life issues, which lays the ground for further active intervention in their psychospiritual distress. The program could be integrated into daily home care to enhance the psychospiritual well-being of Chinese patients with advanced cancer.
Program For Evaluation Of Reliability Of Ceramic Parts
NASA Technical Reports Server (NTRS)
Nemeth, N.; Janosik, L. A.; Gyekenyesi, J. P.; Powers, Lynn M.
1996-01-01
CARES/LIFE predicts probability of failure of monolithic ceramic component as function of service time. Assesses risk that component fractures prematurely as result of subcritical crack growth (SCG). Effect of proof testing of components prior to service also considered. Coupled to such commercially available finite-element programs as ANSYS, ABAQUS, MARC, MSC/NASTRAN, and COSMOS/M. Also retains all capabilities of previous CARES code, which includes estimation of fast-fracture component reliability and Weibull parameters from inert strength (without SCG contributing to failure) specimen data. Estimates parameters that characterize SCG from specimen data as well. Written in ANSI FORTRAN 77 to be machine-independent. Program runs on any computer in which sufficient addressable memory (at least 8MB) and FORTRAN 77 compiler available. For IBM-compatible personal computer with minimum 640K memory, limited program available (CARES/PC, COSMIC number LEW-15248).
Ceramic Technology for Advanced Heat Engines Project
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1989-08-01
The Ceramic Technology for Advanced Heat Engines Project was developed by the Department of Energy's Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Advanced Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional researchmore » is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially.« less
NASA Astrophysics Data System (ADS)
Szelepcsényi, Zoltán; Breuer, Hajnalka; Sümegi, Pál
2014-05-01
Nowadays more and more environmental lobbyists believe that climate change must be demonstrated in a new form. The estimated temperature increase can be realized more easily, if the emphasis is on ecological effects of the predicted temperature. For this reason a bioclimatic classification method was used to analyse the projected changes for the Carpathian Basin region. We applied the Holdridge life zone system, which is relatively simple, so our results can be used to inform the population. Holdridge developed a geometric model for climate classification which declares the relationship between classes (life zones) and climate indices (mean annual biotemperature, average total annual precipitation, potential evapotranspiration ratio). The necessary data for this study was derived from regional climate model (RCM) experiments of the ENSEMBLES project using the SRES A1B emission scenario. The temperature and precipitation data series were bias corrected for the selected RCM simulations. The target area of our investigations is the Carpathian Basin region. Life zones maps were created using the selected RCM simulations and their ensemble mean for the periods: 1961-1990 (T1), 2021-2050 (T2), 2061-2090 (T3). The spatial distribution of life zones and their temporal changes were investigated. According to our results the spatial pattern of life zones changes significantly from T1 to T3. It is possible that some types of life zones (e.g. boreal rain forest) will disappear; and some types (e.g. warm temperate thorn steppe) will appear in the target area. We determined those RCM simulations which predicted the maximum and minimum changes of the spatial pattern of life zones. Maps of T1 were compared to maps of T3 using Cohen's Kappa coefficient. Furthermore, relative extents, vertical distribution patterns and mean centres of life zones have been analysed. These parameters were defined for each decade and also for T1, T2 and T3. The temporal changes of the decadal values were analysed with Mann-Kendall trend test. Overall, our results predict that the mean centres of life zones will shift towards north in most cases. This research was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP-4.2.4.A/ 2-11/1-2012-0001 'National Excellence Program'.
Fatigue crack growth and life prediction under mixed-mode loading
NASA Astrophysics Data System (ADS)
Sajith, S.; Murthy, K. S. R. K.; Robi, P. S.
2018-04-01
Fatigue crack growth life as a function of crack length is essential for the prevention of catastrophic failures from damage tolerance perspective. In damage tolerance design approach, principles of fracture mechanics are usually applied to predict the fatigue life of structural components. Numerical prediction of crack growth versus number of cycles is essential in damage tolerance design. For cracks under mixed mode I/II loading, modified Paris law (d/a d N =C (ΔKe q ) m ) along with different equivalent stress intensity factor (ΔKeq) model is used for fatigue crack growth rate prediction. There are a large number of ΔKeq models available for the mixed mode I/II loading, the selection of proper ΔKeq model has significant impact on fatigue life prediction. In the present investigation, the performance of ΔKeq models in fatigue life prediction is compared with respect to the experimental findings as there are no guidelines/suggestions available on the selection of these models for accurate and/or conservative predictions of fatigue life. Within the limitations of availability of experimental data and currently available numerical simulation techniques, the results of present study attempt to outline models that would provide accurate and conservative life predictions. Such a study aid the numerical analysts or engineers in the proper selection of the model for numerical simulation of the fatigue life. Moreover, the present investigation also suggests a procedure to enhance the accuracy of life prediction using Paris law.
Modeling and Prediction of Corrosion-Fatigue Failures in AF1410 Steel Test Specimens
2009-01-12
PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Structures Division, Code 4.3.3 University of Dayton Research Bldg. 2187 Room 2340A Institute Naval...AND ADDRESS(ES) Office of Naval Research One Liberty Center 875 North Randolph St., Suite 1425 Arlington, VA 22203-1995 11. SPONSOR/MONITOR’S...costs. To address these issues, NAVAIR has initiated a multiyear research program to investigate and quantify the fatigue life reduction due to
The physics of cellular synthesis, growth and division
NASA Technical Reports Server (NTRS)
Pollard, E. C.
1974-01-01
Three areas of research in NASA'S University Program are described. Primitive terrestrial living cells were studied as a guide to the kind of cells to look for in extraterrestrial life. Experiments in zero gravity conditions are described with emphasis upon effects on small organisms. The effects of ionizing radiation on cells are studied so that it will be possible to predict dosages which can be tolerated by humans with no permanent damage.
2009-03-01
regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington...Good Morning, featuring live and recorded segments on life, culture, art, and nutrition ; Nuts and Sugar, a children’s program with puppets, skits...resistance, the failure of Israel to achieve particular goals, and the prediction that Israel would likely reduce its goals. There is no
Combustor liner durability analysis
NASA Technical Reports Server (NTRS)
Moreno, V.
1981-01-01
An 18 month combustor liner durability analysis program was conducted to evaluate the use of advanced three dimensional transient heat transfer and nonlinear stress-strain analyses for modeling the cyclic thermomechanical response of a simulated combustor liner specimen. Cyclic life prediction technology for creep/fatigue interaction is evaluated for a variety of state-of-the-art tools for crack initiation and propagation. The sensitivity of the initiation models to a change in the operating conditions is also assessed.
Technical accomplishments of the NASA Lewis Research Center, 1989
NASA Technical Reports Server (NTRS)
1990-01-01
Topics addressed include: high-temperature composite materials; structural mechanics; fatigue life prediction for composite materials; internal computational fluid mechanics; instrumentation and controls; electronics; stirling engines; aeropropulsion and space propulsion programs, including a study of slush hydrogen; space power for use in the space station, in the Mars rover, and other applications; thermal management; plasma and radiation; cryogenic fluid management in space; microgravity physics; combustion in reduced gravity; test facilities and resources.
Experimental Resource Allocation for Statistical Simulation of Fretting Fatigue Problem (Preprint)
2012-08-01
Metals Branch Structural Materials Division Harry R. Millwater , Carolina Dubinsky, and Gulshan Singh University of Texas at San Antonio...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR(S) Patrick Golden (AFRL/RXCM) Harry R. Millwater , Carolina Dubinsky, and Gulshan...Safety. 1996;54(2-3):133-144 [5] Golden, PJ, Millwater HR and Yang X. Probabilistic Fretting Fatigue Life Prediction of Ti-6Al-4V. International Journal
Total Ownership Cost a Decade Into the 21st Century
2012-09-30
lecturer and academic associate for Program Management Curricula, Graduate School of Business and Public Policy, Naval Postgraduate School. While on...F cost $15,346 per flight hour of operation—40% higher than the $10,979 predicted in 1999. Institute for Defense Analyses Study: The Major Causes of...this working paper perceive as a shortsighted goal of obtaining funds for development and procurement to the more complete perspective of total life
Discovering a vaccine against neosporosis using computers: is it feasible?
Goodswen, Stephen J; Kennedy, Paul J; Ellis, John T
2014-08-01
A vaccine is urgently needed to prevent cattle neosporosis. This infectious disease is caused by the parasite Neospora caninum, a complex biological system with multifaceted life cycles. An in silico vaccine discovery approach attempts to transform digital abstractions of this system into adequate knowledge to predict candidates. Researchers need current information to implement such an approach, such as understanding evasion mechanisms of the immune system, type of immune response to elicit, availability of data and prediction programs, and statistical models to analyze predictions. Taken together, an in silico approach involves assembly of an intricate jigsaw of interdisciplinary and interdependent knowledge. In this review, we focus on the approach influencing vaccine development against Neospora caninum, which can be generalized to other pathogenic apicomplexans. Copyright © 2014 Elsevier Ltd. All rights reserved.
Engine Structures Modeling Software System (ESMOSS)
NASA Technical Reports Server (NTRS)
1991-01-01
Engine Structures Modeling Software System (ESMOSS) is the development of a specialized software system for the construction of geometric descriptive and discrete analytical models of engine parts, components, and substructures which can be transferred to finite element analysis programs such as NASTRAN. The NASA Lewis Engine Structures Program is concerned with the development of technology for the rational structural design and analysis of advanced gas turbine engines with emphasis on advanced structural analysis, structural dynamics, structural aspects of aeroelasticity, and life prediction. Fundamental and common to all of these developments is the need for geometric and analytical model descriptions at various engine assembly levels which are generated using ESMOSS.
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.
Rolling Bearing Life Prediction, Theory, and Application
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin V.
2016-01-01
A tutorial is presented outlining the evolution, theory, and application of rolling-element bearing life prediction from that of A. Palmgren, 1924; W. Weibull, 1939; G. Lundberg and A. Palmgren, 1947 and 1952; E. Ioannides and T. Harris, 1985; and E. Zaretsky, 1987. Comparisons are made between these life models. The Ioannides-Harris model without a fatigue limit is identical to the Lundberg-Palmgren model. The Weibull model is similar to that of Zaretsky if the exponents are chosen to be identical. Both the load-life and Hertz stress-life relations of Weibull, Lundberg and Palmgren, and Ioannides and Harris reflect a strong dependence on the Weibull slope. The Zaretsky model decouples the dependence of the critical shear stress-life relation from the Weibull slope. This results in a nominal variation of the Hertz stress-life exponent. For 9th- and 8th-power Hertz stress-life exponents for ball and roller bearings, respectively, the Lundberg-Palmgren model best predicts life. However, for 12th- and 10th-power relations reflected by modern bearing steels, the Zaretsky model based on the Weibull equation is superior. Under the range of stresses examined, the use of a fatigue limit would suggest that (for most operating conditions under which a rolling-element bearing will operate) the bearing will not fail from classical rolling-element fatigue. Realistically, this is not the case. The use of a fatigue limit will significantly overpredict life over a range of normal operating Hertz stresses. (The use of ISO 281:2007 with a fatigue limit in these calculations would result in a bearing life approaching infinity.) Since the predicted lives of rolling-element bearings are high, the problem can become one of undersizing a bearing for a particular application. Rules had been developed to distinguish and compare predicted lives with those actually obtained. Based upon field and test results of 51 ball and roller bearing sets, 98 percent of these bearing sets had acceptable life results using the Lundberg- Palmgren equations with life adjustment factors to predict bearing life. That is, they had lives equal to or greater than that predicted. The Lundberg-Palmgren model was used to predict the life of a commercial turboprop gearbox. The life prediction was compared with the field lives of 64 gearboxes. From these results, the roller bearing lives exhibited a load-life exponent of 5.2, which correlated with the Zaretsky model. The use of the ANSI/ABMA and ISO standards load-life exponent of 10/3 to predict roller bearing life is not reflective of modern roller bearings and will underpredict bearing lives.
Aging of Weapon Seals – An Update on Butyl O-ring Issues
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wilson, Mark H.
2011-07-13
During testing under the Enhanced Surveillance Campaign in 2001, preliminary data detected a previously unknown and potentially serious concern with recently procured butyl o-rings on several programs. All butyl o-rings molded from a proprietary formulation throughout the period circa 1999 through 2001 had less than a full cure. Engineering judgment was that under curing is detrimental and could possibly lead to sub-optimum performance or, in the worst case, premature seal failure. An aging study was undertaken to ensure that suspect o-rings installed in the stockpile will retain sufficient sealing force for a minimum ten-year service life. A new prediction modelmore » developed for this study indicates suspect o-rings do not need to be replaced before the ten-year service life. Long-term testing results are reported on a yearly basis to validate the prediction model. This report documents the aging results for the period September 2002 to January 2011.« less
Paul, Lisa A; Kehn, Andre; Gray, Matt J; Salapska-Gelleri, Joanna
2014-01-01
Undergraduate rape disclosure recipients' and nonrecipients' sociodemographic and life experience variables, attitudes towards rape, and responses to a hypothetical rape disclosure were compared to determine differences between them. One hundred ninety-two undergraduates at 3 universities participated in this online survey between November 2011 and April 2012. Participants reported on their rape myth acceptance (RMA) and personal direct and indirect (ie, disclosure receipt) experiences with sexual assault. Participants also responded to a hypothetical rape disclosure. Disclosure recipients were more likely to report a victimization history, and less confusion and perceived ineffectiveness in helping the hypothetical victim. RMA and nonrecipient status predicted perceived victim responsibility; these variables and childhood victimization predicted confusion about helping. RMA also predicted perceived ineffectiveness of one's helping behaviors. Victimization history and female gender predicted victim empathy. These findings can inform sexual assault-related programming for undergraduates through the provision of targeted assistance and corrective information.
Stirling engine - Approach for long-term durability assessment
NASA Technical Reports Server (NTRS)
Tong, Michael T.; Bartolotta, Paul A.; Halford, Gary R.; Freed, Alan D.
1992-01-01
The approach employed by NASA Lewis for the long-term durability assessment of the Stirling engine hot-section components is summarized. The approach consists of: preliminary structural assessment; development of a viscoplastic constitutive model to accurately determine material behavior under high-temperature thermomechanical loads; an experimental program to characterize material constants for the viscoplastic constitutive model; finite-element thermal analysis and structural analysis using a viscoplastic constitutive model to obtain stress/strain/temperature at the critical location of the hot-section components for life assessment; and development of a life prediction model applicable for long-term durability assessment at high temperatures. The approach should aid in the provision of long-term structural durability and reliability of Stirling engines.
Heckman, James J.; Kautz, Tim
2012-01-01
This paper summarizes recent evidence on what achievement tests measure; how achievement tests relate to other measures of “cognitive ability” like IQ and grades; the important skills that achievement tests miss or mismeasure, and how much these skills matter in life. Achievement tests miss, or perhaps more accurately, do not adequately capture, soft skills—personality traits, goals, motivations, and preferences that are valued in the labor market, in school, and in many other domains. The larger message of this paper is that soft skills predict success in life, that they causally produce that success, and that programs that enhance soft skills have an important place in an effective portfolio of public policies. PMID:23559694
DeHart, Dana D; Moran, Robert
2015-03-01
Life History Calendars and the Juvenile Victimization Questionnaire were used to collect data from 100 delinquent girls to (a) examine range and co-occurrence of different types of violence over the life span, (b) examine independent and cumulative trajectories of risk for varied types of victimization, and (c) examine the relationship of victimization to girls' offending. Risk trajectories demonstrate critical risk periods for different forms of violence exposure. Cox regression was used to examine the predictive value of different forms of violence exposure for the onset of delinquent and criminal behavior. Findings illuminate the need for programs addressing substance use and alternative coping mechanisms. © The Author(s) 2015.
α decay properties of 297Og within the two-potential approach
NASA Astrophysics Data System (ADS)
Deng, Jun-Gang; Cheng, Jun-Hao; Zheng, Bo; Li, Xiao-Hua
2017-12-01
The α decay half-life of the unknown nucleus 297Og is predicted within the two-potential approach, and α preformation probabilities of 64 odd-A nuclei in the region of proton numbers 82 < Z < 126 and neutron numbers 152 < N < 184, from 251Cf to 295Og, are extracted. In addition, based on the latest experimental data, a new set of parameters for α preformation probabilities considering the shell effect and proton-neutron interaction are obtained. The predicted α decay half-life of 297Og is 0.16 ms within a factor of 4.97. The predicted spin and parity of the ground states for 269Sg, 285Fl and 293Lv are 3/2+, 3/2+ and 5/2+, respectively. Supported by National Natural Science Foundation of China (11205083, 11505100), Construct Program of the Key Discipline in Hunan Province, the Research Foundation of Education Bureau of Hunan Province, China (15A159), the Natural Science Foundation of Hunan Province, China (2015JJ3103, 2015JJ2121), the Innovation Group of Nuclear and Particle Physics in USC, the Shandong Province Natural Science Foundation, China (ZR2015AQ007) and Hunan Provincial Innovation Foundation For Postgraduate (CX2017B536)
The home stroke rehabilitation and monitoring system trial: a randomized controlled trial.
Linder, Susan M; Rosenfeldt, Anson B; Reiss, Aimee; Buchanan, Sharon; Sahu, Komal; Bay, Curtis R; Wolf, Steven L; Alberts, Jay L
2013-01-01
Because many individuals poststroke lack access to the quality and intensity of rehabilitation to improve upper extremity motor function, a home-based robotic-assisted upper extremity rehabilitation device is being paired with an individualized home exercise program. The primary aim of this project is to determine the effectiveness of robotic-assisted home therapy compared with a home exercise program on upper extremity motor recovery and health-related quality of life for stroke survivors in rural and underserved locations. The secondary aim is to explore whether initial degree of motor function of the upper limb may be a factor in predicting the extent to which patients with stroke may be responsive to a home therapy approach. We hypothesize that the home exercise program intervention, when enhanced with robotic-assisted therapy, will result in significantly better outcomes in motor function and quality of life. A total of 96 participants within six-months of a single, unilateral ischemic, or hemorrhagic stroke will be recruited in this prospective, single-blind, multisite randomized clinical trial. The primary outcome is the change in upper extremity function using the Action Research Arm Test. Secondary outcomes include changes in: upper extremity function (Wolf Motor Function Test), upper extremity impairment (upper extremity portion of the Fugl-Meyer Test), self-reported quality of life (Stroke Impact Scale), and affect (Centers for Epidemiologic Studies Depression Scale). Similar or greater improvements in upper extremity function using the combined robotic home exercise program intervention compared with home exercise program alone will be interpreted as evidence that supports the introduction of in-home technology to augment the recovery of function poststroke. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.
A Growth Model for Academic Program Life Cycle (APLC): A Theoretical and Empirical Analysis
ERIC Educational Resources Information Center
Acquah, Edward H. K.
2010-01-01
Academic program life cycle concept states each program's life flows through several stages: introduction, growth, maturity, and decline. A mixed-influence diffusion growth model is fitted to enrolment data on academic programs to analyze the factors determining progress of academic programs through their life cycles. The regression analysis yield…
Aging and immortality: quasi-programmed senescence and its pharmacologic inhibition.
Blagosklonny, Mikhail V
2006-09-01
While ruling out programmed aging, evolutionary theory predicts a quasi-program for aging, a continuation of the developmental program that is not turned off, is constantly on, becoming hyper-functional and damaging, causing diseases of aging. Could it be switched off pharmacologically? This would require identification of a molecular target involved in cell senescence, organism aging and diseases of aging. Notably, cell senescence is associated with activation of the TOR (target of rapamycin) nutrient- and mitogen-sensing pathway, which promotes cell growth, even though cell cycle is blocked. Is TOR involved in organism aging? In fact, in yeast (where the cell is the organism), caloric restriction, rapamycin and mutations that inhibit TOR all slow down aging. In animals from worms to mammals caloric restrictions, life-extending agents, and numerous mutations that increase longevity all converge on the TOR pathway. And, in humans, cell hypertrophy, hyper-function and hyperplasia, typically associated with activation of TOR, contribute to diseases of aging. Theoretical and clinical considerations suggest that rapamycin may be effective against atherosclerosis, hypertension and hyper-coagulation (thus, preventing myocardial infarction and stroke), osteoporosis, cancer, autoimmune diseases and arthritis, obesity, diabetes, macula-degeneration, Alzheimer's and Parkinson's diseases. Finally, I discuss that extended life span will reveal new causes for aging (e.g., ROS, 'wear and tear', Hayflick limit, stem cell exhaustion) that play a limited role now, when quasi-programmed senescence kills us first.
Battersby, Malcolm; Harris, Melanie; Smith, David; Reed, Richard; Woodman, Richard
2015-11-01
To evaluate the Flinders Program in improving self-management in common chronic conditions. To examine properties of the Partners in Health scale (PIH). Participants were randomized to usual care or Flinders Program plus usual care. Self-management competency, quality of life, and other outcomes were measured at baseline, 6 months, and 12 months. Of 231 participants, 172 provided data at 6 months and 61 at 12 months. At 6 months, intention-to-treat outcomes favoured the intervention group for SF-12 physical health (p=0.043). Other pre-determined outcomes did not show significance. At 6 months intervention participants' problem severity scores reduced (p<0.001) and goal achievement scores increased (p<0.001). Only 55% of the intervention group received a Flinders Program, compromising study power. The PIH was associated with other measures at baseline and for change over time. In a pragmatic community trial, the Flinders Program improved quality of life at 6 months. Incomplete in-practice intervention delivery limited trial power. Studies are now needed on improving delivery. The PIH has potential as a generic risk screening tool and predictive measure of change in self-management and chronic condition outcomes over time. Better implementation including service integration is required for improved chronic disease management. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Spring, Samuel D.
2006-01-01
This report documents the results of an experimental program conducted on two advanced metallic alloy systems (Rene' 142 directionally solidified alloy (DS) and Rene' N6 single crystal alloy) and the characterization of two distinct internal state variable inelastic constitutive models. The long term objective of the study was to develop a computational life prediction methodology that can integrate the obtained material data. A specialized test matrix for characterizing advanced unified viscoplastic models was specified and conducted. This matrix included strain controlled tensile tests with intermittent relaxtion test with 2 hr hold times, constant stress creep tests, stepped creep tests, mixed creep and plasticity tests, cyclic temperature creep tests and tests in which temperature overloads were present to simulate actual operation conditions for validation of the models. The selected internal state variable models where shown to be capable of representing the material behavior exhibited by the experimental results; however the program ended prior to final validation of the models.
Experimental and theoretical investigation of fatigue life in reusable rocket thrust chambers
NASA Technical Reports Server (NTRS)
Hannum, N. P.; Kasper, H. J.; Pavli, A. J.
1976-01-01
During a test program to investigate low-cycle thermal fatigue, 13 rocket combustion chambers were fabricated and cyclically test fired to failure. Six oxygen-free, high-conductivity (OFHC) copper and seven Amzirc chambers were tested. The chamber liners were fabricated of copper or copper alloy and contained milled coolant channels. The chambers were completed by means of an electroformed nickel closeout. The oxidant/fuel ratio for the liquid oxygen and gaseous hydrogen propellants was 6.0. The failures in the OFHC copper chambers were not typical fatigue failures but are described as creep rupture enhanced by ratcheting. The coolant channels bulged toward the chamber centerline, resulting in progressive thinning of the wall during each cycle. The failures in the Amzirc alloy chambers were caused by low-cycle thermal fatigue. The lives were much shorter than were predicted by an analytical structural analysis computer program used in conjunction with fatigue life data from isothermal test specimens, due to the uneven distribution of Zr in the chamber material.
Creswell, Kasey G.; Chung, Tammy; Clark, Duncan B.; Martin, Christopher S.
2015-01-01
Adolescent solitary drinking may represent an informative divergence from normative behavior, with important implications for understanding risk for alcohol-use disorders later in life. Within a self-medication framework, we hypothesized that solitary alcohol use would be associated with drinking in response to negative affect and that such a pattern of drinking would predict alcohol problems in young adulthood. We tested these predictions in a longitudinal study in which we examined whether solitary drinking in adolescence (ages 12–18) predicted alcohol-use disorders in young adulthood (age 25) in 466 alcohol-using teens recruited from clinical programs and 243 alcohol-using teens recruited from the community. Findings showed that solitary drinking was associated with drinking in response to negative affect during adolescence and predicted alcohol problems in young adulthood. Results indicate that drinking alone is an important type of alcohol-use behavior that increases risk for the escalation of alcohol use and the development of alcohol problems. PMID:25977842
Creswell, Kasey G; Chung, Tammy; Clark, Duncan B; Martin, Christopher S
2014-09-01
Adolescent solitary drinking may represent an informative divergence from normative behavior, with important implications for understanding risk for alcohol-use disorders later in life. Within a self-medication framework, we hypothesized that solitary alcohol use would be associated with drinking in response to negative affect and that such a pattern of drinking would predict alcohol problems in young adulthood. We tested these predictions in a longitudinal study in which we examined whether solitary drinking in adolescence (ages 12-18) predicted alcohol-use disorders in young adulthood (age 25) in 466 alcohol-using teens recruited from clinical programs and 243 alcohol-using teens recruited from the community. Findings showed that solitary drinking was associated with drinking in response to negative affect during adolescence and predicted alcohol problems in young adulthood. Results indicate that drinking alone is an important type of alcohol-use behavior that increases risk for the escalation of alcohol use and the development of alcohol problems.
Remaining Useful Life Estimation in Prognosis: An Uncertainty Propagation Problem
NASA Technical Reports Server (NTRS)
Sankararaman, Shankar; Goebel, Kai
2013-01-01
The estimation of remaining useful life is significant in the context of prognostics and health monitoring, and the prediction of remaining useful life is essential for online operations and decision-making. However, it is challenging to accurately predict the remaining useful life in practical aerospace applications due to the presence of various uncertainties that affect prognostic calculations, and in turn, render the remaining useful life prediction uncertain. It is challenging to identify and characterize the various sources of uncertainty in prognosis, understand how each of these sources of uncertainty affect the uncertainty in the remaining useful life prediction, and thereby compute the overall uncertainty in the remaining useful life prediction. In order to achieve these goals, this paper proposes that the task of estimating the remaining useful life must be approached as an uncertainty propagation problem. In this context, uncertainty propagation methods which are available in the literature are reviewed, and their applicability to prognostics and health monitoring are discussed.
NASA Astrophysics Data System (ADS)
Mu, G. Y.; Mi, X. Z.; Wang, F.
2018-01-01
The high temperature low cycle fatigue tests of TC4 titanium alloy and TC11 titanium alloy are carried out under strain controlled. The relationships between cyclic stress-life and strain-life are analyzed. The high temperature low cycle fatigue life prediction model of two kinds of titanium alloys is established by using Manson-Coffin method. The relationship between failure inverse number and plastic strain range presents nonlinear in the double logarithmic coordinates. Manson-Coffin method assumes that they have linear relation. Therefore, there is bound to be a certain prediction error by using the Manson-Coffin method. In order to solve this problem, a new method based on exponential function is proposed. The results show that the fatigue life of the two kinds of titanium alloys can be predicted accurately and effectively by using these two methods. Prediction accuracy is within ±1.83 times scatter zone. The life prediction capability of new methods based on exponential function proves more effective and accurate than Manson-Coffin method for two kinds of titanium alloys. The new method based on exponential function can give better fatigue life prediction results with the smaller standard deviation and scatter zone than Manson-Coffin method. The life prediction results of two methods for TC4 titanium alloy prove better than TC11 titanium alloy.
Ferreira, João Pedro; Duarte, Kevin; Graves, Todd L; Zile, Michael R; Abraham, William T; Weaver, Fred A; Lindenfeld, JoAnn; Zannad, Faiez
2016-12-20
The Expedited Access for Premarket Approval and De Novo Medical Devices Intended for Unmet Medical Need for Life Threatening or Irreversibly Debilitating Diseases or Conditions document was issued as a guidance for industry and for the Food and Drug Administration. The Expedited Access Pathway was designed as a new program for medical devices that demonstrated the potential to address unmet medical needs for life threatening or irreversibly debilitating conditions. The Food and Drug Administration would consider assessments of a device's effect on intermediate endpoints that, when improving in a congruent fashion, are reasonably likely to predict clinical benefit. The purpose of this review is to provide evidence to support the use of 3 such intermediate endpoints: natriuretic peptides, such as N-terminal pro-B-type natriuretic peptide/B-type natriuretic peptide, the 6-min walk test distance, and health-related quality of life in heart failure. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Armand, Sasan C.; Liao, Mei-Hwa; Morris, Ronald W.
1990-01-01
The Space Station Freedom photovoltaic solar array blanket assembly is comprised of several layers of materials having dissimilar elastic, thermal, and mechanical properties. The operating temperature of the solar array, which ranges from -75 to +60 C, along with the material incompatibility of the blanket assembly components combine to cause an elastic-plastic stress in the weld points of the assembly. The weld points are secondary structures in nature, merely serving as electrical junctions for gathering the current. The thermal mechanical loading of the blanket assembly operating in low earth orbit continually changes throughout each 90 min orbit, which raises the possibility of fatigue induced failure. A series of structural analyses were performed in an attempt to predict the fatigue life of the solar cell in the Space Station Freedom photovoltaic array blanket. A nonlinear elastic-plastic MSC/NASTRAN analysis followed by a fatigue calculation indicated a fatigue life of 92,000 to 160,000 cycles for the solar cell weld tabs. Additional analyses predict a permanent buckling phenomenon in the copper interconnect after the first loading cycle. This should reduce or eliminate the pulling of the copper interconnect on the joint where it is welded to the silicon solar cell. It is concluded that the actual fatigue life of the solar array blanket assembly should be significantly higher than the calculated 92,000 cycles, and thus the program requirement of 87,500 cycles (orbits) will be met. Another important conclusion that can be drawn from the overall analysis is that, the strain results obtained from the MSC/NASTRAN nonlinear module are accurate to use for low-cycle fatigue analysis, since both thermal cycle testing of solar cells and analysis have shown higher fatigue life than the minimum program requirement of 87,500 cycles.
High temperature fatigue behavior of Haynes 188
NASA Technical Reports Server (NTRS)
Halford, Gary R.; Saltsman, James F.; Kalluri, Sreeramesh
1988-01-01
The high temperature, creep-fatigue behavior of Haynes 188 was investigated as an element in a broader thermomechanical fatigue life prediction model development program at the NASA-Lewis. The models are still in the development stage, but the data that were generated possess intrinsic value on their own. Results generated to date is reported. Data were generated to characterize isothermal low cycle fatigue resistance at temperatures of 316, 704, and 927 C with cyclic failure lives ranging from 10 to more than 20,000. These results follow trends that would be predicted from a knowledge of tensile properties, i.e., as the tensile ductility varies with temperature, so varies the cyclic inelastic straining capacity. Likewise, as the tensile strength decreases, so does the high cyclic fatigue resistance. A few two-minute hold-time cycles at peak compressive strain were included in tests at 760 C. These results were obtained in support of a redesign effort for the Orbital Maneuverable System engine. No detrimental effects on cyclic life were noted despite the added exposure time for creep and oxidation. Finally, a series of simulated thermal fatigue tests, referred to as bithermal fatigue tests, were conducted using 316 C as the minimum and 760 C as the maximum temperature. Only out-of-phase bithermal tests were conducted to date. These test results are intended for use as input to a more general thermomechanical fatigue life prediction model based on the concepts of the total strain version of Strainrange Partitioning.
Four-year prospective evaluation of the relationship between meaning in life and smoking status
2013-01-01
Background To date, all investigations on the relationship between smoking and perceived level of meaning in life have used cross-sectional designs. Therefore, the purpose of the present prospective study, conducted with a four-year time lag, was to test the predictive power of the life meaning construct concerning changes in smoking status. Methods The data of 4,294 respondents (40.3% male, Mage = 54.7 ± 16.5 yrs) from the Hungarian Epidemiological Panel Survey were analyzed using the Kruskal-Wallis and Mann–Whitney U-test and structural equation modeling (SEM) with a nominal outcome variable. Gender, age, and educational level were included in the study as covariates. Results On the bivariate level, results showed that both baseline and follow-up meaning in life scores were higher in stable non-smokers when compared to stable smokers. However, quitters and starters differed from stable non-smokers in their baseline but not in follow-up life meaning scores. The other relationships (stable smokers vs. quitters; stable smokers vs. starters, starters vs. quitters) were non-significant in both time points. According to the SEM-analysis, a higher sense of meaning in life measured at baseline and follow-up is associated with a lower likelihood (OR = 0.54, z = 2.80, p = 0.005; OR = 0.64, z = 2.88, p = 0.004, respectively) of being a stable smoker compared to being a stable non-smoker, confirming the expected relationship between smoking and decreased level of meaning in life. However, neither baseline nor follow-up life meaning scores predicted significantly quitting and uptake of smoking. Conclusions If future research from other cultures verifies the protective role of a higher level of meaning in life against smoking, then smoking prevention and cessation programs will also have to include such components that help individuals experience more meaning in their lives. PMID:23433067
Bluth, Karen; Gaylord, Susan A.; Campo, Rebecca A.; Mullarkey, Michael C.; Hobbs, Lorraine
2015-01-01
The aims of this mixed-method pilot study were to determine the feasibility, acceptability, and preliminary psychosocial outcomes of “Making Friends with Yourself: A Mindful Self-Compassion Program for Teens” (MFY), an adaptation of the adult Mindful Self-Compassion program. Thirty-four students age 14–17 enrolled in this waitlist controlled crossover study. Participants were randomized to either the waitlist or intervention group and administered online surveys at baseline, after the first cohort participated in the intervention, and after the waitlist crossovers participated in the intervention. Attendance and retention data were collected to determine feasibility, and audiorecordings of the 6-week class were analyzed to determine acceptability of the program. Findings indicated that MFY is a feasible and acceptable program for adolescents. Compared to the waitlist control, the intervention group had significantly greater self-compassion and life satisfaction and significantly lower depression than the waitlist control, with trends for greater mindfulness, greater social connectedness and lower anxiety. When waitlist crossovers results were combined with that of the first intervention group, findings indicated significantly greater mindfulness and self-compassion, and significantly less anxiety, depression, perceived stress and negative affect post-intervention. Additionally, regression results demonstrated that self-compassion and mindfulness predicted decreases in anxiety, depression, perceived stress, and increases in life satisfaction post-intervention. MFY shows promise as a program to increase psychosocial wellbeing in adolescents through increasing mindfulness and self-compassion. Further testing is needed to substantiate the findings. PMID:27110301
Safety testing of lithium cells
NASA Technical Reports Server (NTRS)
Liberto, Nick
1991-01-01
Safety testing is intended to simulate, under laboratory conditions and controls, situations that will subject a cell to externally induced stress. The stresses can occur at any time during the useful life of the cell, from the time of manufacture until it is expended during mission deployment. Abuse testing can be divided into three major categories: Electrical, Mechanical, and Thermal. Although electrical abuses are generally found to occur during handling or deployment, Mechanical and Thermal stresses can be induced during transportation and storage. Therefore, it would be prudent to include predicted environmental exposure as part of the test plan. In the selection of a test program. specific test requirements should be tailored to meet the predicted mission requirements.
Boniolo, Giovanni; D'Agostino, Marcello; Di Fiore, Pier Paolo
2010-03-03
We propose a formal language that allows for transposing biological information precisely and rigorously into machine-readable information. This language, which we call Zsyntax (where Z stands for the Greek word zetaomegaeta, life), is grounded on a particular type of non-classical logic, and it can be used to write algorithms and computer programs. We present it as a first step towards a comprehensive formal language for molecular biology in which any biological process can be written and analyzed as a sort of logical "deduction". Moreover, we illustrate the potential value of this language, both in the field of text mining and in that of biological prediction.
Elevated temperature biaxial fatigue
NASA Technical Reports Server (NTRS)
Jordan, E. H.
1984-01-01
A three year experimental program for studying elevated temperature biaxial fatigue of a nickel based alloy Hastelloy-X has been completed. A new high temperature fatigue test facility with unique capabilities has been developed. Effort was directed toward understanding multiaxial fatigue and correlating the experimental data to the existing theories of fatigue failure. The difficult task of predicting fatigue lives for non-proportional loading was used as an ultimate test for various life prediction methods being considered. The primary means of reaching improved undertanding were through several critical non-proportional loading experiments. It was discovered that the cracking mode switched from primarily cracking on the maximum shear planes at room temperature to cracking on the maximum normal strain planes at 649 C.
Safety testing of lithium cells
NASA Astrophysics Data System (ADS)
Liberto, Nick
1991-05-01
Safety testing is intended to simulate, under laboratory conditions and controls, situations that will subject a cell to externally induced stress. The stresses can occur at any time during the useful life of the cell, from the time of manufacture until it is expended during mission deployment. Abuse testing can be divided into three major categories: Electrical, Mechanical, and Thermal. Although electrical abuses are generally found to occur during handling or deployment, Mechanical and Thermal stresses can be induced during transportation and storage. Therefore, it would be prudent to include predicted environmental exposure as part of the test plan. In the selection of a test program. specific test requirements should be tailored to meet the predicted mission requirements.
Life Sciences Accomplishments 1994
NASA Technical Reports Server (NTRS)
Burnell, Mary Lou (Editor)
1993-01-01
The NASA Life and Biomedical Sciences and Applications Division (LBSAD) serves the Nation's life sciences community by managing all aspects of U.S. space-related life sciences research and technology development. The activities of the Division are integral components of the Nation's overall biological sciences and biomedical research efforts. However, NASA's life sciences activities are unique, in that space flight affords the opportunity to study and characterize basic biological mechanisms in ways not possible on Earth. By utilizing access to space as a research tool, NASA advances fundamental knowledge of the way in which weightlessness, radiation, and other aspects of the space-flight environment interact with biological processes. This knowledge is applied to procedures and technologies that enable humans to live and work in and explore space and contributes to the health and well-being of people on Earth. The activities of the Division are guided by the following three goals: Goal 1) Use microgravity and other unique aspects of the space environment to enhance our understanding of fundamental biological processes. Goal 2) Develop the scientific and technological foundations for supporting exploration by enabling productive human presence in space for extended periods. Goal 3) Apply our unique mission personnel, facilities, and technology to improve education, the quality of life on Earth, and U.S. competitiveness. The Division pursues these goals with integrated ground and flight programs involving the participation of NASA field centers, industry, and universities, as well as interactions with other national agencies and NASA's international partners. The published work of Division-sponsored researchers is a record of completed research in pursuit of these goals. During 1993, the LBSAD instituted significant changes in its experiment solicitation and peer review processes. For the first time, a NASA Research Announcement (NRA) was released requesting proposals for ground-based and flight research for all programs. Areas of particular interest to NASA were defined Proposals due April 29, 1994, will be peer reviewed - externally for scientific merit. This annual NRA process is now the mechanism for recruiting both extramural and intramural investigations. As an overview of LBSAD activities in 1993, this accomplishments document covers each of the major organizational components of the Division and the accomplishments of each. The second section is a review of the Space Life Sciences Research programs Space Biology, Space Physiology and Countermeasures, Radiation Health, Environmental Health, Space Human Factors, Advanced Life Support, and Global Monitoring and Disease Prediction, The third section, Research in Space Flight, describes the substantial contributions of the Spacelab Life Sciences 2 (SLS-2) mission to life sciences research and the significant contributions of the other missions flown in 1993, along with plans for future missions. The Division has greatly expanded and given high priority to its Education and Outreach Programs, which are presented in the fourth section. The fifth and final section, Partners for Space, shows the Divisions Cooperative efforts with other national and international agencies to achieve common goals, along with the accomplishments of joint research and analysis programs.
Hala, D
2017-03-21
The interconnected topology of transcriptional regulatory networks (TRNs) readily lends to mathematical (or in silico) representation and analysis as a stoichiometric matrix. Such a matrix can be 'solved' using the mathematical method of extreme pathway (ExPa) analysis, which identifies uniquely activated genes subject to transcription factor (TF) availability. In this manuscript, in silico multi-tissue TRN models of brain, liver and gonad were used to study reproductive endocrine developmental programming in zebrafish (Danio rerio) from 0.25h post fertilization (hpf; zygote) to 90 days post fertilization (dpf; adult life stage). First, properties of TRN models were studied by sequentially activating all genes in multi-tissue models. This analysis showed the brain to exhibit lowest proportion of co-regulated genes (19%) relative to liver (23%) and gonad (32%). This was surprising given that the brain comprised 75% and 25% more TFs than liver and gonad respectively. Such 'hierarchy' of co-regulatory capability (brain
Brüggemann, Holger; Hagman, Arne; Jules, Matthieu; Sismeiro, Odile; Dillies, Marie-Agnès; Gouyette, Catherine; Kunst, Frank; Steinert, Michael; Heuner, Klaus; Coppée, Jean-Yves; Buchrieser, Carmen
2006-08-01
Adaptation to the host environment and exploitation of host cell functions are critical to the success of intracellular pathogens. Here, insight to these virulence mechanisms was obtained for the first time from the transcriptional program of the human pathogen Legionella pneumophila during infection of its natural host, Acanthamoeba castellanii. The biphasic life cycle of L. pneumophila was reflected by a major shift in gene expression from replicative to transmissive phase, concerning nearly half of the genes predicted in the genome. However, three different L. pneumophila strains showed similar in vivo gene expression patterns, indicating that common regulatory mechanisms govern the Legionella life cycle, despite the plasticity of its genome. During the replicative phase, in addition to components of aerobic metabolism and amino acid catabolism, the Entner-Doudoroff pathway, a NADPH producing mechanism used for sugar and/or gluconate assimilation, was expressed, suggesting for the first time that intracellular L. pneumophila may also scavenge host carbohydrates as nutrients and not only proteins. Identification of genes only upregulated in vivo but not in vitro, may explain higher virulence of in vivo grown L. pneumophila. Late in the life cycle, L. pneumophila upregulates genes predicted to promote transmission and manipulation of a new host cell, therewith priming it for the next attack. These including substrates of the Dot/Icm secretion system, other factors associated previously with invasion and virulence, the motility and the type IV pilus machineries, and > 90 proteins not characterized so far. Analysis of a fliA (sigma28) deletion mutant identified genes coregulated with the flagellar regulon, including GGDEF/EAL regulators and factors that promote host cell entry and survival.
Evaluation of the Meaning of Life Program in Israel
ERIC Educational Resources Information Center
Kasler, Jonathan; White, Gwyne W.; Elias, Maurice J.
2013-01-01
During the 2009-2010 academic year, 10 schools participated in the Meaning of Life educational program, an adaption of the popular U.S. Laws of Life program. The program sought to encourage each participant to develop a personal approach to finding meaning in life. To evaluate the success of the program, we conducted a study to compare measures of…
ERIC Educational Resources Information Center
Acquah, Edward H. K.
2012-01-01
The academic program life cycle (APLC) concept states each program's life flows through several stages: introduction, growth, maturity, and decline. A mixed-influence diffusion growth model is fitted to annual enrollment data on academic programs to analyze the factors determining progress of academic programs through their life cycles. The…
Predictive Medicine: Recombinant DNA Technology and Adult-Onset Genetic Disorders
Hayden, Michael
1988-01-01
Genetic factors are of great importance in common adult-onset disorders such as atherosclerosis, cancer, and neuro-degenerative diseases. Advances in DNA technology now allow identification of persons at high-risk of developing some of these diseases. This advance is leading to predictive medicine. In some genetic disorders, such as those leading to atherosclerosis and cancer, identification of high-risk individuals allows intervention which alters the natural history of the disorder. In other diseases, for which there is no treatment, such as Huntington's disease, the application of this technology provides information that relieves uncertainty and may affect quality of life, but does not alter the course of the illness. General implementation of predictive testing programs awaits the results of pilot projects, which will demonstrate the needs, appropriate levels of support, and guidelines for delivery of such testing. PMID:21253100
Insects in fluctuating thermal environments.
Colinet, Hervé; Sinclair, Brent J; Vernon, Philippe; Renault, David
2015-01-07
All climate change scenarios predict an increase in both global temperature means and the magnitude of seasonal and diel temperature variation. The nonlinear relationship between temperature and biological processes means that fluctuating temperatures lead to physiological, life history, and ecological consequences for ectothermic insects that diverge from those predicted from constant temperatures. Fluctuating temperatures that remain within permissive temperature ranges generally improve performance. By contrast, those which extend to stressful temperatures may have either positive impacts, allowing repair of damage accrued during exposure to thermal extremes, or negative impacts from cumulative damage during successive exposures. We discuss the mechanisms underlying these differing effects. Fluctuating temperatures could be used to enhance or weaken insects in applied rearing programs, and any prediction of insect performance in the field-including models of climate change or population performance-must account for the effect of fluctuating temperatures.
How do Housing Subsidies Improve Quality of Life Among Homeless Adults? A Mediation Analysis.
O'Connell, Maria; Sint, Kyaw; Rosenheck, Robert
2018-03-01
Supported housing, combining rent subsidies with intensive case management, is associated with improvements in quality of life of homeless adults, but factors mediating their impact on quality of life have not been studied. Twelve-month outcome data from a randomized trial of the Housing and Urban Development- Veterans Affairs Supported Housing program (HUD-VASH) showed that access to a housing rent subsidy plus intensive case management (ICM) was associated with greater improvement in subjective quality of life than ICM alone. Multiple mediation analyses were applied to identify variables that significantly mediated the relationship between receipt of housing voucher and improvements in quality of life. Significant mediating covariates were those whose 95% bias-corrected confidence intervals, when added to the model predicting improvement in quality of life, did not overlap zero. Increases in the number of days housed, size of social network, and availability of emotional support appear to mediate improvement in quality of life and account for 71% of the benefit attributable to having a rent subsidy. Improvement in subjective quality of life though housing subsidies is mediated by gains in both material and psychosocial factors. Mediating factors deserve special attention in supported housing services. © Society for Community Research and Action 2018.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Patil, Chinmaya; Naghshtabrizi, Payam; Verma, Rajeev
This paper presents a control strategy to maximize fuel economy of a parallel hybrid electric vehicle over a target life of the battery. Many approaches to maximizing fuel economy of parallel hybrid electric vehicle do not consider the effect of control strategy on the life of the battery. This leads to an oversized and underutilized battery. There is a trade-off between how aggressively to use and 'consume' the battery versus to use the engine and consume fuel. The proposed approach addresses this trade-off by exploiting the differences in the fast dynamics of vehicle power management and slow dynamics of batterymore » aging. The control strategy is separated into two parts, (1) Predictive Battery Management (PBM), and (2) Predictive Power Management (PPM). PBM is the higher level control with slow update rate, e.g. once per month, responsible for generating optimal set points for PPM. The considered set points in this paper are the battery power limits and State Of Charge (SOC). The problem of finding the optimal set points over the target battery life that minimize engine fuel consumption is solved using dynamic programming. PPM is the lower level control with high update rate, e.g. a second, responsible for generating the optimal HEV energy management controls and is implemented using model predictive control approach. The PPM objective is to find the engine and battery power commands to achieve the best fuel economy given the battery power and SOC constraints imposed by PBM. Simulation results with a medium duty commercial hybrid electric vehicle and the proposed two-level hierarchical control strategy show that the HEV fuel economy is maximized while meeting a specified target battery life. On the other hand, the optimal unconstrained control strategy achieves marginally higher fuel economy, but fails to meet the target battery life.« less
How long will my mouse live? Machine learning approaches for prediction of mouse life span.
Swindell, William R; Harper, James M; Miller, Richard A
2008-09-01
Prediction of individual life span based on characteristics evaluated at middle-age represents a challenging objective for aging research. In this study, we used machine learning algorithms to construct models that predict life span in a stock of genetically heterogeneous mice. Life-span prediction accuracy of 22 algorithms was evaluated using a cross-validation approach, in which models were trained and tested with distinct subsets of data. Using a combination of body weight and T-cell subset measures evaluated before 2 years of age, we show that the life-span quartile to which an individual mouse belongs can be predicted with an accuracy of 35.3% (+/-0.10%). This result provides a new benchmark for the development of life-span-predictive models, but improvement can be expected through identification of new predictor variables and development of computational approaches. Future work in this direction can provide tools for aging research and will shed light on associations between phenotypic traits and longevity.
A unified technology plan for fatigue and fracture design
NASA Technical Reports Server (NTRS)
Hardrath, H. F.
1973-01-01
An integrated research program is proposed that seeks to improve the technology of designing against fatigue and fracture and to develop a computerized capability for assessing the adequacy of a given design. Both fatigue life prediction and damage tolerance considerations are incorporated. The research for each of these considerations is organized to account for material behavior, the effect of structural configurations, the cumulative effects of the operating loadings, and for the effects of environment - temperature and corrosion. The goal is to achieve a viable fatigue and fracture design procedure for any practical problem. The overall program is outlined, assessments are made of the state of the art, subgoals are proposed, and means for achieving them are suggested.
NASA Technical Reports Server (NTRS)
Lee, Alice T.; Gunn, Todd; Pham, Tuan; Ricaldi, Ron
1994-01-01
This handbook documents the three software analysis processes the Space Station Software Analysis team uses to assess space station software, including their backgrounds, theories, tools, and analysis procedures. Potential applications of these analysis results are also presented. The first section describes how software complexity analysis provides quantitative information on code, such as code structure and risk areas, throughout the software life cycle. Software complexity analysis allows an analyst to understand the software structure, identify critical software components, assess risk areas within a software system, identify testing deficiencies, and recommend program improvements. Performing this type of analysis during the early design phases of software development can positively affect the process, and may prevent later, much larger, difficulties. The second section describes how software reliability estimation and prediction analysis, or software reliability, provides a quantitative means to measure the probability of failure-free operation of a computer program, and describes the two tools used by JSC to determine failure rates and design tradeoffs between reliability, costs, performance, and schedule.
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.
Manikandan, Narayanan; Subha, Srinivasan
2016-01-01
Software development life cycle has been characterized by destructive disconnects between activities like planning, analysis, design, and programming. Particularly software developed with prediction based results is always a big challenge for designers. Time series data forecasting like currency exchange, stock prices, and weather report are some of the areas where an extensive research is going on for the last three decades. In the initial days, the problems with financial analysis and prediction were solved by statistical models and methods. For the last two decades, a large number of Artificial Neural Networks based learning models have been proposed to solve the problems of financial data and get accurate results in prediction of the future trends and prices. This paper addressed some architectural design related issues for performance improvement through vectorising the strengths of multivariate econometric time series models and Artificial Neural Networks. It provides an adaptive approach for predicting exchange rates and it can be called hybrid methodology for predicting exchange rates. This framework is tested for finding the accuracy and performance of parallel algorithms used.
Manikandan, Narayanan; Subha, Srinivasan
2016-01-01
Software development life cycle has been characterized by destructive disconnects between activities like planning, analysis, design, and programming. Particularly software developed with prediction based results is always a big challenge for designers. Time series data forecasting like currency exchange, stock prices, and weather report are some of the areas where an extensive research is going on for the last three decades. In the initial days, the problems with financial analysis and prediction were solved by statistical models and methods. For the last two decades, a large number of Artificial Neural Networks based learning models have been proposed to solve the problems of financial data and get accurate results in prediction of the future trends and prices. This paper addressed some architectural design related issues for performance improvement through vectorising the strengths of multivariate econometric time series models and Artificial Neural Networks. It provides an adaptive approach for predicting exchange rates and it can be called hybrid methodology for predicting exchange rates. This framework is tested for finding the accuracy and performance of parallel algorithms used. PMID:26881271
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.
Experimental and theoretical investigation of fatigue life in reusable rocket thrust chambers
NASA Technical Reports Server (NTRS)
Hannum, N. P.; Kasper, H. J.; Pavli, A. J.
1976-01-01
During a test program to investigate low-cycle thermal fatigue, 13 rocket combustion chambers were fabricated and cyclically test fired to failure. Six oxygen-free, high-conductivity (OFHC) copper and seven Amzirc chambers were tested. The failures in the OFHC copper chambers were not typical fatigue failures but are described as creep rupture enhanced by ratcheting. The coolant channels bulged toward the chamber centerline, resulting in progressive thinning of the wall during each cycle. The failures in the Amzirc alloy chambers were caused by low-cycle thermal fatigue. The zirconium in this alloy was not evenly distributed in the chamber materials. The life that was achieved was nominally the same as would have been predicted from OFHC copper isothermal test data.
Subjective Life Expectancy Among College Students.
Rodemann, Alyssa E; Arigo, Danielle
2017-09-14
Establishing healthy habits in college is important for long-term health. Despite existing health promotion efforts, many college students fail to meet recommendations for behaviors such as healthy eating and exercise, which may be due to low perceived risk for health problems. The goals of this study were to examine: (1) the accuracy of life expectancy predictions, (2) potential individual differences in accuracy (i.e., gender and conscientiousness), and (3) potential change in accuracy after inducing awareness of current health behaviors. College students from a small northeastern university completed an electronic survey, including demographics, initial predictions of their life expectancy, and their recent health behaviors. At the end of the survey, participants were asked to predict their life expectancy a second time. Their health data were then submitted to a validated online algorithm to generate calculated life expectancy. Participants significantly overestimated their initial life expectancy, and neither gender nor conscientiousness was related to the accuracy of these predictions. Further, subjective life expectancy decreased from initial to final predictions. These findings suggest that life expectancy perceptions present a unique-and potentially modifiable-psychological process that could influence college students' self-care.
Hermens, Niels; Super, Sabina; Verkooijen, Kirsten T; Koelen, Maria A
2017-12-01
Despite the strong belief in sports programs as a setting in which socially vulnerable youth can develop life skills, no overview exists of life skill development in sports programs serving this youth group. Therefore, the present systematic review provides an overview of the evidence on life skill development in sports programs serving socially vulnerable youth and, insofar as it was investigated in the included studies, of the conditions conducive to life skill development in these sports programs. Potentially relevant studies published during 1990 to 2014 were identified by a search in 7 electronic databases. The search combined terms relating to (a) sport, (b) youth AND socially vulnerable, and (c) life skills. Eighteen of the 2,076 unique studies met the inclusion criteria. Each included study reported that at least 1 life skill improved in youth who participated in the studied sports program. Improvements in cognitive and social life skills were more frequently reported than were improvements in emotional life skills. Only a few of the included studies investigated the conditions in the studied sports programs that made these programs conducive to life skill development. Sports programs have the potential to make a difference in the life skill development of socially vulnerable youth. This conclusion needs to be treated with some caution, because the studies experienced many challenges in reducing the risk for bias. Several alternative research strategies are suggested for future studies in this field.
Computerized atmospheric trace contaminant control simulation for manned spacecraft
NASA Technical Reports Server (NTRS)
Perry, J. L.
1993-01-01
Buildup of atmospheric trace contaminants in enclosed volumes such as a spacecraft may lead to potentially serious health problems for the crew members. For this reason, active control methods must be implemented to minimize the concentration of atmospheric contaminants to levels that are considered safe for prolonged, continuous exposure. Designing hardware to accomplish this has traditionally required extensive testing to characterize and select appropriate control technologies. Data collected since the Apollo project can now be used in a computerized performance simulation to predict the performance and life of contamination control hardware to allow for initial technology screening, performance prediction, and operations and contingency studies to determine the most suitable hardware approach before specific design and testing activities begin. The program, written in FORTRAN 77, provides contaminant removal rate, total mass removed, and per pass efficiency for each control device for discrete time intervals. In addition, projected cabin concentration is provided. Input and output data are manipulated using commercial spreadsheet and data graphing software. These results can then be used in analyzing hardware design parameters such as sizing and flow rate, overall process performance and program economics. Test performance may also be predicted to aid test design.
Cultural variation in the use of current life satisfaction to predict the future.
Oishi, S; Wyer, R S; Colcombe, S J
2000-03-01
Three studies examined cultural and situational influences on the tendency for people to use their current life satisfaction to predict future life events. On the basis of the self-enhancement literature, it was predicted that either writing about a positive personal experience or reading about another's negative experience would lead European Americans to focus their attention on internal attributes and thus would lead them to use their current life satisfaction in predicting the future. Conversely, on the basis of the self-criticism literature, it was predicted that these same conditions would lead Asian Americans to focus their attention on external factors and, therefore, would decrease their likelihood of using their current life satisfaction to predict the future. Studies 1 and 2 supported these hypotheses. Study 3 showed that these patterns could be obtained by subliminally priming concepts associated with individualism and collectivism.
Marsillas, Sara; De Donder, Liesbeth; Kardol, Tinie; van Regenmortel, Sofie; Dury, Sarah; Brosens, Dorien; Smetcoren, An-Sofie; Braña, Teresa; Varela, Jesús
2017-09-01
Several debates have emerged across the literature about the conceptualisation of active ageing. The aim of this study is to develop a model of the construct that is focused on the individual, including different elements of people's lives that have the potential to be modified by intervention programs. Moreover, the paper examines the contributions of active ageing to life satisfaction, as well as the possible predictive role of coping styles on active ageing. For this purpose, a representative sample of 404 Galician (Spain) community-dwelling older adults (aged ≥60 years) were interviewed using a structured survey. The results demonstrate that the proposed model composed of two broad categories is valid. The model comprises status variables (related to physical, psychological, and social health) as well as different types of activities, called processual variables. This model is tested using partial least squares (PLS) regression. The findings show that active ageing is a fourth-order, formative construct. In addition, PLS analyses indicate that active ageing has a moderate and positive path on life satisfaction and that coping styles may predict active ageing. The discussion highlights the potential of active ageing as a relevant concept for people's lives, drawing out policy implications and suggestions for further research.
Gambling, Drinking and Quality of Life: Evidence from Macao and Australia.
Loo, Jasmine M Y; Shi, Yongdong; Pu, Xiaohong
2016-06-01
The investigation of the interface between psychological constructs, compulsive consumption of alcohol and pathological gambling is an important avenue for development of future initiatives in social marketing or prevention programs. This cross-cultural study attempts to bridge the gap in literature by providing an evaluation of the predictive ability of psychological variables such as gambling urge, gambling-related erroneous cognitions and comorbid alcohol consumption on pathological gambling behaviour and its impact on overall quality of life indicators. Participants consist of 445 Macao and Australian young adults (Mean age = 23 years). Results indicate that probable pathological gamblers as compared with non-gamblers reported significantly lower quality of life in all domains-physical health, psychological well-being, social relationships and environment. Adults who drank more alcohol and have stronger erroneous cognitions evidenced higher pathological gambling behavior. Our research model fits both cohorts and interestingly, erroneous gambling-related cognitions serve as a full mediator for the predictive relationship between gambling urge and pathological gambling in the Macao sample, but serve as a partial mediator in the Australian sample. Targeting erroneous cognitions in future social marketing or preventive campaigns should demonstrate to be an important strategy in reducing the effects of urge to gamble among at-risk individuals. Further implications for the industry, marketing and governmental strategies are discussed.
NASA Technical Reports Server (NTRS)
Razzaq, Zia
1989-01-01
Straight or curved hat-section members are often used as structural stiffeners in aircraft. For instance, they are employed as stiffeners for the dorsal skin as well as in the aerial refueling adjacent area structure in F-106 aircraft. The flanges of the hat-section are connected to the aircraft skin. Thus, the portion of the skin closing the hat-section interacts with the section itself when resisting the stresses due to service loads. The flexural fatigue life of such a closed section is estimated using materially nonlinear axial fatigue characteristics. It should be recognized that when a structural shape is subjected to bending, the fatigue life at the neutral axis is infinity since the normal stresses are zero at that location. Conversely, the fatigue life at the extreme fibers where the normal bending stresses are maximum can be expected to be finite. Thus, different fatigue life estimates can be visualized at various distances from the neural axis. The problem becomes compounded further when significant portions away from the neutral axis are stressed into plastic range. A theoretical analysis of the closed hat-section subjected to flexural cyclic loading is first conducted. The axial fatigue characteristics together with the related axial fatigue life formula and its inverted form given by Manson and Muralidharan are adopted for an aluminum alloy used in aircraft construction. A closed-form expression for predicting the flexural fatigue life is then derived for the closed hat-section including materially nonlinear action. A computer program is written to conduct a study of the variables such as the thicknesses of the hat-section and the skin, and the type of alloy used. The study has provided a fundamental understanding of the flexural fatigue life characteristics of a practical structural component used in aircraft when materially nonlinear action is present.
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.
Yang, Zheng; Zadjura, Lisa M; Marino, Anthony M; D'Arienzo, Celia J; Malinowski, Jacek; Gesenberg, Christoph; Lin, Pin-Fang; Colonno, Richard J; Wang, Tao; Kadow, John F; Meanwell, Nicholas A; Hansel, Steven B
2010-04-01
Optimizing pharmacokinetic properties to improve oral exposure is a common theme in modern drug discovery. In the present work, in vitro Caco-2 permeability and microsomal half-life screens were utilized in an effort to guide the structure-activity relationship in order to improve the pharmacokinetic properties of novel HIV-1 attachment inhibitors. The relevance of the in vitro screens to in vivo pharmacokinetic properties was first demonstrated with a number of program compounds at the early stage of lead optimization. The Caco-2 permeability, tested at 200 microM, was quantitatively predictive of in vivo oral absorption, with complete absorption occurring at a Caco-2 permeability of 100 nm/s or higher. The liver microsomal half-life screen, conducted at 1 microM substrate concentration, can readily differentiate low-, intermediate-, and high-clearance compounds in rats, with a nearly 1:1 correlation in 12 out of 13 program compounds tested. Among the >100 compounds evaluated, BMS-488043 emerged as a lead, exhibiting a Caco-2 permeability of 178 nm/s and a microsomal half-life predictive of a low clearance (4 mL/min/kg) in humans. These in vitro characteristics translated well to the in vivo setting. The oral bioavailability of BMS-488043 in rats, dogs, and monkeys was 90%, 57%, and 60%, respectively. The clearance was low in all three species tested, with a terminal half-life ranging from 2.4 to 4.7 h. Furthermore, the oral exposure of BMS-488043 was significantly improved (6- to 12-fold in rats and monkeys) compared to the prototype compound BMS-378806 that had a suboptimal Caco-2 permeability (51 nm/s) and microsomal half-life. More importantly, the improvements in preclinical pharmacokinetics translated well to humans, leading to a >15-fold increase in the human oral exposure of BMS-488043 than BMS-378806 and enabling a clinical proof-of-concept for this novel class of anti-HIV agents. The current studies demonstrated the valuable role of in vitro ADME screens in improving oral pharmacokinetics at the lead optimization stage. 2009 Wiley-Liss, Inc. and the American Pharmacists Association
Lee, Okseon; Park, Mirim; Jang, Kyunghwan; Park, Yongnam
2017-12-01
The purpose of this study was to investigate the influence of an afterschool sport program on adolescents' life skills development and to identify which characteristics of the program would have an influence on their life skills acquisition. The participants were six children (4 boys, 2 girls) who participated in a 12-week afterschool program implemented in two elementary schools, as well as the two program instructors who implemented the afterschool sport program. Data were collected from individual interviews with program participants and instructors. The inductive analysis of data revealed four categories of life skills developed through program participation: (1) playing well and being more active, (2) connecting well and having better social skills, (3) coping well and becoming a better problem solver, and (4) dreaming well and having a better sense of purpose. Regarding the characteristics of the program that influenced life skills development, three themes emerged: (1) having a clear goal and building consensus with stakeholders, (2) establishing a firm yet flexible structure, and (3) instructors' use of effective strategies for teaching life skills.
Lee, Okseon; Park, Mirim; Jang, Kyunghwan; Park, Yongnam
2017-01-01
ABSTRACT The purpose of this study was to investigate the influence of an afterschool sport program on adolescents’ life skills development and to identify which characteristics of the program would have an influence on their life skills acquisition. The participants were six children (4 boys, 2 girls) who participated in a 12-week afterschool program implemented in two elementary schools, as well as the two program instructors who implemented the afterschool sport program. Data were collected from individual interviews with program participants and instructors. The inductive analysis of data revealed four categories of life skills developed through program participation: (1) playing well and being more active, (2) connecting well and having better social skills, (3) coping well and becoming a better problem solver, and (4) dreaming well and having a better sense of purpose. Regarding the characteristics of the program that influenced life skills development, three themes emerged: (1) having a clear goal and building consensus with stakeholders, (2) establishing a firm yet flexible structure, and (3) instructors’ use of effective strategies for teaching life skills. PMID:28367697
Design to Cost and Life Cycle Cost.
1980-07-01
The data are also based on a sample of reporting squadrons. Though the VAMOSC MS offers an excellent capability to deal with design-related issues...levels as predictions in the early design phase of a program. Figure 4 presents sample FY-78 costs from the VAMOSC MS report. The costs are on a cost...equlipmlent before attachlmenlt to adjacent sectionls. Ibis allows tile work tol be performed within thC reachl of tile most1 efficient equipment and w4ithl
1981-04-01
are listed in Appendix B. There was a significant problem with the formal auditing of the NEPTUNE predictions since a complete manual checking effort...WRSE R. Z. ien BROKLY ! ACcA BSTON SATH CROTON SAT VALJLJO OUZ~A 5.3. NW AD AX A’s AMS AOFT AG! AZ AOSS AD "’s A AS& ASI AT! A’S AVM cc C"~ Cv DC OD963
1991-12-21
itself. For example, in the case of turbine wheel /blade inspection, remotely obtained blade fatigue data coupled with a life prediction model and...Security, etc. C 2. T/C Assembly for Evidence of Coolant Passage Blockage C 3. HPFTP Turbine Wheel /Blades for Cracks, Fatigue and Damage C 4. HPOTP Turbine... Wheel /Blades for Cracks, Fatigue and Damage C 5. LPFTP Turbine Wheel /Blades for Cracks, Fatigue and Damage C 6. LPOTP Turbine Wheel /Blades for Cracks
Further Validation of the Pathways Housing First Fidelity Scale.
Goering, Paula; Veldhuizen, Scott; Nelson, Geoffrey B; Stefancic, Ana; Tsemberis, Sam; Adair, Carol E; Distasio, Jino; Aubry, Tim; Stergiopoulos, Vicky; Streiner, David L
2016-01-01
This study examined whether Housing First fidelity ratings correspond to program operation descriptions from administrative data and predict client outcomes. A multisite, randomized controlled trial (At Home/Chez Soi) in five Canadian cities included two assessments of 12 programs over two years. Outcomes for 1,158 clients were measured every six months. Associations between fidelity ratings and administrative data (Spearman correlations) and participant outcomes (mixed-effects modeling) were examined. Fidelity ratings were generally good (mean ± SD=136.6 ± 10.3 out of a possible range of 38-152; 87% of maximum value). Fidelity was significantly associated with three of four measures of program operation, with correlations between .55 and .60. Greater program fidelity was associated with improvement in housing stability, community functioning, and quality of life. Variation in program fidelity was associated with operations and outcomes, supporting scale validity and intervention effectiveness. These findings reinforced the value of using fidelity monitoring to conduct quality assurance and technical assistance activities.
ERIC Educational Resources Information Center
Hermens, Niels; Super, Sabina; Verkooijen, Kirsten T.; Koelen, Maria A.
2017-01-01
Purpose: Despite the strong belief in sports programs as a setting in which socially vulnerable youth can develop life skills, no overview exists of life skill development in sports programs serving this youth group. Therefore, the present systematic review provides an overview of the evidence on life skill development in sports programs serving…
The Impact of a Sport-Based Life Skill Program on Adolescent Prosocial Values
ERIC Educational Resources Information Center
Brunelle, John; Danish, Steven J.; Forneris, Tanya
2007-01-01
This article describes the implementation and evaluation of a sport-based life skills and community service program. The purpose of this investigation was to determine the impact of a combined life skills and community service program on adolescents' prosocial values. The program was part of a national golf and life skills enrichment academy for…
For Whom the Mind Wanders, and When, Varies Across Laboratory and Daily-Life Settings.
Kane, Michael J; Gross, Georgina M; Chun, Charlotte A; Smeekens, Bridget A; Meier, Matt E; Silvia, Paul J; Kwapil, Thomas R
2017-09-01
Undergraduates ( N = 274) participated in a weeklong daily-life experience-sampling study of mind wandering after being assessed in the lab for executive-control abilities (working memory capacity; attention-restraint ability; attention-constraint ability; and propensity for task-unrelated thoughts, or TUTs) and personality traits. Eight times a day, electronic devices prompted subjects to report on their current thoughts and context. Working memory capacity and attention abilities predicted subjects' TUT rates in the lab, but predicted the frequency of daily-life mind wandering only as a function of subjects' momentary attempts to concentrate. This pattern replicates prior daily-life findings but conflicts with laboratory findings. Results for personality factors also revealed different associations in the lab and daily life: Only neuroticism predicted TUT rate in the lab, but only openness predicted mind-wandering rate in daily life (both predicted the content of daily-life mind wandering). Cognitive and personality factors also predicted dimensions of everyday thought other than mind wandering, such as subjective judgments of controllability of thought. Mind wandering in people's daily environments and TUTs during controlled and artificial laboratory tasks have different correlates (and perhaps causes). Thus, mind-wandering theories based solely on lab phenomena may be incomplete.
Walther, Dirk; Bartha, Gábor; Morris, Macdonald
2001-01-01
A pivotal step in electrophoresis sequencing is the conversion of the raw, continuous chromatogram data into the actual sequence of discrete nucleotides, a process referred to as basecalling. We describe a novel algorithm for basecalling implemented in the program LifeTrace. Like Phred, currently the most widely used basecalling software program, LifeTrace takes processed trace data as input. It was designed to be tolerant to variable peak spacing by means of an improved peak-detection algorithm that emphasizes local chromatogram information over global properties. LifeTrace is shown to generate high-quality basecalls and reliable quality scores. It proved particularly effective when applied to MegaBACE capillary sequencing machines. In a benchmark test of 8372 dye-primer MegaBACE chromatograms, LifeTrace generated 17% fewer substitution errors, 16% fewer insertion/deletion errors, and 2.4% more aligned bases to the finished sequence than did Phred. For two sets totaling 6624 dye-terminator chromatograms, the performance improvement was 15% fewer substitution errors, 10% fewer insertion/deletion errors, and 2.1% more aligned bases. The processing time required by LifeTrace is comparable to that of Phred. The predicted quality scores were in line with observed quality scores, permitting direct use for quality clipping and in silico single nucleotide polymorphism (SNP) detection. Furthermore, we introduce a new type of quality score associated with every basecall: the gap-quality. It estimates the probability of a deletion error between the current and the following basecall. This additional quality score improves detection of single basepair deletions when used for locating potential basecalling errors during the alignment. We also describe a new protocol for benchmarking that we believe better discerns basecaller performance differences than methods previously published. PMID:11337481
Darrington, Richard T; Jiao, Jim
2004-04-01
Rapid and accurate stability prediction is essential to pharmaceutical formulation development. Commonly used stability prediction methods include monitoring parent drug loss at intended storage conditions or initial rate determination of degradants under accelerated conditions. Monitoring parent drug loss at the intended storage condition does not provide a rapid and accurate stability assessment because often <0.5% drug loss is all that can be observed in a realistic time frame, while the accelerated initial rate method in conjunction with extrapolation of rate constants using the Arrhenius or Eyring equations often introduces large errors in shelf-life prediction. In this study, the shelf life prediction of a model pharmaceutical preparation utilizing sensitive high-performance liquid chromatography-mass spectrometry (LC/MS) to directly quantitate degradant formation rates at the intended storage condition is proposed. This method was compared to traditional shelf life prediction approaches in terms of time required to predict shelf life and associated error in shelf life estimation. Results demonstrated that the proposed LC/MS method using initial rates analysis provided significantly improved confidence intervals for the predicted shelf life and required less overall time and effort to obtain the stability estimation compared to the other methods evaluated. Copyright 2004 Wiley-Liss, Inc. and the American Pharmacists Association.
Early-Life Nutritional Programming of Health and Disease in The Gambia.
Moore, Sophie E
2017-01-01
Exposures during early life are increasingly being recognised as factors that play an important role in the aetiology of chronic non-communicable diseases (NCDs). The "Developmental Origins of Health and Disease" (DOHaD) hypothesis asserts that adverse early-life exposures - most notably unbalanced nutrition - leads to an increased risk for a range of NCDs and that disease risk is highest when there is a "mismatch" between the early- and later-life environments. Thus, the DOHaD hypothesis would predict highest risk in settings undergoing a rapid nutrition transition. We investigated the link between early-life nutritional exposures and long-term health in rural Gambia, West Africa. Using demographic data dating back to the 1940s, the follow-up of randomised controlled trials of nutritional supplementation in pregnancy, and the "experiment of nature" that seasonality in this region provides, we investigated the DOHaD hypothesis in a population with high rates of maternal and infant under-nutrition, a high burden from infectious disease, and an emerging risk of NCDs. Key Messages: Our work in rural Gambia suggests that in populations with high rates of under-nutrition in early life, the immune system may be sensitive to nutritional deficiencies early in life, resulting in a greater susceptibility to infection-related morbidity and mortality. © 2017 S. Karger AG, Basel.
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
Alleged sexual abuse at a day care center: impact on parents.
Dyb, Grete; Holen, Are; Steinberg, Alan M; Rodriguez, Ned; Pynoos, Robert S
2003-08-01
This report describes the cascade of stressful events and secondary life changes experienced by parents in a case of alleged sexual abuse at a day care program. The study evaluated parents' Posttraumatic Stress Disorder (PTSD) symptoms and general psychological responses to the stressful events 4 years after the alleged abuse, and explored predictive factors of parental distress. A total of 39 parents were interviewed about stressful events, life changes, and social support. Current distress reactions, psychological wellbeing, and locus of control were assessed with a battery of standardized measures. Hearing about the sexual abuse, testifying in court, hearing the verdict, and being exposed in media reports were all rated by the parents as distressing events. The majority of the parents experienced secondary life changes after the alleged sexual abuse. Four years after the alleged sexual abuse, one-third of the parents reported a high level of PTSD Intrusive symptoms and one-fourth reported a high level of PTSD Avoidance symptoms. There was a significant positive correlation between a measure of psychological wellbeing and PTSD. Secondary life changes and locus of control significantly predicted PTSD. This study demonstrates that the alleged sexual abuse of children in day care and the resulting events in the legal system and the media constitute significant and chronic stressors in the lives of the children's parents. These findings underscore the need to expand the focus of trauma-related sequelae from the child victim to their parents and family.
Advanced Simulation and Computing Fiscal Year 14 Implementation Plan, Rev. 0.5
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meisner, Robert; McCoy, Michel; Archer, Bill
2013-09-11
The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of experimental facilities and programs, and the computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities andmore » computational resources that support annual stockpile assessment and certification, study advanced nuclear weapons design and manufacturing processes, analyze accident scenarios and weapons aging, and provide the tools to enable stockpile Life Extension Programs (LEPs) and the resolution of Significant Finding Investigations (SFIs). This requires a balanced resource, including technical staff, hardware, simulation software, and computer science solutions. In its first decade, the ASC strategy focused on demonstrating simulation capabilities of unprecedented scale in three spatial dimensions. In its second decade, ASC is now focused on increasing predictive capabilities in a three-dimensional (3D) simulation environment while maintaining support to the SSP. The program continues to improve its unique tools for solving progressively more difficult stockpile problems (sufficient resolution, dimensionality, and scientific details), quantify critical margins and uncertainties, and resolve increasingly difficult analyses needed for the SSP. Moreover, ASC’s business model is integrated and focused on requirements-driven products that address long-standing technical questions related to enhanced predictive capability in the simulation tools.« less
Sun, Yazhen; Fang, Chenze; Wang, Jinchang; Yuan, Xuezhong; Fan, Dong
2018-05-03
Laboratory predictions for the fatigue life of an asphalt mixture under cyclic loading based on the plateau value (PV) of the permanent deformation ratio (PDR) were carried out by three-point bending fatigue tests. The influence of test conditions on the recovery ratio of elastic deformation (RRED), the permanent deformation (PD) and PDR, and the trends of RRED, PD, and PDR were studied. The damage variable was defined by using PDR, and the relation of the fatigue life to PDR was determined by analyzing the damage evolution process. The fatigue equation was established based on the PV of PDR and the fatigue life was predicted by analyzing the relation of the fatigue life to the PV. The results show that the RRED decreases with the increase of the number of loading cycles, and the elastic recovery ability of the asphalt mixture gradually decreases. The two mathematical models proposed are based on the change laws of the RRED, and the PD can well describe the change laws. The RRED or the PD cannot well predict the fatigue life because they do not change monotonously with the fatigue life, and one part of the deformation causes the damage and the other part causes the viscoelastic deformation. The fatigue life decreases with the increase of the PDR. The average PDR in the second stage is taken as the PV, and the fatigue life decreases in a power law with the increase of the PV. The average relative error of the fatigue life predicted by the fatigue equation to the test fatigue life is 5.77%. The fatigue equation based on PV can well predict the fatigue life.
The Technology in the Programs of Life Sciences in Turkey and Sachunterricht in Germany
ERIC Educational Resources Information Center
Keskin, Tuba
2017-01-01
The purpose of this study is to compare the gains of the Life Sciences program in Turkey and the Life sciences program (Sachunterricht) used in the state of Niedersachsen in Germany. The study aiming to compare the technology-related acquisitions in Life sciences program in Turkey and Germany is a comparative education research that used…
Gender Differences in Contextual Predictors of Urban, Early Adolescents' Subjective Well-Being
ERIC Educational Resources Information Center
Vera, Elizabeth M.; Moallem, B. Isabel; Vacek, Kimberly R.; Blackmon, Sha'kema; Coyle, Laura D.; Gomez, Kenia L.; Lamp, Kristen; Langrehr, Kimberly J.; Luginbuhl, Paula; Mull, Megan K.; Telander, Kyle J.; Steele, J. Corey
2012-01-01
Gender differences in predicting subjective well-being (SWB) were examined in 168 urban adolescents. School satisfaction predicted life satisfaction for boys; for girls, family satisfaction predicted life satisfaction and neighborhood satisfaction predicted negative affect. Self-esteem predicted positive affect for both genders, but friends…
Life prediction of thermal-mechanical fatigue using strainrange partitioning
NASA Technical Reports Server (NTRS)
Halford, G. R.; Manson, S. S.
1975-01-01
This paper describes the applicability of the method of Strainrange Partitioning to the life prediction of thermal-mechanical strain-cycling fatigue. An in-phase test on 316 stainless steel is analyzed as an illustrative example. The observed life is in excellent agreement with the life predicted by the method using the recently proposed Step-Stress Method of experimental partitioning, the Interaction Damage Rule, and the life relationships determined at an isothermal temperature of 705 C. Implications of the present study are discussed relative to the general thermal fatigue problem.
Life prediction of thermal-mechanical fatigue using strain-range partitioning
NASA Technical Reports Server (NTRS)
Halford, G. R.; Manson, S. S.
1975-01-01
The applicability is described of the method of Strainrange Partitioning to the life prediction of thermal-mechanical strain-cycling fatigue. An in-phase test on 316 stainless steel is analyzed as an illustrative example. The observed life is in excellent agreement with the life predicted by the method using the recently proposed Step-Stress Method of experimental partitioning, the Interation Damage Rule, and the life relationships determined at an isothermal temperature of 705 C. Implications of the study are discussed relative to the general thermal fatigue problem.
Coupling sensing to crop models for closed-loop plant production in advanced life support systems
NASA Astrophysics Data System (ADS)
Cavazzoni, James; Ling, Peter P.
1999-01-01
We present a conceptual framework for coupling sensing to crop models for closed-loop analysis of plant production for NASA's program in advanced life support. Crop status may be monitored through non-destructive observations, while models may be independently applied to crop production planning and decision support. To achieve coupling, environmental variables and observations are linked to mode inputs and outputs, and monitoring results compared with model predictions of plant growth and development. The information thus provided may be useful in diagnosing problems with the plant growth system, or as a feedback to the model for evaluation of plant scheduling and potential yield. In this paper, we demonstrate this coupling using machine vision sensing of canopy height and top projected canopy area, and the CROPGRO crop growth model. Model simulations and scenarios are used for illustration. We also compare model predictions of the machine vision variables with data from soybean experiments conducted at New Jersey Agriculture Experiment Station Horticulture Greenhouse Facility, Rutgers University. Model simulations produce reasonable agreement with the available data, supporting our illustration.
Momentary affect predicts bodily movement in daily life: an ambulatory monitoring study.
Schwerdtfeger, Andreas; Eberhardt, Ragna; Chmitorz, Andrea; Schaller, Eva
2010-10-01
There is converging evidence that physical activity influences affective states. It has been found that aerobic exercise programs can significantly diminish negative affect. Moreover, among healthy individuals, moderate levels of physical activity seem to increase energetic arousal and positive affect. However, the predictive utility of affective states for bodily movement has rarely been investigated. In this study, we examined whether momentarily assessed affect is associated with bodily movement in everyday life. Using a previously published data set (Schwerdtfeger, Eberhardt, & Chmitorz, 2008), we reanalyzed 12-hr ecological momentary assessment (EMA) data from 124 healthy volunteers. Electronic momentary positive-activated affect (EMA-PAA) and negative affect (EMA-NA) were assessed via handheld computers, and bodily movement was recorded via accelerosensors. Generalized linear mixed models were calculated. Results indicated that EMAPAA increases were accompanied by bodily movement increases of varying intensity. EMA-NA was also positively associated with increases in certain kinds of bodily movement. In light of previous research, this finding suggests that affect and bodily movement may have circular effects on each other.
Paul, Lisa A.; Kehn, Andre; Gray, Matt J.; Salapska-Gelleri, Joanna
2014-01-01
Objective Undergraduate rape disclosure recipients and nonrecipients’ sociodemographic and life experience variables, attitudes towards rape and responses to a hypothetical rape disclosure were compared to determine differences between them. Participants One-hundred-ninety-two undergraduates at three universities participated in this online survey between November 2011 – April 2012. Methods Participants reported on their rape myth acceptance (RMA) and personal direct and indirect (i.e., disclosure receipt) experiences with sexual assault. Participants also responded to a hypothetical rape disclosure. Results Disclosure recipients were more likely to report a victimization history, and less confusion and perceived ineffectiveness in helping the hypothetical victim. RMA and nonrecipient status predicted perceived victim responsibility; these variables and childhood victimization predicted confusion about helping. RMA also predicted perceived ineffectiveness of one’s helping behaviors. Victimization history and female gender predicted victim empathy. Conclusions These findings can inform sexual assault-related programming for undergraduates through the provision of targeted assistance and corrective information. PMID:24779405
Thomsen, Dorthe Kirkegaard; Jensen, Thomas; Holm, Tine; Olesen, Martin Hammershøj; Schnieber, Anette; Tønnesvang, Jan
2015-11-01
Forty-five participants described and rated two events each week during their first term at university. After 3.5 years, we examined whether event characteristics rated in the diary predicted remembering, reliving, and life story importance at the follow-up. In addition, we examined whether ratings of life story importance were consistent across a three year interval. Approximately 60% of events were remembered, but only 20% of these were considered above medium importance to life stories. Higher unusualness, rehearsal, and planning predicted whether an event was remembered 3.5 years later. Higher goal-relevance, importance, emotional intensity, and planning predicted life story importance 3.5 years later. There was a moderate correlation between life story importance rated three months after the diary and rated at the 3.5 year follow-up. The results suggest that autobiographical memory and life stories are governed by different mechanisms and that life story memories are characterized by some degree of stability. Copyright © 2015 Elsevier Inc. All rights reserved.
2016-01-01
Background Several approaches to reduce the incidence of invasive cervical cancers exist. The approach adopted should take into account contextual factors that influence the cost-effectiveness of the available options. Objective To determine the cost-effectiveness of screening strategies combined with a vaccination program for 10-year old girls for cervical cancer prevention in Vientiane, Lao PDR. Methods A population-based dynamic compartment model was constructed. The interventions consisted of a 10-year old girl vaccination program only, or this program combined with screening strategies, i.e., visual inspection with acetic acid (VIA), cytology-based screening, rapid human papillomavirus (HPV) DNA testing, or combined VIA and cytology testing. Simulations were run over 100 years. In base-case scenario analyses, we assumed a 70% vaccination coverage with lifelong protection and a 50% screening coverage. The outcome of interest was the incremental cost per Disability-Adjusted Life Year (DALY) averted. Results In base-case scenarios, compared to the next best strategy, the model predicted that VIA screening of women aged 30–65 years old every three years, combined with vaccination, was the most attractive option, costing 2 544 international dollars (I$) per DALY averted. Meanwhile, rapid HPV DNA testing was predicted to be more attractive than cytology-based screening or its combination with VIA. Among cytology-based screening options, combined VIA with conventional cytology testing was predicted to be the most attractive option. Multi-way sensitivity analyses did not change the results. Compared to rapid HPV DNA testing, VIA had a probability of cost-effectiveness of 73%. Compared to the vaccination only option, the probability that a program consisting of screening women every five years would be cost-effective was around 60% and 80% if the willingness-to-pay threshold is fixed at one and three GDP per capita, respectively. Conclusions A VIA screening program in addition to a girl vaccination program was predicted to be the most attractive option in the health care context of Lao PDR. When compared with other screening methods, VIA was the primary recommended method for combination with vaccination in Lao PDR. PMID:27631732
Chanthavilay, Phetsavanh; Reinharz, Daniel; Mayxay, Mayfong; Phongsavan, Keokedthong; Marsden, Donald E; Moore, Lynne; White, Lisa J
2016-01-01
Several approaches to reduce the incidence of invasive cervical cancers exist. The approach adopted should take into account contextual factors that influence the cost-effectiveness of the available options. To determine the cost-effectiveness of screening strategies combined with a vaccination program for 10-year old girls for cervical cancer prevention in Vientiane, Lao PDR. A population-based dynamic compartment model was constructed. The interventions consisted of a 10-year old girl vaccination program only, or this program combined with screening strategies, i.e., visual inspection with acetic acid (VIA), cytology-based screening, rapid human papillomavirus (HPV) DNA testing, or combined VIA and cytology testing. Simulations were run over 100 years. In base-case scenario analyses, we assumed a 70% vaccination coverage with lifelong protection and a 50% screening coverage. The outcome of interest was the incremental cost per Disability-Adjusted Life Year (DALY) averted. In base-case scenarios, compared to the next best strategy, the model predicted that VIA screening of women aged 30-65 years old every three years, combined with vaccination, was the most attractive option, costing 2 544 international dollars (I$) per DALY averted. Meanwhile, rapid HPV DNA testing was predicted to be more attractive than cytology-based screening or its combination with VIA. Among cytology-based screening options, combined VIA with conventional cytology testing was predicted to be the most attractive option. Multi-way sensitivity analyses did not change the results. Compared to rapid HPV DNA testing, VIA had a probability of cost-effectiveness of 73%. Compared to the vaccination only option, the probability that a program consisting of screening women every five years would be cost-effective was around 60% and 80% if the willingness-to-pay threshold is fixed at one and three GDP per capita, respectively. A VIA screening program in addition to a girl vaccination program was predicted to be the most attractive option in the health care context of Lao PDR. When compared with other screening methods, VIA was the primary recommended method for combination with vaccination in Lao PDR.
Predicting Positive Education Outcomes for Emerging Adults in Mental Health Systems of Care.
Brennan, Eileen M; Nygren, Peggy; Stephens, Robert L; Croskey, Adrienne
2016-10-01
Emerging adults who receive services based on positive youth development models have shown an ability to shape their own life course to achieve positive goals. This paper reports secondary data analysis from the Longitudinal Child and Family Outcome Study including 248 culturally diverse youth ages 17 through 22 receiving mental health services in systems of care. After 12 months of services, school performance was positively related to youth ratings of school functioning and service participation and satisfaction. Regression analysis revealed ratings of young peoples' perceptions of school functioning, and their experience in services added to the significant prediction of satisfactory school performance, even controlling for sex and attendance. Finally, in addition to expected predictors, participation in planning their own services significantly predicted enrollment in higher education for those who finished high school. Findings suggest that programs and practices based on positive youth development approaches can improve educational outcomes for emerging adults.
NASA Technical Reports Server (NTRS)
Lowell, C. E.; Deadmore, D. J.; Santoro, G. J.; Kohl, F. J.
1981-01-01
The effects of trace metal impurities in coal-derived liquids on deposition, high temperature corrosion and fouling were examined. Alloys were burner rig tested from 800 to 1100 C and corrosion was evaluated as a function of potential impurities. Actual and doped fuel test were used to define an empirical life prediction equation. An evaluation of inhibitors to reduce or eliminate accelerated corrosion was made. Barium and strontium were found to limit attack. Intermittent application of the inhibitors or silicon additions were found to be effective techniques for controlling deposition without losing the inhibitor benefits. A computer program was used to predict the dew points and compositions of deposits. These predictions were confirmed in deposition test. The potential for such deposits to plug cooling holes of turbine airfoils was evaluated. Tests indicated that, while a potential problem exists, it strongly depended on minor impurity variations.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-01
... DEPARTMENT OF VETERANS AFFAIRS 38 CFR Part 9 RIN 2900-AO20 Servicemembers' Group Life Insurance... regulations governing the Servicemembers' Group Life Insurance Traumatic Injury Protection (TSGLI) program by... expanded the Servicemembers' Group Life Insurance Traumatic Injury Protection (TSGLI) program to add...
Fatigue Life Methodology for Bonded Composite Skin/Stringer Configurations
NASA Technical Reports Server (NTRS)
Krueger, Ronald; Paris, Isabelle L.; OBrien, T. Kevin; Minguet, Pierre J.
2001-01-01
A methodology is presented for determining the fatigue life of composite structures based on fatigue characterization data and geometric nonlinear finite element (FE) analyses. To demonstrate the approach, predicted results were compared to fatigue tests performed on specimens which represented a tapered composite flange bonded onto a composite skin. In a first step, tension tests were performed to evaluate the debonding mechanisms between the flange and the skin. In a second step, a 2D FE model was developed to analyze the tests. To predict matrix cracking onset, the relationship between the tension load and the maximum principal stresses transverse to the fiber direction was determined through FE analysis. Transverse tension fatigue life data were used to -enerate an onset fatigue life P-N curve for matrix cracking. The resulting prediction was in good agreement with data from the fatigue tests. In a third step, a fracture mechanics approach based on FE analysis was used to determine the relationship between the tension load and the critical energy release rate. Mixed mode energy release rate fatigue life data were used to create a fatigue life onset G-N curve for delamination. The resulting prediction was in good agreement with data from the fatigue tests. Further, the prediction curve for cumulative life to failure was generated from the previous onset fatigue life curves. The results showed that the methodology offers a significant potential to Predict cumulative fatigue life of composite structures.
Predictive and Incremental Validity of Global and Domain-Based Adolescent Life Satisfaction Reports
ERIC Educational Resources Information Center
Haranin, Emily C.; Huebner, E. Scott; Suldo, Shannon M.
2007-01-01
Concurrent, predictive, and incremental validity of global and domain-based adolescent life satisfaction reports are examined with respect to internalizing and externalizing behavior problems. The Students' Life Satisfaction Scale (SLSS), Multidimensional Students' Life Satisfaction Scale (MSLSS), and measures of internalizing and externalizing…
ERIC Educational Resources Information Center
Tabourne, Carla E. S.
1995-01-01
Examined the effects on veteran and novice participants of a life review program for nursing home residents with Alzheimers disease or severe cognitive dysfunction. Results confirm the impact of the Life Review Program on level of disorientation, social interaction, and life review. Evidence suggests that life improvements may be stored in memory…
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.
Rossi, Ana P; Burris, Debra D; Lucas, F Leslie; Crocker, Gail A; Wasserman, James C
2014-12-05
Patients with CKD have a high prevalence of cardiovascular disease associated with or exacerbated by inactivity. This randomized, controlled study investigated whether a renal rehabilitation exercise program for patients with stages 3 or 4 CKD would improve their physical function and quality of life. In total, 119 adults with CKD stages 3 and 4 were randomized, and 107 of these patients proceeded to usual care or the renal rehabilitation exercise intervention consisting of usual care plus guided exercise two times per week for 12 weeks (24 sessions). Physical function was determined by three well established performance-based tests: 6-minute walk test, sit-to-stand test, and gait-speed test. Health-related quality of life was assessed by the RAND 36-Item Short Form Health Survey. At baseline, no differences in self-reported level of activity, 6-minute walk test, and sit-to-stand test scores were observed between the usual care (n=48) and renal rehabilitation exercise (n=59) groups, although baseline gait-speed test score was higher in the renal rehabilitation exercise group (P<0.001). At follow-up, the renal rehabilitation exercise group but not the usual care group showed significant improvements in the 6-minute walk test (+210.4±266.0 ft [19% improvement] versus -10±219.9 ft; P<0.001), the sit-to-stand test (+26.9±27% of age prediction [29% improvement] versus +0.7±12.1% of age prediction; P<0.001), and the RAND-36 physical measures of role functioning (P<0.01), physical functioning (P<0.01), energy/fatigue levels (P=0.01), and general health (P=0.03) and mental measure of pain scale (P=0.04). The renal rehabilitation exercise regimen was generally well tolerated. A 12-week/24-session renal rehabilitation exercise program improved physical capacity and quality of life in patients with CKD stages 3 and 4. Longer follow-up is needed to determine if these findings will translate into decreased mortality rates. Copyright © 2014 by the American Society of Nephrology.
32 CFR Appendix B to Part 50 - Overseas Life Insurance Registration Program
Code of Federal Regulations, 2010 CFR
2010-07-01
... 32 National Defense 1 2010-07-01 2010-07-01 false Overseas Life Insurance Registration Program B... Part 50—Overseas Life Insurance Registration Program A. Registration Criteria 1. Initial Registration a. Insurers must demonstrate continuous successful operation in the life insurance business for a period of...
32 CFR Appendix B to Part 50 - Overseas Life Insurance Registration Program
Code of Federal Regulations, 2011 CFR
2011-07-01
... 32 National Defense 1 2011-07-01 2011-07-01 false Overseas Life Insurance Registration Program B... Part 50—Overseas Life Insurance Registration Program A. Registration Criteria 1. Initial Registration a. Insurers must demonstrate continuous successful operation in the life insurance business for a period of...
Figueredo, Aurelio José; Ellis, Bruce J.
2010-01-01
The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many life history traits (e.g., health, relationship stability, economic success), (2) both environmental harshness and unpredictability would account for unique variance in expression of adolescent and young adult life history strategies, and (3) adolescent life history traits would predict young adult life history strategy. These predictions were supported. The current findings suggest that the environmental parameters of harshness and unpredictability have concurrent effects on life history development in adolescence, as well as longitudinal effects into young adulthood. In addition, life history traits appear to be stable across developmental time from adolescence into young adulthood. PMID:20634914
Survey report; health needs of the 21st century.
Raymond, S U
1989-01-01
Sustainability of development assistance programs depends greatly on the perceptions of priorities by recipient countries. A written survey was sent by the Catholic University of America's Institute for International Health and Development to 66 ministers of health in low-income and middle-income countries to assess their views of priority problems in health sector development. Response rate was 33%, coming from countries with highly diverse gross national products (GNPs), growth rates, mortality rates and life expectancies. Nevertheless, there was widespread agreement about priorities: 1) meeting costs of health care; 2) improving health care management and administration; and 3) extending communicable disease control. Communicable disease control and child health programs were more important to low-income countries than to middle-income countries. Costs, management and administration and the control of noncommunicable diseases were predicted to increase in importance. In demographics, urbanization, overall population growth and shift of workers from agriculture to industry and services were seen as the major problems of the past, and urbanization and the aging of populations accompanied by increasing life expectancies the major challenges of the future. Highest predicted training needs were for system managers and paramedical personnel. Government budgets, user fees and donor agencies were seen as the most important sources of past funding, with social security systems and fee-based payments increasing in importance in the future. The role of donor agencies would increase as would the need for more responsiveness. Future uncertainties include national economic growth, environmental problems, issues in ethics and changes in disease and technology.
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.
An Overview: NASA LeRC Structures Programs
NASA Technical Reports Server (NTRS)
Zaretsky, Erwin V.
1998-01-01
A workshop on National Structures Programs was held, jointly sponsored by the AIAA Structures Technical Committee, the University of Virginia's Center for Advanced Computational Technology and NASA. The Objectives of the Workshop were to: provide a forum for discussion of current Government-sponsored programs in the structures area; identify high potential research areas for future aerospace systems; and initiate suitable interaction mechanisms with the managers of structures programs. The presentations covered structures programs at NASA, DOD (AFOSR, ONR, ARO and DARPA), and DOE. This publication is the presentation of the Structures and Acoustics Division of the NASA Lewis Research Center. The Structures and Acoustics Division has its genesis dating back to 1943. It is responsible for NASA research related to rotating structures and structural hot sections of both airbreathing and rocket engines. The work of the division encompasses but is not limited to aeroelasticity, structural life prediction and reliability, fatigue and fracture, mechanical components such as bearings, gears, and seals, and aeroacoustics. These programs are discussed and the names of responsible individuals are provided for future reference.
Sensory education program development, application and its therapeutic effect in children
Chung, Hae-Kyung
2014-01-01
There has recently been Increased interest in the emotional intelligence (EQ) of elementary school students, which is recognized as a more important value than IQ (intelligence quotient) for predict of their success in school or later life. However, there are few sensory education programs, available to improve the EQ of elementary school student's in Korea. This study was conducted to develop an educational program that reflects the characteristics and contents of traditional rice culture and verify the effects of those programs on the EQ of children. The program was developed based on the ADDIE (Analysis, Design, Development, Implementation and Evaluation) model and participants were elementary school students in 3rd and 4th grade (n = 120) in Cheonan, Korea. Descriptive statistics and paired t-tests were used. EQ scores pertaining to the basic sense group, culture group, and food group were significantly improved after the sensory educational program(P < 0.05), but no change was observed in the control group. These findings indicate that sensory education contributed to improving elementary school children's Emotional Intelligence (EI) and their actual understanding about Korean traditional rice culture. PMID:24611113
Horrocks, Nicholas P C; Hegemann, Arne; Ostrowski, Stéphane; Ndithia, Henry; Shobrak, Mohammed; Williams, Joseph B; Matson, Kevin D; Tieleman, B I
2015-01-01
Investment in immune defences is predicted to covary with a variety of ecologically and evolutionarily relevant axes, with pace of life and environmental antigen exposure being two examples. These axes may themselves covary directly or inversely, and such relationships can lead to conflicting predictions regarding immune investment. If pace of life shapes immune investment then, following life history theory, slow-living, arid zone and tropical species should invest more in immunity than fast-living temperate species. Alternatively, if antigen exposure drives immune investment, then species in antigen-rich tropical and temperate environments are predicted to exhibit higher immune indices than species from antigen-poor arid locations. To test these contrasting predictions we investigated how variation in pace of life and antigen exposure influence immune investment in related lark species (Alaudidae) with differing life histories and predicted risks of exposure to environmental microbes and parasites. We used clutch size and total number of eggs laid per year as indicators of pace of life, and aridity, and the climatic variables that influence aridity, as correlates of antigen abundance. We quantified immune investment by measuring four indices of innate immunity. Pace of life explained little of the variation in immune investment, and only one immune measure correlated significantly with pace of life, but not in the predicted direction. Conversely, aridity, our proxy for environmental antigen exposure, was predictive of immune investment, and larks in more mesic environments had higher immune indices than those living in arid, low-risk locations. Our study suggests that abiotic environmental variables with strong ties to environmental antigen exposure can be important correlates of immunological variation.
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.
A comparison of fatigue life prediction methodologies for rotorcraft
NASA Technical Reports Server (NTRS)
Everett, R. A., Jr.
1990-01-01
Because of the current U.S. Army requirement that all new rotorcraft be designed to a 'six nines' reliability on fatigue life, this study was undertaken to assess the accuracy of the current safe life philosophy using the nominal stress Palmgrem-Miner linear cumulative damage rule to predict the fatigue life of rotorcraft dynamic components. It has been shown that this methodology can predict fatigue lives that differ from test lives by more than two orders of magnitude. A further objective of this work was to compare the accuracy of this methodology to another safe life method called the local strain approach as well as to a method which predicts fatigue life based solely on crack growth data. Spectrum fatigue tests were run on notched (k(sub t) = 3.2) specimens made of 4340 steel using the Felix/28 tests fairly well, being slightly on the unconservative side of the test data. The crack growth method, which is based on 'small crack' crack growth data and a crack-closure model, also predicted the fatigue lives very well with the predicted lives being slightly longer that the mean test lives but within the experimental scatter band. The crack growth model was also able to predict the change in test lives produced by the rainflow reconstructed spectra.
Argonne National Laboratory Li-alloy/FeS cell testing and R and D programs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gay, E.C.
1982-01-01
Groups of 12 or more identical Li-alloy/FeS cells fabricated by Eagle-Picher Industries, Inc. and Gould Inc. were operated at Argonne National Laboratory (ANL) in the status cell test program to obtain data for statistical analysis of cell cycle life and failure modes. The cells were full-size electric vehicle battery cells (150 to 350 Ah capacity) and they were cycled at the 4-h discharge rate and 8-h charge rate. The end of life was defined as a 20% loss of capacity or a decrease in the coulombic efficiency to less than 95%. Seventy-four cells (six groups of identical cells) were cycle-lifemore » tested and the results were analyzed statistically. The ultimate goal of this analysis was to predict cell and battery reliability. Testing of groups of identical cells also provided a means of identifying common failure modes which were eliminated by cell design changes. Mean time to failure (MTTF) for the cells based on the Weibull distribution is presented.« less
[Life style: instrument in health promotion programs].
Jiménez, D
1993-05-01
Non communicable diseases are increasing in third world countries, including Chile. Life style is one of the principal factors influencing this increase. Therefore programs and health strategies to modify the population life styles are needed. The programs developed to change life styles depend on the medical sociocultural scenery and the concept becomes outstanding when disease prevention is replaced by health promotion. The requirements for the application of the concept of life style in health promotion plans and fostering of healthy life styles are: 1) Training in behavioral epidemiology. 2) Election of a biopsychosocial concept of life style. 3) Identify the predominant scenery and target population. 4) Choose the appropriate educational methodologies to change behaviors. 5) Formalize strategies according to the boundaries where the program is applied. 6) Specify the qualifying requisites of the change agents, health promoters and program operators.
Early life nutritional programming of health and disease in The Gambia.
Moore, S E
2016-04-01
Exposures during the early life (periconceptional, prenatal and early postnatal) period are increasingly recognized as playing an important role in the aetiology of chronic non-communicable diseases (NCD), including coronary heart disease, stroke, hypertension, Type 2 diabetes and osteoporosis. The 'Developmental Origins of Health and Disease' (DOHaD) hypothesis states that these disorders originate through unbalanced nutrition early in life and risk is highest when there is a 'mismatch' between the early- and later-life environments. Thus, the DOHaD hypothesis would predict highest risk in countries where an excess of infants are born with low birth weight and where there is a rapid transition to nutritional adequacy or excess in adulthood. Here, I will review data from work conducted in rural Gambia, West Africa. Using demographic data dating back to the 1940s, the follow-up of randomized controlled trials of nutritional supplementation in pregnancy and the 'experiment of nature' that seasonality in this region provides, we have investigated the DOHaD hypothesis in a population with high rates of maternal and infant under-nutrition, a high burden from infectious disease, and an emerging risk of NCDs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jadaan, O.M.; Powers, L.M.; Nemeth, N.N.
1995-08-01
A probabilistic design methodology which predicts the fast fracture and time-dependent failure behavior of thermomechanically loaded ceramic components is discussed using the CARES/LIFE integrated design computer program. Slow crack growth (SCG) is assumed to be the mechanism responsible for delayed failure behavior. Inert strength and dynamic fatigue data obtained from testing coupon specimens (O-ring and C-ring specimens) are initially used to calculate the fast fracture and SCG material parameters as a function of temperature using the parameter estimation techniques available with the CARES/LIFE code. Finite element analysis (FEA) is used to compute the stress distributions for the tube as amore » function of applied pressure. Knowing the stress and temperature distributions and the fast fracture and SCG material parameters, the life time for a given tube can be computed. A stress-failure probability-time to failure (SPT) diagram is subsequently constructed for these tubes. Such a diagram can be used by design engineers to estimate the time to failure at a given failure probability level for a component subjected to a given thermomechanical load.« less
Ceramic Technology Project semiannual progress report, April 1992--September 1992
DOE Office of Scientific and Technical Information (OSTI.GOV)
Johnson, D.R.
1993-07-01
This project was developed to meet the ceramic technology requirements of the DOE Office of Transportation Systems` automotive technology programs. Significant progress in fabricating ceramic components for DOE, NASA, and DOE advanced heat engine programs show that operation of ceramic parts in high-temperature engines is feasible; however, addition research is needed in materials and processing, design, and data base and life prediction before industry will have a sufficient technology base for producing reliable cost-effective ceramic engine components commercially. A 5-yr project plan was developed, with focus on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments,more » and ceramic coatings for thermal barrier and wear applications in these engines.« less
Predicting life satisfaction of the Angolan elderly: a structural model.
Gutiérrez, M; Tomás, J M; Galiana, L; Sancho, P; Cebrià, M A
2013-01-01
Satisfaction with life is of particular interest in the study of old age well-being because it has arisen as an important component of old age. A considerable amount of research has been done to explain life satisfaction in the elderly, and there is growing empirical evidence on best predictors of life satisfaction. This research evaluates the predictive power of some aging process variables, on Angolan elderly people's life satisfaction, while including perceived health into the model. Data for this research come from a cross-sectional survey of elderly people living in the capital of Angola, Luanda. A total of 1003 Angolan elderly were surveyed on socio-demographic information, perceived health, active engagement, generativity, and life satisfaction. A Multiple Indicators Multiple Causes model was built to test variables' predictive power on life satisfaction. The estimated theoretical model fitted the data well. The main predictors were those related to active engagement with others. Perceived health also had a significant and positive effect on life satisfaction. Several processes together may predict life satisfaction in the elderly population of Angola, and the variance accounted for it is large enough to be considered relevant. The key factor associated to life satisfaction seems to be active engagement with others.
Safe Life Propulsion Design Technologies (3rd Generation Propulsion Research and Technology)
NASA Technical Reports Server (NTRS)
Ellis, Rod
2000-01-01
The tasks outlined in this viewgraph presentation on safe life propulsion design technologies (third generation propulsion research and technology) include the following: (1) Ceramic matrix composite (CMC) life prediction methods; (2) Life prediction methods for ultra high temperature polymer matrix composites for reusable launch vehicle (RLV) airframe and engine application; (3) Enabling design and life prediction technology for cost effective large-scale utilization of MMCs and innovative metallic material concepts; (4) Probabilistic analysis methods for brittle materials and structures; (5) Damage assessment in CMC propulsion components using nondestructive characterization techniques; and (6) High temperature structural seals for RLV applications.
Glass Fibre/Epoxy Resin Interface Life-Time Prediction.
1983-04-01
RD-Ai32 26 GLASS FIBRE /POXY RESIN INTERFACE LIFE-TIME PREDICTION 1/1 (U) BRISTOL UNIV (ENGLAND) H H WILLS PHYSICS LAB K H RSHBEE ET AL. APR 83...D 3005-MS GLASS FIBRE /EPOXY RESIN INTERFACE LIFE-TIME PREDICTION - Final Report by K H G Ashbee, Principal Investigator R Ho~l J P Sargent Elizabeth...REPORT h PERIOD COVERED. Glass Fibre /Epoxy Resin Interface Life-time F-inal Technical 11’ port PreictonApril 1981 - A:’ril 1983 6. PERFORMING ORG. REPORT
Purpose, Mood, and Pleasure in Predicting Satisfaction Judgments
ERIC Educational Resources Information Center
Diener, Ed; Fujita, Frank; Tay, Louis; Biswas-Diener, Robert
2012-01-01
We examined the extent to which satisfaction with life, with one's self, and with one's day are predicted by pleasure, purpose in life, interest, and mood. In a sample of 222 college students we found that both satisfaction with life and self-esteem were best predicted by positive feelings and an absence of negative feelings, as well as purpose in…
Strier, Karen B; Possamai, Carla B; Tabacow, Fernanda P; Pissinatti, Alcides; Lanna, Andre M; Rodrigues de Melo, Fabiano; Moreira, Leandro; Talebi, Maurício; Breves, Paula; Mendes, Sérgio L; Jerusalinsky, Leandro
2017-01-01
Demographic data are essential to assessments of the status of endangered species. However, establishing an integrated monitoring program to obtain useful data on contemporary and future population trends requires both the identification of priority areas and populations and realistic evaluations of the kinds of data that can be obtained under different monitoring regimes. We analyzed all known populations of a critically endangered primate, the muriqui (genus: Brachyteles) using population size, genetic uniqueness, geographic importance (including potential importance in corridor programs) and implementability scores to define monitoring priorities. Our analyses revealed nine priority populations for the northern muriqui (B. hypoxanthus) and nine for the southern muriqui (B. arachnoides). In addition, we employed knowledge of muriqui developmental and life history characteristics to define the minimum monitoring intensity needed to evaluate demographic trends along a continuum ranging from simple descriptive changes in population size to predictions of population changes derived from individual based life histories. Our study, stimulated by the Brazilian government's National Action Plan for the Conservation of Muriquis, is fundamental to meeting the conservation goals for this genus, and also provides a model for defining priorities and methods for the implementation of integrated demographic monitoring programs for other endangered and critically endangered species of primates.
Life prediction of coated and uncoated metallic interconnect for solid oxide fuel cell applications
NASA Astrophysics Data System (ADS)
Liu, W. N.; Sun, X.; Stephens, E.; Khaleel, M. A.
In this paper, we present an integrated experimental and modeling methodology in predicting the life of coated and uncoated metallic interconnect (IC) for solid oxide fuel cell (SOFC) applications. The ultimate goal is to provide cell designer and manufacture with a predictive methodology such that the life of the IC system can be managed and optimized through different coating thickness to meet the overall cell designed life. Crofer 22 APU is used as the example IC material system. The life of coated and uncoated Crofer 22 APU under isothermal cooling was predicted by comparing the predicted interfacial strength and the interfacial stresses induced by the cooling process from the operating temperature to room temperature, together with the measured oxide scale growth kinetics. It was found that the interfacial strength between the oxide scale and the Crofer 22 APU substrate decreases with the growth of the oxide scale, and that the interfacial strength for the oxide scale/spinel coating interface is much higher than that of the oxide scale/Crofer 22 APU substrate interface. As expected, the predicted life of the coated Crofer 22 APU is significantly longer than that of the uncoated Crofer 22 APU.
Life sciences flight experiments program - Overview
NASA Technical Reports Server (NTRS)
Berry, W. E.; Dant, C. C.
1981-01-01
The considered LSFE program focuses on Spacelab life sciences missions planned for the 1984-1985 time frame. Life Sciences Spacelab payloads, launched at approximately 18-months intervals, will enable scientists to test hypotheses from such disciplines as vestibular physiology, developmental biology, biochemistry, cell biology, plant physiology, and a variety of other life sciences. An overview is presented of the LSFE program that will take advantage of the unique opportunities for biological experimentation possible on Spacelab. Program structure, schedules, and status are considered along with questions of program selection, and the science investigator working groups. A description is presented of the life sciences laboratory equipment program, taking into account the general purpose work station, the research animal holding facility, and the plant growth unit.
Factors associated with the completion of falls prevention program.
Batra, Anamica; Page, Timothy; Melchior, Michael; Seff, Laura; Vieira, Edgar Ramos; Palmer, Richard C
2013-12-01
Falls and fear of falling can affect independence and quality of life of older adults. Falls prevention programs may help avoiding these issues if completed. Understanding factors that are associated with completion of falls prevention programs is important. To reduce fear of falling and increase activity levels, a Matter of Balance (MOB) and un Asunto de Equilibrio (ADE) workshops were offered to 3420 older adults in South Florida between 1 October 2008 and 31 December 2011. Workshops were conducted in English or Spanish over eight, 2-hour sessions. Participants completed a demographic and a pre-post questionnaire. Factors associated with program completion were identified using logistic regression. For MOB, females were more likely to complete the program (OR = 2.076, P = 0.02). For ADE, females, moderate and extreme interference by falls in social activities were found to affect completion (OR = 2.116, P = 0.001; OR = 2.269, P = 0.003 and OR = 4.133, P = 0.008, respectively). Different factors predicted completion of both programs. Awareness of these factors can help lower the attrition rates, increase benefits and cost effectiveness of program. Future research needs to explore why certain groups had a higher likelihood of completing either program.
Developmental Origins of Chronic Kidney Disease: Should We Focus on Early Life?
Tain, You-Lin; Hsu, Chien-Ning
2017-01-01
Chronic kidney disease (CKD) is becoming a global burden, despite recent advances in management. CKD can begin in early life by so-called “developmental programming” or “developmental origins of health and disease” (DOHaD). Early-life insults cause structural and functional changes in the developing kidney, which is called renal programming. Epidemiological and experimental evidence supports the proposition that early-life adverse events lead to renal programming and make subjects vulnerable to developing CKD and its comorbidities in later life. In addition to low nephron endowment, several mechanisms have been proposed for renal programming. The DOHaD concept opens a new window to offset the programming process in early life to prevent the development of adult kidney disease, namely reprogramming. Here, we review the key themes on the developmental origins of CKD. We have particularly focused on the following areas: evidence from human studies support fetal programming of kidney disease; insight from animal models of renal programming; hypothetical mechanisms of renal programming; alterations of renal transcriptome in response to early-life insults; and the application of reprogramming interventions to prevent the programming of kidney disease. PMID:28208659
Defense Threat Reduction Agency > Careers > Onboarding > Before You Report
Development Work/Life Programs Onboarding Onboarding Overview Before You Report Sponsor Program Getting Here , you may be eligible to enroll in health, dental and vision, life insurance, and flexible spending and Mass Transit Benefit Program. Health/Dental/Vision/Life for Civilian Employees Health/Dental/Life
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.
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.
The Delaware Department of Correction Life Skills Program. Program Focus.
ERIC Educational Resources Information Center
Finn, Peter
Since 1993, the Delaware Department of Correction has offered a Life Skills Program in its four state prisons. Each year, as many as 300 inmates (of the 5,000 housed inmates) enroll in the program, and nearly 85 percent of them graduate. The 4-month program has three major components: academics, violence reduction, and applied life skills. The…
Evaluation of sexual function, quality of life, and mental and physical health in pregnant women.
Nik-Azin, Amir; Nainian, Mohammad Reza; Zamani, Mahnaz; Bavojdan, Marjan Rabani; Bavojdan, Mozhgan Rabani; Motlagh, Marjan Jamali
2013-12-01
To evaluate sexual function and its relationship with quality of life, and mental and physical health in pregnant women. Obtained results showed that 59 (39/3%) pregnant women were "very dissatisfied", 25 (16/7%) women were "moderately dissatisfied", 64 (42/7%) women were "both satisfied and unsatisfied", only 2 (1/3%) women were relatively satisfied, and no one was "very satisfied". There is a significantly negative weak correlation between female sexual function with anxiety and depression, while there is a significantly positive weak correlation between female sexual function with the general quality of life, psychological health and environment dimensions. Only depression predicts female sexual function significantly. The women more than 10 years passed of their marriage showed more sexual satisfaction compared to those less than 10 years passed of their marriage (p< 0.05). The roles of predictive variables in sexual dissatisfaction, as well as the limitations for the study are discussed in the article. Obtained results showed that 59 (39/3%) pregnant women were "very dissatisfied", 25 (16/7%) women were "moderately dissatisfied", 64 (42/7%) women were "both satisfied and unsatisfied", only 2 (1/3%) women were relatively satisfied, and no one was "very satisfied". There is a significantly negative weak correlation between female sexual function with anxiety and depression, while there is a significantly positive weak correlation between female sexual function with the general quality of life, psychological health and environment dimensions. Only depression predicts female sexual function significantly. The women more than 10 years passed of their marriage showed more sexual satisfaction compared to those less than 10 years passed of their marriage (p< 0.05). The roles of predictive variables in sexual dissatisfaction, as well as the limitations for the study are discussed in the article. Depression as same as environment heath had an important effect on sexual satisfaction in pregnant women and so assessment of depression and environment health in medical program for pregnant women is necessary. Also considering decrease in sexual satisfaction in aging training new methods for sexuality can be useful.
Adeniyi, D A; Wei, Z; Yang, Y
2018-01-30
A wealth of data are available within the health care system, however, effective analysis tools for exploring the hidden patterns in these datasets are lacking. To alleviate this limitation, this paper proposes a simple but promising hybrid predictive model by suitably combining the Chi-square distance measurement with case-based reasoning technique. The study presents the realization of an automated risk calculator and death prediction in some life-threatening ailments using Chi-square case-based reasoning (χ 2 CBR) model. The proposed predictive engine is capable of reducing runtime and speeds up execution process through the use of critical χ 2 distribution value. This work also showcases the development of a novel feature selection method referred to as frequent item based rule (FIBR) method. This FIBR method is used for selecting the best feature for the proposed χ 2 CBR model at the preprocessing stage of the predictive procedures. The implementation of the proposed risk calculator is achieved through the use of an in-house developed PHP program experimented with XAMP/Apache HTTP server as hosting server. The process of data acquisition and case-based development is implemented using the MySQL application. Performance comparison between our system, the NBY, the ED-KNN, the ANN, the SVM, the Random Forest and the traditional CBR techniques shows that the quality of predictions produced by our system outperformed the baseline methods studied. The result of our experiment shows that the precision rate and predictive quality of our system in most cases are equal to or greater than 70%. Our result also shows that the proposed system executes faster than the baseline methods studied. Therefore, the proposed risk calculator is capable of providing useful, consistent, faster, accurate and efficient risk level prediction to both the patients and the physicians at any time, online and on a real-time basis.
Zeitler, Emily P.; Al-Khatib, Sana M.; Drozda, Joseph P.; Kessler, Larry G.; Kirtane, Ajay J.; Kong, David F.; Laschinger, John; Marinac-Dabic, Danica; Morice, Marie-Claude; Reed, Terrie; Sedrakyan, Art; Stein, Kenneth M.; Tcheng, James; Krucoff, Mitchell W.
2015-01-01
The Medical Device Epidemiological Network Initiative (MDEpiNet) is a public-private partnership between the US Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) and participating partners. The Predictable and SuStainable Implementation of National Cardiovascular Registries (PASSION) program is an MDEpiNet-sponsored program which aims to demonstrate the goals of MDEpiNet by using cardiovascular medical device registries to bridge evidence gaps across the medical device total product life cycle (TPLC). To this end, a PASSION Think Tank meeting took place in October 2014 in Silver Spring, MD, to facilitate discussion between stakeholders about the successes, challenges, and future novel applications of medical device registries, with particular emphasis on identifying pilot projects. Participants spanned a broad range of groups including patients, device manufacturers, regulators, physicians/academicians, professional societies, providers, and payers. The meeting focus included four areas of cardiovascular medicine intended to cultivate interest in four MDEpiNet Disease Specific/Device Specific Working Groups: coronary intervention, electrophysiology, valvular disease, and peripheral vascular disease. In addition, more general issues applying to registry-based infrastructure and analytical methodologies for assessing device benefit/risk were considered to provide context for the Working Groups as PASSION programs going forward. This article summarizes the discussions at the meeting and the future directions of the PASSION program. PMID:26699602
Levin, Michael E; Hayes, Steven C; Pistorello, Jacqueline; Seeley, John R
2016-03-01
This study sought to test the feasibility of a web-based Acceptance and Commitment Training (ACT) prototype prevention program called ACT on College Life (ACT-CL). A sample of 234 university students was randomized to either the ACT-CL website or a mental health education (MHE) website. Findings indicated a lower level of user engagement and satisfaction ratings with the prototype of ACT-CL than the MHE website. There were no significant differences between conditions on outcome measures at post or follow-up. However, statistical trends suggested the MHE condition actually led to greater remission of severe symptoms than the ACT-CL condition among those with severe symptoms at baseline. There were no differences between conditions on ACT process of change measures. Changes in psychological flexibility were predictive of changes in mental health across conditions, but relations dissipated over time. Furthermore, greater engagement in some components of ACT-CL predicted improvements in psychological flexibility, though not on mental health outcomes. The effects of the ACT-CL program on mental health outcomes and ACT process measures were largely equivalent to those of an education website, although there was a lower level of program engagement with ACT-CL. Findings are discussed in the context of feasibility issues and lessons learned for program revisions. © 2016 Wiley Periodicals, Inc.
The Cost-Effectiveness of High-Risk Lung Cancer Screening and Drivers of Program Efficiency.
Cressman, Sonya; Peacock, Stuart J; Tammemägi, Martin C; Evans, William K; Leighl, Natasha B; Goffin, John R; Tremblay, Alain; Liu, Geoffrey; Manos, Daria; MacEachern, Paul; Bhatia, Rick; Puksa, Serge; Nicholas, Garth; McWilliams, Annette; Mayo, John R; Yee, John; English, John C; Pataky, Reka; McPherson, Emily; Atkar-Khattra, Sukhinder; Johnston, Michael R; Schmidt, Heidi; Shepherd, Frances A; Soghrati, Kam; Amjadi, Kayvan; Burrowes, Paul; Couture, Christian; Sekhon, Harmanjatinder S; Yasufuku, Kazuhiro; Goss, Glenwood; Ionescu, Diana N; Hwang, David M; Martel, Simon; Sin, Don D; Tan, Wan C; Urbanski, Stefan; Xu, Zhaolin; Tsao, Ming-Sound; Lam, Stephen
2017-08-01
Lung cancer risk prediction models have the potential to make programs more affordable; however, the economic evidence is limited. Participants in the National Lung Cancer Screening Trial (NLST) were retrospectively identified with the risk prediction tool developed from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. The high-risk subgroup was assessed for lung cancer incidence and demographic characteristics compared with those in the low-risk subgroup and the Pan-Canadian Early Detection of Lung Cancer Study (PanCan), which is an observational study that was high-risk-selected in Canada. A comparison of high-risk screening versus standard care was made with a decision-analytic model using data from the NLST with Canadian cost data from screening and treatment in the PanCan study. Probabilistic and deterministic sensitivity analyses were undertaken to assess uncertainty and identify drivers of program efficiency. Use of the risk prediction tool developed from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial with a threshold set at 2% over 6 years would have reduced the number of individuals who needed to be screened in the NLST by 81%. High-risk screening participants in the NLST had more adverse demographic characteristics than their counterparts in the PanCan study. High-risk screening would cost $20,724 (in 2015 Canadian dollars) per quality-adjusted life-year gained and would be considered cost-effective at a willingness-to-pay threshold of $100,000 in Canadian dollars per quality-adjusted life-year gained with a probability of 0.62. Cost-effectiveness was driven primarily by non-lung cancer outcomes. Higher noncurative drug costs or current costs for immunotherapy and targeted therapies in the United States would render lung cancer screening a cost-saving intervention. Non-lung cancer outcomes drive screening efficiency in diverse, tobacco-exposed populations. Use of risk selection can reduce the budget impact, and screening may even offer cost savings if noncurative treatment costs continue to rise. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.
Life Cycle Costing as an Aid in Decision Making
ERIC Educational Resources Information Center
Blake, Robert
1973-01-01
Within an accepted process and measures framework, total program cost over the life of the program, including the life of facility(ies) that house the program, provides a rational decisionmaking environment for the accountable managers. (Author)
Fatigue life analysis of a turboprop reduction gearbox
NASA Technical Reports Server (NTRS)
Lewicki, D. G.; Black, J. D.; Savage, M.; Coy, J. J.
1985-01-01
A fatigue life analysis of the Allison T56/501 turboprop reduction gearbox was developed. The life and reliability of the gearbox was based on the lives and reliabilities of the main power train bearings and gears. The bearing and gear lives were determined using the Lundberg-Palmgren theory and a mission profile. The five planet bearing set had the shortest calculated life among the various gearbox components, which agreed with field experience where the planet bearing had the greatest incidences of failure. The analytical predictions of relative lives among the various bearings were in reasonable agreement with field experience. The predicted gearbox life was in excellent agreement with field data when the material life adjustment factors alone were used. The gearbox had a lower predicted life in comparison with field data when no life adjustment factors were used or when lubrication life adjustment factors were used either alone or in combination with the material factors.
Fatigue life analysis of a turboprop reduction gearbox
NASA Technical Reports Server (NTRS)
Lewicki, D. G.; Coy, J. J.; Black, J. D.; Savage, M.
1986-01-01
A fatigue life analysis of the Allison T56/501 turboprop reduction gearbox was developed. The life and reliability of the gearbox was based on the lives and reliabilities of the main power train bearings and gears. The bearing and gear lives were determined using the Lundberg-Palmgren theory and a mission profile. The five planet bearing set had the shortest calculated life among the various gearbox components, which agreed with field experience where the planet bearing had the greatest incidences of failure. The analytical predictions of relative lives among the various bearings were in reasonable agreement with field experience. The predicted gearbox life was in excellent agreement with field data when the material life adjustment factors alone were used. The gearbox had a lower predicted life in comparison with field data when no life adjustment factors were used or when lubrication life adjustment factors were used either alone or in combination with the material factors.
Bravo, Gina; Sene, Modou; Arcand, Marcel
2017-07-01
Family members are often called upon to make decisions for an incapacitated relative. Yet they have difficulty predicting a loved one's desire to receive treatments in hypothetical situations. We tested the hypothesis that this difficulty could in part be explained by discrepant quality-of-life assessments. The data come from 235 community-dwelling adults aged 70 years and over who rated their quality of life and desire for specified interventions in four health states (current state, mild to moderate stroke, incurable brain cancer, and severe dementia). All ratings were made on Likert-type scales. Using identical rating scales, a surrogate chosen by the older adult was asked to predict the latter's responses. Linear mixed models were fitted to determine whether differences in quality-of-life ratings between the older adult and surrogate were associated with surrogates' inaccuracy in predicting desire for treatment. The difference in quality-of-life ratings was a significant predictor of prediction inaccuracy for the three hypothetical health states (p < 0.01) and nearly significant for the current health state (p = 0.077). All regression coefficients were negative, implying that the more the surrogate overestimated quality of life compared to the older adult, the more he or she overestimated the older adult's desire to be treated. Discrepant quality-of-life ratings are associated with surrogates' difficulty in predicting desire for life-sustaining interventions in hypothetical situations. This finding underscores the importance of discussing anticipated quality of life in states of cognitive decline, to better prepare family members for making difficult decisions for their loved ones. ISRCTN89993391.
Personality trait changes among young Finns: the role of life events and transitions.
Leikas, Sointu; Salmela-Aro, Katariina
2015-02-01
Recent research has shown that personality traits continue to develop throughout the life span, but most profound changes are typically found during young adulthood. Increasing evidence suggests that life events play a significant role in many of these changes. The present longitudinal study examined the role of work, education, social, and health-related life events in the development of the Big Five traits among young Finns. Participants were originally recruited in 2004 through elementary schools in a middle-sized Finnish city. Participants' Big Five traits and life events were measured via self-reports at ages 20 and 23 (Ns = 597 and 588, respectively). Entering work life, beginning a relationship, and studying in university predicted increases in Conscientiousness, trying drugs predicted increases in Neuroticism, and onset of a chronic disease predicted increases in Neuroticism and Conscientiousness between ages 20 and 23. The results suggest that mature life transitions relate to stronger increases in Conscientiousness in young adulthood, and that non-normative life choices and events may predict increases in Neuroticism. © 2014 Wiley Periodicals, Inc.
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.
The Sun Health Research Institute Brain Donation Program: Description and Eexperience, 1987–2007
Sue, Lucia I.; Walker, Douglas G.; Roher, Alex E.; Lue, LihFen; Vedders, Linda; Connor, Donald J.; Sabbagh, Marwan N.; Rogers, Joseph
2008-01-01
The Brain Donation Program at Sun Health Research Institute has been in continual operation since 1987, with over 1000 brains banked. The population studied primarily resides in the retirement communities of northwest metropolitan Phoenix, Arizona. The Institute is affiliated with Sun Health, a nonprofit community-owned and operated health care provider. Subjects are enrolled prospectively to allow standardized clinical assessments during life. Funding comes primarily from competitive grants. The Program has made short postmortem brain retrieval a priority, with a 2.75-h median postmortem interval for the entire collection. This maximizes the utility of the resource for molecular studies; frozen tissue from approximately 82% of all cases is suitable for RNA studies. Studies performed in-house have shown that, even with very short postmortem intervals, increasing delays in brain retrieval adversely affect RNA integrity and that cerebrospinal fluid pH increases with postmortem interval but does not predict tissue viability. PMID:18347928
Finding the Perfect Match: Factors That Influence Family Medicine Residency Selection.
Wright, Katherine M; Ryan, Elizabeth R; Gatta, John L; Anderson, Lauren; Clements, Deborah S
2016-04-01
Residency program selection is a significant experience for emerging physicians, yet there is limited information about how applicants narrow their list of potential programs. This study examines factors that influence residency program selection among medical students interested in family medicine at the time of application. Medical students with an expressed interest in family medicine were invited to participate in a 37-item, online survey. Students were asked to rate factors that may impact residency selection on a 6-point Likert scale in addition to three open-ended qualitative questions. Mean values were calculated for each survey item and were used to determine a rank order for selection criteria. Logistic regression analysis was performed to identify factors that predict a strong interest in urban, suburban, and rural residency programs. Logistic regression was also used to identify factors that predict a strong interest in academic health center-based residencies, community-based residencies, and community-based residencies with an academic affiliation. A total of 705 medical students from 32 states across the country completed the survey. Location, work/life balance, and program structure (curriculum, schedule) were rated the most important factors for residency selection. Logistic regression analysis was used to refine our understanding of how each factor relates to specific types of residencies. These findings have implications for how to best advise students in selecting a residency, as well as marketing residencies to the right candidates. Refining the recruitment process will ensure a better fit between applicants and potential programs. Limited recruitment resources may be better utilized by focusing on targeted dissemination strategies.
Life assessment of structural components using inelastic finite element analyses
NASA Technical Reports Server (NTRS)
Arya, Vinod K.; Halford, Gary R.
1993-01-01
The need for enhanced and improved performance of structural components subject to severe cyclic thermal/mechanical loadings, such as in the aerospace industry, requires development of appropriate solution technologies involving time-dependent inelastic analyses. Such analyses are mandatory to predict local stress-strain response and to assess more accurately the cyclic life time of structural components. The NASA-Lewis Research Center is cognizant of this need. As a result of concerted efforts at Lewis during the last few years, several such finite element solution technologies (in conjunction with the finite element program MARC) were developed and successfully applied to numerous uniaxial and multiaxial problems. These solution technologies, although developed for use with MARC program, are general in nature and can easily be extended for adaptation with other finite element programs such as ABAQUS, ANSYS, etc. The description and results obtained from two such inelastic finite element solution technologies are presented. The first employs a classical (non-unified) creep-plasticity model. An application of this technology is presented for a hypersonic inlet cowl-lip problem. The second of these technologies uses a unified creep-plasticity model put forth by Freed. The structural component for which this finite element solution technology is illustrated, is a cylindrical rocket engine thrust chamber. The advantages of employing a viscoplastic model for nonlinear time-dependent structural analyses are demonstrated. The life analyses for cowl-lip and cylindrical thrust chambers are presented. These analyses are conducted by using the stress-strain response of these components obtained from the corresponding finite element analyses.
Lifeskills Program Evaluation at Mammoth Heights Elementary School
ERIC Educational Resources Information Center
Tanner, Emma Moss
2016-01-01
This study is a program evaluation of the Life Skills Program at Mammoth Heights Elementary in the Douglas County School District. The overall goal of the Life Skills Program is to increase students' independent and daily living skills through the teaching of communication, social-emotional skills and academic skills. Students in the Life Skills…
A life prediction methodology for encapsulated solar cells
NASA Technical Reports Server (NTRS)
Coulbert, C. D.
1978-01-01
This paper presents an approach to the development of a life prediction methodology for encapsulated solar cells which are intended to operate for twenty years or more in a terrestrial environment. Such a methodology, or solar cell life prediction model, requires the development of quantitative intermediate relationships between local environmental stress parameters and the basic chemical mechanisms of encapsulant aging leading to solar cell failures. The use of accelerated/abbreviated testing to develop these intermediate relationships and in revealing failure modes is discussed. Current field and demonstration tests of solar cell arrays and the present laboratory tests to qualify solar module designs provide very little data applicable to predicting the long-term performance of encapsulated solar cells. An approach to enhancing the value of such field tests to provide data for life prediction is described.
The Life Sciences program at the NASA Ames Research Center - An overview
NASA Technical Reports Server (NTRS)
Vernikos-Danellis, Joan; Sharp, Joseph C.
1989-01-01
The research projects planned for the Life Sciences program have a goal of answering basic questions concerning the nature of life itself and its evolution in the universe from basic elements, as well as the search for extraterrestrial intelligence. The program also includes studies of the evolution and development of life on the planet earth, and the global changes occurring today that affect life on the earth. The paper describes the simulation models developed to study the effects of space, the flight projects of the program, and the biomedical program, which currently focuses on the physiological changes in the human body that are associated with space flights and the interactions among these changes.
Effect of Roller Profile on Cylindrical Roller Bearing Life Prediction
NASA Technical Reports Server (NTRS)
Poplawski, Joseph V.; Zaretsky, Erwin V.; Peters, Steven M.
2000-01-01
Four roller profiles used in cylindrical roller bearing design and manufacture were analyzed using both a closed form solution and finite element analysis (FEA) for stress and life. The roller profiles analyzed were flat, tapered end, aerospace, and fully crowned loaded against a flat raceway. Four rolling-element bearing life models were chosen for this analysis and compared. These were those of Weibull, Lundberg and Palmgren, Ioannides and Harris, and Zaretsky. The flat roller profile without edge loading has the longest predicted life. However, edge loading can reduce life by as much as 98 percent. The end tapered profile produced the highest lives but not significantly different than the aerospace profile. The fully crowned profile produces the lowest lives. The resultant predicted life at each stress condition not only depends on the life equation used but also on the Weibull slope assumed. For Weibull slopes of 1.5 and 2, both Lundberg-Palmgren and Iaonnides-Harris equations predict lower lives than the ANSI/ABMAJISO standards. Based upon the Hertz stresses for line contact, the accepted load-life exponent of 10/3 results in a maximum Hertz stress-life exponent equal to 6.6. This value is inconsistent with that experienced in the field.
Phillips, Anna C; Carroll, Douglas; Der, Geoff
2015-01-01
Stressful life events are known to contribute to development of depression; however, it is possible this link is bidirectional. The present study examined whether such stress generation effects are greater than the effects of stressful life events on depression, and whether stress generation is also evident with anxiety. Participants were two large age cohorts (N = 732 aged 44 years; N = 705 aged 63 years) from the West of Scotland Twenty-07 study. Stressful life events, depression, and anxiety symptoms were measured twice five years apart. Cross-lagged panel analysis examined the mutual influences of stressful life events on depression and on anxiety over time. Life events predicted later depressive symptomatology (p = .01), but the depression predicting life events relationship was less strong (p = .06), whereas earlier anxiety predicted life events five years later (p = .001). There was evidence of sex differences in the extent to which life events predicted later anxiety. This study provides evidence of stress causation for depression and weaker evidence for stress generation. In contrast, there was strong evidence of stress generation for anxiety but weaker evidence for stress causation, and that differed for men and women.
Phillips, Anna C.; Carroll, Douglas; Der, Geoff
2016-01-01
Background and Objectives Stressful life events are known to contribute to development of depression, however, it is possible this link is bi-directional. The present study examined whether such stress generation effects are greater than the effects of stressful life events on depression, and whether stress generation is also evident with anxiety. Design Participants were two large age cohorts (N = 732 aged 44 years; N = 705 aged 63 years) from the West of Scotland Twenty-07 study. Methods Stressful life events, depression and anxiety symptoms were measured twice five years apart. Cross-lagged panel analysis examined the mutual influences of stressful life events on depression and on anxiety over time. Results Life events predicted later depressive symptomatology (p = .01), but the depression predicting life events relationship was less strong (p = .06), whereas earlier anxiety predicted life events five years later (p = .001). There was evidence of sex differences in the extent to which life events predicted later anxiety. Conclusions This study provides evidence of stress causation for depression and weaker evidence for stress generation. In contrast, there was strong evidence of stress generation for anxiety but weaker evidence for stress causation, and that differed for men and women. PMID:25572915
Fatigue life of high-speed ball bearings with silicon nitride balls
NASA Technical Reports Server (NTRS)
Parker, R. J.; Zaretsky, E. V.
1974-01-01
Hot-pressed silicon nitride was evaluated as a rolling-element bearing material. The five-ball fatigue tester was used to test 12.7-mm- diameter silicon nitride balls at maximum Hertz stresses ranging from 4.27 x 10 to the 9th power n/sq m to 6.21 x 10 to the 9th power n/sq m at a race temperature of 328K. The fatigue life of NC-132 hot-pressed silicon nitride was found to be equal to typical bearing steels and much greater than other ceramic or cermet materials at the same stress levels. A digital computer program was used to predict the fatigue life of 120-mm- bore angular-contact ball bearings containing either steel or silicon nitride balls. The analysis indicates that there is no improvement in the lives of bearings of the same geometry operating at DN values from 2 to 4 million where silicon nitride balls are used in place of steel balls.
Aging and Down syndrome: implications for physical therapy.
Barnhart, Robert C; Connolly, Barbara
2007-10-01
The number of people over the age of 60 years with lifelong developmental delays is predicted to double by 2030. Down syndrome (DS) is the most frequent chromosomal cause of developmental delays. As the life expectancy of people with DS increases, changes in body function and structure secondary to aging have the potential to lead to activity limitations and participation restrictions for this population. The purpose of this update is to: (1) provide an overview of the common body function and structure changes that occur in adults with DS as they age (thyroid dysfunction, cardiovascular disorders, obesity, musculoskeletal disorders, Alzheimer disease, depression) and (2) apply current research on exercise to the prevention of activity limitations and participation restrictions. As individuals with DS age, a shift in emphasis from disability prevention to the prevention of conditions that lead to activity and participation limitations must occur. Exercise programs appear to have potential to positively affect the overall health of adults with DS, thereby increasing the quality of life and years of healthy life for these individuals.
Spohr, Stephanie A; Taxman, Faye S; Walters, Scott T
2017-04-01
The criminal justice system tends to emphasize external contingencies (e.g., fees, jail time) to motivate offender compliance. However, people's reasons for desistance vary considerably. This study evaluated the acceptability, utility, and predictive validity of questions that ask about people's reasons for wanting to successfully complete probation. Substance-using probationers (N=113) participated in a web-based computer intervention that targeted substance use and treatment initiation. Questions around seven dimensions of reasons for completing probation were developed to provide tailored feedback during the web-based program. A principle components factor analysis found that survey items loaded onto two distinct factors. Factor one, "Tangible Loss" focused on external and present-focused reasons. Factor two, "Better Life" focused on internal and future-focused reasons. There was a significant negative association between Better Life scores and days of substance use after two months (β=-0.31, SE=0.13, p<0.05). There was a significant positive association with Better Life scores and days of treatment attendance (β=1.46, SE=0.26, p<0.001). Tangible Loss scores were no associated with substance use and treatment attendance. These findings may help to create more effective motivational tracks in e-health interventions, and may complement traditional motivation measures with an explicit focus on people's stated reasons for wanting to complete probation. Copyright © 2017 Elsevier Ltd. All rights reserved.
A creep cavity growth model for creep-fatigue life prediction of a unidirectional W/Cu composite
NASA Astrophysics Data System (ADS)
Kim, Young-Suk; Verrilli, Michael J.; Halford, Gary R.
1992-05-01
A microstructural model was developed to predict creep-fatigue life in a (0)(sub 4), 9 volume percent tungsten fiber-reinforced copper matrix composite at the temperature of 833 K. The mechanism of failure of the composite is assumed to be governed by the growth of quasi-equilibrium cavities in the copper matrix of the composite, based on the microscopically observed failure mechanisms. The methodology uses a cavity growth model developed for prediction of creep fracture. Instantaneous values of strain rate and stress in the copper matrix during fatigue cycles were calculated and incorporated in the model to predict cyclic life. The stress in the copper matrix was determined by use of a simple two-bar model for the fiber and matrix during cyclic loading. The model successfully predicted the composite creep-fatigue life under tension-tension cyclic loading through the use of this instantaneous matrix stress level. Inclusion of additional mechanisms such as cavity nucleation, grain boundary sliding, and the effect of fibers on matrix-stress level would result in more generalized predictions of creep-fatigue life.
A creep cavity growth model for creep-fatigue life prediction of a unidirectional W/Cu composite
NASA Technical Reports Server (NTRS)
Kim, Young-Suk; Verrilli, Michael J.; Halford, Gary R.
1992-01-01
A microstructural model was developed to predict creep-fatigue life in a (0)(sub 4), 9 volume percent tungsten fiber-reinforced copper matrix composite at the temperature of 833 K. The mechanism of failure of the composite is assumed to be governed by the growth of quasi-equilibrium cavities in the copper matrix of the composite, based on the microscopically observed failure mechanisms. The methodology uses a cavity growth model developed for prediction of creep fracture. Instantaneous values of strain rate and stress in the copper matrix during fatigue cycles were calculated and incorporated in the model to predict cyclic life. The stress in the copper matrix was determined by use of a simple two-bar model for the fiber and matrix during cyclic loading. The model successfully predicted the composite creep-fatigue life under tension-tension cyclic loading through the use of this instantaneous matrix stress level. Inclusion of additional mechanisms such as cavity nucleation, grain boundary sliding, and the effect of fibers on matrix-stress level would result in more generalized predictions of creep-fatigue life.
Definition of Life Sciences laboratories for shuttle/Spacelab. Volume 1: Executive summary
NASA Technical Reports Server (NTRS)
1975-01-01
Research requirements and the laboratories needed to support a Life Sciences research program during the shuttle/Spacelab era were investigated. A common operational research equipment inventory was developed to support a comprehensive but flexible Life Sciences program. Candidate laboratories and operational schedules were defined and evaluated in terms of accomodation with the Spacelab and overall program planning. Results provide a firm foundation for the initiation of a life science program for the shuttle era.
Computational structural mechanics for engine structures
NASA Technical Reports Server (NTRS)
Chamis, Christos C.
1988-01-01
The computational structural mechanics (CSM) program at Lewis encompasses the formulation and solution of structural mechanics problems and the development of integrated software systems to computationally simulate the performance, durability, and life of engine structures. It is structured to supplement, complement, and, whenever possible, replace costly experimental efforts. Specific objectives are to investigate unique advantages of parallel and multiprocessing for reformulating and solving structural mechanics and formulating and solving multidisciplinary mechanics and to develop integrated structural system computational simulators for predicting structural performance, evaluating newly developed methods, and identifying and prioritizing improved or missing methods.
Computational structural mechanics for engine structures
NASA Technical Reports Server (NTRS)
Chamis, Christos C.
1989-01-01
The computational structural mechanics (CSM) program at Lewis encompasses the formulation and solution of structural mechanics problems and the development of integrated software systems to computationally simulate the performance, durability, and life of engine structures. It is structured to supplement, complement, and, whenever possible, replace costly experimental efforts. Specific objectives are to investigate unique advantages of parallel and multiprocessing for reformulating and solving structural mechanics and formulating and solving multidisciplinary mechanics and to develop integrated structural system computational simulators for predicting structural performance, evaluating newly developed methods, and identifying and prioritizing improved or missing methods.
Lightweight Long Life Heat Exchanger
NASA Technical Reports Server (NTRS)
Moore, E. K.
1976-01-01
A shuttle orbiter flight configuration aluminum heat exchanger was designed, fabricated, and tested. The heat exchanger utilized aluminum clad titanium composite parting sheets for protection against parting sheet pin hole corrosion. The heat exchanger, which is fully interchangeable with the shuttle condensing heat exchanger, includes slurpers (a means for removing condensed water from the downstream face of the heat exchanger), and both the core air passes and slurpers were hydrophilic coated to enhance wettability. The test program included performance tests which demonstrated the adequacy of the design and confirmed the predicted weight savings.
Mahmood, I
1998-05-01
Extrapolation of animal data to assess pharmacokinetic parameters in man is an important tool in drug development. Clearance, volume of distribution and elimination half-life are the three most frequently extrapolated pharmacokinetic parameters. Extensive work has been done to improve the predictive performance of allometric scaling for clearance. In general there is good correlation between body weight and volume, hence volume in man can be predicted with reasonable accuracy from animal data. Besides the volume of distribution in the central compartment (Vc), two other volume terms, the volume of distribution by area (Vbeta) and the volume of distribution at steady state (VdSS), are also extrapolated from animals to man. This report compares the predictive performance of allometric scaling for Vc, Vbeta and VdSS in man from animal data. The relationship between elimination half-life (t(1/2)) and body weight across species results in poor correlation, most probably because of the hybrid nature of this parameter. To predict half-life in man from animal data, an indirect method (CL=VK, where CL=clearance, V is volume and K is elimination rate constant) has been proposed. This report proposes another indirect method which uses the mean residence time (MRT). After establishing that MRT can be predicted across species, it was used to predict half-life using the equation MRT=1.44 x t(1/2). The results of the study indicate that Vc is predicted more accurately than Vbeta and VdSS in man. It should be emphasized that for first-time dosing in man, Vc is a more important pharmacokinetic parameter than Vbeta or VdSS. Furthermore, MRT can be predicted reasonably well for man and can be used for prediction of half-life.
Life/Career Renewal: An Intervention for Vocational and Other Life Transitions.
ERIC Educational Resources Information Center
Robitschek, Christine
1997-01-01
A study examined the effectiveness of the Life/Career Renewal Program (LCR), a wilderness program for adults, in enhancing personal growth initiative (PGI) of 68 participants. Results support the hypothesis that the LCR program enhances PGI. (Author/JOW)
Predictive modeling of surimi cake shelf life at different storage temperatures
NASA Astrophysics Data System (ADS)
Wang, Yatong; Hou, Yanhua; Wang, Quanfu; Cui, Bingqing; Zhang, Xiangyu; Li, Xuepeng; Li, Yujin; Liu, Yuanping
2017-04-01
The Arrhenius model of the shelf life prediction which based on the TBARS index was established in this study. The results showed that the significant changed of AV, POV, COV and TBARS with temperature increased, and the reaction rate constants k was obtained by the first order reaction kinetics model. Then the secondary model fitting was based on the Arrhenius equation. There was the optimal fitting accuracy of TBARS in the first and the secondary model fitting (R2≥0.95). The verification test indicated that the relative error between the shelf life model prediction value and actual value was within ±10%, suggesting the model could predict the shelf life of surimi cake.
Structural Benchmark Creep Testing for the Advanced Stirling Convertor Heater Head
NASA Technical Reports Server (NTRS)
Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.; Shah, Ashwin R.
2008-01-01
The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for use on long duration Science missions such as lunar applications, Mars rovers, and deep space missions. For the inherent long life times required, a structurally significant design limit for the heater head component of the ASRG Advanced Stirling Convertor (ASC) is creep deformation induced at low stress levels and high temperatures. Demonstrating proof of adequate margins on creep deformation and rupture for the operating conditions and the MarM-247 material of construction is a challenge that the NASA Glenn Research Center is addressing. The combined analytical and experimental program ensures integrity and high reliability of the heater head for its 17-year design life. The life assessment approach starts with an extensive series of uniaxial creep tests on thin MarM-247 specimens that comprise the same chemistry, microstructure, and heat treatment processing as the heater head itself. This effort addresses a scarcity of openly available creep properties for the material as well as for the virtual absence of understanding of the effect on creep properties due to very thin walls, fine grains, low stress levels, and high-temperature fabrication steps. The approach continues with a considerable analytical effort, both deterministically to evaluate the median creep life using nonlinear finite element analysis, and probabilistically to calculate the heater head s reliability to a higher degree. Finally, the approach includes a substantial structural benchmark creep testing activity to calibrate and validate the analytical work. This last element provides high fidelity testing of prototypical heater head test articles; the testing includes the relevant material issues and the essential multiaxial stress state, and applies prototypical and accelerated temperature profiles for timely results in a highly controlled laboratory environment. This paper focuses on the last element and presents a preliminary methodology for creep rate prediction, the experimental methods, test challenges, and results from benchmark testing of a trial MarM-247 heater head test article. The results compare favorably with the analytical strain predictions. A description of other test findings is provided, and recommendations for future test procedures are suggested. The manuscript concludes with describing the potential impact of the heater head creep life assessment and benchmark testing effort on the ASC program.
2013-10-01
Based Logistics Prophets Using Science or Alchemy to Create Life-Cycle Affordability? Using Theory to Predict the Efficacy of Performance Based...Using Science or Alchemy to Create Life-Cycle Affordability? Using Theory to Predict the Efficacy of Performance Based Logistics 5a. CONTRACT NUMBER 5b...Are the PBL Prophets Using Science or Alchemy to Create Life Cycle Affordability? 328Defense ARJ, October 2013, Vol. 20 No. 3 : 325–348 Defense
TMC Behavior Modeling and Life Prediction Under Multiaxial Stresses
NASA Technical Reports Server (NTRS)
Merrick, H. F.; Aksoy, S. Z.; Costen, M.; Ahmad, J.
1998-01-01
The goal of this program was to manufacture and burst test small diameter SCS-6/Ti-6Al-4V composite rings for use in the design of an advanced titanium matrix composite (TMC) impeller. The Textron Specialty Metals grooved foil-fiber process was successfully used to make high quality TMC rings. A novel spin test arbor with "soft touch" fingers to retain the TMC ring was designed and manufactured. The design of the arbor took into account its use for cyclic experiments as well as ring burst tests. Spin testing of the instrumented ring was performed at ambient, 149C (300F), and 316C (600F) temperatures. Assembly vibration was encountered during spin testing but this was overcome through simple modification of the arbor. A spin-to-burst test was successfully completed at 316C (600F). The rotational speed of the TMC ring at burst was close to that predicted. In addition to the spin test program, a number of SCS-6/Ti-6Al-4V test panels were made. Neat Ti-6Al-4V panels also were made.
Design and Operating Characteristics of High-Speed, Small-Bore Cylindrical-Roller Bearings
NASA Technical Reports Server (NTRS)
Pinel, Stanley, I.; Signer, Hans R.; Zaretsky, Erwin V.
2000-01-01
The computer program SHABERTH was used to analyze 35-mm-bore cylindrical roller bearings designed and manufactured for high-speed turbomachinery applications. Parametric tests of the bearings were conducted on a high-speed, high-temperature bearing tester and the results were compared with the computer predictions. Bearings with a channeled inner ring were lubricated through the inner ring, while bearings with a channeled outer ring were lubricated with oil jets. Tests were run with and without outer-ring cooling. The predicted bearing life decreased with increasing speed because of increased contact stresses caused by centrifugal load. Lower temperatures, less roller skidding, and lower power losses were obtained with channeled inner rings. Power losses calculated by the SHABERTH computer program correlated reasonably well with the test results. The Parker formula for XCAV (used in SHABERTH as a measure of oil volume in the bearing cavity) needed to be adjusted to reflect the prevailing operating conditions. The XCAV formula will need to be further refined to reflect roller bearing lubrication, ring design, cage design, and location of the cage-controlling land.
Guidance on health effects of toxic chemicals. Safety Analysis Report Update Program
DOE Office of Scientific and Technical Information (OSTI.GOV)
Foust, C.B.; Griffin, G.D.; Munro, N.B.
1994-02-01
Martin Marietta Energy Systems, Inc. (MMES), and Martin Marietta Utility Services, Inc. (MMUS), are engaged in phased programs to update the safety documentation for the existing US Department of Energy (DOE)-owned facilities. The safety analysis of potential toxic hazards requires a methodology for evaluating human health effects of predicted toxic exposures. This report provides a consistent set of health effects and documents toxicity estimates corresponding to these health effects for some of the more important chemicals found within MMES and MMUS. The estimates are based on published toxicity information and apply to acute exposures for an ``average`` individual. The healthmore » effects (toxicological endpoints) used in this report are (1) the detection threshold; (2) the no-observed adverse effect level; (3) the onset of irritation/reversible effects; (4) the onset of irreversible effects; and (5) a lethal exposure, defined to be the 50% lethal level. An irreversible effect is defined as a significant effect on a person`s quality of life, e.g., serious injury. Predicted consequences are evaluated on the basis of concentration and exposure time.« less
NASA Astrophysics Data System (ADS)
Hartmann Siantar, Christine L.; Moses, Edward I.
1998-11-01
When using radiation to treat cancer, doctors rely on physics and computer technology to predict where the radiation dose will be deposited in the patient. The accuracy of computerized treatment planning plays a critical role in the ultimate success or failure of the radiation treatment. Inaccurate dose calculations can result in either insufficient radiation for cure, or excessive radiation to nearby healthy tissue, which can reduce the patient's quality of life. This paper describes how advanced physics, computer, and engineering techniques originally developed for nuclear weapons and high-energy physics research are being used to predict radiation dose in cancer patients. Results for radiation therapy planning, achieved in the Lawrence Livermore National Laboratory (LLNL) 0143-0807/19/6/005/img2 program show that these tools can give doctors new insights into their patients' treatments by providing substantially more accurate dose distributions than have been available in the past. It is believed that greater accuracy in radiation therapy treatment planning will save lives by improving doctors' ability to target radiation to the tumour and reduce suffering by reducing the incidence of radiation-induced complications.
2015-05-01
provide a cross section of the types of programs and activities the Council oversees. Specifically, we selected the B61 -12 life-extension program; the... B61 -12 life-extension program; the W76-1 life-extension program; the plutonium strategy; and budget- related activities,7 such as the Council’s
Anticipatory guidance as a principle of faculty development: managing transition and change.
Schor, Nina F; Guillet, Ronnie; McAnarney, Elizabeth R
2011-10-01
Although one cannot anticipate every individual's unique responses to the transitions and changes that regularly occur in academic medicine, a department-wide faculty development program, based on predictable transition points and supporting faculty at all levels, can minimize such negative responses to change as stress and burnout. In 2007, the authors implemented a new, formal faculty development program in the pediatrics department built on the principle of anticipatory guidance, defined as providing guidance in anticipation of future academic events. The primary components of the program are mentoring committees for individual junior faculty, group leadership development and teaching forums for midlevel faculty, and events that focus on life and career changes for senior faculty. Other department-wide activities augment the program, including review of grant submissions, annual review by a senior faculty committee of the progress of National Institutes of Health mentored research (K-) awardees, women faculty luncheons, and discussions about faculty development at regular faculty meetings. The department's faculty also participate in the University of Rochester Medical Center's active faculty development program. Feedback on the faculty development program has been constructive and mainly positive and will serve to guide the continuing evolution of the program.
Temperament and Parenting during the First Year of Life Predict Future Child Conduct Problems
ERIC Educational Resources Information Center
Lahey, Benjamin B.; Van Hulle, Carol A.; Keenan, Kate; Rathouz, Paul J.; D'Onofrio, Brian M.; Rodgers, Joseph Lee; Waldman, Irwin D.
2008-01-01
Predictive associations between parenting and temperament during the first year of life and child conduct problems were assessed longitudinally in 1,863 offspring of a representative sample of women. Maternal ratings of infant fussiness, activity level, predictability, and positive affect each independently predicted maternal ratings of conduct…
NASA Astrophysics Data System (ADS)
Kundu, Pradeep; Nath, Tameshwer; Palani, I. A.; Lad, Bhupesh K.
2018-06-01
The present paper tackles an important but unmapped problem of the reliability estimations of smart materials. First, an experimental setup is developed for accelerated life testing of the shape memory alloy (SMA) springs. Generalized log-linear Weibull (GLL-Weibull) distribution-based novel approach is then developed for SMA spring life estimation. Applied stimulus (voltage), elongation and cycles of operation are used as inputs for the life prediction model. The values of the parameter coefficients of the model provide better interpretability compared to artificial intelligence based life prediction approaches. In addition, the model also considers the effect of operating conditions, making it generic for a range of the operating conditions. Moreover, a Bayesian framework is used to continuously update the prediction with the actual degradation value of the springs, thereby reducing the uncertainty in the data and improving the prediction accuracy. In addition, the deterioration of material with number of cycles is also investigated using thermogravimetric analysis and scanning electron microscopy.
Carter, Kenneth; Olshan-Perlmutter, Michelle; Marx, Jonathan; Martini, Janet F.; Cairns, Simon B.
2017-01-01
The National Acupuncture Detoxification Association protocol (NADA) is an adjunctive therapy using 1 to 5 invariant ear acupuncture/acupressure points. This is a randomized prospective study to determine if NADA plus traditional treatment enhance outcomes: quality of life, depression, anxiety and abstinence from substance abuse. There were 100 patients enrolled in the Keystone Substance Abuse Services-Winthrop University Department of Sociology and Anthropology NADA study. All patients completed Generalized Anxiety Disorder scale (GAD-7), Patient Health Questionnaire (PHQ-9), Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES) prior to starting the program and at program completion. Patients self-reported alcohol, tobacco, and drug use prior to starting the program at program completion and at 3 and 6 month follow- up. Patient characteristics are predictive of completion versus non-completion when race, criminal history and initial drug test is considered. Those identified as nonwhite, (p < 0.05) and patients with positive initial drug test, (p < 0.01) were more likely to complete treatment in the NADA group. Also, among patients with criminal history a higher percentage failed to complete the program in the control group (p < 0.05). Participation in NADA positively associated with Q-LES score (p < 0.05), feeling better about oneself and improved energy (p < 0.05), likelihood of employment upon discharge (p < 0.05), and decreased alcohol use at 3 month follow up (p < 0.05) and 6-month follow-up (p < 0.01). NADA group reported less tobacco use at 6 months (p < 0.05). PMID:28621706
Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-14
... OFFICE OF PERSONNEL MANAGEMENT Federal Employees' Group Life Insurance Program: New Federal Employees' Group Life Insurance (FEGLI) Premiums AGENCY: Office of Personnel Management. ACTION: Notice... [[Page 70511
34 CFR 490.1 - What is the Life Skills for State and Local Prisoners Program?
Code of Federal Regulations, 2011 CFR
2011-07-01
... 34 Education 3 2011-07-01 2011-07-01 false What is the Life Skills for State and Local Prisoners... (Continued) OFFICE OF VOCATIONAL AND ADULT EDUCATION, DEPARTMENT OF EDUCATION LIFE SKILLS FOR STATE AND LOCAL PRISONERS PROGRAM General § 490.1 What is the Life Skills for State and Local Prisoners Program? The...
34 CFR 490.1 - What is the Life Skills for State and Local Prisoners Program?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 34 Education 3 2010-07-01 2010-07-01 false What is the Life Skills for State and Local Prisoners... (Continued) OFFICE OF VOCATIONAL AND ADULT EDUCATION, DEPARTMENT OF EDUCATION LIFE SKILLS FOR STATE AND LOCAL PRISONERS PROGRAM General § 490.1 What is the Life Skills for State and Local Prisoners Program? The...
Deng, Hailong; Li, Wei; Sakai, Tatsuo; Sun, Zhenduo
2015-12-02
The unexpected failures of structural materials in very high cycle fatigue (VHCF) regime have been a critical issue in modern engineering design. In this study, the VHCF property of a Cr-Ni-W gear steel was experimentally investigated under axial loading with the stress ratio of R = -1, and a life prediction model associated with crack initiation and growth behaviors was proposed. Results show that the Cr-Ni-W gear steel exhibits the constantly decreasing S-N property without traditional fatigue limit, and the fatigue strength corresponding to 10⁸ cycles is around 485 MPa. The inclusion-fine granular area (FGA)-fisheye induced failure becomes the main failure mechanism in the VHCF regime, and the local stress around the inclusion play a key role. By using the finite element analysis of representative volume element, the local stress tends to increase with the increase of elastic modulus difference between inclusion and matrix. The predicted crack initiation life occupies the majority of total fatigue life, while the predicted crack growth life is only accounts for a tiny fraction. In view of the good agreement between the predicted and experimental results, the proposed VHCF life prediction model involving crack initiation and growth can be acceptable for inclusion-FGA-fisheye induced failure.
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.
Vleugels, Jasper L A; Greuter, Marjolein J E; Hazewinkel, Yark; Coupé, Veerle M H; Dekker, Evelien
2017-12-01
In an optical diagnosis strategy, diminutive polyps that are endoscopically characterized with high confidence are removed without histopathological analysis and distal hyperplastic polyps are left in situ. We evaluated the effectiveness and costs of optical diagnosis. Using the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model, we simulated biennial fecal immunochemical test (FIT) screening in individuals aged 55 - 75 years. In this program, we compared an optical diagnosis strategy with current histopathology assessment of all diminutive polyps. Base-case assumptions included 76 % high-confidence predictions and sensitivities of 88 %, 91 %, and 88 % for endoscopically characterizing adenomas, sessile serrated polyps, and hyperplastic polyps, respectively. Outcomes were colorectal cancer burden, number of colonoscopies, life-years, and costs. Both the histopathology strategy and the optical diagnosis strategy resulted in 21 life-days gained per simulated individual compared with no screening. For optical diagnosis, €6 per individual was saved compared with the current histopathology strategy. These cost savings were related to a 31 % reduction in colonoscopies in which histopathology was needed for diminutive polyps. Projecting these results onto the Netherlands (17 million inhabitants), assuming a fully implemented FIT-based screening program, resulted in an annual undiscounted cost saving of € 1.7 - 2.2 million for optical diagnosis. Implementation of optical diagnosis in a FIT-based screening program saves costs without decreasing program effectiveness when compared with current histopathology analysis of all diminutive polyps. Further work is required to evaluate how endoscopists participating in a screening program should be trained, audited, and monitored to achieve adequate competence in optical diagnosis.
Life history theory predicts fish assemblage response to hydrologic regimes.
Mims, Meryl C; Olden, Julian D
2012-01-01
The hydrologic regime is regarded as the primary driver of freshwater ecosystems, structuring the physical habitat template, providing connectivity, framing biotic interactions, and ultimately selecting for specific life histories of aquatic organisms. In the present study, we tested ecological theory predicting directional relationships between major dimensions of the flow regime and life history composition of fish assemblages in perennial free-flowing rivers throughout the continental United States. Using long-term discharge records and fish trait and survey data for 109 stream locations, we found that 11 out of 18 relationships (61%) tested between the three life history strategies (opportunistic, periodic, and equilibrium) and six hydrologic metrics (two each describing flow variability, predictability, and seasonality) were statistically significant (P < or = 0.05) according to quantile regression. Our results largely support a priori hypotheses of relationships between specific flow indices and relative prevalence of fish life history strategies, with 82% of all significant relationships observed supporting predictions from life history theory. Specifically, we found that (1) opportunistic strategists were positively related to measures of flow variability and negatively related to predictability and seasonality, (2) periodic strategists were positively related to high flow seasonality and negatively related to variability, and (3) the equilibrium strategists were negatively related to flow variability and positively related to predictability. Our study provides important empirical evidence illustrating the value of using life history theory to understand both the patterns and processes by which fish assemblage structure is shaped by adaptation to natural regimes of variability, predictability, and seasonality of critical flow events over broad biogeographic scales.
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.
Strategies Used in Coping With a Cancer Diagnosis Predict Meaning in Life for Survivors
Jim, Heather S.; Richardson, Susan A.; Golden-Kreutz, Deanna M.; Andersen, Barbara L.
2007-01-01
The search for meaning in life is part of the human experience. A negative life event may threaten perceptions about meaning in life, such as the benevolence of the world and one’s sense of harmony and peace. The authors examined the longitudinal relationship between women’s coping with a diagnosis of breast cancer and their self-reported meaning in life 2 years later. Multiple regression analyses revealed that positive strategies for coping predicted significant variance in the sense of meaning in life—feelings of inner peace, satisfaction with one’s current life and the future, and spirituality and faith—and the absence of such strategies predicted reports of loss of meaning and confusion (ps < .01). The importance and process of finding meaning in the context of a life stressor are discussed. PMID:17100503
Assessment of fatigue life of remanufactured impeller based on FEA
NASA Astrophysics Data System (ADS)
Xu, Lei; Cao, Huajun; Liu, Hailong; Zhang, Yubo
2016-09-01
Predicting the fatigue life of remanufactured centrifugal compressor impellers is a critical problem. In this paper, the S-N curve data were obtained by combining experimentation and theory deduction. The load spectrum was compiled by the rain-flow counting method based on the comprehensive consideration of the centrifugal force, residual stress, and aerodynamic loads in the repair region. A fatigue life simulation model was built, and fatigue life was analyzed based on the fatigue cumulative damage rule. Although incapable of providing a high-precision prediction, the simulation results were useful for the analysis of fatigue life impact factors and fatigue fracture areas. Results showed that the load amplitude greatly affected fatigue life, the impeller was protected from running at over-speed, and the predicted fatigue life was satisfied within the next service cycle safely at the rated speed.
Ogama, Noriko; Yoshida, Masaki; Nakai, Toshiharu; Niida, Shumpei; Toba, Kenji; Sakurai, Takashi
2016-02-01
Lower urinary tract symptoms often limit activities of daily life and impair quality of life in the elderly. The purpose of the present study was to determine whether regional white matter hyperintensity (WMH) can predict lower urinary tract symptoms in elderly with amnestic mild cognitive impairment or Alzheimer's disease. The participants were 461 patients aged 65-85 years diagnosed with amnestic mild cognitive impairment or Alzheimer's disease. Patients and their caregivers were asked about symptoms of lower urinary tract symptoms (urinary difficulty, frequency and incontinence). Cognition, behavior and psychological symptoms of dementia and medication were evaluated. WMH and brain atrophy were analyzed using an automatic segmentation program. Regional WMH was evaluated in the frontal, parietal, temporal and occipital lobes. Patients with urinary incontinence showed significantly greater volume of WMH. WMH increased with age, especially in the frontal lobe. WMH in the frontal lobe was closely associated with urinary incontinence after adjustment for brain atrophy and classical confounding factors. Frontal WMH was a predictive factor for urinary incontinence in older adults with amnestic mild cognitive impairment or Alzheimer's disease. Urinary incontinence in demented older adults is not an incidental event, and careful insight into regional WMH on brain magnetic resonance imaging might greatly help in diagnosing individuals with a higher risk of urinary incontinence. © 2015 Japan Geriatrics Society.
Publications of the exobiology program for 1990: A special bibliography
NASA Technical Reports Server (NTRS)
1992-01-01
The Exobiology Program is an integrated program designed to investigate and understand those processes related to the origin, evolution, and distribution of life in the universe. The Exobiology Program is broad in scope, covering the following subject areas: cosmic evolution of biogenic compounds; prebiotic evolution; early evolution of life; evolution of advanced life; solar system exploration; search for extraterrestrial intelligence; planetary protection; and advanced programs in biological systems research. A listing of the 1990 publications resulting from research supported by the Exobiology Program is presented.
Viktorov, A A; Zharinov, G M; Neklasova, N Ju; Morozova, E E
2017-01-01
The article presents a methodical approach for prediction of life expectancy for people diagnosed with prostate cancer based on the kinetic theory of aging of living systems. The life expectancy is calculated by solving the differential equation for the rate of aging for three different stage of life - «normal» life, life with prostate cancer and life after combination therapy for prostate cancer. The mathematical model of aging for each stage of life has its own parameters identified by the statistical analysis of healthcare data from the Zharinov's databank and Rosstat CDR NES databank. The core of the methodical approach is the statistical correlation between growth rate of the prostate specific antigen level (PSA-level) or the PSA doubling time (PSA DT) before therapy, and lifespan: the higher the PSA DT is, the greater lifespan. The patients were grouped under the «fast PSA DT» and «slow PSA DT» categories. The satisfactory matching between calculations and experiment is shown. The prediction error of group life expectancy is due to the completeness and reliability of the main data source. A detailed monitoring of the basic health indicators throughout the each person life in each analyzed group is required. The absence of this particular information makes it impossible to predict the individual life expectancy.
Enoch, M-A; Steer, C D; Newman, T K; Gibson, N; Goldman, D
2010-02-01
Several, but not all, studies have shown that the monoamine oxidase A functional promoter polymorphism (MAOA-LPR) interacts with childhood adversity to predict adolescent and adult antisocial behavior. However, it is not known whether MAOA-LPR interacts with early life (pre-birth-3 years) stressors to influence behavior in prepubertal children. The Avon Longitudinal Study of Parents and Children, UK, is a community-representative cohort study of children followed from pre-birth onwards. The impact of family adversity from pre-birth to age 3 years and stressful life events from 6 months to 7 years on behavioral disinhibition was determined in 7500 girls and boys. Behavioral disinhibition measures were: mother-reported hyperactivity and conduct disturbances (Strengths and Difficulties Questionnaire) at ages 4 and 7 years. In both sexes, exposure to family adversity and stressful life events in the first 3 years of life predicted behavioral disinhibition at age 4, persisting until age 7. In girls, MAOA-LPR interacted with stressful life events experienced from 6 months to 3.5 years to influence hyperactivity at ages 4 and 7. In boys, the interaction of MAOA-LPR with stressful life events between 1.5 and 2.5 years predicted hyperactivity at age 7 years. The low activity MAOA-LPR variant was associated with increased hyperactivity in girls and boys exposed to high stress. In contrast, there was no MAOA-LPR interaction with family adversity. In a general population sample of prepubertal children, exposure to common stressors from pre-birth to 3 years predicted behavioral disinhibition, and MAOA-LPR- stressful life event interactions specifically predicted hyperactivity.
Perozek, Maria
2008-02-01
Old-age mortality is notoriously difficult to predict because it requires not only an understanding of the process of senescence-which is influenced by genetic, environmental, and behavioral factors-but also a prediction of how these factors will evolve. In this paper I argue that individuals are uniquely qualified to predict their own mortality based on their own genetic background, as well as environmental and behavioral risk factors that are often known only to the individual. Given this private information, individuals form expectations about survival probabilities that may provide additional information to demographers and policymakers in their challenge to predict mortality. From expectations data from the 1992 Health and Retirement Study (HRS), I construct subjective, cohort life tables that are shown to predict the unusual direction of revisions to U.S. life expectancy by gender between 1992 and 2004: that is, for these cohorts, the Social Security Actuary (SSA) raised male life expectancy in 2004 and at the same lowered female life expectancy, narrowing the gender gap in longevity by 25% over this period. Further, although the subjective life expectancies for men appear to be roughly in line with the 2004 life tables, the subjective expectations of women suggest that female life expectancies estimated by the SSA might still be on the high side.
Waterman, Kenneth Craig
2011-09-01
An isoconversion paradigm, where times in different temperature and humidity-controlled stability chambers are set to provide a fixed degradant level, is shown to compensate for the complex, non-single order kinetics of solid drug products. A humidity-corrected Arrhenius equation provides reliable estimates for temperature and relative humidity effects on degradation rates. A statistical protocol is employed to determine best fits for chemical stability data, which in turn allows for accurate estimations of shelf life (with appropriate confidence intervals) at any storage condition including inside packaging (based on the moisture vapor transmission rate of the packaging and moisture sorption isotherms of the internal components). These methodologies provide both faster results and far better predictions of chemical stability limited shelf life (expiry) than previously possible. Precise shelf-life estimations are generally determined using a 2-week, product-specific protocol. Once the model for a product is developed, it can play a critical role in providing the product understanding necessary for a quality by design (QbD) filing for product approval and enable rational control strategies to assure product stability. Moreover, this Accelerated Stability Assessment Program (ASAP) enables the coupling of product attributes (e.g., moisture content, packaging options) to allow for flexibility in how control strategies are implemented to provide a balance of cost, speed, and other factors while maintaining adequate stability.
Li, Xiao-miao; Zhang, Fang-fang; Sun, Xin-ying; Gao, Wen-bin
2010-06-18
To explore the relationship between lifestyle, self-esteem and life satisfaction among Chinese adolescents. 10 899 adolescents in middle schools and colleges from 9 provinces in China were investigated by using Chinese Adolescent Lifestyle Scale (CALS), Rosenberg Self-Esteem Scale (SES). The distribution of adolescents in the four groups divided by lifestyle and life satisfaction scores were different regarding the area and grade of these students(chi(2)=248.93, P<0.01;chi(2)=568.53, P<0.01). A high percentage of adolescents in cities (58.9%) reported a healthy life style with high life satisfaction while most adolescents in rural areas (58.9%) reported poor life styles with little satisfaction. A high percentage of junior high school students (61.8%) reported a healthy life style with high life satisfaction, but this percentage among senior high school and college students was down to 48.5% and 21.3% respectively. About 7.6% of senior high school students reported a healthy life style but poor satisfaction, a little higher than that of junior high school students (4.1%) and college students (3.6%). Moreover, there were 71.6% college students reported that they lead a poor life style with little satisfaction. The lifestyle is significantly correlated with self-esteem (r=0.472, P<0.01) and life satisfaction(r=0.636, P<0.01), and self-esteem is also significantly correlated with life satisfaction (r=0.450, P<0.01). self-esteem was the mediator of the other two parameters. The lifestyle predicts life satisfaction through self-esteem. Area and grade differences have to be taken into consideration when introducing programs on health promotion, and attention should be attached to the influence of psychological factors.
Wubshet, Mamo; Berhane, Yemane; Worku, Alemayehu; Kebede, Yigzaw
2014-07-01
In treating HIV as a chronic disease, monitoring changes of quality of life of patient's overtime is important for clinicians and policy makers. However, to our knowledge little research attention has been directed towards examining the longitudinal change of quality of life overtime in sub-Saharan Africa. To examine longitudinal changes in quality of life among patients initiated ART METHOD: A prospective longitudinal follow-up study was conducted from December 2009 to August 2011 to evaluate the changes in quality of life and how this relates with baseline socio-demographic and clinical characteristics among consecutive adult ART naïve patients attending ART clinic. Quality of life was measured by WHOQOL-HIV BREF. All quality of life domain scores improved significantly during 12 month follow-up in the ART program. At each follow-up visit, scores were significantly higher than baseline scores (p < 0.001). Predictors of improved quality of life were male gender, disclosure of HIV status, starting ART at higher CD4, > 200 cells/μL, and good baseline overall quality of life, whereas predictors of poor quality of life were starting ART with advanced disease stage and tuberculosis co-infection. This study demonstrated that the quality of life improved overtime for HIV-infected individuals receiving ART which is consistent with previous studies. It also provided information regarding the predictive effects of baseline socio-demographic and clinical factors on the changes in quality of life at the 12-month follow-up time. The finding of the study has implications of starting ART at a higher CD4 and early stage of the disease for better quality of life outcomes.
NASA Technical Reports Server (NTRS)
Effinger, M.; Ellingson, B.; Spohnholtz, T.; Koenig, J.
2001-01-01
An idea is put forth for a nondestructive characterization (NDC) generated algorithm-N curve to replace a S-N curve. A scenario for NDC life determination has been proposed. There are many challenges for the NDC life determination and prediction, but it could yield a grand payoff. The justification for NDC life determination and prediction is documented.
The fatigue life prediction of aluminium alloy using genetic algorithm and neural network
NASA Astrophysics Data System (ADS)
Susmikanti, Mike
2013-09-01
The behavior of the fatigue life of the industrial materials is very important. In many cases, the material with experiencing fatigue life cannot be avoided, however, there are many ways to control their behavior. Many investigations of the fatigue life phenomena of alloys have been done, but it is high cost and times consuming computation. This paper report the modeling and simulation approaches to predict the fatigue life behavior of Aluminum Alloys and resolves some problems of computation. First, the simulation using genetic algorithm was utilized to optimize the load to obtain the stress values. These results can be used to provide N-cycle fatigue life of the material. Furthermore, the experimental data was applied as input data in the neural network learning, while the samples data were applied for testing of the training data. Finally, the multilayer perceptron algorithm is applied to predict whether the given data sets in accordance with the fatigue life of the alloy. To achieve rapid convergence, the Levenberg-Marquardt algorithm was also employed. The simulations results shows that the fatigue behaviors of aluminum under pressure can be predicted. In addition, implementation of neural networks successfully identified a model for material fatigue life.
NASA Astrophysics Data System (ADS)
Nicholas, Jack R., Jr.; Young, R. K.
1999-03-01
This presentation provides insights of a long term 'champion' of many condition monitoring technologies and a Level III infra red thermographer. The co-authors present recommendations based on their observations of infra red and other components of predictive, condition monitoring programs in manufacturing, utility and government defense and energy activities. As predictive maintenance service providers, trainers, informal observers and formal auditors of such programs, the co-authors provide a unique perspective that can be useful to practitioners, managers and customers of advanced programs. Each has over 30 years experience in the field of machinery operation, maintenance, and support the origins of which can be traced to and through the demanding requirements of the U.S. Navy nuclear submarine forces. They have over 10 years each of experience with programs in many different countries on 3 continents. Recommendations are provided on the following: (1) Leadership and Management Support (For survival); (2) Life Cycle View (For establishment of a firm and stable foundation for a program); (3) Training and Orientation (For thermographers as well as operators, managers and others); (4) Analyst Flexibility (To innovate, explore and develop their understanding of machinery condition); (5) Reports and Program Justification (For program visibility and continued expansion); (6) Commitment to Continuous Improvement of Capability and Productivity (Through application of updated hardware and software); (7) Mutual Support by Analysts (By those inside and outside of the immediate organization); (8) Use of Multiple Technologies and System Experts to Help Define Problems (Through the use of correlation analysis of data from up to 15 technologies. An example correlation analysis table for AC and DC motors is provided.); (9) Root Cause Analysis (Allows a shift from reactive to proactive stance for a program); (10) Master Equipment Identification and Technology Application (To place the condition monitoring program in perspective); (11) Use of procedures for Predictive, Condition Monitoring and maintenance in general (To get consistent results); (12) Developing a scheme for predictive, condition monitoring personnel qualification and certification (To provide a career path and incentive to advance skill level and value to the company); (13) Analyst Assignment to Technologies and Related Duties (To make intelligent use of the skills of individuals assigned); (14) Condition Monitoring Analyst Selection Criteria (Key attributes for success are mentioned.); (15) Design and Modification to Support Monitoring (For old and new machinery to facilitate data acquisition); (16) Establishment of a Museum of Components and Samples Pulled from Service for Cause (For orientation and awareness training of operators and managers and exchange of information between analysts); (17) Goals (To promote a proactive program approach for machinery condition improvement).
Structural Optimization Methodology for Rotating Disks of Aircraft Engines
NASA Technical Reports Server (NTRS)
Armand, Sasan C.
1995-01-01
In support of the preliminary evaluation of various engine technologies, a methodology has been developed for structurally designing the rotating disks of an aircraft engine. The structural design methodology, along with a previously derived methodology for predicting low-cycle fatigue life, was implemented in a computer program. An interface computer program was also developed that gathers the required data from a flowpath analysis program (WATE) being used at NASA Lewis. The computer program developed for this study requires minimum interaction with the user, thus allowing engineers with varying backgrounds in aeropropulsion to successfully execute it. The stress analysis portion of the methodology and the computer program were verified by employing the finite element analysis method. The 10th- stage, high-pressure-compressor disk of the Energy Efficient Engine Program (E3) engine was used to verify the stress analysis; the differences between the stresses and displacements obtained from the computer program developed for this study and from the finite element analysis were all below 3 percent for the problem solved. The computer program developed for this study was employed to structurally optimize the rotating disks of the E3 high-pressure compressor. The rotating disks designed by the computer program in this study were approximately 26 percent lighter than calculated from the E3 drawings. The methodology is presented herein.
Good Self-Control as a Buffering Agent for Adolescent Substance Use
Wills, Thomas A.; Ainette, Michael G.
2008-01-01
We tested the prediction that self-control will have buffering effects for adolescent substance use (tobacco, alcohol, and marijuana) with regard to three risk factors: family life events, adolescent life events, and peer substance use. Participants were a sample of public school students (N = 1,767) who were surveyed at four yearly intervals between 6th grade and 9th grade. Good self-control was assessed with multiple indicators including planning and problem solving. Results showed that the impact of all three risk factors on substance use was reduced among persons with higher scores on good self-control. Buffering was found in cross-sectional analyses with multiple regression and in longitudinal analyses in a latent growth model with time-varying covariates. Implications for addressing self-control in prevention programs are discussed. PMID:19071971
Computational Methods for Failure Analysis and Life Prediction
NASA Technical Reports Server (NTRS)
Noor, Ahmed K. (Compiler); Harris, Charles E. (Compiler); Housner, Jerrold M. (Compiler); Hopkins, Dale A. (Compiler)
1993-01-01
This conference publication contains the presentations and discussions from the joint UVA/NASA Workshop on Computational Methods for Failure Analysis and Life Prediction held at NASA Langley Research Center 14-15 Oct. 1992. The presentations focused on damage failure and life predictions of polymer-matrix composite structures. They covered some of the research activities at NASA Langley, NASA Lewis, Southwest Research Institute, industry, and universities. Both airframes and propulsion systems were considered.
Cooled variable-area radial turbine technology program
NASA Technical Reports Server (NTRS)
Large, G. D.; Meyer, L. J.
1982-01-01
The objective of this study was a conceptual evaluation and design analyses of a cooled variable-area radial turbine capable of maintaining nearly constant high efficiency when operated at a constant speed and pressure ratio over a range of flows corresponding to 50- to 100-percent maximum engine power. The results showed that a 1589K (2400 F) turbine was feasible that would satisfy a 4000-hour duty cycle life goal. The final design feasibility is based on 1988 material technology goals. A peak aerodynamic stage total efficiency of 0.88 was predicted at 100 percent power. Two candidate stators were identified: an articulated trailing-edge and a locally movable sidewall. Both concepts must be experimentally evaluated to determine the optimum configuration. A follow-on test program is proposed for this evaluation.
Recent developments of the NESSUS probabilistic structural analysis computer program
NASA Technical Reports Server (NTRS)
Millwater, H.; Wu, Y.-T.; Torng, T.; Thacker, B.; Riha, D.; Leung, C. P.
1992-01-01
The NESSUS probabilistic structural analysis computer program combines state-of-the-art probabilistic algorithms with general purpose structural analysis methods to compute the probabilistic response and the reliability of engineering structures. Uncertainty in loading, material properties, geometry, boundary conditions and initial conditions can be simulated. The structural analysis methods include nonlinear finite element and boundary element methods. Several probabilistic algorithms are available such as the advanced mean value method and the adaptive importance sampling method. The scope of the code has recently been expanded to include probabilistic life and fatigue prediction of structures in terms of component and system reliability and risk analysis of structures considering cost of failure. The code is currently being extended to structural reliability considering progressive crack propagation. Several examples are presented to demonstrate the new capabilities.
One- and two-stage Arrhenius models for pharmaceutical shelf life prediction.
Fan, Zhewen; Zhang, Lanju
2015-01-01
One of the most challenging aspects of the pharmaceutical development is the demonstration and estimation of chemical stability. It is imperative that pharmaceutical products be stable for two or more years. Long-term stability studies are required to support such shelf life claim at registration. However, during drug development to facilitate formulation and dosage form selection, an accelerated stability study with stressed storage condition is preferred to quickly obtain a good prediction of shelf life under ambient storage conditions. Such a prediction typically uses Arrhenius equation that describes relationship between degradation rate and temperature (and humidity). Existing methods usually rely on the assumption of normality of the errors. In addition, shelf life projection is usually based on confidence band of a regression line. However, the coverage probability of a method is often overlooked or under-reported. In this paper, we introduce two nonparametric bootstrap procedures for shelf life estimation based on accelerated stability testing, and compare them with a one-stage nonlinear Arrhenius prediction model. Our simulation results demonstrate that one-stage nonlinear Arrhenius method has significant lower coverage than nominal levels. Our bootstrap method gave better coverage and led to a shelf life prediction closer to that based on long-term stability data.
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.
NASA Technical Reports Server (NTRS)
Rutledge, Sharon K.
1999-01-01
Spacecraft in low Earth orbit (LEO) are subjected to many components of the environment, which can cause them to degrade much more rapidly than intended and greatly shorten their functional life. The atomic oxygen, ultraviolet radiation, and cross contamination present in LEO can affect sensitive surfaces such as thermal control paints, multilayer insulation, solar array surfaces, and optical surfaces. The LEO Spacecraft Materials Test (LEO-SMT) program is being conducted to assess the effects of simulated LEO exposure on current spacecraft materials to increase understanding of LEO degradation processes as well as to enable the prediction of in-space performance and durability. Using ground-based simulation facilities to test the durability of materials currently flying in LEO will allow researchers to compare the degradation evidenced in the ground-based facilities with that evidenced on orbit. This will allow refinement of ground laboratory test systems and the development of algorithms to predict the durability and performance of new materials in LEO from ground test results. Accurate predictions based on ground tests could reduce development costs and increase reliability. The wide variety of national and international materials being tested represent materials being functionally used on spacecraft in LEO. The more varied the types of materials tested, the greater the probability that researchers will develop and validate predictive models for spacecraft long-term performance and durability. Organizations that are currently participating in the program are ITT Research Institute (USA), Lockheed Martin (USA), MAP (France), SOREQ Nuclear Research Center (Israel), TNO Institute of Applied Physics (The Netherlands), and UBE Industries, Ltd. (Japan). These represent some of the major suppliers of thermal control and sensor materials currently flying in LEO. The participants provide materials that are exposed to selected levels of atomic oxygen, vacuum ultraviolet radiation, contamination, or synergistic combined environments at the NASA Lewis Research Center. Changes in characteristics that could affect mission performance or lifetime are then measured. These characteristics include changes in mass, solar absorptance, and thermal emittance. The durability of spacecraft materials from U.S. suppliers is then compared with those of materials from other participating countries. Lewis will develop and validate performance and durability prediction models using this ground data and available space data. NASA welcomes the opportunity to consider additional international participants in this program, which should greatly aid future spacecraft designers as they select materials for LEO missions.
Life History Theory and Social Deviance: The Mediating Role of Executive Function
ERIC Educational Resources Information Center
Wenner, C. J.; Bianchi, J.; Figueredo, A. J.; Rushton, J. Philippe; Jacobs, W. J.
2013-01-01
The present work examined predicted relations among Life History strategies, Executive Functions, socially antagonistic attitudes, socially antagonistic behaviors, and general intelligence. Life History (LH) theory predicts that Executive Functions and socially antagonistic attitudes and behaviors underpin an interrelated and coherent set of…
Calculation of design load for the MOD-5A 7.3 mW wind turbine system
NASA Technical Reports Server (NTRS)
Mirandy, L.; Strain, J. C.
1995-01-01
Design loads are presented for the General Electric MOD-SA wind turbine. The MOD-SA system consists of a 400 ft. diameter, upwind, two-bladed, teetered rotor connected to a 7.3 mW variable-speed generator. Fatigue loads are specified in the form of histograms for the 30 year life of the machine, while limit (or maximum) loads have been derived from transient dynamic analysis at critical operating conditions. Loads prediction was accomplished using state of the art aeroelastic analyses developed at General Electric. Features of the primary predictive tool - the Transient Rotor Analysis Code (TRAC) are described in the paper. Key to the load predictions are the following wind models: (1) yearly mean wind distribution; (2) mean wind variations during operation; (3) number of start/shutdown cycles; (4) spatially large gusts; and (5) spatially small gusts (local turbulence). The methods used to develop statistical distributions from load calculations represent an extension of procedures used in past wind programs and are believed to be a significant contribution to Wind Turbine Generator analysis. Test/theory correlations are presented to demonstrate code load predictive capability and to support the wind models used in the analysis. In addition MOD-5A loads are compared with those of existing machines. The MOD-5A design was performed by the General Electric Company, Advanced Energy Program Department, under Contract DEN3-153 with NASA Lewis Research Center and sponsored by the Department of Energy.
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.
NASA Astrophysics Data System (ADS)
Rohman, Muhamad Nur; Hidayat, Mas Irfan P.; Purniawan, Agung
2018-04-01
Neural networks (NN) have been widely used in application of fatigue life prediction. In the use of fatigue life prediction for polymeric-base composite, development of NN model is necessary with respect to the limited fatigue data and applicable to be used to predict the fatigue life under varying stress amplitudes in the different stress ratios. In the present paper, Multilayer-Perceptrons (MLP) model of neural network is developed, and Genetic Algorithm was employed to optimize the respective weights of NN for prediction of polymeric-base composite materials under variable amplitude loading. From the simulation result obtained with two different composite systems, named E-glass fabrics/epoxy (layups [(±45)/(0)2]S), and E-glass/polyester (layups [90/0/±45/0]S), NN model were trained with fatigue data from two different stress ratios, which represent limited fatigue data, can be used to predict another four and seven stress ratios respectively, with high accuracy of fatigue life prediction. The accuracy of NN prediction were quantified with the small value of mean square error (MSE). When using 33% from the total fatigue data for training, the NN model able to produce high accuracy for all stress ratios. When using less fatigue data during training (22% from the total fatigue data), the NN model still able to produce high coefficient of determination between the prediction result compared with obtained by experiment.
Vrshek-Schallhorn, S; Doane, L D; Mineka, S; Zinbarg, R E; Craske, M G; Adam, E K
2013-03-01
The cortisol awakening response (CAR) has been shown to predict major depressive episodes (MDEs) over a 1-year period. It is unknown whether this effect: (a) is stable over longer periods of time; (b) is independent of prospective stressful life events; and (c) differentially predicts first onsets or recurrences of MDEs. A total of 270 older adolescents (mean age 17.06 years at cortisol measurement) from the larger prospective Northwestern-UCLA Youth Emotion Project completed baseline diagnostic and life stress interviews, questionnaires, and a 3-day cortisol sampling protocol measuring the CAR and diurnal rhythm, as well as up to four annual follow-up interviews of diagnoses and life stress. Non-proportional person-month survival analyses revealed that higher levels of the baseline CAR significantly predict MDEs for 2.5 years following cortisol measurement. However, the strength of prediction of depressive episodes significantly decays over time, with the CAR no longer significantly predicting MDEs after 2.5 years. Elevations in the CAR did not significantly increase vulnerability to prospective major stressful life events. They did, however, predict MDE recurrences more strongly than first onsets. These results suggest that a high CAR represents a time-limited risk factor for onsets of MDEs, which increases risk for depression independently of future major stressful life events. Possible explanations for the stronger effect of the CAR for predicting MDE recurrences than first onsets are discussed.
Relationships between structural complexity, coral traits, and reef fish assemblages
NASA Astrophysics Data System (ADS)
Darling, Emily S.; Graham, Nicholas A. J.; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.; Pratchett, Morgan S.; Wilson, Shaun K.
2017-06-01
With the ongoing loss of coral cover and the associated flattening of reef architecture, understanding the links between coral habitat and reef fishes is of critical importance. Here, we investigate whether considering coral traits and functional diversity provides new insights into the relationship between structural complexity and reef fish communities, and whether coral traits and community composition can predict structural complexity. Across 157 sites in Seychelles, Maldives, the Chagos Archipelago, and Australia's Great Barrier Reef, we find that structural complexity and reef zone are the strongest and most consistent predictors of reef fish abundance, biomass, species richness, and trophic structure. However, coral traits, diversity, and life histories provided additional predictive power for models of reef fish assemblages, and were key drivers of structural complexity. Our findings highlight that reef complexity relies on living corals—with different traits and life histories—continuing to build carbonate skeletons, and that these nuanced relationships between coral assemblages and habitat complexity can affect the structure of reef fish assemblages. Seascape-level estimates of structural complexity are rapid and cost effective with important implications for the structure and function of fish assemblages, and should be incorporated into monitoring programs.
Lim, Jung-Won
2014-11-01
This study aimed to understand the dyadic relationships between family communication and quality of life (QOL) and between coping and QOL in Chinese-American and Korean-American breast cancer survivor (BCS)-family member dyads. A cross-sectional survey design was used. A total of 32 Chinese-American and Korean-American BCS-family member dyads were recruited from the California Cancer Surveillance Program and area hospitals in Los Angeles County, California, USA. The dyadic data were analyzed using a pooled regression actor-partner interdependence model. The study findings demonstrated that the survivors' general communication and use of reframing coping positively predicted their own QOL. The survivors' and family members' general communication was also a strong predictor of the family members' physical-related QOL score specifically. Meanwhile, each person's use of mobilizing coping negatively predicted his or her partner's QOL. The study findings add important information to the scarce literature on the QOL of Asian-American survivors of breast cancer. The findings suggest that Chinese-American and Korean-American BCS and their family members may benefit from interventions that enhance communication and coping within the family unit. Copyright © 2014 John Wiley & Sons, Ltd.
Park, Myonghwa; Choi, Sora; Shin, A Mi; Koo, Chul Hoi
2013-02-01
The purpose of this study was to develop a prediction model for the characteristics of older adults with depression using the decision tree method. A large dataset from the 2008 Korean Elderly Survey was used and data of 14,970 elderly people were analyzed. Target variable was depression and 53 input variables were general characteristics, family & social relationship, economic status, health status, health behavior, functional status, leisure & social activity, quality of life, and living environment. Data were analyzed by decision tree analysis, a data mining technique using SPSS Window 19.0 and Clementine 12.0 programs. The decision trees were classified into five different rules to define the characteristics of older adults with depression. Classification & Regression Tree (C&RT) showed the best prediction with an accuracy of 80.81% among data mining models. Factors in the rules were life satisfaction, nutritional status, daily activity difficulty due to pain, functional limitation for basic or instrumental daily activities, number of chronic diseases and daily activity difficulty due to disease. The different rules classified by the decision tree model in this study should contribute as baseline data for discovering informative knowledge and developing interventions tailored to these individual characteristics.
Lim, Jung-won
2014-01-01
Objective This study aimed to understand the dyadic relationships between family communication and quality of life (QOL) and between coping and QOL in Chinese- and Korean-American breast cancer survivor (BCS)-family member dyads. Methods A cross-sectional survey design was used. A total of 32 Chinese- and Korean-American BCS-family member dyads were recruited from the California Cancer Surveillance Program and area hospitals in Los Angeles County, California, United States. The dyadic data were analyzed using a pooled regression actor-partner interdependence model. Results The study findings demonstrated that the survivors’ general communication and use of reframing coping positively predicted their own QOL. The survivors’ and family members’ general communication was also a strong predictor of the family members’ physical-related QOL score specifically. Meanwhile, each person’s use of mobilizing coping negatively predicted his or her partner’s QOL. Conclusions The study findings add important information to the scarce literature on the QOL of Asian-American survivors of breast cancer. The findings suggest that Chinese- and Korean-American BCS and their family members may benefit from interventions that enhance communication and coping within the family unit. PMID:24700695
2016-09-01
Failure MTBCF Mean Time Between Critical Failure MIRV Multiple Independently-targetable Reentry Vehicle MK6LE MK6 Guidance System Life Extension...programs were the MK54 Lightweight Torpedo program, a Raytheon Radar program, and the Life Extension of the MK6 Guidance System (MK6LE) of the...activities throughout the later life -cycle phases. MBSE allowed the programs to manage the evolution of simulation capabilities, as well as to assess the
ERIC Educational Resources Information Center
Pereira, Ana Isabel; Marques, Teresa; Russo, Vanessa; Barros, Luísa; Barrett, P.
2014-01-01
The FRIENDS for Life program is a cognitive-behavioral group program that targets anxiety in children. The main purpose of this study was to analyze the effectiveness of the Portuguese version of the FRIENDS for Life Program, which was implemented in schools to reduce anxiety problems in a group of highly anxious children. The study used a…
How rare is complex life in the Milky Way?
Bounama, Christine; von Bloh, Werner; Franck, Siegfried
2007-10-01
An integrated Earth system model was applied to calculate the number of habitable Earth-analog planets that are likely to have developed primitive (unicellular) and complex (multicellular) life in extrasolar planetary systems. The model is based on the global carbon cycle mediated by life and driven by increasing stellar luminosity and plate tectonics. We assumed that the hypothetical primitive and complex life forms differed in their temperature limits and CO(2) tolerances. Though complex life would be more vulnerable to environmental stress, its presence would amplify weathering processes on a terrestrial planet. The model allowed us to calculate the average number of Earth-analog planets that may harbor such life by using the formation rate of Earth-like planets in the Milky Way as well as the size of a habitable zone that could support primitive and complex life forms. The number of planets predicted to bear complex life was found to be approximately 2 orders of magnitude lower than the number predicted for primitive life forms. Our model predicted a maximum abundance of such planets around 1.8 Ga ago and allowed us to calculate the average distance between potentially habitable planets in the Milky Way. If the model predictions are accurate, the future missions DARWIN (up to a probability of 65%) and TPF (up to 20%) are likely to detect at least one planet with a biosphere composed of complex life.
Fosco, Whitney D; Hawk, Larry W
2017-02-01
A child's ability to sustain attention over time (AOT) is critical in attention-deficit/hyperactivity disorder (ADHD), yet no prior work has examined the extent to which a child's decrement in AOT on laboratory tasks relates to clinically-relevant behavior. The goal of this study is to provide initial evidence for the criterion validity of laboratory assessments of AOT. A total of 20 children with ADHD (7-12 years of age) who were enrolled in a summer treatment program completed two lab attention tasks (a continuous performance task and a self-paced choice discrimination task) and math seatwork. Analyses focused on relations between attention task parameters and math productivity. Individual differences in overall attention (OA) measures (averaged across time) accounted for 23% of the variance in math productivity, supporting the criterion validity of lab measures of attention. The criterion validity was enhanced by consideration of changes in AOT. Performance on all laboratory attention measures deteriorated as time-on-task increased, and individual differences in the decrement in AOT accounted for 40% of the variance in math productivity. The only variable to uniquely predict math productivity was from the self-paced choice discrimination task. This study suggests that attention tasks in the lab do predict a clinically-relevant target behavior in children with ADHD, supporting their use as a means to study attention processes in a controlled environment. Furthermore, this prediction is improved when attention is examined as a function of time-on-task and when the attentional demands are consistent between lab and life contexts.
Robinson, Elizabeth A. R.; Krentzman, Amy R.; Webb, Jon R.; Brower, Kirk J.
2011-01-01
Objective: Although spiritual change is hypothesized to contribute to recovery from alcohol dependence, few studies have used prospective data to investigate this hypothesis. Prior studies have also been limited to treatment-seeking and Alcoholics Anonymous (AA) samples. This study included alcohol-dependent individuals, both in treatment and not, to investigate the effect of spiritual and religious (SR) change on subsequent drinking outcomes, independent of AA involvement. Method: Alcoholics (N = 364) were recruited for a panel study from two abstinence-based treatment centers, a moderation drinking program, and untreated individuals from the local community. Quantitative measures of SR change between baseline and 6 months were used to predict 9-month drinking outcomes, controlling for baseline drinking and AA involvement. Results: Significant 6-month changes in 8 of 12 SR measures were found, which included private SR practices, beliefs, daily spiritual experiences, three measures of forgiveness, negative religious coping, and purpose in life. Increases in private SR practices and forgiveness of self were the strongest predictors of improvements in drinking outcomes. Changes in daily spiritual experiences, purpose in life, a general measure of forgiveness, and negative religious coping also predicted favorable drinking outcomes. Conclusions: SR change predicted good drinking outcomes in alcoholics, even when controlling for AA involvement. SR variables, broadly defined, deserve attention in fostering change even among those who do not affiliate with AA or religious institutions. Last, future research should include SR variables, particularly various types of forgiveness, given the strong effects found for forgiveness of self. PMID:21683048
(Durability of building materials and components)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Naus, D.J.
1990-11-27
The traveler participated in the fourth meeting of RILEM 100-TSL, Techniques for Service Life Prediction,'' and The Fifth International Conference on Durability of Building Materials and Components.'' In addition, the traveler met with staff members at Taywood Engineering Ltd., Electricite de France, and AEA Technology. The meeting pertained to performance of concrete materials in nuclear power plant structures, time variation of concrete material properties, methods for evaluating concrete structures, and modeling to predict the effects of degradation factors on concrete materials. As many of the concrete structures in general civil engineering applications as well as nuclear power plant applications inmore » Europe are aging, there is increasing emphasis on assessing the durability of these structures. Information was provided of direct application to the Structural Aging Program which would not have been available without these visits. Of equal, or possibly more importance, was the individual contacts established at the organizations visited. Each organization was extremely interested in both the approach and scope of the Structural Aging Program and requested that they be informed of progress. The initial steps were taken to cooperate with several of these researchers and this should help the Structural Aging Program keep abreast of related European activities. In summary, information obtained during this trip will benefit the ongoing Structural Aging Program by informing Oak Ridge National Laboratory (ORNL) of the extensive European research programs addressing the durability of concrete structures, and also by forming and strengthening acquaintances with counterparts in other countries, thus enhancing the basis for possible international cooperation.« less
MYSTERIES OF THE HUMAN FETUS REVEALED
SANDMAN, CURT A
2015-01-01
The impressive program of research from the DiPietro laboratory succeeds in its aim to document the ontogeny of human fetal neurobehavioral development. From studies of great depth and breadth, and wielding creative methods of assessment, DiPietro et al open a window into the largely inaccessible developing human fetal brain. This commentary, with reference to the seminal cardiovascular studies of the Lacey's, supports the measures of the fetal heart to index fetal well-being and to provide evidence of stimulus processing. A separate case is made that the DiPietro program provides unique and invaluable information for assessing the influential Developmental Origins of Health and Disease or Fetal Programming Models. The goal of these models, to predict or understand the influences of early experience or response patterns on later postnatal life, is identical to the ultimate goal of the DiPietro program. Because human fetal behavior is uncontaminated by socialization or parenting or peers, it may be the best reflection of fetal exposures. The remarkable neurobehavioral profiles generated by the DiPietro program can make a critical contribution to the Fetal Programming Model in terms of sensitive and critical periods of nervous system vulnerability and to specify gestational periods of neurobehavioral risk.. PMID:26303720
Duncan, Robert; Washburn, Isaac J; Lewis, Kendra M; Bavarian, Niloofar; DuBois, David L; Acock, Alan C; Vuchinich, Samuel; Flay, Brian R
2017-02-01
Behavioral trajectories during middle childhood are predictive of consequential outcomes later in life (e.g., substance abuse, violence). Social and emotional learning (SEL) programs are designed to promote trajectories that reflect both growth in positive behaviors and inhibited development of negative behaviors. The current study used growth mixture models to examine effects of the Positive Action (PA) program on behavioral trajectories of social-emotional and character development (SECD) and misconduct using data from a cluster-randomized trial that involved 14 schools and a sample of predominately low-income, urban youth followed from 3rd through 8th grade. For SECD, findings indicated that PA was similarly effective at improving trajectories within latent classes characterized as "high/declining" and "low/stable". Favorable program effects were likewise evident to a comparable degree for misconduct across observed latent classes that reflected "low/rising" and "high/rising" trajectories. These findings suggest that PA and perhaps other school-based universal SEL programs have the potential to yield comparable benefits across subgroups of youth with differing trajectories of positive and negative behaviors, making them promising strategies for achieving the intended goal of school-wide improvements in student outcomes.
The effects of pulmonary rehabilitation in the national emphysema treatment trial.
Ries, Andrew L; Make, Barry J; Lee, Shing M; Krasna, Mark J; Bartels, Matthew; Crouch, Rebecca; Fishman, Alfred P
2005-12-01
Pulmonary rehabilitation is an established treatment in patients with chronic lung disease but is not widely utilized. Most trials have been conducted in single centers. The National Emphysema Treatment Trial (NETT) provided an opportunity to evaluate pulmonary rehabilitation in a large cohort of patients who were treated in centers throughout the United States. Prospective observational study of cohort prior to randomization in a multicenter clinical trial. University-based clinical centers and community-based satellite pulmonary rehabilitation programs. A total of 1,218 patients with severe emphysema underwent pulmonary rehabilitation before and after randomization to lung volume reduction surgery (LVRS) or continued medical management. Rehabilitation was conducted at 17 NETT centers supplemented by 539 satellite centers. Lung function, exercise tolerance, dyspnea, and quality of life were evaluated at regular intervals. Significant (p < 0.001) improvements were observed consistently in exercise (cycle ergometry, 3.1 W; 6-min walk test distance, 76 feet), dyspnea (University of California, San Diego Shortness of Breath Questionnaire score, -3.2; Borg breathlessness score: breathing cycle, -0.8; 6-min walk, -0.5) and quality of life (St. George Respiratory Questionnaire score, -3.5; Quality of Well-Being Scale score, +0.035; Medical Outcomes Study 36-item short form score: physical health summary, +1.3; mental health summary, + 2.0). Patients who had not undergone prior rehabilitation improved more than those who had. In multivariate models, only prior rehabilitation status predicted changes after rehabilitation. In 20% of patients, exercise level changed sufficiently after rehabilitation to alter the NETT subgroup predictive of outcome. Overall, changes after rehabilitation did not predict differential mortality or improvement in exercise (primary outcomes) by treatment group. The NETT experience demonstrates the effectiveness of pulmonary rehabilitation in patients with severe emphysema who were treated in a national cross-section of programs. Pulmonary rehabilitation plays an important role in preparing and selecting patients for surgical interventions such as LVRS.
Herbivore-mediated ecological costs of reproduction shape the life history of an iteroparous plant.
Miller, Tom E X; Tenhumberg, Brigitte; Louda, Svata M
2008-02-01
Plant reproduction yields immediate fitness benefits but can be costly in terms of survival, growth, and future fecundity. Life-history theory posits that reproductive strategies are shaped by trade-offs between current and future fitness that result from these direct costs of reproduction. Plant reproduction may also incur indirect ecological costs if it increases susceptibility to herbivores. Yet ecological costs of reproduction have received little empirical attention and remain poorly integrated into life-history theory. Here, we provide evidence for herbivore-mediated ecological costs of reproduction, and we develop theory to examine how these costs influence plant life-history strategies. Field experiments with an iteroparous cactus (Opuntia imbricata) indicated that greater reproductive effort (proportion of meristems allocated to reproduction) led to greater attack by a cactus-feeding insect (Narnia pallidicornis) and that damage by this herbivore reduced reproductive success. A dynamic programming model predicted strongly divergent optimal reproductive strategies when ecological costs were included, compared with when these costs were ignored. Meristem allocation by cacti in the field matched the optimal strategy expected under ecological costs of reproduction. The results indicate that plant reproductive allocation can strongly influence the intensity of interactions with herbivores and that associated ecological costs can play an important selective role in the evolution of plant life histories.
Exploring Life Support Architectures for Evolution of Deep Space Human Exploration
NASA Technical Reports Server (NTRS)
Anderson, Molly S.; Stambaugh, Imelda C.
2015-01-01
Life support system architectures for long duration space missions are often explored analytically in the human spaceflight community to find optimum solutions for mass, performance, and reliability. But in reality, many other constraints can guide the design when the life support system is examined within the context of an overall vehicle, as well as specific programmatic goals and needs. Between the end of the Constellation program and the development of the "Evolvable Mars Campaign", NASA explored a broad range of mission possibilities. Most of these missions will never be implemented but the lessons learned during these concept development phases may color and guide future analytical studies and eventual life support system architectures. This paper discusses several iterations of design studies from the life support system perspective to examine which requirements and assumptions, programmatic needs, or interfaces drive design. When doing early concept studies, many assumptions have to be made about technology and operations. Data can be pulled from a variety of sources depending on the study needs, including parametric models, historical data, new technologies, and even predictive analysis. In the end, assumptions must be made in the face of uncertainty. Some of these may introduce more risk as to whether the solution for the conceptual design study will still work when designs mature and data becomes available.
You, Zhiqi; Song, Juanjuan; Wu, Caizhi; Qin, Ping; Zhou, Zongkui
2014-01-01
Objectives To examine predictive power of psychache and life satisfaction on risks for suicidal ideation and suicide attempt among young people. Design A cross-sectional study. Setting Data were collected from an online survey in Wuhan, China. Participants 5988 university students from six universities were selected by a stratified cluster sampling method. Primary and secondary outcome measures Suicidal ideation and suicide attempt at some point of the students’ lifetime were the outcomes of interest. Results Students with suicidal ideation or attempted suicide reported a lower level of life satisfaction and high degree of psychache than counterparts without suicidal ideation or attempt. Regression analyses indicated that life satisfaction and psychache were significantly associated with the risk of suicidal ideation and the risk of suicidal attempt. Though psychache showed a relatively stronger predictive power than life satisfaction, the effect of the two factors remained significant when they were individually adjusted for personal demographic characteristics. However, when the two factors were included in the model simultaneously to adjust for each other, psychache could fully explain the association between life satisfaction and suicidal attempt. Life satisfaction remained to contribute unique variance in the statistical prediction of suicidal ideation. Conclusions Psychache and life satisfaction both have a significant predictive power on risk for suicidal behaviour, and life satisfaction could relieve the predictive power of psychache when suicidal behaviour is just starting. Shneidman's theory that psychache is the pre-eminent psychological cause of suicide is perhaps applicable only to a more serious form of suicidal behaviour. PMID:24657883
Enoch, Mary-Anne; Steer, Colin D.; Newman, Timothy K.; Gibson, Nerea; Goldman, David
2009-01-01
Several, but not all, studies have shown that the monoamine oxidase A functional promoter polymorphism (MAOA-LPR) interacts with childhood adversity to predict adolescent and adult antisocial behavior. However, it is not known whether MAOA-LPR interacts with early life (pre-birth – 3 years) stressors to influence behavior in pre-pubertal children. The Avon Longitudinal Study of Parents and Children, U.K., is a community-representative cohort study of children followed from pre-birth onwards. The impact of family adversity from pre-birth to age 3 years and stressful life events from 6 months to 7 years on behavioral disinhibition was determined in 7500 girls and boys. Behavioral disinhibition measures were: mother-reported hyperactivity and conduct disturbances (Strengths and Difficulties Questionnaire) at ages 4 and 7 years. In both sexes, exposure to family adversity and stressful life events in the first three years of life predicted behavioral disinhibition at age 4, persisting until age 7. In girls, MAOA-LPR interacted with stressful life events experienced from 6 months to 3 ½ years to influence hyperactivity at ages 4 and 7. In boys, the interaction of MAOA-LPR with stressful life events between 1 ½ and 2 ½ years predicted hyperactivity at age 7 years. The low activity MAOA-LPR variant was associated with increased hyperactivity in girls and boys exposed to high stress. In contrast, there was no MAOA-LPR interaction with family adversity. In a general population sample of pre-pubertal children, exposure to common stressors from pre-birth to 3 years predicted behavioral disinhibition, and MAOA-LPR - stressful life event interactions specifically predicted hyperactivity. PMID:19804559
Buvé, Carolien; Van Bedts, Tine; Haenen, Annelien; Kebede, Biniam; Braekers, Roel; Hendrickx, Marc; Van Loey, Ann; Grauwet, Tara
2018-07-01
Accurate shelf-life dating of food products is crucial for consumers and industries. Therefore, in this study we applied a science-based approach for shelf-life assessment, including accelerated shelf-life testing (ASLT), acceptability testing and the screening of analytical attributes for fast shelf-life predictions. Shelf-stable strawberry juice was selected as a case study. Ambient storage (20 °C) had no effect on the aroma-based acceptance of strawberry juice. The colour-based acceptability decreased during storage under ambient and accelerated (28-42 °C) conditions. The application of survival analysis showed that the colour-based shelf-life was reached in the early stages of storage (≤11 weeks) and that the shelf-life was shortened at higher temperatures. None of the selected attributes (a * and ΔE * value, anthocyanin and ascorbic acid content) is an ideal analytical marker for shelf-life predictions in the investigated temperature range (20-42 °C). Nevertheless, an overall analytical cut-off value over the whole temperature range can be selected. Colour changes of strawberry juice during storage are shelf-life limiting. Combining ASLT with acceptability testing allowed to gain faster insight into the change in colour-based acceptability and to perform shelf-life predictions relying on scientific data. An analytical marker is a convenient tool for shelf-life predictions in the context of ASLT. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
Pil, L; Fobelets, M; Putman, K; Trybou, J; Annemans, L
2016-07-01
Colorectal cancer (CRC) is one of the leading causes of cancer mortality in Belgium. In Flanders (Belgium), a population-based screening program with a biennial immunochemical faecal occult blood test (iFOBT) in women and men aged 56-74 has been organised since 2013. This study assessed the cost-effectiveness and budget impact of the colorectal population-based screening program in Flanders (Belgium). A health economic model was conducted, consisting of a decision tree simulating the screening process and a Markov model, with a time horizon of 20years, simulating natural progression. Predicted mortality and incidence, total costs, and quality-adjusted life-years (QALYs) with and without the screening program were calculated in order to determine the incremental cost-effectiveness ratio of CRC screening. Deterministic and probabilistic sensitivity analyses were conducted, taking into account uncertainty of the model parameters. Mortality and incidence were predicted to decrease over 20years. The colorectal screening program in Flanders is found to be cost-effective with an ICER of 1681/QALY (95% CI -1317 to 6601) in males and €4,484/QALY (95% CI -3254 to 18,163). The probability of being cost-effective given a threshold of €35,000/QALY was 100% and 97.3%, respectively. The budget impact analysis showed the extra cost for the health care payer to be limited. This health economic analysis has shown that despite the possible adverse effects of screening and the extra costs for the health care payer and the patient, the population-based screening program for CRC in Flanders is cost-effective and should therefore be maintained. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.
McPherson, Amy C; King, Gillian; Rudzik, Alanna; Kingsnorth, Shauna; Gorter, Jan Willem
2016-09-06
Young people with disabilities often lag behind their typically developing peers in the achievement of adult roles, which has been attributed to a lack of opportunities to develop critical life skills. Residential Immersive Life Skills (RILS) programs provide situated learning opportunities to develop life skills alongside peers and away from home in real-world settings. Retrospective research suggests that attending RILS programs is a transformative experience that empowers youth, provides parental hope, and increases service provider expertise. However, prospective, comparative research is needed to determine longer term benefits of these programs on youth life trajectories, in addition to exploring the program features and participant experiences that optimize program success. This protocol describes a 5-year, multi-site prospective study examining the effects of RILS programs for youth with disabilities. The study involves RILS programs at three sites in Ontario, Canada. Cohorts of treatment and control groups will receive the study protocol over 3 successive years. Thirty English-speaking participants aged 14-21 years with a child-onset disability and the cognitive capacity to engage in goal setting will be recruited every year for 3 years in the following groups: youth attending a RILS program (Group A); a deferred RILS control group of youth (Group B); a control group of youth attending a non-residential life skills program (Group C); and a control group matched on age, diagnoses, and cognitive capacity not receiving any life skills intervention (Group D). All participants will complete measures of self-determination and self-efficacy at four time points. Program opportunities and experiences will also be assessed in-the-moment at the RILS programs. Qualitative interviews pre-program and at 3- and 12-months post-program will be undertaken with a sub-sample of youth and parents to explore their expectations and experiences. This study will address key gaps in the literature pertaining to the long-term impact of RILS programs and the role of immersive environments in shaping youth outcomes and experiences. Our research program aims to uncover transferable processes and essential features by which RILS programs have their effects on attitudes, cognitions, and behaviour. The trial registration number on clinicaltrials.gov is NCT02753452 (retrospectively registered 26 April 2016). Trial sponsor: Holland Bloorview Kids Rehabilitation Hospital.
White, Barry A. B.; Temple, Judy A.; Reynolds, Arthur J.
2016-01-01
Recent analyses of the long-term societal benefits from early intervention (prenatal care, home visitation, and high quality preschool) for at-risk children commonly include significant savings to society in the form of reduced juvenile delinquency and adult criminal behavior. However, a nontrivial proportion of the reported benefits of several early intervention programs are based on forecasts of criminal behavior throughout adulthood conditional on intervention effects on delinquency in adolescence. Data from the Chicago Longitudinal Study (CLS), an investigation of the life course of 1,539 children from low-income families born in 1979–1980, are used to investigate the bias resulting from predicting the effect of early intervention on adult criminal behavior from the effect on delinquency in adolescence. The investigation concludes that the general method used to predict adult criminal behavior results in a conservative estimate of the reduction in the cost of adult criminal behavior attributed to early intervention. PMID:27867324
White, Barry A B; Temple, Judy A; Reynolds, Arthur J
2010-12-01
Recent analyses of the long-term societal benefits from early intervention (prenatal care, home visitation, and high quality preschool) for at-risk children commonly include significant savings to society in the form of reduced juvenile delinquency and adult criminal behavior. However, a nontrivial proportion of the reported benefits of several early intervention programs are based on forecasts of criminal behavior throughout adulthood conditional on intervention effects on delinquency in adolescence. Data from the Chicago Longitudinal Study (CLS), an investigation of the life course of 1,539 children from low-income families born in 1979-1980, are used to investigate the bias resulting from predicting the effect of early intervention on adult criminal behavior from the effect on delinquency in adolescence. The investigation concludes that the general method used to predict adult criminal behavior results in a conservative estimate of the reduction in the cost of adult criminal behavior attributed to early intervention.
Weight Shame, Social Connection, and Depressive Symptoms in Late Adolescence
Brewis, Alexandra A.; Bruening, Meg
2018-01-01
Child and adolescent obesity is increasingly the focus of interventions, because it predicts serious disease morbidity later in life. However, social environments that permit weight-related stigma and body shame may make weight control and loss more difficult. Rarely do youth obesity interventions address these complexities. Drawing on repeated measures in a large sample (N = 1443) of first-year (freshman), campus-resident university students across a nine-month period, we model how weight-related shame predicts depressive symptom levels, how being overweight (assessed by anthropometric measures) shapes that risk, and how social connection (openness to friendship) might mediate/moderate. Body shame directly, clearly, and repeatedly predicts depression symptom levels across the whole school year for all students, but overweight youth have significantly elevated risk. Social connections mediate earlier in the school year, and in all phases moderate, body shame effects on depression. Youth obesity interventions would be well-served recognizing and incorporating the influential roles of social-environmental factors like weight stigma and friendship in program design. PMID:29723962
Weight Shame, Social Connection, and Depressive Symptoms in Late Adolescence.
Brewis, Alexandra A; Bruening, Meg
2018-05-01
Child and adolescent obesity is increasingly the focus of interventions, because it predicts serious disease morbidity later in life. However, social environments that permit weight-related stigma and body shame may make weight control and loss more difficult. Rarely do youth obesity interventions address these complexities. Drawing on repeated measures in a large sample ( N = 1443) of first-year (freshman), campus-resident university students across a nine-month period, we model how weight-related shame predicts depressive symptom levels, how being overweight (assessed by anthropometric measures) shapes that risk, and how social connection (openness to friendship) might mediate/moderate. Body shame directly, clearly, and repeatedly predicts depression symptom levels across the whole school year for all students, but overweight youth have significantly elevated risk. Social connections mediate earlier in the school year, and in all phases moderate, body shame effects on depression. Youth obesity interventions would be well-served recognizing and incorporating the influential roles of social-environmental factors like weight stigma and friendship in program design.
NASA Astrophysics Data System (ADS)
Vlase, A.; Blăjină, O.; Iacob, M.; Darie, V.
2015-11-01
Two addressed issues in the research regarding the cutting machinability, establishing of the optimum cutting processing conditions and the optimum cutting regime, do not yet have sufficient data for solving. For this reason, in the paper it is proposed the optimization of the tool life and the cutting speed at the drilling of a certain stainless steel in terms of the maximum productivity. For this purpose, a nonlinear programming mathematical model to maximize the productivity at the drilling of the steel is developed in the paper. The optimum cutting tool life and the associated cutting tool speed are obtained by solving the numerical mathematical model. Using this proposed model allows increasing the accuracy in the prediction of the productivity for the drilling of a certain stainless steel and getting the optimum tool life and the optimum cutting speed for the maximum productivity. The results presented in this paper can be used in the production activity, in order to increase the productivity of the stainless steels machining. Also new research directions for the specialists in this interested field may come off from this paper.
Gaffney, Hannah; Mansell, Warren; Edwards, Rachel; Wright, Jason
2014-11-01
Computerized self-help that has an interactive, conversational format holds several advantages, such as flexibility across presenting problems and ease of use. We designed a new program called MYLO that utilizes the principles of METHOD of Levels (MOL) therapy--based upon Perceptual Control Theory (PCT). We tested the efficacy of MYLO, tested whether the psychological change mechanisms described by PCT mediated its efficacy, and evaluated effects of client expectancy. Forty-eight student participants were randomly assigned to MYLO or a comparison program ELIZA. Participants discussed a problem they were currently experiencing with their assigned program and completed measures of distress, resolution and expectancy preintervention, postintervention and at 2-week follow-up. MYLO and ELIZA were associated with reductions in distress, depression, anxiety and stress. MYLO was considered more helpful and led to greater problem resolution. The psychological change processes predicted higher ratings of MYLO's helpfulness and reductions in distress. Positive expectancies towards computer-based problem solving correlated with MYLO's perceived helpfulness and greater problem resolution, and this was partly mediated by the psychological change processes identified. The findings provide provisional support for the acceptability of the MYLO program in a non-clinical sample although its efficacy as an innovative computer-based aid to problem solving remains unclear. Nevertheless, the findings provide tentative early support for the mechanisms of psychological change identified within PCT and highlight the importance of client expectations on predicting engagement in computer-based self-help.
NASA Astrophysics Data System (ADS)
Zhukovskiy, Yu L.; Korolev, N. A.; Babanova, I. S.; Boikov, A. V.
2017-10-01
This article is devoted to the prediction of the residual life based on an estimate of the technical state of the induction motor. The proposed system allows to increase the accuracy and completeness of diagnostics by using an artificial neural network (ANN), and also identify and predict faulty states of an electrical equipment in dynamics. The results of the proposed system for estimation the technical condition are probability technical state diagrams and a quantitative evaluation of the residual life, taking into account electrical, vibrational, indirect parameters and detected defects. Based on the evaluation of the technical condition and the prediction of the residual life, a decision is made to change the control of the operating and maintenance modes of the electric motors.
2013-01-01
Background Gestational diabetes mellitus (GDM) is defined as glucose intolerance with its onset or first recognition during pregnancy. Post-GDM women have a life-time risk exceeding 70% of developing type 2 diabetes mellitus (T2DM). Lifestyle modifications reduce the incidence of T2DM by up to 58% for high-risk individuals. Methods/Design The Mothers After Gestational Diabetes in Australia Diabetes Prevention Program (MAGDA-DPP) is a randomized controlled trial aiming to assess the effectiveness of a structured diabetes prevention intervention for post-GDM women. This trial has an intervention group participating in a diabetes prevention program (DPP), and a control group receiving usual care from their general practitioners during the same time period. The 12-month intervention comprises an individual session followed by five group sessions at two-week intervals, and two follow-up telephone calls. A total of 574 women will be recruited, with 287 in each arm. The women will undergo blood tests, anthropometric measurements, and self-reported health status, diet, physical activity, quality of life, depression, risk perception and healthcare service usage, at baseline and 12 months. At completion, primary outcome (changes in diabetes risk) and secondary outcome (changes in psychosocial and quality of life measurements and in cardiovascular disease risk factors) will be assessed in both groups. Discussion This study aims to show whether MAGDA-DPP leads to a reduction in diabetes risk for post-GDM women. The characteristics that predict intervention completion and improvement in clinical and behavioral measures will be useful for further development of DPPs for this population. Trial registration Australian New Zealand Clinical Trials Registry ANZCTRN 12610000338066 PMID:24135085
Shih, Sophy T F; Davis-Lameloise, Nathalie; Janus, Edward D; Wildey, Carol; Versace, Vincent L; Hagger, Virginia; Asproloupos, Dino; O'Reilly, Sharleen; Phillips, Paddy A; Ackland, Michael; Skinner, Timothy; Oats, Jeremy; Carter, Rob; Best, James D; Dunbar, James A
2013-10-17
Gestational diabetes mellitus (GDM) is defined as glucose intolerance with its onset or first recognition during pregnancy. Post-GDM women have a life-time risk exceeding 70% of developing type 2 diabetes mellitus (T2DM). Lifestyle modifications reduce the incidence of T2DM by up to 58% for high-risk individuals. The Mothers After Gestational Diabetes in Australia Diabetes Prevention Program (MAGDA-DPP) is a randomized controlled trial aiming to assess the effectiveness of a structured diabetes prevention intervention for post-GDM women. This trial has an intervention group participating in a diabetes prevention program (DPP), and a control group receiving usual care from their general practitioners during the same time period. The 12-month intervention comprises an individual session followed by five group sessions at two-week intervals, and two follow-up telephone calls. A total of 574 women will be recruited, with 287 in each arm. The women will undergo blood tests, anthropometric measurements, and self-reported health status, diet, physical activity, quality of life, depression, risk perception and healthcare service usage, at baseline and 12 months. At completion, primary outcome (changes in diabetes risk) and secondary outcome (changes in psychosocial and quality of life measurements and in cardiovascular disease risk factors) will be assessed in both groups. This study aims to show whether MAGDA-DPP leads to a reduction in diabetes risk for post-GDM women. The characteristics that predict intervention completion and improvement in clinical and behavioral measures will be useful for further development of DPPs for this population. Australian New Zealand Clinical Trials Registry ANZCTRN 12610000338066.