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Sample records for allostatic load al

  1. [Structure of allostatic load in railway workers].

    PubMed

    Gorokhova, S G; Pfaf, V F; Muraseyeva, E V; Akhsanova, E R; Prigorovskaya, T S; At'kov, O Yu

    2016-01-01

    The authors studied allostatic load in railway workers, as an indicator of stress effect. Analysis covered biomarkers that form allostatic load index, and their ratio for variable allostatic load index levels. Moderate allostatic load appeared to prevail in the examinees group. Findings are that systolic and diastolic blood pressure, general cholesterol and hemoglobin make major contribution into allostatic load index. Comparison covered models of allostatic load index calculation for variable biomarkers sets.

  2. [Structure of allostatic load in railway workers].

    PubMed

    Gorokhova, S G; Pfaf, V F; Muraseyeva, E V; Akhsanova, E R; Prigorovskaya, T S; At'kov, O Yu

    2016-01-01

    The authors studied allostatic load in railway workers, as an indicator of stress effect. Analysis covered biomarkers that form allostatic load index, and their ratio for variable allostatic load index levels. Moderate allostatic load appeared to prevail in the examinees group. Findings are that systolic and diastolic blood pressure, general cholesterol and hemoglobin make major contribution into allostatic load index. Comparison covered models of allostatic load index calculation for variable biomarkers sets. PMID:27396144

  3. Allostatic load and work conditions.

    PubMed

    Schnorpfeil, Pia; Noll, Alexander; Schulze, Renate; Ehlert, Ulrike; Frey, Karl; Fischer, Joachim E

    2003-08-01

    Adverse work characteristics and poor social support have been associated with an increased risk for cardiovascular disease and other adverse health outcomes in otherwise apparently healthy adults. We undertook a cross-sectional study to evaluate the relationship between objective health status and work characteristics in industrial workers in Germany. Volunteers (n=324) were recruited from a representative random sample (n=537) of employees of an airplane manufacturing plant. Psychosocial work characteristics were assessed by the 52-item, 13-subscale salutogenetic subjective work analysis (SALSA) questionnaire, which assesses potentially salutogenic and pathogenic conditions. Factor analysis revealed three factors: decision latitude, job demands and social support. Biological health status was determined by the revised allostatic load score with 14 components: body-mass index, waist-to-hip ratio; systolic and diastolic blood pressure; plasma levels of C-reactive protein (CRP), tumor-necrosis factor-alpha, HDL, cholesterol, dehydroepiandrosterone sulfate; glycosylated hemoglobin; urinary cortisol, epinephrine, norepinephrine, and albumin. Score points were given for values in the high-risk quartile (maximum=14). General linear models revealed that older individuals and men had significantly higher allostatic load scores than younger participants or women. Of the SALSA factors, only job demands related significantly to allostatic load. The effect of demands was stronger in older individuals. Post-hoc analysis showed possible positive associations between high job demands and blood pressure or CRP, and between low social support and nocturnal excretion of cortisol or plasma levels of CRP. We conclude that this cross-sectional study on industrial employees found a weak association between a health summary score based on objective medical data and self-reported adverse work characteristics. PMID:12821013

  4. Allostatic Load and Preterm Birth

    PubMed Central

    Olson, David M.; Severson, Emily M.; Verstraeten, Barbara S. E.; Ng, Jane W. Y.; McCreary, J. Keiko; Metz, Gerlinde A. S.

    2015-01-01

    Preterm birth is a universal health problem that is one of the largest unmet medical needs contributing to the global burden of disease. Adding to its complexity is that there are no means to predict who is at risk when pregnancy begins or when women will actually deliver. Until these problems are addressed, there will be no interventions to reduce the risk because those who should be treated will not be known. Considerable evidence now exists that chronic life, generational or accumulated stress is a risk factor for preterm delivery in animal models and in women. This wear and tear on the body and mind is called allostatic load. This review explores the evidence that chronic stress contributes to preterm birth and other adverse pregnancy outcomes in animal and human studies. It explores how allostatic load can be used to, firstly, model stress and preterm birth in animal models and, secondly, how it can be used to develop a predictive model to assess relative risk among women in early pregnancy. Once care providers know who is in the highest risk group, interventions can be developed and applied to mitigate their risk. PMID:26694355

  5. Allostatic Load and Health Status of African Americans and Whites

    ERIC Educational Resources Information Center

    Deuster, Patricia A.; Kim-Dorner, Su Jong; Remaley, Alan T.; Poth, Merrily

    2011-01-01

    Objectives: To compare health risks in 84 healthy African American and 45 white men and women after calculating allostatic load (AL) from biologic, psychosocial, and behavioral measures. Methods: Participants (18-45 years) ranging in weight from normal to obese and without hypertension or diabetes. Fitness, body fat, CRP, mood, social support,…

  6. Allostasis and allostatic load: implications for neuropsychopharmacology.

    PubMed

    McEwen, B S

    2000-02-01

    The primary hormonal mediators of the stress response, glucocorticoids and catecholamines, have both protective and damaging effects on the body. In the short run, they are essential for adaptation, maintenance of homeostasis, and survival (allostasis). Yet, over longer time intervals, they exact a cost (allostatic load) that can accelerate disease processes. The concepts of allostasis and allostatic load center around the brain as interpreter and responder to environmental challenges and as a target of those challenges. In anxiety disorders, depressive illness, hostile and aggressive states, substance abuse, and post-traumatic stress disorder (PTSD), allostatic load takes the form of chemical imbalances as well as perturbations in the diurnal rhythm, and, in some cases, atrophy of brain structures. In addition, growing evidence indicates that depressive illness and hostility are both associated with cardiovascular disease (CVD) and other systemic disorders. A major risk factor for these conditions is early childhood experiences of abuse and neglect that increase allostatic load later in life and lead individuals into social isolation, hostility, depression, and conditions like extreme obesity and CVD. Animal models support the notion of lifelong influences of early experience on stress hormone reactivity. Whereas, depression and childhood abuse and neglect tend to be more prevalent in individuals at the lower end of the socioeconomic ladder, cardiovascular and other diseases follow a gradient across the full range of socioeconomic status (SES). An SES gradient is also evident for measures of allostatic load. Wide-ranging SES gradients have also been described for substance abuse and affective and anxiety disorders as a function of education. These aspects are discussed as important, emerging public health issues where the brain plays a key role. PMID:10649824

  7. Childhood Maltreatment Predicts Allostatic Load in Adulthood

    PubMed Central

    Widom, Cathy Spatz; Horan, Jacqueline; Brzustowicz, Linda

    2015-01-01

    Childhood maltreatment has been linked to numerous negative health outcomes. However, few studies have examined mediating processes using longitudinal designs or objectively measured biological data. This study sought to determine whether child abuse and neglect predicts allostatic load (a composite indicator of accumulated stress-induced biological risk) and to examine potential mediators. Using a prospective cohort design, children (ages 0-11) with documented cases of abuse and neglect were matched with non-maltreated children and followed up into adulthood with in-person interviews and a medical status exam (mean age 41). Allostatic load was assessed with nine physical health indicators. Child abuse and neglect predicted allostatic load, controlling for age, sex, and race. The direct effect of child abuse and neglect persisted despite the introduction of potential mediators of internalizing and externalizing problems in adolescence and social support and risky lifestyle in middle adulthood. These findings reveal the long-term impact of childhood abuse and neglect on physical health over 30 years later. PMID:25700779

  8. Cumulative Stress Pathophysiology in Schizophrenia as Indexed by Allostatic Load

    PubMed Central

    Nugent, Katie L.; Chiappelli, Joshua; Rowland, Laura M.; Hong, L. Elliot

    2015-01-01

    Background The etiopathophysiology of schizophrenia has long been linked to stress and the influence of stress is important in all stages of the illness. Previous examinations of perceived stress and acute stress responses may not capture this longitudinal stress pathophysiology. We hypothesized that the cumulative negative effects of stress, indexed by allostatic load (AL), would be elevated in schizophrenia, and that the AL paradigm would be relevant to our understanding of pathophysiology in schizophrenia. Methods We assessed allostatic load in 30 patients with schizophrenia (SZ; mean age=33; 17 males) and 20 healthy controls (HC; mean age=35; 12 males) using 13cardiovascular, metabolic, neuroendocrine and immune biomarkers. Participants’ perceived stress over the past month; functional capacity and psychiatric symptoms were also measured. Results Controlling for age, SZ had significantly higher AL as compared to HC (p=0.007). Greater AL was present in both early course and chronic SZ, and was associated with reduced functional capacity (p=0.006) and more psychotic symptoms (p=0.048) in SZ. Current level of perceived stress was not significantly elevated in SZ or associated with AL in either group. Conclusions The higher AL found in SZ may reflect increased bodily “wear and tear”, possibly caused by more chronic stress exposure or maladaptive responses to stress over time, although additional research is required to differentiate these causes. The higher AL is similarly present in early and chronic SZ, suggesting primary maladaptive stress physiology rather than secondary effects from medications or chronic illness. PMID:26142568

  9. Allostatic load: a mechanism of socioeconomic health disparities?

    PubMed

    Szanton, Sarah L; Gill, Jessica M; Allen, Jerilyn K

    2005-07-01

    Although research on health disparities has been prioritized by the National Institutes of Health, the Institute of Medicine, and Healthy People 2010, little has been published that examines the biology underlying health disparities. Allostatic load is a multisystem construct theorized to quantify stress-induced biological risk. Differences in allostatic load may reflect differences in stress exposure and thus provide a mechanistic link to understanding health disparities. The purpose of this systematic review is to examine the construct of allostatic load and the published studies that employ it in an effort to understand whether the construct can be useful in quantifying health disparities. The published literature demonstrates that allostatic load is elevated in those of low socioeconomic status (SES) as compared to those of high SES. The reviewed articles vary in the justification for inclusion of variables. Recommendations for future research are made in the contexts of measurement, methodology, and racial composition of participants.

  10. Sibling competition and hunger increase allostatic load in spotted hyaenas.

    PubMed

    Benhaiem, Sarah; Hofer, Heribert; Dehnhard, Martin; Helms, Janine; East, Marion L

    2013-06-23

    Allostatis is the process of maintaining homeostatis through behavioural or physiological responses to challenges, and its cumulative energetic cost is termed allostatic load. The allostatic load hypothesis predicts that hunger and the mechanisms that establish and maintain social dominance should have a strong impact on allostatic load. In spotted hyaenas, dominance between twin siblings emerges during intense early competition for maternal milk and involves trained winner/loser effects. Conflict over access to teats declines with age as behavioural dominance conventions are established. In young litters, the allostatic load of subordinates measured in terms of faecal glucocorticoid metabolite concentrations (fGMCs) should be higher than that of dominants. When low milk provisioning threatens survival, hungry subordinates are more assertive, particularly when competing against a dominant sister. Dominants challenged by assertive subordinates should have allostatic loads and fGMCs above those of dominants with subordinates that adhere to dominance conventions. We show that in young litters, subordinates had significantly higher fGMCs than dominants, and dominant sisters had significantly higher fGMCs than dominant brothers. When hungry, both dominants and subordinates had significantly higher fGMCs than when fed. Our results provide evidence that hunger and sibling competition affect allostatic load in spotted hyaenas.

  11. Sibling competition and hunger increase allostatic load in spotted hyaenas.

    PubMed

    Benhaiem, Sarah; Hofer, Heribert; Dehnhard, Martin; Helms, Janine; East, Marion L

    2013-06-23

    Allostatis is the process of maintaining homeostatis through behavioural or physiological responses to challenges, and its cumulative energetic cost is termed allostatic load. The allostatic load hypothesis predicts that hunger and the mechanisms that establish and maintain social dominance should have a strong impact on allostatic load. In spotted hyaenas, dominance between twin siblings emerges during intense early competition for maternal milk and involves trained winner/loser effects. Conflict over access to teats declines with age as behavioural dominance conventions are established. In young litters, the allostatic load of subordinates measured in terms of faecal glucocorticoid metabolite concentrations (fGMCs) should be higher than that of dominants. When low milk provisioning threatens survival, hungry subordinates are more assertive, particularly when competing against a dominant sister. Dominants challenged by assertive subordinates should have allostatic loads and fGMCs above those of dominants with subordinates that adhere to dominance conventions. We show that in young litters, subordinates had significantly higher fGMCs than dominants, and dominant sisters had significantly higher fGMCs than dominant brothers. When hungry, both dominants and subordinates had significantly higher fGMCs than when fed. Our results provide evidence that hunger and sibling competition affect allostatic load in spotted hyaenas. PMID:23616643

  12. Stress, Allostatic Load, Catecholamines, and Other Neurotransmitters in Neurodegenerative Diseases

    PubMed Central

    2016-01-01

    As populations age, the prevalence of geriatric neurodegenerative diseases will increase. These diseases generally are multifactorial, arising from complex interactions among genes, environment, concurrent morbidities, treatments, and time. This essay provides a concept for the pathogenesis of Lewy body diseases such as Parkinson disease, by considering them in the context of allostasis and allostatic load. Allostasis reflects active, adaptive processes that maintain apparent steady states, via multiple, interacting effectors regulated by homeostatic comparators—“homeostats.” Stress can be defined as a condition or state in which a sensed discrepancy between afferent information and a setpoint for response leads to activation of effectors, reducing the discrepancy. “Allostatic load” refers to the consequences of sustained or repeated activation of mediators of allostasis. From the analogy of an idling car, the revolutions per minute of the engine can be maintained at any of a variety of levels (allostatic states). Just as allostatic load (cumulative wear and tear) reflects design and manufacturing variations, byproducts of combustion, and time, eventually leading to engine breakdown, allostatic load in catecholaminergic neurons might eventually lead to Lewy body diseases. Central to the argument is that catecholaminergic neurons leak vesicular contents into the cytoplasm continuously during life and that catecholamines in the neuronal cytoplasm are autotoxic. These neurons therefore depend on vesicular sequestration to limit autotoxicity of cytosolic transmitter. Parkinson disease might be a disease of the elderly because of allostatic load, which depends on genetic predispositions, environmental exposures, repeated stress-related catecholamine release, and time. PMID:22297542

  13. Children's Negative Emotionality Combined with Poor Self-Regulation Affects Allostatic Load in Adolescence

    ERIC Educational Resources Information Center

    Dich, Nadya; Doan, Stacey; Evans, Gary

    2015-01-01

    The present study examined the concurrent and prospective, longitudinal effects of childhood negative emotionality and self-regulation on allostatic load (AL), a physiological indicator of chronic stress. We hypothesized that negative emotionality in combination with poor self-regulation would predict elevated AL. Mothers reported on children's…

  14. Purpose in Life Predicts Allostatic Load Ten Years Later

    PubMed Central

    Zilioli, Samuele; Slatcher, Richard B.; Ong, Anthony D.; Gruenewald, Tara

    2015-01-01

    Objective Living a purposeful life is associated with better mental and physical health, including longevity. Accumulating evidence shows that these associations might be explained by the association between life purpose and regulation of physiological systems involved in the stress response. The aim of this study was to investigate the prospective associations between life purpose and allostatic load over a 10-year period. Methods Analyses were conducted using data from the Midlife in the United States (MIDUS) survey. Assessment of life purpose, psychological covariates and demographics were obtained at baseline, while biomarkers of allostatic load were assessed at the 10-year follow-up. Results We found that greater life purpose predicted lower levels of allostatic load at follow-up, even when controlling for other aspects of psychological well-being potentially associated with allostatic load. Further, life purpose was also a strong predictor of individual differences in self-health locus of control—i.e., beliefs about how much influence individuals can exert on their own health—which, in turn, partially mediated the association between purpose and allostatic load. Although life purpose was also negatively linked to other-health locus of control —i.e., the extent to which individuals believe their health is controlled by others/chance —this association did not mediate the impact of life purpose on allostatic load. Conclusion The current study provides the first empirical evidence for the long-term physiological correlates of life purpose and supports the hypothesis that self-health locus of control acts as one proximal psychological mechanism through which life purpose may be linked to positive biological outcomes. PMID:26526322

  15. Neighborhood features and physiological risk: An examination of allostatic load.

    PubMed

    Robinette, Jennifer W; Charles, Susan T; Almeida, David M; Gruenewald, Tara L

    2016-09-01

    Poor neighborhoods may represent a situation of chronic stress, and may therefore be associated with health-related correlates of stress. We examined whether lower neighborhood income would relate to higher allostatic load, or physiological well-being, through psychological, affective, and behavioral pathways. Using data from the Biomarker Project of the Midlife in the United States (MIDUS) study and the 2000 Census, we demonstrated that people living in lower income neighborhoods have higher allostatic load net of individual income. Moreover, findings indicate that this relation is partially accounted for by anxious arousal symptoms, fast food consumption, smoking, and exercise habits. PMID:27583527

  16. Allostatic Load: Single Parents, Stress-Related Health Issues, and Social Care

    ERIC Educational Resources Information Center

    Johner, Randy L.

    2007-01-01

    This article explores the possible relationships between allostatic load (AL) and stress-related health issues in the low-income single-parent population, using both a population health perspective (PHP) and a biological framework. A PHP identifies associations among such factors as gender, income, employment, and social support and their…

  17. Perceived Discrimination among African American Adolescents and Allostatic Load: A Longitudinal Analysis with Buffering Effects

    ERIC Educational Resources Information Center

    Brody, Gene H.; Lei, Man-Kit; Chae, David H.; Yu, Tianyi; Kogan, Steven M.; Beach, Steven R. H.

    2014-01-01

    This study was designed to examine the prospective relations of perceived racial discrimination with allostatic load (AL), along with a possible buffer of the association. A sample of 331 African Americans in the rural South provided assessments of perceived discrimination from ages 16 to 18 years. When youth were 18 years, caregivers reported…

  18. Measuring allostatic load in the workforce: a systematic review

    PubMed Central

    MAUSS, Daniel; LI, Jian; SCHMIDT, Burkhard; ANGERER, Peter; JARCZOK, Marc N.

    2014-01-01

    The Allostatic Load Index (ALI) has been used to establish associations between stress and health-related outcomes. This review summarizes the measurement and methodological challenges of allostatic load in occupational settings. Databases of Medline, PubPsych, and Cochrane were searched to systematically explore studies measuring ALI in working adults following the PRISMA statement. Study characteristics, biomarkers and methods were tabulated. Methodological quality was evaluated using a standardized checklist. Sixteen articles (2003–2013) met the inclusion criteria, with a total of 39 (range 6–17) different variables used to calculate ALI. Substantial heterogeneity was observed in the number and type of biomarkers used, the analytic techniques applied and study quality. Particularly, primary mediators were not regularly included in ALI calculation. Consensus on methods to measure ALI in working populations is limited. Research should include longitudinal studies using multi-systemic variables to measure employees at risk for biological wear and tear. PMID:25224337

  19. Allostatic and Environmental Load in Toddlers Predicts Anxiety in Preschool and Kindergarten

    PubMed Central

    Buss, Kristin A.; Davis, Elizabeth L.; Kiel, Elizabeth J.

    2010-01-01

    Psychobiological models of allostatic load have delineated the effects of multiple processes that contribute to risk for psychopathology. This approach has been fruitful, but the interactive contributions of allostatic and environmental load remain understudied in early childhood. Because this developmental period encompasses the emergence of internalizing problems and biological sensitivity to early experiences, this is an important time to examine this process. In two studies, we examined allostatic and environmental load and links to subsequent internalizing and externalizing problems. Study 1 examined relations between load indices and maladjustment, concurrently and at multiple times between age 2 and kindergarten; Study 2 added more comprehensive risk indices in a sample following a group of highly fearful toddlers from 2 to 3 years of age. Results from both studies showed that increased allostatic load related to internalizing problems as environmental risk also increased. Study 2 additionally showed that fearfulness interacted with allostatic and environmental load indices to predict greater anxiety among the fearful children who had high levels of allostatic and environmental load. Taken together, findings support a model of risk for internalizing characterized by the interaction of biological and environmental stressors, and demonstrate the importance of considering individual differences and environmental context in applying models of allostatic load to developmental change in early childhood. PMID:22018082

  20. Stressors Among Latino Day Laborers A Pilot Study Examining Allostatic Load

    PubMed Central

    de Castro, A. B.; Voss, Joachim G.; Ruppin, Ayelet; Dominguez, Carlos F.; Seixas, Noah S.

    2010-01-01

    This pilot study evaluated the feasibility of conducting a research project focused on stressors and allostatic load (AL) among day laborers. A total of 30 Latino men were recruited from CASA Latina. a worker center in Seattle. Participants completed an interview and researchers measured six indicators of AL (body mass index, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, C-reactive protein, and cortisol). Percentages and mean scores were calculated for several self-reported stressors in work, economic, and social contexts and were compared between low and high AL groups. Overall, participants with high AL reported experiencing more stressors than those with low AL. Additionally, those with high AL generally reported being less healthy both physically and mentally. Findings suggest that Latino day laborers experience stressors that place them at risk for high AL. Also, a study of this nature is possible, but must be conducted with trust and collaboration between researchers and community partners. PMID:20507008

  1. Stress, Place, and Allostatic Load Among Mexican Immigrant Farmworkers in Oregon.

    PubMed

    McClure, Heather H; Josh Snodgrass, J; Martinez, Charles R; Squires, Erica C; Jiménez, Roberto A; Isiordia, Laura E; Eddy, J Mark; McDade, Thomas W; Small, Jeon

    2015-10-01

    Cumulative exposure to chronic stressors has been shown to contribute to immigrants' deteriorating health with more time in US residence. Few studies, however, have examined links among common psychosocial stressors for immigrants (e.g., acculturation-related) and contexts of immigrant settlement for physical health. The study investigated relationships among social stressors, stress buffers (e.g., family support), and allostatic load (AL)--a summary measure of physiological "wear and tear"--among 126 adult Mexican immigrant farm workers. Analyses examined social contributors to AL in two locales: (1) White, English-speaking majority sites, and (2) a Mexican immigrant enclave. Our six-point AL scale incorporated immune, cardiovascular, and metabolic measures. Among men and women, older age predicted higher AL. Among women, lower family support related to higher AL in White majority communities only. Findings suggest that Latino immigrants' cumulative experiences in the US significantly compromise their health, with important differences by community context. PMID:25724150

  2. Perceived discrimination among African American adolescents and allostatic load: a longitudinal analysis with buffering effects.

    PubMed

    Brody, Gene H; Lei, Man-Kit; Chae, David H; Yu, Tianyi; Kogan, Steven M; Beach, Steven R H

    2014-01-01

    This study was designed to examine the prospective relations of perceived racial discrimination with allostatic load (AL), along with a possible buffer of the association. A sample of 331 African Americans in the rural South provided assessments of perceived discrimination from ages 16 to 18 years. When youth were 18 years, caregivers reported parental emotional support and youth assessed peer emotional support. AL and potential confounder variables were assessed when youth were 20. Latent growth mixture modeling identified two perceived discrimination classes: high and stable, and low and increasing. Adolescents in the high and stable class evinced heightened AL even with confounder variables controlled. The racial discrimination to AL link was not significant for young adults who received high emotional support.

  3. Perceived discrimination among African American adolescents and allostatic load: a longitudinal analysis with buffering effects.

    PubMed

    Brody, Gene H; Lei, Man-Kit; Chae, David H; Yu, Tianyi; Kogan, Steven M; Beach, Steven R H

    2014-01-01

    This study was designed to examine the prospective relations of perceived racial discrimination with allostatic load (AL), along with a possible buffer of the association. A sample of 331 African Americans in the rural South provided assessments of perceived discrimination from ages 16 to 18 years. When youth were 18 years, caregivers reported parental emotional support and youth assessed peer emotional support. AL and potential confounder variables were assessed when youth were 20. Latent growth mixture modeling identified two perceived discrimination classes: high and stable, and low and increasing. Adolescents in the high and stable class evinced heightened AL even with confounder variables controlled. The racial discrimination to AL link was not significant for young adults who received high emotional support. PMID:24673162

  4. The role of education in explaining racial/ethnic allostatic load differentials in the United States.

    PubMed

    Howard, Jeffrey T; Sparks, P Johnelle

    2015-01-01

    This study expands on earlier findings of racial/ethnic and education-allostatic load associations by assessing whether racial/ethnic differences in allostatic load persist across all levels of educational attainment. This study used data from four recent waves of the National Health and Nutrition Survey (NHANES). Results from this study suggest that allostatic load differs significantly by race/ethnicity and educational attainment overall, but that the race/ethnicity association is not consistent across education level. Analysis of interactions and education-stratified models suggest that allostatic load levels do not differ by race/ethnicity for individuals with low education; rather, the largest allostatic load differentials for Mexican Americans (p < .01) and non-Hispanic blacks (p < .001) are observed for individuals with a college degree or more. These findings add to the growing evidence that differences in socioeconomic opportunities by race/ethnicity are likely a consequence of differential returns to education, which contribute to higher stress burdens among minorities compared to non-Hispanic whites.

  5. Obesity: the allostatic load of weight loss dieting.

    PubMed

    Tremblay, Angelo; Chaput, Jean-Philippe

    2012-04-12

    The obesity epidemic that is prevailing in most countries of the world is generally attributed to the increased amount of opportunities to be in positive energy balance in a context of modernity. This obviously refers not only to sedentariness and unhealthy eating that may dominate life habits of many individuals but also to unsuspected non-caloric factors which produce discrete allostatic changes in the body. In this paper, the focus is put on the impact of some of these factors with the preoccupation to document the allostatic burden of weight loss. Thus, beyond the fact that modernity favors opportunities to eat much and not to be active, the proposed conceptual integration leads to the conclusion that a modern lifestyle makes weight loss more difficult for obese individuals. In addition to the natural effects of weight loss favoring resistance to lose fat, a lifestyle promoting shorter sleep duration and more cognitive demand produces allostatic changes that may interfere with weight loss. The case of persistent organic pollutants (POPs) is also discussed as an example of the potential detrimental effects of a contaminated environment on metabolic processes involved in the control of energy expenditure. Taken together, these observations suggest that weight loss is more than ever a search for compromise between its metabolic benefits and its allostatic effects promoting body weight regain.

  6. Allostatic load model associated with indoor environmental quality and sick building syndrome among office workers.

    PubMed

    Jung, Chien-Cheng; Liang, Hsiu-Hao; Lee, Hui-Ling; Hsu, Nai-Yun; Su, Huey-Jen

    2014-01-01

    This study investigates whether indoor environmental quality (IEQ) influences allostatic load (AL) and whether AL can be a predictor for sick building syndrome (SBS). We also assessed and compared the associations between AL and SBS versus 8-hydroxydeoxyguanosine (8-OHdG) and SBS. A total of 115 office workers from 21 offices completed self-reported SBS questionnaires, and provided 11 biomarkers for their AL. Multiple linear regressions and logistic regression analysis were applied to examine the correlations between IEQ and AL or 8-OHdG and between AL or 8-OHdG and SBS, respectively. Our data revealed that the neuroendocrine system was correlated with CO2, the difference between indoor and outdoor CO2 levels (dCO2), and the indoor-outdoor ratio of CO2 (CO2 I/O). Metabolic system effects were associated with illumination. The relationships between illumination, CO2, dCO2, CO2 I/O and 8-OHdG were consistent with those and AL in specific systems. Furthermore, we found that risks for SBS syndromes were related with neuroendocrine and metabolic system of the AL. 8-OHdG was associated with eye dryness or irritation, eye tiredness and vomiting. We conclude that IEQ significantly influences AL and that AL can be a predictor for reporting SBS with information on system-specific effects. PMID:24759685

  7. Allostatic Load Model Associated with Indoor Environmental Quality and Sick Building Syndrome among Office Workers

    PubMed Central

    Jung, Chien-Cheng; Liang, Hsiu-Hao; Lee, Hui-Ling; Hsu, Nai-Yun; Su, Huey-Jen

    2014-01-01

    This study investigates whether indoor environmental quality (IEQ) influences allostatic load (AL) and whether AL can be a predictor for sick building syndrome (SBS). We also assessed and compared the associations between AL and SBS versus 8-hydroxydeoxyguanosine (8-OHdG) and SBS. A total of 115 office workers from 21 offices completed self-reported SBS questionnaires, and provided 11 biomarkers for their AL. Multiple linear regressions and logistic regression analysis were applied to examine the correlations between IEQ and AL or 8-OHdG and between AL or 8-OHdG and SBS, respectively. Our data revealed that the neuroendocrine system was correlated with CO2, the difference between indoor and outdoor CO2 levels (dCO2), and the indoor-outdoor ratio of CO2 (CO2 I/O). Metabolic system effects were associated with illumination. The relationships between illumination, CO2, dCO2, CO2 I/O and 8-OHdG were consistent with those and AL in specific systems. Furthermore, we found that risks for SBS syndromes were related with neuroendocrine and metabolic system of the AL. 8-OHdG was associated with eye dryness or irritation, eye tiredness and vomiting. We conclude that IEQ significantly influences AL and that AL can be a predictor for reporting SBS with information on system-specific effects. PMID:24759685

  8. Childhood poverty and young adults' allostatic load: the mediating role of childhood cumulative risk exposure.

    PubMed

    Evans, Gary W; Kim, Pilyoung

    2012-09-01

    Childhood poverty is linked to a host of physical and psychological disorders during childhood and later in life. In the study reported here, we showed that the proportion of childhood spent in poverty from birth to age 9 was linked to elevated allostatic load, a marker of chronic physiological stress, in 17-year-olds. Furthermore, this prospective longitudinal relationship was mediated by cumulative risk exposure at age 13. The greater the duration of early life spent in poverty, the greater the exposure to cumulative risk. This, in turn, leads to elevated allostatic load. Multiple psychological, biological, and neurological pathways likely account for the social patterning of psychological and physical disease.

  9. Allostatic load in parents of children with developmental disorders: moderating influence of positive affect.

    PubMed

    Song, Jieun; Mailick, Marsha R; Ryff, Carol D; Coe, Christopher L; Greenberg, Jan S; Hong, Jinkuk

    2014-02-01

    This study examines whether parents of children with developmental disorders are at risk of elevated allostatic load relative to control parents and whether positive affect moderates difference in risk. In all, 38 parents of children with developmental disorders and 38 matched comparison parents were analyzed. Regression analyses revealed a significant interaction between parent status and positive affect: parents of children with developmental disorders had lower allostatic load when they had higher positive affect, whereas no such association was evident for comparison parents. The findings suggest that promoting greater positive affect may lower health risks among parents of children with developmental disorders.

  10. Rearing history and allostatic load in adult western lowland gorillas (Gorilla gorilla gorilla) in human care.

    PubMed

    Edes, Ashley N; Wolfe, Barbara A; Crews, Douglas E

    2016-01-01

    Disrupted rearing history is a psychological and physical stressor for nonhuman primates, potentially resulting in multiple behavioral and physiological changes. As a chronic, soma-wide stressor, altered rearing may be best assessed using a holistic tool such as allostatic load (AL). In humans, AL estimates outcomes of lifetime stress-induced damage. We predicted mother-reared gorillas would have lower AL than nursery-reared and wild-caught conspecifics. We estimated AL for 27 gorillas housed at the Columbus Zoo and Aquarium between 1956 and 2014. AL estimates were calculated using biomarkers obtained during previous anesthetic events. Biomarkers in the high-risk quartile were counted toward a gorilla's AL. Rearing history was categorized as mother-reared, nursery-reared, and wild-caught. Using ANCOVA, rearing history and AL are significantly associated when age and sex are entered as covariates. Wild-caught gorillas have significantly higher AL than mother-reared gorillas. Neither wild-caught nor mother-reared gorillas are significantly different from nursery-reared gorillas. When examined by sex, males of all rearing histories have significantly lower AL than females. We suggest males face few stressors in human care and ill effects of rearing history do not follow. Wild-caught females have significantly higher AL than mother-reared females, but neither is significantly different from nursery-reared females. Combined with our previous work on AL in this group, wherein females had twofold higher AL than males, we suggest females in human care face more stressors than males. Disrupted rearing history may exacerbate effects of these stressors. Providing opportunities for females to choose their distance from males may help reduce their AL.

  11. Rearing history and allostatic load in adult western lowland gorillas (Gorilla gorilla gorilla) in human care.

    PubMed

    Edes, Ashley N; Wolfe, Barbara A; Crews, Douglas E

    2016-01-01

    Disrupted rearing history is a psychological and physical stressor for nonhuman primates, potentially resulting in multiple behavioral and physiological changes. As a chronic, soma-wide stressor, altered rearing may be best assessed using a holistic tool such as allostatic load (AL). In humans, AL estimates outcomes of lifetime stress-induced damage. We predicted mother-reared gorillas would have lower AL than nursery-reared and wild-caught conspecifics. We estimated AL for 27 gorillas housed at the Columbus Zoo and Aquarium between 1956 and 2014. AL estimates were calculated using biomarkers obtained during previous anesthetic events. Biomarkers in the high-risk quartile were counted toward a gorilla's AL. Rearing history was categorized as mother-reared, nursery-reared, and wild-caught. Using ANCOVA, rearing history and AL are significantly associated when age and sex are entered as covariates. Wild-caught gorillas have significantly higher AL than mother-reared gorillas. Neither wild-caught nor mother-reared gorillas are significantly different from nursery-reared gorillas. When examined by sex, males of all rearing histories have significantly lower AL than females. We suggest males face few stressors in human care and ill effects of rearing history do not follow. Wild-caught females have significantly higher AL than mother-reared females, but neither is significantly different from nursery-reared females. Combined with our previous work on AL in this group, wherein females had twofold higher AL than males, we suggest females in human care face more stressors than males. Disrupted rearing history may exacerbate effects of these stressors. Providing opportunities for females to choose their distance from males may help reduce their AL. PMID:26881840

  12. Allostatic Load Assessment for Early Detection of Stress in the Workplace in Egypt

    PubMed Central

    Ali, Ola Sayed; Badawy, Nadia; Rizk, Sanaa; Gomaa, Hend; Saleh, Mai Sabry

    2016-01-01

    AIM: Workplace stress is hazardous for its harmful impact on employees’ health and organizational productivity. The aim of the study is to apply the Allostatic Load Index (ALI) which is a multi-component measure for health risk assessment and early detection of stress among workers in Egypt. METHODS: Sixty-two working adults randomly selected from two different working environments in Egypt were included in the study. Participants completed a self-reported questionnaire for socio-demographic and work variables. Andrews and Withey test for Job Satisfaction was filled and 3 ml blood samples were collected. Markers assessed for Allostatic Load were serum cortisol, c-reactive protein, dehydroepiandrosterone-sulphate, total thyroxine, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, total cholesterol to high-density lipoprotein ratio, systolic and diastolic blood pressures, waist to hip ratio and body mass index. The risk quartile method was used for calculation of ALI. ALI value of four or more indicates high Allostatic Load. RESULTS: Job satisfaction scale defined about a quarter of the study population (24%) to be dissatisfied with Allostatic Load of 2.4 as the mean value. Population percentage with ALI ≥4 reached 12.9% with 100% of them females. A significant association was found between Allostatic Load of primary mediators and age, the presence of chronic diseases, place of work and female gender. CONCLUSION: Female gender and the old age of the Egyptian workforce under study are at higher risk of chronic diseases. Using an alternative way -for example, the cut-point method- instead of the risk quartiles for dichotomization of markers used in ALI calculation could be more precise for early detection of stress among healthy individuals. PMID:27703581

  13. Allostatic load is associated with chronic conditions in the Boston Puerto Rican Health Study.

    PubMed

    Mattei, Josiemer; Demissie, Serkalem; Falcon, Luis M; Ordovas, Jose M; Tucker, Katherine

    2010-06-01

    Puerto Ricans living in the United States mainland present multiple disparities in prevalence of chronic diseases, relative to other racial and ethnic groups. Allostatic load (AL), or the cumulative wear and tear of physiological responses to stressors such as major life events, social and environmental burden, has been proposed as a possible mechanism for the inequalities observed in minority groups, but has not been studied in Puerto Ricans. The aim of this study was to determine the association of AL to six chronic diseases (abdominal obesity, hypertension, diabetes, and self-reported cardiovascular disease (CVD), arthritis and cancer) in Puerto Ricans, and to contrast AL to metabolic syndrome (MetS). Participants of the Boston Puerto Rican Health Study (n=1116, ages 45-75 years) underwent a home-based interview, where questionnaires were completed and biological samples collected. A summary definition of AL was constructed using clinically-defined cutoffs and medication use for 10 physiological parameters in different body systems. Logistic regression models were run to determine associations between AL score and disease status, controlling for age, sex, smoking, alcohol use, physical activity, total fat intake and energy intake. Parallel models were also run with MetS score replacing AL. We found that increasing categories of AL score were significantly associated with abdominal obesity, hypertension, diabetes and self-reported cardiovascular disease (CVD) and arthritis, but not with self-reported cancer. The strength of associations of AL with all conditions, except diabetes and cancer, was similar to or larger than those of MetS score. In conclusion, Puerto Rican older adults experienced physiological dysregulation that was associated with increased odds of chronic conditions. AL was more strongly associated with most conditions, compared to MetS, suggesting that this cumulative measure may be a better predictor of disease. These results have prospective

  14. A multimethodological analysis of cumulative risk and allostatic load among rural children.

    PubMed

    Evans, Gary W

    2003-09-01

    This study merged two theoretical constructs: cumulative risk and allostatic load. Physical (crowding, noise, housing quality) and psychosocial (child separation, turmoil, violence) aspects of the home environment and personal characteristics (poverty, single parenthood, maternal highschool dropout status) were modeled in a cumulative risk heuristic. Elevated cumulative risk was associated with heightened cardiovascular and neuroendocrine parameters, increased deposition of body fat, and a higher summary index of total allostatic load. Previous findings that children who face more cumulative risk have greater psychological distress were replicated among a sample of rural children and shown to generalize to lower perceptions of self-worth. Prior cumulative risk research was further extended through demonstration of self-regulatory behavior problems and elevated learned helplessness. PMID:12952404

  15. From Childhood Maltreatment to Allostatic Load in Adulthood: The Role of Social Support.

    PubMed

    Horan, Jacqueline M; Widom, Cathy S

    2015-11-01

    Although previous research has documented that social support acts as a protective factor for individuals exposed to trauma, most research relies on assessments of social support at one point in time. The present study used data from a prospective cohort design study to examine the stability of social support from childhood through middle adulthood in individuals with documented histories of childhood abuse and neglect and matched controls (aged 0-11) and assessed the impact of social support on allostatic load, a composite measure of physiological stress response assessed through blood tests and physical measurements, in middle adulthood. Maltreated children are more likely to have unstable social support across the life span, compared to matched controls. Social support across the life span partially mediated the relationship between child maltreatment and allostatic load in adulthood, although there were differences by race and sex. These findings have implications for interventions to prevent the negative consequences of child maltreatment.

  16. Cumulative Neighborhood Risk of Psychosocial Stress and Allostatic Load in Adolescents

    PubMed Central

    Theall, Katherine P.; Drury, Stacy S.; Shirtcliff, Elizabeth A.

    2012-01-01

    The authors examined the impact of cumulative neighborhood risk of psychosocial stress on allostatic load (AL) among adolescents as a mechanism through which life stress, including neighborhood conditions, may affect health and health inequities. They conducted multilevel analyses, weighted for sampling and propensity score-matched, among adolescents aged 12–20 years in the National Health and Nutrition Examination Survey (1999–2006). Individuals (first level, n = 11,886) were nested within families/households (second level, n = 6,696) and then census tracts (third level, n = 2,191) for examination of the contextual effect of cumulative neighborhood risk environment on AL. Approximately 35% of adolescents had 2 or more biomarkers of AL. A significant amount of variance in AL was explained at the neighborhood level. The likelihood of having a high AL was approximately 10% higher for adolescents living in medium-cumulative-risk neighborhoods (adjusted odds ratio (OR) = 1.09, 95% confidence interval (CI): 1.08, 1.09), 28% higher for those living in high-risk neighborhoods (adjusted OR = 1.28, 95% CI: 1.27, 1.30), and 69% higher for those living in very-high-risk neighborhoods (adjusted OR = 1.69, 95% CI: 1.68, 1.70) as compared with adolescents living in low-risk areas. Effect modification was observed by both individual- and neighborhood-level sociodemographic factors. These findings offer support for the hypothesis that neighborhood risks may culminate in a range of biologically mediated negative health outcomes detectable in adolescents. PMID:23035140

  17. Child Maltreatment and Allostatic Load: Consequences for Physical and Mental Health in Children from Low-Income Families

    PubMed Central

    Rogosch, Fred A.; Dackis, Melissa N.; Cicchetti, Dante

    2012-01-01

    Child maltreatment and biomarkers of allostatic load were investigated in relation to child health problems and psychological symptomatology. Participants attended a summer research day camp and included 137 maltreated and 110 nonmaltreated low-income children, who were aged 8 to 10 years (M = 9.42) and racially and ethnically diverse; 52% were male. Measurements obtained included salivary cortisol and DHEA, body-mass index, waist-hip ratio, and blood pressure; these indicators provided a composite index of allostatic load. Child self-report and camp adult-rater reports of child symptomatology were obtained; mothers provided information on health problems. The results indicated that higher allostatic load and child maltreatment status independently predicted poorer health outcomes and greater behavior problems. Moderation effects indicated that allostatic load was related to somatic complaints, attention problems, and thought problems only among maltreated children. Risks associated with high waist-hip ratio, low morning cortisol, and high morning DHEA also were related to depressive symptoms only for maltreated children. The results support an allostatic load conceptualization of the impact of high environmental stress and child abuse and neglect on child health and behavioral outcomes and have important implications for long-term physical and mental health. PMID:22018084

  18. Understanding behavioral effects of early life stress using the reactive scope and allostatic load models

    PubMed Central

    HOWELL, BRITTANY R.; SANCHEZ, MAR M.

    2015-01-01

    The mechanisms through which early life stress leads to psychopathology are thought to involve allostatic load, the “wear and tear” an organism is subjected to as a consequence of sustained elevated levels of glucocorticoids caused by repeated/prolonged stress activations. The allostatic load model described this phenomenon, but has been criticized as inadequate to explain alterations associated with early adverse experience in some systems, including behavior, which cannot be entirely explained from an energy balance perspective. The reactive scope model has been more recently proposed and focuses less on energy balance and more on dynamic ranges of physiological and behavioral mediators. In this review we examine the mechanisms underlying the behavioral consequences of early life stress in the context of both these models. We focus on adverse experiences that involve mother–infant relationship disruption, and dissect those mechanisms involving maternal care as a regulator of development of neural circuits that control emotional and social behaviors in the offspring. We also discuss the evolutionary purpose of the plasticity in behavioral development, which has a clear adaptive value in a changing environment. PMID:22018078

  19. Interparental Aggression and Children’s Adrenocortical Reactivity: Testing an Evolutionary Model of Allostatic Load

    PubMed Central

    Davies, Patrick T.; Sturge-Apple, Melissa L.; Cicchetti, Dante

    2011-01-01

    Guided by an evolutionary model of allostatic load (Korte, Koolhaas, Wingfield, & McEwen, 2005), this study examined the hypothesis that the association between interparental aggression and subsequent changes in children’s cortisol reactivity to interparental conflict is moderated by their temperamental dispositions. Participants of the multi-method, longitudinal study included 201 two-year-old toddlers and their mothers. These children experienced elevated levels of aggression between parents. Consistent with the theory, the results indicated that interparental aggression predicted greater cortisol reactivity over a one year period for children who exhibited high levels of temperamental inhibition and vigilance. Conversely, for children with bold, aggressive temperamental characteristics, interparental aggression was marginally associated with diminished cortisol reactivity. Further underscoring its implications for allostatic load, increasing cortisol reactivity over the one year span was related to concomitant increases in internalizing symptoms but decreases in attention and hyperactivity difficulties. In supporting the evolutionary conceptualization, these results further supported the relative developmental advantages and costs associated with escalating and dampened cortisol reactivity to interparental conflict. PMID:21756433

  20. Disruption of multisystem responses to stress in type 2 diabetes: Investigating the dynamics of allostatic load

    PubMed Central

    Steptoe, Andrew; Hackett, Ruth A.; Lazzarino, Antonio I.; Bostock, Sophie; La Marca, Roberto; Carvalho, Livia A.; Hamer, Mark

    2014-01-01

    Psychological stress-related processes are thought to contribute to the development and progression of type 2 diabetes, but the biological mechanisms involved are poorly understood. Here, we tested the notion that people with type 2 diabetes experience chronic allostatic load, manifest as dynamic disturbances in reactivity to and recovery from stress across multiple (cardiovascular, neuroendocrine, inflammatory, metabolic) biological systems, coupled with heightened experience of chronic life stress. We carried out an experimental comparison of 140 men and women aged 50–75 y with type 2 diabetes and 280 nondiabetic individuals matched on age, sex, and income. We monitored blood pressure (BP) and heart rate, salivary cortisol, plasma interleukin (IL)-6, and total cholesterol in response to standardized mental stress, and assessed salivary cortisol over the day. People with type 2 diabetes showed impaired poststress recovery in systolic and diastolic BP, heart rate and cholesterol, and blunted stress reactivity in systolic BP, cortisol, cholesterol, and IL-6. Cortisol and IL-6 concentrations were elevated, and cortisol measured over the day was higher in the type 2 diabetes group. Diabetic persons reported greater depressive and hostile symptoms and greater stress experience than did healthy controls. Type 2 diabetes is characterized by disruption of stress-related processes across multiple biological systems and increased exposure to life stress. Chronic allostatic load provides a unifying perspective with implications for etiology and patient management. PMID:25331894

  1. Neighborhood Socioeconomic Context and Change in Allostatic Load Among Older Puerto Ricans: the Boston Puerto Rican Health Study

    PubMed Central

    Osypuk, Theresa L.; Arevalo, Sandra; Tucker, Katherine L.; Falcon, Luis M.

    2015-01-01

    Neighborhood context may influence health and health disparities. However, most studies have been constrained by cross-sectional designs that limit causal inference due to failing to establish temporal order of exposure and disease. We tested the impact of baseline neighborhood context (neighborhood socioeconomic status factor at the block-group level, and relative income of individuals compared to their neighbors) on allostatic load two years later. We leveraged data from the Boston Puerto Rican Health Study, a prospective cohort of aging Puerto Rican adults (aged 45–75 at baseline), with change in AL modeled between baseline and the 2nd wave of follow-up using two-level hierarchical linear regression models. Puerto Rican adults with higher income, relative to their neighbors, exhibited lower AL after two years, after adjusting for NSES, age, gender, individual-level SES, length of residence, and city. After additional control for baseline AL, this association was attenuated to marginal significance. We found no significant association of NSES with AL. Longitudinal designs are an important tool to understand how neighborhood contexts influence health and health disparities. PMID:25706323

  2. Life Events Trajectories, Allostatic Load, and the Moderating Role of Age at Arrival from Puerto Rico to the US Mainland

    PubMed Central

    Arévalo, Sandra P.; Tucker, Katherine L; Falcon, Luis M

    2014-01-01

    Our aim was to examine the effects of trajectories of stressful life events on allostatic load, measured over a two year time period, and to investigate the roles of language acculturation and age at migration in this association, in a sample of Puerto Rican migrants. We used data from the Boston Puerto Rican Health Study; a population-based prospective cohort of older Puerto Ricans recruited between the ages of 45 and 75 years. The Institutional Review Boards at Tufts Medical Center and Northeastern University approved the study. We used latent growth mixture modeling (LGMM) to identify different classes of two-year trajectories of stressful life events; analysis of variance to examine group differences by stress trajectory; and linear regression to test for the modifying effects of age at arrival on the association of stress trajectory with allostatic load at follow-up. In LGMM analysis, we identified three distinct stress trajectories; low, moderate ascending, and high. Unexpectedly, participants in the low stress group had the highest allostatic load at follow-up (F=4.4, p=0.01) relative to the other two groups. Age at arrival had a statistically significant moderating effect on the association. A reported two year period of moderate but repetitive and increasingly bad life events was associated with increases in allostatic load for participants who arrived to the U.S. mainland after the age of 5 years, and was particularly strong for those arriving between 6–11 years, but not for those arriving earlier or later. Results from this study highlight the complex effects of stress during the life course, and point to certain vulnerable periods for immigrant children that could modify long term effects of stress. PMID:25265208

  3. Life-Course Accumulation of Neighborhood Disadvantage and Allostatic Load: Empirical Integration of Three Social Determinants of Health Frameworks

    PubMed Central

    Gustafsson, Per E.; San Sebastian, Miguel; Janlert, Urban; Theorell, Töres; Westerlund, Hugo; Hammarström, Anne

    2014-01-01

    Objectives. We examined if the accumulation of neighborhood disadvantages from adolescence to mid-adulthood were related to allostatic load, a measure of cumulative biological risk, in mid-adulthood, and explored whether this association was similar in women and men. Methods. Data were from the participants in the Northern Swedish Cohort (analytical n = 818) at ages 16, 21, 30, and 43 years in 1981, 1986, 1995, and 2008. Personal living conditions were self-reported at each wave. At age 43 years, 12 biological markers were measured to operationalize allostatic load. Registered data for all residents in the cohort participants’ neighborhoods at each wave were used to construct a cumulative measure of neighborhood disadvantage. Associations were examined in ordinary least-squares regression models. Results. We found that cumulative neighborhood disadvantage between ages 16 and 43 years was related to higher allostatic load at age 43 years after adjusting for personal living conditions in the total sample (B = 0.11; P = .004) and in men (B = 0.16; P = .004), but not in women (B = 0.07; P = .248). Conclusions. Our findings suggested that neighborhood disadvantage acted cumulatively over the life course on biological wear and tear, and exemplified the gains of integrating social determinants of health frameworks. PMID:24625161

  4. Impact of alprazolam in allostatic load and neurocognition of patients with anxiety disorders and chronic stress (GEMA): observational study protocol

    PubMed Central

    Soria, Carlos A; Remedi, Carolina; Núñez, Daniel A; D'Alessio, Luciana; Roldán, Emilio J A

    2015-01-01

    Introduction The allostatic load model explains the additive effects of multiple biological processes that accelerate pathophysiology related to stress, particularly in the central nervous system. Stress-related mental conditions such as anxiety disorders and neuroticism (a well-known stress vulnerability factor), have been linked to disturbances of hypothalamo–pituitary–adrenal with cognitive implications. Nevertheless, there are controversial results in the literature and there is a need to determine the impact of the psychopharmacological treatment on allostatic load parameters and in cognitive functions. Gador study of Estres Modulation by Alprazolam, aims to determine the impact of medication on neurobiochemical variables related to chronic stress, metabolic syndrome, neurocognition and quality of life in patients with anxiety, allostatic load and neuroticism. Methods/analysis In this observational prospective phase IV study, highly sympthomatic patients with anxiety disorders (six or more points in the Hamilton-A scale), neuroticism (more than 18 points in the Neo five personality factor inventory (NEO-FFI) scale), an allostatic load (three positive clinical or biochemical items at Crimmins and Seeman criteria) will be included. Clinical variables of anxiety, neuroticism, allostatic load, neurobiochemical studies, neurocognition and quality of life will be determined prior and periodically (1, 2, 4, 8, and 12 weeks) after treatment (on demand of alprazolam from 0.75 mg/day to 3.0 mg/day). A sample of n=55/182 patients will be considered enough to detect variables higher than 25% (pretreatment vs post-treatment or significant correlations) with a 1-ß power of 0–80. t Test and/or non-parametric test, and Pearson's test for correlation analysis will be determined. Ethics and dissemination This study protocol was approved by an Independent Ethics Committee of FEFyM (Foundation for Pharmacological Studies and Drugs, Buenos Aires) and by regulatory

  5. Mismatch or allostatic load? Timing of life adversity differentially shapes gray matter volume and anxious temperament.

    PubMed

    Kuhn, Manuel; Scharfenort, Robert; Schümann, Dirk; Schiele, Miriam A; Münsterkötter, Anna L; Deckert, Jürgen; Domschke, Katharina; Haaker, Jan; Kalisch, Raffael; Pauli, Paul; Reif, Andreas; Romanos, Marcel; Zwanzger, Peter; Lonsdorf, Tina B

    2016-04-01

    Traditionally, adversity was defined as the accumulation of environmental events (allostatic load). Recently however, a mismatch between the early and the later (adult) environment (mismatch) has been hypothesized to be critical for disease development, a hypothesis that has not yet been tested explicitly in humans. We explored the impact of timing of life adversity (childhood and past year) on anxiety and depression levels (N = 833) and brain morphology (N = 129). Both remote (childhood) and proximal (recent) adversities were differentially mirrored in morphometric changes in areas critically involved in emotional processing (i.e. amygdala/hippocampus, dorsal anterior cingulate cortex, respectively). The effect of adversity on affect acted in an additive way with no evidence for interactions (mismatch). Structural equation modeling demonstrated a direct effect of adversity on morphometric estimates and anxiety/depression without evidence of brain morphology functioning as a mediator. Our results highlight that adversity manifests as pronounced changes in brain morphometric and affective temperament even though these seem to represent distinct mechanistic pathways. A major goal of future studies should be to define critical time periods for the impact of adversity and strategies for intervening to prevent or reverse the effects of adverse childhood life experiences.

  6. The effects of allostatic load on neural systems subserving motivation, mood regulation, and social affiliation.

    PubMed

    Beauchaine, Theodore P; Neuhaus, Emily; Zalewski, Maureen; Crowell, Sheila E; Potapova, Natalia

    2011-11-01

    The term allostasis, which is defined as stability through change, has been invoked repeatedly by developmental psychopathologists to describe long-lasting and in some cases permanent functional alterations in limbic-hypothalamic-pituitary-adrenal axis responding following recurrent and/or prolonged exposure to stress. Increasingly, allostatic load models have also been invoked to describe psychological sequelae of abuse, neglect, and other forms of maltreatment. In contrast, neural adaptations to stress, including those incurred by monoamine systems implicated in (a) mood and emotion regulation, (b) behavioral approach, and (c) social affiliation and attachment, are usually not included in models of allostasis. Rather, structural and functional alterations in these systems, which are exquisitely sensitive to prolonged stress exposure, are usually explained as stress mediators, neural plasticity, and/or programming effects. Considering these mechanisms as distinct from allostasis is somewhat artificial given overlapping functions and intricate coregulation of monoamines and the limbic-hypothalamic-pituitary-adrenal axis. It also fractionates literatures that should be mutually informative. In this article, we describe structural and functional alterations in serotonergic, dopaminergic, and noradrenergic neural systems following both acute and prolonged exposure to stress. Through increases in behavioral impulsivity, trait anxiety, mood and emotion dysregulation, and asociality, alterations in monoamine functioning have profound effects on personality, attachment relationships, and the emergence of psychopathology. PMID:22018077

  7. Mismatch or allostatic load? Timing of life adversity differentially shapes gray matter volume and anxious temperament.

    PubMed

    Kuhn, Manuel; Scharfenort, Robert; Schümann, Dirk; Schiele, Miriam A; Münsterkötter, Anna L; Deckert, Jürgen; Domschke, Katharina; Haaker, Jan; Kalisch, Raffael; Pauli, Paul; Reif, Andreas; Romanos, Marcel; Zwanzger, Peter; Lonsdorf, Tina B

    2016-04-01

    Traditionally, adversity was defined as the accumulation of environmental events (allostatic load). Recently however, a mismatch between the early and the later (adult) environment (mismatch) has been hypothesized to be critical for disease development, a hypothesis that has not yet been tested explicitly in humans. We explored the impact of timing of life adversity (childhood and past year) on anxiety and depression levels (N = 833) and brain morphology (N = 129). Both remote (childhood) and proximal (recent) adversities were differentially mirrored in morphometric changes in areas critically involved in emotional processing (i.e. amygdala/hippocampus, dorsal anterior cingulate cortex, respectively). The effect of adversity on affect acted in an additive way with no evidence for interactions (mismatch). Structural equation modeling demonstrated a direct effect of adversity on morphometric estimates and anxiety/depression without evidence of brain morphology functioning as a mediator. Our results highlight that adversity manifests as pronounced changes in brain morphometric and affective temperament even though these seem to represent distinct mechanistic pathways. A major goal of future studies should be to define critical time periods for the impact of adversity and strategies for intervening to prevent or reverse the effects of adverse childhood life experiences. PMID:26568620

  8. Mismatch or allostatic load? Timing of life adversity differentially shapes gray matter volume and anxious temperament

    PubMed Central

    Kuhn, Manuel; Scharfenort, Robert; Schümann, Dirk; Schiele, Miriam A.; Münsterkötter, Anna L.; Deckert, Jürgen; Domschke, Katharina; Haaker, Jan; Kalisch, Raffael; Pauli, Paul; Reif, Andreas; Romanos, Marcel; Zwanzger, Peter

    2016-01-01

    Traditionally, adversity was defined as the accumulation of environmental events (allostatic load). Recently however, a mismatch between the early and the later (adult) environment (mismatch) has been hypothesized to be critical for disease development, a hypothesis that has not yet been tested explicitly in humans. We explored the impact of timing of life adversity (childhood and past year) on anxiety and depression levels (N = 833) and brain morphology (N = 129). Both remote (childhood) and proximal (recent) adversities were differentially mirrored in morphometric changes in areas critically involved in emotional processing (i.e. amygdala/hippocampus, dorsal anterior cingulate cortex, respectively). The effect of adversity on affect acted in an additive way with no evidence for interactions (mismatch). Structural equation modeling demonstrated a direct effect of adversity on morphometric estimates and anxiety/depression without evidence of brain morphology functioning as a mediator. Our results highlight that adversity manifests as pronounced changes in brain morphometric and affective temperament even though these seem to represent distinct mechanistic pathways. A major goal of future studies should be to define critical time periods for the impact of adversity and strategies for intervening to prevent or reverse the effects of adverse childhood life experiences. PMID:26568620

  9. Self Reported Childhood Difficulties, Adult Multimorbidity and Allostatic Load. A Cross-Sectional Analysis of the Norwegian HUNT Study

    PubMed Central

    Tomasdottir, Margret Olafia; Sigurdsson, Johann Agust; Petursson, Halfdan; Kirkengen, Anna Luise; Krokstad, Steinar; McEwen, Bruce; Hetlevik, Irene; Getz, Linn

    2015-01-01

    Background Multimorbidity receives increasing scientific attention. So does the detrimental health impact of adverse childhood experiences (ACE). Aetiological pathways from ACE to complex disease burdens are under investigation. In this context, the concept of allostatic overload is relevant, denoting the link between chronic detrimental stress, widespread biological perturbations and disease development. This study aimed to explore associations between self-reported childhood quality, biological perturbations and multimorbidity in adulthood. Materials and Methods We included 37 612 participants, 30–69 years, from the Nord-Trøndelag Health Study, HUNT3 (2006–8). Twenty one chronic diseases, twelve biological parameters associated with allostatic load and four behavioural factors were analysed. Participants were categorised according to the self-reported quality of their childhood, as reflected in one question, alternatives ranging from ‘very good’ to ‘very difficult’. The association between childhood quality, behavioural patterns, allostatic load and multimorbidity was compared between groups. Results Overall, 85.4% of participants reported a ‘good’ or ‘very good’ childhood; 10.6% average, 3.3% ‘difficult’ and 0.8% ‘very difficult’. Childhood difficulties were reported more often among women, smokers, individuals with sleep problems, less physical activity and lower education. In total, 44.8% of participants with a very good childhood had multimorbidity compared to 77.1% of those with a very difficult childhood (Odds ratio: 5.08; 95% CI: 3.63–7.11). Prevalences of individual diseases also differed significantly according to childhood quality; all but two (cancer and hypertension) showed a significantly higher prevalence (p<0.05) as childhood was categorised as more difficult. Eight of the 12 allostatic parameters differed significantly between childhood groups. Conclusions We found a general, graded association between self

  10. A streamlined approach for assessing the Allostatic Load Index in industrial employees.

    PubMed

    Mauss, Daniel; Jarczok, Marc N; Fischer, Joachim E

    2015-01-01

    Work stress is common and can lead to various bodily dysfunctions. The Allostatic Load Index (ALI) is a tool to measure the wear and tear of the body caused by chronic stress. This cross-sectional study aimed to explore the association of work-related stress and ALI in German industrial employees. A short form ALI should be developed for practical use of company physicians. In this exploration of an industrial cohort (n = 3797; 79.3% male), work stress was measured by the effort-reward imbalance (ERI) questionnaire in 2009-2011. ALI was calculated using 15 variables including anthropometric data, heart rate variability, as well as blood and urine samples based on predefined subclinical cut-off values. Differences in ALI related to low (≤1) and high (>1) ERI categories were tested. Logistic regression models estimated odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the association between ALI and work stress controlling for multiple confounders. Employees exposed to high work stress showed higher ALI scores (p < 0.001) compared to those with low stress levels. In multivariable models, ALI was associated with work stress (OR 1.19 [95% CI: 1.00, 1.42]; p < 0.05) following adjustment for a range of potential confounders. By reducing ALI parameters to five variables this association increased modestly and remained statistically significant (OR 1.27 [95% CI: 1.05, 1.54]; p < 0.05). The results indicate that work stress is associated with ALI in German industrial employees. A short form index seems to be a promising approach for occupational health practitioners. The results should be validated in further longitudinal explorations defining a standard set of variables including gender-related thresholds.

  11. A streamlined approach for assessing the Allostatic Load Index in industrial employees.

    PubMed

    Mauss, Daniel; Jarczok, Marc N; Fischer, Joachim E

    2015-01-01

    Work stress is common and can lead to various bodily dysfunctions. The Allostatic Load Index (ALI) is a tool to measure the wear and tear of the body caused by chronic stress. This cross-sectional study aimed to explore the association of work-related stress and ALI in German industrial employees. A short form ALI should be developed for practical use of company physicians. In this exploration of an industrial cohort (n = 3797; 79.3% male), work stress was measured by the effort-reward imbalance (ERI) questionnaire in 2009-2011. ALI was calculated using 15 variables including anthropometric data, heart rate variability, as well as blood and urine samples based on predefined subclinical cut-off values. Differences in ALI related to low (≤1) and high (>1) ERI categories were tested. Logistic regression models estimated odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the association between ALI and work stress controlling for multiple confounders. Employees exposed to high work stress showed higher ALI scores (p < 0.001) compared to those with low stress levels. In multivariable models, ALI was associated with work stress (OR 1.19 [95% CI: 1.00, 1.42]; p < 0.05) following adjustment for a range of potential confounders. By reducing ALI parameters to five variables this association increased modestly and remained statistically significant (OR 1.27 [95% CI: 1.05, 1.54]; p < 0.05). The results indicate that work stress is associated with ALI in German industrial employees. A short form index seems to be a promising approach for occupational health practitioners. The results should be validated in further longitudinal explorations defining a standard set of variables including gender-related thresholds. PMID:25976030

  12. Marital Conflict, Allostatic Load, and the Development of Children's Fluid Cognitive Performance

    ERIC Educational Resources Information Center

    Hinnant, J. Benjamin; El-Sheikh, Mona; Keiley, Margaret; Buckhalt, Joseph A.

    2013-01-01

    Relations between marital conflict, children's respiratory sinus arrhythmia (RSA), and fluid cognitive performance were examined over 3 years to assess allostatic processes. Participants were 251 children reporting on marital conflict, baseline RSA, and RSA reactivity (RSA-R) to a lab challenge were recorded, and fluid cognitive performance…

  13. Intelligence and socioeconomic position in childhood in relation to frailty and cumulative allostatic load in later life: the Lothian Birth Cohort 1936

    PubMed Central

    Gale, Catharine R; Booth, Tom; Starr, John M; Deary, Ian J

    2016-01-01

    Background Information on childhood determinants of frailty or allostatic load in later life is sparse. We investigated whether lower intelligence and greater socioeconomic disadvantage in childhood increased the risk of frailty and higher allostatic load, and explored the mediating roles of adult socioeconomic position, educational attainment and health behaviours. Methods Participants were 876 members of the Lothian Birth Cohort 1936 whose intelligence was assessed at age 11. At age 70, frailty was assessed using the Fried criteria. Measurements were made of fibrinogen, triglyceride, total and high-density lipoprotein cholesterol, albumin, glycated haemoglobin, C reactive protein, body mass index and blood pressure, from which an allostatic load score was calculated. Results In sex-adjusted analyses, lower intelligence and lower social class in childhood were associated with an increased risk of frailty: relative risks (95% CIs) were 1.57 (1.21 to 2.03) for a SD decrease in intelligence and 1.48 (1.12 to 1.96) for a category decrease in social class. In the fully adjusted model, both associations ceased to be significant: relative risks were 1.13 (0.83 to 1.54) and 1.19 (0.86 to 1.61), respectively. Educational attainment had a significant mediating effect. Lower childhood intelligence in childhood, but not social class, was associated with higher allostatic load. The sex-adjusted coefficient for allostatic load for a SD decrease in intelligence was 0.10 (0.07 to 0.14). In the fully adjusted model, this association was attenuated but remained significant (0.05 (0.01 to 0.09)). Conclusions Further research will need to investigate the mechanisms whereby lower childhood intelligence is linked to higher allostatic load in later life. PMID:26700299

  14. A Longitudinal Investigation of Race, Socioeconomic Status, and Psychosocial Mediators of Allostatic Load in Midlife Women: Findings from the Study of Women’s Health Across the Nation

    PubMed Central

    Upchurch, Dawn M.; Stein, Judith; Greendale, Gail A.; Chyu, Laura; Tseng, Chi-Hong; Huang, Mei-Hua; Lewis, Tené T.; Kravitz, Howard M.; Seeman, Teresa

    2015-01-01

    Objectives This research sought to assess racial and SES differences in level and change in allostatic load (AL) over time in midlife women and to test whether psychosocial factors mediate these relationships. These factors were: discrimination, perceived stress, and hostility. Methods Longitudinal data obtained from the Study of Women’s Health Across the Nation SWAN were used (n = 2063; mean age at baseline = 46.0). Latent growth curve (LGC) models evaluated the impact of demographic, menopausal, and psychosocial variables on level and change in AL over 8 years. Results Direct effects: High levels of discrimination and hostility significantly predicted higher AL (path coefficients 0.05, 0.05 respectively). High perceived stress significantly predicted a faster rate of increase of AL (path coefficient 0.06). Racial and socioeconomic status (SES) differentials were present, with African American race (path coefficient 0.23), low income (path coefficient −0.15), and low education (path coefficient −0.08) significantly predicted high AL level. Indirect effects: Significant indirect effects were found for African American race, less income, and lower education through higher discrimination, perceived stress, and hostility on level and rate of AL. Conclusion This was one of the first studies that investigated AL over multiple time periods and results supported AL as a cumulative phenomenon, affected by multiple psychosocial and demographic factors. The results suggest the complex ways in which race, SES, and psychosocial factors operate to influence AL. PMID:25886828

  15. The APOA1/C3/A4/A5 cluster and markers of allostatic load in the Boston Puerto Rican Health Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The APOA1/C3/A4/A5 cluster encodes key regulators of plasma lipids. Interactions between dietary factors and single nucleotide polymorphisms (SNPs) in the cluster have been reported. Allostatic load, or physiological dysregulation in response to stress, has been implicated in shaping health disparit...

  16. Reaction Time in Adolescence, Cumulative Allostatic Load, and Symptoms of Anxiety and Depression in Adulthood: The West of Scotland Twenty-07 Study

    PubMed Central

    Gale, Catharine R.; Batty, G. David; Cooper, Sally-Ann; Deary, Ian J.; Der, Geoff; McEwen, Bruce S.; Cavanagh, Jonathan

    2015-01-01

    ABSTRACT Objective To examine the relation between reaction time in adolescence and subsequent symptoms of anxiety and depression and investigate the mediating role of sociodemographic measures, health behaviors, and allostatic load. Methods Participants were 705 members of the West of Scotland Twenty-07 Study. Choice reaction time was measured at age 16. At age 36 years, anxiety and depression were assessed with the 12-item General Health Questionnaire (GHQ) and the Hospital Anxiety and Depression Scale (HADS), and measurements were made of blood pressure, pulse rate, waist-to-hip ratio, and total and high-density lipoprotein cholesterol, C-reactive protein, albumin, and glycosolated hemoglobin from which allostatic load was calculated. Results In unadjusted models, longer choice reaction time at age 16 years was positively associated with symptoms of anxiety and depression at age 36 years: for a standard deviation increment in choice reaction time, regression coefficients (95% confidence intervals) for logged GHQ score, and square-root–transformed HADS anxiety and depression scores were 0.048 (0.016–0.080), 0.064 (0.009–0.118), and 0.097 (0.032–0.163) respectively. Adjustment for sex, parental social class, GHQ score at age 16 years, health behaviors at age 36 years and allostatic load had little attenuating effect on the association between reaction time and GHQ score, but weakened those between reaction time and the HADS subscales. Part of the effect of reaction time on depression was mediated through allostatic load; this mediating role was of borderline significance after adjustment. Conclusions Adolescents with slower processing speed may be at increased risk for anxiety and depression. Cumulative allostatic load may partially mediate the relation between processing speed and depression. PMID:25984823

  17. Mediating pathways between parental socio-economic position and allostatic load in mid-life: Findings from the 1958 British birth cohort.

    PubMed

    Barboza Solís, Cristina; Fantin, Romain; Castagné, Raphaële; Lang, Thierry; Delpierre, Cyrille; Kelly-Irving, Michelle

    2016-09-01

    Understanding how human environments affect our health by "getting under the skin" and penetrating the cells, organs and physiological systems of our bodies is a key tenet in public health research. Here, we examine the idea that early life socioeconomic position (SEP) can be biologically embodied, potentially leading to the production of health inequalities across population groups. Allostatic load (AL), a composite measure of overall physiological wear-and-tear, could allow for a better understanding of the potential biological pathways playing a role in the construction of the social gradient in adult health. We investigate the factors mediating the link between two components of parental SEP, maternal education (ME) and parental occupation (PO), and AL at 44 years. Data was used from 7573 members of the 1958 British birth cohort follow-up to age 44. AL was constructed using 14 biomarkers representing four physiological systems. We assessed the contribution of financial/materialist, psychological/psychosocial, educational, and health behaviors/BMI pathways over the life course, in mediating the associations between ME, PO and AL. ME and PO were mediated by three pathways: educational, material/financial, and health behaviors, for both men and women. A better understanding of embodiment processes leading to disease development may contribute to developing adapted public policies aiming to reduce health inequalities. PMID:27485729

  18. Higher adherence to a diet score based on American Heart Association recommendations is associated with lower odds of allostatic load and metabolic syndrome in Puerto Rican adults.

    PubMed

    Mattei, Josiemer; Bhupathiraju, Shilpa; Tucker, Katherine L

    2013-11-01

    A score based on diet and lifestyle recommendations from the AHA has been associated with cardiovascular risk factors. We aimed to assess whether the diet components alone were associated with metabolic syndrome (MetS) and allostatic load (AL; a composite measure of 10 physiologically dysregulated variables). The diet score ranged from 0 to 90 and included intake components for dietary fats, fruits and vegetables, whole grains, salt, added sugars, and alcohol and was tested in a cross-sectional analysis of 1318 Puerto Rican adults (aged 45-75 y; 72% women) living in Boston, MA. The mean ± SD diet score was 28.0 ± 9.9 for men and 30.0 ± 10.1 for women. Replicating findings from a previous study in this cohort that used both the diet and lifestyle components, we observed associations between the diet-only score and insulin, waist circumference, and HDL cholesterol. We found novel significant associations between the continuous diet score and AL components, namely an inverse association with urinary cortisol and a positive association with serum dehydroepiandrosterone sulfate in women as well as an inverse association with urinary norepinephrine in men (all P < 0.05). In multinomial logistic regression, every 10 AHA diet score units were associated with 22% (95% CI: 1, 38; P = 0.043) lower odds of having ≥6 (vs. ≤2) dysregulated AL components in women. In men, every 10 diet score units were associated with lower odds of MetS (OR: 0.69; 95% CI: 0.52, 0.93; P = 0.016). Following AHA recommendations for a healthy diet may protect against the development of components of MetS and AL in Puerto Rican adults.

  19. Relationship of Serum Vitamin D Concentrations and Allostatic Load as a Measure of Cumulative Biological Risk among the US Population: A Cross-Sectional Study

    PubMed Central

    Frei, Regina; Haile, Sarah R.; Mutsch, Margot; Rohrmann, Sabine

    2015-01-01

    Introduction The allostatic load (AL) index is a multi-systemic measure of physiologic dysregulation known to be associated with chronic exposure to stress and adverse health outcomes. We examined the relationship between AL and serum 25-hydroxyvitamin D (25(OH)D) concentration in non-institutionalized US adults. Methods Data from the Third National Health and Nutrition Examination Survey (NHANES III, 1988–94) were used to calculate two versions of AL including 9 biomarkers and another two with 14 biomarkers (systolic and diastolic blood pressure, pulse rate, serum cholesterol, serum HDL-cholesterol, glycated hemoglobin, sex-specific waist-to-hip ratio, serum albumin, and serum C-reactive protein for AL1, and, additionally body mass index, serum triglyceride, serum creatinine, and serum herpes I & II antibodies for AL2), each set defined by predefined cut-offs or by quartiles. Serum vitamin D concentration was ranked into quartiles. Logistic regression, Poisson regression and linear regression were used to examine the association of serum 25(OH)D concentrations on AL, after adjusting for biological, physiological, socioeconomic, lifestyle, and health variables. Results Odds Ratios (OR) for high AL of the lowest 25(OH)D serum quartile were between 1.45 (95% CI: 1.28, 1.67) and 1.79 (95% CI: 1.39, 2.32) for the fully adjusted model, depending on AL version. Inverse relationships between vitamin D serum concentrations were observed for all AL versions and every adjustment. This relationship was consistent after stratification by sex, age or ethnic background. Sensitivity to low 25(OH)D concentrations was highest among the youngest group (20–39 years) with an OR of 2.11 (95% CI: 1.63, 2.73) for the lowest vitamin D quartile Q1. Conclusions Vitamin D had a consistent and statistically significant inverse association with all tested models of high AL, which remained consistent after adjusting for biological, socioeconomic, lifestyle and health variables. Our study

  20. Hormesis, allostatic buffering capacity and physiological mechanism of physical activity: a new theoretic framework.

    PubMed

    Li, Guolin; He, Hong

    2009-05-01

    Despite great progress made in sports medicine, the physiological mechanism of moderate physical activity-induced physical fitness remains only partly understood. Combined with the hormetic characteristic of physical activity and property of allostasis, we first propose the hormesis induced allostatic buffering capacity enhancement as a physiological mechanism to explain the moderate physical activity-induced physical fitness. As stressful stimulus, physical activity can induce several stresses in the host, including eustress ('good stress') and distress ('bad stress'), which may have both positive and negative effects. Too little or too much physical activities will introduce too weak eustress or too strong distress and result in allostasis load through weakening allostatic buffering capacity or damaging allostatic buffering capacity respectively. However, moderate physical activities will introduce eustress and contribute to the hormesis induced allostatic buffering capacity enhancement, which benefits organism.

  1. A groundwork for allostatic neuro-education

    PubMed Central

    Gerdes, Lee; Tegeler, Charles H.; Lee, Sung W.

    2015-01-01

    We propose to enliven educational practice by marrying a conception of education as guided human development, to an advanced scientific understanding of the brain known as allostasis (stability through change). The result is a groundwork for allostatic neuro-education (GANE). Education as development encompasses practices including the organic (homeschooling and related traditions), cognitive acquisition (emphasis on standards and testing), and the constructivist (aimed to support adaptive creativity for both learner and society). Allostasis views change to be the norm in biology, defines success in contexts of complex natural environments rather than controlled settings, and identifies the brain as the organ of central command. Allostatic neuro-education contrasts with education focused dominantly on testing, or neuroscience based on homeostasis (stability through constancy). The GANE perspective is to view learners in terms of their neurodevelopmental trajectories; its objective is to support authentic freedom, mediated by competent, integrated, and expansive executive functionality (concordant with the philosophy of freedom of Rudolf Steiner); and its strategy is to be attuned to rhythms in various forms (including those of autonomic arousal described in polyvagal theory) so as to enable experiential excitement for learning. The GANE presents a variety of testable hypotheses, and studies that explore prevention or mitigation of the effects of early life adversity or toxic stress on learning and development may be of particular importance. Case studies are presented illustrating use of allostatic neurotechnology by an adolescent male carrying diagnoses of Asperger’s syndrome and attention-deficit hyperactivity disorder, and a grade school girl with reading difficulties. The GANE is intended as a re-visioning of education that may serve both learners and society to be better prepared for the accelerating changes of the 21st century. PMID:26347688

  2. A groundwork for allostatic neuro-education.

    PubMed

    Gerdes, Lee; Tegeler, Charles H; Lee, Sung W

    2015-01-01

    We propose to enliven educational practice by marrying a conception of education as guided human development, to an advanced scientific understanding of the brain known as allostasis (stability through change). The result is a groundwork for allostatic neuro-education (GANE). Education as development encompasses practices including the organic (homeschooling and related traditions), cognitive acquisition (emphasis on standards and testing), and the constructivist (aimed to support adaptive creativity for both learner and society). Allostasis views change to be the norm in biology, defines success in contexts of complex natural environments rather than controlled settings, and identifies the brain as the organ of central command. Allostatic neuro-education contrasts with education focused dominantly on testing, or neuroscience based on homeostasis (stability through constancy). The GANE perspective is to view learners in terms of their neurodevelopmental trajectories; its objective is to support authentic freedom, mediated by competent, integrated, and expansive executive functionality (concordant with the philosophy of freedom of Rudolf Steiner); and its strategy is to be attuned to rhythms in various forms (including those of autonomic arousal described in polyvagal theory) so as to enable experiential excitement for learning. The GANE presents a variety of testable hypotheses, and studies that explore prevention or mitigation of the effects of early life adversity or toxic stress on learning and development may be of particular importance. Case studies are presented illustrating use of allostatic neurotechnology by an adolescent male carrying diagnoses of Asperger's syndrome and attention-deficit hyperactivity disorder, and a grade school girl with reading difficulties. The GANE is intended as a re-visioning of education that may serve both learners and society to be better prepared for the accelerating changes of the 21st century. PMID:26347688

  3. Cumulative Risk, Maternal Responsiveness, and Allostatic Load among Young Adolescents

    ERIC Educational Resources Information Center

    Evans, Gary W.; Kim, Pilyoung; Ting, Albert H.; Tesher, Harris B.; Shannis, Dana

    2007-01-01

    The purpose of this study was to examine the impact of cumulative risk exposure in concert with maternal responsiveness on physiological indicators of chronic stress in children and youth. Middle-school children exposed to greater accumulated psychosocial (e.g., family turmoil, poverty) and physical (e.g., crowding, substandard housing) risk…

  4. Shock Loading of Granular Ni/Al Composites. Part 1. Mechanics of Loading

    DOE PAGES

    Cherukara, Mathew J.; Germann, Timothy C.; Kober, Edward M.; Strachan, Alejandro

    2014-10-16

    We present molecular dynamics simulations of the thermomechanical response under shock loading of a granular material consisting of laminated Ni/Al grains. We observe two regimes: At low piston velocities (up ≲ 1km/s), the shock wave is diffuse, and the width of the shock front decreases with increasing piston velocity. Beyond a critical shock strength, however, the width remains relatively constant at approximately the mean grain radius. This change in behavior follows from an evolution of the mechanism of compaction with increasing insult strength. Furthermore, the mechanism evolves from plastic deformation-mediated pore collapse for relatively weak shocks, to solid extrusion andmore » fluid ejecta filling pores ahead of the shock front at intermediate strengths, and finally to atomic jetting into the pore for very strong shocks (up ≳ 2 km/s). High-energy fluid ejecta into pores leads to the formation of flow vorticity and can result in a large fraction of the input energy localizing into translational kinetic energy components including the formation of hot spots. This has implications for the mechanical mixing of Ni and Al in these reactive composites.« less

  5. Shock Loading of Granular Ni/Al Composites. Part 1. Mechanics of Loading

    SciTech Connect

    Cherukara, Mathew J.; Germann, Timothy C.; Kober, Edward M.; Strachan, Alejandro

    2014-10-16

    We present molecular dynamics simulations of the thermomechanical response under shock loading of a granular material consisting of laminated Ni/Al grains. We observe two regimes: At low piston velocities (up ≲ 1km/s), the shock wave is diffuse, and the width of the shock front decreases with increasing piston velocity. Beyond a critical shock strength, however, the width remains relatively constant at approximately the mean grain radius. This change in behavior follows from an evolution of the mechanism of compaction with increasing insult strength. Furthermore, the mechanism evolves from plastic deformation-mediated pore collapse for relatively weak shocks, to solid extrusion and fluid ejecta filling pores ahead of the shock front at intermediate strengths, and finally to atomic jetting into the pore for very strong shocks (up ≳ 2 km/s). High-energy fluid ejecta into pores leads to the formation of flow vorticity and can result in a large fraction of the input energy localizing into translational kinetic energy components including the formation of hot spots. This has implications for the mechanical mixing of Ni and Al in these reactive composites.

  6. On the application of load relaxation in characterizing superplastic Al-Li 8090

    SciTech Connect

    Booeshaghi, F.; Garmestani, H.

    1999-01-22

    High strain rate sensitivity is one of the main features of superplastic deformation which accounts for elongation to large strains ({var_epsilon} {ge} 1.5). Strain-rate sensitivity is typically calculated as the slope of the log {sigma} versus log {dot {var_epsilon}} curve where {sigma} is the steady state flow stress and {dot {epsilon}} is the inelastic strain-rate. A variety of mechanical testing methods are used to evaluate strain-rate change test, and load relaxation tests. In this paper, the use of the load relaxation experiment to obtain the stress/strain rate behavior of an Al-Li 8090 superplastic material is investigated and compared to the strain-rate change tests. The strain rate change tests are found to be highly influenced by prior loading conditions and only valid for incrementally increasing tensile loads. Relaxation tests are found to be very effective for all ranges of strain rates. These tests can also be influenced by transient effects which are primarily due to anelasticity. Such transients can be avoided if the specimen is loaded to fully loaded (steady state) region prior to relaxation.

  7. Effect of Texture on Fatigue Properties of Age-Hardened Al Alloys Under Ultrasonic Loading

    NASA Astrophysics Data System (ADS)

    Matsusako, Hironori; Kariya, Kohji; Kawagoishi, Norio; Wang, Qingyuan; Goto, Masahiro

    Effects of texture and loading frequency on the fatigue crack growth behavior of an extruded and a drawn Al alloys of 2017-T4 were investigated under ultrasonic loading frequency (20kHz) in the relative humidity of 25% and 85%, respectively. The extruded alloy has a marked texture of (111) orientation, but this specified orientation is not observed in the drawn alloy. Most of fatigue life was occupied by the growth life of small cracks in the both alloys regardless of humidity. In the low humidity, crack growth was retarded at about 0.3 mm in length in the both alloys. Although crack growth was accelerated by high humidity in the early growth process, there was no or little influence of humidity on the growth rate of cracks over about 0.3 mm in the both alloys. After the retardation of crack growth, fracture surfaces featured with many slip planes in the extruded alloy and many facets in the drawn one, respectively. The difference in growth mechanism between short cracks (<0.3 mm) and longer ones (>0.3 mm) was caused by the environment at crack tips due to high crack growth rate under ultrasonic loading, and that between the both alloys was related to the degree of texture.

  8. Tribological Performance of NiAl Self-lubricating Matrix Composite with Addition of Graphene at Different Loads

    NASA Astrophysics Data System (ADS)

    Xiao, Yecheng; Shi, Xiaoliang; Zhai, Wenzheng; Yao, Jie; Xu, Zengshi; Chen, Long; Zhu, Qingshuai

    2015-08-01

    This research was carried out on the beneficial effect of graphene additive in self-lubricating composites for use at different loads of tribological application. The dry friction and wear behaviors of NiAl self-lubricating matrix composite with graphene (NSMG) were investigated at different loads at room temperature. Finite element method served as aided method to analyze the stress condition of contact pair, which would provide another perspective to comprehend the relationship between tribological behaviors and different degrees of load-induced deformation. In the load range of 2-16 N, the results indicated that NSMG showed excellent tribological performance at load of 16 N due to the formation of anti-friction tribo-film on the worn surface. Moreover, suitable load would lead to the contact situation transfer from multi-point contact to area contact, which could contribute to the beneficial effect on friction behavior of NSMG.

  9. Influence of shock loading on the structure/property response of Ti-48Al-2Cr-2Nb and Ti-24Al-11Nb

    SciTech Connect

    Gray, R.T. III

    1994-02-01

    Intermetallics are receiving increasing attention for applications requiring high-leverage materials possessing potentially high pay-offs such as in gas-turbine engines. While the quasi-static deformation response of a broad range of intermetallics is receiving intense scientific and engineering study, increased utilization of intermetallics under dynamic loading requires an understanding of their high-rate/shock-wave behavior. In this paper the influence of shock loading on structure/property behavior of Ti-48Al-2Cr-2Nb and Ti-24Al-11Nb is presented. The reload constitutive response of both shock-loaded intermetallics supports the dynamic deformation of both intermetallics being controlled by a Peierls mechanism. Defect generation and storage in intermetallics is compared and contrasted to that typical to conventional disordered metals and alloys.

  10. Fatigue crack growth behavior of an 8090 Al-Li alloy under mixed mode 1--mode 3 loading conditions

    SciTech Connect

    Kamat, S.V.; Prasad, N.E.

    1993-11-15

    Aluminum-lithium alloys have evoked considerable interest in recent years because of their high specific strengths and stiffness. An additional advantage of these alloys is their superior fatigue crack growth resistance as compared to the conventional aluminium alloys. However, most of the fatigue crack growth investigations have dealt with crack propagation behavior under mode 1 and loading. A recent study on monotonic fracture behavior of 8090 Al-Li alloys has shown that these alloys possess lower fracture toughness under mode 3 loading as compared to mode 1 loading. The fracture resistance under mixed mode 1 - mode 3 loading was also found to be lower than that under pure mode 1 loading. However, no experimental data is available on the mixed mode 1--mode 3 fatigue crack growth behavior in Al-Li alloys. The objective of the present paper is to study the effect of combined mode 1--mode 3 loading on the fatigue crack growth behavior of an 8090 Al-Li alloy.

  11. Disturbance of wildlife by outdoor winter recreation: allostatic stress response and altered activity-energy budgets.

    PubMed

    Arlettaz, Raphaël; Nusslé, Sébastien; Baltic, Marjana; Vogel, Peter; Palme, Rupert; Jenni-Eiermann, Susanne; Patthey, Patrick; Genoud, Michel

    2015-07-01

    Anthropogenic disturbance of wildlife is of growing conservation concern, but we lack comprehensive approaches of its multiple negative effects. We investigated several effects of disturbance by winter outdoor sports on free-ranging alpine Black Grouse by simultaneously measuring their physiological and behavioral responses. We experimentally flushed radio-tagged Black Grouse from their snow burrows, once a day, during several successive days, and quantified their stress hormone levels (corticosterone metabolites in feces [FCM] collected. from individual snow burrows). We also measured feeding time allocation (activity budgets reconstructed from radio-emitted signals) in response to anthropogenic disturbance. Finally, we estimated the related extra energy expenditure that may be incurred: based on activity budgets, energy expenditure was modeled from measures of metabolism obtained from captive birds subjected to different ambient temperatures. The pattern of FCM excretion indicated the existence of a funneling effect as predicted by the allostatic theory of stress: initial stress hormone concentrations showed a wide inter-individual variation, which decreased during experimental flushing. Individuals with low initial pre-flushing FCM values augmented their concentration, while individuals with high initial FCM values lowered it. Experimental disturbance resulted in an extension of feeding duration during the following evening foraging bout, confirming the prediction that Black Grouse must compensate for the extra energy expenditure elicited by human disturbance. Birds with low initial baseline FCM concentrations were those that spent more time foraging. These FCM excretion and foraging patterns suggest that birds with high initial FCM concentrations might have been experiencing a situation of allostatic overload. The energetic model provides quantitative estimates of extra energy expenditure. A longer exposure to ambient temperatures outside the shelter of snow

  12. Fracture toughness of quaternary Al-Li-Cu-Mg alloy under mode I, mode II, and mode III loading conditions

    SciTech Connect

    Prasad, N.E.; Kamat, S.V.; Malakondaiah, G. ); Kutumbarao, V.V. . Dept. of Metallurgical Engineering)

    1994-11-01

    The fracture toughness under mode I, mode II, and mode III loading conditions was evaluated for a quaternary 8090 Al-Li-Cu-Mg alloy in underaged and peak-aged conditions. The effect of aging was found to be significantly different for different loading conditions. The alloy in the underaged (T3) condition exhibited minimum fracture toughness under mode II loading, whereas mode I fracture toughness was the lowest in the case of the peak-aged (T8E51) condition. Significant anisotropy in the fracture resistance is observed only in case of the peak-aged alloy under mode I loading, whereas in all other cases, the fracture resistance is found to be isotropic. The fracture mode was transgranular shear in all three modes of loading in the underaged condition as well as under mode II and mode III loading in the peak-aged condition. The alloy exhibited ductile intergranular fracture under mode I loading in the peak-aged condition. The results obtained are explained on the basis of these dominant fracture mechanisms prevalent under different loading conditions.

  13. Study on load relaxation based on hot bending and sizing of Ti6Al4V alloy sheet

    NASA Astrophysics Data System (ADS)

    Po, Liu; Yingying, Zong; Debin, Shan; Bin, Guo

    2013-05-01

    The mechanism of hot sizing following sheet thermal forming of titanium alloy is considered as stress relaxation based on creep flow. A certain amount of internal stress in sheet metal parts can be relaxed during hot-sizing stage and hence the springback can be markedly reduced. Hot v-bending of Ti6Al4V sheet were carried out to study the behavior of load relaxation and springback in specimens after hot sizing, also known as shape retention. Experimental results reveal that load relaxation occurs during hot sizing following sheet v-bending. Reduction of springback angle obtained using hot sizing is obviously larger than that obtained without hot sizing under the same thermal environment. During hot sizing, springback angle decreases with increase in temperature and time, respectively. Load relaxation behavior is affected by loading method, namely constant velocity and two step loading. The linear relation between creep rate and load relaxation rate was deduced in hot-sizing stage. The calculated ratio shows good agreement with experimental data obtained by two-step loading. V-bending and sizing together with appropriate loading method are demonstrated as a good approach for stress relaxation analysis.

  14. Childhood Psychosocial Stressors and Adult Onset Arthritis: Broad Spectrum Risk Factors and Allostatic Load

    PubMed Central

    Von Korff, Michael; Alonso, Jordi; Ormel, Johan; Angermeyer, Matthais; Bruffaerts, Ronny; Fleiz, Clara; de Girolamo, Giovanni; Kessler, Ronald C.; Kovess-Masfety, Viviane; Posada-Villa, José; Scott, Kate M.; Uda, Hidenori

    2009-01-01

    Neural, endocrine and immune stress mediators are hypothesized to increase risks of diverse chronic diseases, including arthritis. Retrospective data from the World Mental Health Surveys (N=18,309) were employed to assess whether adult onset of arthritis was associated with childhood adversities and early onset psychological disorder. Cox proportional hazard models assessed the association of number of childhood adversities and the presence of early onset psychological disorder with arthritis age of onset. Controlling for age, sex and early onset mental disorder, relative to persons with no childhood adversities, persons with two adversities had increased risk of adult onset arthritis (Hazard ratio=1.27, 95% CI= 1.08, 1.50), while persons with three or more adversities had higher risk (HR=1.44, CI=1.24,1.67). Early onset depressive and/or anxiety disorder was associated with increased risk of adult-onset arthritis after controlling for childhood adversities (HR=1.43, CI=1.28, 1.61). Since psychosocial stressors may be broad spectrum risk factors that increase risks of diverse chronic conditions in later life (e.g., arthritis, heart disease, diabetes, asthma, chronic pain), prospective studies of childhood psychosocial stressors may be most productive if multiple disease outcomes are assessed in the same study. Results from this study provide methodological guidance for future prospective studies of the relationship between childhood psychosocial stressors and subsequent risk of adult onset arthritis. PERSPECTIVE Retrospective reports of early onset mood-anxiety disorder and multiple childhood adversities were independently associated with increased risk of adult onset arthritis. Carrying out prospective studies of these relationships entails significant challenges. Since childhood psychosocial stressors may be broad spectrum risk factors for diverse chronic conditions, multiple disease outcomes should be assessed in prospective studies assessing health consequences of childhood adversities. PMID:19251363

  15. Fat or lean: adjustment of endogenous energy stores to predictable and unpredictable changes in allostatic load

    USGS Publications Warehouse

    Schultner, Jannik; Kitaysky, Alexander S.; Welcker, Jorg; Hatch, Scott

    2013-01-01

    6. Overall, results of this study support the ‘lean and fit’ hypothesis. We conclude that increased energy stores may not necessarily reflect better environmental conditions experienced by individuals or predict their higher fitness. A major advantage of adopting a lean physique when environmental conditions allow may be the avoidance of additional energetic costs for moving a heavy body. In breeding seabirds, this advantage may be more important during chick-rearing. In the focal species, the secretion of glucocorticoids might be involved in regulation of energy stores within a life history stage but does not appear to mediate an adaptive shift in energy stores between the incubating and chick-rearing stages of reproduction.

  16. Superior Mechanical Properties of AlCoCrFeNiTi x High-Entropy Alloys upon Dynamic Loading

    NASA Astrophysics Data System (ADS)

    Jiao, Z. M.; Ma, S. G.; Chu, M. Y.; Yang, H. J.; Wang, Z. H.; Zhang, Y.; Qiao, J. W.

    2016-02-01

    High-entropy alloys with composition of AlCoCrFeNiTi x ( x: molar ratio; x = 0, 0.2, 0.4) under quasi-static and dynamic compression exhibit excellent mechanical properties. A positive strain-rate sensitivity of yield strength and the strong work-hardening behavior during plastic flows dominate upon dynamic loading in the present alloy system. The constitutive relationships are extracted to model flow behaviors by employing the Johnson-Cook constitutive model. Upon dynamic loading, the ultimate strength and fracture strain of AlCoCrFeNiTi x alloys are superior to most of bulk metallic glasses and in situ metallic glass matrix composites.

  17. Sustained load crack growth design data for Ti-6Al-4V titanium alloy tanks containing hydrazine

    NASA Technical Reports Server (NTRS)

    Lewis, J. C.; Kenny, J. T.

    1976-01-01

    Sustained load crack growth data for Ti-6Al-4V titanium alloy in hydrazine per MIL-P-26536 and refined hydrazine are presented. Fracture mechanics data on crack growth thresholds for heat-treated forgings, aged and unaged welds, and aged and unaged heat-affected zones are reported. Fracture mechanics design curves of crack growth threshold stress intensity versus temperature are generated from 40 to 71 C.

  18. Load-pull measurement analysis of AlGaN/GaN HEMT taking into account number of gate fingers

    NASA Astrophysics Data System (ADS)

    Tiwat, Pongthavornkamol; Guoguo, Liu; Tingting, Yuan; Yingkui, Zheng; Xinyu, Liu

    2016-06-01

    This paper investigates load-pull measurement of AlGaN/GaN high electron mobility transistors (HEMTs) at different numbers of gate fingers. Scalable small-signal models are extracted to analyze the relationship between each model's parameters and the number of device's gate fingers. The simulated S-parameters from the small-signal models are compared with the reflection coefficients measured from the load-pull measurement system at X-band frequencies of 8.8 and 10.4 GHz. The dependency between the number of device's gate fingers and load-pull characterization is presented. Project supported by the National Natural Science Foundation of China (No. 61204086).

  19. Deformation Behavior Immediately After Indentation Load Change in Ultrafine-Grained Al-Mg Solid Solution Alloys

    NASA Astrophysics Data System (ADS)

    Takagi, Hidenari; Fujiwara, Masami

    2016-06-01

    Instrumented indentation tests were performed to study how grain boundaries and solute atoms affect creep and instantaneous plastic deformation in ultrafine-grained (UFG) Al-Mg solid solution alloys with average grain size d = 0.3 - 1.0 μm at T = 373 K. In the results for Al-1.0 mol% Mg, the degree of instantaneous plastic displacement generated with a rapid increase in the load was smaller when the grain diameter was smaller. On the other hand, creep occurs more readily in materials with a smaller grain diameter. When the load was rapidly decreased during creep, the indenter displacement gradually decreased over time. The degree of reverse creep that occurs is greater when the grain diameter is smaller. In light of these test results and reports in the related literature, reverse creep is thought to occur because of inverted movement of piled-up dislocations near the grain boundaries. For the case of Al- xMg ( x = 0.5, 1.0, 2.0 mol%), the results show that as the solute concentration increases, the occurrence of instantaneous plastic deformation, creep, and reverse creep becomes less likely. Overall, the results indicate that the plastic deformation behavior obtained by the testing conditions of present study for UFG Al-Mg alloys could be explained based on understanding of the behavior of course-grained materials.

  20. Subcritical crack growth of Ti-6Al-4V at room temperature under high stress-ratio loading

    SciTech Connect

    Thomas, J.P.

    1998-11-13

    Ti-6Al-4V is a two phase {alpha}-{beta} titanium alloy commonly used for turbine fan and compressor components. The crack growth behavior of Ti-6Al-4V and the role played by various material, mechanical, and environmental factors has been thoroughly investigated. This alloy is also susceptible to crack growth under sustained loading in air (SLC), and both hydrogen assisted cracking and low temperature creep mechanisms have been used to explain this susceptibility. Very little information is available on high R-ratio fatigue crack growth of Ti-6Al-4V and the role played by SLC on the fatigue process. In order to gain better understanding of the cracking behavior of this alloy under ripple loading conditions, room temperature, high stress-ratio (R {ge} 0.9) fatigue and SLC experiments have been conducted on a Ti-6Al-4V plate forging material in the duplex-annealed (DA) condition. The results of this investigation,namely, fatigue crack growth rates (CGR) as a function of stress intensity; SLC data; and scanning electron microscopy of the fatigue and SLC fracture surfaces are reported below.

  1. Testing the Nanoparticle-Allostatic Cross Adaptation-Sensitization Model for Homeopathic Remedy Effects

    PubMed Central

    Bell, Iris R.; Koithan, Mary; Brooks, Audrey J.

    2012-01-01

    Key concepts of the Nanoparticle-Allostatic Cross-Adaptation-Sensitization (NPCAS) Model for the action of homeopathic remedies in living systems include source nanoparticles as low level environmental stressors, heterotypic hormesis, cross-adaptation, allostasis (stress response network), time-dependent sensitization with endogenous amplification and bidirectional change, and self-organizing complex adaptive systems. The model accommodates the requirement for measurable physical agents in the remedy (source nanoparticles and/or source adsorbed to silica nanoparticles). Hormetic adaptive responses in the organism, triggered by nanoparticles; bipolar, metaplastic change, dependent on the history of the organism. Clinical matching of the patient’s symptom picture, including modalities, to the symptom pattern that the source material can cause (cross-adaptation and cross-sensitization). Evidence for nanoparticle-related quantum macro-entanglement in homeopathic pathogenetic trials. This paper examines research implications of the model, discussing the following hypotheses: Variability in nanoparticle size, morphology, and aggregation affects remedy properties and reproducibility of findings. Homeopathic remedies modulate adaptive allostatic responses, with multiple dynamic short- and long-term effects. Simillimum remedy nanoparticles, as novel mild stressors corresponding to the organism’s dysfunction initiate time-dependent cross-sensitization, reversing the direction of dysfunctional reactivity to environmental stressors. The NPCAS model suggests a way forward for systematic research on homeopathy. The central proposition is that homeopathic treatment is a form of nanomedicine acting by modulation of endogenous adaptation and metaplastic amplification processes in the organism to enhance long-term systemic resilience and health. PMID:23290882

  2. Improved wear resistance of functional diamond like carbon coated Ti-6Al-4V alloys in an edge loading conditions.

    PubMed

    Choudhury, Dipankar; Lackner, Jürgen M; Major, Lukasz; Morita, Takehiro; Sawae, Yoshinori; Bin Mamat, Azuddin; Stavness, Ian; Roy, Chanchal K; Krupka, Ivan

    2016-06-01

    This study investigates the durability of functional diamond-like carbon (DLC) coated titanium alloy (Ti-6Al-4V) under edge loading conditions for application in artificial hip joints. The multilayered (ML) functional DLC coatings consist of three key layers, each of these layers were designed for specific functions such as increasing fracture strength, adapting stress generation and enhancing wear resistance. A 'ball-on-disk' multi-directional wear tester was used in the durability test. Prior to the wear testing, surface hardness, modulus elasticity and Raman intensity were measured. The results revealed a significant wear reduction to the DLC coated Ti-6Al-4V disks compared to that of non-coated Ti-6Al-4V disks. Remarkably, the counterpart Silicon Nitride (Si3N4) balls also yielded lowered specific wear rate while rubbed against the coated disks. Hence, the pairing of a functional multilayered DLC and Si3N4 could be a potential candidate to orthopedics implants, which would perform a longer life-cycle against wear caused by edge loading. PMID:27085502

  3. Kinetics and fracture behavior under cycle loading of an Al-Cu-Mg-Ag alloy

    NASA Astrophysics Data System (ADS)

    Gazizov, M. R.; Kaibyshev, R. O.

    2016-07-01

    The behavior of aluminum alloy AA2139 subjected to T6 treatment, including solution treatment and artificial aging, has been studied using cyclic loading with a constant total strain amplitude. Upon low-cyclic fatigue in the range of total strain amplitudes ɛac of 0.4-1.0%, the cyclic behavior of the AA2139-T6 alloy is determined by the processes that occur under the conditions of predominance of the elastic deformation over plastic deformation. The AA2139 alloy exhibits stability to cyclic loading without significant softening. The stress-strained state of the alloy upon cyclic loading can be described by the Hollomon equation with the cyclic strength coefficient K' and the cyclic strain-hardening exponent n' equal to 641 MPa and 0.066, respectively. The dependence of the number of cycles to fracture on the loading amplitude and its components (amplitudes of the plastic and elastic deformation) is described by a Basquin-Manson-Coffin equation with the parameters σ'/ E = 0.014, b =-0.123, ɛ'f= 178.65, and c =-1.677.

  4. Behavior of surface and corner cracks subjected to tensile and bending loads in Ti-6Al-4V alloy

    NASA Technical Reports Server (NTRS)

    Forman, Royce G.; Mettu, Sambi R.

    1990-01-01

    The behavior of part-through flaws with regard to failure under monotonic loading and their growth under fatigue loading was studied experimentally and analytically. Comparisons are made of experimental values of toughness obtained using surface and corner cracked specimens with those obtained using standard test specimens, and also experimental growth cycles were compared with numerical predictions using the NASA/FLAGRO computer program. Tests were conducted on various types of surface and corner cracks under tensile and bending loads. Room temperature lab air provided the test environment. The material used in this study was the Ti-6Al-4V alloy in the solution treated and aged (STA) and stress relieved condition. Detailed tabulation of the fracture toughness data and results of life prediction using the NASA/FLAGRO program are presented. Fatigue crack growth rates for the part-through cracked specimens are compared with a base curve fitted from the data obtained using standard specimens. The fatigue loading used in the crack growth testing was constant-amplitude sinusoidal type.

  5. Sustained load crack growth design data for Ti-6Al-4V titanium alloy tanks containing hydrazine

    NASA Technical Reports Server (NTRS)

    Lewis, J. C.; Kenny, J. T.

    1976-01-01

    Results are presented for an experimental study intended to provide sustained load crack growth (SLCG) data for Ti-6Al-4V titanium alloy tanks containing MIL-P-26536 hydrazine and refined hydrazine. Fracture mechanics data on crack growth threshold for heat-treated forgings, aged and unaged welds, and aged and unaged heat-affected zones (HAZ) are presented. All tests were made on uniaxially loaded fracture mechanics specimens involving part-through cracks, and an electrical discharge machined notch was used to start the crack. Fracture mechanics design curves of crack growth threshold stress intensity versus temperature are obtained for the temperature range 40-71 C. Major conclusions are that extreme susceptibility to SLCG in hydrazine is a universal property of unaged weld metal in Ti-6Al-4V titanium alloy of normal interstitial content, and that aging both weld metal and HAZ at 510 C for 4 hr after welding completely removes all susceptibility to SLCG induced by hydrazine, with less susceptibility to SLCG in refined hydrazine.

  6. Fracture behavior of quaternary Al-Li-Cu-Mg alloy under mixed mode I/III loading

    SciTech Connect

    Eswara Prasad, N.; Kamat, S.V.

    1995-07-01

    The fracture toughness under mixed-mode I/III loading conditions was evaluated for a quaternary 8090 Al-Li-Cu-Mg alloy in underaged and peak-aged conditions. The mixed-mode fracture behavior was found to be significantly different for the two aging conditions. Super-imposed mode III component lowered the fracture resistance of the alloy in underaged conditions, whereas it had no significant effect in peak-aged condition. The results obtained have been discussed in the light of the prevalent fracture processes, namely, transgranular shear and ductile intergranular fracture mechanisms. Further, these results are analyzed in terms of different fracture criteria and they were found to deviate significantly from those predicted by the energy release rate criterion.

  7. Quantitative analysis of morphology of the fracture surface AlMg6 alloy with consecutive dynamic and gigacycle loading

    NASA Astrophysics Data System (ADS)

    Oborin, Vladimir; Sokovikov, Mikhail; Bilalov, Dmitry; Naimark, Oleg

    2015-10-01

    In this paper we investigated the influence of consecutive dynamic and gigacycle fatigue loads on the lifetime of aluminum-magnesium alloy AlMg6. Preloading of samples was achieved during dynamic tensile tests in the split-Hopkinson bar device. Fatigue tests were conducted on Shimadzu USF-2000 ultrasonic fatigue testing machine. The New-View 5010 interferometer-profiler of high structural resolution (resolution of 0.1 nm) was used for qualitative fracture surface analysis, which provided the data allowing us to find correlation between mechanical properties and scale-invariant characteristics of damage induced roughness formed under dynamic and gigacycle fatigue loading conditions. Original form of the kinetic equation was proposed, which links the rate of the fatigue crack growth and the stress intensity factor using the scale invariant parameters of fracture surface roughness. The scale invariance characterizes the correlated behavior of multiscale damage provides the link of crack growth kinetics and the power exponent of the modified Paris law.

  8. Effects of Loading Type And Cavity Position On The Pattern Height In Micro-manufacturing of Al5083 Superplastic Alloy And Zr62Cu17Ni13Al8 Metallic Glass

    NASA Astrophysics Data System (ADS)

    Na, Young-Sang; Son, Seon-Cheon; Park, Kyu-Yeol; Lee, Jong-Hoon

    2009-11-01

    Vibrational micro-forming of pyramidal shape patterns was conducted for an Al superplastic alloy, Al 5083 and a Zr-based bulk metallic glass, Zr62Cu17Ni13Al8. A vibrational micro-forming system was specially designed for generating vibrational load by combining a PZT actuator with a signal generator. Si micro dies with wet-etched pyramidal patterns were used as master dies for vibrational micro-forming. The micro-formed pattern height was increasing with increasing the frequency of the vibrational load. In particular, the vibrationally-microformed pattern height is similar or even higher than the statically-microformed pattern height when the load frequency exceeded about 125 kHz. It was also observed that the crystal grains affect the surface quality of the microformed pattern and the distribution of the pattern height in the die cavity array.

  9. HIRREM™: a noninvasive, allostatic methodology for relaxation and auto-calibration of neural oscillations.

    PubMed

    Gerdes, Lee; Gerdes, Peter; Lee, Sung W; H Tegeler, Charles

    2013-03-01

    Disturbances of neural oscillation patterns have been reported with many disease states. We introduce methodology for HIRREM™ (high-resolution, relational, resonance-based electroencephalic mirroring), also known as Brainwave Optimization™, a noninvasive technology to facilitate relaxation and auto-calibration of neural oscillations. HIRREM is a precision-guided technology for allostatic therapeutics, intended to help the brain calibrate its own functional set points to optimize fitness. HIRREM technology collects electroencephalic data through two-channel recordings and delivers a series of audible musical tones in near real time. Choices of tone pitch and timing are made by mathematical algorithms, principally informed by the dominant frequency in successive instants of time, to permit resonance between neural oscillatory frequencies and the musical tones. Relaxation of neural oscillations through HIRREM appears to permit auto-calibration toward greater hemispheric symmetry and more optimized proportionation of regional spectral power. To illustrate an application of HIRREM, we present data from a randomized clinical trial of HIRREM as an intervention for insomnia (n = 19). On average, there was reduction of right-dominant temporal lobe high-frequency (23-36 Hz) EEG asymmetry over the course of eight successive HIRREM sessions. There was a trend for correlation between reduction of right temporal lobe dominance and magnitude of insomnia symptom reduction. Disturbances of neural oscillation have implications for both neuropsychiatric health and downstream peripheral (somatic) physiology. The possibility of noninvasive optimization for neural oscillatory set points through HIRREM suggests potentially multitudinous roles for this technology. Research is currently ongoing to further explore its potential applications and mechanisms of action.

  10. Biaxial flexural strength and phase transformation of Ce-TZP/Al2O3 and Y-TZP core materials after thermocycling and mechanical loading

    PubMed Central

    Bankoğlu Güngör, Merve; Aydın, Cemal; Karakoca Nemli, Seçil; Turhan Bal, Bilge; Tıraş, Tülay

    2014-01-01

    PURPOSE The purpose of the present study was to evaluate the effect of thermocycling and mechanical loading on the biaxial flexural strength and the phase transformation of one Ce-TZP/Al2O3 and two Y-TZP core materials. MATERIALS AND METHODS Thirty disc-shaped specimens were obtained from each material. The specimens were randomly divided into three groups (control, thermocycled, and mechanically loaded). Thermocycling was subjected in distilled water for 10000 cycles. Mechanical loading was subjected with 200 N loads at a frequency of 2 Hz for 100000 times. The mean biaxial flexural strength and phase transformation of the specimens were tested. The Weibull modulus, characteristic strength, 10%, 5% and 1% probabilities of failure were calculated using the biaxial flexural strength data. RESULTS The characteristic strengths of Ce-TZP/Al2O3 specimens were significantly higher in all groups compared with the other tested materials (P<.001). Statistical results of X-ray diffraction showed that thermocycling and mechanical loading did not affect the monoclinic phase content of the materials. According to Raman spectroscopy results, at the same point and the same material, mechanical loading significantly affected the phase fraction of all materials (P<.05). CONCLUSION It was concluded that thermocycling and mechanical loading did not show negative effect on the mean biaxial strength of the tested materials. PMID:25006387

  11. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales.

    PubMed

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A; Clausen, Bjørn; Pu, Chao; Li, Lin; Gao, Yanfei; Liaw, Peter K

    2016-01-01

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 °C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix and elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 °C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. The study contributes to further understanding of load-partitioning characteristics in multiphase materials. PMID:26979660

  12. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales

    DOE PAGES

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A.; Clausen, Bjorn; Pu, Chao; Li, Lin; Gao, Yanfei; Liaw, Peter K.

    2016-03-16

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix andmore » elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. Furthermore, the study contributes to further understanding of load-partitioning characteristics in multiphase materials.« less

  13. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales

    PubMed Central

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A.; Clausen, Bjørn; Pu, Chao; Li, Lin; Gao, Yanfei; Liaw, Peter K.

    2016-01-01

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 °C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix and elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 °C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. The study contributes to further understanding of load-partitioning characteristics in multiphase materials. PMID:26979660

  14. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales

    NASA Astrophysics Data System (ADS)

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A.; Clausen, Bjørn; Pu, Chao; Li, Lin; Gao, Yanfei; Liaw, Peter K.

    2016-03-01

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 °C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix and elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 °C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. The study contributes to further understanding of load-partitioning characteristics in multiphase materials.

  15. Effect of the Initial Load Parameters on the K-shell Output of Al Planar Wire Arrays Operating in the Microsecond Implosion Regime

    SciTech Connect

    Shishlov, A.; Chaikovsky, S.; Fedunin, A.; Fursov, F.; Kokshenev, V.; Kurmaev, N.; Labetsky, A.; Oreshkin, V.; Rousskikh, A.; Labetskaya, N.

    2009-01-21

    A set of microsecond implosion experiments was carried on the GIT-12 generator to study the radiative performance of Al planar wire arrays. The load parameters such as a wire diameter, a gap between the wires, the number of wires, and the total planar wire mass and width were varied during the experiments, however the implosion time and the peak implosion current were almost the same for all load configurations. This ensured equal energy deposition to the plasma due to kinetic mechanisms for all load configurations. Two implosion regimes with the implosion times of 1050 ns and 850 ns were investigated. The experimental data on the K-shell radiation yield and power at varying load parameters are presented.

  16. Quantifying Chronic Stress Exposure for Cumulative Risk Assessment: Lessons Learned from a Case Study of Allostatic Load

    EPA Science Inventory

    Although multiple methods of quantifying environmental chemical exposures have been validated for use in human health risk assessment, quantifying chronic stress exposure is more challenging. Stress is a consequence of perceiving an “exposure” (e.g., violence, poverty) as more th...

  17. Cumulative Socioeconomic Status Risk, Allostatic Load, and Adjustment: A Prospective Latent Profile Analysis with Contextual and Genetic Protective Factors

    ERIC Educational Resources Information Center

    Brody, Gene H.; Yu, Tianyi; Chen, Yi-Fu; Kogan, Steven M.; Evans, Gary W.; Beach, Steven R. H.; Windle, Michael; Simons, Ronald L.; Gerrard, Meg; Gibbons, Frederick X.; Philibert, Robert A.

    2013-01-01

    The health disparities literature has identified a common pattern among middle-aged African Americans that includes high rates of chronic disease along with low rates of psychiatric disorders despite exposure to high levels of cumulative socioeconomic status (SES) risk. The current study was designed to test hypotheses about the developmental…

  18. Removal of fluoride from drinking water using tea waste loaded with Al/Fe oxides: A novel, safe and efficient biosorbent

    NASA Astrophysics Data System (ADS)

    Cai, Hui-mei; Chen, Gui-jie; Peng, Chuan-yi; Zhang, Zheng-zhu; Dong, Yang-yang; Shang, Guang-zhi; Zhu, Xiao-hui; Gao, Hong-jian; Wan, Xiao-chun

    2015-02-01

    A low-cost and highly efficient biosorbent was prepared by loading Al/Fe oxides onto tea waste and was tested for the ability to remove fluoride from drinking water. Key factors, including adsorbent dosage, initial fluoride concentration, contact time and initial pH of the biosorbent, were investigated. It was found that the solution pH played an important role in the removal of fluoride. The biosorbent combinations Tea-Al or Tea-Al-Fe could reduce the fluoride concentration to below 1.5 mg/L in the drinking water, a level which meets the drinking water standard recommended by the World Health Organization (WHO). In addition, the residual concentrations of Al and Fe in the drinking water after Tea-Al-Fe treatment were below the standards set by WHO when treatment was conducted at pH values ranging from 5.0 to 10.0. The experimental data were analyzed using two-parameter theoretical models. The maximum fluoride adsorption capacities for the original tea, Tea-Fe, Tea-Al and Tea-Al-Fe biosorbents were 3.83, 10.47, 13.79 and 18.52 mg/g, respectively. These findings demonstrate the suitability of a prepared biosorbent based on tea waste for the removal of fluoride from drinking water.

  19. Effects of Potassium loading and thermal aging on K/Pt/Al2O3 high-temperature lean NOx trap catalysts

    SciTech Connect

    Luo, Jinyong; Gao, Feng; Kim, Do Heui; Peden, Charles HF

    2014-03-31

    The effects of K loading and thermal aging on the structural properties and high temperature performance of Pt/K/Al2O3 lean NOx trap (LNT) catalysts were investigated using in situ X-ray diffraction (XRD), temperature-programmed decomposition/desorption of NOx (NOx-TPD), transmission electron microscopy (TEM), NO oxidation and NOx storage tests. In situ XRD results demonstrate that KNO3 becomes extremely mobile on the Al2O3 surface, and experiences complex transformations between orthorhombic and rhombohedral structures, accompanied by sintering, melting and thermal decomposition upon heating. NOx storage results show an optimum K loading around 10% for the best performance at high temperatures. At lower K loadings where the majority of KNO3 stays as a surface layer, the strong interaction between KNO3 and Al2O3 promotes KNO3 decomposition and deteriorates high-temperature performance. At K loadings higher than 10%, the performance drop is not caused by NOx diffusion limitations as for the case of barium-based LNTs, but rather from the blocking of Pt sites by K species, which adversely affects NO oxidation. Thermal aging at 800 ºC severely deactivates the Pt/K/Al2O3 catalysts due to Pt sintering. However, in the presence of potassium, some Pt remains in a dispersed and oxidized form. These Pt species interact strongly with K and, therefore, do not sinter. After a reduction treatment, these Pt species remain finely dispersed, contributing to a partial recovery of NOx storage performance.

  20. Crack growth in a ductile-phase-toughened Nb/Nb[sub 3]Al in situ intermetallic composite under monotonic and cyclic loading

    SciTech Connect

    Murugesh, L.; Venkateswara Rao, K.T.; Ritchie, R.O. . Dept. of Materials Science and Mineral Engineering)

    1993-10-15

    One approach to improving the ductility and toughness of brittle solids is to incorporate a ductile phase into the brittle matrix in order to impede the extension of incipient cracks. In this regard, recent word has shown that niobium can provide significant ductile-phase toughening in several intermetallic composites via crack bridging, plastic stretching and interfacial debonding mechanisms; however, under cyclic loading the role of the ductile phase appears to be less effective. Accordingly, the purpose of the current study is to examine the effect of the addition of ductile Nb phase on fracture and fatigue behavior in an equiaxed Nb/Nb[sub 3]Al in situ composite; results are compared with behavior in unreinforced Nb[sub 3]Al and Nb to determine possible mechanisms of crack propagation in Nb-toughened Nb[sub 3]Al intermetallic composites.

  1. The study of crack resistance of TiAlN coatings under mechanical loading and thermal cycle testing

    SciTech Connect

    Akulinkin, Alexandr Shugurov, Artur Sergeev, Viktor; Panin, Alexey; Cheng, C.-H.

    2015-10-27

    The effect of preliminary ion bombardment of 321 stainless steel substrate on crack resistance of TiAlN coatings at uniaxial tension and thermal cycling is studied. The ion-beam treatment of the substrate is shown to substantially improve the adhesion strength of the coatings that prevents their delamination and spalling under uniaxial tension. The resistance to crack propagation and spalling by the thermal shock is higher in the TiAlN coating deposited onto the substrate subjected to Ti ion bombardment as compared to that in the TiAlN coating deposited onto the initial substrate.

  2. Strain-based fatigue data for Ti-6Al-4V ELI under fully-reversed and mean strain loads.

    PubMed

    Carrion, Patricio E; Shamsaei, Nima

    2016-06-01

    This article presents the experimental data supporting the study to obtain the mean strain/stress effects on the fatigue behavior of Ti-6Al-4V ELI. A series of strain-controlled fatigue experiments on Ti-6Al-4V ELI were performed at four strain ratios (-1, -0.5, 0, and 0.5). Two types of data are included for each specimen. These are the hysteresis stress-strain responses for the cycle in a log10 increment, and the maximum and minimum stress-strain responses for each cycle. Fatigue lives are also reported for all the experiments.

  3. Effect of an allostatic modulator on stress blood indicators and meat quality of commercial young bulls in Mexico.

    PubMed

    Rubio Lozano, M S; Méndez Medina, R D; Reyes Mayorga, K; Rubio García, M E; Ovando, M A; Ngapo, T M; Galindo Maldonado, F A

    2015-07-01

    To assess the effect of an allostatic modulator (AM) on stress blood indicators and meat quality traits, the feed of 80 non-castrated 18-20 month-old bulls was supplemented with 10 g/day of an AM for 30 days before slaughter. Another 80 bulls served as control animals. The AM was comprised of ascorbic acid, acetoxybenzoic acid and sodium and potassium chloride. Blood samples were taken at slaughter for analyses of hematocrit value, erythrocyte and leukocyte counts, and glucose, lactate and cortisol concentrations. Post-mortem measures of meat color and pH were made at 24h and color, shear force and cooking loss on meat from 20 animals at 28 days. The AM supplementation resulted in lower hematocrit value, erythrocyte count and glucose level (P<0.05), higher a* (P<0.0001) and b* (P<0.0001) at 24h and lower b* (P<0.05) at 28 days. Thus AM treatment improved some stress blood indicators and meat color and therefore merits further investigation. PMID:25817802

  4. Effect of an allostatic modulator on stress blood indicators and meat quality of commercial young bulls in Mexico.

    PubMed

    Rubio Lozano, M S; Méndez Medina, R D; Reyes Mayorga, K; Rubio García, M E; Ovando, M A; Ngapo, T M; Galindo Maldonado, F A

    2015-07-01

    To assess the effect of an allostatic modulator (AM) on stress blood indicators and meat quality traits, the feed of 80 non-castrated 18-20 month-old bulls was supplemented with 10 g/day of an AM for 30 days before slaughter. Another 80 bulls served as control animals. The AM was comprised of ascorbic acid, acetoxybenzoic acid and sodium and potassium chloride. Blood samples were taken at slaughter for analyses of hematocrit value, erythrocyte and leukocyte counts, and glucose, lactate and cortisol concentrations. Post-mortem measures of meat color and pH were made at 24h and color, shear force and cooking loss on meat from 20 animals at 28 days. The AM supplementation resulted in lower hematocrit value, erythrocyte count and glucose level (P<0.05), higher a* (P<0.0001) and b* (P<0.0001) at 24h and lower b* (P<0.05) at 28 days. Thus AM treatment improved some stress blood indicators and meat color and therefore merits further investigation.

  5. Size Effect on Deformation Mode in Micron-Sized Ti-5Al Single Crystal Loaded Along [2 /line 1 /line 1 0] and [0001

    NASA Astrophysics Data System (ADS)

    Xiao, Lin; Yu, Qian; Sun, Qiaoyan; Sun, Jun

    Free-standing sub-micron Ti-5Al single crystal square pillars were fabricated along [2 /line 1 /line 1 0] double slip and [0001] twinning orientations using FIB fabrication processes. Samples in range of 0.4 to 2.0µm were compressed. The yield stress increases much higher than their bulk counterpart as the specimen width decreases. The tendency of "smaller is stronger" is displayed in Ti-5Al single crystals loaded along [2 /line 1 /line 1 0] and [0001] orientations. The number of slip systems is restricted by specimen physical size as it declines from 2µm to 0.5µm, when the specimens were subjected to double slip loading. Meanwhile, when sample size is less than 1.0µm, micro-pillars along twinning orientation have to compensate the incomplete twinning deformation via shearing due to geometrical restriction and dislocation starvation effects. This variation of deformation mode could be attributed to the starvation effect of dislocations.

  6. Combined Near and Far Field High Energy Diffraction Microscopy Dataset for Ti-7Al Tensile Specimen Elastically Loaded In Situ

    DOE Data Explorer

    Turner, Todd J.; Shade, Paul A; Bernier, Joel V.; Li, Shiu Fai; Schuren, Jay C.; Lind, Jonathan F.; Lienert, Ulrich; Kenesei, Peter; Suter, Robert; Blank, Basil; Almer, Jonathan

    2016-01-01

    We present both near-field HEDM data that maps out the grain morphology and intragranular crystallographic orientations and far-field HEDM data that provides the grain centroid, grain average crystallographic orientation, and grain average elastic strain tensor for each grain. Finally, we provide a finite element mesh that can be utilized to simulate deformation in the volume of this Ti-7Al specimen.

  7. Gd-Al co-doped mesoporous silica nanoparticles loaded with Ru(bpy)₃²⁺ as a dual-modality probe for fluorescence and magnetic resonance imaging.

    PubMed

    Zhang, Dan; Gao, Ai; Xu, Yang; Yin, Xue-Bo; He, Xi-Wen; Zhang, Yu-Kui

    2014-09-21

    Mesoporous silica nanoparticles (MSNs) were co-doped with Gd(3+) and Al(3+) and then loaded with Ru(bpy)3(2+) by ion-exchange to prepare Ru/Gd-Al@MSNs. The as-prepared Ru/Gd-Al@MSNs were applied as contrast agents for in vivo fluorescence and magnetic resonance (MR) dual-modality imaging with a mouse as a model. The effects of Al(3+) and MSNs on longitudinal relaxivity (r1) and fluorescence were investigated using a series of Gd-containing silica nanoparticles, including Gd@MSNs, Gd-Al@MSNs, and Ru/Gd-Al@nonporous silica nanoparticles. Co-doping with Al(3+) improved the loading of Gd(3+); the mesoporous structure improved the water exchange rate. The improvement enhanced the MR imaging efficiency of the Ru/Gd-Al@MSN probe. A higher relaxivity (19.2 mM(-1) s(-1)) was observed compared to that from a commercial contrast agent, Gd-diethylene triamine pentaacetic acid (Gd-DTPA). Importantly, the mesoporous structure provided a large specific surface area for the loading of Ru(bpy)3(2+) by a simple ion-exchange procedure. Intense red fluorescence was observed from Ru/Gd-Al@MSN probes. The versatility of Ru/Gd-Al@MSNs for dual-modality imaging was demonstrated using in vivo fluorescence imaging and T1-weighted MR imaging with a mouse model. The nanoparticles are biocompatible and may be attractive for clinical applications.

  8. The effect of coating/substrate interface curvature on fracture of Si-Al-N coatings subjected to mechanical loading

    NASA Astrophysics Data System (ADS)

    Shugurov, Artur

    2015-10-01

    The effect of curvature of the film/substrate interface on the fracture mechanisms of Si-Al-N coatings on Cu substrates subjected to uniaxial tension and alternating bending is studied. Local interface curvature due to substrate surface roughening caused by its plastic deformation in the course of the uniaxial tension is shown to have a profound effect on their delamination and buckling. Interface curvature induced by specimen bending promotes kinking of through-the-coating cracks at the interface that is followed by delamination and spalling of the coatings.

  9. Increases in mature brain-derived neurotrophic factor protein in the frontal cortex and basal forebrain during chronic sleep restriction in rats: possible role in initiating allostatic adaptation.

    PubMed

    Wallingford, J K; Deurveilher, S; Currie, R W; Fawcett, J P; Semba, K

    2014-09-26

    Chronic sleep restriction (CSR) has various negative consequences on cognitive performance and health. Using a rat model of CSR that uses alternating cycles of 3h of sleep deprivation (using slowly rotating activity wheels) and 1h of sleep opportunity continuously for 4 days ('3/1' protocol), we previously observed not only homeostatic but also allostatic (adaptive) sleep responses to CSR. In particular, non-rapid eye movement sleep (NREMS) electroencephalogram (EEG) delta power, an index of sleep intensity, increased initially and then declined gradually during CSR, with no rebound during a 2-day recovery period. To study underlying mechanisms of these allostatic responses, we examined the levels of brain-derived neurotrophic factor (BDNF), which is known to regulate NREMS EEG delta activity, during the same CSR protocol. Mature BDNF protein levels were measured in the frontal cortex and basal forebrain, two brain regions involved in sleep and EEG regulation, and the hippocampus, using Western blot analysis. Adult male Wistar rats were housed in motorized activity wheels, and underwent the 3/1 CSR protocol for 27 h, for 99 h, or for 99 h followed by 24h of recovery. Additional rats were housed in either locked wheels (locked wheel controls [LWCs]) or unlocked wheels that rats could rotate freely (wheel-running controls [WRCs]). BDNF levels did not differ between WRC and LWC groups. BDNF levels were increased, compared to the control levels, in all three brain regions after 27 h, and were increased less strongly after 99 h, of CSR. After 24h of recovery, BDNF levels were at the control levels. This time course of BDNF levels parallels the previously reported changes in NREMS delta power during the same CSR protocol. Changes in BDNF protein levels in the cortex and basal forebrain may be part of the molecular mechanisms underlying allostatic sleep responses to CSR.

  10. A model for homeopathic remedy effects: low dose nanoparticles, allostatic cross-adaptation, and time-dependent sensitization in a complex adaptive system

    PubMed Central

    2012-01-01

    Background This paper proposes a novel model for homeopathic remedy action on living systems. Research indicates that homeopathic remedies (a) contain measurable source and silica nanoparticles heterogeneously dispersed in colloidal solution; (b) act by modulating biological function of the allostatic stress response network (c) evoke biphasic actions on living systems via organism-dependent adaptive and endogenously amplified effects; (d) improve systemic resilience. Discussion The proposed active components of homeopathic remedies are nanoparticles of source substance in water-based colloidal solution, not bulk-form drugs. Nanoparticles have unique biological and physico-chemical properties, including increased catalytic reactivity, protein and DNA adsorption, bioavailability, dose-sparing, electromagnetic, and quantum effects different from bulk-form materials. Trituration and/or liquid succussions during classical remedy preparation create “top-down” nanostructures. Plants can biosynthesize remedy-templated silica nanostructures. Nanoparticles stimulate hormesis, a beneficial low-dose adaptive response. Homeopathic remedies prescribed in low doses spaced intermittently over time act as biological signals that stimulate the organism’s allostatic biological stress response network, evoking nonlinear modulatory, self-organizing change. Potential mechanisms include time-dependent sensitization (TDS), a type of adaptive plasticity/metaplasticity involving progressive amplification of host responses, which reverse direction and oscillate at physiological limits. To mobilize hormesis and TDS, the remedy must be appraised as a salient, but low level, novel threat, stressor, or homeostatic disruption for the whole organism. Silica nanoparticles adsorb remedy source and amplify effects. Properly-timed remedy dosing elicits disease-primed compensatory reversal in direction of maladaptive dynamics of the allostatic network, thus promoting resilience and recovery from

  11. Time-of-day modulation of homeostatic and allostatic sleep responses to chronic sleep restriction in rats.

    PubMed

    Deurveilher, S; Rusak, B; Semba, K

    2012-06-15

    To study sleep responses to chronic sleep restriction (CSR) and time-of-day influences on these responses, we developed a rat model of CSR that takes into account the polyphasic sleep patterns in rats. Adult male rats underwent cycles of 3 h of sleep deprivation (SD) and 1 h of sleep opportunity (SO) continuously for 4 days, beginning at the onset of the 12-h light phase ("3/1" protocol). Electroencephalogram (EEG) and electromyogram (EMG) recordings were made before, during, and after CSR. During CSR, total sleep time was reduced by ∼60% from baseline levels. Both rapid eye movement sleep (REMS) and non-rapid eye movement sleep (NREMS) during SO periods increased initially relative to baseline and remained elevated for the rest of the CSR period. In contrast, NREMS EEG delta power (a measure of sleep intensity) increased initially, but then declined gradually, in parallel with increases in high-frequency power in the NREMS EEG. The amplitude of daily rhythms in NREMS and REMS amounts was maintained during SO periods, whereas that of NREMS delta power was reduced. Compensatory responses during the 2-day post-CSR recovery period were either modest or negative and gated by time of day. NREMS, REMS, and EEG delta power lost during CSR were not recovered by the end of the second recovery day. Thus the "3/1" CSR protocol triggered both homeostatic responses (increased sleep amounts and intensity during SOs) and allostatic responses (gradual decline in sleep intensity during SOs and muted or negative post-CSR sleep recovery), and both responses were modulated by time of day.

  12. Time-of-day modulation of homeostatic and allostatic sleep responses to chronic sleep restriction in rats.

    PubMed

    Deurveilher, S; Rusak, B; Semba, K

    2012-06-15

    To study sleep responses to chronic sleep restriction (CSR) and time-of-day influences on these responses, we developed a rat model of CSR that takes into account the polyphasic sleep patterns in rats. Adult male rats underwent cycles of 3 h of sleep deprivation (SD) and 1 h of sleep opportunity (SO) continuously for 4 days, beginning at the onset of the 12-h light phase ("3/1" protocol). Electroencephalogram (EEG) and electromyogram (EMG) recordings were made before, during, and after CSR. During CSR, total sleep time was reduced by ∼60% from baseline levels. Both rapid eye movement sleep (REMS) and non-rapid eye movement sleep (NREMS) during SO periods increased initially relative to baseline and remained elevated for the rest of the CSR period. In contrast, NREMS EEG delta power (a measure of sleep intensity) increased initially, but then declined gradually, in parallel with increases in high-frequency power in the NREMS EEG. The amplitude of daily rhythms in NREMS and REMS amounts was maintained during SO periods, whereas that of NREMS delta power was reduced. Compensatory responses during the 2-day post-CSR recovery period were either modest or negative and gated by time of day. NREMS, REMS, and EEG delta power lost during CSR were not recovered by the end of the second recovery day. Thus the "3/1" CSR protocol triggered both homeostatic responses (increased sleep amounts and intensity during SOs) and allostatic responses (gradual decline in sleep intensity during SOs and muted or negative post-CSR sleep recovery), and both responses were modulated by time of day. PMID:22492816

  13. The stress of growing old: sex- and season-specific effects of age on allostatic load in wild grey mouse lemurs.

    PubMed

    Hämäläinen, Anni; Heistermann, Michael; Kraus, Cornelia

    2015-08-01

    Chronic stress [i.e. long-term elevation of glucocorticoid (GC) levels] and aging have similar, negative effects on the functioning of an organism. Aged individuals' declining ability to regulate GC levels may therefore impair their ability to cope with stress, as found in humans. The coping of aged animals with long-term natural stressors is virtually unstudied, even though the ability to respond appropriately to stressors is likely integral to the reproduction and survival of wild animals. To assess the effect of age on coping with naturally fluctuating energetic demands, we measured stress hormone output via GC metabolites in faecal samples (fGCM) of wild grey mouse lemurs (Microcebus murinus) in different ecological seasons. Aged individuals were expected to exhibit elevated fGCM levels under energetically demanding conditions. In line with this prediction, we found a positive age effect in the dry season, when food and water availability are low and mating takes place, suggesting impaired coping of aged wild animals. The age effect was significantly stronger in females, the longer-lived sex. Body mass of males but not females correlated positively with fGCM in the dry season. Age or body mass did not influence fGCM significantly in the rainy season. The sex- and season-specific predictors of fGCM may reflect the differential investment of males and females into reproduction and longevity. A review of prior research indicates contradictory aging patterns in GC regulation across and even within species. The context of sampling may influence the likelihood of detecting senescent declines in GC functioning.

  14. Use of an allostatic neurotechnology by adolescents with postural orthostatic tachycardia syndrome (POTS) is associated with improvements in heart rate variability and changes in temporal lobe electrical activity.

    PubMed

    Fortunato, John E; Tegeler, Catherine L; Gerdes, Lee; Lee, Sung W; Pajewski, Nicholas M; Franco, Meghan E; Cook, Jared F; Shaltout, Hossam A; Tegeler, Charles H

    2016-03-01

    Autonomic dysregulation and heterogeneous symptoms characterize postural orthostatic tachycardia syndrome (POTS). This study evaluated the effect of high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM(®)), a noninvasive, allostatic neurotechnology for relaxation and auto-calibration of neural oscillations, on heart rate variability, brain asymmetry, and autonomic symptoms, in adolescents with POTS. Seven subjects with POTS (three males, ages 15-18) underwent a median of 14 (10-16) HIRREM sessions over 13 (8-17) days. Autonomic function was assessed from 10-min continuous heart rate and blood pressure recordings, pre- and post-HIRREM. One-minute epochs of temporal high-frequency (23-36 Hz) brain electrical activity data (T3 and T4, eyes closed) were analyzed from baseline HIRREM assessment and subsequent sessions. Subjects rated autonomic symptoms before and after HIRREM. Four of seven were on fludrocortisone, which was stopped before or during their sessions. Heart rate variability in the time domain (standard deviation of the beat-to-beat interval) increased post-HIRREM (mean increase 51%, range 10-143, p = 0.03), as did baroreflex sensitivity (mean increase in high-frequency alpha 65%, range -6 to 180, p = 0.05). Baseline temporal electrical asymmetry negatively correlated with change in asymmetry from assessment to the final HIRREM session (p = 0.01). Summed high-frequency amplitudes at left and right temporal lobes decreased a median of 3.8 μV (p = 0.02). There was a trend for improvements in self-reported symptoms related to the autonomic nervous system. Use of HIRREM was associated with reduced sympathetic bias in autonomic cardiovascular regulation, greater symmetry and reduced amplitudes in temporal lobe high-frequency electrical activity, and a trend for reduced autonomic symptoms. Data suggest the potential for allostatic neurotechnology to facilitate increased flexibility in autonomic cardiovascular regulation, possibly

  15. The Influences of Grain Size and Morphology on the Hot Tearing Susceptibility, Contraction, and Load Behaviors of AA7050 Alloy Inoculated with Al-5Ti-1B Master Alloy

    NASA Astrophysics Data System (ADS)

    Li, Y.; Bai, Q. L.; Liu, J. C.; Li, H. X.; Du, Q.; Zhang, J. S.; Zhuang, L. Z.

    2016-08-01

    The influences of grain size and morphology on the hot tearing susceptibility of AA7050 alloy inoculated with Al-5Ti-1B master alloy were investigated by the authors. It was found that with the optimal addition of Al-5Ti-1B, coarse columnar grains were transformed into fine globular equiaxed grains. Moreover, due to the changes of grain size and morphology, the hot tearing susceptibility was decreased remarkably, which was attributed to the lower mechanical coherency temperature, better feeding ability, lower strain, and strain rate imposed to the mushy zone and more meandering propagation paths of hot tears. But the excess Al-5Ti-1B additions did not affect the grain structure, and greatly promoted hot tearing susceptibility due to the agglomerations of secondary phase particles from Al-5Ti-1B master alloy. The formation of massive secondary phases at grain boundaries hindered the interdendritic liquid flow and substantially deteriorated the feeding ability in the last stage of solidification. Meanwhile, TiB2 agglomerates would also act as stress raisers and cause the formation of voids. The contraction and load behaviors of AA7050 alloy influenced by grain size and morphology would be explored and connected with the hot tearing occurrence in this study.

  16. Microstructure studies of air-plasma-spray-deposited CoNiCrAlY coatings before and after thermal cyclic loading for high-temperature application

    NASA Astrophysics Data System (ADS)

    Kumar, Dipak; Pandey, K. N.; Das, Dipak Kumar

    2016-08-01

    In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying (APS) techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) were used to investigate the phases and microstructure of the as-sprayed, APS-deposited CoNiCrAlY bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of the γ/γ'-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in CoNiCrAlY bond-coatings with excellent thermal cyclic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.

  17. Load cell

    DOEpatents

    Spletzer, B.L.

    1998-12-15

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components. 16 figs.

  18. Load cell

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs which can be combined to determine any one of the six general load components.

  19. Load cell

    DOEpatents

    Spletzer, Barry L.

    1998-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components.

  20. Influence of early life stress on later hypothalamic–pituitary–adrenal axis functioning and its covariation with mental health symptoms: A study of the allostatic process from childhood into adolescence

    PubMed Central

    Essex, Marilyn J.; Shirtcliff, Elizabeth A.; Burk, Linnea R.; Ruttle, Paula L.; Klein, Marjorie H.; Slattery, Marcia J.; Kalin, Ned H.; Armstrong, Jeffrey M.

    2012-01-01

    The hypothalamic-pituitary-adrenal (HPA) axis is a primary mechanism in the allostatic process through which early life stress (ELS) contributes to disease. Studies of the influence of ELS on children’s HPA axis functioning have yielded inconsistent findings. To address this issue, the present study considers multiple types of ELS (maternal depression, paternal depression, and family expressed anger), mental health symptoms, and two components of HPA functioning (trait-like and epoch-specific activity) in a long-term prospective community study of 357 children. ELS was assessed during the infancy and preschool periods; mental health symptoms and cortisol were assessed at child ages 9, 11, 13, and 15 years. A 3-level hierarchical linear model addressed questions regarding the influences of ELS on HPA functioning and its co-variation with mental health symptoms. ELS influenced trait-like cortisol level and slope, with both hyper- and hypo-arousal evident depending on type of ELS. Further, type(s) of ELS influenced co-variation of epoch-specific HPA functioning and mental health symptoms, with a tighter coupling of HPA alterations with symptom severity among children exposed previously to ELS. Results highlight the importance of examining multiple types of ELS and dynamic HPA functioning in order to capture the allostatic process unfolding across the transition into adolescence. PMID:22018080

  1. Osseointegration of loaded dental implant with KrF laser hydroxylapatite films on Ti6Al4V alloy by minipigs

    NASA Astrophysics Data System (ADS)

    Dostalova, Tatjana; Himmlova, Lucia; Jelinek, Miroslav; Grivas, Christos

    2001-04-01

    This study was performed with the objective of evaluating osseointegration of titanium alloy Ti6Al4V dental implants coated with hydroxylapatite (HA) deposited by a KrF laser. For this a KrF excimer laser and stainless-steel deposition chamber were used. The thickness of the HA films was approximately 1 micrometers . IN this investigation experimental animals minipigs were used; the implants were placed vertically into the lower jaw. After 14 weeks of unloaded osseointegration, metal-ceramic crowns were inserted and, at the same time, fluorescent solution was injected into the experimental animals. Six months after insertion of crowns the animals were sacrificed. The vertical position of the implants was checked by a radiograph. Microscopic sections were cut and ground, and the sections were examined under polarized and fluorescent light using a microscope with a charge coupled device camera. The six month long osseointegration in the lower jaw has confirmed the presence of newly formed bone around all the implants. In the experimental group, which had a laser-deposited coating, the layer of fibrous connective tissue was seen only randomly. In the control group (titanium implant without a cover) the fibrous connective tissue between the implant and the newly formed bone was observed more frequently, but this difference was not significant.

  2. Cyclic Deformation Response of β-Annealed Ti-5Al-5V-5Mo-3Cr Alloy Under Compressive Loading Conditions

    NASA Astrophysics Data System (ADS)

    Huang, Jun; Wang, Zhirui; Zhou, Jie

    2011-09-01

    This article reports the cyclic deformation behavior of the β-annealed metastable Ti-5Al-5V-5Mo-3Cr (Ti-5553) alloy under the condition of pure compressive fatigue stress. The following three aspects, namely, the mechanical response, the surface morphology evolution, and the dislocation structures, were systematically investigated. Under all testing conditions, the material demonstrated cyclic softening in the initial cycles followed by saturation. The progressive observation of surface morphology at fixed locations, but after different numbers of cycles, elucidated typical planar slip behavior and the early appearance of fatigue microcracks, which were found often to be induced by the highly localized planar slip bands. The transmission electron microscopy (TEM) study revealed dislocation annihilation upon cycling, i.e., the reduction of dislocation density as well as the simplification of dislocation configurations. In addition, detwinning and changed twin boundary structures upon cycling were also detected. Such activities, together with the intersection of coherent ω precipitates by moving dislocations, are considered to be responsible for the initial softening, whereas the dislocation dipole flip-flop mechanism is presumably responsible for the cyclic saturation behavior. An attempt was made to explain the strain-localized planar slip behavior by considering the stacking fault energy (SFE) as well as the free-electron-to-atom ( e/ a) ratio. The nanoscaled ω and α precipitation in the β matrix may also contribute to the planar slip behavior. The effect of the microstructure in the as-received material was also analyzed for the strain localization and planar-slip mode.

  3. RNAi: RISC gets loaded.

    PubMed

    Preall, Jonathan B; Sontheimer, Erik J

    2005-11-18

    When an siRNA or miRNA proceeds through the RNA-induced silencing complex assembly pathway, only one of the two approximately 21-nucleotide RNA strands survives in the final, active complex. In this issue of Cell, Matranga et al. (2005) and Rand et al. (2005) reveal the fate of the rejected passenger siRNA strand. Additionally, Gregory et al. (2005) define a heterotrimeric complex from humans that appears to execute dsRNA loading, strand selection, and target mRNA cleavage activities.

  4. Chitosan film loaded with silver nanoparticles-sorbent for solid phase extraction of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II).

    PubMed

    Djerahov, Lubomir; Vasileva, Penka; Karadjova, Irina; Kurakalva, Rama Mohan; Aradhi, Keshav Krishna

    2016-08-20

    The present study describes the ecofriendly method for the preparation of chitosan film loaded with silver nanoparticles (CS-AgNPs) and application of this film as efficient sorbent for separation and enrichment of Al(III), Cd(II), Cu(II), Co(II), Fe(III), Ni(II), Pb(II) and Zn(II). The stable CS-AgNPs colloid was prepared by dispersing the AgNPs sol in chitosan solution at appropriate ratio and further used to obtain a cast film with very good stability under storage and good mechanical strength for easy handling in aqueous medium. The incorporation of AgNPs in the structure of CS film and interaction between the polymer matrix and nanoparticles were confirmed by UV-vis and FTIR spectroscopy. The homogeneously embedded AgNPs (average diameter 29nm, TEM analysis) were clearly observed throughout the film by SEM. The CS-AgNPs nanocomposite film shows high sorption activity toward trace metals under optimized chemical conditions. The results suggest that the CS-AgNPs nanocomposite film can be feasibly used as a novel sorbent material for solid-phase extraction of metal pollutants from surface waters.

  5. Influences of Al particles on the microstructure and property of electrodeposited Ni-Al composite coatings

    NASA Astrophysics Data System (ADS)

    Cai, Fei; Jiang, Chuanhai

    2014-02-01

    Ni-Al composite coatings with different contents of Al microparticles were prepared from a conventional Watt bath. The influences of Al particle loadings in the bath on the surface morphology, composition, texture, grain size, microstrain, residual stress and anti-corrosion of the Ni-Al composite coating were investigated. The friction coefficients of the coatings at 200 °C were also evaluated by a pin-on-disctribometer. The results showed that the surface morphology of the coatings changed from pyramid + colonied structure to colonied structure with increasing Al particle loadings. The (2 0 0) preferred orientation for pure Ni coating evolved to random orientation with increasing Al particle loadings. The grain size obtained the minimum value of 72.28 nm at Al particle loading of 100 g/L and the microstrain of the coating increased with increasing the Al particle loadings. The incorporation of Al particles decreased the residual stress of the electro-deposited coating and all the coatings deposited at different Al particle loadings possessed low residual stress. As the Al particle loading increased, the anti-corrosion of the Ni-Al coatings increased owing to the combined effect of increasing Al content in the coatings and the texture evolution from (2 0 0) plane to (1 1 1) plane. The wear result suggested that the increasing Al particle content did not improve the wear performance of the Ni-Al composite coatings.

  6. ALS Association

    MedlinePlus

    ... toward a world without ALS! Walk to Defeat ALS® Walk to Defeat ALS® draws people of all ... We need your help. I Will Advocate National ALS Registry The National ALS Registry is a congressionally ...

  7. Effects of Childhood Stress Can Accumulate in the Body. Science Brief

    ERIC Educational Resources Information Center

    National Scientific Council on the Developing Child, 2008

    2008-01-01

    This brief presents the findings of a study that examined the effects of "allostatic load" on children in poverty at age 9 and 13. "Allostatic load" refers to the measurement of the cumulative wear and tear on the body that results from experiencing stress. Research shows that high allostatic load in childhood is associated with long-term…

  8. LOADING DEVICE

    DOEpatents

    Ohlinger, L.A.

    1958-10-01

    A device is presented for loading or charging bodies of fissionable material into a reactor. This device consists of a car, mounted on tracks, into which the fissionable materials may be placed at a remote area, transported to the reactor, and inserted without danger to the operating personnel. The car has mounted on it a heavily shielded magazine for holding a number of the radioactive bodies. The magazine is of a U-shaped configuration and is inclined to the horizontal plane, with a cap covering the elevated open end, and a remotely operated plunger at the lower, closed end. After the fissionable bodies are loaded in the magazine and transported to the reactor, the plunger inserts the body at the lower end of the magazine into the reactor, then is withdrawn, thereby allowing gravity to roll the remaining bodies into position for successive loading in a similar manner.

  9. Carbohydrate Loading.

    ERIC Educational Resources Information Center

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  10. ALS - resources

    MedlinePlus

    Resources - ALS ... The following organizations are good resources for information on amyotrophic lateral sclerosis : Muscular Dystrophy Association -- mda.org/disease/amyotrophic-lateral-sclerosis National Amyotrophic Lateral Sclerosis (ALS) Registry -- ...

  11. LOADED WAVEGUIDES

    DOEpatents

    Mullett, L.B.; Loach, B.G.; Adams, G.L.

    1958-06-24

    >Loaded waveguides are described for the propagation of electromagnetic waves with reduced phase velocities. A rectangular waveguide is dimensioned so as to cut-off the simple H/sub 01/ mode at the operating frequency. The waveguide is capacitance loaded, so as to reduce the phase velocity of the transmitted wave, by connecting an electrical conductor between directly opposite points in the major median plane on the narrower pair of waveguide walls. This conductor may take a corrugated shape or be an aperature member, the important factor being that the electrical length of the conductor is greater than one-half wavelength at the operating frequency. Prepared for the Second U.N. International ConferThe importance of nuclear standards is duscussed. A brief review of the international callaboration in this field is given. The proposal is made to let the International Organization for Standardization (ISO) coordinate the efforts from other groups. (W.D.M.)

  12. Al Composites

    NASA Astrophysics Data System (ADS)

    Chandanayaka, Tharaka; Azarmi, Fardad

    2014-05-01

    In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 μm were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

  13. Load sensing system

    DOEpatents

    Sohns, Carl W.; Nodine, Robert N.; Wallace, Steven Allen

    1999-01-01

    A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast

  14. Load forecasting by ANN

    SciTech Connect

    Highley, D.D.; Hilmes, T.J. )

    1993-07-01

    This article discusses the use and training of artificial neural networks (ANNs) for load forecasting. The topics of the article include a brief overview of neural networks, interest in ANNs, training of neural networks, a case study in load forecasting, and the potential for using an artificial neural network to perform short-term load forecasting.

  15. Discharge circuits and loads

    SciTech Connect

    Sarjeant, W.J.

    1980-10-15

    This will be an overview in which some of the general properties of loads are examined: their interface with the energy storage and switching devices; general problems encountered with different types of loads; how load behavior and fault modes can impact on the design of a power conditioning system (PCS).

  16. Load Model Data Tool

    2013-04-30

    The LMDT software automates the process of the load composite model data preparation in the format supported by the major power system software vendors (GE and Siemens). Proper representation of the load composite model in power system dynamic analysis is very important. Software tools for power system simulation like GE PSLF and Siemens PSSE already include algorithms for the load composite modeling. However, these tools require that the input information on composite load to bemore » provided in custom formats. Preparation of this data is time consuming and requires multiple manual operations. The LMDT software enables to automate this process. Software is designed to generate composite load model data. It uses the default load composition data, motor information, and bus information as an input. Software processes the input information and produces load composition model. Generated model can be stored in .dyd format supported by GE PSLF package or .dyr format supported by Siemens PSSE package.« less

  17. Load Model Data Tool

    SciTech Connect

    David Chassin, Pavel Etingov

    2013-04-30

    The LMDT software automates the process of the load composite model data preparation in the format supported by the major power system software vendors (GE and Siemens). Proper representation of the load composite model in power system dynamic analysis is very important. Software tools for power system simulation like GE PSLF and Siemens PSSE already include algorithms for the load composite modeling. However, these tools require that the input information on composite load to be provided in custom formats. Preparation of this data is time consuming and requires multiple manual operations. The LMDT software enables to automate this process. Software is designed to generate composite load model data. It uses the default load composition data, motor information, and bus information as an input. Software processes the input information and produces load composition model. Generated model can be stored in .dyd format supported by GE PSLF package or .dyr format supported by Siemens PSSE package.

  18. Shock Loading Studies of AP/AL/HTPB Based Propellants

    NASA Astrophysics Data System (ADS)

    Boteler, J. M.; Lindfors, A. J.

    1995-08-01

    The unreacted Hugoniots of three class 1.3 propellants have been investigated by shock compression experiments. Shock waves were generated by planar impact in a 75 mm single stage powder gun. Manganin and PVDF pressure gauges provided pressure-time histories to 200 kbar. The propellants were of similar formulation differing only in coarse AP particle size and the addition of a bum rate modifier (Fe2O3). All propellants contained 90% solids by weight and HTPB as binder. Results show negligible effect of AP particle size on shock response in contrast to the addition of Fe2O3 which appears to "stiffen" the host material. Within experimental error, the unreacted Hugoniots compare favorably to the solid AP Hugoniot. Five shock experiments were performed on propellant samples strained to induce in situ voids. The material state was quantified by uniaxial tension dilatometry. Experimental records suggest chemical reactivity behind the shock front. These results are discussed and compared to experimental studies reported previously.

  19. Shock Loading Studies of AP/AL/HTPB Based Propellants

    NASA Astrophysics Data System (ADS)

    Boteler, J. M.; Lindfors, A. J.

    1996-05-01

    The unreacted Hugoniots of three class 1.3 propellants have been investigated by shock compression experiments. Shock waves were generated by planar impact in a 75 mm single stage powder gun. Manganin and PVDF pressure gauges provided pressure-time histories to 200 kbar. The propellants were of similar formulation differing only in coarse AP particle size and the addition of a bum rate modifier ( Fe 2 O 3 ). All propellants contained 90% solids by weight and HTPB as binder. Results show negligible effect of AP particle size on shock response in contrast to the addition of Fe 2 O 3 which appears to "stiffen" the host material. Within experimental error, the unreacted Hugoniots compare favorably to the solid AP Hugoniot. Five shock experiments were performed on propellant samples strained to induce in situ voids. The material state was quantified by uniaxial tension dilatometry. Experimental records suggest chemical reactivity behind the shock front. These results are discussed and compared to experimental studies reported previously.

  20. Phalange Tactile Load Cell

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor); Griffith, Bryan Kristian (Inventor)

    2010-01-01

    A tactile load cell that has particular application for measuring the load on a phalange in a dexterous robot system. The load cell includes a flexible strain element having first and second end portions that can be used to mount the load cell to the phalange and a center portion that can be used to mount a suitable contact surface to the load cell. The strain element also includes a first S-shaped member including at least three sections connected to the first end portion and the center portion and a second S-shaped member including at least three sections coupled to the second end portion and the center portion. The load cell also includes eight strain gauge pairs where each strain gauge pair is mounted to opposing surfaces of one of the sections of the S-shaped members where the strain gauge pairs provide strain measurements in six-degrees of freedom.

  1. A comparative wear study on Al-Li and Al-Li/SiC composite

    SciTech Connect

    Okumus, S. Cem Karslioglu, Ramazan Akbulut, Hatem

    2013-12-16

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al{sub 2}O{sub 3} ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms{sup −1} and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  2. A comparative wear study on Al-Li and Al-Li/SiC composite

    NASA Astrophysics Data System (ADS)

    Okumus, S. Cem; Karslioglu, Ramazan; Akbulut, Hatem

    2013-12-01

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al2O3 ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms-1 and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  3. Load sensing system

    DOEpatents

    Sohns, C.W.; Nodine, R.N.; Wallace, S.A.

    1999-05-04

    A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast inventories of stored nuclear material can be continuously monitored and inventoried of minimal cost. 4 figs.

  4. Load regulating expansion fixture

    DOEpatents

    Wagner, L.M.; Strum, M.J.

    1998-12-15

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig.

  5. Load regulating expansion fixture

    DOEpatents

    Wagner, Lawrence M.; Strum, Michael J.

    1998-01-01

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components.

  6. Global Ice-loading History Reconstructed Over Five Glacial Cycles

    NASA Astrophysics Data System (ADS)

    Williams, F. H.; Grant, K. M.; Tamisiea, M. E.; Rohling, E. J.; Hibbert, F. D.

    2014-12-01

    High resolution ice-loading reconstructions are a vital tool not only for palaeoclimate studies, but also for providing a palaeoenvironmental context to human development. Here we present a global ice-loading history developed using the high resolution, Red Sea relative sea-level (RSL) record. (Siddall et al. 2003, Rohling et al. 2009, Grant et al. in submission) We use glacial isostatic adjustment modelling to determine a set of corrections to the Red Sea RSL record, which is then translated into a global mean sea level. This global mean sea level allows us to calculate a global ice volume. Global ice volume is geographically distributed within our ice-loading history according to currently available data regarding ice margins, their timing, and constraints on maximum ice load. Where constraints are sparse we use a combination of ICE-5G (Peltier, 2004) and the de Boer coupled ice sheet model (de Boer et al, 2014) as a template for ice distribution. Although an ice-loading history for the past 5 Myr exists, this is the first time that geographic constraints have been applied to global ice volumes over 5 glacial cycles. Our ice-loading reconstruction is further supported by the high resolution of our source RSL data. Our ice-loading history is tested against a global compilation of coral sea-level indicators (Hibbert et al., in prep.), and compared with ice histories developed from alternate ice volume reconstructions or RSL records, including a global ice history based on that developed by de Boer et al. (2014), the sea-level record of Waelbroeck et al. (2002) and a simple ice history based on the δ18O stack of Lisiecki and Raymo (2005).

  7. Microbial load monitor

    NASA Technical Reports Server (NTRS)

    Caplin, R. S.; Royer, E. R.

    1977-01-01

    Design analysis of a microbial load monitor system flight engineering model was presented. Checkout of the card taper and media pump system was fabricated as well as the final two incubating reading heads, the sample receiving and card loading device assembly, related sterility testing, and software. Progress in these areas was summarized.

  8. Combined Load Test Fixture

    NASA Technical Reports Server (NTRS)

    Baker, Donald J.

    2010-01-01

    A test fixture has been developed at NASA Langley Research Center that has the capability of applying compression load and shear load simultaneously to a test specimen. The test specimen size is 24-inches by 28-inches. This report describes the test specimen design, test specimen preparation, fixture assembly in the test machine, and a test operation plan.

  9. CRITICAL LOADS METHODS

    EPA Science Inventory

    I summarize the results of an interagency project that 1) defines a generic approach to quantifying and reporting critical loads, and 2) exercises that generic approach by examining a data rich system -- the critical loads of sulfur deposition and it's effect on the chronic acidi...

  10. Load Induced Blindness

    ERIC Educational Resources Information Center

    Macdonald, James S. P.; Lavie, Nilli

    2008-01-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005, for a review). Here we varied the level of…

  11. Transportation and handling loads

    NASA Technical Reports Server (NTRS)

    Ostrem, F. E.

    1971-01-01

    Criteria and recommended practices are presented for the prediction and verification of transportation and handling loads for the space vehicle structure and for monitoring these loads during transportation and handling of the vehicle or major vehicle segments. Elements of the transportation and handling systems, and the forcing functions and associated loads are described. The forcing functions for common carriers and typical handling devices are assessed, and emphasis is given to the assessment of loads at the points where the space vehicle is supported during transportation and handling. Factors which must be considered when predicting the loads include the transportation and handling medium; type of handling fixture; transport vehicle speed; types of terrain; weather (changes in pressure of temperature, wind, etc.); and dynamics of the transportation modes or handling devices (acceleration, deceleration, and rotations of the transporter or handling device).

  12. Cable load sensing device

    DOEpatents

    Beus, Michael J.; McCoy, William G.

    1998-01-01

    Apparatus for sensing the magnitude of a load on a cable as the cable is employed to support the load includes a beam structure clamped to the cable so that a length of the cable lies along the beam structure. A spacer associated with the beam structure forces a slight curvature in a portion of the length of cable under a cable "no-load" condition so that the portion of the length of cable is spaced from the beam structure to define a cable curved portion. A strain gauge circuit including strain gauges is secured to the beam structure by welding. As the cable is employed to support a load the load causes the cable curved portion to exert a force normal to the cable through the spacer and on the beam structure to deform the beam structure as the cable curved portion attempts to straighten under the load. As this deformation takes place, the resistance of the strain gauges is set to a value proportional to the magnitude of the normal strain on the beam structure during such deformation. The magnitude of the normal strain is manipulated in a control device to generate a value equal to the magnitude or weight of the load supported by the cable.

  13. Load Balancing Scientific Applications

    SciTech Connect

    Pearce, Olga Tkachyshyn

    2014-12-01

    The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

  14. Creep and Toughness of Cryomilled NiAl Containing Cr

    NASA Technical Reports Server (NTRS)

    Whittenberger, J. Daniel; Aikin, Beverly; Salem, Jon

    2000-01-01

    NiAl-AlN + Cr composites were produced by blending cryomilled NiAl powder with approx. 10 vol % Cr flakes. In comparison to the as-consolidated matrices, hot isostatically pressed Cr-modified materials did not demonstrate any significant improvement in toughness. Hot extruded NiAl-AlN+10.5Cr, however, possessed a toughness twice that determine for the base NiAl-AlN alloy. Measurement of the 1200 to 1400 K plastic flow properties revealed that the strength of the composites was completely controlled by the properties of the NiAl-AlN matrices. This behavior could be successfully modeled by the Rule-of-Mixtures, where load is shed from the weak Cr to the strong matrix.

  15. LOADING MACHINE FOR REACTORS

    DOEpatents

    Simon, S.L.

    1959-07-01

    An apparatus is described for loading or charging slugs of fissionable material into a nuclear reactor. The apparatus of the invention is a "muzzle loading" type comprising a delivery tube or muzzle designed to be brought into alignment with any one of a plurality of fuel channels. The delivery tube is located within the pressure shell and it is also disposed within shielding barriers while the fuel cantridges or slugs are forced through the delivery tube by an externally driven flexible ram.

  16. Load research manual. Volume 3. Load research for advanced technologies

    SciTech Connect

    Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

    1980-11-01

    This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. The manual includes guides to load research literature and glossaries of load research and statistical terms. In Volume 3, special load research procedures are presented for solar, wind, and cogeneration technologies.

  17. Creep in Directionally Solidified NiAl-Mo Eutectics

    SciTech Connect

    Dudova, Marie; Kucharova, Kveta; Bartak, Tomas; Bei, Hongbin; George, Easo P; Somsen, Ch.; Dlouhy, A.

    2011-01-01

    A directionally solidified NiAl-Mo eutectic and an NiAl intermetallic, having respective nominal compositions Ni-45.5Al-9Mo and Ni-45.2Al (at.%), were loaded in compression at 1073 and 1173 K. Formidable strengthening by regularly distributed Mo fibres (average diameter 600 nm, volume fraction 14%) was observed. The fibres can support compression stresses transferred from the plastically deforming matrix up to a critical stress of the order of 2.5 GPa, at which point they yield. Microstructural evidence is provided for the dislocation-mediated stress transfer from the NiAl to the Mo phase.

  18. A load factor formula

    NASA Technical Reports Server (NTRS)

    Miller, Roy G

    1927-01-01

    The ultimate test of a load factor formula is experience. The chief advantages of a semi rational formula over arbitrary factors are that it fairs in between points of experience and it differentiates according to variables within a type. Structural failure of an airplane apparently safe according to the formula would call for a specific change in the formula. The best class of airplanes with which to check a load factor formula seems to be those which have experienced structural failure. Table I comprises a list of the airplanes which have experienced failure in flight traceable to the wing structure. The load factor by formula is observed to be greater than the designed strength in each case, without a single exception. Table II comprises the load factor by formula with the designed strength of a number of well-known service types. The formula indicates that by far the majority of these have ample structural strength. One case considered here in deriving a suitable formula is that of a heavy load carrier of large size and practically no reserve power.

  19. E-2C Loads Calibration in DFRC Flight Loads Lab

    NASA Technical Reports Server (NTRS)

    Schuster, Lawrence S.

    2008-01-01

    Objectives: a) Safely and efficiently perform structural load tests on NAVAIR E-2C aircraft to calibrate strain gage instrumentation installed by NAVAIR; b) Collect load test data and derive loads equations for use in NAVAIR flight tests; and c) Assist flight test team with use of loads equations measurements at PAX River.

  20. Shuttle car loading system

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr. (Inventor)

    1985-01-01

    A system is described for loading newly mined material such as coal, into a shuttle car, at a location near the mine face where there is only a limited height available for a loading system. The system includes a storage bin having several telescoping bin sections and a shuttle car having a bottom wall that can move under the bin. With the bin in an extended position and filled with coal the bin sections can be telescoped to allow the coal to drop out of the bin sections and into the shuttle car, to quickly load the car. The bin sections can then be extended, so they can be slowly filled with more while waiting another shuttle car.

  1. Microbial load monitor

    NASA Technical Reports Server (NTRS)

    Caplin, R. S.; Royer, E. R.

    1978-01-01

    Attempts are made to provide a total design of a Microbial Load Monitor (MLM) system flight engineering model. Activities include assembly and testing of Sample Receiving and Card Loading Devices (SRCLDs), operator related software, and testing of biological samples in the MLM. Progress was made in assembling SRCLDs with minimal leaks and which operate reliably in the Sample Loading System. Seven operator commands are used to control various aspects of the MLM such as calibrating and reading the incubating reading head, setting the clock and reading time, and status of Card. Testing of the instrument, both in hardware and biologically, was performed. Hardware testing concentrated on SRCLDs. Biological testing covered 66 clinical and seeded samples. Tentative thresholds were set and media performance listed.

  2. Estimating turbine limit load

    NASA Technical Reports Server (NTRS)

    Glassman, Arthur J.

    1993-01-01

    A method for estimating turbine limit-load pressure ratio from turbine map information is presented and demonstrated. It is based on a mean line analysis at the last-rotor exit. The required map information includes choke flow rate at all speeds as well as pressure ratio and efficiency at the onset of choke at design speed. One- and two-stage turbines are analyzed to compare the results with those from a more rigorous off-design flow analysis and to show the sensitivities of the computed limit-load pressure ratios to changes in the key assumptions.

  3. Ocean Tide Loading Computation

    NASA Technical Reports Server (NTRS)

    Agnew, Duncan Carr

    2005-01-01

    September 15,2003 through May 15,2005 This grant funds the maintenance, updating, and distribution of programs for computing ocean tide loading, to enable the corrections for such loading to be more widely applied in space- geodetic and gravity measurements. These programs, developed under funding from the CDP and DOSE programs, incorporate the most recent global tidal models developed from Topex/Poscidon data, and also local tide models for regions around North America; the design of the algorithm and software makes it straightforward to combine local and global models.

  4. LOADING AND UNLOADING DEVICE

    DOEpatents

    Treshow, M.

    1960-08-16

    A device for loading and unloading fuel rods into and from a reactor tank through an access hole includes parallel links carrying a gripper. These links enable the gripper to go through the access hole and then to be moved laterally from the axis of the access hole to the various locations of the fuel rods in the reactor tank.

  5. Multidimensional spectral load balancing

    DOEpatents

    Hendrickson, Bruce A.; Leland, Robert W.

    1996-12-24

    A method of and apparatus for graph partitioning involving the use of a plurality of eigenvectors of the Laplacian matrix of the graph of the problem for which load balancing is desired. The invention is particularly useful for optimizing parallel computer processing of a problem and for minimizing total pathway lengths of integrated circuits in the design stage.

  6. Al-matrix composite materials reinforced by Al-Cu-Fe particles

    NASA Astrophysics Data System (ADS)

    Bonneville, J.; Laplanche, G.; Joulain, A.; Gauthier-Brunet, V.; Dubois, S.

    2010-07-01

    Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal ω-Al00.70Cu0.20Fe0.10 crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/ω, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particul ar in yield stress values. In the low temperatureregime (T <= 570K), the yield stress of the Al/ω composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

  7. Measuring alignment of loading fixture

    DOEpatents

    Scavone, Donald W.

    1989-01-01

    An apparatus and method for measuring the alignment of a clevis and pin type loading fixture for compact tension specimens include a pair of substantially identical flat loading ligaments. Each loading ligament has two apertures for the reception of a respective pin of the loading fixture and a thickness less than one-half of a width of the clevis opening. The pair of loading ligaments are mounted in the clevis openings at respective sides thereof. The loading ligaments are then loaded by the pins of the loading fixture and the strain in each loading ligament is measured. By comparing the relative strain of each loading ligament, the alignment of the loading fixture is determined. Preferably, a suitable strain gage device is located at each longitudinal edge of a respective loading ligament equidistant from the two apertures in order to determine the strain thereat and hence the strain of each ligament. The loading ligaments are made substantially identical by jig grinding the loading ligaments as a matched set. Each loading ligament can also be individually calibrated prior to the measurement.

  8. Estimating a percent reduction in load

    NASA Astrophysics Data System (ADS)

    Millard, Steven P.

    This article extends the work of Cohn et al. [1989] on estimating constituent loads to the problem of estimating a percent reduction in load. Three estimators are considered: the maximum likelihood (MLE), a ``bias-corrected'' maximum likelihood (BCMLE), and the minimum variance unbiased (MVUE). In terms of root-mean-square error, both the MVUE and BCMLE are superior to the MLE, and for the cases considered here there is no appreciable difference between the MVUE and the BCMLE. The BCMLE is constructed from quantities computed by most regression packages and is therefore simpler to compute than the MVUE (which involves approximating an infinite series). All three estimators are applied to a case study in which an agricultural tax in the Everglades agricultural area is tied to an observed percent reduction in phosphorus load. For typical hydrological data, very large sample sizes (of the order of 100 observations each in the baseline period and after) are required to estimate a percent reduction in load with reasonable precision.

  9. Soil solution sensitivity to low pollution load

    NASA Astrophysics Data System (ADS)

    Gorbacheva, Tamara; Kikuchi, Ryunosuke

    2014-05-01

    Murmansk region (Russian Federation) is included in environmental hot spots list (2003 report of NEFCO and AMAP). Annual emissions of SO2 from stationary sources (largest is Kola Mining and Metallurgical Company) and autotransport decreased in XXI century and sustained (tons) as: 282942 (2000); 2002 - 249400 (2002); 240110 (2003); 225573 (2005); 217872 (2006); 215910 (2007); 206910 (2008); 211210 (2009); 21554 (2010); 199500 (2011); 194600 (2012). Kola Peninsula terrestrial ecosystems tolerance to atmospheric S deposition was assessed on the basis of the critical load concept: most sensitive ecosystems (critical sulfur load less 400 equiv per ha per year) occupy 58% of the total area; zones at risk of excess sulfur input into ecosystems cover more than 20% of the Kola Peninsula (Koptsik et al., 2008). We attempted to estimate soil solution sensitivity to long-term, but low pollution load by sulfur dioxide in southwest direction from Monchegorsk smelter: (1) - 260 km away, 66o50,45'N; 30o 12,34'E) and (2) - 100 km away, 67o22,837'N; 32o26,016'E). The investigations were carried out during 2003-2008 period on permanent monitoring plots of INEP equipped by deposition collectors and zero-tension lyzimeters. Monitoring plots are located in similar native conditions: Site altitude - 170 m (2) vrs. 132 m (1); Forest type - Piceetum empetroso-myrtillosum-hylocomiosa; Stand history- no thining, no fires; Silvicultural history - no. Soil properties are similar too: Soil type (FAO) - ferric podzol (both plots); organic layer thickness 0-16cm (2) vrs. 0-11cm (1), E horizon thickness 16-27cm (2) vrs. 11-22cm (1), B horizon 27-51cm (2) vrs. 22-47 cm (1); parent material - glacial till (both plots). Plots are differed by annual sulfate pollution load (estimated as snow plus rain): 0.09-0.26 gm-2 (1) vrs. 0.14-0.43 gm-2(2), but both plots are refered to background plots. So, background modelled data of S deposition in the Border Areas of Norway and Russia is 0.1 - 0.2 gm-2

  10. Development of the Estimation Service of the Earth's Surface Fluid Load Effects for Space Geodetic Techniques

    NASA Astrophysics Data System (ADS)

    Takiguchi, H.; Gotoh, T.; Otsubo, T.

    2010-12-01

    Temporal changes of surface loadings due to the mass redistribution of the fluid envelope of the Earth, i.e., the atmosphere, hydrosphere, and cryosphere, cause the Earth to deform and consequently change the coordinates of observation sites. The coordinate changes can be measured by space geodetic techniques such as VLBI and GPS. From the viewpoint of crustal movements, such displacements due to these noises should be eliminated. In 2006, for the reduction of these influences, we estimated the crustal displacements due to atmospheric loading (AL), non-tidal ocean loading (NTOL), continental water loading (CWL) and snow loading (SL) influences. And we showed that a combination of AL, NTOL, and CWL can eliminate about 20% of the annual signal in the GPS coordinate time series (Takiguchi et al., 2006). We also applied the correction to the data of 1997 Bungo channel slow slip event and confirmed that the loading correction can be well applied for the analysis of the slow slip event. In this study, we are developing the calculation service about the displacement of the Earth's surface loads for space geodetic techniques. Previous study, we showed the influences of several loads and the necessity to correct loads for precise geodetic analysis. However it is not easy to calculate the influences of loads. So, we are planning to develop the displacement database based on the web. This database runs as a service to calculate the load displacements at arbitrary time and arbitrary location by arbitrary users. This service can calculate the several loads such as AL, NTOL and CWL. We are also planning to provide the load corrected site coordinates about world wide GPS sites analyzed by the ‘concerto’ program version 4 for GPS developed by NICT. In the presentation, we will introduce the calculation service and the result of load correction analysis. This work was supported by JSPS KAKENHI (Grant-in-Aid for Young Scientists (B) 21740333).

  11. Wind loading on solar collectors

    SciTech Connect

    Bhaduri, S.; Murphy, L.M.

    1985-06-01

    The present design methodology for the determination of wind loading on the various solar collectors has been reviewed and assessed. The total force coefficients of flat plates of aspect ratios 1.0 and 3.0, respectively, at various angles of attack obtained by using the guidelines of the ANSI A58.1-1982, have been compared with those obtained by using the methodology of the ASCE Task Committee, 1961, and the experimental results of the full-scale test of heliostats by Peglow. The turbulent energy spectra, currently employed in the building code, are compared with those of Kaimal et al., Lumley, and Ponofsky for wind velocities of 20.0 m/s and 40.24 m/s at an elevation of 9.15 m. The longitudinal spectra of the building code overestimates the Kaimal spectra in the frequency range of 0.007 Hz to 0.08 Hz and underestimates beyond the frequency of 0.08 Hz. The peak angles of attack, on the heliostat, stowed in horizontal position, due to turbulent vertical and lateral components of wind velocity, have been estimated by using Daniel's methodology for three wind velocities and compared with the value suggested by the code. The experimental results of a simple test in the laboratory indicate the feasibility of decreasing the drag forces of the flat plate by reducing the solidity ratio.

  12. Load measurement system with load cell lock-out mechanism

    NASA Astrophysics Data System (ADS)

    Le, Thang; Carroll, Monty; Liu, Jonathan

    1995-05-01

    In the frame work of the project Shuttle Plume Impingement Flight Experiment (SPIFEX), a Load Measurement System was developed and fabricated to measure the impingement force of Shuttle Reaction Control System (RCS) jets. The Load Measurement System is a force sensing system that measures any combination of normal and shear forces up to 40 N (9 lbf) in the normal direction and 22 N (5 lbf) in the shear direction with an accuracy of +/- 0.04 N (+/- 0.01 lbf) Since high resolution is required for the force measurement, the Load Measurement System is built with highly sensitive load cells. To protect these fragile load cells in the non-operational mode from being damaged due to flight loads such as launch and landing loads of the Shuttle vehicle, a motor driven device known as the Load Cell Lock-Out Mechanism was built. This Lock-Out Mechanism isolates the load cells from flight loads and re-engages the load cells for the force measurement experiment once in space. With this highly effective protection system, the SPIFEX load measurement experiment was successfully conducted on STS-44 in September 1994 with all load cells operating properly and reading impingement forces as expected.

  13. Plutonium Immobilization Canister Loading

    SciTech Connect

    Hamilton, E.L.

    1999-01-26

    This disposition of excess plutonium is determined by the Surplus Plutonium Disposition Environmental Impact Statement (SPD-EIS) being prepared by the Department of Energy. The disposition method (Known as ''can in canister'') combines cans of immobilized plutonium-ceramic disks (pucks) with vitrified high-level waste produced at the SRS Defense Waste Processing Facility (DWPF). This is intended to deter proliferation by making the plutonium unattractive for recovery or theft. The envisioned process remotely installs cans containing plutonium-ceramic pucks into storage magazines. Magazines are then remotely loaded into the DWPF canister through the canister neck with a robotic arm and locked into a storage rack inside the canister, which holds seven magazines. Finally, the canister is processed through DWPF and filled with high-level waste glass, thereby surrounding the product cans. This paper covers magazine and rack development and canister loading concepts.

  14. Shot loading trainer analysis

    SciTech Connect

    Peterson, T.K.

    1995-02-15

    This document presents the results from the analysis of the shot loading trainer (SLT). This device will be used to test the procedure for installing shot into the annulus of the Project W-320 shipping container. To ensure that the shot is installed uniformly around the container, vibrators will be used to settle the shot. The SLT was analyzed to ensure that it would not jeopardize worker safety during operation. The results from the static analysis of the SLT under deadweight and vibrator operating loads show that the stresses in the SLT are below code allowables. The results from the modal analysis show that the natural frequencies of the SLT are far below the operating frequencies of the vibrators, provided the SLT is mounted on pneumatic tires. The SLT was also analyzed for wind, seismic, deadweight, and moving/transporting loads. Analysis of the SLT is in accordance with SDC-4.1 for safety class 3 structures (DOE-RL 1993) and the American Institute of Steel Construction (AISC) Manual of Steel Construction (AISC 1989).

  15. Load responsive hydrodynamic bearing

    DOEpatents

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  16. Load regulating latch

    NASA Technical Reports Server (NTRS)

    Appleberry, W. T. (Inventor)

    1977-01-01

    A load regulating mechanical latch is described that has a pivotally mounted latch element having a hook-shaped end with a strike roller-engaging laterally open hook for engaging a stationary strike roller. The latch element or hook is pivotally mounted in a clevis end of an elongated latch stem that is adapted for axial movement through an opening in a support plate or bracket mounted to a structural member. A coil spring is disposed over and around the extending latch stem and the lower end of the coil spring engages the support bracket. A thrust washer is removably attached to the other end of the latch stem and engages the other end of the coil spring and compresses the coil spring thereby preloading the spring and the latch element carried by the latch stem. The hook-shaped latch element has a limited degree of axial travel for loading caused by structural distortion which may change the relative positions of the latch element hook and the strike roller. Means are also provided to permit limited tilt of the latch element due to loading of the hook.

  17. Buffet Load Alleviation

    NASA Technical Reports Server (NTRS)

    Ryall, T. G.; Moses, R. W.; Hopkins, M. A.; Henderson, D.; Zimcik, D. G.; Nitzsche, F.

    2004-01-01

    High performance aircraft are, by their very nature, often required to undergo maneuvers involving high angles of attack. Under these conditions unsteady vortices emanating from the wing and the fuselage will impinge on the twin fins (required for directional stability) causing excessive buffet loads, in some circumstances, to be applied to the aircraft. These loads result in oscillatory stresses, which may cause significant amounts of fatigue damage. Active control is a possible solution to this important problem. A full-scale test was carried out on an F/A-18 fuselage and fins using piezoceramic actuators to control the vibrations. Buffet loads were simulated using very powerful electromagnetic shakers. The first phase of this test was concerned with the open loop system identification whereas the second stage involved implementing linear time invariant control laws. This paper looks at some of the problems encountered as well as the corresponding solutions and some results. It is expected that flight trials of a similar control system to alleviate buffet will occur as early as 2001.

  18. Electrical Load Modeling and Simulation

    SciTech Connect

    Chassin, David P.

    2013-01-01

    Electricity consumer demand response and load control are playing an increasingly important role in the development of a smart grid. Smart grid load management technologies such as Grid FriendlyTM controls and real-time pricing are making their way into the conventional model of grid planning and operations. However, the behavior of load both affects, and is affected by load control strategies that are designed to support electric grid planning and operations. This chapter discussed the natural behavior of electric loads, how it interacts with various load control and demand response strategies, what the consequences are for new grid operation concepts and the computing issues these new technologies raise.

  19. 32. VAL, DETAIL SHOWING LOADING PLATFORM, PROJECTILE LOADING CAR, LAUNCHER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. VAL, DETAIL SHOWING LOADING PLATFORM, PROJECTILE LOADING CAR, LAUNCHER SLAB AND UNDERSIDE OF LAUNCHER BRIDGE LOOKING SOUTHWEST. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  20. COKE STORAGE HOPPER LOCATED OUTSIDE THE MALLEABLE FOUNDRY SHOWING LOADING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    COKE STORAGE HOPPER LOCATED OUTSIDE THE MALLEABLE FOUNDRY SHOWING LOADING DEVICE THAT USED A SKIP CAR TO FILL THE HOPPER FROM UNDERGROUND GRAVITY-FED STORAGE AREAS FROM INCOMING RAILROAD CARS. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  1. Fabrication and properties of functionally graded NiAl/Al2O3 composites

    NASA Technical Reports Server (NTRS)

    Miller, D. P.; Lannutti, J. J.; Noebe, R. D.

    1993-01-01

    A modified sedimentation process was used in the production of a functionally gradient material (FGM), NiAl/Al2O3. A simple finite element model was used to guide our design and fabrication efforts by estimating residual stress states as a function of composite structure. This approach could lead to tailored designs that enhance or avoid specific residual stress states. Thermal cycling tests were factored into the model to predict time dependent or steady-state internal temperature and stress profiles. Four-point bend tests were conducted to establish the mechanical load-displacement behavior of a single interlayer FGM at room temperature, 800 and 1000 K. Room temperature bend strength of the FGM was 3-4 times that of the base NiAl. At elevated temperatures, composite fracture occurred in a gradual, noncatastrophic mode involving NiAl retardation of a succession of cracks originating in the alumina face.

  2. Mesoscale studies of mixing in reactive materials during shock loading

    NASA Astrophysics Data System (ADS)

    Lomov, Ilya; Herbold, Eric B.; Austin, Ryan A.

    2012-03-01

    One of the requisite processes for chemical reactions between solid powder particles resulting from shock loading is that the particles undergo large deformations, exposing new surfaces while mixing with surrounding material. Reactions under shock loading occur in a reaction zone, the extent of which is defined by the interfacial surface area and the depth of the diffusion layer. The former depends on the level of hydrodynamic mixing of heterogeneous material under shock, while the latter depends on temperaturedependent species diffusion. To investigate diffusion-limited reactions at the grain scale level, mass diffusion and simple reaction kinetics depending on the interfacial surface area have been implemented in an Eulerian hydrocode GEODYN. Diffusion-reaction processes that are initiated by rapid heating of a Ni/Al nanolaminate and by shock loading of a micron-scale Ni/Al powder mixture are considered.

  3. Attack robustness of cascading load model in interdependent networks

    NASA Astrophysics Data System (ADS)

    Wang, Jianwei; Wu, Yuedan; Li, Yun

    2015-08-01

    Considering the weight of a node and the coupled strength of two interdependent nodes in the different networks, we propose a method to assign the initial load of a node and construct a new cascading load model in the interdependent networks. Assuming that a node in one network will fail if its degree is 0 or its dependent node in the other network is removed from the network or the load on it exceeds its capacity, we study the influences of the assortative link (AL) and the disassortative link (DL) patterns between two networks on the robustness of the interdependent networks against cascading failures. For better evaluating the network robustness, from the local perspective of a node we present a new measure to qualify the network resiliency after targeted attacks. We show that the AL patterns between two networks can improve the robust level of the entire interdependent networks. Moreover, we obtain how to efficiently allocate the initial load and select some nodes to be protected so as to maximize the network robustness against cascading failures. In addition, we find that some nodes with the lower load are more likely to trigger the cascading propagation when the distribution of the load is more even, and also give the reasonable explanation. Our findings can help to design the robust interdependent networks and give the reasonable suggestion to optimize the allocation of the protection resources.

  4. Plug Loads Conservation Measures

    2010-12-31

    This software requires inputs of simple plug loads inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: Vending Machine Misers, Delamp Vending Machine, Desktop to Laptop retrofit, CRT to LCD monitors retrofit, Computer Power Management Settings, and Energy Star Refrigerator retrofit. This tool calculates energy savings, demand reduction, cost savings, building life cycle costs including: simple payback, discounted payback, net-present value, and savings tomore » investment ratio. In addition this tool also displays the environmental benefits of a project.« less

  5. Microbial Load Monitor

    NASA Technical Reports Server (NTRS)

    Gibson, S. F.; Royer, E. R.

    1979-01-01

    The Microbial Load Monitor (MLM) is an automated and computerized system for detection and identification of microorganisms. Additionally, the system is designed to enumerate and provide antimicrobic susceptibility profiles for medically significant bacteria. The system is designed to accomplish these tasks in a time of 13 hours or less versus the traditional time of 24 hours for negatives and 72 hours or more for positives usually required for standard microbiological analysis. The MLM concept differs from other methods of microbial detection in that the system is designed to accept raw untreated clinical samples and to selectively identify each group or species that may be present in a polymicrobic sample.

  6. Variable loading roller

    DOEpatents

    Williams, D.M.

    1988-01-21

    An automatic loading roller for transmitting torque in traction drive devices in manipulator arm joints includes a two-part camming device having a first cam portion rotatable in place on a shaft by an input torque and a second cam portion coaxially rotatable and translatable having a rotating drive surface thereon for engaging the driven surface of an output roller with a resultant force proportional to the torque transmitted. Complementary helical grooves in the respective cam portions interconnected through ball bearings interacting with those grooves effect the rotation and translation of the second cam portion in response to rotation of the first. 14 figs.

  7. Variable loading roller

    DOEpatents

    Williams, Daniel M.

    1989-01-01

    An automatic loading roller for transmitting torque in traction drive devices in manipulator arm joints includes a two-part camming device having a first cam portion rotatable in place on a shaft by an input torque and a second cam portion coaxially rotatable and translatable having a rotating drive surface thereon for engaging the driven surface of an output roller with a resultant force proportional to the torque transmitted. Complementary helical grooves on the respective cam portions interconnected through ball bearings interacting with those grooves effect the rotation and translation of the second cam portion in response to rotation of the first.

  8. Multidimensional spectral load balancing

    SciTech Connect

    Hendrickson, B.; Leland, R.

    1993-01-01

    We describe an algorithm for the static load balancing of scientific computations that generalizes and improves upon spectral bisection. Through a novel use of multiple eigenvectors, our new spectral algorithm can divide a computation into 4 or 8 pieces at once. These multidimensional spectral partitioning algorithms generate balanced partitions that have lower communication overhead and are less expensive to compute than those produced by spectral bisection. In addition, they automatically work to minimize message contention on a hypercube or mesh architecture. These spectral partitions are further improved by a multidimensional generalization of the Kernighan-Lin graph partitioning algorithm. Results on several computational grids are given and compared with other popular methods.

  9. Plug Loads Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    2010-12-31

    This software requires inputs of simple plug loads inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: Vending Machine Misers, Delamp Vending Machine, Desktop to Laptop retrofit, CRT to LCD monitors retrofit, Computer Power Management Settings, and Energy Star Refrigerator retrofit. This tool calculates energy savings, demand reduction, cost savings, building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  10. Improved load ratio method for predicting crack length

    SciTech Connect

    Chen, X.; Albrecht, P.; Wright, W.; Joyce, J.A.

    1995-04-01

    The elastic compliance from unloading/reloading sequences in a load-displacement record estimates well crack length in elastic-plastic fracture toughness tests of compact tension [C(T)] and bending type specimens. The need for partial unloading of the specimen makes it difficult to run the test under static loading and impossible under either dynamic loading or very high temperatures. Furthermore, fracture toughness testing in which crack length is determined from elastic compliance requires high precision testing equipment and highly skilled technicians. As a result, such tests are confined usually to research laboratories and seldom used under production settings. To eliminate these problems, an improved load ratio method of predicting crack length is proposed that utilizes only the recorded load versus load-line displacement curve (or load versus crack-mouth-opening displacement curve) without unloading/reloading sequences. As a result, the instrumentation is much simpler than in the elastic compliance or potential drop methods. If only a monotonic load-displacement record is to be measured the fracture toughness test becomes almost as simple to perform as a tension test. The method described here improves in three ways the ``original load ratio method`` proposed by Hu et al. First, a blunting term is added to the crack length before maximum load. Second, a strain hardening correction is included after maximum load. And, third, the initial crack length and the physical (final) crack length measured at the end of the test serve to anchor the predicted crack lengths, forcing agreement between predicted and measured values. The method predicts crack extension with excellent accuracy in specimens fabricated from A302, A508, and A533B piping and pressure vessel steels, A588 and A572 structural steels, and HY-80 ship steel.

  11. Effects of proof loads and combined mode loadings on fracture and flaw growth characteristics of aerospace alloys

    NASA Technical Reports Server (NTRS)

    Shah, R. C.

    1974-01-01

    This experimental program was undertaken to determine the effects of (1) combined tensile and bending loadings, (2) combined tensile and shear loadings, and (3) proof overloads on fracture and flaw growth characteristics of aerospace alloys. Tests were performed on four alloys: 2219-T87 aluminum, 5Al-2.5Sn (ELl) titanium, 6Al-4V beta STA titanium and high strength 4340 steel. Tests were conducted in room air, gaseous nitrogen at -200F (144K), liquid nitrogen and liquid hydrogen. Flat center cracked and surface flawed specimens, cracked tube specimens, circumferentially notched round bar and surface flawed cylindrical specimens were tested. The three-dimensional photoelastic technique of stress freezing and slicing was used to determine stress intensity factors for surface flawed cylindrical specimens subjected to tension or torsion. Results showed that proof load/temperature histories used in the tests have a small beneficial effect or no effect on subsequent fracture strength and flaw growth rates.

  12. Load Control System Reliability

    SciTech Connect

    Trudnowski, Daniel

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  13. Hanford Apatite Treatability Test Report Errata: Apatite Mass Loading Calculation

    SciTech Connect

    Szecsody, James E.; Vermeul, Vincent R.; Williams, Mark D.; Truex, Michael J.

    2014-05-19

    The objective of this errata report is to document an error in the apatite loading (i.e., treatment capacity) estimate reported in previous apatite treatability test reports and provide additional calculation details for estimating apatite loading and barrier longevity. The apatite treatability test final report (PNNL-19572; Vermeul et al. 2010) documents the results of the first field-scale evaluation of the injectable apatite PRB technology. The apatite loading value in units of milligram-apatite per gram-sediment is incorrect in this and some other previous reports. The apatite loading in units of milligram phosphate per gram-sediment, however, is correct, and this is the unit used for comparison to field core sample measurements.

  14. Efficient thermoelectric cooling of concentrated heat loads

    NASA Astrophysics Data System (ADS)

    Hershberger, Jeff; Smythe, Robert; Gu, Xiaoyi; Hill, Richard F.

    2013-02-01

    An efficiency improvement of 87% is demonstrated in cooling of concentrated heat loads when using thermoelectric coolers (TECs) constructed with thermally conductive printed circuit boards (TCPCBs) as compared to traditional ceramic-based TECs. Laser diodes and infrared detectors must be actively cooled but are smaller than typical TECs. As a result, heat spreading must occur between the optical component and the semiconductor pellets near the edge of the TEC. Typically, TECs based on aluminum nitride circuit boards are chosen and in some cases an AlN plate is added between the optical component and the TEC. To address this, TECs have been developed that replace the ceramic circuit boards with laminated TCPCBs containing a thick copper backing. The copper backing improves heat spreading within the TEC. A study was conducted to quantify differences in coefficient of performance (COP, heat pumped divided by electrical power consumed) when cooling concentrated heat loads. A heat source 3 mm wide was cooled by TECs ~12 mm wide, comparing ceramic-based and TCPCB-based TECs of otherwise identical design. With a fixed hot side temperature and heat load, each TEC was powered to achieve a desired temperature at the heat source. Ceramic-based and TCPCB-based TECs exhibited COPs of 0.235 and 0.440 respectively, an 87% improvement. Further improvements are achievable: adding a thick copper plate between the heat source and the TEC resulted in a COP of ~0.59 for both TEC types.

  15. [Environmental factors in ALS].

    PubMed

    Juntas-Morales, Raul; Pageot, Nicolas; Corcia, Philippe; Camu, William

    2014-05-01

    ALS is likely to be a disorder of multifactorial origin. Among all the factors that may increase the risk of ALS, environmental ones are being studied for many years, but in the recent years, several advances have pointed to a new interest in their potential involvement in the disease process, especially for the cyanotoxin BMAA. Food containing BMAA has been found on Guam, a well-known focus of ALS/parkinsonism/dementia and high levels of BMAA have been identified into the brain of these patients. The BMAA cyanotoxin is potentially ubiquitous and have also been found into the food of patients who died from ALS both in Europe and USA. BMAA can be wrongly integrated into the protein structure during mRNA traduction, competing with serine. This may induce abnormal protein folding and a subsequent cell death. Heavy metals, such as lead or mercury may be directly toxic for neuronal cells. Several works have suggested an increased risk of ALS in individuals chronically exposed to these metals. Exposure to pesticides has been suggested to be linked to an increased risk of developing ALS. The mechanism of their toxicity is likely to be mediated by paraoxonases. These proteins are in charge of detoxifying the organism from toxins, and particularly organophosphates. To date, there are insufficient scientific data to suggest that exposure to electromagnetic fields may increase the risk of having ALS. We are particularly missing longitudinal cohorts to demonstrate that risk.

  16. Cable load transducer

    NASA Astrophysics Data System (ADS)

    Hassan, Scott E.; Abdow, David A.

    1994-10-01

    An apparatus for measuring the loads, moments and torque at a constrained end of a cable created by the action of the cable in a fluid medium in which the cable is suspended. The cable is suspended in the medium by means of a strut. The apparatus connects the cable to the strut. The apparatus includes two flexure members, one rigidly connected to the strut, the other to the cable. A universal joint couples the two flexure members so that the flexure member connected to the strut can be fitted with strain gages to measure bending while the other flexure member has strain gages to measure axial force and torque. The universal joint enables the isolation of axial and torsional strains at the flexure member connected to the cable.

  17. Offshore tanker loading system

    SciTech Connect

    Baan, J. de; Heijst, W.J. van.

    1994-01-04

    The present invention relates to an improved flexible loading system which provides fluid communication between a subsea pipeline and a surface vessel including a hose extending from the subsea pipeline to a first buoyancy tank, a second hose extending from the first buoyancy tank to a central buoyancy tank, a second buoyancy tank, means connecting said second buoyancy tank to the sea floor and to the central buoyancy tank whereby the forces exerted on said central buoyant tank by said second hose and said connecting means are balanced to cause said central buoyancy tank to maintain a preselected position, a riser section extending upwardly from said central buoyancy tank and means on the upper termination for engagement by a vessel on the surface to raise said upper termination onto the vessel to complete the communication for moving fluids between the subsea pipeline and the vessel. In one form the means for connecting between the sea floor to the second buoyancy tank includes an anchor on the sea floor and lines extending from the anchor to the second buoyancy tank and from the second buoyancy tank to the central buoyancy tank. In another form of the invention the means for connecting is a third hose extending from a second subsea pipeline to the second buoyancy tank and a fourth hose extending from the second buoyancy tank to the central buoyancy tank. The central buoyancy tank is preferred to be maintained at a level below the water surface which allows full movement of the vessel while connected to the riser section. A swivel may be positioned in the riser section and a pressure relief system may be included in the loading system to protect it from sudden excess pressures. 17 figs.

  18. Amyotrophic Lateral Sclerosis (ALS)

    MedlinePlus

    ... Pictures of ALS Mutant Proteins Support Two Major Theories About How the Disease is Caused May 2003 ... All NINDS-prepared information is in the public domain and may be freely copied. Credit to the ...

  19. Genetic Testing for ALS

    MedlinePlus

    ... Involved Donate Familial Amyotrophic Lateral Sclerosis (FALS) and Genetic Testing By Deborah Hartzfeld, MS, CGC, Certified Genetic ... guarantee a person will develop symptoms of ALS. Genetic Counseling If there is more than one person ...

  20. All About ALS

    MedlinePlus

    ... External link, please review our exit disclaimer . Subscribe All About ALS Understanding a Devastating Disorder In the ... a coffee pot, or button a shirt. Eventually, all muscles under voluntary control are affected, and people ...

  1. What Is ALS?

    MedlinePlus

    ... scarring or hardening ("sclerosis") in the region. Motor neurons reach from the brain to the spinal cord ... the body. The progressive degeneration of the motor neurons in ALS eventually leads to their demise. When ...

  2. Extensive genetics of ALS

    PubMed Central

    Calvo, Andrea; Mazzini, Letizia; Cantello, Roberto; Mora, Gabriele; Moglia, Cristina; Corrado, Lucia; D'Alfonso, Sandra; Majounie, Elisa; Renton, Alan; Pisano, Fabrizio; Ossola, Irene; Brunetti, Maura; Traynor, Bryan J.; Restagno, Gabriella

    2012-01-01

    Objective: To assess the frequency and clinical characteristics of patients with mutations of major amyotrophic lateral sclerosis (ALS) genes in a prospectively ascertained, population-based epidemiologic series of cases. Methods: The study population includes all ALS cases diagnosed in Piemonte, Italy, from January 2007 to June 2011. Mutations of SOD1, TARDBP, ANG, FUS, OPTN, and C9ORF72 have been assessed. Results: Out of the 475 patients included in the study, 51 (10.7%) carried a mutation of an ALS-related gene (C9ORF72, 32; SOD1, 10; TARDBP, 7; FUS, 1; OPTN, 1; ANG, none). A positive family history for ALS or frontotemporal dementia (FTD) was found in 46 (9.7%) patients. Thirty-one (67.4%) of the 46 familial cases and 20 (4.7%) of the 429 sporadic cases had a genetic mutation. According to logistic regression modeling, besides a positive family history for ALS or FTD, the chance to carry a genetic mutation was related to the presence of comorbid FTD (odds ratio 3.5; p = 0.001), and age at onset ≤54 years (odds ratio 1.79; p = 0.012). Conclusions: We have found that ∼11% of patients with ALS carry a genetic mutation, with C9ORF72 being the commonest genetic alteration. Comorbid FTD or a young age at onset are strong indicators of a possible genetic origin of the disease. PMID:23100398

  3. Robinson instability and beam loading

    SciTech Connect

    Craft, B.C. III

    1985-01-01

    The Robinson instability problem is developed in three stages. The first step is to derive the synchrotron oscillation equations in the absence of beam loading (unloaded case). Next, the equations are evaluated in the presence of beam loading at the fundamental rf frequency (statically loaded case). Finally, the system is redeveloped taking into account beam loading at the synchrotron sidebands (dynamically loaded case). Following the theoretical development, the results are applied to calculate the synchrotron frequency in the presence of beam-loading, automatic-gain-control, and automatic-tune-control. The results of this calculation are compared with data from the NSLS vuv-ring, a 750 MeV electron storage ring. 1 ref., 3 figs.

  4. Evaluation of Ti-48Al-2Nb Under Fretting Conditions

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Lerch, Bradley A.; Draper, Susan L.; Raj, Sai V.

    2001-01-01

    An investigation was conducted to examine the fretting behavior of lambda-TiAl (Ti-48Al-2Cr-2Nb) in contact with a nickel-base superalloy (Inconel 718) in air at temperatures from 23 to 550 C. Fretting wear experiments were conducted with 9.4-mm-diameter hemispherical Inconel (IN) 718 pins in contact with Ti-48Al-2Cr-2Nb flats (and the reverse) at loads from 1 to 40 N and fretting frequencies from 50 to 160 Hz with slip amplitudes from 50 to 200 microns for 1 to 20 million fretting cycles. The results were similar for both combinations of pin and flat. Reference fretting wear experiments were also conducted with 9.4-mm-diameter hemispherical Ti-6Al-4V pins in contact with IN718 flats. The interfacial adhesive bonds between Ti-48Al-2Cr-2Nb and IN718 in contact were generally stronger than the cohesive bonds in the cohesively weaker Ti-48Al-2Cr-2Nb. The failed Ti-48Al-2Cr-2Nb subsequently transferred to the IN718 surface at any fretting condition. The wear scars produced on Ti-48Al-2Cr-2Nb contained metallic and oxide wear debris, scratches, plastically deformed asperities, cracks, and fracture pits. Oxide layers readily formed on the Ti-48Al-2Cr-2Nb surface at 550 C, but cracks easily occurred in the oxide layers. Factors including fretting frequency, temperature, slip amplitude, and load influenced the fretting behavior of Ti-48Al-2Cr-2Nb in contact with IN718. The wear volume loss of Ti-48Al-2Cr-2Nb generally decreased with increasing fretting frequency. The increasing rate of oxidation at elevated temperatures up to 200 C led to a drop in wear volume loss at 200 C. However, the fretting wear increased as the temperature was increased from 200 to 550 C. The highest temperatures of 450 and 550 C resulted in oxide film disruption with generation of cracks, loose wear debris, and pits on the Ti-48Al-2Cr-2Nb wear surface. The wear volume loss generally increased as the slip amplitude increased. The wear volume loss also generally increased as the load increased

  5. Dynamic load balancing of applications

    DOEpatents

    Wheat, Stephen R.

    1997-01-01

    An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated.

  6. Dynamic load balancing of applications

    DOEpatents

    Wheat, S.R.

    1997-05-13

    An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers is disclosed. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated. 13 figs.

  7. Structural dynamics payload loads estimates

    NASA Technical Reports Server (NTRS)

    Engels, R. C.

    1982-01-01

    Methods for the prediction of loads on large space structures are discussed. Existing approaches to the problem of loads calculation are surveyed. A full scale version of an alternate numerical integration technique to solve the response part of a load cycle is presented, and a set of short cut versions of the algorithm developed. The implementation of these techniques using the software package developed is discussed.

  8. ALFA: Automated load forecasting assistant

    SciTech Connect

    Jabbour, K.; Riveros, J.F.V.; Landsbergen, D.; Meyer, W.

    1988-08-01

    ALFA, an expert system for forecasting short term demand for electricity is presented. ALFA is in operation at the new Energy Management System center at Niagara Mohawk Power Corporation in Upstate New York, generating the real time hourly load forecasts up to 48 hours in advance. ALFA uses an extensive 10 year historical data base of hourly observations of 12 weather variables and load, and a rule base that takes into account daily, weekly, and seasonal variations of load, as well as holidays, special events, and load growth. A satellite interface for the real-time acquisition of weather data, and the machine-operator interface are also discussed.

  9. Residential-appliance load characteristics

    NASA Astrophysics Data System (ADS)

    Kohler, J.

    1982-04-01

    The performance of residential photovoltaic systems in combination with energy efficient appliances is examined. The load characteristics are presented for several types of major residential appliances. Load characteristics consist of the average energy use of each appliance, the power demand while the appliance is operating, and a typical use schedule. Potential energy conserving features are investigated for each appliance and used to identify a best available model and maximum feasible energy efficient appliance. Load characteristics of these energy conserving designs are then compared with the load characteristics of a standard model. The feasibility of converting appliances to dc power for use with photovoltaic systems is also discussed.

  10. Estimating Nitrogen Loads, BMPs, and Target Loads Exceedance Risks

    EPA Science Inventory

    The Wabash River (WR) watershed, IN, drains two-thirds of the state’s 92 counties and has primarily agricultural land use. The nutrient and sediment loads of the WR significantly increase loads of the Ohio River ultimately polluting the Gulf of Mexico. The objective of this study...

  11. Crane-Load Contact Sensor

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert; Mata, Carlos; Cox, Robert

    2005-01-01

    An electronic instrument has been developed as a prototype of a portable crane-load contact sensor. Such a sensor could be helpful in an application in which the load rests on a base in a horizontal position determined by vertical alignment pins (see Figure 1). If the crane is not positioned to lift the load precisely vertically, then the load can be expected to swing once it has been lifted clear of the pins. If the load is especially heavy, large, and/or fragile, it could hurt workers and/or damage itself and nearby objects. By indicating whether the load remains in contact with the pins when it has been lifted a fraction of the length of the pins, the crane-load contact sensor helps the crane operator determine whether it is safe to lift the load clear of the pins: If there is contact, then the load is resting against the sides of the pins and, hence, it may not be safe to lift; if contact is occasionally broken, then the load is probably not resting against the pins, so it should be safe to lift. It is assumed that the load and base, or at least the pins and the surfaces of the alignment holes in the load, are electrically conductive, so the instrument can use electrical contact to indicate mechanical contact. However, DC resistance cannot be used as an indicator of contact for the following reasons: The load and the base are both electrically grounded through cables (the load is grounded through the lifting cable of the crane) to prevent discharge of static electricity. In other words, the DC resistance between the load and the pins is always low, as though they were always in direct contact. Therefore, instead of DC resistance, the instrument utilizes the AC electrical impedance between the pins and the load. The signal frequency used in the measurement is high enough (.1 MHz) that the impedance contributed by the cables and the electrical ground network of the building in which the crane and the base are situated is significantly greater than the contact

  12. Special Features of the Mechanical Characteristics of Al-Al2O3 Composites Produced By Explosive Compaction of Powders Under Shock-Wave Deformation

    NASA Astrophysics Data System (ADS)

    Zhukov, I. A.; Garkushin, G. V.; Vorozhtsov, S. A.; Khrustalyov, A. P.; Razorenov, S. V.; Kvetinskaya, A. V.; Promakhov, V. V.; Zhukov, A. S.

    2016-01-01

    The results obtained from investigations into the special features inherent in the mechanical characteristics (Hugoniot elastic limit and spall strength) observed under shock-wave loading of Al-Al2O3 composite samples produced by an explosive powder compaction technique are presented. Embedding 10 wt.% of aluminum oxide in the aluminum matrix has been found to increase the Hugoniot elastic limit as opposed to the commercialgrade AD1(Al 1013) aluminum alloy.

  13. Optimal load shedding and restoration

    NASA Astrophysics Data System (ADS)

    Xu, Ding

    Load shedding is an emergency control action in power systems that can save systems from a wide-area blackout. Underfrequency load shedding, steady state load shedding, and voltage load shedding are widely used in power systems. These methods utilize either the steady state model or a simplified dynamic model to represent a power systems. In this dissertation, a general optimal load shedding method that considers both the dynamic process and load distribution is proposed. The unfavorable load shedding is then formulated as an optimization problem with the objective function of cost minimization. This objective function is subjected to system, security, and operation constraints. The entire problem becomes a question of optimization with differential and nonlinear equations as constraints. To solve this problem, discretization is used to change the differential equations into algebraic equations. The original problem is thus reformulated as an optimization problem and can be solved by a standard mathematical program. The general idea is then applied to traditional power systems, deregulated power systems, power systems with distributed generation, and load restoration. In the traditional power system, the method shows that governor action, generation dynamic, disturbance location, and economic factors can be taken into consideration. In the deregulated power system, two power market models are developed and incorporated into the load shedding scheme. In power systems with multiple distributed generations, the different cases of disturbances are analyzed and models of different distributed generation developed. The general idea is then applied. Finally, the load restoration problem is studied, and it is proposed that an optimization method be applied to it. This dissertation provides a comprehensive solution for load shedding problem in power systems. The models developed in this research can also be used to study other power system problems.

  14. A review of the calculation procedure for critical acid loads for terrestrial ecosystems.

    PubMed

    van der Salm, C; de Vries, W

    2001-04-23

    Target loads for acid deposition in the Netherlands, as formulated in the Dutch environmental policy plan, are based on critical load calculations at the end of the 1980s. Since then knowledge on the effect of acid deposition on terrestrial ecosystems has substantially increased. In the early 1990s a simple mass balance model was developed to calculate critical loads. This model was evaluated and the methods were adapted to represent the current knowledge. The main changes in the model are the use of actual empirical relationships between Al and H concentrations in the soil solution, the addition of a constant base saturation as a second criterion for soil quality and the use of tree species-dependant critical Al/base cation (BC) ratios for Dutch circumstances. The changes in the model parameterisation and in the Al/BC criteria led to considerably (50%) higher critical loads for root damage. The addition of a second criterion in the critical load calculations for soil quality caused a decrease in the critical loads for soils with a median to high base saturation such as loess and clay soils. The adaptation hardly effected the median critical load for soil quality in the Netherlands, since only 15% of the Dutch forests occur on these soils. On a regional scale, however, critical loads were (much) lower in areas where those soils are located.

  15. Inexpensive Bolt-Load Gage

    NASA Technical Reports Server (NTRS)

    Long, M. J.

    1983-01-01

    "Built-in" gage determines whether large bolt or stud has been torqued to desired load and provides for continuous inspection to ensure proper load is being maintained. Gage detects longitudinal stress/strain bolt; requires no electronic or sonic test equipment.

  16. Spring loaded locator pin assembly

    DOEpatents

    Groll, Todd A.; White, James P.

    1998-01-01

    This invention deals with spring loaded locator pins. Locator pins are sometimes referred to as captured pins. This is a mechanism which locks two items together with the pin that is spring loaded so that it drops into a locator hole on the work piece.

  17. Spring loaded locator pin assembly

    DOEpatents

    Groll, T.A.; White, J.P.

    1998-03-03

    This invention deals with spring loaded locator pins. Locator pins are sometimes referred to as captured pins. This is a mechanism which locks two items together with the pin that is spring loaded so that it drops into a locator hole on the work piece. 5 figs.

  18. Perceptual Load Alters Visual Excitability

    ERIC Educational Resources Information Center

    Carmel, David; Thorne, Jeremy D.; Rees, Geraint; Lavie, Nilli

    2011-01-01

    Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism underlying these effects remains unclear. Here we tested an account attributing the effects of perceptual load to modulations of visual cortex excitability. In contrast to stimulus competition accounts, which propose that load…

  19. ALS superbend magnet system

    SciTech Connect

    Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

    2000-09-15

    The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

  20. Modulus measurements in ordered Co-Al, Fe-Al, and Ni-Al alloys

    NASA Technical Reports Server (NTRS)

    Harmouche, M. R.; Wolfenden, A.

    1985-01-01

    The composition and/or temperature dependence of the dynamic Young's modulus for the ordered B2 Co-Al, Fe-Al, and Ni-Al aluminides has been investigated using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The modulus has been measured in the composition interval 48.49 to 52.58 at. pct Co, 50.87 to 60.2 at. pct Fe, and 49.22 to 55.95 at. pct Ni for Co-Al, Fe-Al, and Ni-Al, respectively. The measured values for Co-Al are in the temperature interval 300 to 1300 K, while those for the other systems are for ambient temperature only. The data points show that Co-Al is stiffer than Fe-Al, which is stiffer than Ni-Al. The data points for Fe-Al and Ni-Al are slightly higher than those reported in the literature.

  1. Selecting a Control Strategy for Plug and Process Loads

    SciTech Connect

    Lobato, C.; Sheppy, M.; Brackney, L.; Pless, S.; Torcellini, P.

    2012-09-01

    Plug and Process Loads (PPLs) are building loads that are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the building occupants. PPLs in commercial buildings account for almost 5% of U.S. primary energy consumption. On an individual building level, they account for approximately 25% of the total electrical load in a minimally code-compliant commercial building, and can exceed 50% in an ultra-high efficiency building such as the National Renewable Energy Laboratory's (NREL) Research Support Facility (RSF) (Lobato et al. 2010). Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. A complex array of technologies that measure and manage PPLs has emerged in the marketplace. Some fall short of manufacturer performance claims, however. NREL has been actively engaged in developing an evaluation and selection process for PPLs control, and is using this process to evaluate a range of technologies for active PPLs management that will cap RSF plug loads. Using a control strategy to match plug load use to users' required job functions is a huge untapped potential for energy savings.

  2. Gas loading system for LANL two-stage gas guns

    NASA Astrophysics Data System (ADS)

    Gibson, Lee; Bartram, Brian; Dattelbaum, Dana; Lang, John; Morris, John

    2015-06-01

    A novel gas loading system was designed for the specific application of remotely loading high purity gases into targets for gas-gun driven plate impact experiments. The high purity gases are loaded into well-defined target configurations to obtain Hugoniot states in the gas phase at greater than ambient pressures. The small volume of the gas samples is challenging, as slight changing in the ambient temperature result in measurable pressure changes. Therefore, the ability to load a gas gun target and continually monitor the sample pressure prior to firing provides the most stable and reliable target fielding approach. We present the design and evaluation of a gas loading system built for the LANL 50 mm bore two-stage light gas gun. Targets for the gun are made of 6061 Al or OFHC Cu, and assembled to form a gas containment cell with a volume of approximately 1.38 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with corrosive gases. Piping and valves are stainless steel with wetted seals made from Kalrez and Teflon. Preliminary testing was completed to ensure proper flow rate and that the proper safety controls were in place. The system has been used to successfully load Ar, Kr, Xe, and anhydrous ammonia with purities of up to 99.999 percent. The design of the system, and example data from the plate impact experiments will be shown. LA-UR-15-20521

  3. Intercalation of both CTMAB and Al13 into montmorillonite.

    PubMed

    Zhu, Runliang; Wang, Tong; Ge, Fei; Chen, Wangxiang; You, Zhimin

    2009-07-01

    Clays intercalated with both organic cations and hydroxy-metal cations, also known as inorganic-organic clays (IOCs), have drawn great interests in the recent years because they possess the properties of both organoclays and pillared layered clays (PILCs). In this work, cetyltrimethyl ammonium bromide (CTMAB) and hydroxy-aluminum ([Al13O4(OH)24(H2O)12]7+ or Al13) were selected as the representatives of organic cations and hydroxy-metal cations, and three different methods were employed for the intercalation of montmorillonite at various CTMAB/Al13 ratios. This work aims to provide some novel information for clarifying the structural characteristics of IOCs. The experimental results showed that the structures of the resulting IOCs strongly depended on the intercalation methods and CTMAB/Al13 ratio. Both the intercalation agents could be intercalated into montmorillonite if they were used simultaneously for the intercalation, or if Al13 was intercalated after CTMAB, and the resulting IOCs were shown to have large basal spacing and small surface areas. However, if Al13 was intercalated first, the loading amounts of CTMAB would decrease significantly when the used Al13 amounts were relatively large (> or = 4 mmol Al/g montmorillonite). This could be attributed to the "lock" effect of montmorillonite's layers by the pre-intercalated Al13, and the basal spacing values of the resulting IOCs were shown to be equal to those of the PILCs. PMID:19394028

  4. Al Shanker Remembers.

    ERIC Educational Resources Information Center

    American Educator, 2000

    2000-01-01

    In a 1996 interview shortly before his death, Al Shanker, longtime president of the American Federation of Teachers, discussed such topics as: his own educational experiences; how he learned about political fighting in the Boy Scouts; the appeal of socialism; multinational corporations and the nation state; teaching tough students; and John Dewey…

  5. Fosetyl-al

    Integrated Risk Information System (IRIS)

    Fosetyl - al ; CASRN 39148 - 24 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  6. ALS renewal moves forward

    NASA Astrophysics Data System (ADS)

    Falcone, R. W.; Feinberg, B.; Hussain, Z.; Kirz, J.; Krebs, G. F.; Padmore, H. A.; Robin, D. S.; Robinson, A. L.

    2007-11-01

    As the result of an extensive long-term planning process involving all its stakeholders—management, staff, and users—the ALS has seen its future and is aggressively moving ahead to implement its vision for keeping the facility at the cutting edge for the next 2-3 decades. The evolving strategic plan now in place aims to renew the ALS so it can address a new generation of fundamental questions about size dependent and dimensional-confinement phenomena at the nanoscale; correlation and complexity in physical, biological, and environmental systems; and temporal evolution, assembly, dynamics and ultrafast phenomena. The renewal spans three areas: (1) increased staffing at beamlines to support the growing user community and safety professionals to keep an increasingly complex facility hazard free; (2) implementing advances in accelerator, insertion device, beamline, and detector technology that will make it possible for ALS users to address emerging grand scientific and technological challenges with incisive world-class tools; and (3) construction of a user support building and guest housing that will increase the safety and user friendliness of the ALS by providing users office, meeting, experiment staging, and laboratory space for their work and on-site accommodations at reasonable rates.

  7. Influence of varying compressive loading methods on physiologic motion patterns in the cervical spine.

    PubMed

    Bell, Kevin M; Yan, Yiguo; Debski, Richard E; Sowa, Gwendolyn A; Kang, James D; Tashman, Scott

    2016-01-25

    The human cervical spine supports substantial compressive load in-vivo arising from muscle forces and the weight of the head. However, the traditional in-vitro testing methods rarely include compressive loads, especially in investigations of multi-segment cervical spine constructs. Various methods of modeling physiologic loading have been reported in the literature including axial forces produced with inclined loading plates, eccentric axial force application, follower load, as well as attempts to individually apply/model muscle forces in-vitro. The importance of proper compressive loading to recreate the segmental motion patterns exhibited in-vivo has been highlighted in previous studies. However, appropriate methods of representing the weight of head and muscle loading are currently unknown. Therefore, a systematic comparison of standard pure moment with no compressive loading versus published and novel compressive loading techniques (follower load - FL, axial load - AL, and combined load - CL) was performed. The present study is unique in that a direct comparison to continuous cervical kinematics over the entire extension to flexion motion path was possible through an ongoing intra-institutional collaboration. The pure moment testing protocol without compression or with the application of follower load was not able to replicate the typical in-vivo segmental motion patterns throughout the entire motion path. Axial load or a combination of axial and follower load was necessary to mimic the in-vivo segmental contributions at the extremes of the extension-flexion motion path. It is hypothesized that dynamically altering the compressive loading throughout the motion path is necessary to mimic the segmental contribution patterns exhibited in-vivo. PMID:26708967

  8. Immediate loading of dental implants.

    PubMed

    Henry, P J; Liddelow, G J

    2008-06-01

    The purpose of this review is to explore the concept of immediate loading as it pertains to dental implants and the indications for clinical practice. The definition of immediate loading will be considered together with a review of the relevant literature in an attempt to provide evidence-based guidelines for successful implementation into practice. A search of electronic databases including Medline, PubMed and the Cochrane Database of Systematic Reviews was undertaken using the terms "immediate loading'', "dental implants'', "immediate function'', "early loading'', "oral implants'', "immediate restoration'' and "systematic review''. This was supplemented by handsearching in peer-reviewed journals and cross-referenced with the articles accessed. Emphasis was given to systematic reviews and controlled clinical trials. A definition of immediate loading was suggested pertinent to the realities of logistics in clinical practice with respect to application and time frame. The literature was evaluated and shown to be limited with significant shortcomings. Guidelines and recommendations for clinical protocols were suggested and illustrated by examples of case types with a minimum of 1-3 years follow-up. A list of additional references for further reading was provided. Within the limitations of this review, there is evidence to suggest that immediate loading protocols have demonstrated high implant survival rates and may be cautiously recommended for certain clinical situations. However, more high level evidence studies, preferably randomized controlled trials (RCTs), over a long time frame are required to show a clear benefit over more conventional loading protocols.

  9. Multipactor discharge in a dielectric-loaded accelerating structure

    NASA Astrophysics Data System (ADS)

    Wu, L.; Ang, L. K.

    2007-01-01

    This paper presents a Monte-Carlo model to explain the multipactor discharge and its high-power absorption in a dielectric-loaded accelerating (DLA) structure reported recently [J. G. Power et al., Phys. Rev. Lett. 92, 164801 (2004)]. Susceptibility diagrams are constructed. Dynamic calculations for beam loading and its power absorption by the multipactor discharge are performed. It is found that the fraction of power absorbed by multipactor discharge at saturation is much larger than the case of a simple rf window, and it is sensitive to the incident power, which confirms the prior experimental results. This enhanced power absorption is due to the fact that the length of a DLA structure is much larger than the radius of the structure. A resonant condition of a maximum growth region has also been determined numerically and analytically. The difference between the resonant condition and saturation (due to beam loading) is clarified.

  10. Mechanical behaviour of TWIP steel under shear loading

    NASA Astrophysics Data System (ADS)

    Vincze, G.; Butuc, M. C.; Barlat, F.

    2016-08-01

    Twinning induced plasticity steels (TWIP) are very good candidate for automotive industry applications because they potentially offer large energy absorption before failure due to their exceptional strain hardening capability and high strength. However, their behaviour is drastically influenced by the loading conditions. In this work, the mechanical behaviour of a TWIP steel sheet sample was investigated at room temperature under monotonic and reverse simple shear loading. It was shown that all the expected features of load reversal such as Bauschinger effect, transient strain hardening with high rate and permanent softening, depend on the prestrain level. This is in agreement with the fact that these effects, which occur during reloading, are related to the rearrangement of the dislocation structure induced during the predeformation. The homogeneous anisotropic hardening (HAH) approach proposed by Barlat et al. (2011) [1] was successfully employed to predict the experimental results.

  11. Space Shuttle fatigue loads spectra for prelaunch and liftoff loads

    NASA Technical Reports Server (NTRS)

    Goldish, Judith; Ortasse, Raphael

    1994-01-01

    Fatigue loads spectra for the prelaunch and liftoff flight segments of the Space Shuttle were developed. A variety o methods were used to determine the distributions of several important parameters, such as time of exposure on the launch, pad, month of launch, and wind speed. Also, some lessons learned that would be applicable to development of fatigue loads spectra for other reusable space vehicles are presented.

  12. Hydrodynamic loading of tensegrity structures

    NASA Astrophysics Data System (ADS)

    Wroldsen, Anders S.; Johansen, Vegar; Skelton, Robert E.; Sørensen, Asgeir J.

    2006-03-01

    This paper introduces hydrodynamic loads for tensegrity structures, to examine their behavior in marine environments. Wave compliant structures are of general interest when considering large marine structures, and we are motivated by the aquaculture industry where new concepts are investigated in order to make offshore installations for seafood production. This paper adds to the existing models and software simulations of tensegrity structures exposed to environmental loading from waves and current. A number of simulations are run to show behavior of the structure as a function of pretension level and string stiffness for a given loading condition.

  13. Spinning Reserve from Responsive Load

    SciTech Connect

    Kueck, John D; Kirby, Brendan J; Laughner, T; Morris, K

    2009-01-01

    As power system costs rise and capacity is strained demand response can provide a significant system reliability benefit at a potentially attractive cost. The 162 room Music Road Hotel in Pigeon Forge Tennessee agreed to host a spinning reserve test. The Tennessee Valley Authority (TVA) supplied real-time metering and monitoring expertise to record total hotel load during both normal operations and testing. Preliminary testing showed that hotel load can be curtailed by 22% to 37% depending on the outdoor temperature and the time of day. The load drop was very rapid, essentially as fast as the 2 second metering could detect.

  14. Mesoscale Studies of Mixing in Reactive Materials During Shock Loading

    NASA Astrophysics Data System (ADS)

    Lomov, Ilya; Herbold, Eric

    2011-06-01

    One of the requisite processes for reactions between solid powder particles resulting from shock loading is that they undergo large deformations, exposing new surfaces while mixing with surrounding material. The deformability of Al particles on the scale of hundreds of nanometers to several microns with an oxide layer or Ni coating during shock loading is investigated. Mesoscale simulations with an Eulerian hydrocode GEODYN show enhanced fracture of the outside layer of the Al particles when even small volume fractions of a larger or dense material is added to the mixture. Rate of reactions in solid-solid mixtures is not a unique function of pressure, temperature and the plastic strain. Reactions under shock loading happen in reaction zone, which extent is defined by the surface of interfacial area and the depth of the diffusion layer. The former depends on the level of hydrodynamic mixing of heterogeneous material under shock, while the latter depends on the temperature-dependent species diffusion. These processes introduce time and length scales onto the problem. To study diffusion-limited reactions on the grain scale level, material diffusion and a simple reaction kinetic which depends on the interfacial surface area is implemented in GEODYN. Several scenarios of diffusion-reaction processes initiated by shock loading in loose or consolidated powders with initially well- defined material interfaces are considered.

  15. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  16. 14 CFR 23.425 - Gust loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Balancing Surfaces § 23.425 Gust loads. (a) Each horizontal surface, other than a main wing, must be... for the conditions specified in paragraph (a) of this section, the initial balancing loads for steady... load resulting from the gusts must be added to the initial balancing load to obtain the total load....

  17. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  18. Estimating Demand Response Load Impacts: Evaluation of BaselineLoad Models for Non-Residential Buildings in California

    SciTech Connect

    Coughlin, Katie; Piette, Mary Ann; Goldman, Charles; Kiliccote,Sila

    2008-01-01

    variability, all BLPmodels perform reasonably well in accuracy. - For customer accounts withhighly variable loads, we found that no BLP model produced satisfactoryresults, although averaging methods perform best in accuracy (but notbias). These types of customers are difficult to characterize withstandard BLP models that rely on historic loads and weather data.Implications of these results for DR program administrators andpolicymakersare: - Most DR programs apply similar DR BLP methods tocommercial and industrial sector customers. The results of our study whencombined with other recent studies (Quantum 2004 and 2006, Buege et al.,2006) suggests that DR program administrators should have flexibility andmultiple options for suggesting the most appropriate BLP method forspecific types of customers.

  19. Loading and conjugating cavity biostructures

    DOEpatents

    Hainfeld, J.F.

    1995-08-22

    Methods for the preparation and use of a biological delivery system are disclosed. The method of preparation includes the loading of a non-biological material into a biostructure having a load-bearing structure. The method also includes the removal of some of the biostructure`s contents and the loading of a non-biological material into the biostructure. The biostructure is biologically compatible with the host, and preferably is derived from the host, the host`s species or a related species. The loaded biostructure is used directly, or it can be targeted to specific cells, tissues and/or organs within a host. The targeted biostructure can be used to deliver the non-biological material to a specified tissue, organ or cell within a host for diagnostic, therapeutic or other purposes. 11 figs.

  20. Loading and conjugating cavity biostructures

    DOEpatents

    Hainfeld, James F.

    1997-11-25

    Methods for the preparation and use of a biological delivery system are disclosed. The method of preparation includes the loading of a non-biological material into a biostructure having a load-bearing structure. The method also includes the removal of some of the biostructure's contents and the loading of a non-biological material into the biostructure. The biostructure is biologically compatible with the host, and preferably is derived from the host, the host's species or a related species. The loaded biostructure is used directly, or it can be targeted to specific cells, tissues and/or organs within a host. The targeted biostructure can be used to deliver the non-biological material to a specified tissue, organ or cell within a host for diagnostic, therapeutic or other purposes.

  1. Loading and conjugating cavity biostructures

    DOEpatents

    Hainfeld, James F.

    1995-08-22

    Methods for the preparation and use of a biological delivery system are disclosed. The method of preparation includes the loading of a non-biological material into a biostructure having a load-bearing structure. The method also includes the removal of some of the biostructure's contents and the loading of a non-biological material into the biostructure. The biostructure is biologically compatible with the host, and preferably is derived from the host, the host's species or a related species. The loaded biostructure is used directly, or it can be targeted to specific cells, tissues and/or organs within a host. The targeted biostructure can be used to deliver the non-biological material to a specified tissue, organ or cell within a host for diagnostic, therapeutic or other purposes.

  2. Loading and conjugating cavity biostructures

    DOEpatents

    Hainfeld, J.F.

    1997-11-25

    Methods for the preparation and use of a biological delivery system are disclosed. The method of preparation includes the loading of a non-biological material into a biostructure having a load-bearing structure. The method also includes the removal of some of the biostructure`s contents and the loading of a non-biological material into the biostructure. The biostructure is biologically compatible with the host, and preferably is derived from the host, the host`s species or a related species. The loaded biostructure is used directly, or it can be targeted to specific cells, tissues and/or organs within a host. The targeted biostructure can be used to deliver the non-biological material to a specified tissue, organ or cell within a host for diagnostic, therapeutic or other purposes. 11 figs.

  3. Sandia Wind Turbine Loads Database

    DOE Data Explorer

    The Sandia Wind Turbine Loads Database is divided into six files, each corresponding to approximately 16 years of simulation. The files are text files with data in columnar format. The 424MB zipped file containing six data files can be downloaded by the public. The files simulate 10-minute maximum loads for the NREL 5MW wind turbine. The details of the loads simulations can be found in the paper: “Decades of Wind Turbine Loads Simulations”, M. Barone, J. Paquette, B. Resor, and L. Manuel, AIAA2012-1288 (3.69MB PDF). Note that the site-average wind speed is 10 m/s (class I-B), not the 8.5 m/s reported in the paper.

  4. NASA Dryden Flight Loads Laboratory

    NASA Technical Reports Server (NTRS)

    Horn, Tom

    2008-01-01

    This viewgraph presentation reviews the work of the Dryden Flight Loads Laboratory. The capabilities and research interests of the lab are: Structural, thermal, & dynamic analysis; Structural, thermal, & dynamic ground-test techniques; Advanced structural instrumentation; and Flight test support.

  5. Plutonium Immobilization Can Loading Concepts

    SciTech Connect

    Kriikku, E.; Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.; Rogers, L.; Fiscus, J.; Dyches, G.

    1998-05-01

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses five can loading conceptual designs and the lists the advantages and disadvantages for each concept. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas. The can loading welder and cutter are very similar to the existing Savannah River Site (SRS) FB-Line bagless transfer welder and cutter and thus they are a low priority development item.

  6. Maximizing TDRS Command Load Lifetime

    NASA Technical Reports Server (NTRS)

    Brown, Aaron J.

    2002-01-01

    The GNC software onboard ISS utilizes TORS command loads, and a simplistic model of TORS orbital motion to generate onboard TORS state vectors. Each TORS command load contains five "invariant" orbital elements which serve as inputs to the onboard propagation algorithm. These elements include semi-major axis, inclination, time of last ascending node crossing, right ascension of ascending node, and mean motion. Running parallel to the onboard software is the TORS Command Builder Tool application, located in the JSC Mission Control Center. The TORS Command Builder Tool is responsible for building the TORS command loads using a ground TORS state vector, mirroring the onboard propagation algorithm, and assessing the fidelity of current TORS command loads onboard ISS. The tool works by extracting a ground state vector at a given time from a current TORS ephemeris, and then calculating the corresponding "onboard" TORS state vector at the same time using the current onboard TORS command load. The tool then performs a comparison between these two vectors and displays the relative differences in the command builder tool GUI. If the RSS position difference between these two vectors exceeds the tolerable lim its, a new command load is built using the ground state vector and uplinked to ISS. A command load's lifetime is therefore defined as the time from when a command load is built to the time the RSS position difference exceeds the tolerable limit. From the outset of TORS command load operations (STS-98), command load lifetime was limited to approximately one week due to the simplicity of both the onboard propagation algorithm, and the algorithm used by the command builder tool to generate the invariant orbital elements. It was soon desired to extend command load lifetime in order to minimize potential risk due to frequent ISS commanding. Initial studies indicated that command load lifetime was most sensitive to changes in mean motion. Finding a suitable value for mean motion

  7. Measured electric hot water standby and demand loads from Pacific Northwest homes. End-Use Load and Consumer Assessment Program

    SciTech Connect

    Pratt, R.G.; Ross, B.A.

    1991-11-01

    The Bonneville Power Administration began the End-Use Load and Consumer Assessment Program (ELCAP) in 1983 to obtain metered hourly end-use consumption data for a large sample of new and existing residential and commercial buildings in the Pacific Northwest. Loads and load shapes from the first 3 years of data fro each of several ELCAP residential studies representing various segments of the housing population have been summarized by Pratt et al. The analysis reported here uses the ELCAP data to investigate in much greater detail the relationship of key occupant and tank characteristics to the consumption of electricity for water heating. The hourly data collected provides opportunities to understand electricity consumption for heating water and to examine assumptions about water heating that are critical to load forecasting and conservation resource assessments. Specific objectives of this analysis are to: (A) determine the current baseline for standby heat losses by determining the standby heat loss of each hot water tank in the sample, (B) examine key assumptions affecting standby heat losses such as hot water temperatures and tank sizes and locations, (C) estimate, where possible, impacts on standby heat losses by conservation measures such as insulating tank wraps, pipe wraps, anticonvection valves or traps, and insulating bottom boards, (D) estimate the EF-factors used by the federal efficiency standards and the nominal R-values of the tanks in the sample, (E) develop estimates of demand for hot water for each home in the sample by subtracting the standby load from the total hot water load, (F) examine the relationship between the ages and number of occupants and the hot water demand, (G) place the standby and demand components of water heating electricity consumption in perspective with the total hot water load and load shape.

  8. PLUTONIUM LOADING CAPACITY OF REILLEX HPQ ANION EXCHANGE COLUMN - AFS-2 PLUTONIUM FLOWSHEET FOR MOX

    SciTech Connect

    Kyser, E.; King, W.; O'Rourke, P.

    2012-07-26

    Radioactive plutonium (Pu) anion exchange column experiments using scaled HB-Line designs were performed to investigate the dependence of column loading performance on the feed composition in the H-Canyon dissolution process for plutonium oxide (PuO{sub 2}) product shipped to the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). These loading experiments show that a representative feed solution containing {approx}5 g Pu/L can be loaded onto Reillex{trademark} HPQ resin from solutions containing 8 M total nitrate and 0.1 M KF provided that the F is complexed with Al to an [Al]/[F] molar ratio range of 1.5-2.0. Lower concentrations of total nitrate and [Al]/[F] molar ratios may still have acceptable performance but were not tested in this study. Loading and washing Pu losses should be relatively low (<1%) for resin loading of up to 60 g Pu/L. Loading above 60 g Pu/L resin is possible, but Pu wash losses will increase such that 10-20% of the additional Pu fed may not be retained by the resin as the resin loading approaches 80 g Pu/L resin.

  9. Ausbildung als zentrale Aufgabe

    NASA Astrophysics Data System (ADS)

    Krämer, Walter; Schmerbach, Sibylle

    Anders als Lesen und Schreiben zählen Grundkenntnisse in Statistik heute noch nicht zu den Voraussetzungen einer sinnvollen Teilhabe am Sozialgeschehen. Und auch in der akademischen Statistik-Ausbildung gibt es noch einiges zu tun. Das vorliegende Kapitel zeichnet die Geschichte dieser akademischen Ausbildung an deutschen Universitäten nach dem zweiten Weltkrieg nach, stellt aktuelle Defizite vor und weist auf mögliche Verbesserungen hin.

  10. Split torque transmission load sharing

    NASA Technical Reports Server (NTRS)

    Krantz, T. L.; Rashidi, M.; Kish, J. G.

    1992-01-01

    Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears.

  11. Drug Loading of Mesoporous Silicon

    NASA Astrophysics Data System (ADS)

    Moffitt, Anne; Coffer, Jeff; Wang, Mengjia

    2011-03-01

    The nanostructuring of crystalline solids with low aqueous solubilities by their incorporation into mesoporous host materials is one route to improve the bioavailability of such solids. Earlier studies suggest that mesoporous Si (PSi), with pore widths in the range of 5-50 nm, is a candidate for such an approach. In this presentation, we describe efforts to load curcumin into free-standing microparticles of PSi. Curcumin is a compound extracted from turmeric root, which is an ingredient of curry. Curucmin has shown activity against selected cancer cell lines, bacteria, and other medical conditions. However, curcumin has a very low bioavailability due to its extremely low water solubility (0.6 μ g/mL). Incorporation of curcumin was achieved by straightforward loading of the molten solid at 185circ; C. Loading experiments were performed using PSi particles of two different size ranges, 45-75 μ m and 150-250 μ m. Longer loading times and ratio of curcumin to PSi leads to a higher percentage of loaded curcumin in both PSi particle sizes (as determined by weight difference). The extent of curcumin crystallinity was assessed by x-ray diffraction (XRD). The solubility and release kinetics of loaded curcumin from the PSi was determined by extraction into water at 37circ; C, with analysis using UV-VIS spectrometry. NSF-REU and TCU.

  12. 14 CFR 23.507 - Jacking loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) Vertical-load factor of 1.35 times the static reactions. (2) Fore, aft, and lateral load factors of 0.4 times the vertical static reactions. (b) The horizontal loads at the jack points must be reacted...

  13. 14 CFR 23.507 - Jacking loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Vertical-load factor of 1.35 times the static reactions. (2) Fore, aft, and lateral load factors of 0.4 times the vertical static reactions. (b) The horizontal loads at the jack points must be reacted...

  14. 14 CFR 23.507 - Jacking loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) Vertical-load factor of 1.35 times the static reactions. (2) Fore, aft, and lateral load factors of 0.4 times the vertical static reactions. (b) The horizontal loads at the jack points must be reacted...

  15. 14 CFR 23.507 - Jacking loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Vertical-load factor of 1.35 times the static reactions. (2) Fore, aft, and lateral load factors of 0.4 times the vertical static reactions. (b) The horizontal loads at the jack points must be reacted...

  16. 14 CFR 23.537 - Seawing loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.537 Seawing loads. Seawing design loads must be based on applicable test data. Emergency Landing Conditions...

  17. 14 CFR 23.537 - Seawing loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.537 Seawing loads. Seawing design loads must be based on applicable test data. Emergency Landing Conditions...

  18. 14 CFR 23.507 - Jacking loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) Vertical-load factor of 1.35 times the static reactions. (2) Fore, aft, and lateral load factors of 0.4 times the vertical static reactions. (b) The horizontal loads at the jack points must be reacted...

  19. The effects of load drop, uniform load and concentrated loads on waste tanks

    SciTech Connect

    Marusich, R.M., Westinghouse Hanford

    1996-09-06

    This document provides the supporting calculations performed by others specifically for the TWRS FSAR and more detailed summaries of the important references issued in the past regarding the effects of various loads.

  20. The effects of load drop, uniform load and concentrated loads on waste tanks

    SciTech Connect

    Marusich, R.M.

    1996-09-27

    This document provides the supporting calculations performed by others specifically for the TWRS FSAR and more detailed summaries of the important references issued in the past regarding the effects of various loads.

  1. Guidelines for transmission line structural loading

    SciTech Connect

    Not Available

    1984-01-01

    This guide provides methods for the selection of design loads and load factors. This is accomplished by the presentation of a Load Resistance Factor Design (LRFD) procedure. The basic formula for wind force is discussed. This include basic wind speed, terrain and height coefficients, gust response factors, and pressure coefficients. Information is also provided on ice loads, tornadoes, hurricanes, longitudinal loads, construction, and maintenance loads.

  2. Effects of Vibration and G-Loading on Heart Rate, Breathing Rate, and Response Time

    NASA Technical Reports Server (NTRS)

    Godinez, Angelica; Ayzenberg, Ruthie; Liston, Dorian B.; Stone, Leland S.

    2013-01-01

    Aerospace and applied environments commonly expose pilots and astronauts to G-loading and vibration, alone and in combination, with well-known sensorimotor (Cohen, 1970) and performance consequences (Adelstein et al., 2008). Physiological variables such as heart rate (HR) and breathing rate (BR) have been shown to increase with G-loading (Yajima et al., 1994) and vibration (e.g. Guignard, 1965, 1985) alone. To examine the effects of G-loading and vibration, alone and in combination, we measured heart rate and breathing rate under aerospace-relevant conditions (G-loads of 1 Gx and 3.8 Gx; vibration of 0.5 gx at 8, 12, and 16 Hz).

  3. Peak load management: Potential options

    SciTech Connect

    Englin, J.E.; De Steese, J.G.; Schultz, R.W.; Kellogg, M.A.

    1989-10-01

    This report reviews options that may be alternatives to transmission construction (ATT) applicable both generally and at specific locations in the service area of the Bonneville Power Administration (BPA). Some of these options have potential as specific alternatives to the Shelton-Fairmount 230-kV Reinforcement Project, which is the focus of this study. A listing of 31 peak load management (PLM) options is included. Estimated costs and normalized hourly load shapes, corresponding to the respective base load and controlled load cases, are considered for 15 of the above options. A summary page is presented for each of these options, grouped with respect to its applicability in the residential, commercial, industrial, and agricultural sectors. The report contains comments on PLM measures for which load shape management characteristics are not yet available. These comments address the potential relevance of the options and the possible difficulty that may be encountered in characterizing their value should be of interest in this investigation. The report also identifies options that could improve the efficiency of the three customer utility distribution systems supplied by the Shelton-Fairmount Reinforcement Project. Potential cogeneration options in the Olympic Peninsula are also discussed. These discussions focus on the options that appear to be most promising on the Olympic Peninsula. Finally, a short list of options is recommended for investigation in the next phase of this study. 9 refs., 24 tabs.

  4. A gravity loading countermeasure skinsuit

    NASA Astrophysics Data System (ADS)

    Waldie, James M.; Newman, Dava J.

    2011-04-01

    Despite the use of several countermeasures, significant physiological deconditioning still occurs during long duration spaceflight. Bone loss - primarily due to the absence of loading in microgravity - is perhaps the greatest challenge to resolve. This paper describes a conceptual Gravity Loading Countermeasure Skinsuit (GLCS) that induces loading on the body to mimic standing and - when integrated with other countermeasures - exercising on Earth. Comfort, mobility and other operational issues were explored during a pilot study carried out in parabolic flight for prototype suits worn by three subjects. Compared to the 1- or 2-stage Russian Pingvin Suits, the elastic mesh of the GLCS can create a loading regime that gradually increases in hundreds of stages from the shoulders to the feet, thereby reproducing the weight-bearing regime normally imparted by gravity with much higher resolution. Modelling shows that the skinsuit requires less than 10 mmHg (1.3 kPa) of compression for three subjects of varied gender, height and mass. Negligible mobility restriction and excellent comfort properties were found during the parabolic flights, which suggests that crewmembers should be able to work normally, exercise or sleep while wearing the suit. The suit may also serve as a practical 1 g harness for exercise countermeasures and vibration applications to improve dynamic loading.

  5. Friction and anchorage loading revisited.

    PubMed

    Dholakia, Kartik D

    2012-01-01

    Contemporary concepts of sliding mechanics explain that friction is inevitable. To overcome this frictional resistance, excess force is required to retract the tooth along the archwire (ie, individual retraction of canines, en masse retraction of anterior teeth), in addition to the amount of force required for tooth movement. The anterior tooth retraction force, in addition to excess force (to overcome friction), produces reciprocal protraction force on molars, thereby leading to increased anchorage loading. However, this traditional concept was challenged in recent literature, which was based on the finite element model, but did not bear correlation to the clinical scenario. This article will reinforce the fact that clinically, friction increases anchorage loading in all three planes of space, considering the fact that tooth movement is a quasistatic process rather than a purely continuous or static one, and that conventional ways of determining the effects of static or dynamic friction on anchorage load cannot be applied to clinical situations (which consist of anatomical resistance units and a complex muscular force system). The article does not aim to quantify friction and its effect on the amount of anchorage load. Rather, a new perspective regarding the role of various additional factors (which is not explained by contemporary concept) that may influence friction and anchorage loading is provided..

  6. Evaluating Daily Load Stimulus Formulas in Relating Bone Response to Exercise

    NASA Technical Reports Server (NTRS)

    Pennline, James A.; Mulugeta, Lealem

    2014-01-01

    Six formulas representing what is commonly referred to as "daily load stimulus" are identified, compared and tested in their ability to relate skeletal mechanical loading to bone maintenance and osteogenic response. Particular emphasis is placed on exercise- induced skeletal loading and whether or not the formulas can adequately capture the known experimental observations of saturation of continuous cyclic loading, rest insertion between repetitions (cycles), recovery of osteogenic potential following saturation, and multiple shorter bouts versus a single long bout of exercise. To evaluate the ability of the formulas to capture these characteristics, a set of exercise scenarios with type of exercise bout, specific duration, number of repetitions, and rest insertion between repetitions is defined. The daily load values obtained from the formulas for the loading conditions of the set of scenarios is illustrated. Not all of the formulas form estimates of daily load in units of stress or in terms of strain at a skeletal site due to the loading force from a specific exercise prescription. The comparative results show that none of the formulas are able to capture all of the experimentally observed characteristics of cyclic loading. However, the enhanced formula presented by Genc et al. does capture several characteristics of cyclic loading that the others do not, namely recovery of osteogenic potential and saturation. This could be a basis for further development of mathematical formulas that more adequately approximates the amount of daily stress at a skeletal site that contributes to bone adaptation.

  7. AL Amyloidosis and Agent Orange

    MedlinePlus

    ... for survivors' benefits . Research on AL amyloidosis and herbicides The Health and Medicine Division (formally known as ... to the compounds of interest found in the herbicide Agent Orange and AL amyloidosis." VA made a ...

  8. Modeling neuronal vulnerability in ALS.

    PubMed

    Roselli, Francesco; Caroni, Pico

    2014-08-20

    Using computational models of motor neuron ion fluxes, firing properties, and energy requirements, Le Masson et al. (2014) reveal how local imbalances in energy homeostasis may self-amplify and contribute to neurodegeneration in ALS.

  9. The Shock Hugoniot of the Intermetallic Compound Ni3Al

    SciTech Connect

    Knapp, I.; Millett, J. C. F.; Meziere, Y. J. E.; Gray, G. T. III; Bourne, N. K.

    2006-07-28

    The behaviour of the intermetallic compound, Ni3Al under shock loading conditions has been measured. The Hugoniot Elastic Limit occurs at ca. 530 MPa, which converts to a 1-D yield stress of 273 MPa, in agreement with quasi-static data. In contrast, the ductility at shock-induced strain-rates appears much reduced when compared to lower strain-rates. The Hugoniot in terms of shock velocity and particle velocity suggests that Ni3Al is more compressible than pure nickel. This is in agreement with the greater stiffnesses in nickel, measured using ultrasonic techniques.

  10. The Bauschinger effect in a SiC/Al composite

    SciTech Connect

    Shi, N.; Pillai, U.T.S.; Arsenault, R.J.

    1995-09-01

    SiC/Al composites have interesting mechanical properties, the tensile yield stress, whereas, the apparent modulus in tension is greater than that in compression. The Bauschinger effect of SiC/Al composites is also asymmetric with regard to loading directions. Quantitative measurements of the asymmetry of composite Bauschinger Effect was made in this research . An investigation was undertaken to determine the origin of the asymmetrical Bauschinger effect. We have successfully reconstructed the observed asymmetry using an internal stress model based on the development of internal stresses, conveniently referred to as the ``black stress``, and work hardening.

  11. Al Jazirah, Sudan

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Al Jazirah (also Gezira) is one of the 26 states of Sudan. The state lies between the Blue Nile and the White Nile in the east-central region of the country. It is a well populated area suitable for agriculture. The area was at the southern end of Nubia and little is known about its ancient history and only limited archaeological work has been conducted in this area. The region has benefited from the Gezira Scheme, a program to foster cotton farming begun in 1925. At that time the Sennar Dam and numerous irrigation canals were built. Al Jazirah became the Sudan's major agricultural region with more than 2.5 million acres (10,000 km) under cultivation. The initial development project was semi-private, but the government nationalized it in 1950. Cotton production increased in the 1970s but by the 1990s increased wheat production has supplanted a third of the land formerly seeded with cotton.

    The image was acquired December 25, 2006, covers an area of 56 x 36.4 km, and is located near 14.5 degrees north latitude, 33.1 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  12. Scientific ballooning payload termination loads

    NASA Astrophysics Data System (ADS)

    Robbins, E.

    1993-02-01

    NASA's high altitude balloon borne scientific payloads are typically suspended from a deployed flat circular parachute. At flight termination, the recovery train is pyrotechnically separated at the parachute apex and balloon nadir interface. The release of elastic energy stored in the parachute at zero initial virtical velocity in the rarefied atmosphere produces high canopy opening forces that subject the gondola to potentially damaging shock loads. Data from terminations occuring at altitudes to 40 km with payloads up to 2500 kg on parachutes up to 40 m in diameter are presented. Measured loads are markedly larger than encountered via packed parachute deployment for similar canopy loadings. Canopy inflation is significantly surpressed in the early stages and then accelerated during final blossoming. Data interpretation and behavioral phenomena are discussed along with proposed shock attenuation techniques.

  13. Load Diffusion in Composite Structures

    NASA Technical Reports Server (NTRS)

    Horgan, Cornelius O.; Simmonds, J. G.

    2000-01-01

    This research has been concerned with load diffusion in composite structures. Fundamental solid mechanics studies were carried out to provide a basis for assessing the complicated modeling necessary for large scale structures used by NASA. An understanding of the fundamental mechanisms of load diffusion in composite subcomponents is essential in developing primary composite structures. Analytical models of load diffusion behavior are extremely valuable in building an intuitive base for developing refined modeling strategies and assessing results from finite element analyses. The decay behavior of stresses and other field quantities provides a significant aid towards this process. The results are also amendable to parameter study with a large parameter space and should be useful in structural tailoring studies.

  14. Fifty years of genetic load

    SciTech Connect

    Wallace, B.

    1991-01-01

    This book discusses the radiation effects on Drosophila. It was originally thought that irradiating Drosophila would decrease the average fitness of the population, thereby leading to information about the detrimental effects of mutations. Surprisingly, the fitness of the irradiated population turned out to be higher than that of the control population. The original motivation for the experiment was as a test of genetic load theory. The average fitness of a population is depressed by deleterious alleles held in the population by the balance between mutation and natural selection. The depression is called the genetic load of the population. The load dose not depend on the magnitude of the deleterious effect of alleles, but only on the mutation rate.

  15. Plutonium Immobilization Project -- Can loading

    SciTech Connect

    Kriikku, E.

    2000-01-18

    The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP scope includes unloading transportation containers, preparing the feed streams, converting the metal feed to an oxide, adding the ceramic precursors, pressing the pucks, inspecting pucks, and sintering pucks. The PIP scope also includes loading the pucks into metal cans, sealing the cans, inspecting the cans, loading the cans into magazines, loading magazines into Defense Waste Processing Facility (DWPF) canisters, and transporting the canisters to the DWPF. The DWPF fills the canister with a mixture of high level radioactive waste and glass for permanent storage. Due to the radiation, remote equipment must perform PIP operations in a contained environment.

  16. Numerical simulation of ice-load induced salt movements

    NASA Astrophysics Data System (ADS)

    Lang, Joerg; Al-Hseinat, Muayyad; Brandes, Christian; Hampel, Andrea; Hübscher, Christian; Winsemann, Jutta

    2015-04-01

    A correlation between salt structures, glacigenic features and faulting of Pleistocene deposits above salt structures has been recognised in many places of the formerly glaciated areas in northern central Europe and attributed to ice-sheet loading. Conceptual models predict that the load applied by an ice sheet will favour ice-marginal salt rise and obstruct salt rise beneath the ice sheet (e.g., Liszkowski, 1993). To test these models, we simulated the response of salt structures to ice-sheet loading using a 2D finite-element model (ABAQUS). The subsurface geometries used in our models are based on regional geological cross-sections and 2D seismic profiles of salt structures in the Central European Basin System. The model layers represent (i) sedimentary rocks of elastoplastic rheology, (ii) a viscoelastic salt structure and (iii) elastoplastic basement rocks. At the model surface a temporarily and spatially variable pressure simulates ice-sheet loading. All our simulations show a response of salt structures to ice-sheet loading, which strongly depends on the location of the ice margin relative to the salt structure. Salt structures rise in front of the ice margin (up to 4 m), if load is applied to the salt source layer. Beneath an ice sheet salt structures are pushed down (up to 36 m). Much of the subglacial downwards displacement is compensated by a reversal of the movement during ice retreat. The resulting surface displacements are therefore rather low and depend on the spatial and temporal configuration of the ice load (Lang et al., 2014). Permanent deformation is restricted to the model layers above the salt structure, which either have a low yield stress to represent the unconsolidated infill of secondary rim-synclines or are dissected by steeply dipping crestal graben faults. Ice-induced salt movements will reactivate faults above the crests of salt structures, although the resulting displacements will be low due to the repeated reversals of the sense of

  17. Load Leveling Battery System Costs

    1994-10-12

    SYSPLAN evaluates capital investment in customer side of the meter load leveling battery systems. Such systems reduce the customer's monthly electrical demand charge by reducing the maximum power load supplied by the utility during the customer's peak demand. System equipment consists of a large array of batteries, a current converter, and balance of plant equipment and facilities required to support the battery and converter system. The system is installed on the customer's side of themore » meter and controlled and operated by the customer. Its economic feasibility depends largely on the customer's load profile. Load shape requirements, utility rate structures, and battery equipment cost and performance data serve as bases for determining whether a load leveling battery system is economically feasible for a particular installation. Life-cycle costs for system hardware include all costs associated with the purchase, installation, and operation of battery, converter, and balance of plant facilities and equipment. The SYSPLAN spreadsheet software is specifically designed to evaluate these costs and the reduced demand charge benefits; it completes a 20 year period life cycle cost analysis based on the battery system description and cost data. A built-in sensitivity analysis routine is also included for key battery cost parameters. The life cycle cost analysis spreadsheet is augmented by a system sizing routine to help users identify load leveling system size requirements for their facilities. The optional XSIZE system sizing spreadsheet which is included can be used to identify a range of battery system sizes that might be economically attractive. XSIZE output consisting of system operating requirements can then be passed by the temporary file SIZE to the main SYSPLAN spreadsheet.« less

  18. The concept of allostasis in biology and biomedicine.

    PubMed

    McEwen, Bruce S; Wingfield, John C

    2003-01-01

    Living organisms have regular patterns and routines that involve obtaining food and carrying out life history stages such as breeding, migrating, molting, and hibernating. The acquisition, utilization, and storage of energy reserves (and other resources) are critical to lifetime reproductive success. There are also responses to predictable changes, e.g., seasonal, and unpredictable challenges, i.e., storms and natural disasters. Social organization in many populations provides advantages through cooperation in providing basic necessities and beneficial social support. But there are disadvantages owing to conflict in social hierarchies and competition for resources. Here we discuss the concept of allostasis, maintaining stability through change, as a fundamental process through which organisms actively adjust to both predictable and unpredictable events. Allostatic load refers to the cumulative cost to the body of allostasis, with allostatic overload being a state in which serious pathophysiology can occur. Using the balance between energy input and expenditure as the basis for applying the concept of allostasis, we propose two types of allostatic overload. Type 1 allostatic overload occurs when energy demand exceeds supply, resulting in activation of the emergency life history stage. This serves to direct the animal away from normal life history stages into a survival mode that decreases allostatic load and regains positive energy balance. The normal life cycle can be resumed when the perturbation passes. Type 2 allostatic overload begins when there is sufficient or even excess energy consumption accompanied by social conflict and other types of social dysfunction. The latter is the case in human society and certain situations affecting animals in captivity. In all cases, secretion of glucocorticosteroids and activity of other mediators of allostasis such as the autonomic nervous system, CNS neurotransmitters, and inflammatory cytokines wax and wane with allostatic

  19. Material behavior under complex loading

    SciTech Connect

    Breuer, H.J.; Raule, G.; Rodig, M.

    1984-09-01

    Studies of material behavior under complex loading form a bridge between standard material testing methods and the stress analysis calculations for reactor components at high temperatures. The aim of these studies is to determine the influence of typical load change sequences on material properties, to derive the equations required for stress analyses, to carry out tests under multiaxial conditions, and to investigate the structural deformation mechanisms of creep buckling and ratcheting. The present state of the investigations within the high-temperature gas-cooled reactor materials program is described, with emphasis on the experimental apparatus, the scope of the program, and the initial results obtained.

  20. Analysis of high load dampers

    NASA Technical Reports Server (NTRS)

    Bhat, S. T.; Buono, D. F.; Hibner, D. H.

    1981-01-01

    High load damping requirements for modern jet engines are discussed. The design of damping systems which could satisfy these requirements is also discusseed. In order to evaluate high load damping requirements, engines in three major classes were studied; large transport engines, small general aviation engines, and military engines. Four damper concepts applicable to these engines were evaluated; multi-ring, cartridge, curved beam, and viscous/friction. The most promising damper concept was selected for each engine and performance was assessed relative to conventional dampers and in light of projected damping requirements for advanced jet engines.

  1. 14 CFR 23.509 - Towing loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... on the landing gear but near the plane of symmetry of the airplane, the drag and side tow load... drag and side tow load components specified for the main gear apply. Where the specified angle of... applied. (2) The towing loads at the auxiliary gear and the drag components of the towing loads at...

  2. 14 CFR 23.509 - Towing loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... on the landing gear but near the plane of symmetry of the airplane, the drag and side tow load... drag and side tow load components specified for the main gear apply. Where the specified angle of... applied. (2) The towing loads at the auxiliary gear and the drag components of the towing loads at...

  3. Spall fracture in additive manufactured Ti-6Al-4V

    DOE PAGES

    Jones, David Robert; Fensin, Saryu Jindal; Dippo, Olivia; Beal, Roberta Ann; Livescu, Verpnica; Martinez, Daniel Tito; Trujillo, Carl Patrick; Florando, J. N.; Kumar, M.; Gray, III, George Thompson

    2016-10-04

    Here, we present a study on the spall strength of additive manufactured (AM) Ti-6Al-4V. Samples were obtained from two pieces of selective laser melted (SLM, a powder bed fusion technique) Ti-6Al-4V such that the response to dynamic tensile loading could be investigated as a function of the orientation between the build layers and the loading direction. A sample of wrought bar-stock Ti-6Al-4V was also tested to act as a baseline representing the traditionally manufactured material response. A single-stage light gas-gun was used to launch a thin flyer plate into the samples, generating a region of intense tensile stress on amore » plane normal to the impact direction. The rear free surface velocity time history of each sample was recorded with laser-based velocimetry to allow the spall strength to be calculated. The samples were also soft recovered to enable post-mortem characterization of the spall damage evolution. Results showed that when the tensile load was applied normal to the interfaces between the build layers caused by the SLM fabrication process the spall strength was drastically reduced, dropping to 60% of that of the wrought material. However, when loaded parallel to the AM build layer interfaces the spall strength was found to remain at 95% of the wrought control, suggesting that when loading normal to the AM layer interfaces, void nucleation is facilitated more readily due to weaknesses along these boundaries. Quasi-static testing of the same sample orientations revealed a much lower degree of anisotropy, demonstrating the importance of rate-dependent studies for damage evolution in AM materials.« less

  4. Spall fracture in additive manufactured Ti-6Al-4V

    NASA Astrophysics Data System (ADS)

    Jones, D. R.; Fensin, S. J.; Dippo, O.; Beal, R. A.; Livescu, V.; Martinez, D. T.; Trujillo, C. P.; Florando, J. N.; Kumar, M.; Gray, G. T.

    2016-10-01

    We present a study on the spall strength of additive manufactured (AM) Ti-6Al-4V. Samples were obtained from two pieces of selective laser melted (SLM, a powder bed fusion technique) Ti-6Al-4V such that the response to dynamic tensile loading could be investigated as a function of the orientation between the build layers and the loading direction. A sample of wrought bar-stock Ti-6Al-4V was also tested to act as a baseline representing the traditionally manufactured material response. A single-stage light gas-gun was used to launch a thin flyer plate into the samples, generating a region of intense tensile stress on a plane normal to the impact direction. The rear free surface velocity time history of each sample was recorded with laser-based velocimetry to allow the spall strength to be calculated. The samples were also soft recovered to enable post-mortem characterization of the spall damage evolution. Results showed that when the tensile load was applied normal to the interfaces between the build layers caused by the SLM fabrication process the spall strength was drastically reduced, dropping to 60% of that of the wrought material. However, when loaded parallel to the AM build layer interfaces the spall strength was found to remain at 95% of the wrought control, suggesting that when loading normal to the AM layer interfaces, void nucleation is facilitated more readily due to weaknesses along these boundaries. Quasi-static testing of the same sample orientations revealed a much lower degree of anisotropy, demonstrating the importance of rate-dependent studies for damage evolution in AM materials.

  5. ALS Performance Summary - Update

    SciTech Connect

    Waters, A M; Brown, W D; Martz, Jr., H E

    2004-09-30

    High Energy Density Physics (HEDP) experiments play an important role in corroborating the improved physics codes that underlie LLNL's Stockpile Stewardship mission. Conducting these experiments, whether on the National Ignition Facility (NIF) or another national facility such as Omega, will require not only improvement in the diagnostics for measuring the experiment, but also detailed knowledge of the as-built target components and assemblies themselves. To assist in this effort, a defined set of well-known reference standards designed to represent a range of HEDP targets have been built and are being used to quantify the performance of different characterization techniques [Hibbard, et al. 2004]. Without the critical step of using reference standards for qualifying characterization tools there can be no verification of either commercial or internally-developed characterization techniques and thus an uncertainty in the input to the physics code models would exist.

  6. Behavior of soil anchors under dynamic loads

    SciTech Connect

    Picornell, M.; Olague, B.

    1997-07-01

    Helical anchors placed in a cohesionless soil in a laboratory setting were tested under static and dynamic loads. The dynamic tests were performed after subjecting the anchors to a seating load. The dynamic load had an intensity that changed in sinusoidal fashion and was superimposed to the static seating loads. Although, the anchors have a static pull-out capacity, when the dynamic loads are applied the anchor experiences additional deformations for each load cycle. The deformations per cycle are initially high but then decrease to a nearly constant rate. Eventually, the constant rate increases suddenly accelerating until failure. This failure can take place even at small fractions of the static pull-out capacity. The rate of deformation per load cycle is found to increase for larger seating loads and for larger dynamic pulsating loads. The results of this study shows that the designer can only adjust loads to decrease the deformation rate to suit the design life of the structure.

  7. Factor reliability into load management

    SciTech Connect

    Feight, G.R.

    1983-07-01

    Hardware reliability is a major factor to consider when selecting a direct-load-control system. The author outlines a method of estimating present-value costs associated with system reliability. He points out that small differences in receiver reliability make a significant difference in owning cost. 4 figures.

  8. Appraisal of formulas for stresses in bilayered dental ceramics subjected to biaxial moment loading

    SciTech Connect

    Hsueh, Chun-Hway; Thompson, G. A.

    2007-01-01

    Summary - Objectives: The purpose of this study was to compare three existing sets of formulas predicting stresses in a thin circular plate subjected to biaxial moment loading, such that limitations for each set of formulas could be understood. These formulas include American Society for Testing and Materials (ASTM) formulas for monolayered plates, Roark's formulas for bilayered plates, and Hsueh et al.'s formulas for multilayered plates. Methods: The three sets of formulas were summarized and appraised. Biaxial moment loading is generally achieved using biaxial flexure tests, and the plate is placed on a support ring and loaded in the central region. While both ASTM and Hsueh et al.'s formulas predict stresses through the thickness of the plate, Roark's formulas predict stresses only on the top and the bottom surfaces of the plate. Also, a simply supported plate at its edge is considered in Roark's formulas. We modified Roark's formulas to include the overhang region of the plate to more closely simulate the actual loading configuration. Then, the accuracy of formulas was examined by comparing with finite element results of monolayered and bilayered plates subjected to ring-on-ring loading. Results: Monolayer is a special case of bilayer, and both monolayer and bilayer are special cases of multilayer. For monolayered plates, ASTM and Hsueh et al.'s formulas are identical, and both are in excellent agreement with finite element results. For bilayered plates, Hsueh et al.'s formulas are in excellent agreement with finite element results. For both monolayered and bilayered plates, Roark's formulas deviate from finite element results while the modified Roark's formulas are accurate. Conclusions: Roark's formulas for evaluating the biaxial strength of bilayered dental ceramics will result in errors in predicted stresses which depend on the size of the overhang region of the plate in the actual loading configuration. Also, Roark's formulas are limited to predicting

  9. Behavior of metals Induced by magnetic pulse loading

    NASA Astrophysics Data System (ADS)

    Svetlana, Atroshenko; Viktor, Morozov; Denis, Gribanov; Anton, Lukin; Yuriy, Petrov

    2015-09-01

    The investigation of copper and aluminum ring samples was carried out using magnetic pulse loading. Two modifications of the magnetic pulse technique were used. They were based on a GKVI-300 high-voltage narrow-pulse generator Morozov et al. (2011) [1]. It is possible using these two approaches to decrease the period of the harmonic load up to 100 ns. The study of fracture surfaces of aluminum and copper samples after the test was carried out on an optical microscope Axio-Observer-Z1-M in a dark field, and study of the cross sections structure - in the bright field or C-DIC. The structure has been studied in cross sections after appropriate etching. Grain size and the number of pores on the surface of cross sections were determined after etching. Microhardness was measured on a PMT-3 device with a load of 20 g. The optical micrographs of aluminum demonstrate that the long pulse causes almost fully ductile fracture. In the case of the short pulse, the number of fibers decreases: the fracture surface exhibits the signs of both ductile cup fracture and brittle crystalline fracture with cracks, which are sometimes rather deep. In addition, the short pulse results in twinning, which seems surprising for aluminum featuring a high stacking fault energy. It is seen that under short loading dynamic recrystallization occurs. As for copper samples before loading they were in the form of single crystal and after loading their structure due to dynamic recrystallization consists of small grain. The specimen with notch has more developed dynamic recrystallization shear bands.

  10. Modeling shear instability and fracture in dynamically deformed Al/W granular composites

    NASA Astrophysics Data System (ADS)

    Olney, Karl; Benson, David; Nesterenko, Vitali F.

    2012-03-01

    Aluminum/Tungsten granular composites are materials which combine high density and strength with bulk distributed fracture of Al matrix into small particles under impact or shock loading. They are processed using cold and hot isostatic pressing of W particles/rods in the matrix of Al powder. Numerical models were used to elucidate the dynamic behavior of these materials under dynamic conditions simulating low velocity high energy impact in drop weight test (10 m/s). It was demonstrated that arrangement of W components and bonding between Al particles dramatically affect the samples shear localization and mode of fracture of the Al matrix in agreement with experiments.

  11. Constitution of pseudobinary hypoeutectic beta-NiAl + alpha-V alloys

    NASA Technical Reports Server (NTRS)

    Cotton, J. D.; Kaufman, M. J.; Noebe, R. D.

    1991-01-01

    The formation of pseudobinary eutectics between NiAl (beta) and V (alpha) at high temperatures was investigated as a possible way of improving the ductility and toughness of the alloy. It is found that a pseudobinary eutectic, characterized by a large beta+alpha field, is formed in the Ni-Al-V ternary system below about 1370 C. The high-temperature solubility of V in beta is about 14 percent, decreasing markedly with decreasing temperature and increasing Al content above 50 at. pct Al. The pseudobinary hypoeutectic exibits crack resistance under indentation loading.

  12. Theoretical studies of AlF, AlCl, and AlBr

    NASA Technical Reports Server (NTRS)

    Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Taylor, Peter R.

    1988-01-01

    Spectroscopic constants have been obtained for the lowest six singlet and lowest five triplet states of AlF and AlCl. The results suggest that the correct ordering of the triplet manifold in these molecules is: a 3Pi, b 3Sigma(+), c 3Sigma(+), d 3Pi, and e 3Delta. Radiative lifetimes have been determined for the excited states, and the A 1Pi to X 1Sigma(+) transition in AlF, AlCl, and AlBr has been examined in detail. A-X transition moment functions, Einstein coefficients, and A 1Pi vibrational lifetimes have been obtained for AlF and AlCl.

  13. Atmospheric pressure loading parameters from very long baseline interferometry observations

    NASA Technical Reports Server (NTRS)

    Macmillan, D. S.; Gipson, John M.

    1994-01-01

    Atmospheric mass loading produces a primarily vertical displacement of the Earth's crust. This displacement is correlated with surface pressure and is large enough to be detected by very long baseline interferometry (VLBI) measurements. Using the measured surface pressure at VLBI stations, we have estimated the atmospheric loading term for each station location directly from VLBI data acquired from 1979 to 1992. Our estimates of the vertical sensitivity to change in pressure range from 0 to -0.6 mm/mbar depending on the station. These estimates agree with inverted barometer model calculations (Manabe et al., 1991; vanDam and Herring, 1994) of the vertical displacement sensitivity computed by convolving actual pressure distributions with loading Green's functions. The pressure sensitivity tends to be smaller for stations near the coast, which is consistent with the inverted barometer hypothesis. Applying this estimated pressure loading correction in standard VLBI geodetic analysis improves the repeatability of estimated lengths of 25 out of 37 baselines that were measured at least 50 times. In a root-sum-square (rss) sense, the improvement generally increases with baseline length at a rate of about 0.3 to 0.6 ppb depending on whether the baseline stations are close to the coast. For the 5998-km baseline from Westford, Massachusetts, to Wettzell, Germany, the rss improvement is about 3.6 mm out of 11.0 mm. The average rss reduction of the vertical scatter for inland stations ranges from 2.7 to 5.4 mm.

  14. Use of Flexible Body Coupled Loads in Assessment of Day of Launch Flight Loads

    NASA Technical Reports Server (NTRS)

    Starr, Brett R.; Yunis, Isam; Olds, Aaron D.

    2011-01-01

    A Day of Launch flight loads assessment technique that determines running loads calculated from flexible body coupled loads was developed for the Ares I-X Flight Test Vehicle. The technique was developed to quantify DOL flight loads in terms of structural load components rather than the typically used q-alpha metric to provide more insight into the DOL loads. In this technique, running loads in the primary structure are determined from the combination of quasi-static aerodynamic loads and dynamic loads. The aerodynamic loads are calculated as a function of time using trajectory parameters passed from the DOL trajectory simulation and are combined with precalculated dynamic loads using a load combination equation. The potential change in aerodynamic load due to wind variability during the countdown is included in the load combination. In the event of a load limit exceedance, the technique allows the identification of what load component is exceeded, a quantification of how much the load limit is exceeded, and where on the vehicle the exceedance occurs. This technique was used to clear the Ares I-X FTV for launch on October 28, 2009. This paper describes the use of coupled loads in the Ares I-X flight loads assessment and summarizes the Ares I-X load assessment results.

  15. 14 CFR 29.511 - Ground load: unsymmetrical loads on multiple-wheel units.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground load: unsymmetrical loads on multiple-wheel units. 29.511 Section 29.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Requirements Ground Loads § 29.511 Ground load: unsymmetrical loads on multiple-wheel units. (a) In...

  16. 14 CFR 23.511 - Ground load; unsymmetrical loads on multiple-wheel units.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground load; unsymmetrical loads on multiple-wheel units. 23.511 Section 23.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Structure Ground Loads § 23.511 Ground load; unsymmetrical loads on multiple-wheel...

  17. 46 CFR 154.1730 - Ethylene oxide: Loading and off loading.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ethylene oxide: Loading and off loading. 154.1730... Operating Requirements § 154.1730 Ethylene oxide: Loading and off loading. (a) The master shall ensure that before ethylene oxide is loaded into a cargo tank: (1) The tank is thoroughly clean, dry, and free...

  18. 46 CFR 154.1730 - Ethylene oxide: Loading and off loading.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ethylene oxide: Loading and off loading. 154.1730... Operating Requirements § 154.1730 Ethylene oxide: Loading and off loading. (a) The master shall ensure that before ethylene oxide is loaded into a cargo tank: (1) The tank is thoroughly clean, dry, and free...

  19. 46 CFR 154.1730 - Ethylene oxide: Loading and off loading.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ethylene oxide: Loading and off loading. 154.1730... Operating Requirements § 154.1730 Ethylene oxide: Loading and off loading. (a) The master shall ensure that before ethylene oxide is loaded into a cargo tank: (1) The tank is thoroughly clean, dry, and free...

  20. The Microstructure-Processing-Property Relationships in an Al Matrix Composite System Reinforced by Al-Cu-Fe Alloy Particles

    SciTech Connect

    Tang, Fei

    2004-01-01

    the matrix choice (elemental Al) and the ''low shear'' consolidation methods utilized. This reinforcement effectiveness is further evidenced by elastic modulus measurements of the composites that are very close to the upper bound predictions of the rule of mixtures. The load partitioning measurements by neutron diffraction showed that composite samples made from GARS powders present significantly higher load transfer efficiency than the composites made from commercially atomized powders. Also, the composite samples made from GARS powders show a higher strengthening effect and ductility than the samples made from commercial purity powders. The higher load transfer efficiency and higher strength and ductility may result from an enhanced inter-particle bonding strength, promoted by the ''clean'' interfaces between particles. Further analysis of the load sharing measurements and the calculated values of the mismatch of coefficient of thermal expansion (CTE) and the geometrically necessary dislocation (GND) effects suggest that these strengthening mechanisms can be combined to predict accurately the strength of the composites.

  1. Minimal adhesion surface area in tangentially loaded digital contacts.

    PubMed

    Terekhov, Alexander V; Hayward, Vincent

    2011-09-01

    The stick-to-slip transition of a fingertip in contact with a planar surface does not occur instantaneously. As the tangential load increases, portions of the skin adhere while others slip, giving rise to an evolution of the contact state, termed partial slip. We develop a quasi-static model that predicts that if the coefficient of kinetic friction is larger than the coefficient of static friction, then the stuck surface area diminishes as the tangential load increases until reaching a 'minimal adhesion surface area' where it vanishes abruptly. This phenomenon was observed in recently measured finger-slip image data (André et al., 2011) that were processed by an optic flow detection algorithm. We examined the results of 10 trials. Four of them exhibited the minimal adhesion surface area phenomenon, four of them did not, and two were inconclusive.

  2. Minimal adhesion surface area in tangentially loaded digital contacts.

    PubMed

    Terekhov, Alexander V; Hayward, Vincent

    2011-09-01

    The stick-to-slip transition of a fingertip in contact with a planar surface does not occur instantaneously. As the tangential load increases, portions of the skin adhere while others slip, giving rise to an evolution of the contact state, termed partial slip. We develop a quasi-static model that predicts that if the coefficient of kinetic friction is larger than the coefficient of static friction, then the stuck surface area diminishes as the tangential load increases until reaching a 'minimal adhesion surface area' where it vanishes abruptly. This phenomenon was observed in recently measured finger-slip image data (André et al., 2011) that were processed by an optic flow detection algorithm. We examined the results of 10 trials. Four of them exhibited the minimal adhesion surface area phenomenon, four of them did not, and two were inconclusive. PMID:21774936

  3. Fretting Wear of Ti-48Al-2Cr-2Nb

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Lerch, Bradley A.; Draper, Susan L.

    2001-01-01

    An investigation was conducted to examine the wear behavior of gamma titanium aluminide (Ti-48Al-2Cr-2Nb in atomic percent) in contact with a typical nickel-base superalloy under repeated microscopic vibratory motion in air at temperatures from 296-823 K. The surface damage observed on the interacting surfaces of both Ti-48Al-2Cr-2Nb and superalloy consisted of fracture pits, oxides, metallic debris, scratches, craters, plastic deformation, and cracks. The Ti-48Al-2Cr-2Nb transferred to the superalloy at all fretting conditions and caused scuffing or galling. The increasing rate of oxidation at elevated temperatures led to a drop in Ti-48Al-2Cr-2Nb wear at 473 K. Mild oxidative wear was observed at 473 K. However, fretting wear increased as the temperature was increased from 473-823 K. At 723 and 823 K, oxide disruption generated cracks, loose wear debris, and pits on the Ti-48Al-2Cr-2Nb wear surface. Ti-48Al-2Cr-2Nb wear generally decreased with increasing fretting frequency. Both increasing slip amplitude and increasing load tended to produce more metallic wear debris, causing severe abrasive wear in the contacting metals. Keywords

  4. Spinning Reserve From Responsive Loads

    SciTech Connect

    Kirby, B.J.

    2003-04-08

    Responsive load is the most underutilized reliability resource available to the power system today. It is currently not used at all to provide spinning reserve. Historically there were good reasons for this, but recent technological advances in communications and controls have provided new capabilities and eliminated many of the old obstacles. North American Electric Reliability Council (NERC), Federal Energy Regulatory Commission (FERC), Northeast Power Coordinating Council (NPCC), New York State Reliability Council (NYSRC), and New York Independent System Operator (NYISO) rules are beginning to recognize these changes and are starting to encourage responsive load provision of reliability services. The Carrier ComfortChoice responsive thermostats provide an example of these technological advances. This is a technology aimed at reducing summer peak demand through central control of residential and small commercial air-conditioning loads. It is being utilized by Long Island Power Authority (LIPA), Consolidated Edison (ConEd), Southern California Edison (SCE), and San Diego Gas and Electric (SDG&E). The technology is capable of delivering even greater response in the faster spinning reserve time frame (while still providing peak reduction). Analysis of demand reduction testing results from LIPA during the summer of 2002 provides evidence to back up this claim. It also demonstrates that loads are different from generators and that the conventional wisdom, which advocates for starting with large loads as better ancillary service providers, is flawed. The tempting approach of incrementally adapting ancillary service requirements, which were established when generators were the only available resources, will not work. While it is easier for most generators to provide replacement power and non-spinning reserve (the slower response services) than it is to supply spinning reserve (the fastest service), the opposite is true for many loads. Also, there is more financial

  5. Marine loading vapor control systems

    SciTech Connect

    Babet, F.H.

    1996-09-01

    The EPA and State air quality control boards have mandated the collection and destruction or recovery of vapors generated by the loading of some hydrocarbons and chemicals into marine vessels. This is a brief overview of the main US Coast Guard requirements for marine vapor control systems. As with most regulations, they are open to interpretation. In an attempt to more clearly define the intent of the regulations, the US Coast Guard has issued guidelines to assist the certifying entities in ensuring compliance with intended regulations. If a company is contemplating the installation of a marine loading vapor control system, the authors strongly recommend that one engage the services of a certifying entity, either as the designer, or an advisor and ultimately the certifier of the system. This should be done well up front in the design of the system to avoid costly mistakes which can occur as a result of lack of knowledge or misinterpretation of the regulations and guidelines.

  6. Thermal loading of natural streams

    USGS Publications Warehouse

    Jackman, Alan P.; Yotsukura, Nobuhiro

    1977-01-01

    The impact of thermal loading on the temperature regime of natural streams is investigated by mathematical models, which describe both transport (convection-diffusion) and decay (surface dissipation) of waste heat over 1-hour or shorter time intervals. The models are derived from the principle of conservation of thermal energy for application to one- and two-dimensional spaces. The basic concept in these models is to separate water temperature into two parts, (1) excess temperature due to thermal loading and (2) natural (ambient) temperature. This separation allows excess temperature to be calculated from the models without incoming radiation data. Natural temperature may either be measured in prototypes or calculated from the model. If use is made of the model, however, incoming radiation is required as input data. Comparison of observed and calculated temperatures in seven natural streams shows that the models are capable of predicting transient temperature regimes satisfactorily in most cases. (Woodard-USGS)

  7. Understanding HIV-1 viral load.

    PubMed

    Paxton, W B

    1995-01-01

    HIV viral markers, such as p24 antigen and viral RNA, measure how much virus is present. Studies are showing a relationship between RNA levels and clinical outcomes, which can help doctors evaluate the efficacy of drug therapy. Eventually, it is believed, RNA will replace T-cell counts as the marker of choice. The challenge is to interpret what the results of a viral load test mean for a specific patient. Currently, the two main viral load tests commercially available do not have a one-to-one linear relationship, so tests should not be switched. Doctors are advised not to over-interpret minor changes because of the ten to thirty percent variation in individual test results. These tests are not FDA-approved but are available at commercial reference labs. PMID:11362660

  8. 39. VIEW OF CHRYSLER WORKERS LOADING A SATURN IB BOOSTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. VIEW OF CHRYSLER WORKERS LOADING A SATURN IB BOOSTER INTO THE EAST POSITION ON THE STATIC TEST TOWER. AS THE MAIN CONTRACTOR OF THE SATURN IB BOOSTER, CHRYSLER TOOK OVER OPERATIONS OF THE EAST POSITION OF THE STATIC TEST TOWER IN 1963. THAT SAME YEAR, THE WEST POSITION OF THE TEST TOWER WAS MODIFIED (AS SEEN IN THE PHOTO) FOR RESEARCH AND DEVELOPMENT TESTS OF THE SATURN V BOOSTER'S ENGINE, THE F-1. MARCH 1963, MSFC PHOTO LAB. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

  9. Passive detection of vehicle loading

    NASA Astrophysics Data System (ADS)

    McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Salvaggio, Philip S.; McKeown, Donald M.; Garrett, Alfred J.; Coleman, David H.; Koffman, Larry D.

    2012-01-01

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  10. Control Allocation with Load Balancing

    NASA Technical Reports Server (NTRS)

    Bodson, Marc; Frost, Susan A.

    2009-01-01

    Next generation aircraft with a large number of actuators will require advanced control allocation methods to compute the actuator commands needed to follow desired trajectories while respecting system constraints. Previously, algorithms were proposed to minimize the l1 or l2 norms of the tracking error and of the actuator deflections. The paper discusses the alternative choice of the l(infinity) norm, or sup norm. Minimization of the control effort translates into the minimization of the maximum actuator deflection (min-max optimization). The paper shows how the problem can be solved effectively by converting it into a linear program and solving it using a simplex algorithm. Properties of the algorithm are also investigated through examples. In particular, the min-max criterion results in a type of load balancing, where the load is th desired command and the algorithm balances this load among various actuators. The solution using the l(infinity) norm also results in better robustness to failures and to lower sensitivity to nonlinearities in illustrative examples.

  11. PASSIVE DETECTION OF VEHICLE LOADING

    SciTech Connect

    Garrett, A.

    2012-01-03

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  12. Alexandria (Al Iskandariya), Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

  13. Explosive Fabrication of Intermetallics In Ti-Al System from Nano-Al and Coarse-Ti Powders

    NASA Astrophysics Data System (ADS)

    Chikhradze, Mikheil; Gigineishvili, Akaki; Cikhradze, Nikoloz

    2011-12-01

    Theoretical and experimental Investigations of shock wave consolidation processes of Ti-Al nano sized and ultra-disperse powder compositions are discussed. For theoretical calculations of the shock wave loaded materials were used the hydrodynamic theory and experimental adiabatics of Ti and Al. The normal and tangential stresses in the cylindrical steel tube (containers of Ti-Al reaction mixtures) were estimated using the partial solutions of elasticity theory. The mixtures of ultra-disperse Ti and nano sized (max≤50 nm) Al powder compositions were consolidated to full or near-full density by explosive-compaction technology. The ammonium nitride based industrial explosives were used for generation of shock waves. To form ultra-fine grained bulk TiAl intermetallides with different compositions, ultra-disperse Ti particles were mixed with nano-crystalline Al. Each reaction mixture was placed in a sealed container and explosively compacted using a normal and cylindrical detonation set-up. Explosive compaction experiments were performed in range of pressure impulse (5-20 GPA) at elevated temperatures. X-ray diffraction (XRD), structural investigations (SEM) and micro-hardness measurements were used to characterize the intermetallides phase composition and mechanical properties. The results of analysis revealing the effects of the compacting conditions and precursor particles sizes, affecting the consolidation and the properties of this new ultra high performance alloys are discussed.

  14. Impact Mediated Loading Cytoplasmic Loading of Macromolecules into Adherent Cells

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F.; Feeback, Daniel L.; Vanderburg, Charles R.

    2003-01-01

    The advent of modern molecular biology, including the development of gene array technologies, has resulted in an explosion of information concerning the specific genes activated during normal cellular development, as well as those associated with a variety of pathological conditions. These techniques have served as a highly efficient, broacI.-based screening approach for those specific genes involved. in regulating normal cellular physiology and identifying candidate genes directly associated with the etiology of specific disease states. However, this approach provides information at the transcriptional' level only and does not necessarily indicate . that the gene in question is in fact translated ito a protein, or whether or not post-translational modification of the protein occurs. The critical importance of post-translational modification (i.e. phosphorylation, glycosylation, sialyation, etc.) to protein function has been recognized with regard to a number of proteins involved in a variety of important disease states. For example, altered glycosylation of beta-amyloid precursor protein results in an increase in the amount of beta-amyloid peptide generated and hence secreted as insoluble extracellular amyloid deposits (Georgopoulou, McLaughlin et al. 2001; Walter, Fluhrer et al. 2001), a pathological hal1nark of Alzheimer's disease. Abnormal phosphorylaion of synapsin I has been linked to alterations in synaptic vesicle trafficking leading to defective neurotransmission in Huntington's disease (Lievens, Woodman et al. 2002). Altered phosphorylation of the TAU protein involved in microtubule function has been linked to a number of neurodegenative diseases such as Alzheimer's disease (Billingsley and Kincaid 1997; Sanchez, Alvarez-Tllada et a1. 2001). Aberrant siaIyation of cell/I surface antigens has been detected in a number of different tumor cell types and has been linked to the acquisition of a neoplastic phenotype (Sell 1990), while improper' sia1yation of

  15. Fatigue crack growth in damage tolerant Al-Li sheet alloys

    NASA Astrophysics Data System (ADS)

    Wanhill, R. J. H.

    1990-03-01

    The fatigue crack growth properties of two candidate damage tolerant Al-Li sheet alloys, 2091 and 8090 are compared with those of the conventional and widely used 2024 alloy. There were three load histories: constant amplitude, gust spectrum, and constant amplitude with occasional peak loads. The results are interpreted with the aid of fractographic observations and measurements of fracture surface roughness. The practical significance of the results is assessed, and recommendations are made for further evaluations.

  16. RELATIONSHIPS BETWEEEN NITROGEN LOADING AND CONCENTRATIONS OF NITROGEN AND CHLOROPHYLL IN COASTAL EMBAYMENTS

    EPA Science Inventory

    We describe results obtained with a simple model that uses loading rates of total nitrogen (TN), defined as dissolved inorganic nitrogen plus dissolved and particulate organic nitrogen, to calculate annually and spatially averaged concentrations of TN in coastal embayments. We al...

  17. The concept of target and critical loads

    SciTech Connect

    Grigal, D.F.

    1991-09-01

    Target and critical loads were initially developed for assessment and control of acidic deposition, but are being considered for other air pollutants such as ozone and air-borne toxic compounds. These loads are based on thresholds, with damage assumed to occur above some defined level of deposition. Many of the historically proposed targets for acidic deposition were based on arbitrary interpretations of data. The concept of critical loads has recently separated from that of target loads. A critical load is the amount of pollutant deposition, determined by technical analysis, above which there is a specific deleterious ecological effect. A target load is the deposition, determined by political agreement, above which unacceptable ecological damage occurs; it may be greater than the critical load because of political or economic considerations, or less to conservatively account for uncertainty in the estimation of the critical load. Recent definitions of critical loads include recognition that each kind of ecosystem and effect may require a different load. Geographic regions contain a mosaic of aquatic and terrestrial resources. If precise knowledge leads to different critical loads for each system, then how is the regional target load established For better or worse, target and critical loads are likely to be used to regulate air pollutants. The philosophy of their establishment as thresholds, their quantitative validity, and their application in regulation all require careful examination. 36 refs., 3 figs.

  18. Comparison of AlCrN and AlCrTiSiN coatings deposited on the surface of plasma nitrocarburized high carbon steels

    NASA Astrophysics Data System (ADS)

    Chen, Wanglin; Zheng, Jie; Lin, Yue; Kwon, Sikchol; Zhang, Shihong

    2015-03-01

    The AlCrN and AlCrTiSiN coatings were produced on the surface of plasma nitrocarburized T10 steels by multi-arc ion plating. The comparison of the microstructures and mechanical properties of the duplex coatings were investigated by means of X-ray diffraction, optical microscope, scanning electron microscope and transmission electron microscope, in association with mechanical property measurement. The results show that the AlCrN coatings with columnar grown are mainly composed of nanocrytalline fcc-(Cr,Al)N phases with {111} preferred orientation, whereas the superlattice and nanocomposite AlCrTiSiN coatings with planar growth mainly consist of nanocrystalline fcc-(Cr,Al)N phases with {100} perfected orientation, hcp-AlN and Si3N4 amorphous phases. The AlCrTiSiN duplex coating with the compound layer reveals higher hardness, adhesion strength, load capacity and lower friction coefficient when compared with the other duplex coatings, which is due to its superlattice and nanocomposite structure. Additionally, these improved properties are related to the appearance of the γ‧-phase which plays the nucleation sites for the coating nitrides and provides a strong supporting effect for the AlCrN and AlCrTiSiN coatings. The main wear mechanism of the duplex coatings without compound layer is spalling and chipping wear as well as tribooxidation wear, whereas the main wear mechanism of the duplex coatings with compound layer is tribooxidation wear.

  19. Thermal Modeling of Al-Al and Al-Steel Friction Stir Spot Welding

    NASA Astrophysics Data System (ADS)

    Jedrasiak, P.; Shercliff, H. R.; Reilly, A.; McShane, G. J.; Chen, Y. C.; Wang, L.; Robson, J.; Prangnell, P.

    2016-07-01

    This paper presents a finite element thermal model for similar and dissimilar alloy friction stir spot welding (FSSW). The model is calibrated and validated using instrumented lap joints in Al-Al and Al-Fe automotive sheet alloys. The model successfully predicts the thermal histories for a range of process conditions. The resulting temperature histories are used to predict the growth of intermetallic phases at the interface in Al-Fe welds. Temperature predictions were used to study the evolution of hardness of a precipitation-hardened aluminum alloy during post-weld aging after FSSW.

  20. Thermal Modeling of Al-Al and Al-Steel Friction Stir Spot Welding

    NASA Astrophysics Data System (ADS)

    Jedrasiak, P.; Shercliff, H. R.; Reilly, A.; McShane, G. J.; Chen, Y. C.; Wang, L.; Robson, J.; Prangnell, P.

    2016-09-01

    This paper presents a finite element thermal model for similar and dissimilar alloy friction stir spot welding (FSSW). The model is calibrated and validated using instrumented lap joints in Al-Al and Al-Fe automotive sheet alloys. The model successfully predicts the thermal histories for a range of process conditions. The resulting temperature histories are used to predict the growth of intermetallic phases at the interface in Al-Fe welds. Temperature predictions were used to study the evolution of hardness of a precipitation-hardened aluminum alloy during post-weld aging after FSSW.

  1. Philosophieren als Unterrichtsprinzip im Mathematikunterricht

    NASA Astrophysics Data System (ADS)

    Meerwaldt, Diana

    Philosophieren und Mathematik scheinen zunächst gegensätzliche Bereiche zu sein, die sich kaum vereinbaren lassen. Dies trifft für eine Auffassung zu, die Philosophieren als "Gerede" disqualifiziert und Mathematik als eine reine "Formelwissenschaft" begreift. Beide Auffassungen werden den Gegenständen nicht gerecht.

  2. 30 CFR 56.6600 - Loading practices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Electricity § 56.6600 Loading practices. If extraneous electricity is suspected in an area where electric... levels of extraneous electricity are found, the source shall be determined and no loading shall...

  3. 30 CFR 56.6600 - Loading practices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Electricity § 56.6600 Loading practices. If extraneous electricity is suspected in an area where electric... levels of extraneous electricity are found, the source shall be determined and no loading shall...

  4. 30 CFR 56.6600 - Loading practices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Electricity § 56.6600 Loading practices. If extraneous electricity is suspected in an area where electric... levels of extraneous electricity are found, the source shall be determined and no loading shall...

  5. 30 CFR 56.6600 - Loading practices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Electricity § 56.6600 Loading practices. If extraneous electricity is suspected in an area where electric... levels of extraneous electricity are found, the source shall be determined and no loading shall...

  6. 30 CFR 75.1318 - Loading boreholes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) When loading boreholes drilled at an angle of 45 degrees or greater from the horizontal in solid rock or loading long holes drilled upward in anthracite mines— (1) The first cartridge in each...

  7. 1994 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1994-12-01

    The 1994 Pacific Northwest Loads and Resources Study presented herein establishes a picture of how the agency is positioned today in its loads and resources balance. It is a snapshot of expected resource operation, contractual obligations, and rights. This study does not attempt to present or analyze future conservation or generation resource scenarios. What it does provide are base case assumptions from which scenarios encompassing a wide range of uncertainties about BPA`s future may be evaluated. The Loads and Resources Study is presented in two documents: (1) this summary of Federal system and Pacific Northwest region loads and resources and (2) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. This analysis updates the 1993 Pacific Northwest Loads and Resources Study, published in December 1993. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The Federal system and regional analyses for medium load forecast are presented.

  8. METHODS OF ANALYSIS FOR WASTE LOAD ALLOCATION

    EPA Science Inventory

    This research has addressed several unresolved questions concerning the allocation of allowable waste loads among multiple wastewater dischargers within a water quality limited stream segment. First, the traditional assumptions about critical design conditions for waste load allo...

  9. Acid loading test (pH)

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the ...

  10. ESTIMATING URBAN WET-WEATHER POLLUTANT LOADING

    EPA Science Inventory

    This paper presents procedures for estimating pollutant loads in urban watersheds emanating from wet-weather flow discharge. Equations for pollutant loading estimates will focus on the effects of wastewater characteristics, sewer flow carrying velocity, and sewer-solids depositi...

  11. Adhesion strength of sputtered TiAlN-coated WC insert tool

    NASA Astrophysics Data System (ADS)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2013-09-01

    The adhesion strength of TiAlN coating that deposited by using DC magnetron sputtering on WC insert tool are studied. TiAlN coating are deposited on Tungsten Carbide (WC) insert tool by varying negatively substrate bias from 79 to 221 volt and nitrogen flow rate from 30 to 72 sccm. The adhesion strength are obtained by using Rockwell indentation test method with a Brale diamond at applied load of 60,100 and 150 kgf. The lateral diameter of indentation is plotted on three different applied loads and the adhesion strength of TiAlN coating was obtained from the curved slopes at 100 and 150 kgf. The lower curve slop indicated better adhesion strength. The results shows that the adhesion strength of sputterred TiAlN coating tend to increase as the negatively substrate bias and nitrogen flow rate are increased.

  12. Adhesion strength of sputtered TiAlN-coated WC insert tool

    SciTech Connect

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2013-09-09

    The adhesion strength of TiAlN coating that deposited by using DC magnetron sputtering on WC insert tool are studied. TiAlN coating are deposited on Tungsten Carbide (WC) insert tool by varying negatively substrate bias from 79 to 221 volt and nitrogen flow rate from 30 to 72 sccm. The adhesion strength are obtained by using Rockwell indentation test method with a Brale diamond at applied load of 60,100 and 150 kgf. The lateral diameter of indentation is plotted on three different applied loads and the adhesion strength of TiAlN coating was obtained from the curved slopes at 100 and 150 kgf. The lower curve slop indicated better adhesion strength. The results shows that the adhesion strength of sputterred TiAlN coating tend to increase as the negatively substrate bias and nitrogen flow rate are increased.

  13. The Advanced Launch System (ALS)

    NASA Astrophysics Data System (ADS)

    Eldred, Charles H.

    The Advanced Launch System (ALS) is an unmanned vehicle that will achieve low hardware cost by using a reusable booster stage which flies back to the launch site, and a core stage in which the rocket engines and redundant avionics are in a module that is returned to earth and recovered for reuse. The booster's utilization of liquid propellant instead of solid propellant will help lower the consumable costs. The ALS also includes launch processing and flight control facilities, necessary support equipment, and ground- and flight-operations infrastructure. The ALS program studies show that, through the ALS, the United States can launch a major Mars initiative economically and with confidence. It is estimated that the objective ALS can be operational in the late 1990s.

  14. Nutrient load estimates for Manila Bay, Philippines using population data

    NASA Astrophysics Data System (ADS)

    Sotto, Lara Patricia A.; Beusen, Arthur H. W.; Villanoy, Cesar L.; Bouwman, Lex F.; Jacinto, Gil S.

    2015-06-01

    A major source of nutrient load to periodically hypoxic Manila Bay is the urban nutrient waste water flow from humans and industries to surface water. In Manila alone, the population density is as high as 19,137 people/km2. A model based on a global point source model by Morée et al. (2013) was used to estimate the contribution of the population to nitrogen and phosphorus emissions which was then used in a water transport model to estimate the nitrogen (N) and phosphorus (P) loads to Manila Bay. Seven scenarios for 2050 were tested, with varying degrees and amounts for extent of sewage treatment, and population growth rates were also included. In scenario 1, the sewage connection and treatment remains the same as 2010; in scenario 2, sewage connection is improved but the treatment is the same; in scenario 3, the sewage connection as well as treatment is improved (70% tertiary); and in scenario 4, a more realistic situation of 70% primary treatment achieved with 100% connection to pipes is tested. Scenarios 5, 6, and 7 have the same parameters as 1, 2, and 3 respectively, but with the population growth rate per province reduced to half of what was used in 1, 2, and 3. In all scenarios, a significant increase in N and P loads was observed (varying from 27% to 469% relative to 2010 values). This was found even in scenario 3 where 70% of the waste water undergoes tertiary treatment which removes 80% N and 90% P. However, the lowest increase in N and P load into the bay was achieved in scenarios 5 to 7 where population growth rate is reduced to half of 2010 values. The results suggest that aside from improving sewage treatment, the continued increase of the human population in Manila at current growth rates will be an important determinant of N and P load into Manila Bay.

  15. Control load envelope shaping by live twist

    NASA Technical Reports Server (NTRS)

    Tarzanin, F. J., Jr.; Mirick, P. H.

    1974-01-01

    Rotor control systems experience a rapid load growth resulting from retreating blade stall during flight conditions of high blade loading or airspeeds. An investigation was undertaken to determine the effect of changing blade torsional properties over the rotor flight envelope. The results of this study show that reducing the blade stiffness to introduce more blade live twist significantly reduces the large retreating blade control loads, while expanding the flight envelope and reducing retreating blade stall loads.

  16. Spinning reserve from hotel load response

    SciTech Connect

    Kirby, Brendan; Kueck, John; Laughner, Theo; Morris, Keith

    2008-12-15

    Even though preliminary tests were not conducted during times of highest system or hotel loading during the summer, they showed that hotel load can be curtailed by 22 to 37 percent depending on the outdoor temperature and time of day. Full response occurred in 12 to 60 seconds from when the system operator's command to shed load was issued and the load drop was very rapid. (author)

  17. Plug Load Behavioral Change Demonstration Project

    SciTech Connect

    Metzger, I.; Kandt, A.; VanGeet, O.

    2011-08-01

    This report documents the methods and results of a plug load study of the Environmental Protection Agency's Region 8 Headquarters in Denver, Colorado, conducted by the National Renewable Energy Laboratory. The study quantified the effect of mechanical and behavioral change approaches on plug load energy reduction and identified effective ways to reduce plug load energy. Load reduction approaches included automated energy management systems and behavioral change strategies.

  18. 14 CFR 27.427 - Unsymmetrical loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... unsymmetrical loads arising from yawing and rotor wake effects in combination with the prescribed flight... data, both of the following must be met: (1) One hundred percent of the maximum loading from the symmetrical flight conditions acts on the surface on one side of the plane of symmetry, and no loading acts...

  19. 14 CFR 29.427 - Unsymmetrical loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... unsymmetrical loads arising from yawing and rotor wake effects in combination with the prescribed flight... data, both of the following must be met: (1) One hundred percent of the maximum loading from the symmetrical flight conditions acts on the surface on one side of the plane of symmetry, and no loading acts...

  20. 14 CFR 27.427 - Unsymmetrical loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... unsymmetrical loads arising from yawing and rotor wake effects in combination with the prescribed flight... data, both of the following must be met: (1) One hundred percent of the maximum loading from the symmetrical flight conditions acts on the surface on one side of the plane of symmetry, and no loading acts...

  1. 14 CFR 29.427 - Unsymmetrical loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... unsymmetrical loads arising from yawing and rotor wake effects in combination with the prescribed flight... data, both of the following must be met: (1) One hundred percent of the maximum loading from the symmetrical flight conditions acts on the surface on one side of the plane of symmetry, and no loading acts...

  2. Baby Carriage: Infants Walking with Loads

    ERIC Educational Resources Information Center

    Garciaguirre, Jessie S.; Adolph, Karen E.; Shrout, Patrick E.

    2007-01-01

    Maintaining balance is a central problem for new walkers. To examine how infants cope with the additional balance control problems induced by load carriage, 14-month-olds were loaded with 15% of their body weight in shoulder-packs. Both symmetrical and asymmetrical loads disrupted alternating gait patterns and caused less mature footfall patterns.…

  3. 46 CFR 114.122 - Load lines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Load lines. 114.122 Section 114.122 Shipping COAST GUARD... OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS GENERAL PROVISIONS § 114.122 Load lines. A vessel of 24... line assignment, certification, and marking in subchapter E (Load Lines) of this chapter....

  4. 46 CFR 175.122 - Load lines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Load lines. 175.122 Section 175.122 Shipping COAST GUARD... § 175.122 Load lines. A vessel of 24 meters (79 feet) in length or more, the keel of which was laid or... than a domestic voyage is subject to load line assignment, certification, and marking under suchapter...

  5. 46 CFR 175.122 - Load lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Load lines. 175.122 Section 175.122 Shipping COAST GUARD... § 175.122 Load lines. A vessel of 24 meters (79 feet) in length or more, the keel of which was laid or... than a domestic voyage is subject to load line assignment, certification, and marking under suchapter...

  6. 46 CFR 114.122 - Load lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Load lines. 114.122 Section 114.122 Shipping COAST GUARD... OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS GENERAL PROVISIONS § 114.122 Load lines. A vessel of 24... line assignment, certification, and marking in subchapter E (Load Lines) of this chapter....

  7. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier...

  8. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier...

  9. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and...

  10. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and...

  11. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and...

  12. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier...

  13. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and...

  14. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier...

  15. 14 CFR 296.4 - Joint loading.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Joint loading. 296.4 Section 296.4... REGULATIONS INDIRECT AIR TRANSPORTATION OF PROPERTY General § 296.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and their delivery to a direct air carrier...

  16. 14 CFR 297.4 - Joint loading.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Joint loading. 297.4 Section 297.4... REGULATIONS FOREIGN AIR FREIGHT FORWARDERS AND FOREIGN COOPERATIVE SHIPPERS ASSOCIATIONS General § 297.4 Joint loading. Nothing in this part shall preclude joint loading, meaning the pooling of shipments and...

  17. 49 CFR 238.417 - Side loads.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Side loads. 238.417 Section 238.417 Transportation... load of 80,000 pounds of force applied to the side sill and 10,000 pounds of force applied to the belt rail (horizontal members at the bottom of the window opening in the side frame). (b) These loads...

  18. Neuroimaging of Cognitive Load in Instructional Multimedia

    ERIC Educational Resources Information Center

    Whelan, Robert R.

    2007-01-01

    This paper reviews research literature on cognitive load measurement in learning and neuroimaging, and describes a mapping between the main elements of cognitive load theory and findings in functional neuroanatomy. It is argued that these findings may lead to the improved measurement of cognitive load using neuroimaging. The paper describes how…

  19. 33 CFR 154.510 - Loading arms.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... information. (c) Each mechanical loading arm used for transferring oil or hazardous material must have a means... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Loading arms. 154.510 Section 154... FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Equipment Requirements § 154.510 Loading arms....

  20. 33 CFR 154.510 - Loading arms.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... information. (c) Each mechanical loading arm used for transferring oil or hazardous material must have a means... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Loading arms. 154.510 Section 154... FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Equipment Requirements § 154.510 Loading arms....

  1. 33 CFR 154.510 - Loading arms.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information. (c) Each mechanical loading arm used for transferring oil or hazardous material must have a means... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Loading arms. 154.510 Section 154... FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Equipment Requirements § 154.510 Loading arms....

  2. 33 CFR 154.510 - Loading arms.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information. (c) Each mechanical loading arm used for transferring oil or hazardous material must have a means... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Loading arms. 154.510 Section 154... FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Equipment Requirements § 154.510 Loading arms....

  3. 33 CFR 154.510 - Loading arms.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... information. (c) Each mechanical loading arm used for transferring oil or hazardous material must have a means... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Loading arms. 154.510 Section 154... FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Equipment Requirements § 154.510 Loading arms....

  4. 14 CFR 25.509 - Towing loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... plane of symmetry of the airplane, the drag and side tow load components specified for the auxiliary gear apply. For towing points located outboard of the main gear, the drag and side tow load components... auxiliary gear and the drag components of the towing loads at the main gear must be reacted as follows:...

  5. 14 CFR 25.509 - Towing loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... plane of symmetry of the airplane, the drag and side tow load components specified for the auxiliary gear apply. For towing points located outboard of the main gear, the drag and side tow load components... auxiliary gear and the drag components of the towing loads at the main gear must be reacted as follows:...

  6. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and the...-down pitching conditions is the sum of the balancing loads at V and the specified value of the normal... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maneuvering loads. 23.423 Section...

  7. 14 CFR 23.427 - Unsymmetrical loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Balancing Surfaces § 23.427 Unsymmetrical loads. (a) Horizontal surfaces other than main wing and their supporting structure must be designed for unsymmetrical loads arising from yawing and slipstream effects, in... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Unsymmetrical loads. 23.427 Section...

  8. 14 CFR 23.427 - Unsymmetrical loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Balancing Surfaces § 23.427 Unsymmetrical loads. (a) Horizontal surfaces other than main wing and their supporting structure must be designed for unsymmetrical loads arising from yawing and slipstream effects, in... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Unsymmetrical loads. 23.427 Section...

  9. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and the...-down pitching conditions is the sum of the balancing loads at V and the specified value of the normal... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maneuvering loads. 23.423 Section...

  10. Plutonium Immobilization Can Loading Preliminary Specifications

    SciTech Connect

    Kriikku, E.

    1998-11-25

    This report discusses the Plutonium Immobilization can loading preliminary equipment specifications and includes a process block diagram, process description, equipment list, preliminary equipment specifications, plan and elevation sketches, and some commercial catalogs. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.

  11. Properly Evaluating load-following products

    SciTech Connect

    Cavicchi, Joseph; Lemon, Andrew

    2009-01-15

    The authors briefly survey the jurisdictions where load-following products have been successfully used, examine the characteristics of the load-following products, and explain the shortcomings and inaccurate conclusions of previous analyses. A more thorough analysis reveals that the load-following products fulfill the public policy objectives for which they have been designed and do not adversely impact wholesale electricity markets.

  12. Structural dynamics payload loads estimates

    NASA Technical Reports Server (NTRS)

    Engels, R. C.

    1980-01-01

    Present analytical techniques by which design loads are predicted are very costly and time consuming. Chapter I presents the standard techniques used to analyze payload/booster systems. They are full scale methods in the sense that they all require the solution of the coupled equations of motion of the payload/booster system. Chapter II identifies several short cut methodologies. These already existing techniques do not require the solution of the coupled system equations. The potentials and shortcomings of each of these methods are discussed. Chapter III covers the favored methods accompanied by recommendations for further development, refinement, and demonstrations. An outline of a new approach is also included.

  13. Automated fuel pin loading system

    DOEpatents

    Christiansen, David W.; Brown, William F.; Steffen, Jim M.

    1985-01-01

    An automated loading system for nuclear reactor fuel elements utilizes a gravity feed conveyor which permits individual fuel pins to roll along a constrained path perpendicular to their respective lengths. The individual lengths of fuel cladding are directed onto movable transports, where they are aligned coaxially with the axes of associated handling equipment at appropriate production stations. Each fuel pin can be reciprocated axially and/or rotated about its axis as required during handling steps. The fuel pins are inserted as a batch prior to welding of end caps by one of two disclosed welding systems.

  14. High loading uranium fuel plate

    DOEpatents

    Wiencek, Thomas C.; Domagala, Robert F.; Thresh, Henry R.

    1990-01-01

    Two embodiments of a high uranium fuel plate are disclosed which contain a meat comprising structured uranium compound confined between a pair of diffusion bonded ductile metal cladding plates uniformly covering the meat, the meat having a uniform high fuel loading comprising a content of uranium compound greater than about 45 Vol. % at a porosity not greater than about 10 Vol. %. In a first embodiment, the meat is a plurality of parallel wires of uranium compound. In a second embodiment, the meat is a dispersion compact containing uranium compound. The fuel plates are fabricated by a hot isostatic pressing process.

  15. Automated fuel pin loading system

    DOEpatents

    Christiansen, D.W.; Brown, W.F.; Steffen, J.M.

    An automated loading system for nuclear reactor fuel elements utilizes a gravity feed conveyor which permits individual fuel pins to roll along a constrained path perpendicular to their respective lengths. The individual lengths of fuel cladding are directed onto movable transports, where they are aligned coaxially with the axes of associated handling equipment at appropriate production stations. Each fuel pin can be be reciprocated axially and/or rotated about its axis as required during handling steps. The fuel pins are inerted as a batch prior to welding of end caps by one of two disclosed welding systems.

  16. Automated Loads Analysis System (ATLAS)

    NASA Technical Reports Server (NTRS)

    Gardner, Stephen; Frere, Scot; O’Reilly, Patrick

    2013-01-01

    ATLAS is a generalized solution that can be used for launch vehicles. ATLAS is used to produce modal transient analysis and quasi-static analysis results (i.e., accelerations, displacements, and forces) for the payload math models on a specific Shuttle Transport System (STS) flight using the shuttle math model and associated forcing functions. This innovation solves the problem of coupling of payload math models into a shuttle math model. It performs a transient loads analysis simulating liftoff, landing, and all flight events between liftoff and landing. ATLAS utilizes efficient and numerically stable algorithms available in MSC/NASTRAN.

  17. Characterization of salinity loads and selenium loads in the Smith Fork Creek region of the Lower Gunnison River Basin, western Colorado, 2008-2009

    USGS Publications Warehouse

    Richards, Rodney J.; Linard, Joshua I.; Hobza, Christopher M.

    2014-01-01

    The lower Gunnison River Basin of the Colorado River Basin has elevated salinity and selenium levels. The Colorado River Basin Salinity Control Act of June 24, 1974 (Public Law 93–320, amended by Public Law 98–569), authorized investigation of the Lower Gunnison Basin Unit Salinity Control Project by the U.S. Department of the Interior. The Bureau of Reclamation (Reclamation) and the Natural Resources Conservation Service are responsible for assessing and implementing measures to reduce salinity and selenium loading in the Colorado River Basin. Cost-sharing programs help farmers, ranchers, and canal companies improve the efficiency of water delivery systems and irrigation practices. The delivery systems (irrigation canals) have been identified as potential sources of seepage, which can contribute to salinity loading. Reclamation wants to identify seepage from irrigation systems in order to maximize the effectiveness of the various salinity-control methods, such as polyacrylamide lining and piping of irrigation canals programs. The U.S. Geological Survey, in cooperation with Reclamation, developed a study to characterize the salinity and selenium loading of seven subbasins in the Smith Fork Creek region and identify where control efforts can be maximized to reduce salinity and selenium loading. Total salinity loads ranged from 27.9±19.1 tons per year (t/yr) to 87,500±80,500 t/yr. The four natural subbasins—BkKm, RCG1, RCG2, and SF1—had total salinity loads of 27.9±19.1 t/yr, 371±248 t/yr, 2,180±1,590 t/yr, and 4,200±2,720 t/yr, respectively. The agriculturally influenced sites had salinity loads that ranged from 7,580±6,900 t/yr to 87,500±80,500 t/yr. Salinity loads for the subbasins AL1, B1, CK1, SF2, and SF3 were 7,580±6,900 t/yr; 28,300±26,700 t/yr; 48,700±36,100 t/yr; 87,500±80,900 t/yr; and 52,200±31,800 t/yr, respectively. The agricultural salinity load was separated into three components: tail water, deep percolation, and canal seepage

  18. System and method employing a minimum distance and a load feature database to identify electric load types of different electric loads

    DOEpatents

    Lu, Bin; Yang, Yi; Sharma, Santosh K; Zambare, Prachi; Madane, Mayura A

    2014-12-23

    A method identifies electric load types of a plurality of different electric loads. The method includes providing a load feature database of a plurality of different electric load types, each of the different electric load types including a first load feature vector having at least four different load features; sensing a voltage signal and a current signal for each of the different electric loads; determining a second load feature vector comprising at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the different electric loads; and identifying by a processor one of the different electric load types by determining a minimum distance of the second load feature vector to the first load feature vector of the different electric load types of the load feature database.

  19. Quantum dots formed in InSb/AlAs and AlSb/AlAs heterostructures

    NASA Astrophysics Data System (ADS)

    Abramkin, D. S.; Rumynin, K. M.; Bakarov, A. K.; Kolotovkina, D. A.; Gutakovskii, A. K.; Shamirzaev, T. S.

    2016-06-01

    The crystal structure of new self-assembled InSb/AlAs and AlSb/AlAs quantum dots grown by molecularbeam epitaxy has been investigated by transmission electron microscopy. The theoretical calculations of the energy spectrum of the quantum dots have been supplemented by the experimental data on the steady-state and time-resolved photoluminescence spectroscopy. Deposition of 1.5 ML of InSb or AlSb on the AlAs surface carried out in the regime of atomic-layer epitaxy leads to the formation of pseudomorphically strained quantum dots composed of InAlSbAs and AlSbAs alloys, respectively. The quantum dots can have the type-I and type-II energy spectra depending on the composition of the alloy. The ground hole state in the quantum dot belongs to the heavy-hole band and the localization energy of holes is much higher than that of electrons. The ground electron state in the type-I quantum dots belongs to the indirect X XY valley of the conduction band of the alloy. The ground electron state in the type-II quantum dots belongs to the indirect X valley of the conduction band of the AlAs matrix.

  20. First principles studies of ideal strength and bonding nature of AlN polymorphs in comparison to TiN

    NASA Astrophysics Data System (ADS)

    Zhang, R. F.; Sheng, S. H.; Veprek, S.

    2007-07-01

    The stress-strain relationships under tensile and shear loads and bonding nature of fcc (rocksalt)-, hcp (wurtzite)-AlN, and fcc (rocksalt)-TiN are calculated by first principles method. Compared to fcc-TiN, fcc-AlN shows similar anisotropy of tensile strengths, but lower shear strength is found in both AlN polymorphs. Based on the calculated electronic density of states, bonding nature for both AlN polymorphs is discussed. The hardness enhancement in TiN /AlN heterostructures and nanocomposites cannot be attributed to the difference of the ideal strength and bonding nature between fcc-AlN and hcp-AlN, but to the formation of semicoherent fcc-TiN/fcc-AlN interface.

  1. Combined load test apparatus for flat panels

    NASA Astrophysics Data System (ADS)

    McWithey, Robert R.; Martin, Carl J., Jr.; Cerro, Jeffrey A.

    1992-04-01

    Future hypersonic aircraft such as the National Aero-Space Plane and a high speed civil transport will require the design and use of efficient, highly-loaded, flat structural panels to achieve mission requirements. These panels will be subjected to severe combinations of in-plane mechanical distributed loads (i.e., normal loads in two perpendicular directions plus a shear load), in addition to pressure and thermal loads. A testing apparatus is provided for applying uniform combined in-plane stresses to a flat panel containing an interior test area. Actuators cause two sets of load rods to apply loads to the edge of the flat panel. The first set applies loads which are perpendicular to and independent of the loads applied by the second set. The loads are applied according to a cosine load distribution to obtain a uniform stress field within the test area. The flat panel may be rotated with respect to the applied loads to obtain a wide range of combined stresses in the test area. Movement outside the plane of the flat panel may be selectively prevented by connecting the flat panel to a restraining disk by support rods. The support rods then define the test area. A thermal load may be applied to one side of the flat panel and a pressure load may be applied to the other side. The novelty of this method is found in providing a testing apparatus which allows mechanical, thermal and pressure loads to be applied simultaneously to a flat panel for testing purposes.

  2. 1993 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1993-12-01

    The Loads and Resources Study is presented in three documents: (1) this summary of Federal system and Pacific Northwest region loads and resources; (2) a technical appendix detailing forecasted Pacific Northwest economic trends and loads, and (3) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The forecasted future electricity demands -- firm loads -- are subtracted from the projected capability of existing and {open_quotes}contracted for{close_quotes} resources to determine whether Bonneville Power Administration (BPA) and the region will be surplus or deficit. If resources are greater than loads in any particular year or month, there is a surplus of energy and/or capacity, which BPA can sell to increase revenues. Conversely, if firm loads exceed available resources, there is a deficit of energy and/or capacity, and additional conservation, contract purchases, or generating resources will be needed to meet load growth. The Pacific Northwest Loads and Resources Study analyzes the Pacific Northwest`s projected loads and available generating resources in two parts: (1) the loads and resources of the Federal system, for which BPA is the marketing agency; and (2) the larger Pacific Northwest regional power system, which includes loads and resource in addition to the Federal system. The loads and resources analysis in this study simulates the operation of the power system under the Pacific Northwest Coordination Agreement (PNCA) produced by the Pacific Northwest Coordinating Group. This study presents the Federal system and regional analyses for five load forecasts: high, medium-high, medium, medium-low, and low. This analysis projects the yearly average energy consumption and resource availability for Operating Years (OY) 1994--95 through 2003--04.

  3. Fabrication and Analysis of the Wear Properties of Hot-Pressed Al-Si/SiCp + Al-Si-Cu-Mg Metal Matrix Composite

    NASA Astrophysics Data System (ADS)

    Bang, Jeongil; Oak, Jeong-Jung; Park, Yong Ho

    2016-01-01

    The aim of this study was to characterize microstructures and mechanical properties of aluminum metal matrix composites (MMC's) prepared by powder metallurgy method. Consolidation of mixed powder with gas atomized Al-Si/SiCp powder and Al-14Si-2.5Cu-0.5Mg powder by hot pressing was classified according to sintering temperature and sintering time. Sintering condition was optimized using tensile properties of sintered specimens. Ultimate tensile strength of the optimized sintered specimen was 228 MPa with an elongation of 5.3% in longitudinal direction. In addition, wear properties and behaviors of the sintered aluminum-based MMC's were analyzed in accordance with vertical load and linear speed. As the linear speed and vertical load of the wear increased, change of the wear behavior occurred in order of oxidation of Al-Si matrix, formation of C-rich layer, Fe-alloying to matrix, and melting of the specimen

  4. Low reflectance radio frequency load

    DOEpatents

    Ives, R. Lawrence; Mizuhara, Yosuke M

    2014-04-01

    A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

  5. Loading of wellbores with explosives

    SciTech Connect

    Loving, F.A.; Simmons, W.J.

    1983-04-26

    Bags of explosive are loaded rapidly into deep wellbores by suspending a rigid positioning tube partway into the wellbore, and loading the bags into the tube, the bags being prevented from dropping through the open bottom end of the tube by a cord attached to the lowermost bag and secured at the upper end of the tube when the tube-suspending cable is in tension by a cordsecuring/releasing means, E.G., a pivotable bar having a hook on one end. When the bag-laden tube is lowered to the bottom of the wellbore, or to a column of bags previously placed therein, the tension on the cable is relaxed and the cord is released, allowing the positioning tube thereafter to be raised to the surface for re-use, leaving the cord and bags in the wellbore. Freedom of the bag-supporting cord to move with respect to the positioning tube when the latter is raised to the surface is assured by threading the cord through plastic tubing mounted to the wall of the positioning tube and releasable therefrom for reuse.

  6. Phloem loading: an integrated approach

    SciTech Connect

    Wilson, C.

    1986-01-01

    This study focuses on the regulation of sucrose transport across the plasmalemma. Initially, we re-examined the use of leaf discs to study the kinetics of phloem loading using Allium cepa leaves. All tissues exhibited the same linear plus saturable profile as Beta vulgaris, except fructose uptake into the inner parenchyma and bundle-sheath cells; in this case the response was linear. These results indicate that all tissues of the leaf retrieve exogenous sucrose such that kinetics from leaf discs cannot be taken to represent phloem loading per se. We continued our study by investigating the influence of internal sugars on sugar transport across the plasmalemma. We found that if internal sugars were manipulated by heat-girdling techniques or DCMU treatment there was no appreciable change in sucrose influx. However, longer term heat-girdling decreased sucrose uptake. These data indicate that carbohydrate partitioning among the chloroplast, cytosol, and vacuole modulates cytosolic sugar levels. One interesting discovery was that leaves excised from the plant and allowed to undergo their normal day/night cycle do not transfer (/sup 14/C) sucrose to their minor veins.

  7. Liposome-Loaded Cell Backpacks.

    PubMed

    Polak, Roberta; Lim, Rosanna M; Beppu, Marisa M; Pitombo, Ronaldo N M; Cohen, Robert E; Rubner, Michael F

    2015-12-30

    Cell backpacks, or micron-scale patches of a few hundred nanometers in thickness fabricated by layer-by-layer (LbL) assembly, are potentially useful vehicles for targeted drug delivery on the cellular level. In this work, echogenic liposomes (ELIPs) containing the anticancer drug doxorubicin (DOX) are embedded into backpacks through electrostatic interactions and LbL assembly. Poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA)n , and poly(diallyldimethylammonium chloride)/poly(styrene sulfonate) (PDAC/SPS)n film systems show the greatest ELIP incorporation of the films studied while maintaining the structural integrity of the vesicles. The use of ELIPs for drug encapsulation into backpacks facilitates up to three times greater DOX loading compared to backpacks without ELIPs. Cytotoxicity studies reveal that monocyte backpack conjugates remain viable even after 72 h, demonstrating promise as drug delivery vehicles. Because artificial vesicles can load many different types of drugs, ELIP containing backpacks offer a unique versatility for broadening the range of possible applications for cell backpacks. PMID:26616471

  8. APS high heat load monochromator

    SciTech Connect

    Lee, W.K.; Mills, D.

    1993-02-01

    This document contains the design specifications of the APS high heat load (HHL) monochromator and associated accessories as of February 1993. It should be noted that work is continuing on many parts of the monochromator including the mechanical design, crystal cooling designs, etc. Where appropriate, we have tried to add supporting documentation, references to published papers, and calculations from which we based our decisions. The underlying philosophy behind performance specifications of this monochromator was to fabricate a device that would be useful to as many APS users as possible, that is, the design should be as generic as possible. In other words, we believe that this design will be capable of operating on both bending magnet and ID beamlines (with the appropriate changes to the cooling and crystals) with both flat and inclined crystal geometries and with a variety of coolants. It was strongly felt that this monochromator should have good energy scanning capabilities over the classical energy range of about 4 to 20 keywith Si (111) crystals. For this reason, a design incorporating one rotation stage to drive both the first and second crystals was considered most promising. Separate rotary stages for the first and second crystals can sometimes provide more flexibility in their capacities to carry heavy loads (for heavily cooled first crystals or sagittal benders of second crystals), but their tuning capabilities were considered inferior to the single axis approach.

  9. Electric load management and energy conservation

    NASA Technical Reports Server (NTRS)

    Kheir, N. A.

    1976-01-01

    Electric load management and energy conservation relate heavily to the major problems facing power industry at present. The three basic modes of energy conservation are identified as demand reduction, increased efficiency and substitution for scarce fuels. Direct and indirect load management objectives are to reduce peak loads and have future growth in electricity requirements in such a manner to cause more of it to fall off the system's peak. In this paper, an overview of proposed and implemented load management options is presented. Research opportunities exist for the evaluation of socio-economic impacts of energy conservation and load management schemes specially on the electric power industry itself.

  10. Medical application of 26Al

    NASA Astrophysics Data System (ADS)

    Steinhausen, C.; Gerisch, P.; Heisinger, B.; Hohl, Ch.; Kislinger, G.; Korschinek, G.; Niedermayer, M.; Nolte, E.; Dumitru, M.; Alvarez-Brückmann, M.; Schneider, M.; Ittel, T. H.

    1996-06-01

    Accelerator mass spectrometry (AMS) measurements with 26Al as tracer were performed in order to study the aluminium metabolism and anomalies in the human body and in rats. In particular, the differences between healthy volunteers and patients with renal failure were investigated. The obtained data points of 26Al in blood and urine were described by an open compartment model with three peripheral compartments. It was found that the minimum of peripheral compartments needed to describe 26Al concentrations in blood and urine over a time period of three years is at least three.

  11. Residual stresses in continuous graphite fiber Al metal matrix composites

    NASA Technical Reports Server (NTRS)

    Park, Hun Sub; Zong, Gui Sheng; Marcus, Harris L.

    1988-01-01

    The residual stresses in graphite fiber reinforced aluminum (Gr/Al) composites with various thermal histories are measured using X-ray diffraction (XRD) methods. The XRD stress analysis is based on the determination of lattice strains by precise measurements of the interplanar spacings in different directions of the sample. The sample is a plate consisting of two-ply P 100 Gr/Al 6061 precursor wires and Al 6061 overlayers. Prior to XRD measurement, the 6061 overlayers are electrochemically removed. In order to calibrate the relationship between stress magnitude and lattice spacing shift, samples of Al 6061 are loaded at varying stress levels in a three-point bend fixture, while the stresses are simultaneously determined by XRD and surface-attached strain gages. The stresses determined by XRD closely match those determined by the strain gages. Using these calibrations, the longitudinal residual stresses of P 100 Gr/Al 6061 composites are measured for various heat treatments, and the results are presented.

  12. Detection of Unexpected High Correlations between Balance Calibration Loads and Load Residuals

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Volden, T.

    2014-01-01

    An algorithm was developed for the assessment of strain-gage balance calibration data that makes it possible to systematically investigate potential sources of unexpected high correlations between calibration load residuals and applied calibration loads. The algorithm investigates correlations on a load series by load series basis. The linear correlation coefficient is used to quantify the correlations. It is computed for all possible pairs of calibration load residuals and applied calibration loads that can be constructed for the given balance calibration data set. An unexpected high correlation between a load residual and a load is detected if three conditions are met: (i) the absolute value of the correlation coefficient of a residual/load pair exceeds 0.95; (ii) the maximum of the absolute values of the residuals of a load series exceeds 0.25 % of the load capacity; (iii) the load component of the load series is intentionally applied. Data from a baseline calibration of a six-component force balance is used to illustrate the application of the detection algorithm to a real-world data set. This analysis also showed that the detection algorithm can identify load alignment errors as long as repeat load series are contained in the balance calibration data set that do not suffer from load alignment problems.

  13. 14 CFR 23.511 - Ground load; unsymmetrical loads on multiple-wheel units.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... multiple-wheel units. 23.511 Section 23.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Structure Ground Loads § 23.511 Ground load; unsymmetrical loads on multiple-wheel units... distribution, to the dual wheels and tires in each dual wheel landing gear unit. (c) Deflated tire loads....

  14. 14 CFR 23.511 - Ground load; unsymmetrical loads on multiple-wheel units.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... multiple-wheel units. 23.511 Section 23.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Structure Ground Loads § 23.511 Ground load; unsymmetrical loads on multiple-wheel units... distribution, to the dual wheels and tires in each dual wheel landing gear unit. (c) Deflated tire loads....

  15. 14 CFR 23.511 - Ground load; unsymmetrical loads on multiple-wheel units.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... multiple-wheel units. 23.511 Section 23.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Structure Ground Loads § 23.511 Ground load; unsymmetrical loads on multiple-wheel units... distribution, to the dual wheels and tires in each dual wheel landing gear unit. (c) Deflated tire loads....

  16. 14 CFR 23.511 - Ground load; unsymmetrical loads on multiple-wheel units.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... multiple-wheel units. 23.511 Section 23.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Structure Ground Loads § 23.511 Ground load; unsymmetrical loads on multiple-wheel units... distribution, to the dual wheels and tires in each dual wheel landing gear unit. (c) Deflated tire loads....

  17. Crack-closure and crack-growth measurements in surface-flawed titanium alloy Ti6Al-4V

    NASA Technical Reports Server (NTRS)

    Elber, W.

    1975-01-01

    The crack-closure and crack-growth characteristics of the titanium alloy Ti-6Al-4V were determined experimentally on surface-flawed plate specimens. Under cyclic loading from zero to tension, cracks deeper than 1 mm opened at approximately 50 percent of the maximum load. Cracks shallower than 1 mm opened at higher loads. The correlation between crack-growth rate and the total stress-intensity range showed a lower threshold behavior. This behavior was attributed to the high crack-opening loads at short cracks because the lower threshold was much less evident in correlations between the crack-growth rates and the effective stress-intensity range.

  18. High payload six-axis load sensor

    DOEpatents

    Jansen, John F.; Lind, Randall F.

    2003-01-01

    A repairable high-payload six-axis load sensor includes a table, a base, and at least three shear-pin load transducers removably mounted between the table and the base. Removable mounting permits easy replacement of damaged shear pins. Preferably, the shear-pin load transducers are responsive to shear forces imparted along the two axes perpendicular to an axis of minimum sensitivity characteristic of the transducer. Responsive to an applied shear force, each shear-pin load transducer can produce an electrical signal proportional to the reaction force. The load sensor can further include a structure for receiving the proportional electrical signals and computing the applied load corresponding to the proportional electrical signals. The computed load can be expressed in terms of a three-dimensional XYZ Cartesian coordinate system.

  19. PEP-II B-Factory prototype higher order mode load design

    SciTech Connect

    Pendleton, R.; Ko, K.; Ng, N.

    1995-10-01

    To reduce the impedance of the cavity higher order modes, (HOM`s), a compact broad-band, low-reflection, waveguide load is required with a VSWR less than 2:1 in the frequency range 714 MHz to 2500 MHz. The load must also work in the high vacuum of the cavity, and be capable of dissipating up to 10 kW of power which is generated by the interaction of the beam with the cavity HOM`s and which is directed to each load assembly. A prototype load assembly is being fabricated which uses the lossy ceramic Al-N with 7% by weight glassy carbon to absorb the microwave power.

  20. Characteristics of Pt-K/MgAl2O4 lean NOx trap catalysts

    SciTech Connect

    Kim, Do Heui; Mudiyanselage, Kumudu K.; Szanyi, Janos; Zhu, Haiyang; Kwak, Ja Hun; Peden, Charles HF

    2012-04-30

    We report the various characteristics of Pt-K/MgAl{sub 2}O{sub 4} lean NOx trap (LNT) catalysts including the effect of K loading on nitrate formation/decomposition, NOx storage activity and durability. Upon the adsorption of NO{sub 2} on K/MgAl{sub 2}O{sub 4} samples, potassium nitrates formed on Mg-related sites in MgAl{sub 2}O{sub 4} support are observed, in addition to the typical two potassium nitrates (ionic and bidentate) formed also on Al{sub 2}O{sub 3} supported sample. Based on NO{sub 2} TPD and FTIR results, the Mg-bound KNO{sub 3} thermally decompose at higher temperature than Al-bound KNO{sub 3}, implying its superior thermal stability. At a potassium loading of 5wt%, the temperature of maximum NOx uptake (T{sub max}) is 300 C. Increasing the potassium loading from 5wt% to 10 wt%, the T{sub max} gradually shifted from 300 C to 450 C, indicating the dependence of T{sub max} on the potassium loading. However, increase in potassium loading above 10 wt% only gives rise to the reduction in the overall NOx storage capacity. This work also underlines the obstacles these materials have prior to their practical application (e.g., durability and sulfur poisoning/ removal). This work provides fundamental understanding of Pt-K/MgAl{sub 2}O{sub 4}-based lean NOx trap catalysts, which could be good candidates for high temperature LNT applications.

  1. Sorptive stabilization of organic matter by amorphous Al hydroxide

    NASA Astrophysics Data System (ADS)

    Schneider, M. P. W.; Scheel, T.; Mikutta, R.; van Hees, P.; Kaiser, K.; Kalbitz, K.

    2010-03-01

    Amorphous Al hydroxides (am-Al(OH) 3) strongly sorb and by this means likely protect dissolved organic matter (OM) against microbial decay in soils. We carried out batch sorption experiments (pH 4.5; 40 mg organic C L -1) with OM extracted from organic horizons under a Norway spruce and a European beech forest. The stabilization of OM by sorption was analyzed by comparing the CO 2 mineralized during the incubation of sorbed and non-sorbed OM. The mineralization of OM was evaluated based in terms of (i) the availability of the am-Al(OH) 3, thus surface OM loadings, (ii) spectral properties of OM, and (iii) the presence of phosphate as a competitor for OM. This was done by varying the solid-to-solution ratio (SSR = 0.02-1.2 g L -1) during sorption. At low SSRs, hence limited am-Al(OH) 3 availability, only small portions of dissolved OM were sorbed; for OM from Oa horizons, the mineralization of the sorbed fraction exceeded that of the original dissolved OM. The likely reason is competition with phosphate for sorption sites favouring the formation of weak mineral-organic bindings and the surface accumulation of N-rich, less aromatic and less complex OM. This small fraction controlled the mineralization of sorbed OM even at higher SSRs. At higher SSRs, i.e., with am-Al(OH) 3 more available, competition of phosphate decreased and aromatic compounds were sorbed selectively, which resulted in pronounced resistance of sorbed OM against decay. The combined OC mineralization of sorbed and non-sorbed OM was 12-65% less than that of the original DOM. Sorbed OM contributed only little to the overall OC mineralization. Stabilization of OC increased in direct proportion to am-Al(OH) 3 availability, despite constant aromatic C (˜30%). The strong stabilization at higher mineral availability is primarily governed by strong Al-OM bonds formed under less competitive conditions. Due to these strong bonds and the resulting strong stabilization, the surface loading, a proxy for the

  2. In memory of Al Cameron

    NASA Astrophysics Data System (ADS)

    Cowan, John; Truran, James W.

    Al Cameron, who died recently (October 3, 2005) at 80, was one of the giants in astrophysics. His insights were profound and his interests were wide-ranging. Originally trained as a nuclear physicist, he made major contributions in a number of fields, including nuclear reactions in stars, nucleosynthesis, the abundances of the elements in the Solar System, and the origin of the Solar System and the Moon. In 1957, Cameron and, independently, Burbidge, Burbidge, Fowler and Hoyle, wrote seminal papers on nuclear astrophysics. Most of our current ideas concerning ele- ment formation in stars have followed from those two pioneering and historical works. Al also made many contributions in the field of Solar System physics. Particularly noteworthy in this regard was Cameron's work on the formation of the Moon. Al was also a good friend and mentor of young people. Al Cameron will be missed by many in the community both for his scientific contributions and for his friendship.

  3. Decomposition of Rare Earth Loaded Resin Particles

    SciTech Connect

    Voit, Stewart L; Rawn, Claudia J

    2010-09-01

    resin is made of sulfonic acid functional groups attached to a styrene divinylbenzene copolymer lattice (long chained hydrocarbon). The metal cation binds to the sulfur group, then during thermal decomposition in air the hydrocarbons will form gaseous species leaving behind a spherical metal-oxide particle. Process development for resin applications with radioactive materials is typically performed using surrogates. For americium and curium, a trivalent metal like neodymium can be used. Thermal decomposition of Nd-loaded resin in air has been studied by Hale. Process conditions were established for resin decomposition and the formation of Nd{sub 2}O{sub 3} particles. The intermediate product compounds were described using x-ray diffraction (XRD) and wet chemistry. Leskela and Niinisto studied the decomposition of rare earth (RE) elements and found results consistent with Hale. Picart et al. demonstrated the viability of using a resin loading process for the fabrication of uranium-actinide mixed oxide microspheres for transmutation of minor actinides in a fast reactor. For effective transmutation of actinides, it will be desirable to extend the in-reactor burnup and minimize the number of recycles of used actinide materials. Longer burn times increases the chance of Fuel Clad Chemical or Mechanical Interaction (FCCI, FCMI). Sulfur is suspected of contributing to Irradiation Assisted Stress Corrosion Cracking (IASCC) thus it is necessary to maximize the removal of sulfur during decomposition of the resin. The present effort extends the previous work by quantifying the removal of sulfur during the decomposition process. Neodymium was selected as a surrogate for trivalent actinide metal cations. As described above Nd was dissolved in nitric acid solution then contacted with the AG-50W resin column. After washing the column, the Nd-resin particles are removed and dried. The Nd-resin, seen in Figure 1 prior to decomposition, is ready to be converted to Nd oxide microspheres.

  4. Common source-multiple load vs. separate source-individual load photovoltaic system

    NASA Technical Reports Server (NTRS)

    Appelbaum, Joseph

    1989-01-01

    A comparison of system performance is made for two possible system setups: (1) individual loads powered by separate solar cell sources; and (2) multiple loads powered by a common solar cell source. A proof for resistive loads is given that shows the advantage of a common source over a separate source photovoltaic system for a large range of loads. For identical loads, both systems perform the same.

  5. Artificial neural network based hourly load forecasting for decentralized load management

    SciTech Connect

    Mandal, J.K.; Sinha, A.K.

    1995-12-31

    Decentralized load management is an essential part of the power system operation. Forecasting load demand at the substation level is generally more difficult and less accurate compared to forecasting total system load demand. In this paper, Multi-Layered Feed Forward (MLFF) neural network is used to predict the bus-load demand at the substation level. The MLFF network is trained using Back-Propagation (BP) algorithm with adaptive learning technique. The algorithm is tested for two systems having different load patterns.

  6. Advantages of MgAlOx over gamma-Al2O3 as a support material for potassium-based high temperature lean NOx traps

    SciTech Connect

    Luo, Jinyong; Gao, Feng; Karim, Ayman M.; Xu, Pinghong; Browning, Nigel D.; Peden, Charles HF

    2015-08-07

    MgAlOx mixed oxides were employed as supports for potassium-based lean NOx traps (LNTs) targeted for high temperature applications. Effects of support compositions, K/Pt loadings, thermal aging and catalyst regeneration on NOx storage capacity were systematically investigated. The catalysts were characterized by XRD, NOx-TPD, TEM, STEM-HAADF and in-situ XAFS. The results indicate that MgAlOx mixed oxides have significant advantages over conventional gamma-Al2O3-supports for LNT catalysts, in terms of high temperature NOx trapping capacity and thermal stability. First, as a basic support, MgAlOx stabilizes stored nitrates (in the form of KNO3) to much higher temperatures than mildly acidic gamma-Al2O3. Second, MgAlOx minimizes Pt sintering during thermal aging, which is not possible for gamma-Al2O3 supports. Notably, combined XRD, in-situ XAFS and STEM-HAADF results indicate that Pt species in the thermally aged Pt/MgAlOx samples are finely dispersed in the oxide matrix as isolated atoms. This strong metal-support interaction stabilizes Pt and minimizes the extent of sintering. However, such strong interactions result in Pt oxidation via coordination with the support so that NO oxidation activity can be adversely affected after aging which, in turn, decreases NOx trapping ability for these catalysts. Interestingly, a high-temperature reduction treatment regenerates essentially full NOx trapping performance. In fact, regenerated Pt/K/MgAlOx catalyst exhibits much better NOx trapping performance than fresh Pt/K/Al2O3 LNTs over the entire temperature range investigated here. In addition to thermal aging, Pt/K loading effects were systemically studied over the fresh samples. The results indicate that NOx trapping is kinetically limited at low temperatures, while thermodynamically limited at high temperatures. A simple conceptual model was developed to explain the Pt and K loading effects on NOx storage. An optimized K loading, which allows balancing between the

  7. High heat load synchrotron optics

    SciTech Connect

    Mills, D.M.

    1992-08-01

    Third generation synchrotron radiation sources currently being constructed worldwide will produce x-ray beams of unparalleled power and power density these high heat fluxes coupled with the stringent dimensional requirements of the x-ray optical components pose a prodigious challenge to designers of x-ray optical elements, specifically x-ray mirrors and crystal monochromators. Although certain established techniques for the cooling of high heat flux components can be directly applied to this problem, the thermal management of high heat load x-ray optical components has several unusual aspects that may ultimately lead to unique solutions. This manuscript attempts to summarize the various approaches currently being applied to this undertaking and to point out the areas of research that require further development.

  8. Load limiting parachute inflation control

    SciTech Connect

    Redmond, J.; Hinnerichs, T.; Parker, G.

    1994-01-01

    Excessive deceleration forces experienced during high speed deployment of parachute systems can cause damage to the payload and the canopy fabric. Conventional reefing lines offer limited relief by temporarily restricting canopy inflation and limiting the peak deceleration load. However, the open-loop control provided by existing reefing devices restrict their use to a specific set of deployment conditions. In this paper, the sensing, processing, and actuation that are characteristic of adaptive structures form the basis of three concepts for active control of parachute inflation. These active control concepts are incorporated into a computer simulation of parachute inflation. Initial investigations indicate that these concepts promise enhanced performance as compared to conventional techniques for a nominal release. Furthermore, the ability of each controller to adapt to off-nominal release conditions is examined.

  9. Obsidian hydration dates glacial loading?

    PubMed

    Friedman, I; Pierce, K L; Obradovich, J D; Long, W D

    1973-05-18

    Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming. The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow. PMID:17806883

  10. High voltage load resistor array

    DOEpatents

    Lehmann, Monty Ray

    2005-01-18

    A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

  11. Tar loads on Omani beaches

    SciTech Connect

    Badawy, M.I.; Al-Harthy, F.T. )

    1991-11-01

    Owing to Oman's geographic position and long coastal line, the coastal areas of Oman are particularly vulnerable to oil pollution from normal tanker operations, illegal discharges, and accidental spills as well as local sources of oil input. UNEP carried out a survey on the coasts of Oman to determine the major sources of oil pollution and concluded that the major shoreline pollution problems in Oman arose from operational discharges of oil from passing vessels traffic. The oil, because of the high sea and air temperatures in the area, was subjected to relatively high rates of evaporation and photo-oxidation and tended to arrive at the coast as heavy petroleum particulate residues (tar balls). The aim of the present study was to measure the loads of tar balls in Omani coastal areas and to identify the source of oil pollutants on beaches.

  12. Load distribution in native cellulose.

    PubMed

    Hinterstoisser, Barbara; Akerholm, Margaretha; Salmén, Lennart

    2003-01-01

    The properties of cellulose materials are dependent on interactions between and within the cellulose chains. To investigate the deformation behavior of cellulose and its relation to molecular straining, sheets with fibers oriented preferably in one direction were studied by dynamic FT-IR spectroscopy. Celluloses with different origins (spruce pulp, Cladophora cellulose, cotton linters) were used. The sheets were stretched sinusoidally at low strains and small amplitudes while being irradiated with polarized infrared radiation. The cellulose fibers showed mainly an elastic response. The cellulose fibers showed mainly an elastic response. The glucose rings and the C-O-C bridges connecting adjacent rings, as well as the O(3)H.O(5) intramolecular hydrogen bonds are the components mainly deformed under stress, whereas the O(2)H.O(6) intramolecular hydrogen bonds play a minor role. The load distribution was also found to be different in the different allomorphic forms of cellulose I, namely, I(alpha) and I(beta).

  13. Obsidian hydration dates glacial loading?

    PubMed

    Friedman, I; Pierce, K L; Obradovich, J D; Long, W D

    1973-05-18

    Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming. The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow.

  14. Obsidian hydration dates glacial loading?

    USGS Publications Warehouse

    Friedman, I.; Pierce, K.L.; Obradovich, J.D.; Long, W.D.

    1973-01-01

    Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming . The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow.

  15. Bulk Modulus Capacitor Load Cells

    SciTech Connect

    Dickey, C.E.

    1990-04-01

    Measurement of forces present at various locations within the SSC Model Dipole collared coil assembly is of great practical interest to development engineers. Of particular interest are the forces between coils at the parting plane and forces that exist between coils and pole pieces. It is also desired to observe these forces under the various conditions that a magnet will experience such as: during the collaring process, post-collaring, under the influence of cryogens, and during field excitation. A twenty eight thousandths of an inch thick capacitor load cell which utilizes the hydrostatic condition of a stressed plastic dielectric has been designed. These cells are currently being installed on SSC Model Dipoles. The theory, development, and application of these cells will be discussed.

  16. Self loading wood burning stove

    SciTech Connect

    Gonzales, E.; Spector, G.

    1987-08-25

    A self loading wood burning stove is described which comprises: (a) a fire box having an air intake vent for supplying a flow of combustible air therin an an exhaust conduit in flow communication with the fire box for exhausting combustion gases therefrom: (b) a storage bin for retaining a plurality of logs, the storage bin having a generally zig-zag vertically arranged compartment for holding a zig-zag row of the logs, the storage bin having a log entry opening at upper portion and a pair of pivotable doors at lower portion for dispensing the logs individually therefrom; and (c) means for delivering the logs from the doors of the storage bin to the fire box of the stove, wherein the delivering means comprises: (d) a conveyor for receiving the logs from the doors of the storage bin and conducting the logs upwardly in a substantially angular fashion; and (e) means for placing the logs from the conveyor into upper portion of the fire box; wherein the conveyor comprises: (f) a plurality of rollers; (g) an endless belt formed around the rollers, the belt having a plurality of push lugs; and (h) a motor to driven one of the rollers to operate the belt so that the push lug will drive the log upwardly; wherein the placing means comprises: (i) a housing having a plurality of legs mounted to the upper portion of the fire box, the housing having a log guide roller in rotatable contact with the belt of the conveyor and a pair of spring loaded trap doors that are opened by weight of the log so that log will far therethrough; and (j) the first box having an inclined top and a pivotable top door that is opened by weight of the log so that the log will roll therein.

  17. Active load control using microtabs

    NASA Astrophysics Data System (ADS)

    Yen, Dora Te-Lun

    2001-11-01

    Micro-electro-mechanical (MEM) translational tabs are introduced for enhancing and controlling the aerodynamic loading on lifting surfaces. These microtabs are mounted near the trailing edge of lifting surfaces, retract and extend approximately normal to the surface and have a maximum deployment height on the order of the boundary-layer thickness. Deployment of the device effectively modifies the camber distribution of the lifting surface and hence, the lift generated. The effect of the microtabs on lift is shown to be as powerful as conventional control surfaces with lift changes of 30%--50% in the linear range of the lift curve using a tab with a height of 1% of airfoil chord placed at 5% of chord upstream of the trailing edge on the lower surface. A multi-disciplinary approach incorporating aspects of experimental and computational aerodynamics, mechanical design and microfabrication techniques has been taken to develop and test a "proof of concept" model. Flow simulations, using a Reynolds-averaged Navier Stokes solver, have been conducted to optimize the size and placement of the devices based on trailing edge volume constraints. Numerical and experimental wind tunnel results are in good agreement, and both confirm that these micro-scale devices create macro-scale changes in aerodynamic loading. Application of this rather simple but innovative lift control system based on microfabrication techniques introduces a robust, dynamic control device and will allow for the miniaturization of conventional high lift and control systems. The result is a significant reduction in typical control system weight, complexity and cost. Also due to the minute size of these tabs, their activation and response times are much faster than that of conventional trailing edge devices. The "proof of concept" tab design, fabrication techniques, computational and experimental setup, and test results using a representative airfoil are presented in this research. (For more information, see

  18. Comparing the Thermodynamic Behaviour of Al(1)+ZrO2(s) to Al(1)+Al2O3(s)

    NASA Technical Reports Server (NTRS)

    Copland, Evan

    2004-01-01

    In an effort to better determine the thermodynamic properties of Al(g) and Al2O(g). the vapor in equilibrium with Al(l)+ZrO2(s) was compared to the vapor in equilibrium with Al(l)+Al2O3(s) over temperature range 1197-to-1509K. The comparison was made directly by Knudsen effusion-cell mass spectrometry with an instrument configured for a multiple effusion-cell vapor source (multi-cell KEMS). Second law enthalpies of vaporization of Al(g) and Al2O(g) together with activity measurements show that Al(l)+ZrO2(s) is thermodynamically equivalent to Al(l)+Al2O3(s), indicating Al(l) remained pure and Al2O3(s) was present in the ZrO2-cell. Subsequent observation of the Al(l)/ZrO2 and vapor/ZrO2 interfaces revealed a thin Al2O3-layer had formed, separating the ZrO2-cell from Al(l) and Al(g)+Al2O(g), effectively transforming it into an Al2O3 effusion-cell. This behavior agrees with recent observations made for Beta-NiAl(Pt) alloys measured in ZrO2 effusion-cell.

  19. Load carriage, human performance, and employment standards.

    PubMed

    Taylor, Nigel A S; Peoples, Gregory E; Petersen, Stewart R

    2016-06-01

    The focus of this review is on the physiological considerations necessary for developing employment standards within occupations that have a heavy reliance on load carriage. Employees within military, fire fighting, law enforcement, and search and rescue occupations regularly work with heavy loads. For example, soldiers often carry loads >50 kg, whilst structural firefighters wear 20-25 kg of protective clothing and equipment, in addition to carrying external loads. It has long been known that heavy loads modify gait, mobility, metabolic rate, and efficiency, while concurrently elevating the risk of muscle fatigue and injury. In addition, load carriage often occurs within environmentally stressful conditions, with protective ensembles adding to the thermal burden of the workplace. Indeed, physiological strain relates not just to the mass and dimensions of carried objects, but to how those loads are positioned on and around the body. Yet heavy loads must be borne by men and women of varying body size, and with the expectation that operational capability will not be impinged. This presents a recruitment conundrum. How do employers identify capable and injury-resistant individuals while simultaneously avoiding discriminatory selection practices? In this communication, the relevant metabolic, cardiopulmonary, and thermoregulatory consequences of loaded work are reviewed, along with concomitant impediments to physical endurance and mobility. Also emphasised is the importance of including occupation-specific clothing, protective equipment, and loads during work-performance testing. Finally, recommendations are presented for how to address these issues when evaluating readiness for duty. PMID:27277563

  20. Impedance matching between ventricle and load.

    PubMed

    Piene, H

    1984-01-01

    Impedance matching in the cardiovascular system is discussed in light of two models of ventricle and load: a Thevenin equivalent consisting of a hydromotive pressure source and an internal, source resistance and compliance in parallel; and a time-varying compliance filled from a constant pressure source and ejecting into a load of three components, a central resistor, a compliance, and a peripheral resistance. According to the Thevenin analog, the energy source and the load are matched when the load resistance is T/t times the internal source resistance (T is total cycle length, t is systolic time interval). Both from this model and from the variable compliance model it appears that optimum matching between source and load depends on the compliance of the Windkessel, as low compliance shifts the matching load resistance to a low value. Animal experiments (isolated cat hearts) indicated that both left and right ventricles at normal loads work close to their maxima of output hydraulic power, and, according to experiments in the right ventricle, maximum power output is related to load resistance and compliance as predicted by the above models. From an experimentally determined relationship among instantaneous ventricular pressure and volume (right ventricle of isolated cat hearts), an optimum load impedance was calculated on the basis of the assumption that the ratio between stroke work and static, potential energy developed in the ventricular cavity is maximum. The optimum load impedance found by this procedure closely resembles the normal input impedance of the cat lung vessel bed. PMID:6507966

  1. Tendon fatigue in response to mechanical loading

    PubMed Central

    Andarawis-Puri, N.; Flatow, E. L.

    2015-01-01

    Tendinopathies are commonly attributable to accumulation of sub-rupture fatigue damage from repetitive use. Data is limited to late stage disease from patients undergoing surgery, motivating development of animal models, such as ones utilizing treadmill running or repetitive reaching, to investigate the progression of tendinopathies. We developed an in vivo model using the rat patellar tendon that allows control of the loading directly applied to the tendon. This manuscript discusses the response of tendons to fatigue loading and applications of our model. Briefly, the fatigue life of the tendon was used to define low, moderate and high levels of fatigue loading. Morphological assessment showed a progression from mild kinks to fiber disruption, for low to high level fatigue loading. Collagen expression, 1 and 3 days post loading, showed more modest changes for low and moderate than high level fatigue loading. Protein and mRNA expression of Ineterleukin-1β and MMP-13 were upregulated for moderate but not low level fatigue loading. Moderate level (7200 cycles) and 100 cycles of fatigue loading resulted in a catabolic and anabolic molecular profile respectively, at both 1 and 7 days post loading. Results suggest unique mechanisms for different levels of fatigue loading that are distinct from laceration. PMID:21625047

  2. Load carriage, human performance, and employment standards.

    PubMed

    Taylor, Nigel A S; Peoples, Gregory E; Petersen, Stewart R

    2016-06-01

    The focus of this review is on the physiological considerations necessary for developing employment standards within occupations that have a heavy reliance on load carriage. Employees within military, fire fighting, law enforcement, and search and rescue occupations regularly work with heavy loads. For example, soldiers often carry loads >50 kg, whilst structural firefighters wear 20-25 kg of protective clothing and equipment, in addition to carrying external loads. It has long been known that heavy loads modify gait, mobility, metabolic rate, and efficiency, while concurrently elevating the risk of muscle fatigue and injury. In addition, load carriage often occurs within environmentally stressful conditions, with protective ensembles adding to the thermal burden of the workplace. Indeed, physiological strain relates not just to the mass and dimensions of carried objects, but to how those loads are positioned on and around the body. Yet heavy loads must be borne by men and women of varying body size, and with the expectation that operational capability will not be impinged. This presents a recruitment conundrum. How do employers identify capable and injury-resistant individuals while simultaneously avoiding discriminatory selection practices? In this communication, the relevant metabolic, cardiopulmonary, and thermoregulatory consequences of loaded work are reviewed, along with concomitant impediments to physical endurance and mobility. Also emphasised is the importance of including occupation-specific clothing, protective equipment, and loads during work-performance testing. Finally, recommendations are presented for how to address these issues when evaluating readiness for duty.

  3. An initiation phenomenon of Al-PTFE under quasi-static compression

    NASA Astrophysics Data System (ADS)

    Feng, Bin; Fang, Xiang; Li, Yu-chun; Wang, Huai-xi; Mao, Yi-ming; Wu, Shuang-zhang

    2015-09-01

    Generally, the Al-PTFE is thought to be inert under quasi-static or static loads. However, here we reported an initiation phenomenon of Al-PTFE under quasi-static compression. SEM and finite element simulation results suggest that the initiation was directly related to crack propagation and sliding interfaces in severely sheared regions. Calculation results show that the deformation induced temperature rise is only 28.6 °C and no melted Al or PTFE were observed in recovered samples in the critical initiation state. Therefore, the initiation is more like a mechanochemical process rather than a thermochemical one.

  4. Random spectrum loading of dental implants: An alternative approach to functional performance assessment.

    PubMed

    Shemtov-Yona, K; Rittel, D

    2016-09-01

    The fatigue performance of dental implants is usually assessed on the basis of cyclic S/N curves. This neither provides information on the anticipated service performance of the implant, nor does it allow for detailed comparisons between implants unless a thorough statistical analysis is performed, of the kind not currently required by certification standards. The notion of endurance limit is deemed to be of limited applicability, given unavoidable stress concentrations and random load excursions, that all characterize dental implants and their service conditions. We propose a completely different approach, based on random spectrum loading, as long used in aeronautical design. The implant is randomly loaded by a sequence of loads encompassing all load levels it would endure during its service life. This approach provides a quantitative and comparable estimate of its performance in terms of lifetime, based on the very fact that the implant will fracture sooner or later, instead of defining a fatigue endurance limit of limited practical application. Five commercial monolithic Ti-6Al-4V implants were tested under cyclic, and another 5 under spectrum loading conditions, at room temperature and dry air. The failure modes and fracture planes were identical for all implants. The approach is discussed, including its potential applications, for systematic, straightforward and reliable comparisons of various implant designs and environments, without the need for cumbersome statistical analyses. It is believed that spectrum loading can be considered for the generation of new standardization procedures and design applications. PMID:27161957

  5. Residential Saudi load forecasting using analytical model and Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Al-Harbi, Ahmad Abdulaziz

    In recent years, load forecasting has become one of the main fields of study and research. Short Term Load Forecasting (STLF) is an important part of electrical power system operation and planning. This work investigates the applicability of different approaches; Artificial Neural Networks (ANNs) and hybrid analytical models to forecast residential load in Kingdom of Saudi Arabia (KSA). These two techniques are based on model human modes behavior formulation. These human modes represent social, religious, official occasions and environmental parameters impact. The analysis is carried out on residential areas for three regions in two countries exposed to distinct people activities and weather conditions. The collected data are for Al-Khubar and Yanbu industrial city in KSA, in addition to Seattle, USA to show the validity of the proposed models applied on residential load. For each region, two models are proposed. First model is next hour load forecasting while second model is next day load forecasting. Both models are analyzed using the two techniques. The obtained results for ANN next hour models yield very accurate results for all areas while relatively reasonable results are achieved when using hybrid analytical model. For next day load forecasting, the two approaches yield satisfactory results. Comparative studies were conducted to prove the effectiveness of the models proposed.

  6. Musculoskeletal stiffness changes linearly in response to increasing load during walking gait.

    PubMed

    Caron, Robert R; Lewis, Cara L; Saltzman, Elliot; Wagenaar, Robert C; Holt, Kenneth G

    2015-04-13

    Development of biologically inspired exoskeletons to assist soldiers in carrying load is a rapidly expanding field. Understanding how the body modulates stiffness in response to changing loads may inform the development of these exoskeletons and is the purpose of the present study. Seventeen subjects walked on a treadmill at a constant preferred walking velocity while nine different backpack loading conditions ranging from 12.5% to 40% bodyweight (BW) were introduced in an ascending and then descending order. Kinematic data were collected using Optotrak, a 3D motion analysis system, and used to estimate the position of the center of mass (COM). Two different estimates of stiffness were computed for the stance phase of gait. Both measures of stiffness were positively and linearly related to load magnitudes, with the slopes of the relationships being larger for the descending than the ascending conditions. These results indicate that changes in mechanical stiffness brought about in the musculoskeletal system vary systematically during increases in load to ensure that critical kinematic variables measured in a previous publication remain invariant (Caron et al., 2013). Changes in stiffness and other kinematics measured at the 40% BW condition suggest a boundary in which gait stiffness control limit is reached and a new gait pattern is required. Since soldiers are now carrying up to 96% of body weight, the need for research with even heavier loads is warranted. These findings have implications on the development of exoskeletons to assist in carrying loads. PMID:25678200

  7. VISAR Unfold Analysis of Load Current in MagLIF Experiments

    NASA Astrophysics Data System (ADS)

    Hess, Mark; McBride, Ryan; Martin, Matthew

    2013-10-01

    An accurate prediction of the load current is essential in the performance of MagLIF experiments on the Z-Machine at Sandia. At present, the most accurate diagnostic for measuring load current on the Z-machine is the well-established VISAR technique. The VISAR diagnostic measures the velocity of a thin aluminum foil placed near the load, which is subject to the magnetic pressure produced by the load current, using a laser interferometer. The load current unfold analysis is highly nonlinear due to the equation of state/conductivity models, along with the MHD equations governing the foil. Nevertheless, an accurate load current unfold from the VISAR measurement is possible using an MHD code, in conjunction with an optimization algorithm. We will review the VISAR unfold analysis, and show recent current unfolds of MagLIF experiments in comparison to load current measurements using B-dot probes. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  8. External Load Affects Ground Reaction Force Parameters Non-uniformly during Running in Weightlessness

    NASA Technical Reports Server (NTRS)

    DeWitt, John; Schaffner, Grant; Laughlin, Mitzi; Loehr, James; Hagan, R. Donald

    2004-01-01

    Long-term exposure to microgravity induces detrimefits to the musculcskdetal system (Schneider et al., 1995; LeBlanc et al., 2000). Treadmill exercise is used onboard the International Space Station as an exercise countermeasure to musculoskeletal deconditioning due to spaceflight. During locomotive exercise in weightlessness (0G), crewmembers wear a harness attached to an external loading mechanism (EL). The EL pulls the crewmember toward the treadmill, and provides resistive load during the impact and propulsive phases of gait. The resulting forces may be important in stimulating bone maintenance (Turner, 1998). The EL can be applied via a bungee and carabineer clip configuration attached to the harness and can be manipulated to create varying amounts of load levels during exercise. Ground-based research performed using a vertically mounted treadmill found that peak ground reaction forces (GRF) during running at an EL of less than one body weight (BW) are less than those that occur during running in normal gravity (1G) (Davis et al., 1996). However, it is not known how the GRF are affected by the EL in a true OG environment. Locomotion while suspended may result in biomechanics that differ from free running. The purpose of this investigation was to determine how EL affects peak impact force, peak propulsive force, loading rate, and impulse of the GRF during running in 0G. It was hypothesized that increasing EL would result in increases in each GRF parameter.

  9. High temperature fatigue behavior of a SiC/Ti-24Al-11Nb composite

    NASA Technical Reports Server (NTRS)

    Bartolotta, P. A.; Brindley, P. K.

    1990-01-01

    A series of tension-tension strain- and load-controlled tests were conducted on unidirectional SiC/Ti-24Al-11Nb (at percent) composites at 425 and 815 C. Several regimes of damage were identified using Talrega's concept of fatigue life diagrams. Issues of test technique, test control mode, and definition of failure were also addressed.

  10. Interface considerations in Al2O3/NiAl composite

    NASA Technical Reports Server (NTRS)

    Misra, Ajay K.

    1993-01-01

    The fiber-matrix interface requirements in an Al2O3/NiAl composite were examined from theoretical considerations. Several factors that influence the interface bonding requirements were analyzed. These include: (1) residual stresses due to fiber-matrix coefficient of thermal expansion (CTE) mismatch; (2) matrix cracking stress at room temperature; (3) fracture toughness at room temperature; (4) load transfer from the matrix to the fiber and ultimate tensile strength at the use temperature; and (5) creep resistance at high temperature. A relatively weak fiber-matrix bond, with an interfacial shear strength of approximately 15-20 MPa, might be sufficient for attaining the desired mechanical properties in the fiber direction at the use temperature. A weak fiber-matrix bond is also beneficial for increasing the fracture toughness of the composite at room temperature. In contrast, a strong fiber-matrix bond is required to withstand some of the residual stresses resulting from the fiber-matrix CTE mismatch, which are not likely to be reduced significantly by interface coatings. A relatively strong bond is also beneficial in increasing the matrix cracking stress at room temperature. Various interface coating options to accommodate the conflicting bonding requirements were reviewed. One viable coating option is to incorporate a thick, ductile interface layer well bonded to both the fiber and the matrix.

  11. Numerical studies of multipactor in dielectric-loaded accelerator structures

    NASA Astrophysics Data System (ADS)

    Sinitsyn, Oleksandr; Nusinovich, Gregory; Antonsen, Thomas

    2009-11-01

    Multipactor (MP) is known as the avalanche growth of the number of secondary electrons emitted from a solid surface exposed to an rf electric field under vacuum conditions. MP may occur in various microwave and rf systems such as microwave tubes, rf windows and launchers, accelerating structures, and rf satellite payloads. In this work we present results of MP analysis in dielectric-loaded accelerator (DLA) structures. The starting point of our work was experimental and theoretical studies of DLA structures jointly done by Argonne National Laboratory and Naval Research Laboratory (J. G. Power et al., Phys. Rev. Lett. 92, 164801 (2004); J. G. Power et al., AIP Conf. Proc. 877, 362 (2006)). In the theoretical model developed during those studies the space-charge field due to the total number of particles is taken into account as a parameter. We perform our studies using a self-consistent approach with the help of time-dependent two-dimensional code developed at the University of Maryland (O. V. Sinitsyn et al., Phys. Plasmas 16, 073102 (2009)). Results include analysis of MP evolution at an early stage, detailed studies of individual electron trajectories, analysis of MP onset time under various conditions and comparison of some results with the experimental data.

  12. Ab initio modeling of zincblende AlN layer in Al-AlN-TiN multilayers

    NASA Astrophysics Data System (ADS)

    Yadav, S. K.; Wang, J.; Liu, X.-Y.

    2016-06-01

    An unusual growth mechanism of metastable zincblende AlN thin film by diffusion of nitrogen atoms into Al lattice is established. Using first-principles density functional theory, we studied the possibility of thermodynamic stability of AlN as a zincblende phase due to epitaxial strains and interface effect, which fails to explain the formation of zincblende AlN. We then compared the formation energetics of rocksalt and zincblende AlN in fcc Al through direct diffusion of nitrogen atoms to Al octahedral and tetrahedral interstitials. The formation of a zincblende AlN thin film is determined to be a kinetically driven process, not a thermodynamically driven process.

  13. A Study on a Centralized Under-Voltage Load Shedding Scheme Considering the Load Characteristics

    NASA Astrophysics Data System (ADS)

    Deng, Jiyu; Liu, Junyong

    Under-voltage load shedding is an important measure for maintaining voltage stability.Aiming at the optimal load shedding problem considering the load characteristics,firstly,the traditional under-voltage load shedding scheme based on a static load model may cause the analysis inaccurate is pointed out on the equivalent Thevenin circuit.Then,the dynamic voltage stability margin indicator is derived through local measurement.The derived indicator can reflect the voltage change of the key area in a myopia linear way.Dimensions of the optimal problem will be greatly simplified using this indicator.In the end,mathematical model of the centralized load shedding scheme is built with the indicator considering load characteristics.HSPPSO is introduced to slove the optimal problem.Simulation results on IEEE-39 system show that the proposed scheme display a good adaptability in solving the under-voltage load shedding considering dynamic load characteristics.

  14. Load research manual. Volume 2. Fundamentals of implementing load research procedures

    SciTech Connect

    Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

    1980-11-01

    This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. In Volumes 1 and 2, procedures are suggested for determining data requirements for load research, establishing the size and customer composition of a load survey sample, selecting and using equipment to record customer electricity usage, processing data tapes from the recording equipment, and analyzing the data. Statistical techniques used in customer sampling are discussed in detail. The costs of load research also are estimated, and ongoing load research programs at three utilities are described. The manual includes guides to load research literature and glossaries of load research and statistical terms.

  15. A novel dual-frequency loading system for studying mechanobiology of load-bearing tissue.

    PubMed

    Zhang, Chunqiu; Qiu, Lulu; Gao, Lilan; Guan, Yinjie; Xu, Qiang; Zhang, Xizheng; Chen, Qian

    2016-12-01

    In mechanobiological research, an appropriate loading system is an essential tool to mimic mechanical signals in a native environment. To achieve this goal, we have developed a novel loading system capable of applying dual-frequency loading including both a low-frequency high-amplitude loading and a high-frequency low-amplitude loading, according to the mechanical conditions experienced by bone and articular cartilage tissues. The low-frequency high-amplitude loading embodies the main force from muscular contractions and/or reaction forces while the high-frequency low-amplitude loading represents an assistant force from small muscles, ligaments and/or other tissue in order to maintain body posture during human activities. Therefore, such dual frequency loading system may reflect the natural characteristics of complex mechanical load on bone or articular cartilage than the single frequency loading often applied during current mechanobiological experiments. The dual-frequency loading system is validated by experimental tests using precision miniature plane-mirror interferometers. The dual-frequency loading results in significantly more solute transport in articular cartilage than that of the low-frequency high-amplitude loading regiment alone, as determined by quantitative fluorescence microscopy of tracer distribution in articular cartilage. Thus, the loading system can provide a new method to mimic mechanical environment in bone and cartilage, thereby revealing the in vivo mechanisms of mechanosensation, mechanotransduction and mass-transport, and improving mechanical conditioning of cartilage and/or bone constructs for tissue engineering. PMID:27612712

  16. A novel dual-frequency loading system for studying mechanobiology of load-bearing tissue.

    PubMed

    Zhang, Chunqiu; Qiu, Lulu; Gao, Lilan; Guan, Yinjie; Xu, Qiang; Zhang, Xizheng; Chen, Qian

    2016-12-01

    In mechanobiological research, an appropriate loading system is an essential tool to mimic mechanical signals in a native environment. To achieve this goal, we have developed a novel loading system capable of applying dual-frequency loading including both a low-frequency high-amplitude loading and a high-frequency low-amplitude loading, according to the mechanical conditions experienced by bone and articular cartilage tissues. The low-frequency high-amplitude loading embodies the main force from muscular contractions and/or reaction forces while the high-frequency low-amplitude loading represents an assistant force from small muscles, ligaments and/or other tissue in order to maintain body posture during human activities. Therefore, such dual frequency loading system may reflect the natural characteristics of complex mechanical load on bone or articular cartilage than the single frequency loading often applied during current mechanobiological experiments. The dual-frequency loading system is validated by experimental tests using precision miniature plane-mirror interferometers. The dual-frequency loading results in significantly more solute transport in articular cartilage than that of the low-frequency high-amplitude loading regiment alone, as determined by quantitative fluorescence microscopy of tracer distribution in articular cartilage. Thus, the loading system can provide a new method to mimic mechanical environment in bone and cartilage, thereby revealing the in vivo mechanisms of mechanosensation, mechanotransduction and mass-transport, and improving mechanical conditioning of cartilage and/or bone constructs for tissue engineering.

  17. Physical work load in physical education teachers.

    PubMed

    Sandmark, H; Wiktorin, C; Hogstedt, C; Klenell-Hatschek, E K; Vingard, E

    1999-10-01

    The main objective was to measure and quantify exposure to physical work load in physical education teachers. A further aim was to establish the reproducibility of a three-week test-retest interval of self-reported physical load and to evaluate the agreement between registered and self-rated physical load. Thirty teachers, both female and male, volunteered to participate in the study. The physical load on the lower extremities, as well as the back and the cardio-vascular strain was recorded during one working day. The results indicate that the physical work load in this occupational group is considerable due to the load on the lower extremities. The demands of the cardio-vascular system are also relatively high in comparison to other occupational groups. The teachers could assess their activity quite well regarding heavy lifting and time spent sitting.

  18. Combined loading criterial influence on structural performance

    NASA Technical Reports Server (NTRS)

    Kuchta, B. J.; Sealey, D. M.; Howell, L. J.

    1972-01-01

    An investigation was conducted to determine the influence of combined loading criteria on the space shuttle structural performance. The study consisted of four primary phases: Phase (1) The determination of the sensitivity of structural weight to various loading parameters associated with the space shuttle. Phase (2) The determination of the sensitivity of structural weight to various levels of loading parameter variability and probability. Phase (3) The determination of shuttle mission loading parameters variability and probability as a function of design evolution and the identification of those loading parameters where inadequate data exists. Phase (4) The determination of rational methods of combining both deterministic time varying and probabilistic loading parameters to provide realistic design criteria. The study results are presented.

  19. RTLS entry load relief parameter optimization

    NASA Technical Reports Server (NTRS)

    Crull, T. J.

    1975-01-01

    The results are presented of a study of a candidate load relief control law for use during the pullup phase of Return-to-Launch-Site (RTLS) abort entries. The control law parameters and cycle time which optimized performance of the normal load factor limiting phase (load relief phase) of an RTLS entry are examined. A set of control law gains, a smoothing parameter, and a normal force coefficient curve fit are established which resulted in good load relief performance considering the possible aerodynamic coefficient uncertainties defined. Also, the examination of various guidance cycle times revealed improved load relief performance with decreasing cycle time. A .5 second cycle provided smooth and adequate load relief in the presence of all the aerodynamic uncertainties examined.

  20. Grid scheduling divisible loads from two sources

    SciTech Connect

    Moges, M.A.; Yu, D.; Robertazzi, T.

    2009-07-10

    To date closed form solutions for optimal finish time and job allocation are largely obtained only for network topologies with a single load originating (root) processor. However in large-scale data intensive problems with geographically distributed resources, load is generated from multiple sources. This paper introduces a new divisible load scheduling strategy for single level tree networks with two load originating processors. Solutions for an optimal allocation of fractions of load to nodes in single level tree networks are obtained via linear programming. A unique scheduling strategy that allows one to obtain closed form solutions for the optimal finish time and load allocation for each processor in the network is also presented. The tradeoff between linear programming and closed form solutions in terms of underlying assumptions is examined. Finally, a performance evaluation of a two source homogeneous single level tree network with concurrent communication strategy is presented.

  1. NASA Dryden Flight Loads Research Facility

    NASA Technical Reports Server (NTRS)

    Sefic, W. J.

    1981-01-01

    The Dryden Flight Loads Research Facility (NASA) and the associated equipment for simulating the loading and heating of aircraft or their components are described. Particular emphasis is placed on various fail-safe devices which are built into the equipment to minimize the possibility of damage to flight vehicles. The equipment described includes the ground vibration and moment of inertia equipment, the data acquisition system, and the instrumentation available in the facility for measuring load, position, strain, temperature, and acceleration.

  2. 1991 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1991-12-01

    This study establishes the Bonneville Power Administration's (BPA) planning basis for supplying electricity to BPA customers. The Loads and Resources Study is presented in three documents: (1) this summary of federal system and Pacific Northwest region loads and resources; (2) a technical appendix detailing forecasted Pacific Northwest economic trends and loads, and (3) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. This analysis updates our 1990 study. BPS's long-range planning incorporates resource availability with a range of forecasted electrical consumption. The forecasted future electrical demands-firm loads--are subtracted from the projected capability of existing resources to determine whether BPA and the region will be surplus or deficit. If resources are greater than loads in any particular year or month, there is a surplus of energy and/or capacity, which BPA can sell to increase revenues. Conversely, if firm loads exceed available resources, there is a deficit of energy and/or capacity, then additional conservation, contract purchases, or generating resources will be needed to meet load growth. This study analyzes the Pacific Northwest's projected loads and available generating resources in two parts: (1) the loads and resources of the federal system, for which BPA is the marketing agency; and (2) the larger Pacific Northwest regional profile, which includes loads and resources in addition to the federal system. This study presents the federal system and regional analyses for five load forecasts: high, medium-high, medium, medium-low, and low. This analysis projects the yearly average energy consumption and resource availability for 1992- 2012.

  3. A no-load RF calorimeter

    NASA Technical Reports Server (NTRS)

    Chernoff, R. C.

    1975-01-01

    The described device can be used to measure the output of any dc powered RF source. No dummy load is required for the measurements. The device is, therefore, called the 'no-load calorimeter' (NLC). The NLC measures the power actually fed to the antenna or another useful load. It is believed that the NLC can compete successfully with directional coupler type systems in measuring the output of high-power RF sources.

  4. Dual-band reactively loaded microstrip antenna

    NASA Technical Reports Server (NTRS)

    Richards, W. F.; Long, S. A.; Davidson, S. E.

    1985-01-01

    A previously derived theory is applied to a microstrip antenna with a reactive load to produce a dual-band radiator. A model consisting of a rectangular patch radiator loaded with a variable length short-circuited coaxial stub was investigated experimentally. Comparisons of theoretical predictions and experimental data are made for the impedance and resonant frequencies as a function of the position of the load, the length of the stub, and the characteristic impedance of the stub.

  5. The Evidence for Symplastic Phloem Loading 1

    PubMed Central

    Turgeon, Robert; Beebe, Dwight U.

    1991-01-01

    Experimental protocols used to study the route(s) of phloem loading in source leaves are evaluated; they include the analysis of plasmodesmatal ultrastructure and distribution, mobile compounds in the free space, loading patterns of exogenous sugars, the site of sugar synthesis, and dye coupling. All these methods have drawbacks. There are indications that some plants, especially those that translocate the raffinose series of sugars, load by a symplastic (through plasmodesmata) pathway, but the evidence is weak. PMID:16668192

  6. 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

  7. Automated load management for spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1987-01-01

    An account is given of the results of a study undertaken by NASA's Marshall Space Flight Center to design and implement the load management techniques for autonomous spacecraft power systems, such as the Autonomously Managed Power System Test Facility. Attention is given to four load-management criteria, which encompass power bus balancing on multichannel power systems, energy balancing in such systems, power quality matching of loads to buses, and contingency load shedding/adding. Full implementation of these criteria calls for the addition of a second power channel.

  8. Plutonium Immobilization Can Loading Conceptual Design

    SciTech Connect

    Kriikku, E.

    1999-05-13

    'The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

  9. Multiplexer/Demultiplexer Loading Tool (MDMLT)

    NASA Technical Reports Server (NTRS)

    Brewer, Lenox Allen; Hale, Elizabeth; Martella, Robert; Gyorfi, Ryan

    2012-01-01

    The purpose of the MDMLT is to improve the reliability and speed of loading multiplexers/demultiplexers (MDMs) in the Software Development and Integration Laboratory (SDIL) by automating the configuration management (CM) of the loads in the MDMs, automating the loading procedure, and providing the capability to load multiple or all MDMs concurrently. This loading may be accomplished in parallel, or single MDMs (remote). The MDMLT is a Web-based tool that is capable of loading the entire International Space Station (ISS) MDM configuration in parallel. It is able to load Flight Equivalent Units (FEUs), enhanced, standard, and prototype MDMs as well as both EEPROM (Electrically Erasable Programmable Read-Only Memory) and SSMMU (Solid State Mass Memory Unit) (MASS Memory). This software has extensive configuration management to track loading history, and the performance improvement means of loading the entire ISS MDM configuration of 49 MDMs in approximately 30 minutes, as opposed to 36 hours, which is what it took previously utilizing the flight method of S-Band uplink. The laptop version recently added to the MDMLT suite allows remote lab loading with the CM of information entered into a common database when it is reconnected to the network. This allows the program to reconfigure the test rigs quickly between shifts, allowing the lab to support a variety of onboard configurations during a single day, based on upcoming or current missions. The MDMLT Computer Software Configuration Item (CSCI) supports a Web-based command and control interface to the user. An interface to the SDIL File Transfer Protocol (FTP) server is supported to import Integrated Flight Loads (IFLs) and Internal Product Release Notes (IPRNs) into the database. An interface to the Monitor and Control System (MCS) is supported to control the power state, and to enable or disable the debug port of the MDMs to be loaded. Two direct interfaces to the MDM are supported: a serial interface (debug port) to

  10. The emergence of load-oriented sterilization.

    PubMed

    Kolstad, R A

    1994-01-01

    Achieving maximum equipment sterilization is critical. Factors that contribute to sterilization efficiency are covered, including sterilization accuracy level, chamber loading and biological indicators. PMID:8031354

  11. The Load Dependence of Kinesin's Mechanical Cycle

    NASA Astrophysics Data System (ADS)

    Coppin, Chris M.; Pierce, Daniel W.; Hsu, Long; Vale, Ronald D.

    1997-08-01

    Kinesin is a dimeric motor protein that transports organelles in a stepwise manner toward the plus-end of microtubules by converting the energy of ATP hydrolysis into mechanical work. External forces can influence the behavior of kinesin, and force-velocity curves have shown that the motor will slow down and eventually stall under opposing loads of ≈ 5 pN. Using an in vitro motility assay in conjunction with a high-resolution optical trapping microscope, we have examined the behavior of individual kinesin molecules under two previously unexplored loading regimes: super-stall loads (>5 pN) and forward (plus-end directed) loads. Whereas some theories of kinesin function predict a reversal of directionality under high loads, we found that kinesin does not walk backwards under loads of up to 13 pN, probably because of an irreversible transition in the mechanical cycle. We also found that this cycle can be significantly accelerated by forward loads under a wide range of ATP concentrations. Finally, we noted an increase in kinesin's rate of dissociation from the microtubule with increasing load, which is consistent with a load dependent partitioning between two recently described kinetic pathways: a coordinated-head pathway (which leads to stepping) and an independent-head pathway (which is static).

  12. High-Power Testing of 11.424-GHz Dielectric-Loaded Accelerating Structures

    NASA Astrophysics Data System (ADS)

    Gold, Steven; Gai, Wei

    2001-10-01

    Argonne National Laboratory has previously described the design, construction, and bench testing of an X-band traveling-wave accelerating structure loaded with a permittivity=20 dielectric (P. Zou et al., Rev. Sci. Instrum. 71, 2301, 2000.). We describe a new program to build a test accelerator using this structure. The accelerator will be powered by the high-power 11.424-GHz radiation from the magnicon facility at the Naval Research Laboratory ( O.A. Nezhevenko et al., Proc. PAC 2001, in press). The magnicon is expected to provide up to 30 MW from each of two WR-90 output waveguide arms in pulses of up to 1 microsecond duration, permitting tests up to a gradient of 40 MV/m. Still higher power pulses (100-500 MW) may be available at the output of an active pulse compressor driven by the magnicon ( A.L. Vikharev et al., Proc. 9th Workshop on Advanced Accelerator Concepts.).

  13. Mechanical and Morphological Properties of Polypropylene/Nano α-Al2O3 Composites

    PubMed Central

    Mirjalili, F.; Chuah, L.; Salahi, E.

    2014-01-01

    A nanocomposite containing polypropylene (PP) and nano α-Al2O3 particles was prepared using a Haake internal mixer. Mechanical tests, such as tensile and flexural tests, showed that mechanical properties of the composite were enhanced by addition of nano α-Al2O3 particles and dispersant agent to the polymer. Tensile strength was approximately ∼16% higher than pure PP by increasing the nano α-Al2O3 loading from 1 to 4 wt% into the PP matrix. The results of flexural analysis indicated that the maximum values of flexural strength and flexural modulus for nanocomposite without dispersant were 50.5 and 1954 MPa and for nanocomposite with dispersant were 55.88 MPa and 2818 MPa, respectively. However, higher concentration of nano α-Al2O3 loading resulted in reduction of those mechanical properties that could be due to agglomeration of nano α-Al2O3 particles. Transmission and scanning electron microscopic observations of the nanocomposites also showed that fracture surface became rougher by increasing the content of filler loading from 1 to 4% wt. PMID:24688421

  14. Residual stress analysis on tensile MMC specimens after loading/unloading tests in several conditions

    NASA Astrophysics Data System (ADS)

    Giuliani, Alessandra; Albertini, Gianni; Manescu, Adrian

    2004-07-01

    Residual stresses have been investigated in samples made of AA6061+22% Al2O3 in order to correlate microstructural characteristics with mechanical performances. In particular, the possible occurrence of a brittle fracture induced by an excessive load transfer from the matrix to the reinforcement was investigated. To this end, macrostresses and microstresses were analysed. A neutron diffraction test on 12 specimens submitted to several loading/unloading conditions at different temperatures was performed. These measurements aimed to establish the optimal temperature for the initial extruded billet in pre-heating stage, before forging the final wheel hub.

  15. Measuring training load in sports.

    PubMed

    Lambert, Michael Ian; Borresen, Jill

    2010-09-01

    The principle of training can be reduced to a simple "dose-response" relationship. The "response" in this relationship can be measured as a change in performance or the adaptation of a physiological system. The "dose" of training, or physiological stress associated with the training load, is more difficult to measure as there is no absolute "gold standard" which can be used in the field, making it difficult to validate procedures. Attempts have been made to use heart rate as a marker of intensity during training, but the theoretical attractiveness of this method is not supported by the accuracy and the practicality of using this method during training or competition. The session RPE, based on the product of training duration and perceived intensity is more practical and can be used in a variety of sports. However, the score depends on a subjective assessment, and the intersubject comparisons may be inaccurate. The demands of different sports vary and therefore the methods of assessing training need to vary accordingly. The time has come to reach consensus on assessing training accurately in different sports. There is a precedent for this consensus approach with scientists having already done so for the assessment of physical activity, and for defining injuries in rugby, football and cricket. Standardizing these methods has resulted in the quality of research in these areas increasing exponentially.

  16. Pallet loading dust control system

    SciTech Connect

    Cecala, A.B.; Covelli, A.

    1987-01-01

    This paper presents a pallet loading dust control system designed to lower the dust exposure of workers during the bag stacking process at mineral processing facilities. The system makes bag stacking much easier because the pallet height remains constant throughout the entire bag stacking cycle through the use of a hydraulic lift table. The system uses a push-pull ventilation technique to capture the dust generated during bag stacking. A low-volume, high-velocity blower system operating at approximately 150 cfm blows a stream of air over the top layer of bags on the pallet. The blower system is composed of two 3-in air jets (approximately 1,200-ft/min velocity) directed toward an exhaust system on the opposite side of the pallet. As these air jets travel across the pallet, they entrain the dust generated during bag stacking. The exhaust ventilation system pulls approximately 2,500 cfm of air and dust through the exhaust hood. This exhaust air can then be dumped into a bag-house ventilation system, or filtered before being discharged outside the mill.

  17. Storage tanks under earthquake loading

    SciTech Connect

    Rammerstorfer, F.G.; Scharf, K. ); Fisher, F.D. )

    1990-11-01

    This is a state-of-the-art review of various treatments of earthquake loaded liquid filled shells by the methods of earthquake engineering, fluid dynamics, structural and soil dynamics, as well as the theory of stability and computational mechanics. Different types of tanks and different possibilities of tank failure will be discussed. The authors will emphasize cylindrical above-ground liquid storage tanks with vertical axis. But many of the treatments are also valid for other tank configurations. For the calculation of the dynamically activated pressure due to an earthquake a fluid-structure-soil interaction problem must be solved. The review will describe the methods, proposed by different authors, to solve this interaction problem. To study the dynamic behavior of liquid storage tanks, one must distinguish between anchored and unanchored tanks. In the case of an anchored tank, the tank bottom edge is fixed to the foundation. If the tank is unanchored, partial lifting of the tank's bottom may occur, and a strongly nonlinear problem has to be solved. They will compare the various analytical and numerical models applicable to this problem, in combination with experimental data. An essential aim of this review is to give a summary of methods applicable as tools for an earthquake resistant design, which can be used by an engineer engaged in the construction of liquid storage tanks.

  18. System and method employing a self-organizing map load feature database to identify electric load types of different electric loads

    SciTech Connect

    Lu, Bin; Harley, Ronald G.; Du, Liang; Yang, Yi; Sharma, Santosh K.; Zambare, Prachi; Madane, Mayura A.

    2014-06-17

    A method identifies electric load types of a plurality of different electric loads. The method includes providing a self-organizing map load feature database of a plurality of different electric load types and a plurality of neurons, each of the load types corresponding to a number of the neurons; employing a weight vector for each of the neurons; sensing a voltage signal and a current signal for each of the loads; determining a load feature vector including at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the loads; and identifying by a processor one of the load types by relating the load feature vector to the neurons of the database by identifying the weight vector of one of the neurons corresponding to the one of the load types that is a minimal distance to the load feature vector.

  19. Experimental and numerical investigation of a RC wall loaded by snow-like avalanche pressure signal

    NASA Astrophysics Data System (ADS)

    Ousset, Isabelle; Bertrand, David; Brun, Michaël; Limam, Ali; Naaïm, Mohamed

    2013-04-01

    Nowadays, civil engineering structures exposed to snow avalanches are mostly designed considering static loadings involving large safety factors. These latters highlight the lack of knowledge about the effects of the loading generated by a snow flow, and generally lead to oversize the civil structure. Indeed, the transient nature of the loading signal and also the composition of the snow flow can generate dynamic phenomena which cannot be taken into account considering only static loadings. The case of the avalanche of the Taconnaz (France), which occurred in 1999 and where important parts of the defense structure were destroyed, showed that static design approaches can lead to underestimate the potential effect of the snow flow. Thus, in order to give some new insights about this issue, the effect of the temporal variations of the snow loading on the mechanical behavior of an idealized defense structure is investigated. Therefore, a reinforced concrete (RC) wall with a L-like shape has been considered which is supposed to represent a part of the defense structure situated in Taconnaz. Static pushover tests, carried out in laboratory conditions on 1/6 scale physical model of the RC structure, allowed obtaining the capacity of the tested structure (Berthet-Rambaud et al. (2007)). Finite Element (FE) models have been developed and calibrated from the previous experimental data. The FE approach allows simulating the dynamic mechanical response of the structure. The effect of the transient nature of the loading of the avalanche has been explored applying out-of-plan dynamic loadings on the RC wall. In order to be as close as possible of a "field" snow avalanche, the imposed time evolution of the loading has been generated from in situ measurements recorded at the French experimental site "le col du Lautaret" (Thibert et al. (2008)). The RC mechanical behaviour has been described by four nonlinear constitutive laws. The four behaviour laws are compared and analyzed for

  20. CONTAINMENT EVALUATION OF BREACHED AL-SNF FOR CASK TRANSPORT

    SciTech Connect

    Vinson, D. W.; Sindelar, R. L.; Iyer, N. C.

    2005-11-07

    Aluminum-based spent nuclear fuel (Al-SNF) from foreign and domestic research reactors (FRR/DRR) is being shipped to the Savannah River Site. To enter the U.S., the cask with loaded fuel must be certified to comply with the requirements in the Title 10 of the U.S. Code of Federal Regulations, Part 71. The requirements include demonstration of containment of the cask with its contents under normal and accident conditions. Al-SNF is subject to corrosion degradation in water storage, and many of the fuel assemblies are ''failed'' or have through-clad damage. A methodology has been developed with technical bases to show that Al-SNF with cladding breaches can be directly transported in standard casks and maintained within the allowable release rates. The approach to evaluate the limiting allowable leakage rate, L{sub R}, for a cask with breached Al-SNF for comparison to its test leakage rate could be extended to other nuclear material systems. The approach for containment analysis of Al-SNF follows calculations for commercial spent fuel as provided in NUREG/CR-6487 that adopts ANSI N14.5 as a methodology for containment analysis. The material-specific features and characteristics of damaged Al-SNF (fuel materials, fabrication techniques, microstructure, radionuclide inventory, and vapor corrosion rates) that were derived from literature sources and/or developed in laboratory testing are applied to generate the four containment source terms that yield four separate cask cavity activity densities; namely, those from fines; gaseous fission product species; volatile fission product species; and fuel assembly crud. The activity values, A{sub 2}, are developed per the guidance of 10CFR71. The analysis is performed parametrically to evaluate maximum number of breached assemblies and exposed fuel area for a proposed shipment in a cask with a test leakage rate.

  1. [Effects of load and loading time on fracture toughness with indentation method].

    PubMed

    Okada, T; Shinya, A; Yokozuka, S

    1990-10-01

    For clinical application of ceramics such as porcelains that are frequently used as crown restoration materials, it is important to quantitatively evaluate and determine brittleness. This quality is expressed as a fracture toughness value, KIC, but no distinct method for its determination has yet been established. In order to standardize conditions for the determination of KIC by the indentation method, effects of indentation load and loading time on KIC of calcium phosphate crystalline ceramics (CP) were studied at various Vickers indentation loads and various loading times in CP plate-like segments. Furthermore, plate-like segments of each of CP, apatite (AP), mica-beta-spodumene (MIS) and mica (MIC) groups were subjected to experiment at various indentation loads at a fixed loading time to study the effects of indentation load on KIC in four kinds of Castable Ceramics. The results are summarized as follows: 1) The Vickers hardness degree of CP was decreased with an increase in indentation load and loading time, reaching the maximum value (499Hv) at 1kgf of indentation load and 5s of loading time. 2) The value of half of the crack length of CP was increased with an increase in indentation load and loading time, reaching a maximum (530 microns) at 20kgf of indentation load and 30s of loading time. 3) KIC of CP reached the maximum value (2.78MNm-3/2) at 5kgf of indentation load and 5s of loading time, and the minimum (1.52MNm-3/2) at 20kgf of indentation load and 30s of loading time. 4) Optimal experimental conditions for KIC of CP determined by indentation method were 5kgf or 10kgf of indentation load and 15s of loading time. 5) KIC values (MNm-3/2) determined at 5kgf of indentation load and 15s of loading time for CP, AP, MIS and MI were 2.27, 0.95, 1.82 and 1.81, respectively. 6) The course of cracks due to indentation force showed a linear pattern of intra-granular fracture. 7) The cracks were revealed to show median cracks by fractography.

  2. An evaluation of critical loads of soil acidity in areas of high sea salt deposition.

    PubMed

    Reynolds, B

    2000-05-15

    The empirical and mass balance approaches to setting critical loads of acidity for mineral soils have been evaluated using field data from forest sites in Wales. Using the Simple Mass Balance Equation (SMBE) with Sitka spruce as the biological target, critical loads ranged between 2.3 and 9.8 keq H+ ha(-1) year(-1) compared to mapped empirical critical loads which ranged between 0.2 and 0.5 keq H+ ha(-1) year(-1). At all sites the empirical critical load was exceeded with respect to deposited sulfur acidity. There were no exceeded sites for the SMBE critical loads. The big differences between the two methods arise from the large ANC leaching term in the SMBE model which is determined by the relatively low (Ca + Mg + K)/Al(crit) ratio for Sitka spruce, compared to other conifers, and the influence of the large deposition of sea salt base cations. The low value of the (Ca + Mg + K)/Al(crit) ratio for Sitka spruce implies that it is tolerant of very acidic soil conditions, however, the ratio is based on the results of only one solution culture study and may thus be uncertain under field conditions. Large sea salt base cation deposition directly influences SMBE critical loads because the predicted soil water base cation concentrations permit large concentrations of hydrogen ions and aluminium (low ANC values) before the critical chemical limit is transgressed. Where weathering rates are low, critical ANC leaching (ANC(lecrit)) becomes the dominant term in the SMBE, with the counter intuitive result that the critical load becomes a linear function of sea salt base cation deposition. Thus the current formulation of the SMBE may not be appropriate for low weathering rate areas receiving large amounts of sea salt base cation deposition.

  3. High solids loading for water-based tape casting

    NASA Astrophysics Data System (ADS)

    Suwannasiri, Thitima

    71-73 vol% could be reached in an aqueous system for the size-modified powder, before binder addition. An emulsion binder (Duramaxsp{TM} B-1001) aided the reduction in viscosity of the high solids loading suspension, while the soluble binder aggravated the agglomeration and drastically raised the viscosity. The emulsion binder used also had high polymer content and, therefore, less water. The final solids loadings obtained were 55.7 vol% for A-16SG and 63 vol% for mixed A-152SG and A-16SG powder. The drying time was reduced by one third for the 63 vol% formulation compared to the 55.7 vol% formulation. Water-based tape casting of A1N was possible in a buffer solution. Polyacrylic acid, PAA (M.W. 1800), aided dispersion and also minimized hydrolysis of A1N in water. Poly(vinyl pyrrolidone), PVP (M.W. 160,000), gave a lower viscosity to suspension compared to poly(vinyl alcohol) and cellulose ether, and had less bubble formation. The suspension could be processed for more than 72 h without degradation. With optimization of dispersant and binder, a high solids loading formulation of 52 vol% could be obtained. When the organic components were burned out in the air, AlN with 3wt% Ysb2Osb3 could be sintered at 1800sp°C for 1 h without degradation. The thermal conductivity was up to 153 W/m.K.

  4. The epidemiology of ALS: a conspiracy of genes, environment and time.

    PubMed

    Al-Chalabi, Ammar; Hardiman, Orla

    2013-11-01

    Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive neurodegenerative disease of motor neurons, resulting in worsening weakness of voluntary muscles until death from respiratory failure occurs after about 3 years. Although great advances have been made in our understanding of the genetic causes of ALS, the contribution of environmental factors has been more difficult to assess. Large-scale studies of the clinical patterns of ALS, individual histories preceding the onset of ALS, and the rates of ALS in different populations and groups have led to improved patient care, but have not yet revealed a replicable, definitive environmental risk factor. In this Review, we outline what is currently known of the environmental and genetic epidemiology of ALS, describe the current state of the art with respect to the different types of ALS, and explore whether ALS should be considered a single disease or a syndrome. We examine the relationship between genetic and environmental risk factors, and propose a disease model in which ALS is considered to be the result of environmental risks and time acting on a pre-existing genetic load, followed by an automatic, self-perpetuating decline to death. PMID:24126629

  5. Evaluation of Ti-48Al-2Cr-2Nb Under Fretting Conditions

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Lerch, Bradley A.; Draper, Susan L.; Raj, Sai V.

    2001-01-01

    The fretting behavior of Ti-48Al-2Cr-2Nb (y-TiAl) in contact with the nickel-base superalloy 718 was examined in air at temperatures from 296 to 823 K (23 to 550 C). The interfacial adhesive bonds between Ti-48Al-2Cr-2Nb and superalloy 718 were generally stronger than the cohesive bonds within Ti-48Al-2Cr-2Nb. The failed Ti-48Al-2Cr-2Nb debris subsequently transferred to the superalloy 718. In reference experiments conducted with Ti-6Al-4V against superalloy 718 under identical fretting conditions, the degree of transfer was greater for Ti-6A1-4V than for Ti-48Al-2Cr-2Nb. Wear of Ti-48Al-2Cr-2Nb generally decreased with increasing fretting frequency. The increasing rate of oxidation at elevated temperatures led to a drop in wear at 473 K. However, fretting wear increased as the temperature was increased from 473 to 823 K. At 723 and 823 K, oxide film disruption generated cracks, loose wear debris, and pits on the Ti-48Al-2Cr-2Nb wear surface. Both increasing slip amplitude and increasing load tended to produce more metallic wear debris, causing severe abrasive wear in the contacting metals.

  6. Load Balancing Using Time Series Analysis for Soft Real Time Systems with Statistically Periodic Loads

    NASA Technical Reports Server (NTRS)

    Hailperin, Max

    1993-01-01

    This thesis provides design and analysis of techniques for global load balancing on ensemble architectures running soft-real-time object-oriented applications with statistically periodic loads. It focuses on estimating the instantaneous average load over all the processing elements. The major contribution is the use of explicit stochastic process models for both the loading and the averaging itself. These models are exploited via statistical time-series analysis and Bayesian inference to provide improved average load estimates, and thus to facilitate global load balancing. This thesis explains the distributed algorithms used and provides some optimality results. It also describes the algorithms' implementation and gives performance results from simulation. These results show that our techniques allow more accurate estimation of the global system load ing, resulting in fewer object migration than local methods. Our method is shown to provide superior performance, relative not only to static load-balancing schemes but also to many adaptive methods.

  7. First micromachined silicon load cell for loads up to 1000 kg

    NASA Astrophysics Data System (ADS)

    Wensink, Henk; de Boer, Meint J.; Wiegerink, Remeo J.; Zwijze, Robert A.; Elwenspoek, Miko C.

    1998-09-01

    In this paper, a bulk micromachined silicon load cell is presented, designed for loads up to 1000 kg. ANSYS simulations were used to determine the load cell dimensions and strain gauge positions. The load cell consists of two parts, which are bonded to each other using Low Temperature Silicon Direct Bonding processes. To isolate the membrane with the sensors from lateral displacements within the load cell (e.g. expansion due to compression) thin silicon springs are incorporated in the design. To make these springs, a cryogenic RIE process with a high selectivity for resist was developed. A special housing was developed to apply a homogeneous load to the load cell. The sensor was successfully tested with loads up to 1000 kg using poly- silicon strain gauges.

  8. Andalusian astronomy: al-Zij al-Muqtabis of Ibn al-Kammâd.

    NASA Astrophysics Data System (ADS)

    Chabás, J.; Goldstein, B. R.

    1994-12-01

    In the twelfth century the Arabic astronomer Ibn al-Kammâd, living in Islamic Spain, composed three sets of astronomical tables, called "zijes". The zijes were largely based on the work of predecessors, going back to Ptolemy on the one hand, and Hindu astronomers on the other. None of his zijes survived in the original Arabic, but a Latin manuscript contains a translation of an apparently complete zij, the "al-Zij al-Muqtabis". This paper examines the body of astronomical knowledge contained in this zij. Specifically, it is shown that one can gain valuable information on the solar theory of the Islamic astronomers from this translation. Furthermore, the theory of lunar and solar eclipses in the work is analyzed, and tables of mean planetary and solar motions are discussed. In addition, tables for the motion of the vernal equinox, star tables, and several topics of Islamic spherical astronomy are examined.

  9. Microstructure Evolution and Mechanical Properties of Al/Al-Mg/Al composite sheet metals

    NASA Astrophysics Data System (ADS)

    Cho, Jaehyung; Kim, Su-Hyeon; Kim, Hyoung-Wook; Lim, Cha-Yong; Kim, Eun-Young; Choi, Shi-Hoon

    2011-08-01

    Two different types of aluminum alloys of AA1050 and AA5182 were used to manufacture Al/Al-Mg/Al composite sheet metals by roll bonding technology at room temperature. The composite sheet metals were annealed at 400 °C and carried out uniaxial tension tests to investigate mechanical properties. Macroscopic mechanical properties are strongly dependent on the volume (or thickness) fraction of two component layers. Microstructure and texture evolution were also investigated during roll bonding process. The AA1050 sheets located in the outer layer mainly consist of shear texture components and the AA5182 sheet located in the center layer consists of plane strain texture components. With differential speeds of the top and bottom rolls, roll bonding was also carried out. Elongation along the RD and TD was improved at a speed difference of approximately 10%-20%.

  10. Strategies for Controlling Plug Loads. A Tool for Reducing Plug Loads in Commercial Buildings

    SciTech Connect

    Torcellini, Paul; Bonnema, Eric; Sheppy, Michael; Pless, Shanti

    2015-09-01

    Plug loads are often not considered as part of the energy savings measures in Commercial Buildings; however, they can account for up to 50% of the energy used in the building. These loads are numerous and often scattered throughout a building. Some of these loads are purchased by the owner and some designed into the building or the tenant finishes for a space. This document provides a strategy and a tool for minimizing these loads.

  11. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  12. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  13. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  14. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  15. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  16. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  17. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  18. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  19. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  20. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means for... maximum external load for which authorization is requested. It must be shown by analysis, test, or both...) Provides a dual actuation device for the primary quick release subsystem, and (ii) Provides a separate...

  1. 14 CFR 23.427 - Unsymmetrical loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... combination with the loads prescribed for the flight conditions set forth in §§ 23.421 through 23.425. (b) In the absence of more rational data for airplanes that are conventional in regard to location of engines... loading from the symmetrical flight conditions may be assumed on the surface on one side of the plane...

  2. 10 CFR 434.512 - Internal loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Internal loads. 434.512 Section 434.512 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Energy Cost Compliance Alternative § 434.512 Internal loads. 512.1The...

  3. 10 CFR 434.512 - Internal loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Internal loads. 434.512 Section 434.512 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Energy Cost Compliance Alternative § 434.512 Internal loads. 512.1The...

  4. 10 CFR 434.512 - Internal loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Internal loads. 434.512 Section 434.512 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Energy Cost Compliance Alternative § 434.512 Internal loads. 512.1The...

  5. 10 CFR 434.512 - Internal loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Internal loads. 434.512 Section 434.512 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Energy Cost Compliance Alternative § 434.512 Internal loads. 512.1The...

  6. 10 CFR 434.512 - Internal loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Internal loads. 434.512 Section 434.512 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Energy Cost Compliance Alternative § 434.512 Internal loads. 512.1 The...

  7. 46 CFR 153.806 - Loading information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Loading information. 153.806 Section 153.806 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING... Inspection § 153.806 Loading information. Each tankship must have a manual containing information...

  8. A review of research in rotor loads

    NASA Technical Reports Server (NTRS)

    Bousman, William G.; Mantay, Wayne R.

    1988-01-01

    The research accomplished in the area of rotor loads over the last 13 to 14 years is reviewed. The start of the period examined is defined by the 1973 AGARD Milan conference and the 1974 hypothetical rotor comparison. The major emphasis of the review is research performed by the U.S. Army and NASA at their laboratories and/or by the industry under government contract. For the purpose of this review, two main topics are addressed: rotor loads prediction and means of rotor loads reduction. A limited discussion of research in gust loads and maneuver loads is included. In the area of rotor loads predictions, the major problem areas are reviewed including dynamic stall, wake induced flows, blade tip effects, fuselage induced effects, blade structural modeling, hub impedance, and solution methods. It is concluded that the capability to predict rotor loads has not significantly improved in this time frame. Future progress will require more extensive correlation of measurements and predictions to better understand the causes of the problems, and a recognition that differences between theory and measurement have multiple sources, yet must be treated as a whole. There is a need for high-quality data to support future research in rotor loads, but the resulting data base must not be seen as an end in itself. It will be useful only if it is integrated into firm long-range plans for the use of the data.

  9. SSME-HAS dynamic load simulators

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The space shuttle main engine propellant valve actuators (SSME) were designed to simulate the loads reflected into the SSME by the chamber coolant valve, the fuel preburner, and the oxidizer. The design, and functional description are included along with a list of the drawings. The load fixture control transform, friction torque, and flow calculations are reported.

  10. 30 CFR 57.9317 - Suspended loads.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Suspended loads. 57.9317 Section 57.9317 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Loading, Hauling,...

  11. 30 CFR 57.9317 - Suspended loads.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Suspended loads. 57.9317 Section 57.9317 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Loading, Hauling,...

  12. 30 CFR 57.9317 - Suspended loads.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Suspended loads. 57.9317 Section 57.9317 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Loading, Hauling,...

  13. 30 CFR 57.9317 - Suspended loads.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Suspended loads. 57.9317 Section 57.9317 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Loading, Hauling,...

  14. 30 CFR 57.9317 - Suspended loads.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Suspended loads. 57.9317 Section 57.9317 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Loading, Hauling,...

  15. 14 CFR 125.383 - Load manifest.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... airplane; (3) The maximum allowable takeoff and landing weights for that flight; (4) The center of gravity limits; (5) The center of gravity of the loaded airplane, except that the actual center of gravity need... that ensures that the center of gravity of the loaded airplane is within approved limits. In...

  16. 14 CFR 125.383 - Load manifest.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... airplane; (3) The maximum allowable takeoff and landing weights for that flight; (4) The center of gravity limits; (5) The center of gravity of the loaded airplane, except that the actual center of gravity need... that ensures that the center of gravity of the loaded airplane is within approved limits. In...

  17. 14 CFR 125.383 - Load manifest.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... airplane; (3) The maximum allowable takeoff and landing weights for that flight; (4) The center of gravity limits; (5) The center of gravity of the loaded airplane, except that the actual center of gravity need... that ensures that the center of gravity of the loaded airplane is within approved limits. In...

  18. 14 CFR 125.383 - Load manifest.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... airplane; (3) The maximum allowable takeoff and landing weights for that flight; (4) The center of gravity limits; (5) The center of gravity of the loaded airplane, except that the actual center of gravity need... that ensures that the center of gravity of the loaded airplane is within approved limits. In...

  19. 14 CFR 125.383 - Load manifest.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... airplane; (3) The maximum allowable takeoff and landing weights for that flight; (4) The center of gravity limits; (5) The center of gravity of the loaded airplane, except that the actual center of gravity need... that ensures that the center of gravity of the loaded airplane is within approved limits. In...

  20. Nutrient Load Estimates for Lake Erie 2005

    EPA Science Inventory

    Evaluation of phosphorus loads to Lake Erie is in progress for multiple uses in the Lake Erie ECOFORE Program. Emphasis is being placed on phosphorus loadings in 1976, 2005, and 2007 for model calibration and other purposes. This presentation focuses on an overview of temporal ...