A new family of Ln₇ clusters with an ideal D(3h) metal-centered trigonal prismatic geometry, and SMM and photoluminescence behaviors.

PubMed

Mazarakioti, Eleni C; Poole, Katye M; Cunha-Silva, Luis; Christou, George; Stamatatos, Theocharis C

2014-08-14

The first use of the flexible Schiff base ligand N-salicylidene-2-aminocyclohexanol in metal cluster chemistry has afforded a new family of Ln7 clusters with ideal D(3h) point group symmetry and metal-centered trigonal prismatic topology; solid-state and solution studies revealed SMM and photoluminescence behaviors.

New integrable models and analytical solutions in f (R ) cosmology with an ideal gas

NASA Astrophysics Data System (ADS)

Papagiannopoulos, G.; Basilakos, Spyros; Barrow, John D.; Paliathanasis, Andronikos

2018-01-01

In the context of f (R ) gravity with a spatially flat FLRW metric containing an ideal fluid, we use the method of invariant transformations to specify families of models which are integrable. We find three families of f (R ) theories for which new analytical solutions are given and closed-form solutions are provided.

An exact solution for ideal dam-break floods on steep slopes

USGS Publications Warehouse

Ancey, C.; Iverson, R.M.; Rentschler, M.; Denlinger, R.P.

2008-01-01

The shallow-water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce an exact analytical solution expressed in terms of readily evaluated integrals. Although the solution treats an idealized case never strictly realized in nature, it is uniquely well-suited for testing the robustness and accuracy of numerical models used to model shallow-water flows on steep slopes. Copyright 2008 by the American Geophysical Union.

Charge-Trapping-Induced Non-Ideal Behaviors in Organic Field-Effect Transistors.

PubMed

Un, Hio-Ieng; Cheng, Peng; Lei, Ting; Yang, Chi-Yuan; Wang, Jie-Yu; Pei, Jian

2018-05-01

Organic field-effect transistors (OFETs) with impressively high hole mobilities over 10 cm 2 V -1 s -1 and electron mobilities over 1 cm 2 V -1 s -1 have been reported in the past few years. However, significant non-ideal electrical characteristics, e.g., voltage-dependent mobilities, have been widely observed in both small-molecule and polymer systems. This issue makes the accurate evaluation of the electrical performance impossible and also limits the practical applications of OFETs. Here, a semiconductor-unrelated, charge-trapping-induced non-ideality in OFETs is reported, and a revised model for the non-ideal transfer characteristics is provided. The trapping process can be directly observed using scanning Kelvin probe microscopy. It is found that such trapping-induced non-ideality exists in OFETs with different types of charge carriers (p-type or n-type), different types of dielectric materials (inorganic and organic) that contain different functional groups (OH, NH 2 , COOH, etc.). As fas as it is known, this is the first report for the non-ideal transport behaviors in OFETs caused by semiconductor-independent charge trapping. This work reveals the significant role of dielectric charge trapping in the non-ideal transistor characteristics and also provides guidelines for device engineering toward ideal OFETs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The idealized self and the situated self as predictors of employee work behaviors.

PubMed

Farmer, Steven M; Van Dyne, Linn

2010-05-01

This article presents a model integrating research on idealized and situated selves. Our key premise is that identity-relevant behaviors are most likely to occur in the workplace when identities are psychologically central and activating forces make those identities salient. Analysis of matched data from 278 employees, supervisors, and organizational records generally supported our model. Helping identity and industrious work identity were positively associated with related role behaviors only when time-based occupancy in the role of organization member was high. Industrious work identity was positively associated with role behaviors only when reflected appraisals from coworkers were consistent with that identity. In contrast, reflected appraisal of helping identity had an independent relationship with identity-relevant role behaviors. Results demonstrate the importance of theory linking the idealized self and the situated self to understanding identity relations with work performances. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Analytic solution of magnetic induction distribution of ideal hollow spherical field sources

NASA Astrophysics Data System (ADS)

Xu, Xiaonong; Lu, Dingwei; Xu, Xibin; Yu, Yang; Gu, Min

2017-12-01

The Halbach type hollow spherical permanent magnet arrays (HSPMA) are volume compacted, energy efficient field sources, and capable of producing multi-Tesla field in the cavity of the array, which have attracted intense interests in many practical applications. Here, we present analytical solutions of magnetic induction to the ideal HSPMA in entire space, outside of array, within the cavity of array, and in the interior of the magnet. We obtain solutions using concept of magnetic charge to solve the Poisson's and Laplace's equations for the HSPMA. Using these analytical field expressions inside the material, a scalar demagnetization function is defined to approximately indicate the regions of magnetization reversal, partial demagnetization, and inverse magnetic saturation. The analytical field solution provides deeper insight into the nature of HSPMA and offer guidance in designing optimized one.

Evaluating Change in Behavioral Preferences: Multidimensional Scaling Single-Ideal Point Model

ERIC Educational Resources Information Center

Ding, Cody

2016-01-01

The purpose of the article is to propose a multidimensional scaling single-ideal point model as a method to evaluate changes in individuals' preferences under the explicit methodological framework of behavioral preference assessment. One example is used to illustrate the approach for a clear idea of what this approach can accomplish.

Association of sedentary behavior time with ideal cardiovascular health: the ORISCAV-LUX study.

PubMed

Crichton, Georgina E; Alkerwi, Ala'a

2014-01-01

Recently attention has been drawn to the health impacts of time spent engaging in sedentary behaviors. No studies have examined sedentary behaviors in relation to the newly defined construct of ideal cardiovascular health, which incorporates three health factors (blood pressure, total cholesterol, fasting plasma glucose) and four behaviors (physical activity, smoking, body mass index, diet). The purpose of this study was to examine associations between sedentary behaviors, including sitting time, and time spent viewing television and in front of a computer, with cardiovascular health, in a representative sample of adults from Luxembourg. A cross-sectional analysis of 1262 participants in the Observation of Cardiovascular Risk Factors in Luxembourg study was conducted, who underwent objective cardiovascular health assessments and completed the International Physical Activity Questionnaire. A Cardiovascular Health Score was calculated based on the number of health factors and behaviors at ideal levels. Sitting time on a weekday, television time, and computer time (both on a workday and a day off), were related to the Cardiovascular Health Score. Higher weekday sitting time was significantly associated with a poorer Cardiovascular Health Score (p = 0.002 for linear trend), after full adjustment for age, gender, education, income and occupation. Television time was inversely associated with the Cardiovascular Health Score, on both a workday and a day off (p = 0.002 for both). A similar inverse relationship was observed between the Cardiovascular Health Score and computer time, only on a day off (p = 0.04). Higher time spent sitting, viewing television, and using a computer during a day off may be unfavorably associated with ideal cardiovascular health.

Association of Sedentary Behavior Time with Ideal Cardiovascular Health: The ORISCAV-LUX Study

PubMed Central

Crichton, Georgina E.; Alkerwi, Ala'a

2014-01-01

Background Recently attention has been drawn to the health impacts of time spent engaging in sedentary behaviors. No studies have examined sedentary behaviors in relation to the newly defined construct of ideal cardiovascular health, which incorporates three health factors (blood pressure, total cholesterol, fasting plasma glucose) and four behaviors (physical activity, smoking, body mass index, diet). The purpose of this study was to examine associations between sedentary behaviors, including sitting time, and time spent viewing television and in front of a computer, with cardiovascular health, in a representative sample of adults from Luxembourg. Methods A cross-sectional analysis of 1262 participants in the Observation of Cardiovascular Risk Factors in Luxembourg study was conducted, who underwent objective cardiovascular health assessments and completed the International Physical Activity Questionnaire. A Cardiovascular Health Score was calculated based on the number of health factors and behaviors at ideal levels. Sitting time on a weekday, television time, and computer time (both on a workday and a day off), were related to the Cardiovascular Health Score. Results Higher weekday sitting time was significantly associated with a poorer Cardiovascular Health Score (p = 0.002 for linear trend), after full adjustment for age, gender, education, income and occupation. Television time was inversely associated with the Cardiovascular Health Score, on both a workday and a day off (p = 0.002 for both). A similar inverse relationship was observed between the Cardiovascular Health Score and computer time, only on a day off (p = 0.04). Conclusion Higher time spent sitting, viewing television, and using a computer during a day off may be unfavorably associated with ideal cardiovascular health. PMID:24925084

On the scaling analysis of the solute boundary layer in idealized growth configurations

NASA Astrophysics Data System (ADS)

Garandet, J. P.; Duffar, T.; Favier, J. J.

1990-11-01

A scaling procedure is applied to the equation governing chemical transport in idealized Czochralski and horizontal Bridgman growth experiments. Our purpose is to get a fair estimate of the solute boundary layer in front of the solidification interface. The results are very good in the Czochralski type configuration, the maximum error with respect to the semi-analytical solution of Burton, Prim and Schlichter being of the order of 20%. In the Bridgman type configuration, our predictions compare well with the values of the numerical simulations; however, more data would be needed for a definite conclusion to be drawn.

Can Customizing an Avatar Motivate Exercise Intentions and Health Behaviors Among Those with Low Health Ideals?

PubMed

Waddell, T Franklin; Sundar, S Shyam; Auriemma, Joshua

2015-11-01

Studies have shown that self-resembling avatars in health games and other applications can heighten exercise intentions, but objective self-awareness (OSA) theory suggests that this effect is likely to be true only for those who believe in the ideal of a healthy self. How can avatars be used to motivate those who do not hold this ideal and may not be motivated by avatars to pursue healthy activities? One possibility is to afford individuals the ability to customize their avatar, so they are not only more self-aware but also feel in control of their persona, both of which are necessary conditions for behavior change according to OSA. In order to test this prediction, participants in an online virtual environment created an avatar of the same sex or opposite sex by choosing among a small or large number of possible traits, then completed a series of items measuring self-awareness, sense of control, health-focused behavior, and ideal internalization. Results show that customizing a same-sex avatar can overcome differences in health intentions and behaviors between individuals with high and low levels of prior health-ideal internalization.

Approximate Solutions for Ideal Dam-Break Sediment-Laden Flows on Uniform Slopes

NASA Astrophysics Data System (ADS)

Ni, Yufang; Cao, Zhixian; Borthwick, Alistair; Liu, Qingquan

2018-04-01

Shallow water hydro-sediment-morphodynamic (SHSM) models have been applied increasingly widely in hydraulic engineering and geomorphological studies over the past few decades. Analytical and approximate solutions are usually sought to verify such models and therefore confirm their credibility. Dam-break flows are often evoked because such flows normally feature shock waves and contact discontinuities that warrant refined numerical schemes to solve. While analytical and approximate solutions to clear-water dam-break flows have been available for some time, such solutions are rare for sediment transport in dam-break flows. Here we aim to derive approximate solutions for ideal dam-break sediment-laden flows resulting from the sudden release of a finite volume of frictionless, incompressible water-sediment mixture on a uniform slope. The approximate solutions are presented for three typical sediment transport scenarios, i.e., pure advection, pure sedimentation, and concurrent entrainment and deposition. Although the cases considered in this paper are not real, the approximate solutions derived facilitate suitable benchmark tests for evaluating SHSM models, especially presently when shock waves can be numerically resolved accurately with a suite of finite volume methods, while the accuracy of the numerical solutions of contact discontinuities in sediment transport remains generally poorer.

Current versus ideal skin tones and tanning behaviors in Caucasian college women.

PubMed

Hemrich, Ashley; Pawlow, Laura; Pomerantz, Andrew; Segrist, Dan

2014-01-01

To explore tanning behaviors and whether a discrepancy between current and ideal skin tones exists. The sample included 78 Caucasian women from a mid-sized midwestern university. Data were collected in spring 2012 via a paper questionnaire. Sixty-two percent of the sample regularly engaged in salon tanning at least once per week, with an average frequency of 2.5 visits per week. Thirteen percent endorsed regularly tanning 4 or more times per week, and 26% reported visiting a tanning bed more than once in a 24-hour period. Ninety-four percent wished their current skin tone was darker, and ideal tone was significantly darker than current tone. The data suggest that the young Caucasian women in this sample tend to be dissatisfied with their current skin tone to an extent that leads the majority of them to engage in risky, potentially cancer-causing behavior by either salon tanning or considering tanning in the future as time and finances become available.

Improving Students' Understanding of the Connections between the Concepts of Real-Gas Mixtures, Gas Ideal-Solutions, and Perfect-Gas Mixtures

ERIC Educational Resources Information Center

Privat, Romain; Jaubert, Jean-Noël; Moine, Edouard

2016-01-01

In many textbooks of chemical-engineering thermodynamics, a gas mixture obeying the fundamental law pV[subscript m] = RT is most often called ideal-gas mixture (in some rare cases, the term perfect-gas mixture can be found). These textbooks also define the fundamental concept of ideal solution which in theory, can be applied indifferently to…

Analytic solution of field distribution and demagnetization function of ideal hollow cylindrical field source

NASA Astrophysics Data System (ADS)

Xu, Xiaonong; Lu, Dingwei; Xu, Xibin; Yu, Yang; Gu, Min

2017-09-01

The Halbach type hollow cylindrical permanent magnet array (HCPMA) is a volume compact and energy conserved field source, which have attracted intense interests in many practical applications. Here, using the complex variable integration method based on the Biot-Savart Law (including current distributions inside the body and on the surfaces of magnet), we derive analytical field solutions to an ideal multipole HCPMA in entire space including the interior of magnet. The analytic field expression inside the array material is used to construct an analytic demagnetization function, with which we can explain the origin of demagnetization phenomena in HCPMA by taking into account an ideal magnetic hysteresis loop with finite coercivity. These analytical field expressions and demagnetization functions provide deeper insight into the nature of such permanent magnet array systems and offer guidance in designing optimized array system.

Similarity solutions for unsteady flow behind an exponential shock in a self-gravitating non-ideal gas with azimuthal magnetic field

NASA Astrophysics Data System (ADS)

Nath, G.; Pathak, R. P.; Dutta, Mrityunjoy

2018-01-01

Similarity solutions for the flow of a non-ideal gas behind a strong exponential shock driven out by a piston (cylindrical or spherical) moving with time according to an exponential law is obtained. Solutions are obtained, in both the cases, when the flow between the shock and the piston is isothermal or adiabatic. The shock wave is driven by a piston moving with time according to an exponential law. Similarity solutions exist only when the surrounding medium is of constant density. The effects of variation of ambient magnetic field, non-idealness of the gas, adiabatic exponent and gravitational parameter are worked out in detail. It is shown that the increase in the non-idealness of the gas or the adiabatic exponent of the gas or presence of magnetic field have decaying effect on the shock wave. Consideration of the isothermal flow and the self-gravitational field increase the shock strength. Also, the consideration of isothermal flow or the presence of magnetic field removes the singularity in the density distribution, which arises in the case of adiabatic flow. The result of our study may be used to interpret measurements carried out by space craft in the solar wind and in neighborhood of the Earth's magnetosphere.

Critical behavior of the ideal-gas Bose-Einstein condensation in the Apollonian network.

PubMed

de Oliveira, I N; dos Santos, T B; de Moura, F A B F; Lyra, M L; Serva, M

2013-08-01

We show that the ideal Boson gas displays a finite-temperature Bose-Einstein condensation transition in the complex Apollonian network exhibiting scale-free, small-world, and hierarchical properties. The single-particle tight-binding Hamiltonian with properly rescaled hopping amplitudes has a fractal-like energy spectrum. The energy spectrum is analytically demonstrated to be generated by a nonlinear mapping transformation. A finite-size scaling analysis over several orders of magnitudes of network sizes is shown to provide precise estimates for the exponents characterizing the condensed fraction, correlation size, and specific heat. The critical exponents, as well as the power-law behavior of the density of states at the bottom of the band, are similar to those of the ideal Boson gas in lattices with spectral dimension d(s)=2ln(3)/ln(9/5)~/=3.74.

Equation of state of an ideal gas with nonergodic behavior in two connected vessels.

PubMed

Naplekov, D M; Semynozhenko, V P; Yanovsky, V V

2014-01-01

We consider a two-dimensional collisionless ideal gas in the two vessels connected through a small hole. One of them is a well-behaved chaotic billiard, another one is known to be nonergodic. A significant part of the second vessel's phase space is occupied by an island of stability. In the works of Zaslavsky and coauthors, distribution of Poincaré recurrence times in similar systems was considered. We study the gas pressure in the vessels; it is uniform in the first vessel and not uniform in second one. An equation of the gas state in the first vessel is obtained. Despite the very different phase-space structure, behavior of the second vessel is found to be very close to the behavior of a good ergodic billiard but of different volume. The equation of state differs from the ordinary equation of ideal gas state by an amendment to the vessel's volume. Correlation of this amendment with a share of the phase space under remaining intact islands of stability is shown.

Changing Problem Behavior Using Solution Parenting.

ERIC Educational Resources Information Center

Schatz, Mona Struhsaker; Zimmerman, Toni Schindler; Watson, Catherine

Solution parenting is designed to provide both foster parents and caseworkers a new kind of parenting for difficult children and youth in placement. The specialized training program is for those who will teach solution parenting. Objectives for trainees include: (1) identify small, positive behavioral changes; (2) recognize and use pre-existing…

The Statistical Mechanics of Ideal MHD Turbulence

NASA Technical Reports Server (NTRS)

Shebalin, John V.

2003-01-01

Turbulence is a universal, nonlinear phenomenon found in all energetic fluid and plasma motion. In particular. understanding magneto hydrodynamic (MHD) turbulence and incorporating its effects in the computation and prediction of the flow of ionized gases in space, for example, are great challenges that must be met if such computations and predictions are to be meaningful. Although a general solution to the "problem of turbulence" does not exist in closed form, numerical integrations allow us to explore the phase space of solutions for both ideal and dissipative flows. For homogeneous, incompressible turbulence, Fourier methods are appropriate, and phase space is defined by the Fourier coefficients of the physical fields. In the case of ideal MHD flows, a fairly robust statistical mechanics has been developed, in which the symmetry and ergodic properties of phase space is understood. A discussion of these properties will illuminate our principal discovery: Coherent structure and randomness co-exist in ideal MHD turbulence. For dissipative flows, as opposed to ideal flows, progress beyond the dimensional analysis of Kolmogorov has been difficult. Here, some possible future directions that draw on the ideal results will also be discussed. Our conclusion will be that while ideal turbulence is now well understood, real turbulence still presents great challenges.

Medical ethics and more: ideal theories, non-ideal theories and conscientious objection.

PubMed

Luna, Florencia

2015-01-01

Doing 'good medical ethics' requires acknowledgment that it is often practised in non-ideal circumstances! In this article I present the distinction between ideal theory (IT) and non-ideal theory (NIT). I show how IT may not be the best solution to tackle problems in non-ideal contexts. I sketch a NIT framework as a useful tool for bioethics and medical ethics and explain how NITs can contribute to policy design in non-ideal circumstances. Different NITs can coexist and be evaluated vis-à-vis the IT. Additionally, I address what an individual doctor ought to do in this non-ideal context with the view that knowledge of NITs can facilitate the decision-making process. NITs help conceptualise problems faced in the context of non-compliance and scarcity in a better and more realistic way. Deciding which policy is optimal in such contexts may influence physicians' decisions regarding their patients. Thus, this analysis-usually identified only with policy making-may also be relevant to medical ethics. Finally, I recognise that this is merely a first step in an unexplored but fundamental theoretical area and that more work needs to be done. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Demographic and Developmental Differences in the Content and Sequence of Adolescents’ Ideal Romantic Relationship Behaviors

PubMed Central

Choukas-Bradley, Sophia; Goldberg, Shoshana K.; Widman, Laura; Reese, Bianka M.; Halpern, Carolyn T.

2015-01-01

This study utilizes data from 18,392 respondents (aged 12–19) in Wave 1 of the National Longitudinal Study of Adolescent to Adult Health (Add Health) to provide a detailed descriptive analysis of U.S. adolescents’ desired behaviors in their ideal romantic relationships. Age, gender, and ethnic group differences in the desire for—and preferred sequence of—a set of activities that could occur in a hypothetical romantic relationship were explored within subsets of heterosexual (n=17,274) and sexual minority adolescents (n=1,118). Non-sexual behaviors were more commonly desired compared to sexual behaviors. The typical desired behavioral sequence was: holding hands, going out alone, telling others they were a couple, kissing, saying “I love you,” sexual touching, and finally having sex. Overall, more similarities than differences emerged across groups, with some notable differences in the percentages who desired sexual behaviors. Results provide a nuanced picture of adolescent relationship scripts, with implications for education and prevention. PMID:26431691

Possible Solutions as a Concept in Behavior Change Interventions.

PubMed

Mahoney, Diane E

2018-04-24

Nurses are uniquely positioned to implement behavior change interventions. Yet, nursing interventions have traditionally resulted from nurses problem-solving rather than allowing the patient to self-generate possible solutions for attaining specific health outcomes. The purpose of this review is to clarify the meaning of possible solutions in behavior change interventions. Walker and Avant's method on concept analysis serves as the framework for examination of the possible solutions. Possible solutions can be defined as continuous strategies initiated by patients and families to overcome existing health problems. As nurses engage in behavior change interventions, supporting patients and families in problem-solving will optimize health outcomes and transform clinical practice. © 2018 NANDA International, Inc.

Lifestyle constraints, not inadequate nutrition education, cause gap between breakfast ideals and realities among Japanese in Tokyo.

PubMed

Melby, Melissa K; Takeda, Wakako

2014-01-01

Japanese public health nutrition often promotes 'traditional' cuisine. In-depth interviews with 107 Japanese adults were conducted in Tokyo from 2009 to 2011, using free-listing methods to examine dietary ideals and realities to assess the extent to which realities reflect inadequate nutrition education or lifestyle constraints. Ideal-reality gaps were widest for breakfast. Most people reported Japanese ideals: rice and miso soup were prototypical foods. However, breakfast realities were predominantly western (bread-based). While those aged 40-59 were more likely to hold Japanese ideals (P=0.063), they were less likely to achieve them (P=0.007). All those reporting western ideals achieved them on weekdays, while only 64% of those with Japanese ideals achieved them (P<0.001). Partial correlations controlling for age and gender showed achievement of Japanese ideals were positively correlated with proportion of cooking-related housework, and negatively correlated with living standard and income. Ideal menu content was in line with current Japanese nutrition advice, suggesting that more nutrition education may not change dietary ideals or behavior. Participant-reported reasons for ideal-reality discordance demonstrate that work-life balance issues, especially lack of time and family structure/life rhythm, are the largest obstacles to the attainment of dietary ideals. People reporting 'no time' as a primary reason for ideal-reality gaps were less likely to achieve their Japanese ideals (odds ratio=0.212). Time realities of people's lives may undermine educational efforts promoting Japanese breakfasts. When dietary reality/behavior departs from guidelines, it is often assumed that people lack knowledge. If ideals are in line with dietary guidelines, then lack of knowledge is not the likely cause and nutrition education is not the optimal solution. By asking people about the reasons for gaps between their ideals and realities, we can identify barriers and design more

The influence of materialism and ideal body internalization on body-dissatisfaction and body-shaping behaviors of young men and women: support for the Consumer Culture Impact Model.

PubMed

Guðnadóttir, Unnur; Garðarsdóttir, Ragna B

2014-04-01

Exposure to media images of the 'body-perfect' ideal has been partly blamed for the pursuit of thinness among women and muscularity among men. Research has largely overlooked the materialistic messages frequently associated with these images. We present findings from two studies with Icelandic students aged 18-21, one focusing on young women (n = 303) and one on young men (n = 226), which test associations of materialistic and body-perfect ideals with body dissatisfaction and excessive body shaping behaviors. In both studies, the internalization of materialistic values is strongly linked to the internalization of body-perfect ideals: the thin-ideal for young women, and the muscular-ideal for young men. A materialist value orientation also predicted body dissatisfaction in both studies, and was linked to body shaping behaviors, albeit differently for young women and men. Thus, the research identifies materialism as a further correlate of both body dissatisfaction and excessive body-shaping behaviors. The findings support Dittmar's (2008) Consumer Culture Impact Model, which proposes that the body-perfect and 'material good life' ideals jointly impact well-being. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Adding thin-ideal internalization and impulsiveness to the cognitive-behavioral model of bulimic symptoms.

PubMed

Schnitzler, Caroline E; von Ranson, Kristin M; Wallace, Laurel M

2012-08-01

This study evaluated the cognitive-behavioral (CB) model of bulimia nervosa and an extension that included two additional maintaining factors - thin-ideal internalization and impulsiveness - in 327 undergraduate women. Participants completed measures of demographics, self-esteem, concern about shape and weight, dieting, bulimic symptoms, thin-ideal internalization, and impulsiveness. Both the original CB model and the extended model provided good fits to the data. Although structural equation modeling analyses suggested that the original CB model was most parsimonious, hierarchical regression analyses indicated that the additional variables accounted for significantly more variance. Additional analyses showed that the model fit could be improved by adding a path from concern about shape and weight, and deleting the path from dieting, to bulimic symptoms. Expanding upon the factors considered in the model may better capture the scope of variables maintaining bulimic symptoms in young women with a range of severity of bulimic symptoms. Copyright © 2012 Elsevier Ltd. All rights reserved.

Threat of the thin-ideal body image and body malleability beliefs: effects on body image self-discrepancies and behavioral intentions.

PubMed

Arciszewski, Thomas; Berjot, Sophie; Finez, Lucie

2012-06-01

This study examined the effect of the threat aroused by the perception of thin-ideal images combined with beliefs about the malleability of the body on perceived/objective, ideal/objective and ought/objective body image self-discrepancies. An experimental computer program enabled women (N=82) to artificially increase or decrease the shape of their own body (previously photographed) in response to questions about their "actual", "ideal" and "ought" body self-perceptions. As predicted, results showed that women had greater body self-discrepancies when confronted with threatening thin ideals, regardless of their body mass index. The size of this trend depended on the way they were made to think of their body (malleable vs. fixed). Findings also suggested a possible relationship between body self-representations and eating behaviors or intentions. The impact of thin-ideal threats and body malleability beliefs on body perception is discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Non-Ideality in Solvent Extraction Systems: PNNL FY 2014 Status Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levitskaia, Tatiana G.; Chatterjee, Sayandev; Pence, Natasha K.

The overall objective of this project is to develop predictive modeling capabilities for advanced fuel cycle separation processes by gaining a fundamental quantitative understanding of non-ideality effects and speciation in relevant aqueous and organic solutions. Aqueous solutions containing actinides and lanthanides encountered during nuclear fuel reprocessing have high ionic strength and do not behave as ideal solutions. Activity coefficients must be calculated to take into account the deviation from ideality and predict their behavior. In FY 2012-2013, a convenient method for determining activity effects in aqueous electrolyte solutions was developed. Our initial experiments demonstrated that water activity and osmotic coefficientsmore » of the electrolyte solutions can be accurately measured by the combination of two techniques, a Water Activity Meter and Vapor Pressure Osmometry (VPO). The water activity measurements have been conducted for binary lanthanide solutions in wide concentration range for all lanthanides (La-Lu with the exception of Pm). The osmotic coefficients and Pitzer parameters for each binary system were obtained by the least squares fitting of the water activity data. However, application of Pitzer model for the quantitative evaluation of the activity effects in the multicomponent mixtures is difficult due to the large number of the required interaction parameters. In FY 2014, the applicability of the Bromley model for the determination of the Ln(NO 3) 3 activity coefficients was evaluated. The new Bromley parameters for the binary Ln(NO 3) 3 electrolytes were obtained based on the available literature and our experimental data. This allowed for the accurate prediction of the Ln(NO 3) 3 activity coefficients for the binary Ln(NO 3) 3 electrolytes. This model was then successfully implemented for the determination of the Ln(NO 3) 3 activity coefficients in the ternary Nd(NO 3) 3/HNO 3/H2O, Eu(NO 3) 3/HNO 3/H 2O, and Eu(NO 3) 3/NaNO 3/H 2O

Family Life and Developmental Idealism in Yazd, Iran

PubMed Central

Abbasi-Shavazi, Mohammad Jalal; Askari-Nodoushan, Abbas

2012-01-01

BACKGROUND This paper is motivated by the theory that developmental idealism has been disseminated globally and has become an international force for family and demographic change. Developmental idealism is a set of cultural beliefs and values about development and how development relates to family and demographic behavior. It holds that modern societies are causal forces producing modern families, that modern families help to produce modern societies, and that modern family change is to be expected. OBJECTIVE We examine the extent to which developmental idealism has been disseminated in Iran. We also investigate predictors of the dissemination of developmental idealism. METHODS We use survey data collected in 2007 from a sample of women in Yazd, a city in Iran. We examine the distribution of developmental idealism in the sample and the multivariate predictors of developmental idealism. RESULTS We find considerable support for the expectation that many elements of developmental idealism have been widely disseminated. Statistically significant majorities associate development with particular family attributes, believe that development causes change in families, believe that fertility reductions and age-at-marriage increases help foster development, and perceive family trends in Iran headed toward modernity. As predicted, parental education, respondent education, and income affect adherence to developmental idealism. CONCLUSIONS Developmental idealism has been widely disseminated in Yazd, Iran and is related to social and demographic factors in predicted ways. COMMENTS Although our data come from only one city, we expect that developmental idealism has been widely distributed in Iran, with important implications for family and demographic behavior. PMID:22942772

Electrochemical Behavior of Biomedical Titanium Alloys Coated with Diamond Carbon in Hanks' Solution

NASA Astrophysics Data System (ADS)

Gnanavel, S.; Ponnusamy, S.; Mohan, L.; Radhika, R.; Muthamizhchelvan, C.; Ramasubramanian, K.

2018-03-01

Biomedical implants in the knee and hip are frequent failures because of corrosion and stress on the joints. To solve this important problem, metal implants can be coated with diamond carbon, and this coating plays a critical role in providing an increased resistance to implants toward corrosion. In this study, we have employed diamond carbon coating over Ti-6Al-4V and Ti-13Nb-13Zr alloys using hot filament chemical vapor deposition method which is well-established coating process that significantly improves the resistance toward corrosion, wears and hardness. The diamond carbon-coated Ti-13Nb-13Zr alloy showed an increased microhardness in the range of 850 HV. Electrochemical impedance spectroscopy and polarization studies in SBF solution (simulated body fluid solution) were carried out to understand the in vitro behavior of uncoated as well as coated titanium alloys. The experimental results showed that the corrosion resistance of Ti-13Nb-13Zr alloy is relatively higher when compared with diamond carbon-coated Ti-6Al-4V alloys due to the presence of β phase in the Ti-13Nb-13Zr alloy. Electrochemical impedance results showed that the diamond carbon-coated alloys behave as an ideal capacitor in the body fluid solution. Moreover, the stability in mechanical properties during the corrosion process was maintained for diamond carbon-coated titanium alloys.

Melting behavior of (Mg,Fe)O solid solutions at high pressure

NASA Astrophysics Data System (ADS)

Zhang, Li; Fei, Yingwei

2008-07-01

High pressure melting of (Mg,Fe)O ferropericlase, the second most abundant mineral in the Earth's lower mantle, is of fundamental importance for understanding the chemical differentiation, geodynamics and thermal evolution of the Earth's interior. We report the first systematic experimental study of melting behavior in the MgO-FeO system up to 3600 K and 7 GPa, indicating the ideal solution between solid and liquid (Mg,Fe)O in the MgO-rich portion. The zero pressure melting slope of MgO is ~221 K/GPa derived from our resistance heating measurements, which is several times higher than the value from the previous measurements in a CO2-laser heated diamond anvil cell, but consistent with the theoretically predicted melting curves. Our results combined with the previous first-principles simulations suggest that the melting temperature of MgO-rich (Mg,Fe)O is significantly higher than the geotherm through the lower mantle and this would place an upper bound on the solidus of the lower mantle.

Universal ideal behavior and macroscopic work relation of linear irreversible stochastic thermodynamics

NASA Astrophysics Data System (ADS)

Ma, Yi-An; Qian, Hong

2015-06-01

We revisit the Ornstein-Uhlenbeck (OU) process as the fundamental mathematical description of linear irreversible phenomena, with fluctuations, near an equilibrium. By identifying the underlying circulating dynamics in a stationary process as the natural generalization of classical conservative mechanics, a bridge between a family of OU processes with equilibrium fluctuations and thermodynamics is established through the celebrated Helmholtz theorem. The Helmholtz theorem provides an emergent macroscopic ‘equation of state’ of the entire system, which exhibits a universal ideal thermodynamic behavior. Fluctuating macroscopic quantities are studied from the stochastic thermodynamic point of view and a non-equilibrium work relation is obtained in the macroscopic picture, which may facilitate experimental study and application of the equalities due to Jarzynski, Crooks, and Hatano and Sasa.

Ideal affect in daily life: implications for affective experience, health, and social behavior.

PubMed

Tsai, Jeanne L

2017-10-01

Over the last decade, researchers have increasingly demonstrated that ideal affect-the affective states that people value and ideally want to feel-shapes different aspects of daily life. Here I briefly review Affect Valuation Theory (AVT), which integrates ideal affect into existing models of affect and emotion by identifying the causes and consequences of variation in ideal affect. I then describe recent research that applies AVT to the valuation of negative states as well as more complex states, examines how ideal affect shapes momentary affective experience, suggests that ideal affect has both direct and indirect effects on health, and illustrates that people's ideal affect shapes how they judge and respond to others. Finally, I discuss the implications of cultural and individual differences in ideal affect for clinical, educational, work, and leisure settings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ideals as Anchors for Relationship Experiences

PubMed Central

Frye, Margaret; Trinitapoli, Jenny

2016-01-01

Research on young-adult sexuality in sub-Saharan Africa typically conceptualizes sex as an individual-level risk behavior. We introduce a new approach that connects the conditions surrounding the initiation of sex with subsequent relationship well-being, examines relationships as sequences of interdependent events, and indexes relationship experiences to individually held ideals. New card-sort data from southern Malawi capture young women’s relationship experiences and their ideals in a sequential framework. Using optimal matching, we measure the distance between ideal and experienced relationship sequences to (1) assess the associations between ideological congruence and perceived relationship well-being, (2) compare this ideal-based approach to other experience-based alternatives, and (3) identify individual- and couple-level correlates of congruence between ideals and experiences in the romantic realm. We show that congruence between ideals and experiences conveys relationship well-being along four dimensions: expressions of love and support, robust communication habits, perceived biological safety, and perceived relationship stability. We further show that congruence is patterned by socioeconomic status and supported by shared ideals within romantic dyads. We argue that conceiving of ideals as anchors for how sexual experiences are manifest advances current understandings of romantic relationships, and we suggest that this approach has applications for other domains of life. PMID:27110031

Exact Solution of the Two-Dimensional Problem on an Impact Ideal-Liquid Jet

NASA Astrophysics Data System (ADS)

Belik, V. D.

2018-05-01

The two-dimensional problem on the collision of a potential ideal-liquid jet, outflowing from a reservoir through a nozzle, with an infinite plane obstacle was considered for the case where the distance between the nozzle exit section and the obstacle is finite. An exact solution of this problem has been found using methods of the complex-variable function theory. Simple analytical expressions for the complex velocity of the liquid, its flow rate, and the force of action of the jet on the obstacle have been obtained. The velocity distributions of the liquid at the nozzle exit section, in the region of spreading of the jet, and at the obstacle have been constructed for different distances between the nozzle exit section and the obstacle. Analytical expressions for the thickness of the boundary layer and the Nusselt number at the point of stagnation of the jet have been obtained. A number of distributions of the local friction coefficient and the Nusselt number of the indicated jet are presented.

Investigation of the relationships between the thermodynamic phase behavior and gelation behavior of a series of tripodal trisamide compounds

NASA Astrophysics Data System (ADS)

Feng, Li

Low molecular weight organic gelators(LMOGs) are important due to potential applications in many fields. Currently, most of the major studies focus on the empirical explanation of the crystallization for gelator assembly formation and morphologies, few efforts have been devoted to the thermodynamic phase behaviors and the effect of the non-ideal solution behavior on the structure of the resultant gels. In this research, tripodal trisamide compounds, synthesized from tris(2-aminoethyl)amine (TREN) by condensation with different acid chlorides, were studied as model LMOGs due to the simple one-step reaction and the commercially available chemical reactants. Gelation of organic solvents was investigated as a function of concentration and solvent solubility parameter.It has been found that the introduction of branches or cyclic units have dramatically improves the gelation ability compared to linear alkyl peripheral units. Fitting the liquidus lines using the regular solution model and calculation of the trisamide solubility parameter using solubility parameter theory gave good agreement with the trisamide solubility parameter calculated by group contribution methods. These results demonstrate that non-ideal solution behavior is an important factor in the gelation behavior of low molecular mass organic gelators. Understanding and controlling the thermodynamics and phase behaviors of the gel systems will provide effective ways to produce new efficient LMOGs in the future.

A Numerical Study of the Non-Ideal Behavior, Parameters, and Novel Applications of an Electrothermal Plasma Source

NASA Astrophysics Data System (ADS)

Winfrey, A. Leigh

Electrothermal plasma sources have numerous applications including hypervelocity launchers, fusion reactor pellet injection, and space propulsion systems. The time evolution of important plasma parameters at the source exit is important in determining the suitability of the source for different applications. In this study a capillary discharge code has been modified to incorporate non-ideal behavior by using an exact analytical model for the Coulomb logarithm in the plasma electrical conductivity formula. Actual discharge currents from electrothermal plasma experiments were used and code results for both ideal and non-ideal plasma models were compared to experimental data, specifically the ablated mass from the capillary and the electrical conductivity as measured by the discharge current and the voltage. Electrothermal plasma sources operating in the ablation-controlled arc regime use discharge currents with pulse lengths between 100 micros to 1 ms. Faster or longer or extended flat-top pulses can also be generated to satisfy various applications of ET sources. Extension of the peak current for up to an additional 1000 micros was tested. Calculations for non-ideal and ideal plasma models show that extended flattop pulses produce more ablated mass, which scales linearly with increased pulse length while other parameters remain almost constant. A new configuration of the PIPE source has been proposed in order to investigate the formation of plasmas from mixed materials. The electrothermal segmented plasma source can be used for studies related to surface coatings, surface modification, ion implantation, materials synthesis, and the physics of complex mixed plasmas. This source is a capillary discharge where the ablation liner is made from segments of different materials instead of a single sleeve. This system should allow for the modeling and characterization of the growth plasma as it provides all materials needed for fabrication through the same method. An

The effects of "thin ideal" media on women's body image concerns and eating-related intentions: the beneficial role of an autonomous regulation of eating behaviors.

PubMed

Mask, Lisa; Blanchard, Céline M

2011-09-01

The present study examines the protective role of an autonomous regulation of eating behaviors (AREB) on the relationship between trait body dissatisfaction and women's body image concerns and eating-related intentions in response to "thin ideal" media. Undergraduate women (n=138) were randomly assigned to view a "thin ideal" video or a neutral video. As hypothesized, trait body dissatisfaction predicted more negative affect and size dissatisfaction following exposure to the "thin ideal" video among women who displayed less AREB. Conversely, trait body dissatisfaction predicted greater intentions to monitor food intake and limit unhealthy foods following exposure to the "thin ideal" video among women who displayed more AREB. Copyright © 2011 Elsevier Ltd. All rights reserved.

Group choice: the ideal free distribution of human social behavior.

PubMed

Kraft, J R; Baum, W M

2001-07-01

Group choice refers to the distribution of group members between two choice alternatives over time. The ideal free distribution (IFD), an optimal foraging model from behavioral ecology, predicts that the ratio of foragers at two resource sites should equal the ratio of obtained resources, a prediction that is formally analogous to the matching law of individual choice, except that group choice is a social phenomenon. Two experiments investigated the usefulness of IFD analyses of human group choice and individual-based explanations that might account for the group-level events. Instead of nonhuman animals foraging at two sites for resources, a group of humans chose blue and red cards to receive points that could earn cash prizes. The groups chose blue and red cards in ratios in positive relation to the ratios of points associated with the cards. When group choice ratios and point ratios were plotted on logarithmic coordinates and fitted with regression lines, the slopes (i.e., sensitivity measures) approached 1.0 but tended to fall short of it (i.e., undermatching), with little bias and little unaccounted for variance. These experiments demonstrate that an IFD analysis of group choice is possible and useful, and suggest that group choice may be explained by the individual members' tendency to optimize reinforcement.

Nature and consequences of protein-protein interactions in high protein concentration solutions.

PubMed

Saluja, Atul; Kalonia, Devendra S

2008-06-24

High protein concentration solutions are becoming increasingly important in the pharmaceutical industry. The solution behavior of proteins at high concentrations can markedly differ from that predicted based on dilute solution analysis due to thermodynamic non-ideality in these solutions. The non-ideality observed in these systems is related to the protein-protein interactions (PPI). Different types of forces play a key role in determining the overall nature and extent of these PPI and their relative contributions are affected by solute and solvent properties. However, individual contributions of these forces to the solution properties of concentrated protein solutions are not fully understood. The role of PPI, driven by these intermolecular forces, in governing solution rheology and physical stability of high protein concentration solutions is discussed from the point of view of pharmaceutical product development. Investigation of protein self-association and aggregation in concentrated protein solutions is crucial for ensuring the safety and efficacy of the final product for the duration of the desired product shelf life. Understanding rheology of high concentration protein solutions is critical for addressing issues during product manufacture and administration of final formulation to the patient. To this end, analysis of solution viscoelastic character can also provide an insight into the nature of PPI affecting solution rheology.

Invariant and partially-invariant solutions of the equations describing a non-stationary and isentropic flow for an ideal and compressible fluid in (3 + 1) dimensions

NASA Astrophysics Data System (ADS)

Grundland, A. M.; Lalague, L.

1996-04-01

This paper presents a new method of constructing, certain classes of solutions of a system of partial differential equations (PDEs) describing the non-stationary and isentropic flow for an ideal compressible fluid. A generalization of the symmetry reduction method to the case of partially-invariant solutions (PISs) has been formulated. We present a new algorithm for constructing PISs and discuss in detail the necessary conditions for the existence of non-reducible PISs. All these solutions have the defect structure 0305-4470/29/8/019/img1 and are computed from four-dimensional symmetric subalgebras. These theoretical considerations are illustrated by several examples. Finally, some new classes of invariant solutions obtained by the symmetry reduction method are included. These solutions represent central, conical, rational, spherical, cylindrical and non-scattering double waves.

The impact of exposure to images of ideally thin models in TV commercials on eating behavior: an experimental study with women diagnosed with bulimia nervosa.

PubMed

Rühl, Ilka; Legenbauer, Tanja; Hiller, Wolfgang

2011-09-01

This study investigates whether eating behavior in women with diagnosed bulimia nervosa is influenced by prior exposure to images of ideally thin models. Twenty-six participants diagnosed with bulimia nervosa (BN) and 30 normal controls (NC) were exposed to body-related and neutral TV commercials; then food that typically triggers binge eating was provided, and the amount of food eaten was measured. No significant difference for food intake between NC and BN could be found, but food intake for BN was predicted by the degree of thoughts related to eating behaviors during exposure to the thin ideal. No impact of general body image or eating pathology on food intake could be found. The results emphasize the importance of action-relevance of dysfunctional cognitions for the maintenance of eating-disordered behaviors in women with bulimia nervosa, when exposed to eating-disorder-specific triggers. Copyright © 2011 Elsevier Ltd. All rights reserved.

Self-Similar Apical Sharpening of an Ideal Perfecting Conducting Fluid Subject to Maxwell Stresses

NASA Astrophysics Data System (ADS)

Zhou, Chengzhe; Troian, Sandra M.

2016-11-01

We examine the apical behavior of an ideal, perfectly conducting incompressible fluid surrounded by vacuum in circumstances where the capillary, Maxwell and inertial forces contribute to formation of a liquid cone. A previous model based on potential flow describes a family of self-similar solutions with conic cusps whose interior angles approach the Taylor cone angle. These solutions were obtained by matching powers of the leading order terms in the velocity and electric field potential to the asymptotic form dictated by a stationary cone shape. In re-examining this earlier work, we have found a more important, neglected leading order term in the velocity and field potentials, which satisfies the governing, interfacial and far-field conditions as well. This term allows for the development of additional self-similar, sharpening apical shapes, including time reversed solutions for conic tip recoil after fluid ejection. We outline the boundary-element technique for solving the exact similarity solutions, which have parametric dependence on the far-field conditions, and discuss consequences of our findings.

Exact Solutions to Several Nonlinear Cases of Generalized Grad-Shafranov Equation for Ideal Magnetohydrodynamic Flows in Axisymmetric Domain

NASA Astrophysics Data System (ADS)

Adem, Abdullahi Rashid; Moawad, Salah M.

2018-05-01

In this paper, the steady-state equations of ideal magnetohydrodynamic incompressible flows in axisymmetric domains are investigated. These flows are governed by a second-order elliptic partial differential equation as a type of generalized Grad-Shafranov equation. The problem of finding exact equilibria to the full governing equations in the presence of incompressible mass flows is considered. Two different types of constraints on position variables are presented to construct exact solution classes for several nonlinear cases of the governing equations. Some of the obtained results are checked for their applications to magnetic confinement plasma. Besides, they cover many previous configurations and include new considerations about the nonlinearity of magnetic flux stream variables.

Solution-phase electronegativity scale: insight into the chemical behaviors of metal ions in solution.

PubMed

Li, Keyan; Li, Min; Xue, Dongfeng

2012-04-26

By incorporating the solvent effect into the Born effective radius, we have proposed an electronegativity scale of metal ions in aqueous solution with the most common oxidation states and hydration coordination numbers in terms of the effective ionic electrostatic potential. It is found that the metal ions in aqueous solution are poorer electron acceptors compared to those in the gas phase. This solution-phase electronegativity scale shows its efficiency in predicting some important properties of metal ions in aqueous solution such as the aqueous acidities of the metal ions, the stability constants of metal complexes, and the solubility product constants of the metal hydroxides. We have elaborated that the standard reduction potential and the solution-phase electronegativity are two different quantities for describing the processes of metal ions in aqueous solution to soak up electrons with different final states. This work provides a new insight into the chemical behaviors of the metal ions in aqueous solution, indicating a potential application of this electronegativity scale to the design of solution reactions.

Impact of non-ideal analyte behavior on the separation of protein aggregates by asymmetric flow field-flow fractionation.

PubMed

Boll, Björn; Josse, Lena; Heubach, Anja; Hochenauer, Sophie; Finkler, Christof; Huwyler, Jörg; Koulov, Atanas V

2018-04-25

Asymmetric flow field-flow fractionation is a valuable tool for the characterization of protein aggregates in biotechnology owing to its broad size range and unique separation principle. However, in practice asymmetric flow field-flow fractionation is non-trivial to use due to the major deviations from theory and the influence on separation by various factors that are not fully understood. Here we report methods to assess the non-ideal effects that influence asymmetric flow field-flow fractionation separation and for the first time identify experimentally the main factors that impact it. Furthermore, we propose new approaches to minimize such non-ideal behavior, showing that by adjusting the mobile phase composition (pH and ionic strength) the resolution of asymmetric flow field-flow fractionation separation can be drastically improved. Additionally, we propose a best practice method for new proteins. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

An ideal sealed source life-cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tompkins, Joseph Andrew

2009-01-01

system they we have today. This regulation created a new regulatory framework seen as promising at the time. However, now they recognize that, despite the good intentions, the NIJWP/85 has not solved any source disposition problems. The answer to these sealed source disposition problems is to adopt a philosophy to correct these regulatory issues, determine an interim solution, execute that solution until there is a minimal backlog of sources to deal with, and then let the mechanisms they have created solve this problem into the foreseeable future. The primary philosophical tenet of the ideal sealed source life cycle follows. You do not allow the creation (or importation) of any source whose use cannot be justified, which cannot be affordably shipped, or that does not have a well-delinated and affordable disposition pathway. The path forward dictates that we fix the problem by embracing the Ideal Source Life cycle. In figure 1, we can see some of the elements of the ideal source life cycle. The life cycle is broken down into four portions, manufacture, use, consolidation, and disposition. These four arbitrary elements allow them to focus on the ideal life cycle phases that every source should go through between manufacture and final disposition. As we examine the various phases of the sealed source life cycle, they pick specific examples and explore the adoption of the ideal life cycle model.« less

Handgrip Strength and Ideal Cardiovascular Health among Colombian Children and Adolescents.

PubMed

Ramírez-Vélez, Robinson; Tordecilla-Sanders, Alejandra; Correa-Bautista, Jorge Enrique; Peterson, Mark D; Garcia-Hermoso, Antonio

2016-12-01

To evaluate the association between handgrip strength and ideal cardiovascular health (CVH) in Colombian children and adolescents. During the 2014-2015 school years, we examined a cross-sectional component of the FUPRECOL (Association for Muscular Strength with Early Manifestation of Cardiovascular Disease Risk Factors among Colombian Children and Adolescents) study. Participants included 1199 (n = 627 boys) youths from Bogota (Colombia). Handgrip strength was measured with a standard adjustable hand held dynamometer and expressed relative to body mass (handgrip/body mass) and as absolute values in kilograms. Ideal CVH, as defined by the American Heart Association, was determined as meeting ideal levels of the following components: 4 behaviors (smoking status, body mass index, cardiorespiratory fitness, and diet) and 3 factors (total cholesterol, blood pressure, and glucose). Higher levels of handgrip strength (both absolute and relative values) were associated with a higher frequency of ideal CVH metrics in both sexes (P for trend ≤ .001). Also, higher levels of handgrip strength were associated with a greater number of ideal health behaviors (P for trend < .001 in both boys and girls), and with a higher number of ideal health factors in boys (P for trend < .001). Finally, levels of handgrip strength were similar between ideal versus nonideal glucose or total cholesterol groups in girls. Handgrip strength was strongly associated with ideal CVH in Colombian children and adolescents, and thus supports the relevance of early targeted interventions to promote strength adaptation and preservation as part of primordial prevention. Copyright © 2016 Elsevier Inc. All rights reserved.

Ideal Cardiovascular Health and Incident Cardiovascular Events

PubMed Central

Ommerborn, Mark J.; Blackshear, Chad T.; Hickson, DeMarc A.; Griswold, Michael E.; Kwatra, Japneet; Djousse, Luc; Clark, Cheryl R.

2016-01-01

Introduction The epidemiology of American Heart Association ideal cardiovascular health (CVH) metrics has not been fully examined in African Americans. This study examines associations of CVH metrics with incident cardiovascular disease (CVD) in the Jackson Heart Study, a longitudinal cohort study of CVD in African Americans. Methods Jackson Heart Study participants without CVD (N=4,702) were followed prospectively between 2000 and 2011. Incidence rates and Cox proportional hazard ratios estimated risks for incident CVD (myocardial infarction, stroke, cardiac procedures, and CVD mortality) associated with seven CVH metrics by sex. Analyses were performed in 2015. Results Participants were followed for a median 8.3 years; none had ideal health on all seven CVH metrics. The prevalence of ideal health was low for nutrition, physical activity, BMI, and blood pressure metrics. The age-adjusted CVD incidence rate (IR) per 1,000 person years was highest for individuals with the least ideal health metrics: zero to one (IR=12.5, 95% CI=9.7, 16.1), two (IR=8.2, 95% CI=6.5, 10.4), three (IR=5.7, 95% CI=4.2, 7.6), and four or more (IR=3.4, 95% CI=2.0, 5.9). Adjusting for covariates, individuals with four or more ideal CVH metrics had lower risks of incident CVD compared with those with zero or one ideal CVH metric (hazard ratio, 0.29; 95% CI=0.17, 0.52; p<0.001). Conclusions African Americans with more ideal CVH metrics have lower risks of incident CVD. Comprehensive preventive behavioral and clinical supports should be intensified to improve CVD risk for African Americans with few ideal CVH metrics. PMID:27539974

Energy behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stern, P.C.; Kirkpatrick, E.M.

1977-12-01

The energy crisis is approached as a social and psychological problem with solutions based on an understanding of principles of attitude and behavior change. Propaganda calling for voluntary energy conservation has had little effect, and incentive systems present several serious drawbacks. The author believes that the ideal role of both incentives and persuasion is to influence the behavior of groups who in turn would maintain individual behavior and attitudes by social pressure. Thus a program of incentives and education directed at groups of people may effectively increase conservation and change related attitudes without increasing reactance. The author presents 2 strategiesmore » to cope with the energy problem: one relies strongly on government action, combining appeal to national feelings and a threat to future coercion to change attitudes and behavior; the other uses incentives to communities for conservation and development of renewable energy resources.« less

Glass transition behavior of ternary disaccharide-ethylene glycol-water solutions

NASA Astrophysics Data System (ADS)

Yu, Tongxu; Zhao, Lishan; Wang, Qiang; Cao, Zexian

2017-06-01

Glass transition behavior of ternary disaccharide-ethylene glycol-water solutions, in reference to that of the binary combinations, has been investigated towards a better understanding of their cryoprotective ability. In water-deficient solutions, the disaccharides, including trehalose, sucrose and maltose, can associate with more than 100 ethylene glycol molecules to form amorphous complex, one order of magnitude larger than the corresponding hydration numbers. In water-rich solutions, a second glass transition emerges with increasing molar fraction of ethylene glycol, indicating the possible synergy of disaccharides and ethylene glycol in vitrification of the ternary aqueous solution.

Not All Ideals are Equal: Intrinsic and Extrinsic Ideals in Relationships.

PubMed

Rodriguez, Lindsey M; Hadden, Benjamin W; Knee, C Raymond

2015-03-01

The ideal standards model suggests that greater consistency between ideal standards and actual perceptions of one's relationship predicts positive relationship evaluations; however, no research has evaluated whether this differs across types of ideals. A self-determination theory perspective was derived to test whether satisfaction of intrinsic ideals buffers the importance of extrinsic ideals. Participants (N=195) in committed relationships directly and indirectly reported the extent to which their partner met their ideal on two dimensions: intrinsic (e.g., warm, intimate) and extrinsic (e.g., attractive, successful). Relationship need fulfillment and relationship quality were also assessed. Hypotheses were largely supported, such that satisfaction of intrinsic ideals more strongly predicted relationship functioning, and satisfaction of intrinsic ideals buffered the relevance of extrinsic ideals for outcomes.

Not All Ideals are Equal: Intrinsic and Extrinsic Ideals in Relationships

PubMed Central

Rodriguez, Lindsey M.; Hadden, Benjamin W.; Knee, C. Raymond

2015-01-01

The ideal standards model suggests that greater consistency between ideal standards and actual perceptions of one’s relationship predicts positive relationship evaluations; however, no research has evaluated whether this differs across types of ideals. A self-determination theory perspective was derived to test whether satisfaction of intrinsic ideals buffers the importance of extrinsic ideals. Participants (N=195) in committed relationships directly and indirectly reported the extent to which their partner met their ideal on two dimensions: intrinsic (e.g., warm, intimate) and extrinsic (e.g., attractive, successful). Relationship need fulfillment and relationship quality were also assessed. Hypotheses were largely supported, such that satisfaction of intrinsic ideals more strongly predicted relationship functioning, and satisfaction of intrinsic ideals buffered the relevance of extrinsic ideals for outcomes. PMID:25821396

Ideal Directed-Energy System To Defeat Small Unmanned Aircraft System Swarms

DTIC Science & Technology

2017-05-21

AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY IDEAL DIRECTED- ENERGY SYSTEM TO DEFEAT SMALL UNMANNED AIRCRAFT SYSTEM SWARMS by David F. Pina...directed energy (DE) developmental systems indicate this class of weapons is the best solution. A review of several continuous wave laser, pulsed high...powered microwave, and electronic warfare/jamming systems indicate the following attributes as ideal for a future directed energy weapon (DEW) system

Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions.

PubMed

Uralcan, Betul; Aksay, Ilhan A; Debenedetti, Pablo G; Limmer, David T

2016-07-07

We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid in agreement with recent experimental observations. The nonmonotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. Mirroring the capacitance, we find that the characteristic decay length of charge density correlations away from the electrode is also nonmonotonic. The correlation length first decreases with ion concentration as a result of better electrostatic screening but increases with ion concentration as a result of enhanced steric interactions. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such capacitive behavior is expected to be generic.

Detecting the Biopolymer Behavior of Graphene Nanoribbons in Aqueous Solution

NASA Astrophysics Data System (ADS)

Wijeratne, Sithara S.; Penev, Evgeni S.; Lu, Wei; Li, Jingqiang; Duque, Amanda L.; Yakobson, Boris I.; Tour, James M.; Kiang, Ching-Hwa

2016-08-01

Graphene nanoribbons (GNR), can be prepared in bulk quantities for large-area applications by reducing the product from the lengthwise oxidative unzipping of multiwalled carbon nanotubes (MWNT). Recently, the biomaterials application of GNR has been explored, for example, in the pore to be used for DNA sequencing. Therefore, understanding the polymer behavior of GNR in solution is essential in predicting GNR interaction with biomaterials. Here, we report experimental studies of the solution-based mechanical properties of GNR and their parent products, graphene oxide nanoribbons (GONR). We used atomic force microscopy (AFM) to study their mechanical properties in solution and showed that GNR and GONR have similar force-extension behavior as in biopolymers such as proteins and DNA. The rigidity increases with reducing chemical functionalities. The similarities in rigidity and tunability between nanoribbons and biomolecules might enable the design and fabrication of GNR-biomimetic interfaces.

Detecting the Biopolymer Behavior of Graphene Nanoribbons in Aqueous Solution

PubMed Central

Wijeratne, Sithara S.; Penev, Evgeni S.; Lu, Wei; Li, Jingqiang; Duque, Amanda L.; Yakobson, Boris I.; Tour, James M.; Kiang, Ching-Hwa

2016-01-01

Graphene nanoribbons (GNR), can be prepared in bulk quantities for large-area applications by reducing the product from the lengthwise oxidative unzipping of multiwalled carbon nanotubes (MWNT). Recently, the biomaterials application of GNR has been explored, for example, in the pore to be used for DNA sequencing. Therefore, understanding the polymer behavior of GNR in solution is essential in predicting GNR interaction with biomaterials. Here, we report experimental studies of the solution-based mechanical properties of GNR and their parent products, graphene oxide nanoribbons (GONR). We used atomic force microscopy (AFM) to study their mechanical properties in solution and showed that GNR and GONR have similar force-extension behavior as in biopolymers such as proteins and DNA. The rigidity increases with reducing chemical functionalities. The similarities in rigidity and tunability between nanoribbons and biomolecules might enable the design and fabrication of GNR-biomimetic interfaces. PMID:27503635

Personality traits and appearance-ideal internalization: Differential associations with body dissatisfaction and compulsive exercise.

PubMed

Martin, Shelby J; Racine, Sarah E

2017-12-01

Thin-ideal internalization is a robust risk factor for body dissatisfaction and eating pathology. Conversely, athletic-ideal internalization is often unrelated to body dissatisfaction, but predicts compulsive exercise (i.e., rigid, rule-driven exercise that is continued despite adverse consequences). Distinct personality traits could relate to internalization of different appearance ideals, which may be associated with divergent eating disorder outcomes. Past research has shown that neuroticism is related to body dissatisfaction, whereas extraversion and conscientiousness have been associated with regular and problematic exercise. The current study examined associations among personality traits (i.e., neuroticism, extraversion, conscientiousness), appearance-ideal internalization (i.e., thin- and athletic-ideal), and eating disorder cognitions/behaviors (i.e., body dissatisfaction, compulsive exercise) among 531 college men and women. Moreover, we tested whether appearance-ideal internalization mediated the relationships between personality traits with body dissatisfaction and compulsive exercise. As expected, body dissatisfaction was positively related to neuroticism, and compulsive exercise was positively associated with extraversion. Thin-ideal internalization positively correlated with neuroticism, athletic-ideal internalization positively correlated with conscientiousness, and both thin- and athletic-ideal internalization were positively related to extraversion. After controlling for gender, body mass index, the other appearance-ideal internalization, and the remaining personality traits, the indirect effects of both neuroticism and extraversion on body dissatisfaction through thin-ideal internalization were significant. Extraversion and conscientiousness were indirectly related to compulsive exercise through athletic-ideal internalization, whereas the indirect effect of neuroticism was dependent on covariates. As such, personality traits may be related to

Computations of ideal and real gas high altitude plume flows

NASA Technical Reports Server (NTRS)

Feiereisen, William J.; Venkatapathy, Ethiraj

1988-01-01

In the present work, complete flow fields around generic space vehicles in supersonic and hypersonic flight regimes are studied numerically. Numerical simulation is performed with a flux-split, time asymptotic viscous flow solver that incorporates a generalized equilibrium chemistry model. Solutions to generic problems at various altitude and flight conditions show the complexity of the flow, the equilibrium chemical dissociation and its effect on the overall flow field. Viscous ideal gas solutions are compared against equilibrium gas solutions to illustrate the effect of equilibrium chemistry. Improved solution accuracy is achieved through adaptive grid refinement.

Effect of fluid-colloid interactions on the mobility of a thermophoretic microswimmer in non-ideal fluids.

PubMed

Fedosov, Dmitry A; Sengupta, Ankush; Gompper, Gerhard

2015-09-07

Janus colloids propelled by light, e.g., thermophoretic particles, offer promising prospects as artificial microswimmers. However, their swimming behavior and its dependence on fluid properties and fluid-colloid interactions remain poorly understood. Here, we investigate the behavior of a thermophoretic Janus colloid in its own temperature gradient using numerical simulations. The dissipative particle dynamics method with energy conservation is used to investigate the behavior in non-ideal and ideal-gas like fluids for different fluid-colloid interactions, boundary conditions, and temperature-controlling strategies. The fluid-colloid interactions appear to have a strong effect on the colloid behavior, since they directly affect heat exchange between the colloid surface and the fluid. The simulation results show that a reduction of the heat exchange at the fluid-colloid interface leads to an enhancement of colloid's thermophoretic mobility. The colloid behavior is found to be different in non-ideal and ideal fluids, suggesting that fluid compressibility plays a significant role. The flow field around the colloid surface is found to be dominated by a source-dipole, in agreement with the recent theoretical and simulation predictions. Finally, different temperature-control strategies do not appear to have a strong effect on the colloid's swimming velocity.

Using Solution-Focused Intervention for Behavioral Problems in an Inclusive Classroom.

ERIC Educational Resources Information Center

Quigney, Theresa A.; Studer, Jeannine R.

1999-01-01

Solution-focused intervention deviates from using negative labels (angry, aggressive, or shy) to describe misbehaving students, and reframes behavior descriptions more positively. Four steps (goal setting, looking for exceptions, visualizing a new life story, and practicing the desired behaviors) are vital to facilitating positive behavior…

The Decisions of Elementary School Principals: A Test of Ideal Type Methodology.

ERIC Educational Resources Information Center

Greer, John T.

Interviews with 25 Georgia elementary school principals provided data that could be used to test an application of Max Weber's ideal type methodology to decision-making. Alfred Schuetz's model of the rational act, based on one of Weber's ideal types, was analyzed and translated into describable acts and behaviors. Interview procedures were…

Non-ideal magnetohydrodynamics on a moving mesh

NASA Astrophysics Data System (ADS)

Marinacci, Federico; Vogelsberger, Mark; Kannan, Rahul; Mocz, Philip; Pakmor, Rüdiger; Springel, Volker

2018-05-01

In certain astrophysical systems, the commonly employed ideal magnetohydrodynamics (MHD) approximation breaks down. Here, we introduce novel explicit and implicit numerical schemes of ohmic resistivity terms in the moving-mesh code AREPO. We include these non-ideal terms for two MHD techniques: the Powell 8-wave formalism and a constrained transport scheme, which evolves the cell-centred magnetic vector potential. We test our implementation against problems of increasing complexity, such as one- and two-dimensional diffusion problems, and the evolution of progressive and stationary Alfvén waves. On these test problems, our implementation recovers the analytic solutions to second-order accuracy. As first applications, we investigate the tearing instability in magnetized plasmas and the gravitational collapse of a rotating magnetized gas cloud. In both systems, resistivity plays a key role. In the former case, it allows for the development of the tearing instability through reconnection of the magnetic field lines. In the latter, the adopted (constant) value of ohmic resistivity has an impact on both the gas distribution around the emerging protostar and the mass loading of magnetically driven outflows. Our new non-ideal MHD implementation opens up the possibility to study magneto-hydrodynamical systems on a moving mesh beyond the ideal MHD approximation.

Microeconomics of the ideal gas like market models

NASA Astrophysics Data System (ADS)

Chakrabarti, Anindya S.; Chakrabarti, Bikas K.

2009-10-01

We develop a framework based on microeconomic theory from which the ideal gas like market models can be addressed. A kinetic exchange model based on that framework is proposed and its distributional features have been studied by considering its moments. Next, we derive the moments of the CC model (Eur. Phys. J. B 17 (2000) 167) as well. Some precise solutions are obtained which conform with the solutions obtained earlier. Finally, an output market is introduced with global price determination in the model with some necessary modifications.

Diffusion behavior of lipid vesicles in entangled polymer solutions.

PubMed Central

Cao, X; Bansil, R; Gantz, D; Moore, E W; Niu, N; Afdhal, N H

1997-01-01

Dynamic light scattering was used to follow the tracer diffusion of phospholipid/cholesterol vesicles in aqueous polyacrylamide solutions and compared with the diffusive behavior of polystyrene (PS) latex spheres of comparable diameters. Over the range of the matrix concentration examined (Cp = 0.1-10 mg/ml), the diffusivities of the PS spheres and the large multilamellar vesicles exhibited the Stokes-Einstein (SE) relation, while the diffusivity of the unilamellar vesicles did not follow the increase of the solution's viscosity caused by the presence of the matrix molecules. The difference between the diffusion behaviors of unilamellar vesicles and hard PS spheres of similar size is possibly due to the flexibility of the lipid bilayer of the vesicles. The unilamellar vesicles are capable of changing their shape to move through the entangled polymer solution so that the hindrance to their diffusion due to the presence of the polymer chains is reduced, while the rigid PS spheres have little flexibility and they encounter greater resistance. The multilamellar vesicles are less flexible, thus their diffusion is similar to the hard PS spheres of similar diameter. Images FIGURE 2 PMID:9336189

Sex Education and Ideals

ERIC Educational Resources Information Center

de Ruyter, Doret J.; Spiecker, Ben

2008-01-01

This article argues that sex education should include sexual ideals. Sexual ideals are divided into sexual ideals in the strict sense and sexual ideals in the broad sense. It is argued that ideals that refer to the context that is deemed to be most ideal for the gratification of sexual ideals in the strict sense are rightfully called sexual…

Using NMR to Determine the Boiling Point Diagram for a Non-Ideal Solution

ERIC Educational Resources Information Center

Allen, Fritz S.; And Others

1975-01-01

Describes an experiment that enables the student to concentrate on the fundamentals of the non-ideal liquid-vapor equilibrium. Presents typical student data and suggests features which might be added to the experiment. (GS)

Differential molar heat capacities to test ideal solubility estimations.

PubMed

Neau, S H; Bhandarkar, S V; Hellmuth, E W

1997-05-01

Calculation of the ideal solubility of a crystalline solute in a liquid solvent requires knowledge of the difference in the molar heat capacity at constant pressure of the solid and the supercooled liquid forms of the solute, delta Cp. Since this parameter is not usually known, two assumptions have been used to simplify the expression. The first is that delta Cp can be considered equal to zero; the alternate assumption is that the molar entropy of fusion, delta Sf, is an estimate of delta Cp. Reports claiming the superiority of one assumption over the other, on the basis of calculations done using experimentally determined parameters, have appeared in the literature. The validity of the assumptions in predicting the ideal solubility of five structurally unrelated compounds of pharmaceutical interest, with melting points in the range 420 to 470 K, was evaluated in this study. Solid and liquid heat capacities of each compound near its melting point were determined using differential scanning calorimetry. Linear equations describing the heat capacities were extrapolated to the melting point to generate the differential molar heat capacity. Linear data were obtained for both crystal and liquid heat capacities of sample and test compounds. For each sample, ideal solubility at 298 K was calculated and compared to the two estimates generated using literature equations based on the differential molar heat capacity assumptions. For the compounds studied, delta Cp was not negligible and was closer to delta Sf than to zero. However, neither of the two assumptions was valid for accurately estimating the ideal solubility as given by the full equation.

Developmental Idealism and Cultural Models of the Family in Malawi

PubMed Central

Pierotti, Rachael S.; Young-DeMarco, Linda; Watkins, Susan

2014-01-01

This paper examines the extent to which developmental idealism has been disseminated in Malawi. Developmental idealism is a set of beliefs and values about development and the relationships between development and family structures and behavior. Developmental idealism states that attributes of societies and families defined as modern are better than attributes defined as traditional, that modern societies help produce modern families, that modern families facilitate the achievement of modern societies, and that the future will bring family change in the direction of modernity. Previous research has demonstrated that knowledge of developmental idealism is widespread in many places around the world, but provides little systematic data about it in sub-Saharan Africa or how knowledge of it is associated with certain demographic characteristics in that region. In this paper, we address this issue by examining whether ordinary people in two settings in Malawi, a sub-Saharan African country, have received and understood messages that are intended to associate development with certain types of family forms and family behaviors. We then examine associations between demographic characteristics and developmental idealism to investigate possible mechanisms linking global discourse about development to the grassroots. We analyze data collected in face-to-face surveys from two samples of Malawian men in 2009 and 2010, one rural, the other in a low-to-medium income neighborhood of a city. Our analysis of these survey data shows considerable evidence that many developmental idealism beliefs have been spread in that country and that education has positive effects on beliefs in the association between development and family attributes. We also find higher levels of developmental idealism awareness in the urban sample than we do in the rural sample, but once dissimilarities in education and wealth between the two samples are controlled, awareness levels no longer differed between

Physicochemical, bioactive, and sensory properties of persimmon-based ice cream: technique for order preference by similarity to ideal solution to determine optimum concentration.

PubMed

Karaman, Safa; Toker, Ömer Said; Yüksel, Ferhat; Çam, Mustafa; Kayacier, Ahmed; Dogan, Mahmut

2014-01-01

In the present study, persimmon puree was incorporated into the ice cream mix at different concentrations (8, 16, 24, 32, and 40%) and some physicochemical (dry matter, ash, protein, pH, sugar, fat, mineral, color, and viscosity), textural (hardness, stickiness, and work of penetration), bioactive (antiradical activity and total phenolic content), and sensory properties of samples were investigated. The technique for order preference by similarity to ideal solution approach was used for the determination of optimum persimmon puree concentration based on the sensory and bioactive characteristics of final products. Increase in persimmon puree resulted in a decrease in the dry matter, ash, fat, protein contents, and viscosity of ice cream mix. Glucose, fructose, sucrose, and lactose were determined to be major sugars in the ice cream samples including persimmon and increase in persimmon puree concentration increased the fructose and glucose content. Better melting properties and textural characteristics were observed for the samples with the addition of persimmon. Magnesium, K, and Ca were determined to be major minerals in the samples and only K concentration increased with the increase in persimmon content. Bioactive properties of ice cream samples improved and, in general, acetone-water extracts showed higher bioactivity compared with ones obtained using methanol-water extracts. The technique for order preference by similarity to ideal solution approach showed that the most preferred sample was the ice cream containing 24% persimmon puree. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Structural arrest in an ideal gas.

PubMed

van Ketel, Willem; Das, Chinmay; Frenkel, Daan

2005-04-08

We report a molecular dynamics study of a simple model system that has the static properties of an ideal gas, yet exhibits nontrivial "glassy" dynamics behavior at high densities. The constituent molecules of this system are constructs of three infinitely thin hard rods of length L, rigidly joined at their midpoints. The crosses have random but fixed orientation. The static properties of this system are those of an ideal gas, and its collision frequency can be computed analytically. For number densities NL(3)/V>1, the single-particle diffusivity goes to zero. As the system is completely structureless, standard mode-coupling theory cannot describe the observed structural arrest. Nevertheless, the system exhibits many dynamical features that appear to be mode-coupling-like. All high-density incoherent intermediate scattering functions collapse onto master curves that depend only on the wave vector.

Childhood Lifestyle and Clinical Determinants of Adult Ideal

PubMed Central

Laitinen, Tomi T.; Pahkala, Katja; Venn, Alison; Woo, Jessica G; Oikonen, Mervi; Dwyer, Terence; Mikkilä, Vera; Hutri-Kähönen, Nina; Smith, Kylie J.; Gall, Seana L.; Morrison, John A.; Viikari, Jorma S.A.; Raitakari, Olli T.; Magnussen, Costan G.; Juonala, Markus

2013-01-01

Background The American Heart Association recently defined ideal cardiovascular health by simultaneous presence of seven health behaviors and factors. The concept is associated with cardiovascular disease incidence, and cardiovascular disease and all-cause mortality. To effectively promote ideal cardiovascular health already early in life, childhood factors predicting future ideal cardiovascular health should be investigated. Our aim was thus to comprehensively explore childhood determinants of adult ideal cardiovascular health in population based cohorts from three continents. Methods The sample comprised a total of 4409 participants aged 3–19 years at baseline from the Cardiovascular Risk in Young Finns Study (YFS; N=1883) from Finland, Childhood Determinants of Adult Health Study (CDAH; N=1803) from Australia and Princeton Follow-up Study (PFS; N=723) from the United States. Participants were re-examined 19–31 years later when aged 30–48 years. Results In multivariable analyses, independent childhood predictors of adult ideal cardiovascular health were family socioeconomic status (P<0.01; direct association) and BMI (P<0.001; inverse association) in all cohorts. In addition, blood pressure (P=0.007), LDL-cholesterol (P<0.001) and parental smoking (P=0.006) in the YFS, and own smoking (P=0.001) in CDAH were inversely associated with future ideal cardiovascular health. Conclusions Among several lifestyle and clinical indicators studied, higher family socioeconomic status and non-smoking (parental/own) in childhood independently predict ideal cardiovascular health in adulthood. As atherosclerotic cardiovascular diseases are rooted in childhood, our findings suggest that special attention could be paid to children who are from low socioeconomic status families, and who smoke or whose parents smoke, to prevent cardiovascular disease morbidity and mortality. PMID:24075574

An exact solution for the history-dependent material and delamination behavior of laminated plates subjected to cylindrical bending

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Todd O

2009-01-01

The exact solution for the history-dependent behavior of laminated plates subjected to cylindrical bending is presented. The solution represents the extension of Pagano's solution to consider arbitrary types of constitutive behaviors for the individual lamina as well as arbitrary types of cohesive zones models for delamination behavior. Examples of the possible types of material behavior are plasticity, viscoelasticity, viscoplasticity, and damaging. Examples of possible CZMs that can be considered are linear, nonlinear hardening, as well as nonlinear with softening. The resulting solution is intended as a benchmark solution for considering the predictive capabilities of different plate theories. Initial results aremore » presented for several types of history-dependent material behaviors. It is shown that the plate response in the presence of history-dependent behaviors can differ dramatically from the elastic response. These results have strong implications for what constitutes an appropriate plate theory for modeling such behaviors.« less

Discrepancies between perceptions of real and ideal yoga teachers and their relationship to emotional well-being.

PubMed

Park, Crystal L; Riley, Kristen E; Besedin, Elena Y; Stewart, V Michelle

2013-01-01

Although more individuals are adopting yoga into their lives, little research has examined practitioners' expectations and experiences of their yoga instructor's behavior. Discrepancies between real and ideal behaviors of yoga instructors may lead to unsatisfactory experiences and decrease the potential impact of yoga practice. This study investigated differences between yoga practitioners' real and ideal perceptions of their yoga teacher's behavior and the relationship between discrepant beliefs and students' symptoms of depression, anxiety,and stress. The Perceptions of Yoga Teacher Questionnaire (PYTQ), a recently developed survey of student attitudes regarding yoga teachers' behavior, was administered ina national online survey of yoga students and teachers. Greater discrepancy between real and idea yoga teacher behavior was anticipated to be positively associated with practitioners' symptoms of depression, anxiety, and stress. Pearson correlations corrected for multiple comparisons revealed that yoga students and teachers are generally satisfied with their teacher's behaviors. Significant discrepancies between real and ideal teacher behavior were found for both groups. Higher discrepancy scores were associated with symptoms of stress and anxiety but not depression for students, but not for teachers. These preliminary findings provide insight into the relationship between expectancies and real yoga teacher behaviors and their links to student emotional adjustment.More research in this area is warranted.

Buffered lidocaine and bupivacaine mixture - the ideal local anesthetic solution?

PubMed

Best, Corliss A; Best, Alyssa A; Best, Timothy J; Hamilton, Danielle A

2015-01-01

The use of injectable local anesthetic solutions to facilitate pain-free surgery is an integral component of many procedures performed by the plastic surgeon. In many instances, a solution that has both rapid onset and prolonged duration of analgesia is optimal. A combination of lidocaine and bupivacaine, plain or with epinephrine, is readily available in most Canadian health care settings where such procedures are performed, and fulfills these criteria. However, commercially available solutions of both medications are acidic and cause a burning sensation on injection. Buffering to neutral pH with sodium bicarbonate is a practical method to mitigate the burning sensation, and has the added benefit of increasing the fraction of nonionized lipid soluble drug available. The authors report on the proportions of the three drugs to yield a neutral pH, and the results of an initial survey regarding the use of the combined solution with epinephrine in hand surgery.

Ideal strength of bcc molybdenum and niobium

NASA Astrophysics Data System (ADS)

Luo, Weidong; Roundy, D.; Cohen, Marvin L.; Morris, J. W.

2002-09-01

The behavior of bcc Mo and Nb under large strain was investigated using the ab initio pseudopotential density-functional method. We calculated the ideal shear strength for the {211}<111> and {011}<111> slip systems and the ideal tensile strength in the <100> direction, which are believed to provide the minimum shear and tensile strengths. As either material is sheared in either of the two systems, it evolves toward a stress-free tetragonal structure that defines a saddle point in the strain-energy surface. The inflection point on the path to this tetragonal ``saddle-point'' structure sets the ideal shear strength. When either material is strained in tension along <100>, it initially follows the tetragonal, ``Bain,'' path toward a stress-free fcc structure. However, before the strained crystal reaches fcc, its symmetry changes from tetragonal to orthorhombic; on continued strain it evolves toward the same tetragonal saddle point that is reached in shear. In Mo, the symmetry break occurs after the point of maximum tensile stress has been passed, so the ideal strength is associated with the fcc extremum as in W. However, a Nb crystal strained in <100> becomes orthorhombic at tensile stress below the ideal strength. The ideal tensile strength of Nb is associated with the tetragonal saddle point and is caused by failure in shear rather than tension. In dimensionless form, the ideal shear and tensile strengths of Mo (τ*=τm/G111=0.12, σ*=σm/E100=0.078) are essentially identical to those previously calculated for W. Nb is anomalous. Its dimensionless shear strength is unusually high, τ*=0.15, even though the saddle-point structure that causes it is similar to that in Mo and W, while its dimensionless tensile strength, σ*=0.079, is almost the same as that of Mo and W, even though the saddle-point structure is quite different.

Detecting the Biopolymer Behavior of Graphene Nanoribbons in Aqueous Solution

NASA Astrophysics Data System (ADS)

Li, Jingqiang; Wijeratne, Sithara; Penev, Evgeni; Lu, Wei; Duque, Amanda; Yakobson, Boris; Tour, James; Kiang, Ching-Hwa; Boris I. Yakobson Group Team; James M. Tour Group Team; Ching-Hwa Kiang Group Team

Graphene nanoribbons (GNR), can be prepared in bulk quantities for large-area applications by reducing the product from the lengthwise oxidative unzipping of multiwalled carbon nanotubes (MWNT). Recently, the biomaterials application of GNR has been explored, for example, in the pore to be used for DNA sequencing. Therefore, understanding the polymer behavior of GNR in solution is essential in predicting GNR interaction with biomaterials. Here, we report experimental studies of the solutionbased mechanical properties of GNR and their parent products, graphene oxide nanoribbons (GONR). We used atomic force microscopy (AFM) to study their mechanical properties in solution and showed that GNR and GONR have similar force-extension behavior as in biopolymers such as proteins and DNA. The rigidity increases with reducing chemical functionalities. The similarities in rigidity and tunability between nanoribbons and biomolecules might enable the design and fabrication of GNR-biomimetic interfaces.

Complicated asymptotic behavior of solutions for porous medium equation in unbounded space

NASA Astrophysics Data System (ADS)

Wang, Liangwei; Yin, Jingxue; Zhou, Yong

2018-05-01

In this paper, we find that the unbounded spaces Yσ (RN) (0 < σ <2/m-1 ) can provide the work spaces where complicated asymptotic behavior appears in the solutions of the Cauchy problem of the porous medium equation. To overcome the difficulties caused by the nonlinearity of the equation and the unbounded solutions, we establish the propagation estimates, the growth estimates and the weighted L1-L∞ estimates for the solutions.

An Ideal Observer Analysis of Visual Working Memory

ERIC Educational Resources Information Center

Sims, Chris R.; Jacobs, Robert A.; Knill, David C.

2012-01-01

Limits in visual working memory (VWM) strongly constrain human performance across many tasks. However, the nature of these limits is not well understood. In this article we develop an ideal observer analysis of human VWM by deriving the expected behavior of an optimally performing but limited-capacity memory system. This analysis is framed around…

Variational Integration for Ideal Magnetohydrodynamics and Formation of Current Singularities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Yao

Coronal heating has been a long-standing conundrum in solar physics. Parker's conjecture that spontaneous current singularities lead to nanoflares that heat the corona has been controversial. In ideal magnetohydrodynamics (MHD), can genuine current singularities emerge from a smooth 3D line-tied magnetic field? To numerically resolve this issue, the schemes employed must preserve magnetic topology exactly to avoid artificial reconnection in the presence of (nearly) singular current densities. Structure-preserving numerical methods are favorable for mitigating numerical dissipation, and variational integration is a powerful machinery for deriving them. However, successful applications of variational integration to ideal MHD have been scarce. In thismore » thesis, we develop variational integrators for ideal MHD in Lagrangian labeling by discretizing Newcomb's Lagrangian on a moving mesh using discretized exterior calculus. With the built-in frozen-in equation, the schemes are free of artificial reconnection, hence optimal for studying current singularity formation. Using this method, we first study a fundamental prototype problem in 2D, the Hahm-Kulsrud-Taylor (HKT) problem. It considers the effect of boundary perturbations on a 2D plasma magnetized by a sheared field, and its linear solution is singular. We find that with increasing resolution, the nonlinear solution converges to one with a current singularity. The same signature of current singularity is also identified in other 2D cases with more complex magnetic topologies, such as the coalescence instability of magnetic islands. We then extend the HKT problem to 3D line-tied geometry, which models the solar corona by anchoring the field lines in the boundaries. The effect of such geometry is crucial in the controversy over Parker's conjecture. The linear solution, which is singular in 2D, is found to be smooth. However, with finite amplitude, it can become pathological above a critical system length. The

Ideal Cardiovascular Health and Arterial Stiffness in Spanish Adults-The EVIDENT Study.

PubMed

García-Hermoso, Antonio; Martínez-Vizcaíno, Vicente; Gomez-Marcos, Manuel Ángel; Cavero-Redondo, Iván; Recio-Rodriguez, José Ignacio; García-Ortiz, Luis

2018-05-01

Studies concerning ideal cardiovascular (CV) health and its relationship with arterial stiffness are lacking. This study examined the association between arterial stiffness with ideal CV health as defined by the American Heart Association, across age groups and gender. The cross-sectional study included 1365 adults. Ideal CV health was defined as meeting ideal levels of the following components: 4 behaviors (smoking, body mass index, physical activity, and Mediterranean diet adherence) and 3 factors (total cholesterol, blood pressure, and glycated hemoglobin). Patients were grouped into 3 categories according to their number of ideal CV health metrics: ideal (5-7 metrics), intermediate (3-4 metrics), and poor (0-2 metrics). We analyzed the pulse wave velocity (PWV), the central and radial augmentation indexes, and the ambulatory arterial stiffness index (AASI). The ideal CV health profile was inversely associated with lower arterial radial augmentation index and AASI in both genders, particularly in middle-aged (45-65 years) and in elderly subjects (>65 years). Also in elderly subjects, adjusted models showed that adults with at least 3 health metrics at ideal levels had significantly lower PWV than those with 2 or fewer ideal health metrics. An association was found between a favorable level of ideal CV health metrics and lower arterial stiffness across age groups. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Effect of concentration and temperature on the rheological behavior of collagen solution.

PubMed

Lai, Guoli; Li, Yang; Li, Guoying

2008-04-01

Dynamic viscoelastic properties of collagen solutions with concentrations of 0.5-1.5% (w/w) were characterized by means of oscillatory rheometry at temperatures ranging from 20 to 32.5 degrees C. All collagen solutions showed a shear-thinning flow behavior. The complex viscosity exhibited an exponential increase and the loss tangent decreased with the increase of collagen concentration (C(COL)) when the C(COL)> or =0.75%. Both storage modulus (G') and loss modulus (G'') increased with the increase of frequency and concentration, but decreased with the increase of temperature and behaved without regularity at 32.5 degrees C. The relaxation times decreased with the increase of temperature for 1.0% collagen solution. According to a three-zone model, dynamic modulus of collagen solutions showed terminal-zone and plateau-zone behavior when C(COL) was no more than 1.25% or the stated temperature was no more than 30 degrees C. The concentrated solution (1.5%) behaved being entirely in plateau zone. An application of the time-temperature superposition (TTS) allowed the construction of master curve and an Arrhenius-type TTS principle was used to yield the activation energy of 161.4 kJ mol(-1).

Effect of tritium on corrosion behavior of chromium in 0.01 N sulfuric acid solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oyaidzu, M.; Isobe, K.; Hayashi, T.

The effects of tritium on the corrosion behavior of chromium in 0.01 N sulfuric solution have been investigated in the present study. Electrochemical experiments have been carried our for pure chromium. At first, the concentration dependence of sulfuric acid solution on anodic polarization behavior of chromium was experimented, resulting in that 0.01 N one was found appropriate. The dependence of both dissolved oxygen and tritium concentration on anodic behavior of chromium were performed. It was found from that the self-passivation of chromium induced by dissolved oxygen was inhibited in tritiated solution resulting in the enhancement of the corrosion. As amore » consequence it is highly likely that the elution of chromium by highly oxidative radiolysis products would explain the passivation inhibitory effect of SUS304 stainless steel observed in tritiated solutions.« less

Asymptotic Behavior of Solutions of Systems of Neutral and Convolution Equations

NASA Astrophysics Data System (ADS)

Basit, Bolis; Günzler, Hans

1998-10-01

Suppose J=[α, ∞) for someα∈R or J=R and letXbe a Banach space. We study asymptotic behavior of solutions on J of neutral system of equations with values inX. This reduces to questions concerning the behavior of solutions of convolution equations (*)H∗Ω=b, whereH=(Hj, k) is anr×rmatrix,Hj, k∈D‧L1,b=(bj) andbj∈D‧(R, X), for 1⩽j, k⩽r. We prove that ifΩis a bounded uniformly continuous solution of (*) withbfrom some translation invariant suitably closed class A, thenΩbelongs to A, provided, for example, that det Hhas countably many zeros on R andc0⊄X. In particular, ifbis (asymptotically) almost periodic, almost automorphic or recurrent,Ωis too. Our results extend theorems of Bohr, Neugebauer, Bochner, Doss, Basit, and Zhikov and also, certain theorems of Fink, Madych, Staffans, and others. Also, we investigate bounded solutions of (*). This leads to an extension of the known classes of almost periodicity to larger classes called mean-classes. We explore mean-classes and prove that bounded solutions of (*) belong to mean-classes provided certain conditions hold. These results seem new even for the simplest difference equationΩ(t+1)-Ω(t)=b(t) with J=X=R andbStepanoff almost periodic.

Finite-Difference Solution for Laminar or Turbulent Boundary Layer Flow over Axisymmetric Bodies with Ideal Gas, CF4, or Equilibrium Air Chemistry

NASA Technical Reports Server (NTRS)

Hamilton, H. Harris, II; Millman, Daniel R.; Greendyke, Robert B.

1992-01-01

A computer code was developed that uses an implicit finite-difference technique to solve nonsimilar, axisymmetric boundary layer equations for both laminar and turbulent flow. The code can treat ideal gases, air in chemical equilibrium, and carbon tetrafluoride (CF4), which is a useful gas for hypersonic blunt-body simulations. This is the only known boundary layer code that can treat CF4. Comparisons with experimental data have demonstrated that accurate solutions are obtained. The method should prove useful as an analysis tool for comparing calculations with wind tunnel experiments and for making calculations about flight vehicles where equilibrium air chemistry assumptions are valid.

Finite-difference solution for laminar or turbulent boundary layer flow over axisymmetric bodies with ideal gas, CF4, or equilibrium air chemistry

NASA Astrophysics Data System (ADS)

Hamilton, H. Harris, II; Millman, Daniel R.; Greendyke, Robert B.

1992-12-01

A computer code was developed that uses an implicit finite-difference technique to solve nonsimilar, axisymmetric boundary layer equations for both laminar and turbulent flow. The code can treat ideal gases, air in chemical equilibrium, and carbon tetrafluoride (CF4), which is a useful gas for hypersonic blunt-body simulations. This is the only known boundary layer code that can treat CF4. Comparisons with experimental data have demonstrated that accurate solutions are obtained. The method should prove useful as an analysis tool for comparing calculations with wind tunnel experiments and for making calculations about flight vehicles where equilibrium air chemistry assumptions are valid.

A new shock-capturing numerical scheme for ideal hydrodynamics

NASA Astrophysics Data System (ADS)

Fecková, Z.; Tomášik, B.

2015-05-01

We present a new algorithm for solving ideal relativistic hydrodynamics based on Godunov method with an exact solution of Riemann problem for an arbitrary equation of state. Standard numerical tests are executed, such as the sound wave propagation and the shock tube problem. Low numerical viscosity and high precision are attained with proper discretization.

Calcium leaching behavior of cementitious materials in hydrochloric acid solution.

PubMed

Yang, Huashan; Che, Yujun; Leng, Faguang

2018-06-11

The calcium leaching behavior of cement paste and silica fume modified calcium hydroxide paste, exposed to hydrochloric acid solution, is reported in this paper. The kinetic of degradation was assessed by the changes of pH of hydrochloric acid solution with time. The changes of compressive strength of specimens in hydrochloric acid with time were tested. Hydration products of leached specimens were also analyzed by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric (TG), and atomic force microscope (AFM). Tests results show that there is a dynamic equilibrium in the supply and consumption of calcium hydroxide in hydrochloric acid solution, which govern the stability of hydration products such as calcium silicate hydrate (C-S-H). The decrease of compressive strength indicates that C-S-H are decomposed due to the lower concentration of calcium hydroxide in the pore solution than the equilibrium concentration of the hydration products. Furthermore, the hydration of unhydrated clinker delayed the decomposition of C-S-H in hydrochloric acid solution due to the increase of calcium hydroxide in pore solution of cementitious materials.

Knop's Solution Is Not What It Seems.

ERIC Educational Resources Information Center

Hershey, David R.

2001-01-01

Discusses Knob's solution, which was considered the ideal plant growth solution in 1865, and recommends eliminating Knob's solution from active teaching. Describes solution culture basics including nutrient solutions, containers and aeration, and plants and light. (Contains 12 references.) (YDS)

Ideals versus reality: Are weight ideals associated with weight change in the population?

PubMed

Kärkkäinen, Ulla; Mustelin, Linda; Raevuori, Anu; Kaprio, Jaakko; Keski-Rahkonen, Anna

2016-04-01

To quantify weight ideals of young adults and to examine whether the discrepancy between actual and ideal weight is associated with 10-year body mass index (BMI) change in the population. This study comprised 4,964 adults from the prospective population-based FinnTwin16 study. They reported their actual and ideal body weight at age 24 (range 22-27) and 10 years later (attrition 24.6%). The correlates of discrepancy between actual and ideal body weight and the impact on subsequent BMI change were examined. The discrepancy between actual and ideal weight at 24 years was on average 3.9 kg (1.4 kg/m(2) ) among women and 1.2 kg (0.4 kg/m(2) ) among men. On average, participants gained weight during follow-up irrespective of baseline ideal weight: women ¯x = +4.8 kg (1.7 kg/m(2) , 95% CI 1.6-1.9 kg/m(2) ), men ¯x = +6.3 kg (2.0 kg/m(2) , 95% CI 1.8-2.1 kg/m(2) ). Weight ideals at 24 years were not correlated with 10-year weight change. At 34 years, just 13.2% of women and 18.9% of men were at or below the weight they had specified as their ideal weight at 24 years. Women and men adjusted their ideal weight upward over time. Irrespective of ideal weight at baseline, weight gain was nearly universal. Weight ideals were shifted upward over time. © 2016 The Obesity Society.

Osmosis and thermodynamics explained by solute blocking.

PubMed

Nelson, Peter Hugo

2017-01-01

A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.

Osmosis and thermodynamics explained by solute blocking

PubMed Central

Nelson, Peter Hugo

2016-01-01

A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult’s law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed, others can be tested experimentally or by simulation. PMID:27225298

(Fuzzy) Ideals of BN-Algebras

PubMed Central

Walendziak, Andrzej

2015-01-01

The notions of an ideal and a fuzzy ideal in BN-algebras are introduced. The properties and characterizations of them are investigated. The concepts of normal ideals and normal congruences of a BN-algebra are also studied, the properties of them are displayed, and a one-to-one correspondence between them is presented. Conditions for a fuzzy set to be a fuzzy ideal are given. The relationships between ideals and fuzzy ideals of a BN-algebra are established. The homomorphic properties of fuzzy ideals of a BN-algebra are provided. Finally, characterizations of Noetherian BN-algebras and Artinian BN-algebras via fuzzy ideals are obtained. PMID:26125050

A matrix solution for the simulation of magnetic fields with ideal current loops

NASA Technical Reports Server (NTRS)

Stankiewicz, N.

1979-01-01

A matrix formulation is presented for describing axisymmetric magnetic field data with ideal current loops. A computer program written in APL is used to invert the matrix and hence to solve for the coil strengths which are used to represent the field data. Examples are given of the coil representation for (1) measured magnetic data, (2) refocusing fields, and (3) PPM focusing fields.

Corrosion behavior of stainless steel weldments in physiological solutions

NASA Astrophysics Data System (ADS)

Farooq, A.; Azam, M.; Deen, K. M.

2018-01-01

In this study corrosion behavior of TIG welded 316L stainless steel plates in simulated biological solutions is investigated. The mechanical testing results showed slight decrease in ductility after welding and the fracture surface represented mixed cleavage and inclusions containing dimple structure. The heat affected and weld zone (WZ) demonstrated higher corrosion potential and relatively large pitting tendency than base metal (BM) in both Hank’s and Ringer’s solution. The formation of delta (δ) ferrite in the heat affected and WZ decreased the corrosion resistance as confirmed from potentiodynamic Tafel scans. The decrease in pitting resistance and lower protection tendency of the WZ compared to BM and heat affected zone was also quantified from the cyclic polarization trends.

On the Ethics of Teaching and the Ideals of Learning.

ERIC Educational Resources Information Center

Audi, Robert

1994-01-01

The author argues that ethical college teaching requires that teachers focus on ideals: goals and aspirations reaching beyond merely correct behavior that satisfies basic moral requirements. This includes the obligation to be professionally competent, fair in grading, fair in making recommendations, and fair to their colleagues. (MSE)

Conical flow near singular rays. [shock generation in ideal gas

NASA Technical Reports Server (NTRS)

Zahalak, G. I.; Myers, M. K.

1974-01-01

The steady flow of an ideal gas past a conical body is investigated by the method of matched asymptotic expansions, with particular emphasis on the flow near the singular ray occurring in linearized theory. The first-order problem governing the flow in this region is formulated, leading to the equation of Kuo, and an approximate solution is obtained in the case of compressive flow behind the main front. This solution is compared with the results of previous investigations with a view to assessing the applicability of the Lighthill-Whitham theories.

Real-gas effects 1: Simulation of ideal gas flow by cryogenic nitrogen and other selected gases

NASA Technical Reports Server (NTRS)

Hall, R. M.

1980-01-01

The thermodynamic properties of nitrogen gas do not thermodynamically approximate an ideal, diatomic gas at cryogenic temperatures. Choice of a suitable equation of state to model its behavior is discussed and the equation of Beattie and Bridgeman is selected as best meeting the needs for cryogenic wind tunnel use. The real gas behavior of nitrogen gas is compared to an ideal, diatomic gas for the following flow processes: isentropic expansion; normal shocks; boundary layers; and shock wave boundary layer interactions. The only differences in predicted pressure ratio between nitrogen and an ideal gas that may limit the minimum operating temperatures of transonic cryogenic wind tunnels seem to occur at total pressures approaching 9atmospheres and total temperatures 10 K below the corresponding saturation temperature, where the differences approach 1 percent for both isentropic expansions and normal shocks. Several alternative cryogenic test gases - air, helium, and hydrogen - are also analyzed. Differences in air from an ideal, diatomic gas are similar in magnitude to those of nitrogen. Differences for helium and hydrogen are over an order of magnitude greater than those for nitrogen or air. Helium and hydrogen do not approximate the compressible flow of an ideal, diatomic gas.

Enabling Surgical Placement of Hydrogels through Achieving Paste-Like Rheological Behavior in Hydrogel Precursor Solutions

PubMed Central

Beck, Emily C.; Lohman, Brooke L.; Tabakh, Daniel B.; Kieweg, Sarah L.; Gehrke, Stevin H.; Berkland, Cory J.; Detamore, Michael S.

2015-01-01

Hydrogels are a promising class of materials for tissue regeneration, but they lack the ability to be molded into a defect site by a surgeon because hydrogel precursors are liquid solutions that are prone to leaking during placement. Therefore, although the main focus of hydrogel technology and developments are on hydrogels in their crosslinked form, our primary focus is on improving the fluid behavior of hydrogel precursor solutions. In this work, we introduce a method to achieve paste-like hydrogel precursor solutions by combining hyaluronic acid nanoparticles with traditional crosslinked hyaluronic acid hydrogels. Prior to crosslinking, the samples underwent rheological testing to assess yield stress and recovery using linear hyaluronic acid as a control. The experimental groups containing nanoparticles were the only solutions that exhibited a yield stress, demonstrating that the nanoparticulate rather than the linear form of hyaluronic acid was necessary to achieve paste-like behavior. The gels were also photocrosslinked and further characterized as solids, where it was demonstrated that the inclusion of nanoparticles did not adversely affect the compressive modulus and that encapsulated bone marrow-derived mesenchymal stem cells remained viable. Overall, this nanoparticle-based approach provides a platform hydrogel system that exhibits a yield stress prior to crosslinking, and can then be crosslinked into a hydrogel that is capable of encapsulating cells that remain viable. This behavior may hold significant impact for hydrogel applications where a paste-like behavior is desired in the hydrogel precursor solution. PMID:25691398

Provisional-Ideal-Point-Based Multi-objective Optimization Method for Drone Delivery Problem

NASA Astrophysics Data System (ADS)

Omagari, Hiroki; Higashino, Shin-Ichiro

2018-04-01

In this paper, we proposed a new evolutionary multi-objective optimization method for solving drone delivery problems (DDP). It can be formulated as a constrained multi-objective optimization problem. In our previous research, we proposed the "aspiration-point-based method" to solve multi-objective optimization problems. However, this method needs to calculate the optimal values of each objective function value in advance. Moreover, it does not consider the constraint conditions except for the objective functions. Therefore, it cannot apply to DDP which has many constraint conditions. To solve these issues, we proposed "provisional-ideal-point-based method." The proposed method defines a "penalty value" to search for feasible solutions. It also defines a new reference solution named "provisional-ideal point" to search for the preferred solution for a decision maker. In this way, we can eliminate the preliminary calculations and its limited application scope. The results of the benchmark test problems show that the proposed method can generate the preferred solution efficiently. The usefulness of the proposed method is also demonstrated by applying it to DDP. As a result, the delivery path when combining one drone and one truck drastically reduces the traveling distance and the delivery time compared with the case of using only one truck.

Propagation of exponential shock wave in an axisymmetric rotating non-ideal dusty gas

NASA Astrophysics Data System (ADS)

Nath, G.

2016-09-01

One-dimensional unsteady isothermal and adiabatic flow behind a strong exponential shock wave propagating in a rotational axisymmetric mixture of non-ideal gas and small solid particles, which has variable azimuthal and axial fluid velocities, is analyzed. The shock wave is driven out by a piston moving with time according to exponential law. The azimuthal and axial components of the fluid velocity in the ambient medium are assumed to be varying and obeying exponential laws. In the present work, small solid particles are considered as pseudo-fluid with the assumption that the equilibrium flow-conditions are maintained in the flow-field, and the viscous-stress and heat conduction of the mixture are negligible. Solutions are obtained in both the cases, when the flow between the shock and the piston is isothermal or adiabatic by taking into account the components of vorticity vector and compressibility. It is found that the assumption of zero temperature gradient brings a profound change in the density, axial component of vorticity vector and compressibility distributions as compared to that of the adiabatic case. To investigate the behavior of the flow variables and the influence on the shock wave propagation by the parameter of non-idealness of the gas overline{b} in the mixture as well as by the mass concentration of solid particles in the mixture Kp and by the ratio of the density of solid particles to the initial density of the gas G1 are worked out in detail. It is interesting to note that the shock strength increases with an increase in G1 ; whereas it decreases with an increase in overline{b} . Also, a comparison between the solutions in the cases of isothermal and adiabatic flows is made.

Developmental Idealism: The Cultural Foundations of World Development Programs

PubMed Central

Thornton, Arland; Dorius, Shawn F.; Swindle, Jeffrey

2015-01-01

This paper extends theory and research concerning cultural models of development beyond family and demographic matters to a broad range of additional factors, including government, education, human rights, daily social conventions, and religion. Developmental idealism is a cultural model—a set of beliefs and values—that identifies the appropriate goals of development and the ends for achieving these goals. It includes beliefs about positive cause and effect relationships among such factors as economic growth, educational achievement, health, and political governance, as well as strong values regarding many attributes, including economic growth, education, small families, gender equality, and democratic governance. This cultural model has spread from its origins among the elites of northwest Europe to elites and ordinary people throughout the world. Developmental idealism has become so entrenched in local, national, and global social institutions that it has now achieved a taken-for-granted status among many national elites, academics, development practitioners, and ordinary people around the world. We argue that developmental idealism culture has been a fundamental force behind many cultural clashes within and between societies, and continues to be an important cause of much global social change. We suggest that developmental idealism should be included as a causal factor in theories of human behavior and social change. PMID:26457325

Abstraction and Idealization in Biomedicine: The Nonautonomous Theory of Acute Cell Injury.

PubMed

DeGracia, Donald J; Taha, Doaa; Tri Anggraini, Fika; Sutariya, Shreya; Rababeh, Gabriel; Huang, Zhi-Feng

2018-02-27

Neuroprotection seeks to halt cell death after brain ischemia and has been shown to be possible in laboratory studies. However, neuroprotection has not been successfully translated into clinical practice, despite voluminous research and controlled clinical trials. We suggested these failures may be due, at least in part, to the lack of a general theory of cell injury to guide research into specific injuries. The nonlinear dynamical theory of acute cell injury was introduced to ameliorate this situation. Here we present a revised nonautonomous nonlinear theory of acute cell injury and show how to interpret its solutions in terms of acute biomedical injuries. The theory solutions demonstrate the complexity of possible outcomes following an idealized acute injury and indicate that a "one size fits all" therapy is unlikely to be successful. This conclusion is offset by the fact that the theory can (1) determine if a cell has the possibility to survive given a specific acute injury, and (2) calculate the degree of therapy needed to cause survival. To appreciate these conclusions, it is necessary to idealize and abstract complex physical systems to identify the fundamental mechanism governing the injury dynamics. The path of abstraction and idealization in biomedical research opens the possibility for medical treatments that may achieve engineering levels of precision.

Abstraction and Idealization in Biomedicine: The Nonautonomous Theory of Acute Cell Injury

PubMed Central

DeGracia, Donald J.; Taha, Doaa; Tri Anggraini, Fika; Sutariya, Shreya; Rababeh, Gabriel; Huang, Zhi-Feng

2018-01-01

Neuroprotection seeks to halt cell death after brain ischemia and has been shown to be possible in laboratory studies. However, neuroprotection has not been successfully translated into clinical practice, despite voluminous research and controlled clinical trials. We suggested these failures may be due, at least in part, to the lack of a general theory of cell injury to guide research into specific injuries. The nonlinear dynamical theory of acute cell injury was introduced to ameliorate this situation. Here we present a revised nonautonomous nonlinear theory of acute cell injury and show how to interpret its solutions in terms of acute biomedical injuries. The theory solutions demonstrate the complexity of possible outcomes following an idealized acute injury and indicate that a “one size fits all” therapy is unlikely to be successful. This conclusion is offset by the fact that the theory can (1) determine if a cell has the possibility to survive given a specific acute injury, and (2) calculate the degree of therapy needed to cause survival. To appreciate these conclusions, it is necessary to idealize and abstract complex physical systems to identify the fundamental mechanism governing the injury dynamics. The path of abstraction and idealization in biomedical research opens the possibility for medical treatments that may achieve engineering levels of precision. PMID:29495539

Finite element and analytical solutions for van der Pauw and four-point probe correction factors when multiple non-ideal measurement conditions coexist

NASA Astrophysics Data System (ADS)

Reveil, Mardochee; Sorg, Victoria C.; Cheng, Emily R.; Ezzyat, Taha; Clancy, Paulette; Thompson, Michael O.

2017-09-01

This paper presents an extensive collection of calculated correction factors that account for the combined effects of a wide range of non-ideal conditions often encountered in realistic four-point probe and van der Pauw experiments. In this context, "non-ideal conditions" refer to conditions that deviate from the assumptions on sample and probe characteristics made in the development of these two techniques. We examine the combined effects of contact size and sample thickness on van der Pauw measurements. In the four-point probe configuration, we examine the combined effects of varying the sample's lateral dimensions, probe placement, and sample thickness. We derive an analytical expression to calculate correction factors that account, simultaneously, for finite sample size and asymmetric probe placement in four-point probe experiments. We provide experimental validation of the analytical solution via four-point probe measurements on a thin film rectangular sample with arbitrary probe placement. The finite sample size effect is very significant in four-point probe measurements (especially for a narrow sample) and asymmetric probe placement only worsens such effects. The contribution of conduction in multilayer samples is also studied and found to be substantial; hence, we provide a map of the necessary correction factors. This library of correction factors will enable the design of resistivity measurements with improved accuracy and reproducibility over a wide range of experimental conditions.

Finite element and analytical solutions for van der Pauw and four-point probe correction factors when multiple non-ideal measurement conditions coexist.

PubMed

Reveil, Mardochee; Sorg, Victoria C; Cheng, Emily R; Ezzyat, Taha; Clancy, Paulette; Thompson, Michael O

2017-09-01

This paper presents an extensive collection of calculated correction factors that account for the combined effects of a wide range of non-ideal conditions often encountered in realistic four-point probe and van der Pauw experiments. In this context, "non-ideal conditions" refer to conditions that deviate from the assumptions on sample and probe characteristics made in the development of these two techniques. We examine the combined effects of contact size and sample thickness on van der Pauw measurements. In the four-point probe configuration, we examine the combined effects of varying the sample's lateral dimensions, probe placement, and sample thickness. We derive an analytical expression to calculate correction factors that account, simultaneously, for finite sample size and asymmetric probe placement in four-point probe experiments. We provide experimental validation of the analytical solution via four-point probe measurements on a thin film rectangular sample with arbitrary probe placement. The finite sample size effect is very significant in four-point probe measurements (especially for a narrow sample) and asymmetric probe placement only worsens such effects. The contribution of conduction in multilayer samples is also studied and found to be substantial; hence, we provide a map of the necessary correction factors. This library of correction factors will enable the design of resistivity measurements with improved accuracy and reproducibility over a wide range of experimental conditions.

Association of Ideal Cardiovascular Health and Long-term Healthcare Costs.

PubMed

Willis, Benjamin L; DeFina, Laura F; Bachmann, Justin M; Franzini, Luisa; Shay, Christina M; Gao, Ang; Leonard, David; Berry, Jarett D

2015-11-01

The American Heart Association's (AHA's) 2020 Strategic Impact Goals introduced the concept of ideal cardiovascular (CV) health based on seven health factors and behaviors associated with lower CV disease (CVD) risk. The association between CV health and healthcare costs has not been reported; therefore, we evaluated the association between CV health profile and later-life healthcare costs. Cooper Center Longitudinal Study participants (N=4,906; mean age, 56 years) receiving Medicare coverage from 1999 to 2009 were included. CV health behaviors (diet, physical activity, BMI, smoking) and CV health factors (blood pressure, total cholesterol, blood glucose) were categorized as unfavorable (zero to two ideal components); intermediate (two to four); and favorable (five to seven). Healthcare costs were cumulated from Medicare claims data, adjusted for inflation. Associations between midlife CV health status and non-CVD and CVD-related costs were estimated using multivariable quantile regression. Analyses were conducted in 2013 and 2014. Favorable CV health was prevalent in 14.8% of men and 30.1% of women, with <1% having ideal levels of all health metrics. After 31,945 person-years of Medicare follow-up, individuals with favorable CV health exhibited 24.9% (95% CI=11.7%, 36.0%) lower median annual non-CVD costs and 74.5% (57.5%, 84.7%) lower median CVD costs than those with unfavorable CV health. Annualized differences were greater for non-CVD costs than for CVD costs ($1,175 vs $566). Having more ideal CV health components in middle age, as outlined by the AHA 2020 Goals, is associated with lower non-CVD and CVD healthcare costs in later life. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

The Place of Ideals in Teaching.

ERIC Educational Resources Information Center

Hansen, David T.

This paper examines whether ideals and idealism have a role to play in teaching, identifying some ambiguities and problems associated with ideals and arguing that ideals figure importantly in teaching, but they are ideals of character or personhood as much as they are ideals of educational purpose. The first section focuses on the promise and…

Growth behavior of anodic porous alumina formed in malic acid solution

NASA Astrophysics Data System (ADS)

Kikuchi, Tatsuya; Yamamoto, Tsuyoshi; Suzuki, Ryosuke O.

2013-11-01

The growth behavior of anodic porous alumina formed on aluminum by anodizing in malic acid solutions was investigated. High-purity aluminum plates were electropolished in CH3COOH/HClO4 solutions and then anodized in 0.5 M malic acid solutions at 293 K and constant cell voltages of 200-350 V. The anodic porous alumina grew on the aluminum substrate at voltages of 200-250 V, and a black, burned oxide film was formed at higher voltages. The nanopores of the anodic oxide were only formed at grain boundaries of the aluminum substrate during the initial stage of anodizing, and then the growth region extended to the entire aluminum surface as the anodizing time increased. The anodic porous alumina with several defects was formed by anodizing in malic acid solution at 250 V, and oxide cells were approximately 300-800 nm in diameter.

Individual deals within teams: Investigating the role of relative i-deals for employee performance.

PubMed

Vidyarthi, Prajya R; Singh, Satvir; Erdogan, Berrin; Chaudhry, Anjali; Posthuma, Richard; Anand, Smriti

2016-11-01

The authors extend i-deals theory to an individual-within-a-team context. Drawing upon social comparison theory, they contend that individuals will react to their own i-deals within the context of group members' i-deals. Therefore, they examine the role of relative i-deals (an individual's i-deals relative to the team's average) in relation to employee performance. Furthermore, integrating social comparison theory with social identity theory the authors assert that the behavioral outcomes of relative i-deals are influenced by the team's social and structural attributes of team orientation and task interdependence. Finally, they contend that the perceptions of one's relative standing with the leader, or leader-member exchange social comparison (LMXSC), mediate the i-deals-outcome relationship in groups with low team orientation and task interdependence. Results of multilevel modeling using time-lagged data from 321 employees nested in 46 teams demonstrated that the positive relationship between relative i-deals and employee performance was stronger in groups with low team orientation and task interdependence, and the mediation effect of LMXSC was stronger in teams with low rather than high team orientation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Role of Idealization in Science and Its Implications for Science Education

NASA Astrophysics Data System (ADS)

Niaz, Mansoor

1999-06-01

The main objective of this article is to study the role of empirical evidence in the interpretation of psychological and epistemological aspects of Piagetian theory. According to Galilean methodology, after having asked the right question, a scientist could experimentally vary one impediment, and observe what happens to the dependent variable, as it approaches the ideal limiting case. Following Galileo's idealization, scientific laws being epistemological constructions do not describe the behavior of actual bodies. It is plausible to suggest that just as Galileo's ideal law can be observed only when all the impediment variables approach zero, similarly individuals in the real world have various `impediments' and it is only when these impediments are gradually removed by experimental manipulation that the real performance of individuals can approximate the competence of Piaget's epistemic subject (ideal knower). Finally, evidence is presented to the effect that by experimentally manipulating the impediment variables (e.g., Pascual-Leone's M-demand and Witkin's perceptual field effect of a task), performance of the real subjects approximates the competence of the ideal epistemic subject, which leads to the construction of a neo-Piagetian epistemological theory.

Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach.

PubMed

Sarkar, Abhijit; Sinha, Biswajit

2016-11-15

The densities and viscosities of lactose monohydrate in aqueous ascorbic acid solutions with several molal concentrations m=(0.00-0.08)molkg(-1) of ascorbic acid were determined at T=(298.15-318.15)K and pressure p=101kPa. Using experimental data apparent molar volume (ϕV), standard partial molar volume (ϕV(0)), the slope (SV(∗)), apparent specific volumes (ϕVsp), standard isobaric partial molar expansibility (ϕE(0)) and its temperature dependence [Formula: see text] the viscosity B-coefficient and solvation number (Sn) were determined. Viscosity B-coefficients were further employed to obtain the free energies of activation of viscous flow per mole of the solvents (Δμ1(0≠)) and of the solute (Δμ2(0≠)). Effects of molality, solute structure and temperature and taste behavior were analyzed in terms of solute-solute and solute-solvent interactions; results revealed that the solutions are characterized predominantly by solute-solvent interactions and lactose monohydrate behaves as a long-range structure maker. Copyright © 2016 Elsevier Ltd. All rights reserved.

Relativistic quantum thermodynamics of ideal gases in two dimensions.

PubMed

Blas, H; Pimentel, B M; Tomazelli, J L

1999-11-01

In this work we study the behavior of relativistic ideal Bose and Fermi gases in two space dimensions. Making use of polylogarithm functions we derive a closed and unified expression for their densities. It is shown that both type of gases are essentially inequivalent, and only in the non-relativistic limit the spinless and equal mass Bose and Fermi gases are equivalent as known in the literature.

Size effects of pore density and solute size on water osmosis through nanoporous membrane.

PubMed

Zhao, Kuiwen; Wu, Huiying

2012-11-15

Understanding the behavior of osmotic transport across nanoporous membranes at molecular level is critical to their design and applications, and it is also beneficial to the comprehension of the mechanism of biological transmembrane transport processes. Pore density is an important parameter for nanoporous membranes. To better understand the influence of pore density on osmotic transport, we have performed systematic molecular dynamics simulations on water osmosis across nanoporous membranes with different pore densities (i.e., number of pores per unit area of membrane). The simulation results reveal that significant size effects occur when the pore density is so high that the center-to-center distance between neighboring nanopores is comparable to the solute size. The size effects are independent of the pore diameter and solute concentration. A simple quantitative correlation between pore density, solute size, and osmotic flux has been established. The results are excellently consistent with the theoretical predictions. It is also shown that solute hydration plays an important role in real osmotic processes. Solute hydration strengthens the size effects of pore density on osmotic processes due to the enlarged effective solute size induced by hydration. The influence of pore density, solute size, and solute hydration on water osmosis through nanoporous membranes can be introduced to eliminate the deviations of real osmotic processes from ideal behavior.

Thinspiration: Self-Improvement Versus Self-Evaluation Social Comparisons with Thin-Ideal Media Portrayals.

PubMed

Knobloch-Westerwick, Silvia

2015-01-01

Much research has demonstrated negative impacts of idealized-body imagery exposure on body satisfaction. Yet, paradoxically, media with such imagery attract mass audiences. Few studies showed women's body satisfaction increased due to thin-ideal exposure. The kind of social comparison women engage in (self-evaluation vs. self-improvement) may explain these inconsistent findings and the paradoxical attraction to thin-ideal messages. Across 5 days, thin-ideal messages were presented to 51 women; self-evaluation and self-improvement social comparisons as well as body satisfaction were measured each day. A linear positive change in body satisfaction emerged. Greater self-improvement social comparisons increased this change, whereas greater self-evaluation social comparisons reduced it. Extent of both social comparison types changed during the prolonged exposure. A greater tendency to compare one's body with others' improved body satisfaction through self-improvement social comparisons and fostered weight-loss behaviors through self-evaluation social comparisons.

Racial Differences in Ideal Cardiovascular Health Metrics Among Mississippi Adults, 2009 Mississippi Behavioral Risk Factor Surveillance System

PubMed Central

Gamble, Abigail; Mendy, Vincent

2013-01-01

Introduction Cardiovascular disease is a leading cause of death and health disparities in Mississippi. Identifying populations with poor cardiovascular health may help direct interventions toward those populations disproportionately affected, which may ultimately increase cardiovascular health and decrease prominent disparities. Our objective was to assess racial differences in the prevalence of cardiovascular health metrics among Mississippi adults. Methods We used data from the 2009 Mississippi Behavioral Risk Factor Surveillance System to determine age-standardized prevalence estimates and 95% confidence intervals of cardiovascular health metrics among 2,003 black and 5,125 white adults. Logistic regression models were used to evaluate the relationship between race and cardiovascular health metrics. The mean cardiovascular metrics score and percentage of the population with ideal and poor cardiovascular health were calculated by subgroup. Results Approximately 1.3% of blacks and 2.6% of whites exhibited ideal levels of all 7 cardiovascular health metrics. The prevalence of 4 of the 7 cardiovascular health metrics was significantly lower among the total population of blacks than among whites, including a normal body mass index (20.8% vs 32.3%, P < .001), no history of diabetes (85.1% vs 91.3%, P < .001), no history of hypertension (53.9% vs 67.9%, P < .001), and physical activity (52.8% vs 62.2%, P < .001). The logistic regression models revealed significant race-by-sex interactions; differences between blacks and whites for normal body mass index, no history of diabetes mellitus, and no current smoking were found among women but not among men. Conclusion Cardiovascular health is poor among Mississippi adults overall, and racial differences exist. PMID:24262026

Study on tribological and electrochemistry properties of metal materials in H2O2 solutions

NASA Astrophysics Data System (ADS)

Yuan, Chengqing; Yu, Li; Li, Jian; Yan, Xinping

2012-03-01

Hydrogen peroxide (H2O2) is a kind of ideal green propellant. It is crucial to study the wear behavior and failure modes of the metal materials under the strong oxidizing environment of H2O2. This study aims to investigate the wear of rubbing pairs of 2Cr13 stainless steel against 1045 metal in H2O2 solutions, which has a great effect on wear, the decomposition and damage mechanism of materials. The comparison analysis of the friction coefficients, wear mass loss, worn surface topographies and current densities was conducted under different concentrations of H2O2 solutions. There were significant differences in the tribological and electrochemistry properties of the rubbing pairs in different H2O2 solutions.

An ideal observer analysis of visual working memory.

PubMed

Sims, Chris R; Jacobs, Robert A; Knill, David C

2012-10-01

Limits in visual working memory (VWM) strongly constrain human performance across many tasks. However, the nature of these limits is not well understood. In this article we develop an ideal observer analysis of human VWM by deriving the expected behavior of an optimally performing but limited-capacity memory system. This analysis is framed around rate-distortion theory, a branch of information theory that provides optimal bounds on the accuracy of information transmission subject to a fixed information capacity. The result of the ideal observer analysis is a theoretical framework that provides a task-independent and quantitative definition of visual memory capacity and yields novel predictions regarding human performance. These predictions are subsequently evaluated and confirmed in 2 empirical studies. Further, the framework is general enough to allow the specification and testing of alternative models of visual memory (e.g., how capacity is distributed across multiple items). We demonstrate that a simple model developed on the basis of the ideal observer analysis-one that allows variability in the number of stored memory representations but does not assume the presence of a fixed item limit-provides an excellent account of the empirical data and further offers a principled reinterpretation of existing models of VWM. PsycINFO Database Record (c) 2012 APA, all rights reserved.

An Ideal Observer Analysis of Visual Working Memory

PubMed Central

Sims, Chris R.; Jacobs, Robert A.; Knill, David C.

2013-01-01

Limits in visual working memory (VWM) strongly constrain human performance across many tasks. However, the nature of these limits is not well understood. In this paper we develop an ideal observer analysis of human visual working memory, by deriving the expected behavior of an optimally performing, but limited-capacity memory system. This analysis is framed around rate–distortion theory, a branch of information theory that provides optimal bounds on the accuracy of information transmission subject to a fixed information capacity. The result of the ideal observer analysis is a theoretical framework that provides a task-independent and quantitative definition of visual memory capacity and yields novel predictions regarding human performance. These predictions are subsequently evaluated and confirmed in two empirical studies. Further, the framework is general enough to allow the specification and testing of alternative models of visual memory (for example, how capacity is distributed across multiple items). We demonstrate that a simple model developed on the basis of the ideal observer analysis—one which allows variability in the number of stored memory representations, but does not assume the presence of a fixed item limit—provides an excellent account of the empirical data, and further offers a principled re-interpretation of existing models of visual working memory. PMID:22946744

Developmental Idealism in China

PubMed Central

Thornton, Arland; Xie, Yu

2016-01-01

This paper examines the intersection of developmental idealism with China. It discusses how developmental idealism has been widely disseminated within China and has had enormous effects on public policy and programs, on social institutions, and on the lives of individuals and their families. This dissemination of developmental idealism to China began in the 19th century, when China met with several military defeats that led many in the country to question the place of China in the world. By the beginning of the 20th century, substantial numbers of Chinese had reacted to the country’s defeats by exploring developmental idealism as a route to independence, international respect, and prosperity. Then, with important but brief aberrations, the country began to implement many of the elements of developmental idealism, a movement that became especially important following the assumption of power by the Communist Party of China in 1949. This movement has played a substantial role in politics, in the economy, and in family life. The beliefs and values of developmental idealism have also been directly disseminated to the grassroots in China, where substantial majorities of Chinese citizens have assimilated them. These ideas are both known and endorsed by very large numbers in China today. PMID:28316833

Developmental Idealism in China.

PubMed

Thornton, Arland; Xie, Yu

2016-10-01

This paper examines the intersection of developmental idealism with China. It discusses how developmental idealism has been widely disseminated within China and has had enormous effects on public policy and programs, on social institutions, and on the lives of individuals and their families. This dissemination of developmental idealism to China began in the 19 th century, when China met with several military defeats that led many in the country to question the place of China in the world. By the beginning of the 20 th century, substantial numbers of Chinese had reacted to the country's defeats by exploring developmental idealism as a route to independence, international respect, and prosperity. Then, with important but brief aberrations, the country began to implement many of the elements of developmental idealism, a movement that became especially important following the assumption of power by the Communist Party of China in 1949. This movement has played a substantial role in politics, in the economy, and in family life. The beliefs and values of developmental idealism have also been directly disseminated to the grassroots in China, where substantial majorities of Chinese citizens have assimilated them. These ideas are both known and endorsed by very large numbers in China today.

Thermodynamics of an ideal generalized gas: I. Thermodynamic laws.

PubMed

Lavenda, B H

2005-11-01

The equations of state for an ideal relativistic, or generalized, gas, like an ideal quantum gas, are expressed in terms of power laws of the temperature. In contrast to an ideal classical gas, the internal energy is a function of volume at constant temperature, implying that the ideal generalized gas will show either attractive or repulsive interactions. This is a necessary condition in order that the third law be obeyed and for matter to have an electromagnetic origin. The transition from an ideal generalized to a classical gas occurs when the two independent solutions of the subsidiary equation to Lagrange's equation coalesce. The equation of state relating the pressure to the internal energy encompasses the full range of cosmological scenarios, from the radiation to the matter dominated universes and finally to the vacuum energy, enabling the coefficient of proportionality, analogous to the Grüeisen ratio, to be interpreted in terms of the degrees of freedom related to the temperature exponents of the internal energy and the absolute temperature expressed in terms of a power of the empirical temperature. The limit where these exponents merge is shown to be the ideal classical gas limit. A corollary to Carnot's theorem is proved, asserting that the ratio of the work done over a cycle to the heat absorbed to increase the temperature at constant volume is the same for all bodies at the same volume. As power means, the energy and entropy are incomparable, and a new adiabatic potential is introduced by showing that the volume raised to a characteristic exponent is also the integrating factor for the quantity of heat so that the second law can be based on the property that power means are monotonically increasing functions of their order. The vanishing of the chemical potential in extensive systems implies that energy cannot be transported without matter and is equivalent to the condition that Clapeyron's equation be satisfied.

Spectral Analysis of Non-ideal MRI Modes: The Effect of Hall Diffusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohandas, Gopakumar; Pessah, Martin E., E-mail: gopakumar@nbi.ku.dk, E-mail: mpessah@nbi.ku.dk

The effect of magnetic field diffusion on the stability of accretion disks is a problem that has attracted considerable interest of late. In particular, the Hall effect has the potential to bring about remarkable changes in the dynamical behavior of disks that are without parallel. In this paper, we conduct a systematic examination of the linear eigenmodes in a weakly magnetized differentially rotating gas with a special focus on Hall diffusion. We first develop a geometrical representation of the eigenmodes and provide a detailed quantitative description of the polarization properties of the oscillatory modes under the combined influence of themore » Coriolis and Hall effects. We also analyze the effects of magnetic diffusion on the structure of the unstable modes and derive analytical expressions for the kinetic and magnetic stresses and energy densities associated with the non-ideal magnetorotational instability (MRI). Our analysis explicitly demonstrates that, if the dissipative effects are relatively weak, the kinetic stresses and energies make up the dominant contribution to the total stress and energy density when the equilibrium angular momentum and magnetic field vectors are anti-parallel. This is in sharp contrast to what is observed in the case of the ideal or dissipative MRI. We conduct shearing box simulations and find very good agreement with the results derived from linear theory. Because the modes under consideration are also exact solutions of the nonlinear equations, the unconventional nature of the kinetic and magnetic stresses may have significant implications for the nonlinear evolution in some regions of protoplanetary disks.« less

Ideal form of optical plasma lenses

NASA Astrophysics Data System (ADS)

Gordon, D. F.; Stamm, A. B.; Hafizi, B.; Johnson, L. A.; Kaganovich, D.; Hubbard, R. F.; Richardson, A. S.; Zhigunov, D.

2018-06-01

The canonical form of an optical plasma lens is a parabolic density channel. This form suffers from spherical aberrations, among others. Spherical aberration is partially corrected by adding a quartic term to the radial density profile. Ideal forms which lead to perfect focusing or imaging are obtained. The fields at the focus of a strong lens are computed with high accuracy and efficiency using a combination of eikonal and full Maxwell descriptions of the radiation propagation. The calculations are performed using a new computer propagation code, SeaRay, which is designed to transition between various solution methods as the beam propagates through different spatial regions. The calculations produce the full Maxwell vector fields in the focal region.

Measuring Love: Sexual Minority Male Youths’ Ideal Romantic Characteristics

PubMed Central

Bauermeister, José A.; Johns, Michelle M.; Pingel, Emily; Eisenberg, Anna; Santana, Matt Leslie; Zimmerman, Marc

2011-01-01

Research examining how sexual minorities characterize love within same-sex relationships is scarce. In this study, we examined the validity of Sternberg's Triangular Theory of Love in a sample of sexual minority male youth (N = 447). To test the adequacy of the theory for our population, we examined the psychometric properties of the Triadic Love Scale (TLS) and tested whether the three underlying constructs of the theory (Intimacy, Passion, and Commitment) emerged when participants were asked to consider their ideal relationship with another man. Using confirmatory factor analysis (CFA), we found support for the three-factor solution to characterize sexual minority male youths’ ideal romantic relationship, after minimizing item cross-loadings and adapting the content of the Passion subscale. We discuss the implications of our findings regarding the measurement of the TLS among sexual minority male youth and propose ways to enhance its measurement in future research. PMID:21709758

Predicting the Fluid-Phase Behavior of Aqueous Solutions of ELP (VPGVG) Sequences Using SAFT-VR.

PubMed

Zhao, Binwu; Lindeboom, Tom; Benner, Steven; Jackson, George; Galindo, Amparo; Hall, Carol K

2017-10-24

The statistical associating fluid theory for potentials of variable range (SAFT-VR) is used to predict the fluid phase behavior of elastin-like polypeptide (ELP) sequences in aqueous solution with special focus on the loci of lower critical solution temperatures (LCSTs). A SAFT-VR model for these solutions is developed following a coarse-graining approach combining information from atomistic simulations and from previous SAFT models for previously reported relevant systems. Constant-pressure temperature-composition phase diagrams are determined for solutions of (VPGVG) n sequences + water with n = 1 to 300. The SAFT-VR equation of state lends itself to the straightforward calculation of phase boundaries so that complete fluid-phase equilibria can be calculated efficiently. A broad range of thermodynamic conditions of temperature and pressure are considered, and regions of vapor-liquid and liquid-liquid coexistence, including LCSTs, are found. The calculated phase boundaries at low concentrations match those measured experimentally. The temperature-composition phase diagrams of the aqueous ELP solutions at low pressure (0.1 MPa) are similar to those of types V and VI phase behavior in the classification of Scott and van Konynenburg. An analysis of the high-pressure phase behavior confirms, however, that a closed-loop liquid-liquid immiscibility region, separate from the gas-liquid envelope, is present for aqueous solutions of (VPGVG) 30 ; such a phase diagram is typical of type VI phase behavior. ELPs with shorter lengths exhibit both liquid-liquid and gas-liquid regions, both of which become less extensive as the chain length of the ELP is decreased. The strength of the hydrogen-bonding interaction is also found to affect the phase diagram of the (VPGVG) 30 system in that the liquid-liquid and gas-liquid regions expand as the hydrogen-bonding strength is decreased and shrink as it is increased. The LCSTs of the mixtures are seen to decrease as the ELP chain length

Behavior of supercooled aqueous solutions stemming from hidden liquid-liquid transition in water.

PubMed

Biddle, John W; Holten, Vincent; Anisimov, Mikhail A

2014-08-21

A popular hypothesis that explains the anomalies of supercooled water is the existence of a metastable liquid-liquid transition hidden below the line of homogeneous nucleation. If this transition exists and if it is terminated by a critical point, the addition of a solute should generate a line of liquid-liquid critical points emanating from the critical point of pure metastable water. We have analyzed thermodynamic consequences of this scenario. In particular, we consider the behavior of two systems, H2O-NaCl and H2O-glycerol. We find the behavior of the heat capacity in supercooled aqueous solutions of NaCl, as reported by Archer and Carter [J. Phys. Chem. B 104, 8563 (2000)], to be consistent with the presence of the metastable liquid-liquid transition. We elucidate the non-conserved nature of the order parameter (extent of "reaction" between two alternative structures of water) and the consequences of its coupling with conserved properties (density and concentration). We also show how the shape of the critical line in a solution controls the difference in concentration of the coexisting liquid phases.

Associations between Sexual Abstinence Ideals, Religiosity, and Alcohol Abstinence: A Longitudinal Study of Finnish Twins

PubMed Central

Winter, Torsten; Karvonen, Sakari; Rose, Richard J.

2016-01-01

We analyzed prevalence and stability of attitudes endorsing sexual abstinence ideals from late adolescence into early adulthood and studied associations of these attitudes with religiosity and alcohol abstinence in a sexually liberal Nordic society. Our population-based sample of Finnish twins permitted comparisons of co-twins concordant for religiosity but discordant for drinking to evaluate the association of sexual abstinence ideals with alcohol abstinence, controlling for household environment. From age 17 to 24, endorsement of sexual abstinence as a romantic ideal declined from 25% to 15%. Religiosity and alcohol abstinence correlated, both separately and together, with endorsing sexual abstinence. Abstinence ideals were associated with literal belief in fundamental tenets of the Bible. The association of sexual abstinence ideals with alcohol abstinence was confirmed in within-family comparisons of co-twins discordant for drinking but concordant for religiosity. Alcohol-abstinent twins were significantly more likely than their non-alcohol-abstinent twin siblings to endorse sexual abstinence ideals; that result suggests the association of sexual abstinence ideals with abstaining from alcohol is not explained by unmeasured confounds in familial background and structure. Our longitudinal results and analyses of discordant twins suggest that attitudes toward sexual abstinence ideals are embedded within other conservative attitudes and behaviors. PMID:23301620

Prevalence of Ideal Cardiovascular Health and Its Association with Cognitive Function in Older Adults: The Chilean National Health Survey (2009-2010).

PubMed

García-Hermoso, Antonio; Ramírez-Vélez, Robinson; Ramírez-Campillo, Rodrigo; Izquierdo, Mikel

2017-10-23

Health behaviors and risk factors are independently related with cognitive function in older adults. This study aimed at examining the prevalence and relationship between cognitive function and a number of ideal cardiovascular health (CVH) metrics in older adults from the 2009 to 2010 Chilean National Health Survey. Data from 460 older adults (mean age 73.5 years old, 59.3% women) from the 2009 to 2010 Chilean Health Survey were analyzed. Ideal CVH was defined as meeting the ideal levels of the following components: four behaviors (smoking, body mass index, physical activity, and diet adherence) and three factors (total cholesterol, blood pressure, and fasting glucose). Older adults were grouped into three categories according to their number of ideal CVH metrics: ideal (5-7 metrics), intermediate (3-4 metrics), and poor (0-2 metrics). Cognitive function was assessed by using the modified Mini-Mental Status Examination (mMMSE). Of the 460 participants, 2% had 0 ideal metrics, 11.3% had 1, 23.9% had 2, 32.2% had 3, 20.7% had 4, 9.6% had 5, 0.4% had 6, and 0% had 7. Cognitive function was greater in older adults who met the ideal smoking, physical activity, and fasting blood glucose criteria. Logistic regression analysis suggested that ideal physical activity (Odds Ratio [OR] = 0.411 95% confidence interval [95% CI], 0.209-0.807) and smoking (OR = 0.429 95% CI, 0.095-0.941) behaviors reduced the likelihood of cognitive impairment. Moreover, compared with a poor profile (0-2 metrics), an intermediate (3-4 metrics) (OR = 0.221 95% CI, 0.024-0.911) and ideal CVH profile (5-7 metrics) (OR = 0.106 95% CI, 0.013-0.864) reduced the likelihood of cognitive impairment. We found that intermediate and ideal profiles were associated with a similarly low prevalence of cognitive impairment in Chilean older adults.

The influence of traffic signal solutions on self-reported road-crossing behavior.

PubMed

Di Stasi, Leandro L; Megías, Alberto; Cándido, Antonio; Maldonado, Antonio; Catena, Andrés

2015-01-07

Injury to pedestrians is a major safety hazard in many countries. Since the beginning of the last century, modern cities have been designed around the use of motor vehicles despite the unfavourable interactions between the vehicles and pedestrians. This push towards urbanization resulted in a substantial number of crashes and fatalities involving pedestrians every day, all over the world. Thus, improving the design of urban cities and townships is a pressing issue for modern society. The study presented here provides a characterization of pedestrian safety problems, with the emphasis on signalized crosswalks (i.e. traffic signal) design solutions. We tested the impact of seven different traffic light configurations (steady [green, yellow, and red], flashing [green, yellow, and red], and light off) on pedestrian self-reported road-crossing behavior, using a 11-point scale -ranging from 0 ("I never cross in this situation") to 10 ("I always cross in this situation"). Results showed that mandatory solutions (steady green vs. steady red) are the best solutions to avoid unsafe pedestrian behaviors while crossing controlled intersections (frequency of crossing: Mgreen = 9.4 ± 1 vs. Mred = 2.6 ± 2). These findings offer important guidelines for the design of future traffic signals for encouraging a pedestrian/transit-friendly environment.

Developmental and behavioral consequences of prenatal methamphetamine exposure: a review of the Infant Development, Environment, and Lifestyle (IDEAL) Study

PubMed Central

Smith, Lynne M.; Diaz, Sabrina; LaGasse, Linda L.; Wouldes, Trecia; Derauf, Chris; Newman, Elana; Arria, Amelia; Huestis, Marilyn A.; Haning, William; Strauss, Arthur; Grotta, Sheri Della; Dansereau, Lynne M.; Neal, Charles; Lester, Barry M.

2015-01-01

This study reviews the findings from the Infant Development, Environment, and Lifestyle Study (IDEAL), a multisite, longitudinal, prospective study designed to determine maternal outcome and child growth and developmental findings following prenatal methamphetamine exposure from birth up to age 7.5 years. These findings are presented in the context of the home environment and caregiver characteristics to determine how the drug and the environment interact to affect the outcome of these children. No neonatal abstinence syndrome requiring pharmacologic intervention was observed but heavy drug exposure was associated with increased stress responses in the neonatal period. Poorer inhibitory control was also observed in heavy methamphetamine exposed children placing them at high risk for impaired executive function. Independent of methamphetamine exposure, children with more responsive home environments to developmental and emotional needs demonstrated lower risks for internalizing and externalizing behavior. PMID:26212684

Computational-hydrodynamic studies of the Noh compressible flow problem using non-ideal equations of state

NASA Astrophysics Data System (ADS)

Honnell, Kevin; Burnett, Sarah; Yorke, Chloe'; Howard, April; Ramsey, Scott

2017-06-01

The Noh problem is classic verification problem in the field of compressible flows. Simple to conceptualize, it is nonetheless difficult for numerical codes to predict correctly, making it an ideal code-verification test bed. In its original incarnation, the fluid is a simple ideal gas; once validated, however, these codes are often used to study highly non-ideal fluids and solids. In this work the classic Noh problem is extended beyond the commonly-studied polytropic ideal gas to more realistic equations of state (EOS) including the stiff gas, the Nobel-Abel gas, and the Carnahan-Starling hard-sphere fluid, thus enabling verification studies to be performed on more physically-realistic fluids. Exact solutions are compared with numerical results obtained from the Lagrangian hydrocode FLAG, developed at Los Alamos. For these more realistic EOSs, the simulation errors decreased in magnitude both at the origin and at the shock, but also spread more broadly about these points compared to the ideal EOS. The overall spatial convergence rate remained first order.

Thermal expansion behavior of fluor-chlorapatite crystalline solutions

NASA Astrophysics Data System (ADS)

Hovis, G.; Harlov, D.; Gottschalk, M.; Hudacek, W.; Wildermuth, S.

2009-04-01

Apatite Ca5(PO4)3(F,Cl,OH,CO3) occurs widely as an accessory mineral in many igneous and metamorphic rocks and in nature displays a wide range of F-Cl-OH-CO3 mixtures (e.g., O'Reilly and Griffin, 2000) that have been used to interpret the role of fluids, e.g. Cl, F, and OH activities, during metamorphic and igneous processes (e.g., Harlov and Förster, 2002). It is important, therefore, to understand the thermodynamic behavior of these solid solutions, including their thermal expansion properties. Fluorapatite - chlorapatite samples were synthesized at the GFZ-Potsdam (Hovis, Harlov, Hahn and Steigert, 2007) using an adaptation of the molten flux method of Cherniak (2000). Dry CaF2 and CaCl2 (0.1 mole total) were mixed with Ca3(PO4)2 (0.03 moles), placed in a Pt crucible, equilibrated for 15 hours at 1375 °C, cooled to 1220 °C at 3 °C/hour, removed from the oven and cooled in air. Crystals were separated from the flux by boiling the quenched product in water. F:Cl fractions for each sample were determined via Rietveld refinement of X-ray powder diffraction data. Chemical homogeneity was confirmed by Rietveld refinement and high-contrast back-scattered electron imaging. Room-temperature unit-cell volumes were determined at the GFZ-Potsdam through Rietveld analysis of X-ray powder diffraction data and also at Lafayette College by standard unit-cell refinement techniques (Holland and Redfern, 1997) using NBS/NIST 640a Si as an internal standard. High-temperature unit-cell dimensions were calculated from X-ray powder diffraction data collected at Cambridge University from room temperature to 1000 °C on a Bruker D8 X-ray diffractometer. NBS Si again was utilized as an internal standard; high-temperature Si peak positions were taken from Parrish (1953). Results indicate that despite the considerable size difference between fluorine and chlorine ions, reflected by substantially different unit-cell sizes at room temperature, the coefficient of thermal expansion across

Bin packing problem solution through a deterministic weighted finite automaton

NASA Astrophysics Data System (ADS)

Zavala-Díaz, J. C.; Pérez-Ortega, J.; Martínez-Rebollar, A.; Almanza-Ortega, N. N.; Hidalgo-Reyes, M.

2016-06-01

In this article the solution of Bin Packing problem of one dimension through a weighted finite automaton is presented. Construction of the automaton and its application to solve three different instances, one synthetic data and two benchmarks are presented: N1C1W1_A.BPP belonging to data set Set_1; and BPP13.BPP belonging to hard28. The optimal solution of synthetic data is obtained. In the first benchmark the solution obtained is one more container than the ideal number of containers and in the second benchmark the solution is two more containers than the ideal solution (approximately 2.5%). The runtime in all three cases was less than one second.

Electrolyte Solutions and Specific Ion Effects on Interfaces

ERIC Educational Resources Information Center

Friedman, Ran

2013-01-01

Introductory general and physical chemistry courses often deal with colligative properties of solutions and do not discuss nonideal solutions in detail. Yet, a growing body of evidence reveals that even at physiological concentrations electrolyte solutions cannot be treated as ideal when a charged or partially charged solute (such as a protein) is…

Electromagnetism; Problems and solutions

NASA Astrophysics Data System (ADS)

Ilie, Carolina C.; Schrecengost, Zachariah S.

2016-11-01

Electromagnetism: Problems and solutions is an ideal companion book for the undergraduate student-sophomore, junior, or senior-who may want to work on more problems and receive immediate feedback while studying. Each chapter contains brief theoretical notes followed by the problem text with the solution and ends with a brief bibliography. Also presented are problems more general in nature, which may be a bit more challenging.

Global low-energy weak solution and large-time behavior for the compressible flow of liquid crystals

NASA Astrophysics Data System (ADS)

Wu, Guochun; Tan, Zhong

2018-06-01

In this paper, we consider the weak solution of the simplified Ericksen-Leslie system modeling compressible nematic liquid crystal flows in R3. When the initial data are of small energy and initial density is positive and essentially bounded, we prove the existence of a global weak solution in R3. The large-time behavior of a global weak solution is also established.

Redox condition in molten salts and solute behavior: A first-principles molecular dynamics study

NASA Astrophysics Data System (ADS)

Nam, Hyo On; Morgan, Dane

2015-10-01

Molten salts technology is of significant interest for nuclear, solar, and other energy systems. In this work, first-principles molecular dynamics (FPMD) was used to model the solute behavior in eutectic LiCl-KCl and FLiBe (Li2BeF4) melts at 773 K and 973 K, respectively. The thermo-kinetic properties for solute systems such as the redox potential, solute diffusion coefficients and structural information surrounding the solute were predicted from FPMD modeling and the calculated properties are generally in agreement with the experiments. In particular, we formulate an approach to model redox energetics vs. chlorine (or fluorine) potential from first-principles approaches. This study develops approaches for, and demonstrates the capabilities of, FPMD to model solute properties in molten salts.

Collisionless Spectral Kinetic Simulation of Ideal Multipole Resonance Probe

NASA Astrophysics Data System (ADS)

Gong, Junbo; Wilczek, Sebastian; Szeremley, Daniel; Oberrath, Jens; Eremin, Denis; Dobrygin, Wladislaw; Schilling, Christian; Friedrichs, Michael; Brinkmann, Ralf Peter

2016-09-01

Active Plasma Resonance Spectroscopy denotes a class of industry-compatible plasma diagnostic methods which utilize the natural ability of plasmas to resonate on or near the electron plasma frequency ωpe. One particular realization of APRS with a high degree of geometric and electric symmetry is the Multipole Resonance Probe (MRP). The Ideal MRP(IMRP) is an even more symmetric idealization which is suited for theoretical investigations. In this work, a spectral kinetic scheme is presented to investigate the behavior of the IMRP in the low pressure regime. However, due to the velocity difference, electrons are treated as particles whereas ions are only considered as stationary background. In the scheme, the particle pusher integrates the equations of motion for the studied particles, the Poisson solver determines the electric field at each particle position. The proposed method overcomes the limitation of the cold plasma model and covers kinetic effects like collisionless damping.

Invariant Type-B characteristics of drag-reducing microalgal biopolymer solutions

NASA Astrophysics Data System (ADS)

Gasljevic, K.; Hall, K.; Chapman, D.; Matthys, E. F.

2017-05-01

The drag-reducing properties of polysaccharides from marine microalgae were investigated. They were compared to two drag-reducing additives studied extensively in the past, synthetic poly(ethylene) oxide, one of the most effective drag-reducing additives; and Xanthan Gum, another biopolymer often considered a model polymer for chemical and rheological research. Compared to Xanthan Gum, the most effective polymers from our microalgae show a higher drag-reducing efficiency in terms of necessary concentration to achieve a given level of drag reduction. In addition, they show a striking Type-B drag reduction behavior, which may be a very useful quality in most drag reduction applications, thanks to the independence of the drag reduction level on flow conditions such as velocity, shear stress, and tube diameter. With these polymers from microalgae we did not see evidence of Type-A behavior over the wide range of conditions studied (including pipe diameters up to 52 mm). Importantly, this suggests that the Drag Reduction coefficient in pipe flow for ideal drag-reducing solutions such as the polysaccharides investigated here is invariant at a given additive concentration of flow or solution parameters like ionic strength and can be used as a solution property to predict its drag reduction effectiveness over a wide range of conditions. On the contrary, Xanthan Gum showed evidence of both Type-A behavior in large diameter pipes and Type-B behavior in smaller ones. The polymers from microalgae also showed high resistance to degradation. Considering that these microalgae are very effective producers of polysaccharides (both extracellular and intracellular), they appear to be very promising additives for drag reduction applications.

The Role of Solvent-Solute Interactions on The Behavior of Low Molecular Mass Organo-Gelators

NASA Astrophysics Data System (ADS)

Cavicchi, Kevin; Feng, Li

2012-02-01

Low molecular mass organo-gelators (LMOGs) are a class of small molecules that can self-assemble in organic solvents to form three-dimensional fibrillar networks. This has a profound effect on the viscoelastic properties of the solution causing physical gelation. These gels have uses in a range of industries including cosmetics, foodstuffs, plastics, petroleum and pharmaceuticals. A fundamental question in this field is: What makes a good LMOG? This talk will discuss the relationships between the viscoelastic properties and thermodynamic phase behavior of LMOG/solvent solutions. The regular solution model was used to fit the liquidus line and sol/gel transition temperature vs. concentration in different solvents to determine LMOG-solvent interaction parameters (χ = A/T). This parameter A was found to scale with the solubility parameter of the solvent, especially for non-polar solvents. This demonstrates that gelation is strongly linked to LMOG solubility and indicates that the bulk thermodynamic parameters of the LMOG (solubility parameter and melting temperature) are useful to predict the solution behavior of LMOGs.

Thermodynamic nonequilibrium phase change behavior and thermal properties of biological solutions for cryobiology applications.

PubMed

Han, Bumsoo; Bischof, John C

2004-04-01

Understanding the phase change behavior of biomaterials during freezing/thawing including their thermal properties at low temperatures is essential to design and improve cryobiology applications such as cryopreservation and cryosurgery. However, knowledge of phase change behavior and thermal properties of various biomaterials is still incomplete, especially at cryogenic temperatures (< or = -40 degrees C). Moreover, in these applications, chemicals are often added to improve their outcome, which can result in significant variation in the phase change behavior and thermal properties from those of the original biomaterials. These chemical additives include cryoprotective agents (CPAs), antifreeze protein (AFP), or cryosurgical adjuvants like sodium chloride (NaCl). In the present study, phase change behavior and thermal properties of saline solutions--either water-NaCl or phosphate buffered saline (PBS)--with various chemical additives were investigated. The chemical additives studied are glycerol and raffinose as CPAs, an AFP (Type III, molecular weight = 6500), and NaCl as a cryosurgical adjuvant. The phase change behavior was investigated using a differential scanning calorimeter (DSC) and a cryomicroscope. The specific and latent heat of these solutions were also measured with the DSC. The saline solutions have two distinct phase changes--water/ice and eutectic phase changes. During freezing, eutectic solidification of both water-NaCl and PBS are significantly supercooled below their thermodynamic equilibrium eutectic temperatures. However, their melting temperatures are close to thermodynamic equilibrium during thawing. These eutectic phase changes disappear when even a small amount (0.1 M glycerol) of CPA was added, but they are still observed after the addition of an AFP. The specific heats of these solutions are close to that of ice at very low temperatures (< or = -100 degrees C) regardless of the additives, but they increase between -100 degrees C and -30

Behavior of supercooled aqueous solutions stemming from hidden liquid–liquid transition in water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biddle, John W.; Holten, Vincent; Anisimov, Mikhail A., E-mail: anisimov@umd.edu

2014-08-21

A popular hypothesis that explains the anomalies of supercooled water is the existence of a metastable liquid–liquid transition hidden below the line of homogeneous nucleation. If this transition exists and if it is terminated by a critical point, the addition of a solute should generate a line of liquid–liquid critical points emanating from the critical point of pure metastable water. We have analyzed thermodynamic consequences of this scenario. In particular, we consider the behavior of two systems, H{sub 2}O-NaCl and H{sub 2}O-glycerol. We find the behavior of the heat capacity in supercooled aqueous solutions of NaCl, as reported by Archermore » and Carter [J. Phys. Chem. B 104, 8563 (2000)], to be consistent with the presence of the metastable liquid–liquid transition. We elucidate the non-conserved nature of the order parameter (extent of “reaction” between two alternative structures of water) and the consequences of its coupling with conserved properties (density and concentration). We also show how the shape of the critical line in a solution controls the difference in concentration of the coexisting liquid phases.« less

Intra-accumbens Raclopride Administration Prevents Behavioral Changes Induced by Intermittent Access to Sucrose Solution.

PubMed

Suárez-Ortiz, Josué O; Cortés-Salazar, Felipe; Malagón-Carrillo, Ariadna L; López-Alonso, Verónica E; Mancilla-Díaz, Juan M; Tejas-Juárez, Juan G; Escartín-Pérez, Rodrigo E

2018-01-01

Overeating is one of the most relevant clinical features in Binge Eating Disorder and in some obesity patients. According to several studies, alterations in the mesolimbic dopaminergic transmission produced by non-homeostatic feeding behavior may be associated with changes in the reward system similar to those produced by drugs of abuse. Although it is known that binge-eating is related with changes in dopaminergic transmission mediated by D2 receptors in the nucleus accumbens shell (NAcS), it has not been determined whether these receptors may be a potential target for the treatment of eating pathology with binge-eating. Accordingly, the aim of the present study was to evaluate whether sugar binging induced by intermittent access to a sucrose solution produced changes in the structure of feeding behavior and whether blocking D2 receptors prevented these changes. We used the intermittent access model to a 10% sucrose solution (2 h/day for 4 weeks) to induce sugar binging in Sprague Dawley female rats. Experimental subjects consumed in a 2-h period more than 50% of the caloric intake consumed by the subjects with ad-lib access to the sweetened solution without any increase in body weight or fat accumulation. Furthermore, we evaluated whether sugar binging was associated to the estrous cycle and we did not find differences in caloric intake (estrous vs. diestrus). Subsequently, we characterized the structure of feeding behavior (microstructural analysis) and the motivation for palatable food (breakpoints) of the subjects with sugar binging and found that feeding episodes had short latencies, high frequencies, as well as short durations and inter-episode intervals. The intermittent access model did not increase breakpoints, as occurred in subjects with ad-lib access to the sucrose. Finally, we evaluated the effects of D2 receptor blockade in the NAcS, and found that raclopride (18 nM) prevented the observed changes in the frequency and duration of episodes induced by

Intra-accumbens Raclopride Administration Prevents Behavioral Changes Induced by Intermittent Access to Sucrose Solution

PubMed Central

Suárez-Ortiz, Josué O.; Cortés-Salazar, Felipe; Malagón-Carrillo, Ariadna L.; López-Alonso, Verónica E.; Mancilla-Díaz, Juan M.; Tejas-Juárez, Juan G.; Escartín-Pérez, Rodrigo E.

2018-01-01

Overeating is one of the most relevant clinical features in Binge Eating Disorder and in some obesity patients. According to several studies, alterations in the mesolimbic dopaminergic transmission produced by non-homeostatic feeding behavior may be associated with changes in the reward system similar to those produced by drugs of abuse. Although it is known that binge-eating is related with changes in dopaminergic transmission mediated by D2 receptors in the nucleus accumbens shell (NAcS), it has not been determined whether these receptors may be a potential target for the treatment of eating pathology with binge-eating. Accordingly, the aim of the present study was to evaluate whether sugar binging induced by intermittent access to a sucrose solution produced changes in the structure of feeding behavior and whether blocking D2 receptors prevented these changes. We used the intermittent access model to a 10% sucrose solution (2 h/day for 4 weeks) to induce sugar binging in Sprague Dawley female rats. Experimental subjects consumed in a 2-h period more than 50% of the caloric intake consumed by the subjects with ad-lib access to the sweetened solution without any increase in body weight or fat accumulation. Furthermore, we evaluated whether sugar binging was associated to the estrous cycle and we did not find differences in caloric intake (estrous vs. diestrus). Subsequently, we characterized the structure of feeding behavior (microstructural analysis) and the motivation for palatable food (breakpoints) of the subjects with sugar binging and found that feeding episodes had short latencies, high frequencies, as well as short durations and inter-episode intervals. The intermittent access model did not increase breakpoints, as occurred in subjects with ad-lib access to the sucrose. Finally, we evaluated the effects of D2 receptor blockade in the NAcS, and found that raclopride (18 nM) prevented the observed changes in the frequency and duration of episodes induced by

Theory and Simulation of Real and Ideal Magnetohydrodynamic Turbulence

NASA Technical Reports Server (NTRS)

Shebalin, John V.

2004-01-01

Incompressible, homogeneous magnetohydrodynamic (MHD) turbulence consists of fluctuating vorticity and magnetic fields, which are represented in terms of their Fourier coefficients. Here, a set of five Fourier spectral transform method numerical simulations of two-dimensional (2-D) MHD turbulence on a 512(sup 2) grid is described. Each simulation is a numerically realized dynamical system consisting of Fourier modes associated with wave vectors k, with integer components, such that k = |k| less than or equal to k(sub max). The simulation set consists of one ideal (non-dissipative) case and four real (dissipative) cases. All five runs had equivalent initial conditions. The dimensions of the dynamical systems associated with these cases are the numbers of independent real and imaginary parts of the Fourier modes. The ideal simulation has a dimension of 366104, while each real simulation has a dimension of 411712. The real runs vary in magnetic Prandtl number P(sub M), with P(sub M) is a member of {0.1, 0.25, 1, 4}. In the results presented here, all runs have been taken to a simulation time of t = 25. Although ideal and real Fourier spectra are quite different at high k, they are similar at low values of k. Their low k behavior indicates the existence of broken symmetry and coherent structure in real MHD turbulence, similar to what exists in ideal MHD turbulence. The value of PM strongly affects the ratio of kinetic to magnetic energy and energy dissipation (which is mostly ohmic). The relevance of these results to 3-D Navier-Stokes and MHD turbulence is discussed.

Charge Behaviors around Oxide Device/Pseudo-Physiological Solution Interface with Molecular Dynamic Simulations

NASA Astrophysics Data System (ADS)

Maekawa, Yuki; Shibuta, Yasushi; Sakata, Toshiya

2013-12-01

In this study, we investigated the charge behaviors of ions and water molecules at the oxide device/pseudo-physiological solution interface by use of molecular dynamics (MD) simulations because the detection principle of semiconductor-based biosensors is based on the detection of charge density changes at the oxide sensing surface in physiological environments. In particular, we designed an alpha-quartz (100) surface with some charges corresponding to pH=5.5 so that the ionic behaviors for 500 mM each of Na+ and Cl- around the interface were calculated under the surface condition with charges, considering a real system. As a result of the simulation, we defined the region of Debye length from the calculated potential distribution, in which some parameters such as diffusion coefficient and the vibration of water molecules around the interface differed from those of the bulk solution. The elucidation of the solid/liquid interfacial behaviors by the simulation technique should deepen our understanding of the detection principle of semiconductor-based biosensors and will give guidelines for the design of a bio-interface in the field of biosensing technology, because they cannot be demonstrated experimentally.

An Analysis of the Effect of Surface Heat Exchange on the Thermal Behavior of an Idealized Aquifer Thermal Energy Storage System

NASA Astrophysics Data System (ADS)

Güven, O.; Melville, J. G.; Molz, F. J.

1983-06-01

Analytical expressions are derived for the temperature distribution and the mean temperature of an idealized aquifer thermal energy storage (ATES) system, taking into account the heat exchange at the ground surface and the finite thickness of the overlying layer above the storage aquifer. The analytical expressions for the mean temperature may be used to obtain rough estimates of first-cycle recovery factors for preliminary evaluations of shallow confined or unconfined ATES systems. The results, which are presented in nondimensional plots, indicate that surface heat exchange may have a significant influence on the thermal behavior of shallow ATES systems. Thus it is suggested that the effects of surface heat exchange should be considered carefully and included in the detailed analyses of such ATES systems.

Terahertz absorption of lysozyme in solution

NASA Astrophysics Data System (ADS)

Martin, Daniel R.; Matyushov, Dmitry V.

2017-08-01

Absorption of radiation by solution is described by its frequency-dependent dielectric function and can be viewed as a specific application of the dielectric theory of solutions. For ideal solutions, the dielectric boundary-value problem separates the polar response into the polarization of the void in the liquid, created by the solute, and the response of the solute dipole. In the case of a protein as a solute, protein nuclear dynamics do not project on significant fluctuations of the dipole moment in the terahertz domain of frequencies and the protein dipole can be viewed as dynamically frozen. Absorption of radiation then reflects the interfacial polarization. Here we apply an analytical theory and computer simulations to absorption of radiation by an ideal solution of lysozyme. Comparison with the experiment shows that Maxwell electrostatics fails to describe the polarization of the protein-water interface and the "Lorentz void," which does not anticipate polarization of the interface by the external field (no surface charges), better represents the data. An analytical theory for the slope of the solution absorption against the volume fraction of the solute is formulated in terms of the cavity field response function. It is calculated from molecular dynamics simulations in good agreement with the experiment. The protein hydration shell emerges as a separate sub-ensemble, which, collectively, is not described by the standard electrostatics of dielectrics.

SORPTION AND DESORPTION BY IDEAL TWO-COMPARTMENT SYSTEMS: UNUSUAL BEHAVIOR AND DATA INTERPRETATION PROBLEMS

EPA Science Inventory

This paper presents an evaluation of the results of fitting curves to isotherm and kinetic data for idealized two-compartment systems of soil or sediment. Data were produced by numerically solving sets of Freundlich isotherm and first-order kinetics equations for mixtures of up ...

Chemical thermodynamics of ultrasound speed in solutions and liquid mixtures.

PubMed

Reis, João Carlos R; Santos, Angela F S; Lampreia, Isabel M S

2010-02-01

A comprehensive formalism is developed to treat thermodynamically speed of ultrasound data for solutions and liquid mixtures. For solutions, the apparent speed of ultrasound of a solute is introduced and proposed to take the place of empirically defined quantities. The partial speed of ultrasound of a solute is defined and related to the partial molar volume and partial molar isentropic compression. For liquid mixtures, the concept of speed of sound before mixing pure liquids is presented and used to define the change in speed of ultrasound upon ideal mixing, which is predicted to be generally a negative quantity. A new thermodynamic equation is derived linking the values for excess speed of ultrasound, excess molar volume and excess molar isentropic compression of a mixture, and its applications are discussed. Ideal and excess apparent speeds of ultrasound, as well as ideal and excess partial speeds of ultrasound, are defined for substances making up a liquid mixture. Accurate speeds of ultrasound in 31 mixtures of water with the amphiphile 2-(ethylamino)ethanol at 293.15 K are reported. These data are used to demonstrate the ability of the apparent speed of ultrasound to describe the impact of solutes on sonic properties of solutions and the advantages of analysing thermodynamic properties of binary liquid mixtures in terms of the dependence on composition of Balankina's ratios between excess and ideal values. It is concluded that the new thermodynamic functions defined for speeds of ultrasound in solutions and liquid mixtures give, at the least, equivalent information on molecular aspects to the usual functions related to the isentropic compressibility, without needing density data for this purpose.

Symmetry breaking in optimal timing of traffic signals on an idealized two-way street.

PubMed

Panaggio, Mark J; Ottino-Löffler, Bertand J; Hu, Peiguang; Abrams, Daniel M

2013-09-01

Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this "green-wave" scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counterintuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive density increases.

Symmetry breaking in optimal timing of traffic signals on an idealized two-way street

NASA Astrophysics Data System (ADS)

Panaggio, Mark J.; Ottino-Löffler, Bertand J.; Hu, Peiguang; Abrams, Daniel M.

2013-09-01

Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this “green-wave” scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counterintuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive density increases.

Health students' expectations of the ideal educational environment: a qualitative research.

PubMed

Aghamolaei, Teamur; Shirazi, Mandana; Dadgaran, Ideh; Shahsavari, Hooman; Ghanbarnejad, Amin

2014-10-01

Educational environment is an important determinant of students' behavior and its elements are associated with academic achievement and course satisfaction. The aim of this study was to determine students' expectations of the ideal educational environment. This was a qualitative study with content analysis approach. Using a theoretical sampling method, we selected eight students from Health School of Hormozgan University of Medical Sciences, studying health education, public health, environmental health, occupational health and medical entomology. To collect data, semi-structured interviews were used and continued until reaching data saturation. Qualitative content analysis was used to analyze the data. Students' expectations of the ideal educational environment emerged in four main themes including school atmosphere, teaching, human aspects (with three subthemes including teachers, students, and school staff) and non-human aspects (with two subthemes including educational equipment and physical environment). Educational environment is a multidimensional issue and to achieve an ideal educational environment, educational planners should meet the students' expectations of the school atmosphere, teaching, teachers, students, school staff, educational equipment and physical environment.

Health students’ expectations of the ideal educational environment: a qualitative research

PubMed Central

AGHAMOLAEI, TEAMUR; SHIRAZI, MANDANA; DADGARAN, IDEH; SHAHSAVARI, HOOMAN; GHANBARNEJAD, AMIN

2014-01-01

Introduction: Educational environment is an important determinant of students’ behavior and its elements are associated with academic achievement and course satisfaction. The aim of this study was to determine students’ expectations of the ideal educational environment. Methods: This was a qualitative study with content analysis approach. Using a theoretical sampling method, we selected eight students from Health School of Hormozgan University of Medical Sciences, studying health education, public health, environmental health, occupational health and medical entomology. To collect data, semi-structured interviews were used and continued until reaching data saturation. Qualitative content analysis was used to analyze the data. Results: Students' expectations of the ideal educational environment emerged in four main themes including school atmosphere, teaching, human aspects (with three subthemes including teachers, students, and school staff) and non-human aspects (with two subthemes including educational equipment and physical environment). Conclusion: Educational environment is a multidimensional issue and to achieve an ideal educational environment, educational planners should meet the students' expectations of the school atmosphere, teaching, teachers, students, school staff, educational equipment and physical environment. PMID:25512939

From the ideal market to the ideal clinic: constructing a normative standard of fairness for human subjects research.

PubMed

Phillips, Trisha

2011-02-01

Preventing exploitation in human subjects research requires a benchmark of fairness against which to judge the distribution of the benefits and burdens of a trial. This paper proposes the ideal market and its fair market price as a criterion of fairness. The ideal market approach is not new to discussions about exploitation, so this paper reviews Wertheimer's inchoate presentation of the ideal market as a principle of fairness, attempt of Emanuel and colleagues to apply the ideal market to human subjects research, and Ballantyne's criticisms of both the ideal market and the resulting benchmark of fairness. It argues that the criticism of this particular benchmark is on point, but the rejection of the ideal market is mistaken. After presenting a complete account of the ideal market, this paper proposes a new method for applying the ideal market to human subjects research and illustrates the proposal by considering a sample case.

Three-dimensional ideal theta(1)/theta(2) angular transformer and its uses in fiber optics.

PubMed

Ning, X

1988-10-01

A 3-D ideal theta(1)/theta(2) angular transformer in nonimaging optics is introduced. The axially symmetric transformer, combining a portion of a hyperbolic concentrator with two lenses, transforms an input limited Lambertian over an angle theta(1) to an output limited Lambertian over an angle theta(2) without losing throughput. This is the first known transformer with such ideal properties. Results of computer simulations of a transformer with planospherical lenses are presented. Because of its ideal angular transforming property, the transformer offers an excellent solution for power launching and fiber-fiber coupling in optical fiber systems. In principle, the theoretical maximum coupling efficiency based on radiance conservation can be achieved with this transformer. Several conceptual designs of source-fiber and fiber-fiber couplers using the transformer are given.

An ideal clamping analysis for a cross-ply laminate

NASA Technical Reports Server (NTRS)

Valisetty, R. R.; Murthy, P. L. N.; Rehfield, L. W.

1988-01-01

Different elementary clamping models are discussed for a three layer crossply laminate to study the sensitivity of clamping to the definition of cross-sectional rotation. All of these models leave a considerable residual warping at the edges. Using a complimentary energy principle and principle of superposition, an analysis is conducted to reduce this residual warping. This led to the identification of exact interior solution corresponding to the ideal clamping. This study also suggests a presence of stress singularities at the corners and between different layers near the fixed edge.

Ideals and Category Typicality

ERIC Educational Resources Information Center

Kim, ShinWoo; Murphy, Gregory L.

2011-01-01

Barsalou (1985) argued that exemplars that serve category goals become more typical category members. Although this claim has received support, we investigated (a) whether categories have a single ideal, as negatively valenced categories (e.g., cigarette) often have conflicting goals, and (b) whether ideal items are in fact typical, as they often…

Active Mesogenic Droplets: Impact of Liquid Crystallinity and Collective Behavior

NASA Astrophysics Data System (ADS)

Bahr, Christian

Droplets of common mesogenic compounds show a self-propelled motion when immersed in aqueous solutions containing ionic surfactants at concentrations well above the critical micelle concentration. After introducing some general properties of this type of artificial microswimmer, we focus on two topics: the influence of liquid crystallinity on the swimming behavior and the collective behavior of ensembles of a larger number of droplets. The mesogenic properties are not essential for the basic mechanism of self-propulsion, nevertheless they considerably influence the swimming behavior of the droplets. For instance, the shape of the trajectories strongly depends on whether the droplets are in the nematic or isotropic state. The droplet swimmers are also ideally suited for the study of collective behavior: Microfluidics enables the generation of large numbers of identical swimmers and we can tune their buoyancy. We report on the collective behavior in three-dimensional environments. Supported by the Deutsche Forschungsgemeinschaft (SPP 1726 ``Microswimmers'').

Ideal AFROC and FROC observers.

PubMed

Khurd, Parmeshwar; Liu, Bin; Gindi, Gene

2010-02-01

Detection of multiple lesions in images is a medically important task and free-response receiver operating characteristic (FROC) analyses and its variants, such as alternative FROC (AFROC) analyses, are commonly used to quantify performance in such tasks. However, ideal observers that optimize FROC or AFROC performance metrics have not yet been formulated in the general case. If available, such ideal observers may turn out to be valuable for imaging system optimization and in the design of computer aided diagnosis techniques for lesion detection in medical images. In this paper, we derive ideal AFROC and FROC observers. They are ideal in that they maximize, amongst all decision strategies, the area, or any partial area, under the associated AFROC or FROC curve. Calculation of observer performance for these ideal observers is computationally quite complex. We can reduce this complexity by considering forms of these observers that use false positive reports derived from signal-absent images only. We also consider a Bayes risk analysis for the multiple-signal detection task with an appropriate definition of costs. A general decision strategy that minimizes Bayes risk is derived. With particular cost constraints, this general decision strategy reduces to the decision strategy associated with the ideal AFROC or FROC observer.

Non-ideality by sedimentation velocity of halophilic malate dehydrogenase in complex solvents.

PubMed Central

Solovyova, A; Schuck, P; Costenaro, L; Ebel, C

2001-01-01

We have investigated the potential of sedimentation velocity analytical ultracentrifugation for the measurement of the second virial coefficients of proteins, with the goal of developing a method that allows efficient screening of different solvent conditions. This may be useful for the study of protein crystallization. Macromolecular concentration distributions were modeled using the Lamm equation with the approximation of linear concentration dependencies of the diffusion constant, D = D(o) (1 + k(D)c), and the reciprocal sedimentation coefficient s = s(o)/(1 + k(s)c). We have studied model distributions for their information content with respect to the particle and its non-ideal behavior, developed a strategy for their analysis by direct boundary modeling, and applied it to data from sedimentation velocity experiments on halophilic malate dehydrogenase in complex aqueous solvents containing sodium chloride and 2-methyl-2,4-pentanediol, including conditions near phase separation. Using global modeling for three sets of data obtained at three different protein concentrations, very good estimates for k(s) and s degrees and also for D degrees and the buoyant molar mass were obtained. It was also possible to obtain good estimates for k(D) and the second virial coefficients. Modeling of sedimentation velocity profiles with the non-ideal Lamm equation appears as a good technique to investigate weak inter-particle interactions in complex solvents and also to extrapolate the ideal behavior of the particle. PMID:11566761

Examination of the solution behaviors of the giant inorganic-organic amphiphilic hybrids

NASA Astrophysics Data System (ADS)

Zhang, Baofang

Presently, the self-assembly behaviors of traditional small surfactants and amphiphilic block copolymers are fairly well understood. In comparison, rather little is known about the self-assembly behaviors of the giant inorganic-organic amphiphilic hybrids in solution. It remains a wide open field to explore. Giant inorganic-organic amphiphilic hybrids, consisting of nanoscale inorganic clusters and organic functional groups, represent a novel class of functional hybrid materials. They have unique physical and chemical properties and potential applications in catalysis, electronic, optics, magnetic materials, medicine and biology. Therefore, as emerging building blocks, they have promising prospects in the advanced materials. In this PhD work, several representative giant inorganic-organic amphiphilic hybrids (triangular-shaped polyoxometalate (POM)-containing inorganic/organic amphiphilic hybrids, POM-containing fluorosurfactants hybrids, POM-containing peptide hybrids POM-peptide hybrids and polyhedral oligometric silsesquioxane (POSS)-polystyrene (PS) are chosen for studying their self-assembly behaviors in solution. Based on the knowledge of the physical chemistry, colloid and polymer science, we focus on the mechanism of the self-assembly process, and the morphology control of the supramolecular structures through the internal and external conditions, such as the composition of the giant amphiphilies, molecular architectures, solvent nature, temperature, concentration, and extrally added salts. It is found that the counterion-meditated interactions dominate the self-assembly of triangular-shaped hybrids in acetone/water mixed solutions, due to the highly dominant hydrophilic portions; the solvent-swelling effect, instead of the charge effect, dominates the whole self-assembly process of the POM-containing fluorosurfactants; the analogy between small surfactants and giant amphiphiles POSS-PS allows a rough assessment of the possible morphologies of the

Episodic Future Thinking about the Ideal Self Induces Lower Discounting, Leading to a Decreased Tendency toward Cheating.

PubMed

Wu, Wen-Hsiung; Cheng, Wen; Chiou, Wen-Bin

2017-01-01

Delay discounting refers to a pervasive tendency toward preferring smaller immediate gains over larger future gains. Recent empirical research has shown that episodic future thinking (EFT; i.e., projecting oneself into the future to pre-experience forthcoming events) can reduce the tendency toward discounting. A common tenet of psychological theories of crime is that delinquency results from focusing on short-term gains while failing to consider adequately the longer-term consequences of delinquent behavior. We investigated whether an EFT intervention involving the ideal self could induce lower discounting rates and, as a consequence, reduced delinquency. The results showed that, compared with control participants, participants engaging in EFT, that is, envisaging life events that would be experienced by their ideal selves, exhibited a lower discounting rate in a monetary choice task (Experiments 1 and 2), as well as a decreased tendency to make delinquent choices in imaginary scenarios (Experiment 1) and cheat in a matrix task (Experiment 2). The discounting tendency mediated the relationship between engaging in EFT pertaining to the ideal self and the tendency toward morally questionable behavior (Experiments 1 and 2). The findings of the two experiments indicate that engagement in EFT with a focus on the ideal self is sufficient to induce lower discounting rates, by promoting consideration of distant costs and thus increasing resistance to delinquent involvement and cheating (given the temptation of the immediate benefits that may accrue from such behavior). The current research constitutes an innovative approach to delinquency prevention and the promotion of morality.

Episodic Future Thinking about the Ideal Self Induces Lower Discounting, Leading to a Decreased Tendency toward Cheating

PubMed Central

Wu, Wen-Hsiung; Cheng, Wen; Chiou, Wen-Bin

2017-01-01

Delay discounting refers to a pervasive tendency toward preferring smaller immediate gains over larger future gains. Recent empirical research has shown that episodic future thinking (EFT; i.e., projecting oneself into the future to pre-experience forthcoming events) can reduce the tendency toward discounting. A common tenet of psychological theories of crime is that delinquency results from focusing on short-term gains while failing to consider adequately the longer-term consequences of delinquent behavior. We investigated whether an EFT intervention involving the ideal self could induce lower discounting rates and, as a consequence, reduced delinquency. The results showed that, compared with control participants, participants engaging in EFT, that is, envisaging life events that would be experienced by their ideal selves, exhibited a lower discounting rate in a monetary choice task (Experiments 1 and 2), as well as a decreased tendency to make delinquent choices in imaginary scenarios (Experiment 1) and cheat in a matrix task (Experiment 2). The discounting tendency mediated the relationship between engaging in EFT pertaining to the ideal self and the tendency toward morally questionable behavior (Experiments 1 and 2). The findings of the two experiments indicate that engagement in EFT with a focus on the ideal self is sufficient to induce lower discounting rates, by promoting consideration of distant costs and thus increasing resistance to delinquent involvement and cheating (given the temptation of the immediate benefits that may accrue from such behavior). The current research constitutes an innovative approach to delinquency prevention and the promotion of morality. PMID:28303111

Brain activation upon ideal-body media exposure and peer feedback in late adolescent girls.

PubMed

van der Meulen, Mara; Veldhuis, Jolanda; Braams, Barbara R; Peters, Sabine; Konijn, Elly A; Crone, Eveline A

2017-08-01

Media's prevailing thin-body ideal plays a vital role in adolescent girls' body image development, but the co-occurring impact of peer feedback is understudied. The present study used functional magnetic resonance imaging (fMRI) to test media imagery and peer feedback combinations on neural activity related to thin-body ideals. Twenty-four healthy female late adolescents rated precategorized body sizes of bikini models (too thin or normal), directly followed by ostensible peer feedback (too thin or normal). Consistent with prior studies on social feedback processing, results showed increased brain activity in the dorsal medial prefrontal cortex (dmPFC)/anterior cingulate cortex (ACC) and bilateral insula in incongruent situations: when participants rated media models' body size as normal while peer feedback indicated the models as too thin (or vice versa). This effect was stronger for girls with lower self-esteem. A subsequent behavioral study (N = 34 female late adolescents, separate sample) demonstrated that participants changed behavior in the direction of the peer feedback: precategorized normal sized models were rated as too thin more often after receiving too thin peer feedback. This suggests that the neural responses upon peer feedback may influence subsequent choice. Our results show that media-by-peer interactions have pronounced effects on girls' body ideals.

Induced drag ideal efficiency factor of arbitrary lateral-vertical wing forms

NASA Technical Reports Server (NTRS)

Deyoung, J.

1980-01-01

A relatively simple equation is presented for estimating the induced drag ideal efficiency factor e for arbitrary cross sectional wing forms. This equation is based on eight basic but varied wing configurations which have exact solutions. The e function which relates the basic wings is developed statistically and is a continuous function of configuration geometry. The basic wing configurations include boxwings shaped as a rectangle, ellipse, and diamond; the V-wing; end-plate wing; 90 degree cruciform; circle dumbbell; and biplane. Example applications of the e equations are made to many wing forms such as wings with struts which form partial span rectangle dumbbell wings; bowtie, cruciform, winglet, and fan wings; and multiwings. Derivations are presented in the appendices of exact closed form solutions found of e for the V-wing and 90 degree cruciform wing and for an asymptotic solution for multiwings.

Fitting measurement models to vocational interest data: are dominance models ideal?

PubMed

Tay, Louis; Drasgow, Fritz; Rounds, James; Williams, Bruce A

2009-09-01

In this study, the authors examined the item response process underlying 3 vocational interest inventories: the Occupational Preference Inventory (C.-P. Deng, P. I. Armstrong, & J. Rounds, 2007), the Interest Profiler (J. Rounds, T. Smith, L. Hubert, P. Lewis, & D. Rivkin, 1999; J. Rounds, C. M. Walker, et al., 1999), and the Interest Finder (J. E. Wall & H. E. Baker, 1997; J. E. Wall, L. L. Wise, & H. E. Baker, 1996). Item response theory (IRT) dominance models, such as the 2-parameter and 3-parameter logistic models, assume that item response functions (IRFs) are monotonically increasing as the latent trait increases. In contrast, IRT ideal point models, such as the generalized graded unfolding model, have IRFs that peak where the latent trait matches the item. Ideal point models are expected to fit better because vocational interest inventories ask about typical behavior, as opposed to requiring maximal performance. Results show that across all 3 interest inventories, the ideal point model provided better descriptions of the response process. The importance of specifying the correct item response model for precise measurement is discussed. In particular, scores computed by a dominance model were shown to be sometimes illogical: individuals endorsing mostly realistic or mostly social items were given similar scores, whereas scores based on an ideal point model were sensitive to which type of items respondents endorsed.

Simple equations to simulate closed-loop recycling liquid-liquid chromatography: Ideal and non-ideal recycling models.

PubMed

Kostanyan, Artak E

2015-12-04

The ideal (the column outlet is directly connected to the column inlet) and non-ideal (includes the effects of extra-column dispersion) recycling equilibrium-cell models are used to simulate closed-loop recycling counter-current chromatography (CLR CCC). Simple chromatogram equations for the individual cycles and equations describing the transport and broadening of single peaks and complex chromatograms inside the recycling closed-loop column for ideal and non-ideal recycling models are presented. The extra-column dispersion is included in the theoretical analysis, by replacing the recycling system (connecting lines, pump and valving) by a cascade of Nec perfectly mixed cells. To evaluate extra-column contribution to band broadening, two limiting regimes of recycling are analyzed: plug-flow, Nec→∞, and maximum extra-column dispersion, Nec=1. Comparative analysis of ideal and non-ideal models has shown that when the volume of the recycling system is less than one percent of the column volume, the influence of the extra-column processes on the CLR CCC separation may be neglected. Copyright © 2015 Elsevier B.V. All rights reserved.

The Impact of Ethical Ideology on Moral Behavior.

ERIC Educational Resources Information Center

Nye, Judith; Forsyth, Donelson R.

To examine the impact of ethical ideology, i.e., situationism (high relativism and idealism), subjectivism (high relativism/low idealism), absolutism (low relativism/high idealism), and exceptionism (low relativism and idealism), as well as the saliency of moral norms, and the situational consequences on moral behavior, 112 male and female college…

Minimum-sized ideal reactor for continuous alcohol fermentation using immobilized microorganism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamane, T.; Shimizu, S.

Recently, alcohol fermentation has gained considerable attention with the aim of lowering its production cost in the production processes of both fuel ethanol and alcoholic beverages. The over-all cost is a summation of costs of various subsystems such as raw material (sugar, starch, and cellulosic substances) treatment, fermentation process, and alcohol separation from water solutions; lowering the cost of the fermentation processes is very important in lowering the total cost. Several new techniques have been developed for economic continuous ethanol production, use of a continuous wine fermentor with no mechanical stirring, cell recycle combined with continuous removal of ethanol undermore » vaccum, a technique involving a bed of yeast admixed with an inert carrier, and use of immobilized yeast reactors in packed-bed column and in a three-stage double conical fluidized-bed bioreactor. All these techniques lead to increases more or less, in reactor productivity, which in turn result in the reduction of the reactor size for a given production rate and a particular conversion. Since an improvement in the fermentation process often leads to a reduction of fermentor size and hence, a lowering of the initial construction cost, it is important to theoretically arrive at a solution to what is the minimum-size setup of ideal reactors from the viewpoint of liquid backmixing. In this short communication, the minimum-sized ideal reactor for continuous alcohol fermentation using immobilized cells will be specifically discussed on the basis of a mathematical model. The solution will serve for designing an optimal bioreactor. (Refs. 26).« less

Media exposure, internalization of the thin ideal, and body dissatisfaction: comparing Asian American and European American college females.

PubMed

Nouri, Mahsa; Hill, Laura G; Orrell-Valente, Joan K

2011-09-01

Internalization of the thin ideal mediates the media exposure-body dissatisfaction relation in young adult European American females. There is little related research on Asian Americans. We used structural equations modeling to test: (1) whether media exposure was associated with body dissatisfaction in Asian American young adult females, (2) internalization of the thin ideal mediated any such association, and (3) whether the mediational model provided equivalent fit for European American and Asian American samples. Participants were 287 college females (154 Asian Americans, 133 European Americans). Internalization of the thin ideal explained the media exposure-body dissatisfaction association equally well for both groups. Results suggest that Asian Americans may be employing unhealthy weight control behaviors, and may be prone to developing eating disorders, at rates similar to European American young adult females. Clinicians need to screen carefully for body dissatisfaction, unhealthy weight control behaviors, and eating disorders in Asian American females. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaporation Behavior and Characterization of Eutectic Solvent and Ibuprofen Eutectic Solution.

PubMed

Phaechamud, Thawatchai; Tuntarawongsa, Sarun; Charoensuksai, Purin

2016-10-01

Liquid eutectic system of menthol and camphor has been reported as solvent and co-solvent for some drug delivery systems. However, surprisingly, the phase diagram of menthol-camphor eutectic has not been reported previously. The evaporation behavior, physicochemical, and thermal properties of this liquid eutectic and ibuprofen eutectic solution were characterized in this study. Differential scanning calorimetry (DSC) analysis indicated that a eutectic point of this system was near to 1:1 menthol/camphor and its eutectic temperature was -1°C. The solubility of ibuprofen in this eutectic was 282.11 ± 6.67 mg mL(-1) and increased the drug aqueous solubility fourfold. The shift of wave number from Fourier transform infrared spectroscopy (FTIR) indicated the hydrogen bonding of each compound in eutectic mixture. The weight loss from thermogravimetric analysis of menthol and camphor related to the evaporation and sublimation, respectively. Menthol demonstrated a lower apparent sublimation rate than camphor, and the evaporation rate of eutectic solvent was lower than the sublimation rate of camphor but higher than the evaporation of menthol. The evaporation rate of the ibuprofen eutectic solution was lower than that of the eutectic solvent because ibuprofen did not sublimate. This eutectic solvent prolonged the ibuprofen release with diffusion control. Thus, the beneficial information for thermal behavior and related properties of eutectic solvent comprising menthol-camphor and ibuprofen eutectic solution was attained successfully. The rather low evaporation of eutectic mixture will be beneficial for investigation and tracking the mechanism of transformation from nanoemulsion into nanosuspension in the further study using eutectic as oil phase.

The decisive role of free water in determining homogenous ice nucleation behavior of aqueous solutions

PubMed Central

Wang, Qiang; Zhao, Lishan; Li, Chenxi; Cao, Zexian

2016-01-01

It is a challenging issue to quantitatively characterize how the solute and pressure affect the homogeneous ice nucleation in a supercooled solution. By measuring the glass transition behavior of solutions, a universal feature of water-content dependence of glass transition temperature is recognized, which can be used to quantify hydration water in solutions. The amount of free water can then be determined for water-rich solutions, whose mass fraction, Xf, is found to serve as a universal relevant parameter for characterizing the homogeneous ice nucleation temperature, the meting temperature of primary ice, and even the water activity of solutions of electrolytes and smaller organic molecules. Moreover, the effects of hydrated solute and pressure on ice nucleation is comparable, and the pressure, when properly scaled, can be incorporated into the universal parameter Xf. These results help establish the decisive role of free water in determining ice nucleation and other relevant properties of aqueous solutions. PMID:27225427

Dissolution and solubility behavior of fenofibrate in sodium lauryl sulfate solutions.

PubMed

Granero, Gladys E; Ramachandran, Chandrasekharan; Amidon, Gordon L

2005-10-01

The solubility of fenofibrate in pH 6.8 McIlvaine buffers containing varying concentrations of sodium lauryl sulfate was determined. The dissolution behavior of fenofibrate was also examined in the same solutions with rotating disk experiments. It was observed that the enhancement in intrinsic dissolution rate was approximately 500-fold and the enhancement in solubility was approximately 2000-fold in a pH 6.8 buffer containing 2% (w/v) sodium lauryl sulfate compared to that in buffer alone. The micellar solubilization equilibrium coefficient (k*) was estimated from the solubility data and found to be 30884+/-213 L/mol. The diffusivity for the free solute, 7.15x10(-6) cm2/s, was calculated using Schroeder's additive molal volume estimates and Hayduk-Laurie correlation. The diffusivity of the drug-loaded micelle, estimated from the experimental solubility and dissolution data and the calculated value for free solute diffusivity, was 0.86x10(-6) cm2/s. Thus, the much lower enhancement in dissolution of fenofibrate compared to its enhancement in solubility in surfactant solutions appears to be consistent with the contribution to the total transport due to enhanced micellar solubilization as well as a large decrease (approximately 8-fold) in the diffusivity of the drug-loaded micelle.

Large time behavior of entropy solutions to one-dimensional unipolar hydrodynamic model for semiconductor devices

NASA Astrophysics Data System (ADS)

Huang, Feimin; Li, Tianhong; Yu, Huimin; Yuan, Difan

2018-06-01

We are concerned with the global existence and large time behavior of entropy solutions to the one-dimensional unipolar hydrodynamic model for semiconductors in the form of Euler-Poisson equations in a bounded interval. In this paper, we first prove the global existence of entropy solution by vanishing viscosity and compensated compactness framework. In particular, the solutions are uniformly bounded with respect to space and time variables by introducing modified Riemann invariants and the theory of invariant region. Based on the uniform estimates of density, we further show that the entropy solution converges to the corresponding unique stationary solution exponentially in time. No any smallness condition is assumed on the initial data and doping profile. Moreover, the novelty in this paper is about the unform bound with respect to time for the weak solutions of the isentropic Euler-Poisson system.

Long term dietary methoxychlor exposure in rats increases sodium solution consumption but has few effects on other sexually dimorphic behaviors.

PubMed

Flynn, K M; Delclos, K B; Newbold, R R; Ferguson, S A

2005-09-01

Methoxychlor is an insecticide with estrogen-like activity, thus exposure during development might cause sexually dimorphic behavioral alterations. To evaluate this, pregnant rats consumed diets containing 0, 10, 100 or 1000 ppm methoxychlor from gestational day 7, and offspring continued on these diets until postnatal day (PND) 77. Assessments of sexually dimorphic behaviors in offspring indicated that intake of a 3.0% sodium chloride solution was significantly increased (41%) in males and females of the 1000 ppm group. No treatment group differed from controls in open field nor running wheel activity, play behavior, nor 0.3% saccharin solution intake. Offspring of the 1000 ppm group showed significantly decreased body weight, reaching 17% less than controls at PND 77, but not clearly related to their salt solution intake. During pregnancy, 1000 ppm dams consumed 23% less food and weighed 10% less than controls, but this did not affect litter outcomes. These results indicate that in rodents, developmental and chronic exposure to dietary methoxychlor alters the sexually dimorphic behavior of salt-solution intake in young adults of both sexes. Similar behavioral alterations with other xenoestrogens, and the potential for interactions among xenoestrogens, suggest that this report may minimize the true effects of dietary methoxychlor exposure.

Solid-Phase and Oscillating Solution Crystallization Behavior of (+)- and (-)-N-Methylephedrine.

PubMed

Tulashie, Samuel Kofi; Polenske, Daniel; Seidel-Morgenstern, Andreas; Lorenz, Heike

2016-11-01

This work involves the study of the solid-phase and solution crystallization behavior of the N-methylephedrine enantiomers. A systematic investigation of the melt phase diagram of the enantiomeric N-methylephedrine system was performed considering polymorphism. Two monotropically related modifications of the enantiomer were found. Solubilities and the ternary solubility phase diagrams of N-methylephedrine enantiomers in 2 solvents [isopropanol:water, 1:3 (Vol) and (2R, 3R)-diethyl tartrate] were determined in the temperature ranges between 15°C and 25°C, and 25°C and 40°C, respectively. Preferential nucleation and crystallization experiments at higher supersaturation leading to an unusual oscillatory crystallization behavior as well as a successful preferential crystallization experiment at lower supersaturation are presented and discussed. Copyright © 2016. Published by Elsevier Inc.

Dry solution to a sticky problem

PubMed Central

KARP, JEFFREY M.; LANGER, ROBERT

2011-01-01

Sticking plasters revolutionized the protection of minor wounds, but they’re not ideal for fragile skin. A material that mimics the adhesive properties of certain beetles’ feet might provide a solution. PMID:21886155

Behavior of neutral solutes in pressurized flow driven electrochromatography using a mixed stationary phase of ODS and anion-exchange.

PubMed

Kitagawa, Shinya; Tsuda, Takao

2003-05-02

The behavior of neutral sample solutes in pressurized flow driven electrochromatography using a mixed stationary phase, which consisted of ODS and anion-exchange (ODS-SAX), was studied. Applications of both positive and negative voltage on a column induced increases in retention factors of sample solutes. The direction of an electroosmotic flow under applications of positive and negative voltage were the same, therefore, the sign of the surface charge density under positive and negative voltage was opposite. We proposed a new equation for the relationship between applied voltage and surface charge density, and the practical electroosmotic flow conformed to this equation. Studying the electroosmotic flow using our proposed equation revealed that the applied negative voltage accelerates the protonation of the quaternary ammonium group and dissociation of the silanol group on packing materials. The retention behavior of a neutral solute was affected by the existence of the charged functional groups. We propose that this phenomenon is applicable to the control of the retention behavior of a sample solute using an electric field.

Ultrasonic density measurement cell design and simulation of non-ideal effects.

PubMed

Higuti, Ricardo Tokio; Buiochi, Flávio; Adamowski, Júlio Cezar; de Espinosa, Francisco Montero

2006-07-01

This paper presents a theoretical analysis of a density measurement cell using an unidimensional model composed by acoustic and electroacoustic transmission lines in order to simulate non-ideal effects. The model is implemented using matrix operations, and is used to design the cell considering its geometry, materials used in sensor assembly, range of liquid sample properties and signal analysis techniques. The sensor performance in non-ideal conditions is studied, considering the thicknesses of adhesive and metallization layers, and the effect of residue of liquid sample which can impregnate on the sample chamber surfaces. These layers are taken into account in the model, and their effects are compensated to reduce the error on density measurement. The results show the contribution of residue layer thickness to density error and its behavior when two signal analysis methods are used.

Behavior of a semi-infinite ice cover under periodic dynamic impact

NASA Astrophysics Data System (ADS)

Tkacheva, L. A.

2017-07-01

Oscillations of a semi-infinite ice cover in an ideal incompressible liquid of finite depth under local time-periodic axisymmetric load are considered. The ice cover is simulated by a thin elastic plate of constant thickness. An analytical solution of the problem is obtained using the Wiener-Hopf method. The asymptotic behavior of the amplitudes of oscillations of the plate and the liquid in the far field is studied. It is shown that the propagation of waves in the far field is uneven: in some directions, the waves propagate with a significantly greater amplitude.

A thermoelastic transversely isotropic thick walled cylinder/disk application: An analytical solution and study

NASA Technical Reports Server (NTRS)

Arnold, S. M.

1989-01-01

A continuum theory is utilized to represent the thermoelastic behavior of a thick walled composite cylinder that can be idealized as transversely isotropic. A multiaxial statement of the constitutive theory employed is presented, as well as the out of the plane of isotropy, plane stress, and plane strain reductions. The derived analytical solution presented is valid for a cylindrical tube or thin disk with a concentric hole, subjected to internal and/or external pressure and a general radial temperature distribution. A specific problem examined is that of a thick walled cylinder subjected to an internal and external pressure loading and a linear radial temperature distribution. The results are expressed in nondimensional form and the effects on the response behavior are examined for various material properties, fiber orientation and types of loadings.

Perennial flow through convergent hillslopes explains chemodynamic solute behavior in a shale headwater catchment

NASA Astrophysics Data System (ADS)

Herndon, E.; Steinhoefel, G.; Dere, A. L. D.; Sullivan, P. L.

2017-12-01

Streams experience changing hydrologic connectivity to heterogeneous water sources under different flow regimes. It remains unclear how seasonal flow paths link these different sources and regulate concentration-discharge behavior. Previous research at the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) in central Pennsylvania, USA identified chemostatic solutes (e.g., K, Mg, Na, Cl) whose concentrations varied little across a wide range of discharge values and chemodynamic solutes (e.g., Fe and Mn) whose concentrations decreased sharply with increasing stream discharge. To elucidate inputs to the stream when concentrations of chemodynamic solutes were high, we investigated stream water and shallow groundwater (< 4 m) chemistry at the SSHCZO in early autumn when discharge was negligible. The stream consisted of isolated puddles that were chemically variable along the length of the channel but similar to underlying shallow groundwater. Chemodynamic solute concentrations in the stream and groundwater were high in the upper catchment but decreased by an order of magnitude towards the outlet. In contrast, chemostatic solute concentrations varied little. Groundwater was minimally connected to the stream in an area of upwelling near the stream headwaters; however, the water table remained over a meter below the stream bed along the rest of the channel. We conclude that well water sampled from the upper catchment is young, shallow interflow that upwells to generate metal-rich stream headwaters during the dry season. High concentrations of chemodynamic solutes measured during low discharge occur when metal-rich headwaters are flushed to the catchment outlet during periodic rain events. Interflow during the dry season originates from water that infiltrates through organic-rich swales; thus, metals in the stream at low flow are ultimately derived from convergent hillslopes where biological processes have concentrated chemodynamic elements. We infer that

On the asymptotic behavior of radial entire solutions for the equation (-Δ)3u = up in Rn

NASA Astrophysics Data System (ADS)

Tai, Nguyen Tien

2018-03-01

Our main task in this note is to prove the existence and to classify the exact growth at infinity of radial positive C6-solutions of (- Δ) 3 u =up in Rn, where n ⩾ 15 and p is bounded from below by the sixth-order Joseph-Lundgren exponent. Following the main work of Winkler, we introduce the sub- and super-solution method and comparison principle to conclude the asymptotic behavior of solutions.

Numerical Simulation of the Freeze-Thaw Behavior of Mortar Containing Deicing Salt Solution

PubMed Central

Esmaeeli, Hadi S.; Farnam, Yaghoob; Bentz, Dale P.; Zavattieri, Pablo D.; Weiss, Jason

2016-01-01

This paper presents a one-dimensional finite difference model that is developed to describe the freeze-thaw behavior of an air-entrained mortar containing deicing salt solution. A phenomenological model is used to predict the temperature and the heat flow for mortar specimens during cooling and heating. Phase transformations associated with the freezing/melting of water/ice or transition of the eutectic solution from liquid to solid are included in this phenomenological model. The lever rule is used to calculate the quantity of solution that undergoes the phase transformation, thereby simulating the energy released/absorbed during phase transformation. Undercooling and pore size effects are considered in the numerical model. To investigate the effect of pore size distribution, this distribution is considered using the Gibbs-Thomson equation in a saturated mortar specimen. For an air-entrained mortar, the impact of considering pore size (and curvature) on freezing was relatively insignificant; however the impact of pore size is much more significant during melting. The fluid inside pores smaller than 5 nm (i.e., gel pores) has a relatively small contribution in the macroscopic freeze-thaw behavior of mortar specimens within the temperature range used in this study (i.e., +24 °C to −35 °C), and can therefore be neglected for the macroscopic freeze-thaw simulations. A heat sink term is utilized to simulate the heat dissipation during phase transformations. Data from experiments performed using a low-temperature longitudinal guarded comparative calorimeter (LGCC) on mortar specimens fully saturated with various concentration NaCl solutions or partially saturated with water is compared to the numerical results and a promising agreement is generally obtained. PMID:28082830

Numerical Simulation of the Freeze-Thaw Behavior of Mortar Containing Deicing Salt Solution.

PubMed

Esmaeeli, Hadi S; Farnam, Yaghoob; Bentz, Dale P; Zavattieri, Pablo D; Weiss, Jason

2017-02-01

This paper presents a one-dimensional finite difference model that is developed to describe the freeze-thaw behavior of an air-entrained mortar containing deicing salt solution. A phenomenological model is used to predict the temperature and the heat flow for mortar specimens during cooling and heating. Phase transformations associated with the freezing/melting of water/ice or transition of the eutectic solution from liquid to solid are included in this phenomenological model. The lever rule is used to calculate the quantity of solution that undergoes the phase transformation, thereby simulating the energy released/absorbed during phase transformation. Undercooling and pore size effects are considered in the numerical model. To investigate the effect of pore size distribution, this distribution is considered using the Gibbs-Thomson equation in a saturated mortar specimen. For an air-entrained mortar, the impact of considering pore size (and curvature) on freezing was relatively insignificant; however the impact of pore size is much more significant during melting. The fluid inside pores smaller than 5 nm (i.e., gel pores) has a relatively small contribution in the macroscopic freeze-thaw behavior of mortar specimens within the temperature range used in this study (i.e., +24 °C to -35 °C), and can therefore be neglected for the macroscopic freeze-thaw simulations. A heat sink term is utilized to simulate the heat dissipation during phase transformations. Data from experiments performed using a low-temperature longitudinal guarded comparative calorimeter (LGCC) on mortar specimens fully saturated with various concentration NaCl solutions or partially saturated with water is compared to the numerical results and a promising agreement is generally obtained.

The effect of solute additions on the steady-state creep behavior of dispersion-strengthened aluminum.

NASA Technical Reports Server (NTRS)

Reynolds, G. H.; Lenel, F. V.; Ansell, G. S.

1971-01-01

The effect of solute additions on the steady-state creep behavior of coarse-grained dispersion-strengthened aluminum alloys was studied. Recrystallized dispersion-strengthened solid solutions were found to have stress and temperature sensitivities quite unlike those observed in single-phase solid solutions having the same composition and grain size. The addition of magnesium or copper to the matrix of a recrystallized dispersion-strengthened aluminum causes a decrease in the steady-state creep rate which is much smaller than that caused by similar amounts of solute in single-phase solid solutions. All alloys exhibited essentially a 4.0 power stress exponent in agreement with the model of Ansell and Weertman. The activation energy for steady-state creep in dispersion-strengthened Al-Mg alloys, as well as the stress dependence, was in agreement with the physical model of dislocation climb over the dispersed particles.

Convergence behavior of idealized convection-resolving simulations of summertime deep moist convection over land

NASA Astrophysics Data System (ADS)

Panosetti, Davide; Schlemmer, Linda; Schär, Christoph

2018-05-01

Convection-resolving models (CRMs) can explicitly simulate deep convection and resolve interactions between convective updrafts. They are thus increasingly used in numerous weather and climate applications. However, the truncation of the continuous energy cascade at scales of O (1 km) poses a serious challenge, as in kilometer-scale simulations the size and properties of the simulated convective cells are often determined by the horizontal grid spacing (Δ x ).In this study, idealized simulations of deep moist convection over land are performed to assess the convergence behavior of a CRM at Δ x = 8, 4, 2, 1 km and 500 m. Two types of convergence estimates are investigated: bulk convergence addressing domain-averaged and integrated variables related to the water and energy budgets, and structural convergence addressing the statistics and scales of individual clouds and updrafts. Results show that bulk convergence generally begins at Δ x =4 km, while structural convergence is not yet fully achieved at the kilometer scale, despite some evidence that the resolution sensitivity of updraft velocities and convective mass fluxes decreases at finer resolution. In particular, at finer grid spacings the maximum updraft velocity generally increases, and the size of the smallest clouds is mostly determined by Δ x . A number of different experiments are conducted, and it is found that the presence of orography and environmental vertical wind shear yields more energetic structures at scales much larger than Δ x , sometimes reducing the resolution sensitivity. Overall the results lend support to the use of kilometer-scale resolutions in CRMs, despite the inability of these models to fully resolve the associated cloud field.

Active ideal sedimentation: exact two-dimensional steady states.

PubMed

Hermann, Sophie; Schmidt, Matthias

2018-02-28

We consider an ideal gas of active Brownian particles that undergo self-propelled motion and both translational and rotational diffusion under the influence of gravity. We solve analytically the corresponding Smoluchowski equation in two space dimensions for steady states. The resulting one-body density is given as a series, where each term is a product of an orientation-dependent Mathieu function and a height-dependent exponential. A lower hard wall is implemented as a no-flux boundary condition. Numerical evaluation of the suitably truncated analytical solution shows the formation of two different spatial regimes upon increasing Peclet number. These regimes differ in their mean particle orientation and in their variation of the orientation-averaged density with height.

Modeling of non-ideal hard permanent magnets with an affine-linear model, illustrated for a bar and a horseshoe magnet

NASA Astrophysics Data System (ADS)

Glane, Sebastian; Reich, Felix A.; Müller, Wolfgang H.

2017-11-01

This study is dedicated to continuum-scale material modeling of isotropic permanent magnets. An affine-linear extension to the commonly used ideal hard model for permanent magnets is proposed, motivated, and detailed. In order to demonstrate the differences between these models, bar and horseshoe magnets are considered. The structure of the boundary value problem for the magnetic field and related solution techniques are discussed. For the ideal model, closed-form analytical solutions were obtained for both geometries. Magnetic fields of the boundary value problems for both models and differently shaped magnets were computed numerically by using the boundary element method. The results show that the character of the magnetic field is strongly influenced by the model that is used. Furthermore, it can be observed that the shape of an affine-linear magnet influences the near-field significantly. Qualitative comparisons with experiments suggest that both the ideal and the affine-linear models are relevant in practice, depending on the magnetic material employed. Mathematically speaking, the ideal magnetic model is a special case of the affine-linear one. Therefore, in applications where knowledge of the near-field is important, the affine-linear model can yield more accurate results—depending on the magnetic material.

Too hot to handle? Analytic solutions for massive neutrino or warm dark matter cosmologies

NASA Astrophysics Data System (ADS)

Slepian, Zachary; Portillo, Stephen K. N.

2018-05-01

We obtain novel closed-form solutions to the Friedmann equation for cosmological models containing a component whose equation of state is that of radiation (w = 1/3) at early times and that of cold pressureless matter (w = 0) at late times. The equation of state smoothly transitions from the early to late-time behavior and exactly describes the evolution of a species with a Dirac Delta function distribution in momentum magnitudes |p_0| (i.e. all particles have the same |p_0|). Such a component, here termed "hot matter", is an approximate model for both neutrinos and warm dark matter. We consider it alone and in combination with cold matter and with radiation, also obtaining closed-form solutions for the growth of super-horizon perturbations in each case. The idealized model recovers t(a) to better than 1.5% accuracy for all a relative to a Fermi-Dirac distribution (as describes neutrinos). We conclude by adding the second moment of the distribution to our exact solution and then generalizing to include all moments of an arbitrary momentum distribution in a closed-form solution.

Statistical mechanics of an ideal active fluid confined in a channel

NASA Astrophysics Data System (ADS)

Wagner, Caleb; Baskaran, Aparna; Hagan, Michael

The statistical mechanics of ideal active Brownian particles (ABPs) confined in a channel is studied by obtaining the exact solution of the steady-state Smoluchowski equation for the 1-particle distribution function. The solution is derived using results from the theory of two-way diffusion equations, combined with an iterative procedure that is justified by numerical results. Using this solution, we quantify the effects of confinement on the spatial and orientational order of the ensemble. Moreover, we rigorously show that both the bulk density and the fraction of particles on the channel walls obey simple scaling relations as a function of channel width. By considering a constant-flux steady state, an effective diffusivity for ABPs is derived which shows signatures of the persistent motion that characterizes ABP trajectories. Finally, we discuss how our techniques generalize to other active models, including systems whose activity is modeled in terms of an Ornstein-Uhlenbeck process.

Ideal regularization for learning kernels from labels.

PubMed

Pan, Binbin; Lai, Jianhuang; Shen, Lixin

2014-08-01

In this paper, we propose a new form of regularization that is able to utilize the label information of a data set for learning kernels. The proposed regularization, referred to as ideal regularization, is a linear function of the kernel matrix to be learned. The ideal regularization allows us to develop efficient algorithms to exploit labels. Three applications of the ideal regularization are considered. Firstly, we use the ideal regularization to incorporate the labels into a standard kernel, making the resulting kernel more appropriate for learning tasks. Next, we employ the ideal regularization to learn a data-dependent kernel matrix from an initial kernel matrix (which contains prior similarity information, geometric structures, and labels of the data). Finally, we incorporate the ideal regularization to some state-of-the-art kernel learning problems. With this regularization, these learning problems can be formulated as simpler ones which permit more efficient solvers. Empirical results show that the ideal regularization exploits the labels effectively and efficiently. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intuitionistic fuzzy n-fold KU-ideal of KU-algebra

NASA Astrophysics Data System (ADS)

Mostafa, Samy M.; Kareem, Fatema F.

2018-05-01

In this paper, we apply the notion of intuitionistic fuzzy n-fold KU-ideal of KU-algebra. Some types of ideals such as intuitionistic fuzzy KU-ideal, intuitionistic fuzzy closed ideal and intuitionistic fuzzy n-fold KU-ideal are studied. Also, the relations between intuitionistic fuzzy n-fold KU-ideal and intuitionistic fuzzy KU-ideal are discussed. Furthermore, a few results of intuitionistic fuzzy n-fold KU-ideals of a KU-algebra under homomorphism are discussed.

Ideal Magnetic Dipole Scattering

NASA Astrophysics Data System (ADS)

Feng, Tianhua; Xu, Yi; Zhang, Wei; Miroshnichenko, Andrey E.

2017-04-01

We introduce the concept of tunable ideal magnetic dipole scattering, where a nonmagnetic nanoparticle scatters light as a pure magnetic dipole. High refractive index subwavelength nanoparticles usually support both electric and magnetic dipole responses. Thus, to achieve ideal magnetic dipole scattering one has to suppress the electric dipole response. Such a possibility was recently demonstrated for the so-called anapole mode, which is associated with zero electric dipole scattering. By spectrally overlapping the magnetic dipole resonance with the anapole mode, we achieve ideal magnetic dipole scattering in the far field with tunable strong scattering resonances in the near infrared spectrum. We demonstrate that such a condition can be realized at least for two subwavelength geometries. One of them is a core-shell nanosphere consisting of a Au core and silicon shell. It can be also achieved in other geometries, including nanodisks, which are compatible with current nanofabrication technology.

IDEAL characterization of isometry classes of FLRW and inflationary spacetimes

NASA Astrophysics Data System (ADS)

Canepa, Giovanni; Dappiaggi, Claudio; Khavkine, Igor

2018-02-01

In general relativity, an IDEAL (Intrinsic, Deductive, Explicit, ALgorithmic) characterization of a reference spacetime metric g 0 consists of a set of tensorial equations T[g]  =  0, constructed covariantly out of the metric g, its Riemann curvature and their derivatives, that are satisfied if and only if g is locally isometric to the reference spacetime metric g 0. The same notion can be extended to also include scalar or tensor fields, where the equations T[g, φ]=0 are allowed to also depend on the extra fields ϕ. We give the first IDEAL characterization of cosmological FLRW spacetimes, with and without a dynamical scalar (inflaton) field. We restrict our attention to what we call regular geometries, which uniformly satisfy certain identities or inequalities. They roughly split into the following natural special cases: constant curvature spacetime, Einstein static universe, and flat or curved spatial slices. We also briefly comment on how the solution of this problem has implications, in general relativity and inflation theory, for the construction of local gauge invariant observables for linear cosmological perturbations and for stability analysis.

Multiscale Roughness Influencing on Transport Behavior of Passive Solute through a Single Self-affine Fracture

NASA Astrophysics Data System (ADS)

Dou, Z.

2017-12-01

In this study, the influence of multi-scale roughness on transport behavior of the passive solute through the self-affine fracture was investigated. The single self-affine fracture was constructed by the successive random additions (SRA) and the fracture roughness was decomposed into two different scales (i.e. large-scale primary roughness and small-scale secondary roughness) by the Wavelet analysis technique. The fluid flow in fractures, which was characterized by the Forchheimer's law, showed the non-linear flow behaviors such as eddies and tortuous streamlines. The results indicated that the small-scale secondary roughness was primarily responsible for the non-linear flow behaviors. The direct simulations of asymptotic passive solute transport represented the Non-Fickian transport characteristics (i.e. early arrivals and long tails) in breakthrough curves (BTCs) and residence time distributions (RTDs) with and without consideration of the secondary roughness. Analysis of multiscale BTCs and RTDs showed that the small-scale secondary roughness played a significant role in enhancing the Non-Fickian transport characteristics. We found that removing small-scale secondary roughness led to the lengthening arrival and shortening tail. The peak concentration in BTCs decreased as the secondary roughness was removed, implying that the secondary could also enhance the solute dilution. The estimated BTCs by the Fickian advection-dispersion equation (ADE) yielded errors which decreased with the small-scale secondary roughness being removed. The mobile-immobile model (MIM) was alternatively implemented to characterize the Non-Fickian transport. We found that the MIM was more capable of estimating Non-Fickian BTCs. The small-scale secondary roughness resulted in the decreasing mobile domain fraction and the increasing mass exchange rate between immobile and mobile domains. The estimated parameters from the MIM could provide insight into the inherent mechanism of roughness

Comparison of the Electrochemical Behavior of Ti and Nanostructured Ti-Coated AISI 304 Stainless Steel in Strongly Acidic Solutions

NASA Astrophysics Data System (ADS)

Attarzadeh, Farid Reza; Elmkhah, Hassan; Fattah-Alhosseini, Arash

2017-02-01

In this study, the electrochemical behaviors of pure titanium (Ti) and nanostructured (NS) Ti-coated AISI 304 stainless steel (SS) in strongly acidic solutions of H2SO4 were investigated and compared. A type of physical vapor deposition method, cathodic arc evaporation, was applied to deposit NS Ti on 304 SS. Scanning electron microscope and X-ray diffraction were used to characterize surface coating morphology. Potentiodynamic polarization, electrochemical impedance spectroscopy, and Mott-Schottky (M-S) analysis were used to evaluate the passive behavior of the samples. Electrochemical measurements revealed that the passive behavior of NS Ti coating was better than that of pure Ti in 0.1 and 0.01 M H2SO4 solutions. M-S analysis indicated that the passive films behaved as n-type semiconductors in H2SO4 solutions and the deposition method did not affect the semiconducting type of passive films formed on the coated samples. In addition, this analysis showed that the NS Ti coating had lower donor densities. Finally, all electrochemical tests showed that the passive behavior of the Ti-coated samples was superior, mainly due to the formation of thicker, yet less defective passive films.

Ideal men: masculinity and decline in seventeenth-century Spain.

PubMed

Lehfeldt, Elizabeth A

2008-01-01

This article examines how the experience and critique of their country's decline led Spaniards to craft a distinct discourse of masculinity in the seventeenth century. As they self-consciously examined Spain's crisis and offered political and economic solutions, these same writers also offered a scathing critique of standards of masculinity. Using the figure of the ideal nobleman as a case study, the article examines how moralists, arbitristas, and hagiographers constructed a dynamic code of manhood linked to questions of productivity, male chastity, and military performance. Further, it argues that this discourse was ultimately nostalgic and failed to adapt itself to the circumstances of the seventeenth century.

The escape of high explosive products: An exact-solution problem for verification of hydrodynamics codes

DOE PAGES

Doebling, Scott William

2016-10-22

This paper documents the escape of high explosive (HE) products problem. The problem, first presented by Fickett & Rivard, tests the implementation and numerical behavior of a high explosive detonation and energy release model and its interaction with an associated compressible hydrodynamics simulation code. The problem simulates the detonation of a finite-length, one-dimensional piece of HE that is driven by a piston from one end and adjacent to a void at the other end. The HE equation of state is modeled as a polytropic ideal gas. The HE detonation is assumed to be instantaneous with an infinitesimal reaction zone. Viamore » judicious selection of the material specific heat ratio, the problem has an exact solution with linear characteristics, enabling a straightforward calculation of the physical variables as a function of time and space. Lastly, implementation of the exact solution in the Python code ExactPack is discussed, as are verification cases for the exact solution code.« less

Improved Classification of Mammograms Following Idealized Training

PubMed Central

Hornsby, Adam N.; Love, Bradley C.

2014-01-01

People often make decisions by stochastically retrieving a small set of relevant memories. This limited retrieval implies that human performance can be improved by training on idealized category distributions (Giguère & Love, 2013). Here, we evaluate whether the benefits of idealized training extend to categorization of real-world stimuli, namely classifying mammograms as normal or tumorous. Participants in the idealized condition were trained exclusively on items that, according to a norming study, were relatively unambiguous. Participants in the actual condition were trained on a representative range of items. Despite being exclusively trained on easy items, idealized-condition participants were more accurate than those in the actual condition when tested on a range of item types. However, idealized participants experienced difficulties when test items were very dissimilar from training cases. The benefits of idealization, attributable to reducing noise arising from cognitive limitations in memory retrieval, suggest ways to improve real-world decision making. PMID:24955325

Improved Classification of Mammograms Following Idealized Training.

PubMed

Hornsby, Adam N; Love, Bradley C

2014-06-01

People often make decisions by stochastically retrieving a small set of relevant memories. This limited retrieval implies that human performance can be improved by training on idealized category distributions (Giguère & Love, 2013). Here, we evaluate whether the benefits of idealized training extend to categorization of real-world stimuli, namely classifying mammograms as normal or tumorous. Participants in the idealized condition were trained exclusively on items that, according to a norming study, were relatively unambiguous. Participants in the actual condition were trained on a representative range of items. Despite being exclusively trained on easy items, idealized-condition participants were more accurate than those in the actual condition when tested on a range of item types. However, idealized participants experienced difficulties when test items were very dissimilar from training cases. The benefits of idealization, attributable to reducing noise arising from cognitive limitations in memory retrieval, suggest ways to improve real-world decision making.

Solution-Phase Synthesis of Cesium Lead Halide Perovskite Nanowires.

PubMed

Zhang, Dandan; Eaton, Samuel W; Yu, Yi; Dou, Letian; Yang, Peidong

2015-07-29

Halide perovskites have attracted much attention over the past 5 years as a promising class of materials for optoelectronic applications. However, compared to hybrid organic-inorganic perovskites, the study of their pure inorganic counterparts, like cesium lead halides (CsPbX3), lags far behind. Here, a catalyst-free, solution-phase synthesis of CsPbX3 nanowires (NWs) is reported. These NWs are single-crystalline, with uniform growth direction, and crystallize in the orthorhombic phase. Both CsPbBr3 and CsPbI3 are photoluminescence active, with composition-dependent temperature and self-trapping behavior. These NWs with a well-defined morphology could serve as an ideal platform for the investigation of fundamental properties and the development of future applications in nanoscale optoelectronic devices based on all-inorganic perovskites.

An ideal free-kick

NASA Astrophysics Data System (ADS)

De Luca, R.; Faella, O.

2017-01-01

The kinematics of a free-kick is studied. As in projectile motion, the free-kick is ideal since we assume that a point-like ball moves in the absence of air resistance. We have experienced the fortunate conjuncture of a classical mechanics lecture taught right before an important football game. These types of sports events might trigger a great deal of attention from the classroom. The idealized problem is devised in such a way that students are eager to come to the end of the whole story.

Glass Transition Temperature of Saccharide Aqueous Solutions Estimated with the Free Volume/Percolation Model.

PubMed

Constantin, Julian Gelman; Schneider, Matthias; Corti, Horacio R

2016-06-09

The glass transition temperature of trehalose, sucrose, glucose, and fructose aqueous solutions has been predicted as a function of the water content by using the free volume/percolation model (FVPM). This model only requires the molar volume of water in the liquid and supercooled regimes, the molar volumes of the hypothetical pure liquid sugars at temperatures below their pure glass transition temperatures, and the molar volumes of the mixtures at the glass transition temperature. The model is simplified by assuming that the excess thermal expansion coefficient is negligible for saccharide-water mixtures, and this ideal FVPM becomes identical to the Gordon-Taylor model. It was found that the behavior of the water molar volume in trehalose-water mixtures at low temperatures can be obtained by assuming that the FVPM holds for this mixture. The temperature dependence of the water molar volume in the supercooled region of interest seems to be compatible with the recent hypothesis on the existence of two structure of liquid water, being the high density liquid water the state of water in the sugar solutions. The idealized FVPM describes the measured glass transition temperature of sucrose, glucose, and fructose aqueous solutions, with much better accuracy than both the Gordon-Taylor model based on an empirical kGT constant dependent on the saccharide glass transition temperature and the Couchman-Karasz model using experimental heat capacity changes of the components at the glass transition temperature. Thus, FVPM seems to be an excellent tool to predict the glass transition temperature of other aqueous saccharides and polyols solutions by resorting to volumetric information easily available.

Dynamics and stability of a 2D ideal vortex under external strain

NASA Astrophysics Data System (ADS)

Hurst, N. C.; Danielson, J. R.; Dubin, D. H. E.; Surko, C. M.

2017-11-01

The behavior of an initially axisymmetric 2D ideal vortex under an externally imposed strain flow is studied experimentally. The experiments are carried out using electron plasmas confined in a Penning-Malmberg trap; here, the dynamics of the plasma density transverse to the field are directly analogous to the dynamics of vorticity in a 2D ideal fluid. An external strain flow is applied using boundary conditions in a way that is consistent with 2D fluid dynamics. Data are compared to predictions from a theory assuming a piecewise constant elliptical vorticity distribution. Excellent agreement is found for quasi-flat profiles, whereas the dynamics of smooth profiles feature modified stability limits and inviscid damping of periodic elliptical distortions. This work supported by U.S. DOE Grants DE-SC0002451 and DE-SC0016532, and NSF Grant PHY-1414570.

Analytical pair correlations in ideal quantum gases: temperature-dependent bunching and antibunching.

PubMed

Bosse, J; Pathak, K N; Singh, G S

2011-10-01

The fluctuation-dissipation theorem together with the exact density response spectrum for ideal quantum gases has been utilized to yield a new expression for the static structure factor, which we use to derive exact analytical expressions for the temperature-dependent pair distribution function g(r) of the ideal gases. The plots of bosonic and fermionic g(r) display "Bose pile" and "Fermi hole" typically akin to bunching and antibunching as observed experimentally for ultracold atomic gases. The behavior of spin-scaled pair correlation for fermions is almost featureless, but bosons show a rich structure including long-range correlations near T(c). The coherent state at T=0 shows no correlation at all, just like single-mode lasers. The depicted decreasing trend in correlation with decrease in temperature for T

Ideal glass transitions in thin films: An energy landscape perspective

NASA Astrophysics Data System (ADS)

Truskett, Thomas M.; Ganesan, Venkat

2003-07-01

We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperature of thin films, suggesting the utility of landscape-based approaches for studying the behavior of confined fluids.

On controlling nonlinear dissipation in high order filter methods for ideal and non-ideal MHD

NASA Technical Reports Server (NTRS)

Yee, H. C.; Sjogreen, B.

2004-01-01

The newly developed adaptive numerical dissipation control in spatially high order filter schemes for the compressible Euler and Navier-Stokes equations has been recently extended to the ideal and non-ideal magnetohydrodynamics (MHD) equations. These filter schemes are applicable to complex unsteady MHD high-speed shock/shear/turbulence problems. They also provide a natural and efficient way for the minimization of Div(B) numerical error. The adaptive numerical dissipation mechanism consists of automatic detection of different flow features as distinct sensors to signal the appropriate type and amount of numerical dissipation/filter where needed and leave the rest of the region free from numerical dissipation contamination. The numerical dissipation considered consists of high order linear dissipation for the suppression of high frequency oscillation and the nonlinear dissipative portion of high-resolution shock-capturing methods for discontinuity capturing. The applicable nonlinear dissipative portion of high-resolution shock-capturing methods is very general. The objective of this paper is to investigate the performance of three commonly used types of nonlinear numerical dissipation for both the ideal and non-ideal MHD.

Reaction behaviors of decomposition of monocrotophos in aqueous solution by UV and UV/O processes.

PubMed

Ku, Y; Wang, W; Shen, Y S

2000-02-01

The decomposition of monocrotophos (cis-3-dimethoxyphosphinyloxy-N-methyl-crotonamide) in aqueous solution by UV and UV/O(3) processes was studied. The experiments were carried out under various solution pH values to investigate the decomposition efficiencies of the reactant and organic intermediates in order to determine the completeness of decomposition. The photolytic decomposition rate of monocrotophos was increased with increasing solution pH because the solution pH affects the distribution and light absorbance of monocrotophos species. The combination of O(3) with UV light apparently promoted the decomposition and mineralization of monocrotophos in aqueous solution. For the UV/O(3) process, the breakage of the >C=C< bond of monocrotophos by ozone molecules was found to occur first, followed by mineralization by hydroxyl radicals to generate CO(3)(2-), PO4(3-), and NO(3)(-) anions in sequence. The quasi-global kinetics based on a simplified consecutive-parallel reaction scheme was developed to describe the temporal behavior of monocrotophos decomposition in aqueous solution by the UV/O(3) process.

Nonlinear behavior of shells of revolution under cyclic loading

NASA Technical Reports Server (NTRS)

Levine, H. S.; Armen, H., Jr.; Winter, R.; Pifko, A.

1972-01-01

A large deflection elastic-plastic analysis is presented, applicable to orthotropic axisymmetric plates and shells of revolution subjected to monotonic and cyclic loading conditions. The analysis is based on the finite-element method. It employs a new higher order, fully compatible, doubly curved orthotropic shell-of-revolution element using cubic Hermitian expansions for both meridional and normal displacements. Both perfectly plastic and strain hardening behavior are considered. Strain hardening is incorporated through use of the Prager-Ziegler kinematic hardening theory, which predicts an ideal Bauschinger effect. Numerous sample problems involving monotonic and cyclic loading conditions are analyzed. The monotonic results are compared with other theoretical solutions.

Recharging Our Sense of Idealism: Concluding Thoughts

ERIC Educational Resources Information Center

D'Andrea, Michael; Dollarhide, Colette T.

2011-01-01

In this article, the authors aim to recharge one's sense of idealism. They argue that idealism is the Vitamin C that sustains one's commitment to implementing humanistic principles and social justice practices in the work of counselors and educators. The idealism that characterizes counselors and educators who are humanistic and social justice…

Insights into the rheological behaviors evolution of alginate dialdehyde crosslinked collagen solutions evaluated by numerical models.

PubMed

Zhu, Shichen; Yu, Xiaoyue; Xiong, Shanbai; Liu, Ru; Gu, Zhipeng; You, Juan; Yin, Tao; Hu, Yang

2017-09-01

The elaboration of the rheological behaviors of alginate dialdehyde (ADA) crosslinked collagen solutions, along with the quantitative analysis via numerical models contribute to the controllable design of ADA crosslinked solution system's fluid mechanics performance during manufacturing process for collagen biomaterials. In the present work, steady shear flow, dynamical viscoelasticity, creep-recovery, thixotropy tests were performed to characterize the rheological behaviors of the collagen solutions incorporating of ADA from the different aspects and fitted with corresponding numerical models. It was found that pseudoplastic properties of all samples enhanced with increasing amounts of ADA, which was confirmed by the parameters calculated from the Ostwald-de Waele model, Carreau and Cross model, for instance, the non-Newtonian index (n) decreased from 0.786 to 0.201 and a great increase by 280 times in value of viscosity index (K) was obtained from Ostwald-de Waele model. The forth-mode Leonov model was selected to fit all dynamic modulus-frequency curves due to its higher fitting precision (R 2 >0.99). It could be found that the values of correlation shear viscosity (η k ) increased and the values of relaxation time (θ k ) decreased with increasing ADA at the fixed k value, suggesting that the incorporation of ADA accelerated the transformation of the collagen solutions from liquid-like to gel-like state due to more formation of CN linkages between aldehyde groups and lysine residues. Also, the curves of creep and recovery phase of the native and crosslinked collagen solutions were simulated well using Burger model and a semi-empirical model, respectively. The ability to resist to deformation and elasticity strengthened for the samples with higher amounts of ADA, accompanied with the important fact that compliance value (J 50 ) decreased from 56.317Pa -1 to 2.135Pa -1 and the recovery percentage (R creep ) increased from 2.651% to 28.217%. Finally, it was found

Breastfeeding Solution Circle.

PubMed

Hilton, Sioned

2011-10-01

It is widely accepted and backed by research that breastfeeding is the number one feeding choice for babies, and direct from mothers' breasts is the ideal. However the early days can be challenging. Supporting mothers to succeed with their breastfeeding journey is a rewarding role and being able to advise and guide on overcoming the various hurdles is great. Keeping up to date on the research and advancements in breastfeeding support is vital and a general knowledge of the solutions to help will be of huge benefit to the mothers you are working with. This article examines the problems and some tried and tested solutions.

Socioeconomic status and parenting during adolescence in relation to ideal cardiovascular health in Black and White men.

PubMed

Matthews, Karen A; Boylan, Jennifer M; Jakubowski, Karen P; Cundiff, Jenny M; Lee, Laisze; Pardini, Dustin A; Jennings, J Richard

2017-07-01

American Heart Association (AHA) developed a new metric to evaluate ideal cardiovascular health based on optimal levels of 7 cardiovascular risk factors and health behaviors. We evaluated the relationships of parenting characteristics and academic achievement in adolescence in relation to ideal cardiovascular health in midlife men. We measured cardiovascular risk factors in 171 Black and 136 White men and their ideal cardiovascular health score was constructed based on AHA guidelines. When the participants were 13-16 years old, annual measures of parent-child communication, positive relationship, parental monitoring, family cohesion, boys' involvement in family activities, and academic achievement were recorded and averaged. Confirmatory factor analysis of adolescent parenting measures revealed a single Parenting Composite. Multiple linear regressions showed a significant Race by Parenting Composite interaction term, β = -.19, p = .03; better parenting was significantly related to more ideal cardiovascular health in Blacks only, β = -.23, p = .004, which remained after adjustments for adolescent and adult socioeconomic status (SES). Academic achievement was related to ideal cardiovascular health, β = -.13, but was no longer significant after controls for adult SES. Adult SES was a strong correlate of ideal cardiovascular health in Black and White men. Black men exposed to positive parenting during adolescence had more ideal cardiovascular health based on AHA guidelines. Improving academic achievement in adolescence may indirectly benefit adult cardiovascular health through improving adult SES. This is the first study of adolescent family predictors of the extent of ideal cardiovascular health. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Dynamical properties of water-methanol solutions

NASA Astrophysics Data System (ADS)

Mallamace, Francesco; Corsaro, Carmelo; Mallamace, Domenico; Vasi, Cirino; Vasi, Sebastiano; Stanley, H. Eugene

2016-02-01

We study the relaxation times tα in the water-methanol system. We examine new data and data from the literature in the large temperature range 163 < T < 335 K obtained using different experimental techniques and focus on how tα affects the hydrogen bond structure of the system and the hydrophobicity of the alcohol methyl group. We examine the relaxation times at a fixed temperature as a function of the water molar fraction XW and observe two opposite behaviors in their curvature when the system moves from high to low T regimes. This behavior differs from that of an ideal solution in that it has excess values located at different molar fractions (XW = 0.5 for high T and 0.75 in the deep supercooled regime). We analyze the data and find that above a crossover temperature T ˜ 223 K, hydrophobicity plays a significant role and below it the water tetrahedral network dominates. This temperature is coincident with the fragile-to-strong dynamical crossover observed in confined water and supports the liquid-liquid phase transition hypothesis. At the same time, the reported data suggest that this crossover temperature (identified as the Widom line temperature) also depends on the alcohol concentration.

Magnetogasdynamic spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes

NASA Astrophysics Data System (ADS)

Nath, G.; Vishwakarma, J. P.

2016-11-01

Similarity solutions are obtained for the flow behind a spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes, in the presence of a spatially decreasing azimuthal magnetic field. The shock wave is driven by a piston moving with time according to power law. The radiation is considered to be of the diffusion type for an optically thick grey gas model and the heat conduction is expressed in terms of Fourier's law for heat conduction. Similarity solutions exist only when the surrounding medium is of constant density. The gas is assumed to have infinite electrical conductivity and to obey a simplified van der Waals equation of state. It is shown that an increase of the gravitational parameter or the Alfven-Mach number or the parameter of the non-idealness of the gas decreases the compressibility of the gas in the flow-field behind the shock, and hence there is a decrease in the shock strength. The pressure and density vanish at the inner surface (piston) and hence a vacuum is formed at the center of symmetry. The shock waves in conducting non-ideal gas under gravitational field with conductive and radiative heat fluxes can be important for description of shocks in supernova explosions, in the study of a flare produced shock in the solar wind, central part of star burst galaxies, nuclear explosion etc. The solutions obtained can be used to interpret measurements carried out by space craft in the solar wind and in neighborhood of the Earth's magnetosphere.

Genetic and environmental influences on thin-ideal internalization.

PubMed

Suisman, Jessica L; O'Connor, Shannon M; Sperry, Steffanie; Thompson, J Kevin; Keel, Pamela K; Burt, S Alexandra; Neale, Michael; Boker, Steven; Sisk, Cheryl; Klump, Kelly L

2012-12-01

Current research on the etiology of thin-ideal internalization focuses on psychosocial influences (e.g., media exposure). The possibility that genetic influences also account for variance in thin-ideal internalization has never been directly examined. This study used a twin design to estimate genetic effects on thin-ideal internalization and examine if environmental influences are primarily shared or nonshared in origin. Participants were 343 postpubertal female twins (ages: 12-22 years; M = 17.61) from the Michigan State University Twin Registry. Thin-ideal internalization was assessed using the Sociocultural Attitudes toward Appearance Questionnaire-3. Twin modeling suggested significant additive genetic and nonshared environmental influences on thin-ideal internalization. Shared environmental influences were small and non-significant. Although prior research focused on psychosocial factors, genetic influences on thin-ideal internalization were significant and moderate in magnitude. Research is needed to investigate possible interplay between genetic and nonshared environmental factors in the development of thin-ideal internalization. Copyright © 2012 Wiley Periodicals, Inc.

Effect of Aging Temperature on Corrosion Behavior of Sintered 17-4 PH Stainless Steel in Dilute Sulfuric Acid Solution

NASA Astrophysics Data System (ADS)

Szewczyk-Nykiel, Aneta; Kazior, Jan

2017-07-01

The general corrosion behavior of sintered 17-4 PH stainless steel processed under different processing conditions in dilute sulfuric acid solution at 25 °C was studied by open-circuit potential measurement and potentiodynamic polarization technique. The corrosion resistance was evaluated based on electrochemical parameters, such as polarization resistance, corrosion potential, corrosion current density as well as corrosion rate. The results showed that the precipitation-hardening treatment could significantly improve the corrosion resistance of the sintered 17-4 PH stainless steel in studied environment. As far as the influence of aging temperature on corrosion behavior of the sintered 17-4 PH stainless steel is concerned, polarization resistance and corrosion rate are reduced with increasing aging temperature from 480 up to 500 °C regardless of the temperature of solution treatment. It can be concluded that the highest corrosion resistance in 0.5 M H2SO4 solution exhibits 17-4 PH after solution treatment at 1040 °C followed by aging at 480 °C.

Glass transition behavior of the vitrification solutions containing propanediol, dimethyl sulfoxide and polyvinyl alcohol.

PubMed

Wang, Hai-Yan; Lu, Shu-Shen; Lun, Zhao-Rong

2009-02-01

Knowledge of the glass transition behavior of vitrification solutions is important for research and planning of the cryopreservation of biological materials by vitrification. This brief communication shows the analysis for the glass transition and glass stability of the multi-component vitrification solutions containing propanediol (PE), dimethyl sulfoxide (Me2SO) and polyvinyl alcohol (PVA) by using differential scanning calorimetry (DSC) during the cooling and subsequent warming between 25 and -150 degrees C. The glass formation of the solutions was enhanced by introduction of PVA. Partial glass formed during cooling and the fractions of free water in the partial glass matrix increased with the increasing of PVA concentration, which caused slight decline of glass transition temperature, T(g). Exothermic peaks of devitrification were delayed and broadened, which may result from the inhibition of ice nucleation or recrystallization of PVA.

Temporal behavior of a solute cloud in a fractal heterogeneous porous medium at different scales

NASA Astrophysics Data System (ADS)

Ross, Katharina; Attinger, Sabine

2010-05-01

Water pollution is still a very real problem and the need for efficient models for flow and solute transport in heterogeneous porous or fractured media is evident. In our study we focus on solute transport in heterogeneous fractured media. In heterogeneous fractured media the shape of the pores and fractures in the subsurface might be modeled as a fractal network or a heterogeneous structure with infinite correlation length. To derive explicit results for larger scale or effective transport parameters in such structures is the aim of this work. To describe flow and transport we investigate the temporal behavior of transport coefficients of solute movement through a spatially heterogeneous medium. It is necessary to distinguish between two fundamentally different quantities characterizing the solute dispersion: The effective dispersion coefficient Deff(t) represents the physical (observable) dispersion in one given realization of the medium. It is conceptually different from the mathematically simpler ensemble dispersion coefficient Dens(t) which characterizes the (abstract) dispersion with respect to the set of all possible realizations of the medium. In the framework of a stochastic approach DENTZ ET AL. (2000 I[2] & II[3]) derive explicit expressions for the temporal behavior of the center-of-mass velocity and the dispersion of the concentration distribution, using a second order perturbation expansion. In their model the authors assume a finite correlation length of the heterogeneities and use a GAUSSIAN correlation function. In a first step, we model the fractured medium as a heterogeneous porous medium with infinite correlation length and neglect single fractures. ZHAN & WHEATCRAFT (1996[4]) analyze the macrodispersivity tensor in fractal porous media using a non-integer exponent which consists of the HURST coefficient and the fractal dimension D. To avoid this non-integer exponent for numerical reasons we extend the study of DENTZ ET AL. (2000 I[2] & II[3

Apatite-Melt Partitioning at 1 Bar: An Assessment of Apatite-Melt Exchange Equilibria Resulting from Non-Ideal Mixing of F and Cl in Apatite

NASA Technical Reports Server (NTRS)

McCubbin, F. M.; Ustunisik, G.; Vander Kaaden, K. E.

2016-01-01

The mineral apatite [Ca5(PO4)3(F,Cl,OH)] is present in a wide range of planetary materials. Due to the presence of volatiles within its crystal structure (X-site), many recent studies have attempted to use apatite to constrain the volatile contents of planetary magmas and mantle sources. In order to use the volatile contents of apatite to precisely determine the abundances of volatiles in coexisting silicate melt or fluids, thermodynamic models for the apatite solid solution and for the apatite components in multi-component silicate melts and fluids are required. Although some thermodynamic models for apatite have been developed, they are incomplete. Furthermore, no mixing model is available for all of the apatite components in silicate melts or fluids, especially for F and Cl components. Several experimental studies have investigated the apatite-melt and apatite-fluid partitioning behavior of F, Cl, and OH in terrestrial and planetary systems, which have determined that apatite-melt partitioning of volatiles are best described as exchange equilibria similar to Fe-Mg partitioning between olivine and silicate melt. However, McCubbin et al. recently reported that the exchange coefficients may vary in portions of apatite compositional space where F, Cl, and OH do not mix ideally in apatite. In particular, solution calorimetry data of apatite compositions along the F-Cl join exhibit substantial excess enthalpies of mixing. In the present study, we conducted apatite-melt partitioning experiments in evacuated, sealed silica-glass tubes at approximately 1 bar and 950-1050 degrees Centigrade on a synthetic Martian basalt composition equivalent to the basaltic shergottite Queen Alexandria Range (QUE) 94201. These experiments were conducted dry, at low pressure, to assess the effects of temperature and apatite composition on the partitioning behavior of F and Cl between apatite and basaltic melt along the F-Cl apatite binary join, where there is non-ideal mixing of F and Cl

Ideal and resistive plasma resistive wall modes and control: linear and nonlinear

NASA Astrophysics Data System (ADS)

Finn, J. M.; Chacon, L.

2004-11-01

Our recent work* on control of linear and nonlinear resistive wall modes (RWM) showed that if there is an ideal plasma mode and a resistive plasma mode, and if the beta limit for the latter is lower (as is typical), then nonlinear resistive wall modes behave basically as nonlinear tearing-like modes locked to the wall. We investigate here the effect of plasma rotation sufficient to stabilize the resistive-plasma RWM but not the ideal plasma RWM. We also review results** showing the effect of normal and poloidal magnetic field sensing, and describe a simple model which is amenable to analytic solution, and which makes previously obtained simulation results transparent. *J. Finn and L. Chacon, 'Control of linear and nonlinear resistive wall modes', Phys. Plas 11, 1866 (2004). **J. Finn, 'Control of resistive wall modes in a cylindrical tokamak with radial and poloidal magnetic field sensors', to appear in Phys. Plasmas, 2004.

Noether symmetries and stability of ideal gas solutions in Galileon cosmology

NASA Astrophysics Data System (ADS)

Dimakis, N.; Giacomini, Alex; Jamal, Sameerah; Leon, Genly; Paliathanasis, Andronikos

2017-03-01

A class of generalized Galileon cosmological models, which can be described by a pointlike Lagrangian, is considered in order to utilize Noether's theorem to determine conservation laws for the field equations. In the Friedmann-Lemaître-Robertson-Walker universe, the existence of a nontrivial conservation law indicates the integrability of the field equations. Because of the complexity of the latter, we apply the differential invariants approach in order to construct special power-law solutions and study their stability.

Corrosion fatigue crack growth behavior of titanium alloys in aqueous solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shipilov, S.A.

1998-01-01

The corrosion fatigue crack growth (FCG) behavior, the effect of applied potential on corrosion FCG rates, and the fracture surfaces of VT20 (near-{alpha}) and TS6 (near-{beta}) titanium alloys were studied. Environments were aqueous solutions of sodium chloride (NaCl), sodium hydroxide (NaOH), potassium hydroxide (KOH), ferric chloride (FeCl{sub 3}), and chromic acid (H{sub 2}CrO{sub 4}) with and without NaCl. Depending upon solution composition, corrosion FCG rates were found to be higher or lower than those in air. Cathodic polarization retarded the corrosion FCG, while anodic polarization accelerated insignificantly or almost did not influence it in most of the solutions investigated. However,more » cathodic polarization accelerated corrosion FCG in 0.6 M FeCl{sub 3} and 0.5 M to 2 M H{sub 2}CrO{sub 4} + 0.01 M to 0.1 M NaCl solutions by a dozen times when the maximum stress intensity (K{sub max}) exceeded certain critical values. When K{sub max} was lower than the critical values, the same cathodic polarization (with all other /conditions being equal) retarded corrosion FCG. Results suggested the accelerated crack growth at cathodic potentials resulted from hydrogen-induced cracking (HIC). Therefore, critical values of K{sub max}, as well as the stress intensity range ({Delta}K) were regarded as corresponding to the beginning of corrosion FCG according to a HIC mechanism and designated as K{sub HIC} and {Delta}K{sub HIC}.« less

Yield Behavior of Solution Treated and Aged Ti-6Al-4V

NASA Technical Reports Server (NTRS)

Ring, Andrew J.; Baker, Eric H.; Salem, Jonathan A.; Thesken, John C.

2014-01-01

Post yield uniaxial tension-compression tests were run on a solution treated and aged (STA), titanium 6-percent aluminum 4-percent vanadium (Ti-6Al-4V) alloy to determine the yield behavior on load reversal. The material exhibits plastic behavior almost immediately on load reversal implying a strong Bauschinger effect. The resultant stress-strain data was compared to a 1D mechanics model and a finite element model used to design a composite overwrapped pressure vessel (COPV). Although the models and experimental data compare well for the initial loading and unloading in the tensile regime, agreement is lost in the compressive regime due to the Bauschinger effect and the assumption of perfect plasticity. The test data presented here are being used to develop more accurate cyclic hardening constitutive models for future finite element design analysis of COPVs.

Global Classical Solutions for MHD System

NASA Astrophysics Data System (ADS)

Casella, E.; Secchi, P.; Trebeschi, P.

In this paper we study the equations of magneto-hydrodynamics for a 2D incompressible ideal fluid in the exterior domain and in the half-plane. We prove the existence of a global classical solution in Hölder spaces, by applying Shauder fixed point theorem.

The Statistical Mechanics of Ideal Homogeneous Turbulence

NASA Technical Reports Server (NTRS)

Shebalin, John V.

2002-01-01

Plasmas, such as those found in the space environment or in plasma confinement devices, are often modeled as electrically conducting fluids. When fluids and plasmas are energetically stirred, regions of highly nonlinear, chaotic behavior known as turbulence arise. Understanding the fundamental nature of turbulence is a long-standing theoretical challenge. The present work describes a statistical theory concerning a certain class of nonlinear, finite dimensional, dynamical models of turbulence. These models arise when the partial differential equations describing incompressible, ideal (i.e., nondissipative) homogeneous fluid and magnetofluid (i.e., plasma) turbulence are Fourier transformed into a very large set of ordinary differential equations. These equations define a divergenceless flow in a high-dimensional phase space, which allows for the existence of a Liouville theorem, guaranteeing a distribution function based on constants of the motion (integral invariants). The novelty of these particular dynamical systems is that there are integral invariants other than the energy, and that some of these invariants behave like pseudoscalars under two of the discrete symmetry transformations of physics, parity, and charge conjugation. In this work the 'rugged invariants' of ideal homogeneous turbulence are shown to be the only significant scalar and pseudoscalar invariants. The discovery that pseudoscalar invariants cause symmetries of the original equations to be dynamically broken and induce a nonergodic structure on the associated phase space is the primary result presented here. Applicability of this result to dissipative turbulence is also discussed.

Ideal MHD stability and characteristics of edge localized modes on CFETR

NASA Astrophysics Data System (ADS)

Li, Ze-Yu; Chan, V. S.; Zhu, Yi-Ren; Jian, Xiang; Chen, Jia-Le; Cheng, Shi-Kui; Zhu, Ping; Xu, Xue-Qiao; Xia, Tian-Yang; Li, Guo-Qiang; Lao, L. L.; Snyder, P. B.; Wang, Xiao-Gang; the CFETR Physics Team

2018-01-01

Investigation on the equilibrium operation regime, its ideal magnetohydrodynamics (MHD) stability and edge localized modes (ELM) characteristics is performed for the China Fusion Engineering Test Reactor (CFETR). The CFETR operation regime study starts with a baseline scenario (R  =  5.7 m, B T  =  5 T) derived from multi-code integrated modeling, with key parameters {{β }N},{{β }T},{{β }p} varied to build a systematic database. These parameters, under profile and pedestal constraints, provide the foundation for the engineering design. The long wavelength low-n global ideal MHD stability of the CFETR baseline scenario, including the wall stabilization effect, is evaluated by GATO. It is found that the low-n core modes are stable with a wall at r/a  =  1.2. An investigation of intermediate wavelength ideal MHD modes (peeling ballooning modes) is also carried out by multi-code benchmarking, including GATO, ELITE, BOUT++ and NIMROD. A good agreement is achieved in predicting edge-localized instabilities. Nonlinear behavior of ELMs for the baseline scenario is simulated using BOUT++. A mix of grassy and type I ELMs is identified. When the size and magnetic field of CFETR are increased (R  =  6.6 m, B T  =  6 T), collisionality correspondingly increases and the instability is expected to shift to grassy ELMs.

Rheological behavior of FM-9 solutions and correlation with flammability test results and interpretations. [fuel thickening additive

NASA Technical Reports Server (NTRS)

Peng, S. T. J.; Landel, R. F.

1983-01-01

The rheological behavior of progressively shear thickening FM-9 solutions, a time-dependent shear thickening material with characteristics of threshold behavior, is investigated as part of a study of the rheological properties of antimisting jet fuel. Flammability test results and test configurations from various sources are evaluated. A correlation is obtained between the rheological behavior and the flammability tests such that, for a given system, such as a fixed solvent system and the FM-9 polymer system, the flammability criterion can be applied to a wide range of concentrations and temperatures.

Simple, explicitly time-dependent, and regular solutions of the linearized vacuum Einstein equations in Bondi-Sachs coordinates

NASA Astrophysics Data System (ADS)

Mädler, Thomas

2013-05-01

Perturbations of the linearized vacuum Einstein equations in the Bondi-Sachs formulation of general relativity can be derived from a single master function with spin weight two, which is related to the Weyl scalar Ψ0, and which is determined by a simple wave equation. By utilizing a standard spin representation of tensors on a sphere and two different approaches to solve the master equation, we are able to determine two simple and explicitly time-dependent solutions. Both solutions, of which one is asymptotically flat, comply with the regularity conditions at the vertex of the null cone. For the asymptotically flat solution we calculate the corresponding linearized perturbations, describing all multipoles of spin-2 waves that propagate on a Minkowskian background spacetime. We also analyze the asymptotic behavior of this solution at null infinity using a Penrose compactification and calculate the Weyl scalar Ψ4. Because of its simplicity, the asymptotically flat solution presented here is ideally suited for test bed calculations in the Bondi-Sachs formulation of numerical relativity. It may be considered as a sibling of the Bergmann-Sachs or Teukolsky-Rinne solutions, on spacelike hypersurfaces, for a metric adapted to null hypersurfaces.

Effect of compositional heterogeneity on dissolution of non-ideal LNAPL mixtures

NASA Astrophysics Data System (ADS)

Vasudevan, M.; Johnston, C. D.; Bastow, T. P.; Lekmine, G.; Rayner, J. L.; Nambi, I. M.; Suresh Kumar, G.; Ravi Krishna, R.; Davis, G. B.

2016-11-01

The extent of dissolution of petroleum hydrocarbon fuels into groundwater depends greatly on fuel composition. Petroleum fuels can consist of thousands of compounds creating different interactions within the non-aqueous phase liquid (NAPL), thereby affecting the relative dissolution of the components and hence a groundwater plume's composition over long periods. Laboratory experiments were conducted to study the variability in the effective solubilities and activity coefficients for common constituents of gasoline fuels (benzene, toluene, p-xylene and 1,2,4-trimethylbenzene) (BTX) in matrices with an extreme range of molar volumes and chemical affinities. Four synthetic mixtures were investigated comprising BTX with the bulk of the NAPL mixtures made up of either, ethylbenzene (an aromatic like BTX with similar molar volume); 1,3,5-trimethylbenzene (an aromatic with a greater molar volume); n-hexane (an aliphatic with a low molar volume); and n-decane (an aliphatic with a high molar volume). Equilibrium solubility values for the constituents were under-predicted by Raoult's law by up to 30% (higher experimental concentrations) for the mixture with n-hexane as a filler and over-predicted by up to 12% (lower experimental concentrations) for the aromatic mixtures with ethylbenzene and 1,3,5-trimethylbenzene as fillers. Application of PP-LFER (poly-parameter linear free energy relationship) model for non-ideal mixtures also resulted in poor correlation between experimentally measured and predicted concentrations, indicating that differences in chemical affinities can be the major cause of deviation from ideal behavior. Synthetic mixtures were compared with the dissolution behavior of fresh and naturally weathered unleaded gasoline. The presence of lighter aliphatic components in the gasoline had a profound effect on estimating effective solubility due to chemical affinity differences (estimated at 0.0055 per percentage increase in the molar proportion of aliphatic) as

Corrosion Behavior of Cu40Zn in Sulfide-Polluted 3.5% NaCl Solution

NASA Astrophysics Data System (ADS)

Song, Q. N.; Xu, N.; Bao, Y. F.; Jiang, Y. F.; Gu, W.; Yang, Z.; Zheng, Y. G.; Qiao, Y. X.

2017-10-01

The corrosion behavior of a duplex-phase brass Cu40Zn in clean and sulfide-polluted 3.5% NaCl solutions was investigated by conducting electrochemical and gravimetric measurements. The corrosion product films were analyzed by scanning electron microscopy, energy-dispersive spectroscopy and x-ray diffraction. The presence of sulfide shifted the corrosion potential of Cu40Zn toward a more negative value by 100 mV and increased the mass loss rate by a factor of 1.257 compared with the result in the clean solution. The corrosion product film in the clean solution was thin and compact; it mainly consisted of oxides, such as ZnO and Cu2O. By contrast, the film in the sulfide-polluted solution was thick and porous. It mainly contained sulfides and zinc hydroxide chloride (i.e., Zn5(OH)8Cl2·H2O). The presence of sulfide ions accelerated the corrosion damage of Cu40Zn by hindering the formation of protective oxides and promoting the formation of a defective film which consisted of sulfides and hydroxide chlorides.

The moderating effect of gender on ideal-weight goals and exercise dependence symptoms.

PubMed

Cook, Brian; Hausenblas, Heather; Rossi, James

2013-03-01

Background and aims Exercise dependence is implicated in the development of eating disorders and muscle dysmorphic disorder. Although conceptually these disorders represent similar pathologies they largely affect different genders and result in opposite body composition, appearance, and ideal-weight goals (i.e., to gain or lose/maintain weight). Therefore, understanding individuals' ideal-weight goals related to engaging in exercise while simultaneously examining gender differences in exercise dependence symptoms may help to identify those whom may be most at-risk for eating disorders and muscle dysmorphic disorder. The purpose of our study was to examine the moderating effect of gender for exercise dependence symptoms in relation to weight gain, loss, or maintenance goals. Methods Self-reported exercise behavior and exercise dependence symptoms (i.e., Exercise Dependence Scale) were assessed in 513 undergraduate students. Results Our analysis revealed a moderating effect for gender on ideal-weight goals and a gender difference in exercise dependence symptoms. Specifically, men who were dissatisfied with their current weight reported more exercise dependence symptoms than women. Conclusions These results support a growing body of research and extend our understanding of the relationships among exercise dependence and gender specific body-focused psychiatric disorders.

Dynamical Approach Study of Spurious Steady-State Numerical Solutions of Nonlinear Differential Equations. 2; Global Asymptotic Behavior of Time Discretizations; 2. Global Asymptotic Behavior of time Discretizations

NASA Technical Reports Server (NTRS)

Yee, H. C.; Sweby, P. K.

1995-01-01

The global asymptotic nonlinear behavior of 1 1 explicit and implicit time discretizations for four 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODES) is analyzed. The objectives are to gain a basic understanding of the difference in the dynamics of numerics between the scalars and systems of nonlinear autonomous ODEs and to set a baseline global asymptotic solution behavior of these schemes for practical computations in computational fluid dynamics. We show how 'numerical' basins of attraction can complement the bifurcation diagrams in gaining more detailed global asymptotic behavior of time discretizations for nonlinear differential equations (DEs). We show how in the presence of spurious asymptotes the basins of the true stable steady states can be segmented by the basins of the spurious stable and unstable asymptotes. One major consequence of this phenomenon which is not commonly known is that this spurious behavior can result in a dramatic distortion and, in most cases, a dramatic shrinkage and segmentation of the basin of attraction of the true solution for finite time steps. Such distortion, shrinkage and segmentation of the numerical basins of attraction will occur regardless of the stability of the spurious asymptotes, and will occur for unconditionally stable implicit linear multistep methods. In other words, for the same (common) steady-state solution the associated basin of attraction of the DE might be very different from the discretized counterparts and the numerical basin of attraction can be very different from numerical method to numerical method. The results can be used as an explanation for possible causes of error, and slow convergence and nonconvergence of steady-state numerical solutions when using the time-dependent approach for nonlinear hyperbolic or parabolic PDES.

Corrosion behavior of heat-treated intermetallic titanium-nickel in hydrochloric acid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Starosvetsky, D.; Khaselev, O.; Yahalom, J.

1998-07-01

Samples of 45% Ti-55% Ni alloy (Ti-Ni) were heat-treated in air at 450 C, and their anodic behavior in 0.3 M, 1 M, 2 M, and 4 M hydrochloric acid (HCl) solutions was studied. In 0.3 M HCl, heat-treated Ti-Ni was passive, and very low anodic currents were observed. In 1 M and 2 M HCl, heat-treated Ti-Ni was dissolved actively, while heat-treated and surface-ground Ti-Ni became passive. The effect was explained by selective oxidation of Ti-Ni and formation of a layered structure on its surface with discontinuous titanium oxide and a nickel-enriched zone underneath. The latter was dissolved inmore » the HCl solutions, thus accelerating failure of the Ti-Ni samples. In 4 M HCl, heat-treated and heat-treated/ground samples were dissolved readily.« less

A class of nonideal solutions. 1: Definition and properties

NASA Technical Reports Server (NTRS)

Zeleznik, F. J.

1983-01-01

A class of nonideal solutions is defined by constructing a function to represent the composition dependence of thermodynamic properties for members of the class, and some properties of these solutions are studied. The constructed function has several useful features: (1) its parameters occur linearly; (2) it contains a logarithmic singularity in the dilute solution region and contains ideal solutions and regular solutions as special cases; and (3) it is applicable to N-ary systems and reduces to M-ary systems (M or = N) in a form-invariant manner.

Thermodynamic Mixing Behavior Of F-OH Apatite Crystalline Solutions

NASA Astrophysics Data System (ADS)

Hovis, G. L.

2011-12-01

intermediate series members, as doubled peaks merged into single diffraction maxima, the latter changing position systematically with bulk composition. All of the resulting F-OH apatite series members have hexagonal symmetry. The "a" unit-cell dimension behaves linearly with composition, and "c" is nearly constant across the series. Unit-cell volume also is linear with F:OH ratio, thus behaving in a thermodynamically ideal manner. Solution calorimetric experiments have been conducted in 20.0 wt % HCl at 50 °C on all series members. Enthalpies of F-OH mixing are nonexistent at F-rich compositions but have small negative values toward the hydroxylapatite end member. There is no enthalpy barrier, therefore, to complete F-OH mixing across the series, indicated as well by the ease of chemical homogenization for intermediate F:OH series members. In addition to the synthetic specimens described above, natural samples of hydroxylapatite, fluorapatite, and chlorapatite have been obtained for study from the U.S. National Museum of Natural History, as well as the American Museum of Natural History (our sincere appreciation to both museums for providing samples). Solution calorimetric results for these samples will be compared with data for the synthetic OH, F, and Cl apatite analogs noted above.

Positron kinetics in an idealized PET environment

PubMed Central

Robson, R. E.; Brunger, M. J.; Buckman, S. J.; Garcia, G.; Petrović, Z. Lj.; White, R. D.

2015-01-01

The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range - a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the ‘gas-phase’ assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations. PMID:26246002

Rheological Behavior of Xanthan Gum Solution Related to Shear Thinning Fluid Delivery for Subsurface Remediation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Lirong; Oostrom, Martinus; Truex, Michael J.

Xanthan gum, a biopolymer, forms shear thinning fluids which can be used as delivery media to improve the distribution of remedial amendments injected into heterogeneous subsurface environments. The rheological behavior of the shear thinning solution needs to be known to develop an appropriate design for field injection. In this study, the rheological properties of xanthan gum solutions were obtained under various chemical and environmental conditions relevant to delivery of remedial amendments to groundwater. Higher xanthan concentration raised the absolute solution viscosity and increased the degree of shear thinning. Addition of remedial amendments (e.g., phosphate, sodium lactate, ethyl lactate) caused themore » dynamic viscosity of xanthan gum to decrease, but the solutions maintained shear-thinning properties. Use of simple salt (e.g. Na+, Ca2+) to increase the solution ionic strength also decreased the dynamic viscosity of xanthan and the degree of shear thinning, although the effect is a function of xanthan gum concentration and diminished as the xanthan gum concentration was increased. At high xanthan concentration, addition of salt to the solution increased dynamic viscosity. In the absence of sediments, xanthan gum solutions maintain their viscosity properties for months. However, xanthan gum solutions were shown to lose dynamic viscosity over a period of days to weeks when contacted with saturated site sediment. Loss of viscosity is attributed to physical and biodegradation processes.« less

Electrochemical research on corrosion behavior of A3 steel in compound sodium molybadate and organic inhibitor solution

NASA Astrophysics Data System (ADS)

Sun, C. X.; Chen, Y. M.; Xu, H. W.; Zhang, M.; Chen, M.; Xue, M.; Wu, J. Y.; Huang, C. S.

2015-07-01

The electrochemical corrosion behavior of A3 in compound sodium molybdate and organic inhibitor solution was tested by the electrochemical workstation method. The concentration of the compound inhibitor set to range 250 mg/L to 3000 mg/L. The polarization curve results of A3 in different concentration inhibitor solutions show that the inhibitor markedly represses the anodic processes. The EIS has two time constant. The extreme concentration is 1500 mg/L.

Broken Ergodicity in Ideal, Homogeneous, Incompressible Turbulence

NASA Technical Reports Server (NTRS)

Morin, Lee; Shebalin, John; Fu, Terry; Nguyen, Phu; Shum, Victor

2010-01-01

We discuss the statistical mechanics of numerical models of ideal homogeneous, incompressible turbulence and their relevance for dissipative fluids and magnetofluids. These numerical models are based on Fourier series and the relevant statistical theory predicts that Fourier coefficients of fluid velocity and magnetic fields (if present) are zero-mean random variables. However, numerical simulations clearly show that certain coefficients have a non-zero mean value that can be very large compared to the associated standard deviation. We explain this phenomena in terms of broken ergodicity', which is defined to occur when dynamical behavior does not match ensemble predictions on very long time-scales. We review the theoretical basis of broken ergodicity, apply it to 2-D and 3-D fluid and magnetohydrodynamic simulations of homogeneous turbulence, and show new results from simulations using GPU (graphical processing unit) computers.

Drive for muscularity and social physique anxiety mediate the perceived ideal physique muscle dysmorphia relationship.

PubMed

Thomas, Adam; Tod, David A; Edwards, Christian J; McGuigan, Michael R

2014-12-01

This study examined the mediating role of drive for muscularity and social physique anxiety (SPA) in the perceived muscular male ideal physique and muscle dysmorphia relationship in weight training men. Men (N = 146, mean ± SD; age, 22.8 ± 5.0 years; weight, 82.0 ± 11.1 kg; height, 1.80 ± 0.07 m; body mass index, 25.1 ± 3.0) who participated in weight training completed validated questionnaires measuring drive for muscularity, SPA, perceived muscular male ideal physique, global muscle dysmorphia, and several characteristics of muscle dysmorphia (exercise dependence, diet manipulation, concerns about size/symmetry, physique protection behavior, and supplementation). Perceived ideal physique was an independent predictor of muscle dysmorphia measures except physique protection (coefficients = 0.113-0.149, p ≤ 0.05). Perceived ideal physique also predicted muscle dysmorphia characteristics (except physique protection and diet) through the indirect drive for muscularity pathway (coefficients = 0.055-0.116, p ≤ 0.05). Perceived ideal physique also predicted size/symmetry concerns and physique protection through the indirect drive for muscularity and SPA pathway (coefficients = 0.080-0.025, p ≤ 0.05). These results extend current research by providing insights into the way correlates of muscle dysmorphia interact to predict the condition. The results also highlight signs (e.g., anxiety about muscularity) that strength and conditioning coaches can use to identify at-risk people who may benefit from being referred for psychological assistance.

Analytical Solutions, Moments, and Their Asymptotic Behaviors for the Time-Space Fractional Cable Equation

NASA Astrophysics Data System (ADS)

Li, Can; Deng, Wei-Hua

2014-07-01

Following the fractional cable equation established in the letter [B.I. Henry, T.A.M. Langlands, and S.L. Wearne, Phys. Rev. Lett. 100 (2008) 128103], we present the time-space fractional cable equation which describes the anomalous transport of electrodiffusion in nerve cells. The derivation is based on the generalized fractional Ohm's law; and the temporal memory effects and spatial-nonlocality are involved in the time-space fractional model. With the help of integral transform method we derive the analytical solutions expressed by the Green's function; the corresponding fractional moments are calculated; and their asymptotic behaviors are discussed. In addition, the explicit solutions of the considered model with two different external current injections are also presented.

Visualizing phase transition behavior of dilute stimuli responsive polymer solutions via Mueller matrix polarimetry.

PubMed

Narayanan, Amal; Chandel, Shubham; Ghosh, Nirmalya; De, Priyadarsi

2015-09-15

Probing volume phase transition behavior of superdiluted polymer solutions both micro- and macroscopically still persists as an outstanding challenge. In this regard, we have explored 4 × 4 spectral Mueller matrix measurement and its inverse analysis for excavating the microarchitectural facts about stimuli responsiveness of "smart" polymers. Phase separation behavior of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and pH responsive poly(N,N-(dimethylamino)ethyl methacrylate) (PDMAEMA) and their copolymers were analyzed in terms of Mueller matrix derived polarization parameters, namely, depolarization (Δ), diattenuation (d), and linear retardance (δ). The Δ, d, and δ parameters provided useful information on both macro- and microstructural alterations during the phase separation. Additionally, the two step action ((i) breakage of polymer-water hydrogen bonding and (ii) polymer-polymer aggregation) at the molecular microenvironment during the cloud point generation was successfully probed via these parameters. It is demonstrated that, in comparison to the present techniques available for assessing the hydrophobic-hydrophilic switch over of simple stimuli-responsive polymers, Mueller matrix polarimetry offers an important advantage requiring a few hundred times dilute polymer solution (0.01 mg/mL, 1.1-1.4 μM) at a low-volume format.

Predicting Film Genres with Implicit Ideals

PubMed Central

Olney, Andrew McGregor

2013-01-01

We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

Predicting film genres with implicit ideals.

PubMed

Olney, Andrew McGregor

2012-01-01

We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories.

New generalized Noh solutions for HEDP hydrocode verification

NASA Astrophysics Data System (ADS)

Velikovich, A. L.; Giuliani, J. L.; Zalesak, S. T.; Tangri, V.

2017-10-01

The classic Noh solution describing stagnation of a cold ideal gas in a strong accretion shock wave has been the workhorse of compressible hydrocode verification for over three decades. We describe a number of its generalizations available for HEDP code verification. First, for an ideal gas, we have obtained self-similar solutions that describe adiabatic convergence either of a finite-pressure gas into an empty cavity or of a finite-amplitude sound wave into a uniform resting gas surrounding the center or axis of symmetry. At the moment of collapse such a flow produces a uniform gas whose velocity at each point is constant and directed towards the axis or the center, i. e. the initial condition similar to the classic solution but with a finite pressure of the converging gas. After that, a constant-velocity accretion shock propagates into the incident gas whose pressure and velocity profiles are not flat, in contrast with the classic solution. Second, for an arbitrary equation of state, we demonstrate the existence of self-similar solutions of the Noh problem in cylindrical and spherical geometry. Examples of such solutions with a three-term equation of state that includes cold, thermal ion/lattice, and thermal electron contributions are presented for aluminum and copper. These analytic solutions are compared to our numerical simulation results as an example of their use for code verification. Work supported by the US DOE/NNSA.

Ideal Theory in Semigroups Based on Intersectional Soft Sets

PubMed Central

Song, Seok Zun; Jun, Young Bae

2014-01-01

The notions of int-soft semigroups and int-soft left (resp., right) ideals are introduced, and several properties are investigated. Using these notions and the notion of inclusive set, characterizations of subsemigroups and left (resp., right) ideals are considered. Using the notion of int-soft products, characterizations of int-soft semigroups and int-soft left (resp., right) ideals are discussed. We prove that the soft intersection of int-soft left (resp., right) ideals (resp., int-soft semigroups) is also int-soft left (resp., right) ideals (resp., int-soft semigroups). The concept of int-soft quasi-ideals is also introduced, and characterization of a regular semigroup is discussed. PMID:25101310

Ideal Teacher Behaviors: Student Motivation and Self-Efficacy Predict Preferences

ERIC Educational Resources Information Center

Komarraju, Meera

2013-01-01

Differences in students' academic self-efficacy and motivation were examined in predicting preferred teacher traits. Undergraduates (261) completed the Teaching Behavior Checklist, Academic Self-Concept scale, and Academic Motivation scale. Hierarchical regression analyses indicated that academic self-efficacy and extrinsic motivation explained…

Electrochemical Behavior of Al-B4C Metal Matrix Composites in NaCl Solution

PubMed Central

Han, Yu-Mei; Chen, X.-Grant

2015-01-01

Aluminum based metal matrix composites (MMCs) have received considerable attention in the automotive, aerospace and nuclear industries. One of the main challenges using Al-based MMCs is the influence of the reinforcement particles on the corrosion resistance. In the present study, the corrosion behavior of Al-B4C MMCs in a 3.5 wt.% NaCl solution were investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Results indicated that the corrosion resistance of the composites decreased when increasing the B4C volume fraction. Al-B4C composite was susceptible to pitting corrosion and two types of pits were observed on the composite surface. The corrosion mechanism of the composite in the NaCl solution was primarily controlled by oxygen diffusion in the solution. In addition, the galvanic couples that formed between Al matrix and B4C particles could also be responsible for the lower corrosion resistance of the composites. PMID:28793574

Maintaining ideal body weight counseling sessions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brammer, S.H.

The purpose of this program is to provide employees with the motivation, knowledge and skills necessary to maintain ideal body weight throughout life. The target audience for this program, which is conducted in an industrial setting, is the employee 40 years of age or younger who is at or near his/her ideal body weight.

Artificial neural network implementation of a near-ideal error prediction controller

NASA Technical Reports Server (NTRS)

Mcvey, Eugene S.; Taylor, Lynore Denise

1992-01-01

responses be known for a particular input and modeled plant. These responses are used in the error prediction controller. An analysis was done on the general dynamic behavior that results from including a digital error predictor in a control loop and these were compared to those including the near-ideal Neural Network error predictor. This analysis was done for a second and third order system.

The Ideal Man and Woman According to University Students

ERIC Educational Resources Information Center

Weinstein, Lawrence; Laverghetta, Antonio V.; Peterson, Scott A.

2009-01-01

The present study determined if the ideal man has changed over the years and who and what the ideal woman is. We asked students at Cameron University to rate the importance of character traits that define the ideal man and woman. Subjects also provided examples of famous people exemplifying the ideal, good, average, and inferior man and woman. We…

From ideals to deals-The effect of impartiality experience on stakeholder behavior.

PubMed

Halko, Marja-Liisa; Miettinen, Topi

2017-01-01

In this paper, we study a two-party pie-sharing problem in the presence of asymmetries in the stakeholders' private endowments. Both the two stakeholders and third-party arbitrators may influence the outcome. We consider Nash-demand negotiations, where the two stakeholders place demands and share the pie accordingly if demands are compatible, and elicit dictatorial allocations from the stakeholders and the arbitrators. The Nash demands by stakeholders are strategic; the dictatorial allocations by stakeholders and arbitrators are non-strategic. We are interested in the influence of the past arbitrator experience on stakeholder allocations and demands and the past stakeholder experience on third-party arbitration allocations. We find that the ex-arbitrators' stakeholder allocations differ more from the impartial ideal than the stakeholder allocations by those without arbitration experience. In contrast with previous findings, the arbitration outcomes do not depend on the asymmetries in the previous stakeholder roles.

From ideals to deals—The effect of impartiality experience on stakeholder behavior

PubMed Central

2017-01-01

In this paper, we study a two-party pie-sharing problem in the presence of asymmetries in the stakeholders' private endowments. Both the two stakeholders and third-party arbitrators may influence the outcome. We consider Nash-demand negotiations, where the two stakeholders place demands and share the pie accordingly if demands are compatible, and elicit dictatorial allocations from the stakeholders and the arbitrators. The Nash demands by stakeholders are strategic; the dictatorial allocations by stakeholders and arbitrators are non-strategic. We are interested in the influence of the past arbitrator experience on stakeholder allocations and demands and the past stakeholder experience on third-party arbitration allocations. We find that the ex-arbitrators' stakeholder allocations differ more from the impartial ideal than the stakeholder allocations by those without arbitration experience. In contrast with previous findings, the arbitration outcomes do not depend on the asymmetries in the previous stakeholder roles. PMID:28786988

Dispersive—diffusive transport of non-sorbed solute in multicomponent solutions

NASA Astrophysics Data System (ADS)

Hu, Qinhong; Brusseau, Mark L.

1995-10-01

The composition of fuels, mixed-solvent wastes and other contaminants that find their way into the subsurface are frequently chemically complex. The dispersion and diffusion characteristics of multicomponent solutions in soil have rarely been compared to equivalent single-solute systems. The purpose of this work was to examine the diffusive and dispersive transport of single- and multi-component solutions in homogeneous porous media. The miscible displacement technique was used to investigate the transport behavior of 14C-labelled 2,4-dichlorophenoxyacetic acid ( 2,4-D) in two materials for which sorption of 2,4-D was minimal. Comparison of breakthrough curves collected for 2,4-D in single- and multi-component solutions shows that there is little, if any, difference in transport behavior over a wide range of pore-water velocities (70, 7, 0.66 and 0.06 cm h -1). Thus, dispersivities measured with a non-sorbing single-solute solution should be applicable to multicomponent systems.

Influence and adjustment goals: sources of cultural differences in ideal affect.

PubMed

Tsai, Jeanne L; Miao, Felicity F; Seppala, Emma; Fung, Helene H; Yeung, Dannii Y

2007-06-01

Previous studies have found that in American culture high-arousal positive states (HAP) such as excitement are valued more and low-arousal positive states (LAP) such as calm are valued less than they are in Chinese culture. What specific factors account for these differences? The authors predicted that when people and cultures aimed to influence others (i.e., assert personal needs and change others' behaviors to meet those needs), they would value HAP more and LAP less than when they aimed to adjust to others (i.e., suppress personal needs and change their own behaviors to meet others' needs). They test these predictions in 1 survey and 3 experimental studies. The findings suggest that within and across American and Chinese contexts, differences in ideal affect are due to specific interpersonal goals. (c) 2007 APA, all rights reserved.

Magnetogasdynamics shock waves in a rotational axisymmetric non-ideal gas with increasing energy and conductive and radiative heat-fluxes

NASA Astrophysics Data System (ADS)

Nath, Gorakh

2016-07-01

Self-similar solutions are obtained for one-dimensional adiabatic flow behind a magnetogasdynamics cylindrical shock wave propagating in a rotational axisymmetric non ideal gas with increasing energy and conductive and radiative heat fluxes in presence of an azimuthal magnetic field. The fluid velocities and the azimuthal magnetic field in the ambient medium are assume to be varying and obeying power laws. In order to find the similarity solutions the angular velocity of the ambient medium is taken to be decreasing as the distance from the axis increases. The heat conduction is expressed in terms of Fourier's law and the radiation is considered to be the diffusion type for an optically thick grey gas model. The thermal conductivity and the absorption coefficient are assumed to vary with temperature and density. The effects of the presence of radiation and conduction, the non-idealness of the gas and the magnetic field on the shock propagation and the flow behind the shock are investigated.

Two-lattice models of trace element behavior: A response

NASA Astrophysics Data System (ADS)

Ellison, Adam J. G.; Hess, Paul C.

1990-08-01

Two-lattice melt components of Bottinga and Weill (1972), Nielsen and Drake (1979), and Nielsen (1985) are applied to major and trace element partitioning between coexisting immiscible liquids studied by RYERSON and Hess (1978) and Watson (1976). The results show that (1) the set of components most successful in one system is not necessarily portable to another system; (2) solution non-ideality within a sublattice severely limits applicability of two-lattice models; (3) rigorous application of two-lattice melt components may yield effective partition coefficients for major element components with no physical interpretation; and (4) the distinction between network-forming and network-modifying components in the sense of the two-lattice models is not clear cut. The algebraic description of two-lattice models is such that they will most successfully limit the compositional dependence of major and trace element solution behavior when the effective partition coefficient of the component of interest is essentially the same as the bulk partition coefficient of all other components within its sublattice.

Dynamical heterogeneity in a glass-forming ideal gas.

PubMed

Charbonneau, Patrick; Das, Chinmay; Frenkel, Daan

2008-07-01

We conduct a numerical study of the dynamical behavior of a system of three-dimensional "crosses," particles that consist of three mutually perpendicular line segments of length sigma rigidly joined at their midpoints. In an earlier study [W. van Ketel, Phys. Rev. Lett. 94, 135703 (2005)] we showed that this model has the structural properties of an ideal gas, yet the dynamical properties of a strong glass former. In the present paper we report an extensive study of the dynamical heterogeneities that appear in this system in the regime where glassy behavior sets in. On the one hand, we find that the propensity of a particle to diffuse is determined by the structure of its local environment. The local density around mobile particles is significantly less than the average density, but there is little clustering of mobile particles, and the clusters observed tend to be small. On the other hand, dynamical susceptibility results indicate that a large dynamical length scale develops even at moderate densities. This suggests that propensity and other mobility measures are an incomplete measure of the dynamical length scales in this system.

Using NMR Spectroscopy to Investigate the Solution Behavior of Nerve Agents and Their Binding to Acetylcholinesterase

DTIC Science & Technology

2016-01-01

USING NMR SPECTROSCOPY TO INVESTIGATE THE SOLUTION BEHAVIOR OF NERVE AGENTS AND THEIR BINDING TO...XX-01-2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) Jan – Jun 2015 4. TITLE AND SUBTITLE Using NMR Spectroscopy to Investigate the...MOLECULAR MOTIONS AND NMR SPECTROSCOPY ...................................................................................................3 4. THE

Cumulative effect of psychosocial factors in youth on ideal cardiovascular health in adulthood: the Cardiovascular Risk in Young Finns Study.

PubMed

Pulkki-Råback, Laura; Elovainio, Marko; Hakulinen, Christian; Lipsanen, Jari; Hintsanen, Mirka; Jokela, Markus; Kubzansky, Laura D; Hintsa, Taina; Serlachius, Anna; Laitinen, Tomi T; Laitinen, Tomi; Pahkala, Katja; Mikkilä, Vera; Nevalainen, Jaakko; Hutri-Kähönen, Nina; Juonala, Markus; Viikari, Jorma; Raitakari, Olli T; Keltikangas-Järvinen, Liisa

2015-01-20

The American Heart Association has defined a new metric of ideal cardiovascular health as part of its 2020 Impact Goals. We examined whether psychosocial factors in youth predict ideal cardiovascular health in adulthood. Participants were 477 men and 612 women from the nationwide Cardiovascular Risk in Young Finns Study. Psychosocial factors were measured from cohorts 3 to 18 years of age at the baseline of the study, and ideal cardiovascular health was examined 27 years later in adulthood. The summary measure of psychosocial factors in youth comprised socioeconomic factors, emotional factors, parental health behaviors, stressful events, self-regulation of the child, and social adjustment of the child. There was a positive association between a higher number of favorable psychosocial factors in youth and greater ideal cardiovascular health index in adulthood (β=0.16; P<0.001) that persisted after adjustment for age, sex, medication use, and cardiovascular risk factors in childhood (β=0.15; P<0.001). The association was monotonic, suggesting that each increment in favorable psychosocial factors was associated with improvement in cardiovascular health. Of the specific psychosocial factors, a favorable socioeconomic environment (β=0.12; P<0.001) and participants' self-regulatory behavior (β=0.07; P=0.004) were the strongest predictors of ideal cardiovascular health in adulthood. The findings suggest a dose-response association between favorable psychosocial factors in youth and cardiovascular health in adulthood, as defined by the American Heart Association metrics. The effect seems to persist throughout the range of cardiovascular health, potentially shifting the population distribution of cardiovascular health rather than simply having effects in a high-risk population. © 2015 American Heart Association, Inc.

High energy supercapattery with an ionic liquid solution of LiClO4.

PubMed

Yu, Linpo; Chen, George Z

2016-08-15

A supercapattery combining an ideally polarized capacitor-like electrode and a battery-like electrode is demonstrated theoretically and practically using an ionic liquid electrolyte containing 1-butyl-1-methylpyrrolidinium tri(pentafluoroethyl)trifluorophosphate (BMPyrrFAP), gamma-butyrolactone (γ-GBL) and LiClO4. The electrochemical deposition and dissolution of lithium metal on a platinum and glass carbon electrode were investigated in this ionic liquid solution. The CVs showed that the fresh electrochemically deposited lithium metal was stable in the electrolyte, which encouraged the investigation of this ionic liquid solution in a supercapattery with a lithium battery negative electrode. The active material counted specific energy of the supercapattery based on a lithium negative electrode and an activated carbon (Act-C) positive electrode could reach 230 W h kg(-1) under a galvanostatic charge-discharge current density of 1 mA cm(-2). The positive electrode material (Act-C) was also investigated by CV, AC impedance, SEM and BET. The non-uniform particle size and micropores dominated porous structure of the Act-C enabled its electric double layer capacitor (EDLC) behavior in the ionic liquid solution. The measured specific capacitance of the Act-C in this ionic liquid solution is higher than the same Act-C in aqueous solution, which indicates the Act-C can also perform well in the ionic liquid electrolyte.

Electrochemical Behavior Assessment of Micro- and Nano-Grained Commercial Pure Titanium in H2SO4 Solutions

NASA Astrophysics Data System (ADS)

Fattah-alhosseini, Arash; Ansari, Ali Reza; Mazaheri, Yousef; Karimi, Mohsen

2017-02-01

In this study, the electrochemical behavior of commercial pure titanium with both coarse-grained (annealed sample with the average grain size of about 45 µm) and nano-grained microstructure was compared by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis. Nano-grained Ti, which typically has a grain size of about 90 nm, is successfully made by six-cycle accumulative roll-bonding process at room temperature. Potentiodynamic polarization plots and impedance measurements revealed that as a result of grain refinement, the passive behavior of the nano-grained sample was improved compared to that of annealed pure Ti in H2SO4 solutions. Mott-Schottky analysis indicated that the passive films behaved as n-type semiconductors in H2SO4 solutions and grain refinement did not change the semiconductor type of passive films. Also, Mott-Schottky analysis showed that the donor densities decreased as the grain size of the samples reduced. Finally, all electrochemical tests showed that the electrochemical behavior of the nano-grained sample was improved compared to that of annealed pure Ti, mainly due to the formation of thicker and less defective oxide film.

Idealism and materialism in perception.

PubMed

Rose, David; Brown, Dora

2015-01-01

Koenderink (2014, Perception, 43, 1-6) has said most Perception readers are deluded, because they believe an 'All Seeing Eye' observes an objective reality. We trace the source of Koenderink's assertion to his metaphysical idealism, and point to two major weaknesses in his position-namely, its dualism and foundationalism. We counter with arguments from modern philosophy of science for the existence of an objective material reality, contrast Koenderink's enactivism to his idealism, and point to ways in which phenomenology and cognitive science are complementary and not mutually exclusive.

Quantitative Characterization of Magnetic Mobility of Nanoparticle in Solution-Based Condition.

PubMed

Rodoplu, Didem; Boyaci, Ismail H; Bozkurt, Akif G; Eksi, Haslet; Zengin, Adem; Tamer, Ugur; Aydogan, Nihal; Ozcan, Sadan; Tugcu-Demiröz, Fatmanur

2015-01-01

Magnetic nanoparticles are considered as the ideal substrate to selectively isolate target molecules or organisms from sample solutions in a wide variety of applications including bioassays, bioimaging and environmental chemistry. The broad array of these applications in fields requires the accurate magnetic characterization of nanoparticles for a variety of solution based-conditions. Because the freshly synthesized magnetic nanoparticles demonstrated a perfect magnetization value in solid form, they exhibited a different magnetic behavior in solution. Here, we present simple quantitative method for the measurement of magnetic mobility of nanoparticles in solution-based condition. Magnetic mobility of the nanoparticles was quantified with initial mobility of the particles using UV-vis absorbance spectroscopy in water, ethanol and MES buffer. We demonstrated the efficacy of this method through a systematic characterization of four different core-shell structures magnetic nanoparticles over three different surface modifications. The solid nanoparticles were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and saturation magnetization (Ms). The surfaces of the nanoparticles were functionalized with 11-mercaptoundecanoic acid and bovine serum albumin BSA was selected as biomaterial. The effect of the surface modification and solution media on the stability of the nanoparticles was monitored by zeta potentials and hydrodynamic diameters of the nanoparticles. Results obtained from the mobility experiments indicate that the initial mobility was altered with solution media, surface functionalization, size and shape of the magnetic nanoparticle. The proposed method easily determines the interactions between the magnetic nanoparticles and their surrounding biological media, the magnetophoretic responsiveness of nanoparticles and the initial mobilities of the nanoparticles.

Multiprobe Spectroscopic Inverstigation of Molecular-level Behavior within Aqueous 1-Butyl-3-methylimidazolium Tetrafluoroborate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, Abhra; Ali, Maroof; Baker, Gary A

2009-01-01

In this work, an array of molecular-level solvent featuressincluding solute-solvent/solvent-solvent interactions, dipolarity, heterogeneity, dynamics, probe accessibility, and diffusionswere investigated across the entire composition of ambient mixtures containing the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4], and pH 7.0 phosphate buffer, based on results assembled for nine different molecular probes utilized in a range of spectroscopic modes. These studies uncovered interesting and unusual solvatochromic probe behavior within this benchmark mixture. Solvatochromic absorbance probessa watersoluble betaine dye (betaine dye 33), N,N-diethyl-4-nitroaniline, and 4-nitroanilineswere employed to determine ET (a blend of dipolarity/polarizability and hydrogen bond donor contributions) and the Kamlet-Taft indices * (dipolarity/polarizability), R (hydrogenmore » bond donor acidity), and (hydrogen bond acceptor basicity) characterizing the [bmim][BF4] + phosphate buffer system. These parameters each showed a marked deviation from ideality, suggesting selective solvation of the individual probe solutes by [bmim][BF4]. Similar conclusions were derived from the responses of the fluorescent polarity-sensitive probes pyrene and pyrene-1-carboxaldehyde. Importantly, the fluorescent microfluidity probe 1,3-bis(1-pyrenyl)propane senses a microviscosity within the mixture that significantly exceeds expectations derived from simple interpolation of the behavior in the neat solvents. On the basis of results from this probe, a correlation between microviscosity and bulk viscosity was established; pronounced solvent-solvent hydrogen-bonding interactions were implicit in this behavior. The greatest deviation from ideal additive behavior for the probes studied herein was consistently observed to occur in the buffer-rich regime. Nitromethane-based fluorescence quenching of pyrene within the [bmim][BF4] + phosphate buffer system showed unusual compliance with

Numerical Solutions for Supersonic Flow of an Ideal Gas Around Blunt Two-Dimensional Bodies

NASA Technical Reports Server (NTRS)

Fuller, Franklyn B.

1961-01-01

The method described is an inverse one; the shock shape is chosen and the solution proceeds downstream to a body. Bodies blunter than circular cylinders are readily accessible, and any adiabatic index can be chosen. The lower limit to the free-stream Mach number available in any case is determined by the extent of the subsonic field, which in turn depends upon the body shape. Some discussion of the stability of the numerical processes is given. A set of solutions for flows about circular cylinders at several Mach numbers and several values of the adiabatic index is included.

The three-class ideal observer for univariate normal data: Decision variable and ROC surface properties

PubMed Central

Edwards, Darrin C.; Metz, Charles E.

2012-01-01

Although a fully general extension of ROC analysis to classification tasks with more than two classes has yet to be developed, the potential benefits to be gained from a practical performance evaluation methodology for classification tasks with three classes have motivated a number of research groups to propose methods based on constrained or simplified observer or data models. Here we consider an ideal observer in a task with underlying data drawn from three univariate normal distributions. We investigate the behavior of the resulting ideal observer’s decision variables and ROC surface. In particular, we show that the pair of ideal observer decision variables is constrained to a parametric curve in two-dimensional likelihood ratio space, and that the decision boundary line segments used by the ideal observer can intersect this curve in at most six places. From this, we further show that the resulting ROC surface has at most four degrees of freedom at any point, and not the five that would be required, in general, for a surface in a six-dimensional space to be non-degenerate. In light of the difficulties we have previously pointed out in generalizing the well-known area under the ROC curve performance metric to tasks with three or more classes, the problem of developing a suitable and fully general performance metric for classification tasks with three or more classes remains unsolved. PMID:23162165

Trauma-Focused Cognitive Behavior Therapy for School Psychologists

ERIC Educational Resources Information Center

Fitzgerald, Monica M.; Cohen, Judith A.

2012-01-01

Schools are ideal settings for identifying children and adolescents who have been exposed to traumatic events. They are also ideal for providing evidence-based mental health services, such as trauma-focused cognitive behavioral therapy, to students affected by childhood posttraumatic stress disorder and co-occurring mental health and behavioral…

The Actual and Ideal Sexual Self Concept in the Context of Genital Pain Using Implicit and Explicit Measures.

PubMed

Dewitte, Marieke; De Schryver, Maarten; Heider, Niclas; De Houwer, Jan

2017-05-01

The experience of pain during sexual intercourse generates significant distress and sexual impairments, which is likely to affect sexual identity and become a threat to the sense of self. To explore the role of the concept of the sexual self in the context of genital pain by measuring different states of self (ie, actual vs ideal) at different levels of responding (ie, explicit vs implicit) and examine their associations with sexual, emotional, and pain-related variables. Thirty young women who identified with genital pain and 29 women without pain completed (i) two versions of the Relational Responding Task as a measurement of implicit actual and ideal sexual self; (ii) explicit ratings of the actual and the ideal sexual self; and (iii) measurements of sexual self-esteem, global self-esteem, depression, sexual satisfaction, sexual distress or depression, sexual frequency, and pain experiences. Women with genital pain scored lower on the explicit and implicit actual-self measurements than women without pain but did not differ in their ideal self. Furthermore, the pain group reported higher ideal- than actual-self scores at the explicit level. Actual- and ideal-self measurements had differential effects on sexual, emotional, and behavioral outcome variables. In general, rating the ideal self higher than the actual self was related to more negative outcomes. Pain-related variables were predicted only by the implicit measurements, showing that the high pain group reported more pain, fear of pain, and a stronger tendency to continue with sex despite the pain when perceiving themselves as sexually less competent and when this perception did not match their ideal self. Therapeutic interventions might benefit from discussing women's internal guides for self, decreasing potential discrepancies, and developing identity-related motivational treatments that target the emotional discomfort and maladaptive behavioral strategies that result from trying to conform with their

Relationship Between Ideal Cardiovascular Health and Disability in Older Adults: The Chilean National Health Survey (2009-10).

PubMed

García-Hermoso, Antonio; Ramírez-Vélez, Robinson; Ramirez-Campillo, Rodrigo; Izquierdo, Mikel

2017-12-01

This study aimed to examine the relationship between disability and the American Heart Association metric of ideal cardiovascular health (CVH) in older adults from the 2009-10 Chilean National Health Survey. Data from 460 older adults were analyzed. All subjects were interviewed using the standardized World Health Survey, which includes 16 health-related questions and assesses the domains of mobility, self-care, pain and discomfort, cognition, interpersonal activities, vision, sleep and energy, and affect. A person who responds with a difficulty rating of severe, extreme, or unable to do in at least one of these eight functioning domains is considered to have a disability. Ideal CVH was defined as meeting the ideal levels of four behaviors (smoking, body mass index, physical activity, diet adherence) and three factors (total cholesterol, fasting glucose, blood pressure). Logistic regression analysis suggested that ideal physical activity reduces the odds of disability (odds ratio (OR) = 0.55, 95% confidence interval (CI) = 0.36-0.85). Moreover, participants with intermediate (3-4 metrics) (OR = 0.63, 95% CI = 0.41-0.97) and ideal (5-7 metrics) (OR = 0.51, 95% CI = 0.24-0.97) CVH profiles had lower odds of disability independent of history of vascular events and arthritis disease than those with a poor profile (0-2 metrics). In conclusion, despite the cross-sectional design, this study suggests the importance of promoting ideal CVH because of their relationship with disability. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Medical learning curves and the Kantian ideal.

PubMed

Le Morvan, P; Stock, B

2005-09-01

A hitherto unexamined problem for the "Kantian ideal" that one should always treat patients as ends in themselves, and never only as a means to other ends, is explored in this paper. The problem consists of a prima facie conflict between this Kantian ideal and the reality of medical practice. This conflict arises because, at least presently, medical practitioners can only acquire certain skills and abilities by practising on live, human patients, and given the inevitability and ubiquity of learning curves, this learning requires some patients to be treated only as a means to this end. A number of ways of attempting to establish the compatibility of the Kantian Ideal with the reality of medical practice are considered. Each attempt is found to be unsuccessful. Accordingly, until a way is found to reconcile them, we conclude that the Kantian ideal is inconsistent with the reality of medical practice.

Medical learning curves and the Kantian ideal

PubMed Central

Le Morvan, P; Stock, B

2005-01-01

A hitherto unexamined problem for the "Kantian ideal" that one should always treat patients as ends in themselves, and never only as a means to other ends, is explored in this paper. The problem consists of a prima facie conflict between this Kantian ideal and the reality of medical practice. This conflict arises because, at least presently, medical practitioners can only acquire certain skills and abilities by practising on live, human patients, and given the inevitability and ubiquity of learning curves, this learning requires some patients to be treated only as a means to this end. A number of ways of attempting to establish the compatibility of the Kantian Ideal with the reality of medical practice are considered. Each attempt is found to be unsuccessful. Accordingly, until a way is found to reconcile them, we conclude that the Kantian ideal is inconsistent with the reality of medical practice. PMID:16131552

Ta-Nb-Mo-W refractory high-entropy alloys: Anomalous ordering behavior and its intriguing electronic origin

DOE PAGES

Singh, Prashant; Smirnov, A. V.; Johnson, Duane D.

2018-05-31

From electronic-structure-based thermodynamic linear response, we establish chemical ordering behavior in complex solid solutions versus how Gibbs' space is traversed—applying it on prototype refractory A2 Ta-Nb-Mo-W high-entropy alloys. Near ideal stoichiometry, this alloy has anomalous, intricate chemical ordering tendencies, with long-ranged chemical interactions that produce competing short-range order (SRO) with a crossover to spinodal segregation. This atypical SRO arises from canonical band behavior that, with alloying, creates features near the Fermi surface (well defined even with disorder) that change to simple commensurate SRO with (un)filling of these states. In conclusion, our results reveal how complexity and competing electronic effects controlmore » ordering in these alloys.« less

Ta-Nb-Mo-W refractory high-entropy alloys: Anomalous ordering behavior and its intriguing electronic origin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Prashant; Smirnov, A. V.; Johnson, Duane D.

From electronic-structure-based thermodynamic linear response, we establish chemical ordering behavior in complex solid solutions versus how Gibbs' space is traversed—applying it on prototype refractory A2 Ta-Nb-Mo-W high-entropy alloys. Near ideal stoichiometry, this alloy has anomalous, intricate chemical ordering tendencies, with long-ranged chemical interactions that produce competing short-range order (SRO) with a crossover to spinodal segregation. This atypical SRO arises from canonical band behavior that, with alloying, creates features near the Fermi surface (well defined even with disorder) that change to simple commensurate SRO with (un)filling of these states. In conclusion, our results reveal how complexity and competing electronic effects controlmore » ordering in these alloys.« less

Analytical theory of mesoscopic Bose-Einstein condensation in an ideal gas

NASA Astrophysics Data System (ADS)

Kocharovsky, Vitaly V.; Kocharovsky, Vladimir V.

2010-03-01

We find the universal structure and scaling of the Bose-Einstein condensation (BEC) statistics and thermodynamics (Gibbs free energy, average energy, heat capacity) for a mesoscopic canonical-ensemble ideal gas in a trap with an arbitrary number of atoms, any volume, and any temperature, including the whole critical region. We identify a universal constraint-cutoff mechanism that makes BEC fluctuations strongly non-Gaussian and is responsible for all unusual critical phenomena of the BEC phase transition in the ideal gas. The main result is an analytical solution to the problem of critical phenomena. It is derived by, first, calculating analytically the universal probability distribution of the noncondensate occupation, or a Landau function, and then using it for the analytical calculation of the universal functions for the particular physical quantities via the exact formulas which express the constraint-cutoff mechanism. We find asymptotics of that analytical solution as well as its simple analytical approximations which describe the universal structure of the critical region in terms of the parabolic cylinder or confluent hypergeometric functions. The obtained results for the order parameter, all higher-order moments of BEC fluctuations, and thermodynamic quantities perfectly match the known asymptotics outside the critical region for both low and high temperature limits. We suggest two- and three-level trap models of BEC and find their exact solutions in terms of the cutoff negative binomial distribution (which tends to the cutoff gamma distribution in the continuous limit) and the confluent hypergeometric distribution, respectively. Also, we present an exactly solvable cutoff Gaussian model of BEC in a degenerate interacting gas. All these exact solutions confirm the universality and constraint-cutoff origin of the strongly non-Gaussian BEC statistics. We introduce a regular refinement scheme for the condensate statistics approximations on the basis of the

Interferograms, schlieren, and shadowgraphs constructed from real- and ideal-gas, two- and three-dimensional computed flowfields

NASA Technical Reports Server (NTRS)

Yates, Leslie A.

1993-01-01

The construction of interferograms, schlieren, and shadowgraphs from computed flowfield solutions permits one-to-one comparisons of computed and experimental results. A method of constructing these images from both ideal- and real-gas, two and three-dimensional computed flowfields is described. The computational grids can be structured or unstructured, and multiple grids are an option. Constructed images are shown for several types of computed flows including nozzle, wake, and reacting flows; comparisons to experimental images are also shown. In addition, th sensitivity of these images to errors in the flowfield solution is demonstrated, and the constructed images can be used to identify problem areas in the computations.

Interferograms, Schlieren, and Shadowgraphs Constructed from Real- and Ideal-Gas, Two- and Three-Dimensional Computed Flowfields

NASA Technical Reports Server (NTRS)

Yates, Leslie A.

1992-01-01

The construction of interferograms, schlieren, and shadowgraphs from computed flowfield solutions permits one-to-one comparisons of computed and experimental results. A method for constructing these images from both ideal- and real-gas, two- and three-dimensional computed flowfields is described. The computational grids can be structured or unstructured, and multiple grids are an option. Constructed images are shown for several types of computed flows including nozzle, wake, and reacting flows; comparisons to experimental images are also shown. In addition, the sensitivity of these images to errors in the flowfield solution is demonstrated, and the constructed images can be used to identify problem areas in the computations.

Solution behavior of metoclopramide in aqueous-alcoholic solutions at 30°C

NASA Astrophysics Data System (ADS)

Deosarkar, S. D.; Sawale, R. T.; Tawde, P. D.; Kalyankar, T. M.

2016-07-01

Densities (ρ) and refractive indices ( n D) of solutions of antiemetic drug metoclopramide (4-amino-5-chloro- N-(2-(diethylamino)ethyl)-2-methoxybenzamide hydrochloride hydrate) in methanolwater and ethanol-water mixtures of different compositions were measured at 30°C. Apparent molar volume (φv) of the drug was calculated from density data and partial molar volumes (φ v 0 ) were determined from Massons relation. Concentration dependence of nD has been studied to determine refractive indices of solution at infinite dilution ( n D 0 ). Results have been interpreted in terms of solute-solvent interactions.

The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films

NASA Astrophysics Data System (ADS)

Ren, Jianjun; Zuo, Yu

2012-11-01

The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films were studied. The voltage-time response for galvanostatic anodization of aluminum in malonic acid solution exhibits a conventional three-stage feature but the formation voltage is much higher. With the increase of electrolyte concentration, the electrolyte viscosity increases simultaneously and the high viscosity decreases the film growth rate. With the concentration increase of the malonic acid electrolyte, the critical current density that initiates local "burning" on the sample surface decreases. For malonic acid anodization, the field-assisted dissolution on the oxide surface is relatively weak and the nucleation of pores is more difficult, which results in greater barrier layer thickness and larger cell dimension. The embryo of the porous structure of anodic film has been created within the linear region of the first transient stage, and the definite porous structure has been established before the end of the first transient stage. The self-ordering behavior of the porous film is influenced by the electrolyte concentration, film thickness and the applied current density. Great current density not only improves the cell arrangement order but also brings about larger cell dimension.

Boltzmann equations for a binary one-dimensional ideal gas.

PubMed

Boozer, A D

2011-09-01

We consider a time-reversal invariant dynamical model of a binary ideal gas of N molecules in one spatial dimension. By making time-asymmetric assumptions about the behavior of the gas, we derive Boltzmann and anti-Boltzmann equations that describe the evolution of the single-molecule velocity distribution functions for an ensemble of such systems. We show that for a special class of initial states of the ensemble one can obtain an exact expression for the N-molecule velocity distribution function, and we use this expression to rigorously prove that the time-asymmetric assumptions needed to derive the Boltzmann and anti-Boltzmann equations hold in the limit of large N. Our results clarify some subtle issues regarding the origin of the time asymmetry of Boltzmann's H theorem.

[The style of leadership idealized by nurses].

PubMed

Higa, Elza de Fátima Ribeiro; Trevizan, Maria Auxiliadora

2005-01-01

This study focuses on nursing leadership on the basis of Grid theories. According to the authors, these theories are an alternative that allows for leadership development in nursing. The research aimed to identify and analyze the style of leadership idealized by nurses, according to their own view, and to compare the styles of leadership idealized by nurses between the two research institutions. Study subjects were 13 nurses. The results show that nurses at both institutions equally mention they idealize style 9.9, followed by 5.5 and 1.9, with a tendency to reject styles 9.1 and 1.1.

Is the Ideal Mother a Sensitive Mother? Beliefs about Early Childhood Parenting in Mothers across the Globe

ERIC Educational Resources Information Center

Mesman, Judi; van IJzendoorn, Marinus; Behrens, Kazuko; Carbonell, Olga Alicia; Cárcamo, Rodrigo; Cohen-Paraira, Inbar; de la Harpe, Christian; Ekmekçi, Hatice; Emmen, Rosanneke; Heidar, Jailan; Kondo-Ikemura, Kiyomi; Mels, Cindy; Mooya, Haatembo; Murtisari, Sylvia; Nóblega, Magaly; Ortiz, Jenny Amanda; Sagi-Schwartz, Abraham; Sichimba, Francis; Soares, Isabel; Steele, Howard; Steele, Miriam; Pape, Marloes; van Ginkel, Joost; van der Veer, René; Wang, Lamei; Selcuk, Bilge; Yavuz, Melis; Zreik, Ghadir

2016-01-01

In this article, we test the hypothesis that beliefs about the ideal mother are convergent across cultures and that these beliefs overlap considerably with attachment theory's notion of the sensitive mother. In a sample including 26 cultural groups from 15 countries around the globe, 751 mothers sorted the Maternal Behavior Q-Set to reflect their…

Concepts of Ideal and Nonideal Explosives.

DTIC Science & Technology

1981-12-01

Akst and J. Hershkowitz, "Explosive Performance Modification by Cosolidifaction of Ammonium Nitrate with Fuels ," Technical Report 4987, Picatinny...explosives Equations of state Diameter effect Ammonium nitrate 20. ASSrRACr (ca’mes r w re t N netwezy ad identity by block number) The purpose of...this report is to stimulate discussion on the nonideality of ammonium nitrate and its composite explosives. The concept of ideal and non- ideal

STABILITY OF A CYLINDRICAL SOLUTE-SOLVENT INTERFACE: EFFECT OF GEOMETRY, ELECTROSTATICS, AND HYDRODYNAMICS.

PubMed

Li, B O; Sun, Hui; Zhou, Shenggao

The solute-solvent interface that separates biological molecules from their surrounding aqueous solvent characterizes the conformation and dynamics of such molecules. In this work, we construct a solvent fluid dielectric boundary model for the solvation of charged molecules and apply it to study the stability of a model cylindrical solute-solvent interface. The motion of the solute-solvent interface is defined to be the same as that of solvent fluid at the interface. The solvent fluid is assumed to be incompressible and is described by the Stokes equation. The solute is modeled simply by the ideal-gas law. All the viscous force, hydrostatic pressure, solute-solvent van der Waals interaction, surface tension, and electrostatic force are balanced at the solute-solvent interface. We model the electrostatics by Poisson's equation in which the solute-solvent interface is treated as a dielectric boundary that separates the low-dielectric solute from the high-dielectric solvent. For a cylindrical geometry, we find multiple cylindrically shaped equilibrium interfaces that describe polymodal (e.g., dry and wet) states of hydration of an underlying molecular system. These steady-state solutions exhibit bifurcation behavior with respect to the charge density. For their linearized systems, we use the projection method to solve the fluid equation and find the dispersion relation. Our asymptotic analysis shows that, for large wavenumbers, the decay rate is proportional to wavenumber with the proportionality half of the ratio of surface tension to solvent viscosity, indicating that the solvent viscosity does affect the stability of a solute-solvent interface. Consequences of our analysis in the context of biomolecular interactions are discussed.

Superhydrophobic ceramic coating: Fabrication by solution precursor plasma spray and investigation of wetting behavior.

PubMed

Xu, Pengyun; Coyle, Thomas W; Pershin, Larry; Mostaghimi, Javad

2018-08-01

Superhydrophobic surfaces are often created by fabricating suitable surface structures from low-surface-energy organic materials using processes that are not suitable for large-scale fabrication. Rare earth oxides (REO) exhibit hydrophobic behavior that is unusual among oxides. Solution precursor plasma spray (SPPS) deposition is a rapid, one-step process that can produce ceramic coatings with fine scale columnar structures. Manipulation of the structure of REO coatings through variation in deposition conditions may allow the wetting behavior to be controlled. Yb 2 O 3 coatings were fabricated via SPPS. Coating structure was investigated by scanning electron microscopy, digital optical microscopy, and x-ray diffraction. The static water contact angle and roll-off angle were measured, and the dynamic impact of water droplets on the coating surface recorded. Superhydrophobic behavior was observed; the best coating exhibited a water contact angle of ∼163°, a roll-off angle of ∼6°, and complete droplet rebound behavior. All coatings were crystalline Yb 2 O 3 , with a nano-scale roughness superimposed on a micron-scale columnar structure. The wetting behaviors of coatings deposited at different standoff distances were correlated with the coating microstructures and surface topographies. The self-cleaning, water flushing and water jetting tests were conducted and further demonstrated the excellent and durable hydrophobicity of the coatings. Copyright © 2018 Elsevier Inc. All rights reserved.

Freezing point depression in model Lennard-Jones solutions

NASA Astrophysics Data System (ADS)

Koschke, Konstantin; Jörg Limbach, Hans; Kremer, Kurt; Donadio, Davide

2015-09-01

Crystallisation of liquid solutions is of uttermost importance in a wide variety of processes in materials, atmospheric and food science. Depending on the type and concentration of solutes the freezing point shifts, thus allowing control on the thermodynamics of complex fluids. Here we investigate the basic principles of solute-induced freezing point depression by computing the melting temperature of a Lennard-Jones fluid with low concentrations of solutes, by means of equilibrium molecular dynamics simulations. The effect of solvophilic and weakly solvophobic solutes at low concentrations is analysed, scanning systematically the size and the concentration. We identify the range of parameters that produce deviations from the linear dependence of the freezing point on the molal concentration of solutes, expected for ideal solutions. Our simulations allow us also to link the shifts in coexistence temperature to the microscopic structure of the solutions.

Ideal and Nonideal Reasoning in Educational Theory

ERIC Educational Resources Information Center

Jaggar, Alison M.

2015-01-01

The terms "ideal theory" and "nonideal theory" are used in contemporary Anglophone political philosophy to identify alternative methodological approaches for justifying normative claims. Each term is used in multiple ways. In this article Alison M. Jaggar disentangles several versions of ideal and nonideal theory with a view to…

Idealized cultural beliefs about gender: implications for mental health.

PubMed

Mahalingam, Ramaswami; Jackson, Benita

2007-12-01

In this paper, we examined the relationship between culture-specific ideals (chastity, masculinity, caste beliefs) and self-esteem, shame and depression using an idealized cultural model proposed by Mahalingam (2006, In: Mahalingam R (ed) Cultural psychology of immigrants. Lawrence Erlbaum, Mahwah, NJ, pp 1-14). Participants were from communities with a history of extreme male-biased sex ratios in Tamilnadu, India (N = 785). We hypothesized a dual-process model of self-appraisals suggesting that achieving idealized cultural identities would increase both self-esteem and shame, with the latter leading to depression, even after controlling for key covariates. We tested this using structural equation modeling. The proposed idealized cultural identities model had an excellent fit (CFI = 0.99); the effect of idealized identities on self-esteem, shame and depression differed by gender. Idealized beliefs about gender relate to psychological well-being in gender specific ways in extreme son preference communities. We discuss implications of these findings for future research and community-based interventions.

Cognitive Distortions Associated with Imagination of the Thin Ideal: Validation of the Thought-Shape Fusion Body Questionnaire (TSF-B)

PubMed Central

Wyssen, Andrea; Debbeler, Luka J.; Meyer, Andrea H.; Coelho, Jennifer S.; Humbel, Nadine; Schuck, Kathrin; Lennertz, Julia; Messerli-Bürgy, Nadine; Biedert, Esther; Trier, Stephan N.; Isenschmid, Bettina; Milos, Gabriella; Whinyates, Katherina; Schneider, Silvia; Munsch, Simone

2017-01-01

Thought-shape fusion (TSF) describes the experience of body-related cognitive distortions associated with eating disorder (ED) pathology. In the laboratory TSF has been activated by thoughts about fattening/forbidden foods and thin ideals. This study aims at validating a questionnaire to assess the trait susceptibility to TSF (i.e., body-related cognitive distortions) associated with the imagination of thin ideals, and developing an adapted version of the original TSF trait questionnaire, the Thought-Shape Fusion Body Questionnaire (TSF-B). Healthy control women (HC, n = 317) and women diagnosed with subthreshold and clinical EDs (n = 243) completed an online-questionnaire. The factor structure of the TSF-B questionnaire was examined using exploratory (EFA) and subsequent confirmatory factor analysis (CFA). EFA pointed to a two-factor solution, confirmed by CFA. Subscale 1 was named Imagination of thin ideals, containing five items referring to the imagination of female thin ideals. Subscale 2 was named Striving for own thin ideal, with seven items about pursuing/abandoning attempts to reach one’s own thin ideal. The total scale and both subscales showed good convergent validity, excellent reliability, and good ability to discriminate between individuals with subthreshold/clinical EDs and HCs. Results indicate that cognitive distortions are also related to the imagination of thin ideals, and are associated with ED pathology. With two subscales, the TSF-B trait questionnaire appropriately measures this construct. Future studies should clarify whether TSF-B is predictive for the development and course of EDs. Assessing cognitive distortions with the TSF-B questionnaire could improve understanding of EDs and stimulate the development of cognitively oriented interventions. Clinical Trial Registration Number: DRKS-ID: DRKS00005709. PMID:29312059

The relationship between dieting and body image, body ideal, self-perception, and body mass index in Turkish adolescents.

PubMed

Canpolat, Banu Isik; Orsel, Sibel; Akdemir, Asena; Ozbay, M Haluk

2005-03-01

The current study examined the roles of body image, ideal body weight, self-perception, and body mass index (BMI) on the dieting behavior of Turkish adolescents. The 531 subjects who participated in the study ranged from 15 to 17 years old and were recruited from five selected high schools in Ankara. They completed the Self-Perception Profile for Adolescents (SPPA), the Body Image Satisfaction Questionnaire (BISQ), and the Dieting Status Measure (DiSM). Height and weight were measured. Dieting adolescents received significantly lower scores than nondieters for most of the BISQ items and for the physical appearance and global self-worth subscales of the SPPA. A thinner body ideal, the physical appearance domain of self-concept, and low global self-worth were the predicting factors of frequent dieting. However, BMI and body image dissatisfaction were not predicting factors. The results indicate that a thinner body ideal, low self-worth, and low physical self-concept have more significant effects on body dissatisfaction and dieting than being actually overweight does. Furthermore, high physical self-concept scores and body satisfaction may not necessarily preclude having a thinner body ideal and, hence, dieting in girls. (c) 2005 by Wiley Periodicals, Inc.

Heat-flow equation motivated by the ideal-gas shock wave.

PubMed

Holian, Brad Lee; Mareschal, Michel

2010-08-01

We present an equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, in order to model shockwave propagation in gases. Our approach is motivated by the observation of a disequilibrium among the three components of temperature, namely, the difference between the temperature component in the direction of a planar shock wave, versus those in the transverse directions. This difference is most prominent near the shock front. We test our heat-flow equation for the case of strong shock waves in the ideal gas, which has been studied in the past and compared to Navier-Stokes solutions. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations of hard spheres under strong shockwave conditions.

Impact of an Exhaust Throat on Semi-Idealized Rotating Detonation Engine Performance

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.

2016-01-01

A computational fluid dynamic (CFD) model of a rotating detonation engine (RDE) is used to examine the impact of an exhaust throat (i.e. a constriction) on performance. The model simulates an RDE which is premixed, adiabatic, inviscid, and which contains an inlet valve that prevents backflow from the high pressure region directly behind the rotating detonation. Performance is assessed in terms of ideal net specific impulse which is computed on the assumption of lossless expansion of the working fluid to the ambient pressure through a notional diverging nozzle section downstream of the throat. Such a semi-idealized analysis, while not real-world, allows the effect of the throat to be examined in isolation from, rather than coupled to (as it actually is) various loss mechanisms. For the single Mach 1.4 flight condition considered, it is found that the addition of a throat can yield a 9.4 percent increase in specific impulse. However, it is also found that when the exit throat restriction gets too small, an unstable type of operation ensues which eventually leads to the detonation failing. This behavior is found to be somewhat mitigated by the addition of an RDE inlet restriction across which there is an aerodynamic loss. Remarkably, this loss is overcome by the benefits of the further exhaust restrictions allowed. The end result is a configuration with a 10.3 percent improvement in ideal net specific thrust.

Impact of an Exhaust Throat on Semi-Idealized Rotating Detonation Engine Performance

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.

2016-01-01

A computational fluid dynamic (CFD) model of a rotating detonation engine (RDE) is used to examine the impact of an exhaust throat (i.e., a constriction) on performance. The model simulates an RDE which is premixed, adiabatic, inviscid, and which contains an inlet valve that prevents backflow from the high pressure region directly behind the rotating detonation. Performance is assessed in terms of ideal net specific impulse which is computed on the assumption of lossless expansion of the working fluid to the ambient pressure through a notional diverging nozzle section downstream of the throat. Such a semi-idealized analysis, while not real-world, allows the effect of the throat to be examined in isolation from, rather than coupled to (as it actually is) various loss mechanisms. For the single Mach 1.4 flight condition considered, it is found that the addition of a throat can yield a 9.4 percent increase in specific impulse. However, it is also found that when the exit throat restriction gets too small, an unstable type of operation ensues which eventually leads to the detonation failing. This behavior is found to be somewhat mitigated by the addition of an RDE inlet restriction across which there is an aerodynamic loss. Remarkably, this loss is overcome by the benefits of the further exhaust restrictions allowed. The end result is a configuration with a 10.3 percent improvement in ideal net specific thrust.

Susceptibility for thin ideal media and eating styles.

PubMed

Anschutz, Doeschka J; Engels, Rutger C M E; Van Strien, Tatjana

2008-03-01

This study examined the relations between susceptibility for thin ideal media and restrained, emotional and external eating, directly and indirectly through body dissatisfaction. Thin ideal media susceptibility, body dissatisfaction and eating styles were measured in a sample of 163 female students. Structural equation modelling was used for analyses, controlling for BMI. Higher susceptibility for thin ideal media was directly related to higher scores on all eating styles, and indirectly related to higher restrained and emotional eating through elevated levels of body dissatisfaction. So, thin ideal media susceptibility was not only related to restraint through body dissatisfaction, but also directly. Emotional eaters might be more vulnerable for negative affect, whereas external eaters might be more sensitive to external cues in general.

Numerical solutions of ideal quantum gas dynamical flows governed by semiclassical ellipsoidal-statistical distribution.

PubMed

Yang, Jaw-Yen; Yan, Chih-Yuan; Diaz, Manuel; Huang, Juan-Chen; Li, Zhihui; Zhang, Hanxin

2014-01-08

The ideal quantum gas dynamics as manifested by the semiclassical ellipsoidal-statistical (ES) equilibrium distribution derived in Wu et al. (Wu et al . 2012 Proc. R. Soc. A 468 , 1799-1823 (doi:10.1098/rspa.2011.0673)) is numerically studied for particles of three statistics. This anisotropic ES equilibrium distribution was derived using the maximum entropy principle and conserves the mass, momentum and energy, but differs from the standard Fermi-Dirac or Bose-Einstein distribution. The present numerical method combines the discrete velocity (or momentum) ordinate method in momentum space and the high-resolution shock-capturing method in physical space. A decoding procedure to obtain the necessary parameters for determining the ES distribution is also devised. Computations of two-dimensional Riemann problems are presented, and various contours of the quantities unique to this ES model are illustrated. The main flow features, such as shock waves, expansion waves and slip lines and their complex nonlinear interactions, are depicted and found to be consistent with existing calculations for a classical gas.

Numerical solutions of ideal quantum gas dynamical flows governed by semiclassical ellipsoidal-statistical distribution

PubMed Central

Yang, Jaw-Yen; Yan, Chih-Yuan; Diaz, Manuel; Huang, Juan-Chen; Li, Zhihui; Zhang, Hanxin

2014-01-01

The ideal quantum gas dynamics as manifested by the semiclassical ellipsoidal-statistical (ES) equilibrium distribution derived in Wu et al. (Wu et al. 2012 Proc. R. Soc. A 468, 1799–1823 (doi:10.1098/rspa.2011.0673)) is numerically studied for particles of three statistics. This anisotropic ES equilibrium distribution was derived using the maximum entropy principle and conserves the mass, momentum and energy, but differs from the standard Fermi–Dirac or Bose–Einstein distribution. The present numerical method combines the discrete velocity (or momentum) ordinate method in momentum space and the high-resolution shock-capturing method in physical space. A decoding procedure to obtain the necessary parameters for determining the ES distribution is also devised. Computations of two-dimensional Riemann problems are presented, and various contours of the quantities unique to this ES model are illustrated. The main flow features, such as shock waves, expansion waves and slip lines and their complex nonlinear interactions, are depicted and found to be consistent with existing calculations for a classical gas. PMID:24399919

Strong shock implosion, approximate solution

NASA Astrophysics Data System (ADS)

Fujimoto, Y.; Mishkin, E. A.; Alejaldre, C.

1983-01-01

The self-similar, center-bound motion of a strong spherical, or cylindrical, shock wave moving through an ideal gas with a constant, γ= cp/ cv, is considered and a linearized, approximate solution is derived. An X, Y phase plane of the self-similar solution is defined and the representative curved of the system behind the shock front is replaced by a straight line connecting the mappings of the shock front with that of its tail. The reduced pressure P(ξ), density R(ξ) and velocity U1(ξ) are found in closed, quite accurate, form. Comparison with numerically obtained results, for γ= {5}/{3} and γ= {7}/{5}, is shown.

Ideal cardiovascular health status and its association with socioeconomic factors in Chinese adults in Shandong, China.

PubMed

Ren, J; Guo, X L; Lu, Z L; Zhang, J Y; Tang, J L; Chen, X; Gao, C C; Xu, C X; Xu, A Q

2016-09-07

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the world. In 2010, a goal released by the American Heart Association (AHA) Committee focused on the primary reduction in cardiovascular risk. Data collected from 7683 men and 7667 women aged 18-69 years were analyzed. The distribution of ideal cardiovascular health metrics based on 7 cardiovascular disease risk factors or health behaviors in according to the definition of AHA was evaluated among the subjects. The association of the socioeconomic factors on the prevalence of meeting 5 or more ideal cardiovascular health metrics was estimated by logistic regression analysis, and a chi-square test for categorical variables and the general linear model (GLM) procedure for continuous variables were used to compare differences in prevalence and in means among genders. Seven of 15350 participants (0.05 %) met all 7 cardiovascular health metrics. The women had a higher proportion of meeting 5 or more ideal health metrics compared with men (32.67 VS.14.27 %). The subjects with a higher education and income level had a higher proportion of meeting 5 or more ideal health metrics than the subjects with a lower education and income level. A comparison between subjects with meeting 5 or more ideal cardiovascular health metrics with subjects meeting 4 or fewer ideal cardiovascular health metrics reveals that adjusted odds ratio [OR, 95 % confidence intervals (95 % CI)] was 1.42 (0.95, 2.21) in men and 2.59 (1.74, 3.87) in women for higher education and income, respectively. The prevalence of meeting all 7 cardiovascular health metrics was low in the adult population. Women, young subjects, and those with higher levels of education or income tend to have a greater number of the ideal cardiovascular health metrics. Higher socioeconomic status was associated with an increasing prevalence of meeting 5 or more cardiovascular health metrics in women but not in men. It's urgent to develop comprehensive

Promoting Spiritual Ideals through Design Thinking in Public Schools

ERIC Educational Resources Information Center

Tan, Charlene; Wong, Yew-Leong

2012-01-01

Against a backdrop of the debates on religious education in public or state schools, we argue for the introduction of "spiritual ideals" into the public school curriculum. We distinguish our notion of spiritual ideals from "religious ideals" as conceptualised by De Ruyter and Merry. While we agree with De Ruyter and Merry that…

Solution NMR Spectroscopy for the Study of Enzyme Allostery

PubMed Central

Lisi, George P.; Loria, J. Patrick

2016-01-01

Allostery is a ubiquitous biological regulatory process in which distant binding sites within a protein or enzyme are functionally and thermodynamically coupled. Allosteric interactions play essential roles in many enzymological mechanisms, often facilitating formation of enzyme-substrate complexes and/or product release. Thus, elucidating the forces that drive allostery is critical to understanding the complex transformations of biomolecules. Currently, a number of models exist to describe allosteric behavior, taking into account energetics as well as conformational rearrangements and fluctuations. In the following review, we discuss the use of solution NMR techniques designed to probe allosteric mechanisms in enzymes. NMR spectroscopy is unequaled in its ability to detect structural and dynamical changes in biomolecules, and the case studies presented herein demonstrate the range of insights to be gained from this valuable method. We also provide a detailed technical discussion of several specialized NMR experiments that are ideally suited for the study of enzymatic allostery. PMID:26734986

Study of the IGA/SCC behavior of Alloy 600 and 690 in high temperature solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsujikawa, S.; Yashima, S.; Ohnishi, K.

1995-09-01

IGA/SCC of Alloy 600 steam generator (SG) tubes in the secondary side has been recognized as a matter of great concern for PWRs. IGA/SCC behavior of Alloy 600 and 690 in high temperature solutions were studied using CERT method under potentiostatic conditions. The IGA/SCC susceptible regions were investigated as the function of pH and electrode potential. To understand the cause of IGA/SCC, the electrochemical measurements and surface film analysis were also performed in acidic and alkaline solutions. To verify the results of CERT test, the long term model boiler tests were also carried out. Thermally treated Alloy 690 showed highermore » IGA/SCC resistance than Alloy 600 under both acid and alkaline conditions.« less

Thermoresponsive Poly(Ionic Liquid)s in Aqueous Salt Solutions: Salting-Out Effect on Their Phase Behavior and Water Absorption/Desorption Properties.

PubMed

Okafuji, Akiyoshi; Kohno, Yuki; Ohno, Hiroyuki

2016-07-01

Here, a thermoresponsive phase behavior of polymerized ionic liquids (PILs) composed of poly([tri-n-alkyl(vinylbenzyl)phosphonium]chloride) (poly([Pnnn VB ]Cl) is reported, where n (the number of carbon atoms of an alkyl chain) = 4, 5, or 6 after mixing with aqueous sodium chloride solutions. Both monomeric [P555VB ]Cl and the resulting poly([P555VB ]Cl) linear homopolymer show a lower critical solution temperature (LCST)-type phase behavior in aq. NaCl solutions. The phase transition temperature of the PIL shifts to lower value by increasing concentration of NaCl. Also the swelling degree of cross-linked poly([P555VB ]Cl) gel decreases by increasing NaCl concentration, clearly suggesting the "salting-out" effect of NaCl results in a significant dehydration of the poly([P555VB ]Cl) gel. The absorbed water in the PIL gel is desorbed by moderate heating via the LCST behavior, and the absolute absorption/desorption amount is improved by copolymerization of [P555VB ]Cl with more hydrophilic [P444VB ]Cl monomer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Generic features of the wealth distribution in ideal-gas-like markets.

PubMed

Mohanty, P K

2006-07-01

We provide an exact solution to the ideal-gas-like models studied in econophysics to understand the microscopic origin of Pareto law. In these classes of models the key ingredient necessary for having a self-organized scale-free steady-state distribution is the trading or collision rule where agents or particles save a definite fraction of their wealth or energy and invest the rest for trading. Using a Gibbs ensemble approach we could obtain the exact distribution of wealth in this model. Moreover we show that in this model (a) good savers are always rich and (b) every agent poor or rich invests the same amount for trading. Nonlinear trading rules could alter the generic scenario observed here.

Behavior of GaSb (100) and InSb (100) surfaces in the presence of H2O2 in acidic and basic cleaning solutions

NASA Astrophysics Data System (ADS)

Seo, Dongwan; Na, Jihoon; Lee, Seunghyo; Lim, Sangwoo

2017-03-01

Gallium antimonide (GaSb) and indium antimonide (InSb) have attracted strong attention as new channel materials for transistors due to their excellent electrical properties and lattice matches with various group III-V compound semiconductors. In this study, the surface behavior of GaSb (100) and InSb (100) was investigated and compared in hydrochloric acid/hydrogen peroxide mixture (HPM) and ammonium hydroxide/hydrogen peroxide mixture (APM) solutions. In the acidic HPM solution, surface oxidation was greater and the etching rates of the GaSb and InSb surfaces increased when the solution is concentrated, which indicates that H2O2 plays a key role in the surface oxidation of GaSb and InSb in acidic HPM solution. However, the GaSb and InSb surfaces were hardly oxidized in basic APM solution in the presence of H2O2 because gallium and indium are in the thermodynamically stable forms of H2GaO3- and InO2-, respectively. When the APM solution was diluted, however, the Ga on the GaSb surface was oxidized by H2O, increasing the etching rate. However, the effect of dilution of the APM solution on the oxidation of the InSb surface was minimal; thus, the InSb surface was less oxidized than the GaSb surface and the change in the etching rate of InSb with dilution of the APM solution was not significant. Additionally, the oxidation behavior of gallium and indium was more sensitive to the composition of the HPM and APM solutions than that of antimony. Therefore, the surface properties and etching characteristics of GaSb and InSb in HPM and APM solutions are mainly dependent on the behavior of the group III elements rather than the group V elements.

On the union of graded prime ideals

NASA Astrophysics Data System (ADS)

Uregen, Rabia Nagehan; Tekir, Unsal; Hakan Oral, Kursat

2016-01-01

In this paper we investigate graded compactly packed rings, which is defined as; if any graded ideal I of R is contained in the union of a family of graded prime ideals of R, then I is actually contained in one of the graded prime ideals of the family. We give some characterizations of graded compactly packed rings. Further, we examine this property on h - Spec(R). We also define a generalization of graded compactly packed rings, the graded coprimely packed rings. We show that R is a graded compactly packed ring if and only if R is a graded coprimely packed ring whenever R be a graded integral domain and h - dim R = 1.

Solute-solvent cavity and bridge functions. I. Varying size of the solute

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyalov, I., E-mail: ivan.vyalov@iit.it; Chuev, G., E-mail: genchuev@rambler.ru; Georgi, N., E-mail: georgi@mis.mpg.de

2014-08-21

In this work we present the results of the extensive molecular simulations of solute-solvent cavity and bridge functions. The mixtures of Lennard-Jones solvent with Lennard-Jones solute at infinite dilution are considered for different solute-solvent size ratios—up to 4:1. The Percus-Yevick and hypernetted chain closures deviate substantially from simulation results in the investigated temperature and density ranges. We also find that the behavior of the indirect and cavity correlation functions is non-monotonous within the hard-core region, but the latter can be successfully approximated by mean-field theory if the solute-solvent interaction energy is divided into repulsive and attractive contribution, according to Weeks-Chandler-Andersenmore » theory. Furthermore, in spite of the non-monotonous behavior of logarithm of the cavity function and the indirect correlation function, their difference, i.e., the bridge function remains constant within the hard-core region. Such behavior of the bridge and indirect correlation functions at small distances and for small values of indirect correlation function is well known from the Duh-Haymet plots, where the non-unique relationship results in loops of the bridge function vs. indirect correlation function graphs. We show that the same pathological behavior appears also when distance is small and indirect correlation function is large. We further show that the unique functional behavior of the bridge function can be established when bridge is represented as a function of the renormalized, repulsive indirect correlation function.« less

Why Education in Public Schools Should Include Religious Ideals

ERIC Educational Resources Information Center

de Ruyter, Doret J.; Merry, Michael S.

2009-01-01

This article aims to open a new line of debate about religion in public schools by focusing on religious ideals. The article begins with an elucidation of the concept "religious ideals" and an explanation of the notion of reasonable pluralism, in order to be able to explore the dangers and positive contributions of religious ideals and their…

Optimal platform design using non-dominated sorting genetic algorithm II and technique for order of preference by similarity to ideal solution; application to automotive suspension system

NASA Astrophysics Data System (ADS)

Shojaeefard, Mohammad Hassan; Khalkhali, Abolfazl; Faghihian, Hamed; Dahmardeh, Masoud

2018-03-01

Unlike conventional approaches where optimization is performed on a unique component of a specific product, optimum design of a set of components for employing in a product family can cause significant reduction in costs. Increasing commonality and performance of the product platform simultaneously is a multi-objective optimization problem (MOP). Several optimization methods are reported to solve these MOPs. However, what is less discussed is how to find the trade-off points among the obtained non-dominated optimum points. This article investigates the optimal design of a product family using non-dominated sorting genetic algorithm II (NSGA-II) and proposes the employment of technique for order of preference by similarity to ideal solution (TOPSIS) method to find the trade-off points among the obtained non-dominated results while compromising all objective functions together. A case study for a family of suspension systems is presented, considering performance and commonality. The results indicate the effectiveness of the proposed method to obtain the trade-off points with the best possible performance while maximizing the common parts.

Idealization of the analyst by the young adult.

PubMed

Chused, J F

1987-01-01

Idealization is an intrapsychic process that serves many functions. In addition to its use defensively and for gratification of libidinal and aggressive drive derivatives, it can contribute to developmental progression, particularly during late adolescence and young adulthood. During an analysis, it is important to recognize all the determinants of idealization, including those related to the reworking of developmental conflicts. If an analyst understands idealization solely as a manifestation of pathology, he may interfere with his patient's use of it for the development of autonomous functioning.

Effects of Detergent β-Octylglucoside and Phosphate Salt Solutions on Phase Behavior of Monoolein Mesophases

PubMed Central

Khvostichenko, Daria S.; Ng, Johnathan J.D.; Perry, Sarah L.; Menon, Monisha; Kenis, Paul J.A.

2013-01-01

Using small-angle x-ray scattering (SAXS), we investigated the phase behavior of mesophases of monoolein (MO) mixed with additives commonly used for the crystallization of membrane proteins from lipidic mesophases. In particular, we examined the effect of sodium and potassium phosphate salts and the detergent β-octylglucoside (βOG) over a wide range of compositions relevant for the crystallization of membrane proteins in lipidic mesophases. We studied two types of systems: 1), ternary mixtures of MO with salt solutions above the hydration boundary; and 2), quaternary mixtures of MO with βOG and salt solutions over a wide range of hydration conditions. All quaternary mixtures showed highly regular lyotropic phase behavior with the same sequence of phases (Lα, Ia3d, and Pn3m) as MO/water mixtures at similar temperatures. The effects of additives in quaternary systems agreed qualitatively with those found in ternary mixtures in which only one additive is present. However, quantitative differences in the effects of additives on the lattice parameters of fully hydrated mesophases were found between ternary and quaternary mixtures. We discuss the implications of these findings for mechanistic investigations of membrane protein crystallization in lipidic mesophases and for studies of the suitability of precipitants for mesophase-based crystallization methods. PMID:24138861

Effect of amino acids on the eutectic behavior of NaCl solutions studied by DSC.

PubMed

Chen, N J; Morikawa, J; Hashimoto, T

2005-06-01

The effect of a series of amino acids on the eutectic behavior of NaCl solutions at isotonic concentration has been studied by differential scanning calorimetry. The inclusion of different amino acids had different effects on eutectic formation. The amino acids were grouped into four categories based on their effect on eutectic formation: category C were amino acids that had no effect on eutectic formation; category D amino acids inhibited eutectic formation; category T amino acids shifted the melting of the eutectic to a lower temperature; category E amino acids caused the formation of a new eutectic with a melting temperature approximately -5 degrees C. The mechanism of these different effects on eutectic behavior is discussed, based on the chemical structure of the amino acids.

Steady and dynamic shear rheological behavior of semi dilute Alyssum homolocarpum seed gum solutions: influence of concentration, temperature and heating-cooling rate.

PubMed

Alaeddini, Behzad; Koocheki, Arash; Mohammadzadeh Milani, Jafar; Razavi, Seyed Mohammad Ali; Ghanbarzadeh, Babak

2018-05-01

Alyssum homolocarpum seed gum (AHSG) solution exhibits high viscosity at low shear rates and has anionic features. However there is no information regarding the flow and dynamic properties of this gum in semi-dilute solutions. The present study aimed to investigate the dynamic and steady shear behavior of AHSG in the semi-dilute region. The viscosity profile demonestrated a shear thinning behavior at all temperatures and concentrations. An increase in the AHSG concentration was acompanied by an increase in the pseudoplasticity degree, whereas, by increasing the temperature, the pseudoplasticity of AHSG decreased. At low gum concentration, solutions had more viscosity dependence on temperature. The mechanical spectra obtained from the frequency sweep experiment demonstrated viscoelastic properties for gum solutions. AHSG solutions showed typical weak gel-like behavior, revealing G' greater than G' within the experimental range of frequency (Hz), with slight frequency dependency. The influence of temperature on viscoelastic properties of AHSG solutions was studied during both heating (5-85 °C) and cooling (85-5 °C) processes. The complex viscosity of AHSG was greater compared to the apparent viscosity, indicating the disruption of AHSG network structure under continuous shear rates and deviation from the Cox-Merz rule. During the initial heating, the storage modulus showed a decreasing trend and, with a further increase in temperature, the magnitude of storage modulus increased. The influence of temperature on the storage modulus was considerable when a higher heating rate was applied. AHSG can be applied as a thickening and stabilizing agents in food products that require good stability against temperature. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Single-solute and bisolute sorption of phenol and trichloroethylene from aqueous solution onto modified montmorillonite and application of sorption models.

PubMed

Wu, C D; Wang, L; Hu, C X; He, M H

2013-01-01

The single-solute and bisolute sorption behaviour of phenol and trichloroethylene, two organic compounds with different structures, onto cetyltrimethylammonium bromide (CTAB)-montmorillonite was studied. The monolayer Langmuir model (MLM) and empirical Freundlich model (EFM) were applied to the single-solute sorption of phenol or trichloroethylene from water onto monolayer or multilayer CTAB-montmorillonite. The parameters contained in the MLM and EFM were determined for each solute by fitting to the single-solute isotherm data, and subsequently utilized in binary sorption. The extended Langmuir model (ELM) coupled with the single-solute MLM and the ideal adsorbed solution theory (IAST) coupled with the single-solute EFM were used to predict the binary sorption of phenol and trichloroethylene onto CTAB-montmorillonite. It was found that the EFM was better than the MLM at describing single-solute sorption from water onto CTAB-montmorillonite, and the IAST was better than the ELM at describing the binary sorption from water onto CTAB-montmorillonite.

Young men's endorsement and pursuit of appearance ideals: The prospective role of appearance investment.

PubMed

Kling, Johanna; Rodgers, Rachel F; Frisén, Ann

2016-03-01

Appearance investment has been proposed as a risk factor for the development of body dissatisfaction. Despite this, few studies have explored men's investment in their appearance. The aim of the present study was therefore to examine appearance investment as a prospective predictor of young men's endorsement and pursuit of appearance ideals. A community sample of 187 young men participated in a study at ages 21 and 24. Hierarchical multiple regressions revealed that appearance investment, as hypothesized, was a prospective predictor of increases in leanness orientation, media-ideal internalization, and muscularity behaviors. However, appearance investment did not predict increases in muscularity dissatisfaction. The present findings highlight the importance of including appearance investment in sociocultural models of the development of men's body image, and suggest that appearance investment may be an important target variable to consider when designing body dissatisfaction prevention and intervention programs tailored to young men. Copyright © 2015 Elsevier Ltd. All rights reserved.

``Ideal glassformers'' vs ``ideal glasses'': Studies of crystal-free routes to the glassy state by ``potential tuning'' molecular dynamics, and laboratory calorimetry

NASA Astrophysics Data System (ADS)

Kapko, Vitaliy; Zhao, Zuofeng; Matyushov, Dmitry V.; Austen Angell, C.

2013-03-01

of "ideal glassformers" - single or multicomponent liquids that vitrify before ever becoming metastable with respect to crystals. We find evidence that "ideal glassformer" systems might also be highly fragile systems, approaching the "ideal glass" condition. We link this to the high "volume fragility" behavior observed in recent hard dumbbell studies at similar length/diameter ratios [R. Zhang and K. S. Schweitzer, J. Chem. Phys. 133, 104902 (2010), 10.1063/1.3483601]. The discussion suggests some unusual systems for laboratory study. Using differential scanning calorimetry detection of fusion points Tm, liquidus temperatures Tl, and glass transition temperatures Tg, we describe a system that would seem incapable of crystallizing before glass transition, i.e., an "ideal glassformer." The existence of crystal-free routes to the glassy state will eliminate precrystalline fluctuations as a source of the dynamic heterogeneities that are generally considered important in the discussion of the "glassy state problem [P. W. Anderson, Science 267, 1615 (1995), 10.1126/science.267.5204.1615-e]."

Analysis of Viking infrared thermal mapping data of Mars. The effects of non-ideal surfaces on the derived thermal properties of Mars

NASA Technical Reports Server (NTRS)

Muhleman, D. O.; Jakosky, B. M.

1979-01-01

The thermal interia of the surface of Mars varies spatially by a factor of eight. This is attributable to changes in the average particle size of the fine material, the surface elevation, the atmospheric opacity due to dust, and the fraction of the surface covered by rocks and fine material. The effects of these non-ideal properties on the surface temperatures and derived thermal inertias are modeled, along with the the effects of slopes, CO2 condensed onto the surface, and layering of fine material upon solid rock. The non-ideal models are capable of producing thermal behavior similar to that observed by the Viking Infrared Thermal Mapper, including a morning delay in the post-dawn temperature rise and an enhanced cooling in the afternoon relative to any ideal, homogeneous model. The enhanced afternoon cooling observed at the Viking-1 landing site is reproduced by the non-ideal models while that atop Arsia Mons volcano is not, but may be attributed to the observing geometry.

Moral identity as moral ideal self: links to adolescent outcomes.

PubMed

Hardy, Sam A; Walker, Lawrence J; Olsen, Joseph A; Woodbury, Ryan D; Hickman, Jacob R

2014-01-01

The purposes of this study were to conceptualize moral identity as moral ideal self, to develop a measure of this construct, to test for age and gender differences, to examine links between moral ideal self and adolescent outcomes, and to assess purpose and social responsibility as mediators of the relations between moral ideal self and outcomes. Data came from a local school sample (Data Set 1: N = 510 adolescents; 10-18 years of age) and a national online sample (Data Set 2: N = 383 adolescents; 15-18 years of age) of adolescents and their parents. All outcome measures were parent-report (Data Set 1: altruism, moral personality, aggression, and cheating; Data Set 2: environmentalism, school engagement, internalizing, and externalizing), whereas other variables were adolescent-report. The 20-item Moral Ideal Self Scale showed good reliability, factor structure, and validity. Structural equation models demonstrated that, even after accounting for moral identity internalization, in Data Set 1 moral ideal self positively predicted altruism and moral personality and negatively predicted aggression, whereas in Data Set 2 moral ideal self positively predicted environmentalism and negatively predicted internalizing and externalizing symptoms. Further, purpose and social responsibility mediated most relations between moral ideal self and the outcomes in Data Set 2. Moral ideal self was unrelated to age but differentially predicted some outcomes across age. Girls had higher levels of moral ideal self than boys, although moral identity did not differentially predict outcomes between genders. Thus, moral ideal self is a salient element of moral identity and may play a role in morally relevant adolescent outcomes. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Mutual Influence of Mannitol and Trehalose on Crystallization Behavior in Frozen Solutions.

PubMed

Jena, Sampreeti; Suryanarayanan, Raj; Aksan, Alptekin

2016-06-01

Phase separation of trehalose during freeze-drying could render it ineffective as a lyoprotectant. The bulking agent, mannitol, on the other hand, should crystallize readily upon freezing. It is therefore imperative to understand the mutual interaction of these sugars during freezing to ensure preservation of the API during freeze-drying. We investigated the effect of mannitol to trehalose ratio (R) on the crystallization behavior of both solutes using Differential Scanning Calorimetry, X-Ray Crystallography and FTIR Spectrosopy during controlled freezing and annealing. When R = 1, crystallization of both mannitol (as hemihydrate) and trehalose (as α-anhydrate) were observed. When R ≥ 1, extent of mannitol crystallization was directly proportional to the value of R. When R < 1, trehalose completely suppressed mannitol crystallization. At R > 1, the freeze concentrate was heterogeneous and characterized by two glass transitions - the lower temperature transition (Tg") attributed to systems containing "extra" unfrozen water. When heated above Tg", crystallization of mannitol and the associated unfrozen water resulted in Tg' (glass transition temperature of the freeze-concentrate). R and not the total solute concentration, dictates the composition of the freeze concentrate as well as the physical stability of the excipients.

Desorption behavior of sorbed flavor compounds from packaging films with ethanol solution.

PubMed

Hwang, Y H; Matsui, T; Hanada, T; Shimoda, M; Matsumoto, K; Osajima, Y

2000-09-01

Desorption behavior of sorbed flavor compounds such as ethyl esters, n-aldehydes, and n-alcohols from LDPE and PET films was investigated in 0 to 100% (v/v) ethanol solutions at 20 degrees C, 50 degrees C, and 60 degrees C. In both films, the desorption apparently increased with increasing ethanol concentration and treatment temperature, depending on the compatibility of the flavor compound with the solvent. Namely, the partition coefficient of ethyl esters, n-aldehydes, and n-alcohols in the LDPE film turned out to be approximately zero at >/=60%, >/=80%, and >/=40% (v/v) ethanol, respectively (for PET film, >/=80%, >/=80%, and >/=40% (v/v) ethanol concentrations were required for complete desorption, respectively). As for physical properties (heat of fusion, melting point, and tensile strength and elongation at break) of LDPE and PET films, there were no significant differences between intact film and the treated film with 60% (v/v) ethanol for 30 min at 60 degrees C. These results suggest that it is possible to apply a desorption solvent such as ethanol solution for desorption of sorbed flavor compounds from packaging films with no physical change in the film properties by this desorption treatment.

Using a tracer technique to identify the extent of non-ideal flows in the continuous mixing of non-Newtonian fluids

NASA Astrophysics Data System (ADS)

Patel, D.; Ein-Mozaffari, F.; Mehrvar, M.

2013-05-01

The identification of non-ideal flows in a continuous-flow mixing of non-Newtonian fluids is a challenging task for various chemical industries: plastic manufacturing, water and wastewater treatment, and pulp and paper manufacturing. Non-ideal flows such as channelling, recirculation, and dead zones significantly affect the performance of continuous-flow mixing systems. Therefore, the main objective of this paper was to develop an identification protocol to measure non-ideal flows in the continuous-flow mixing system. The extent of non-ideal flows was quantified using a dynamic model that incorporated channelling, recirculation, and dead volume in the mixing vessel. To estimate the dynamic model parameters, the system was excited using a frequency-modulated random binary input by injecting the saline solution (as a tracer) into the fresh feed stream prior to being pumped into the mixing vessel. The injection of the tracer was controlled by a computer-controlled on-off solenoid valve. Using the trace technique, the extent of channelling and the effective mixed volume were successfully determined and used as mixing quality criteria. Such identification procedures can be applied at various areas of chemical engineering in order to improve the mixing quality.

Direct NMR Monitoring of Phase Separation Behavior of Highly Supersaturated Nifedipine Solution Stabilized with Hypromellose Derivatives.

PubMed

Ueda, Keisuke; Higashi, Kenjirou; Moribe, Kunikazu

2017-07-03

We investigated the phase separation behavior and maintenance mechanism of the supersaturated state of poorly water-soluble nifedipine (NIF) in hypromellose (HPMC) derivative solutions. Highly supersaturated NIF formed NIF-rich nanodroplets through phase separation from aqueous solution containing HPMC derivative. Dissolvable NIF concentration in the bulk water phase was limited by the phase separation of NIF from the aqueous solution. HPMC derivatives stabilized the NIF-rich nanodroplets and maintained the NIF supersaturation with phase-separated NIF for several hours. The size of the NIF-rich phase was different depending on the HPMC derivatives dissolved in aqueous solution, although the droplet size had no correlation with the time for which NIF supersaturation was maintained without NIF crystallization. HPMC acetate and HPMC acetate succinate (HPMC-AS) effectively maintained the NIF supersaturation containing phase-separated NIF compared with HPMC. Furthermore, HPMC-AS stabilized NIF supersaturation more effectively in acidic conditions. Solution 1 H NMR measurements of NIF-supersaturated solution revealed that HPMC derivatives distributed into the NIF-rich phase during the phase separation of NIF from the aqueous solution. The hydrophobicity of HPMC derivative strongly affected its distribution into the NIF-rich phase. Moreover, the distribution of HPMC-AS into the NIF-rich phase was promoted at lower pH due to the lower aqueous solubility of HPMC-AS. The distribution of a large amount of HPMC derivatives into NIF-rich phase induced the strong inhibition of NIF crystallization from the NIF-rich phase. Polymer distribution into the drug-rich phase directly monitored by solution NMR technique can be a useful index for the stabilization efficiency of drug-supersaturated solution containing a drug-rich phase.

Dynamical Approach Study of Spurious Steady-State Numerical Solutions of Nonlinear Differential Equations. Part 2; Global Asymptotic Behavior of Time Discretizations

NASA Technical Reports Server (NTRS)

Yee, H. C.; Sweby, P. K.

1995-01-01

The global asymptotic nonlinear behavior of 11 explicit and implicit time discretizations for four 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODEs) is analyzed. The objectives are to gain a basic understanding of the difference in the dynamics of numerics between the scalars and systems of nonlinear autonomous ODEs and to set a baseline global asymptotic solution behavior of these schemes for practical computations in computational fluid dynamics. We show how 'numerical' basins of attraction can complement the bifurcation diagrams in gaining more detailed global asymptotic behavior of time discretizations for nonlinear differential equations (DEs). We show how in the presence of spurious asymptotes the basins of the true stable steady states can be segmented by the basins of the spurious stable and unstable asymptotes. One major consequence of this phenomenon which is not commonly known is that this spurious behavior can result in a dramatic distortion and, in most cases, a dramatic shrinkage and segmentation of the basin of attraction of the true solution for finite time steps. Such distortion, shrinkage and segmentation of the numerical basins of attraction will occur regardless of the stability of the spurious asymptotes, and will occur for unconditionally stable implicit linear multistep methods. In other words, for the same (common) steady-state solution the associated basin of attraction of the DE might be very different from the discretized counterparts and the numerical basin of attraction can be very different from numerical method to numerical method. The results can be used as an explanation for possible causes of error, and slow convergence and nonconvergence of steady-state numerical solutions when using the time-dependent approach for nonlinear hyperbolic or parabolic PDEs.

The realities of idealism.

PubMed

Roslyn, J J

1993-04-01

I started out asking the question can we achieve our goals and are our goals realistic in the 1990s? I believe that we can achieve anything that we set our minds to. Our goals of providing quality care to our patients, performing research, teaching the next generation, and having an impact on our local environment are worth pursuing. However, the rules have changed and the status quo is simply not good enough. If we are to survive, we must be prepared for the future. You have the ability to change and the power to control the future. You are the future. Seize the opportunity and get involved. Become knowledgeable about health care economics, become involved with the political process, and position yourselves so that you can be a part of the solution to our health care system's woes. Don't allow the moment to pass. Don't be afraid of the realities of today, and don't forget your ideals and principles. Confront today's challenges with the same determination that academic surgeons through the years have confronted the unknown mysteries of disease. Let me conclude by trying to synthesize my remarks in five generic recommendations: 1. We need to go forward in the research area by developing multidisciplinary programs that involve basic science. These programs can be used to highlight our clinical areas and expertise. In this manner, both areas will be benefitted. 2. We need to educate the public and the government about the virtues of research and the importance of maintaining academic surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Electronic Health Record Challenges, Workarounds, and Solutions Observed in Practices Integrating Behavioral Health and Primary Care.

PubMed

Cifuentes, Maribel; Davis, Melinda; Fernald, Doug; Gunn, Rose; Dickinson, Perry; Cohen, Deborah J

2015-01-01

This article describes the electronic health record (EHR)-related experiences of practices striving to integrate behavioral health and primary care using tailored, evidenced-based strategies from 2012 to 2014; and the challenges, workarounds and initial health information technology (HIT) solutions that emerged during implementation. This was an observational, cross-case comparative study of 11 diverse practices, including 8 primary care clinics and 3 community mental health centers focused on the implementation of integrated care. Practice characteristics (eg, practice ownership, federal designation, geographic area, provider composition, EHR system, and patient panel characteristics) were collected using a practice information survey and analyzed to report descriptive information. A multidisciplinary team used a grounded theory approach to analyze program documents, field notes from practice observation visits, online diaries, and semistructured interviews. Eight primary care practices used a single EHR and 3 practices used 2 different EHRs, 1 to document behavioral health and 1 to document primary care information. Practices experienced common challenges with their EHRs' capabilities to 1) document and track relevant behavioral health and physical health information, 2) support communication and coordination of care among integrated teams, and 3) exchange information with tablet devices and other EHRs. Practices developed workarounds in response to these challenges: double documentation and duplicate data entry, scanning and transporting documents, reliance on patient or clinician recall for inaccessible EHR information, and use of freestanding tracking systems. As practices gained experience with integration, they began to move beyond workarounds to more permanent HIT solutions ranging in complexity from customized EHR templates, EHR upgrades, and unified EHRs. Integrating behavioral health and primary care further burdens EHRs. Vendors, in cooperation with

[Challenges and risks in the development of the ego ideal in adolescence].

PubMed

Helbing-Tietze, Brigitte

2003-11-01

The author proposes to speak of representations concerning the ideal self, the ideal relationship, the ideal society instead of ego ideal. An active self develops ideals and uses them as standards for orientation, to regulate the affects, and to fulfill needs. The different ideals often do not fit together and are therefore difficult to realize. Adolescents normally refuse their parents' ideals and create new ones with the help of their peers. This developmental step is full of challenges and risks as will be explained in this article.

Justifying an ideal first pregnancy age: Vernacular science knowledge and the facilitation of lay argument.

PubMed

Jensen, Robin E; Blumling, Allison N

2018-04-01

Members of the lay public often draw from vernacular science knowledge-or metaphors, images, and terms related to technical science-to make normative assessments about behavior. Yet, little is known about vernacular science knowledge in terms of its forms and functions. In a national survey, US adults ( N = 688) were asked to identify an ideal age for first pregnancy, and to explain their decision. Participants drew from arguments related to hormonal processes, the language of risk, and the quality and quantity of "eggs" to navigate and identify an ideal timeline for first pregnancy. Their responses illustrated patterns of justification that involved the (a) employment of scientific concepts as heuristic cues for critical analysis, (b) conflation of details, and (c) synecdochal explication. These findings reveal some of the key ways in which vernacular science knowledge may shape the trajectory of lay argument in a range of contexts.

Perceived and Ideal Body Image in Young Women in South Western Saudi Arabia.

PubMed

Khalaf, Atika; Westergren, Albert; Berggren, Vanja; Ekblom, Örjan; Al-Hazzaa, Hazzaa M

2015-01-01

The aim of this study was to investigate perceived and ideal body image (BI) and associated factors among female university students in Saudi Arabia. This cross-sectional study included 663 university female students. Anthropometric measurements including weight, height, BMI, and BI perception (the 9-figure silhouette) were obtained. Descriptive and logistic regression analysis were conducted. An agreement between actual, perceived, and ideal BI was found in 23% of the participants. Behavioral (activity levels), social (presence of obese parents and fathers' level of education), and economic factors (households' monthly income, number of cars in the household, and kind of residence) were positively and significantly associated with the desire to be thinner. Similarly, socioeconomic associations (number of sisters and number of cars in the household) correlated positively and significantly with the desire to be heavier. The whole family should rather be considered in interventions related to appearance concerns and BI discrepancies. Furthermore, campaigns targeting improvement of adolescents' physical self-image should be a major priority of the public health sector.

The ideal subject distance for passport pictures.

PubMed

Verhoff, Marcel A; Witzel, Carsten; Kreutz, Kerstin; Ramsthaler, Frank

2008-07-04

In an age of global combat against terrorism, the recognition and identification of people on document images is of increasing significance. Experiments and calculations have shown that the camera-to-subject distance - not the focal length of the lens - can have a significant effect on facial proportions. Modern passport pictures should be able to function as a reference image for automatic and manual picture comparisons. This requires a defined subject distance. It is completely unclear which subject distance, in the taking of passport photographs, is ideal for the recognition of the actual person. We show here that the camera-to-subject distance that is perceived as ideal is dependent on the face being photographed, even if the distance of 2m was most frequently preferred. So far the problem of the ideal camera-to-subject distance for faces has only been approached through technical calculations. We have, for the first time, answered this question experimentally with a double-blind experiment. Even if there is apparently no ideal camera-to-subject distance valid for every face, 2m can be proposed as ideal for the taking of passport pictures. The first step would actually be the determination of a camera-to-subject distance for the taking of passport pictures within the standards. From an anthropological point of view it would be interesting to find out which facial features allow the preference of a shorter camera-to-subject distance and which allow the preference of a longer camera-to-subject distance.

Electrochemical Behavior of Pure Copper in Phosphate Buffer Solutions: A Comparison Between Micro- and Nano-Grained Copper

NASA Astrophysics Data System (ADS)

Imantalab, O.; Fattah-alhosseini, A.; Keshavarz, M. K.; Mazaheri, Y.

2016-02-01

In this work, electrochemical behavior of annealed (micro-) and nano-grained pure copper (fabricated by accumulative roll bonding process) in phosphate buffer solutions of various pH values ranging from 10.69 to 12.59 has been studied. Before any electrochemical measurements, evaluation of microstructure was obtained by optical microscope and transmission electron microscopy. To investigate the electrochemical behavior of the samples, the potentiodynamic polarization, Mott-Schottky analysis, and electrochemical impedance spectroscopy (EIS) were carried out. Potentiodynamic polarization plots and EIS measurements revealed that as a result of grain refinement, the passive behavior of the nano-grained sample was improved compared to that of annealed pure copper. Also, Mott-Schottky analysis indicated that the passive films behaved as p-type semiconductors and grain refinement did not change the semiconductor type of passive films.

Spaces of ideal convergent sequences.

PubMed

Mursaleen, M; Sharma, Sunil K

2014-01-01

In the present paper, we introduce some sequence spaces using ideal convergence and Musielak-Orlicz function ℳ = (M(k)). We also examine some topological properties of the resulting sequence spaces.

Solution properties of almandine-pyrope garnet as determined by phase equilibrium experiments

USGS Publications Warehouse

Koziol, A.M.; Bohlen, S.R.

1992-01-01

The thermodynamic mixing properties of almandine-pyrope garnet were derived from phase equilibrium experiments at temperatures of 900 and 1000??C and pressures from 8 to 14 kbar. Almandine has essentially ideal behavior in almandine-pyrope garnet over the composition range Alm89-Alm61 at the above experimental conditions. In all experimental products a systematic partitioning of Fe and Mg between garnet and ilmenite was seen with ln Kd ??? 1.59 which was not temperature sensitive. The results support the use of garnet mixing models that incorporate ideal or nearly ideal Fe-Mg parameters. -from Authors

Exact solution for spin precession in the radiationless relativistic Kepler problem

NASA Astrophysics Data System (ADS)

Mane, S. R.

2014-11-01

There is interest in circulating beams of polarized particles in all-electric storage rings to search for nonzero permanent electric dipole moments of subatomic particles. To this end, it is helpful to derive exact analytical solutions of the spin precession in idealized models, both for pedagogical reasons and to serve as benchmark tests for analysis and design of experiments. This paper derives exact solutions for the spin precession in the relativistic Kepler problem. Some counterintuitive properties of the solutions are pointed out.

Media-portrayed idealized images, body shame, and appearance anxiety.

PubMed

Monro, Fiona; Huon, Gail

2005-07-01

This study was designed to determine the effects of media-portrayed idealized images on young women's body shame and appearance anxiety, and to establish whether the effects depend on advertisement type and on participant self-objectification. Participants were 39 female university students. Twenty-four magazine advertisements comprised 12 body-related and 12 non-body-related products, one half of each with, and the other one half without, idealized images. Preexposure and post exposure body shame and appearance anxiety measures were recorded. Appearance anxiety increased after viewing advertisements featuring idealized images. There was also a significant interaction between self-objectification level and idealized body (presence vs. absence). No differences emerged for body-related compared with non-body-related product advertisements. The only result for body shame was a main effect for time. Participants' body shame increased after exposure to idealized images, irrespective of advertisement type. Although our findings reveal that media-portrayed idealized images detrimentally affect the body image of young women, they highlight the individual differences in vulnerability and the different effects for different components of body image. These results are discussed in terms of their implications for the prevention and early intervention of body image and dieting-related disorders. ( Copyright 2005 by Wiley Periodicals, Inc

Oscillatory conductive heat transfer for a fiber in an ideal gas

NASA Technical Reports Server (NTRS)

Kuntz, H. L.; Perreira, N. D.

1985-01-01

A description of the thermal effects created by placing a cylindrical fiber in an inviscid, ideal gas, through which an acoustic wave propagates, is presented. The fibers and the gas have finite heat capacities and thermal conductivities. Expressions for the temperature distribution in the gas and in the material are determined. The temperature distribution is caused by pressure oscillations in the gas which, in turn, are caused by the passage of an acoustic wave. The relative value of a dimensionless parameter is found to be indicative of whether the exact or approximate equations should be used in the solution. This parameter is a function of the thermal conductivities and heat capacities of the fiber and gas, the acoustic frequency, and the fiber diameter.

Coupling Ideality of Integrated Planar High-Q Microresonators

NASA Astrophysics Data System (ADS)

Pfeiffer, Martin H. P.; Liu, Junqiu; Geiselmann, Michael; Kippenberg, Tobias J.

2017-02-01

Chip-scale optical microresonators with integrated planar optical waveguides are useful building blocks for linear, nonlinear, and quantum-optical photonic devices alike. Loss reduction through improving fabrication processes results in several integrated microresonator platforms attaining quality (Q ) factors of several millions. Beyond the improvement of the quality factor, the ability to operate the microresonator with high coupling ideality in the overcoupled regime is of central importance. In this regime, the dominant source of loss constitutes the coupling to a single desired output channel, which is particularly important not only for quantum-optical applications such as the generation of squeezed light and correlated photon pairs but also for linear and nonlinear photonics. However, to date, the coupling ideality in integrated photonic microresonators is not well understood, in particular, design-dependent losses and their impact on the regime of high ideality. Here we investigate design-dependent parasitic losses described by the coupling ideality of the commonly employed microresonator design consisting of a microring-resonator waveguide side coupled to a straight bus waveguide, a system which is not properly described by the conventional input-output theory of open systems due to the presence of higher-order modes. By systematic characterization of multimode high-Q silicon nitride microresonator devices, we show that this design can suffer from low coupling ideality. By performing 3D simulations, we identify the coupling to higher-order bus waveguide modes as the dominant origin of parasitic losses which lead to the low coupling ideality. Using suitably designed bus waveguides, parasitic losses are mitigated with a nearly unity ideality and strong overcoupling (i.e., a ratio of external coupling to internal resonator loss rate >9 ) are demonstrated. Moreover, we find that different resonator modes can exchange power through the coupler, which, therefore

The effect of solution nonideality on modeling transmembrane water transport and diffusion-limited intracellular ice formation during cryopreservation

NASA Astrophysics Data System (ADS)

Zhao, Gang; Takamatsu, Hiroshi; He, Xiaoming

2014-04-01

A new model was developed to predict transmembrane water transport and diffusion-limited ice formation in cells during freezing without the ideal-solution assumption that has been used in previous models. The model was applied to predict cell dehydration and intracellular ice formation (IIF) during cryopreservation of mouse oocytes and bovine carotid artery endothelial cells in aqueous sodium chloride (NaCl) solution with glycerol as the cryoprotectant or cryoprotective agent. A comparison of the predictions between the present model and the previously reported models indicated that the ideal-solution assumption results in under-prediction of the amount of intracellular ice at slow cooling rates (<50 K/min). In addition, the lower critical cooling rates for IIF that is lethal to cells predicted by the present model were much lower than those estimated with the ideal-solution assumption. This study represents the first investigation on how accounting for solution nonideality in modeling water transport across the cell membrane could affect the prediction of diffusion-limited ice formation in biological cells during freezing. Future studies are warranted to look at other assumptions alongside nonideality to further develop the model as a useful tool for optimizing the protocol of cell cryopreservation for practical applications.

The effect of solution nonideality on modeling transmembrane water transport and diffusion-limited intracellular ice formation during cryopreservation.

PubMed

Zhao, Gang; Takamatsu, Hiroshi; He, Xiaoming

2014-04-14

A new model was developed to predict transmembrane water transport and diffusion-limited ice formation in cells during freezing without the ideal-solution assumption that has been used in previous models. The model was applied to predict cell dehydration and intracellular ice formation (IIF) during cryopreservation of mouse oocytes and bovine carotid artery endothelial cells in aqueous sodium chloride (NaCl) solution with glycerol as the cryoprotectant or cryoprotective agent. A comparison of the predictions between the present model and the previously reported models indicated that the ideal-solution assumption results in under-prediction of the amount of intracellular ice at slow cooling rates (<50 K/min). In addition, the lower critical cooling rates for IIF that is lethal to cells predicted by the present model were much lower than those estimated with the ideal-solution assumption. This study represents the first investigation on how accounting for solution nonideality in modeling water transport across the cell membrane could affect the prediction of diffusion-limited ice formation in biological cells during freezing. Future studies are warranted to look at other assumptions alongside nonideality to further develop the model as a useful tool for optimizing the protocol of cell cryopreservation for practical applications.

Dissipative MHD solutions for resonant Alfven waves in 1-dimensional magnetic flux tubes

NASA Technical Reports Server (NTRS)

Goossens, Marcel; Ruderman, Michail S.; Hollweg, Joseph V.

1995-01-01

The present paper extends the analysis by Sakurai, Goossens, and Hollweg (1991) on resonant Alfven waves in nonuniform magnetic flux tubes. It proves that the fundamental conservation law for resonant Alfven waves found in ideal MHD by Sakurai, Goossens, and Hollweg remains valid in dissipative MHD. This guarantees that the jump conditions of Sakurai, Goossens, and Hollweg, that connect the ideal MHD solutions for xi(sub r), and P' across the dissipative layer, are correct. In addition, the present paper replaces the complicated dissipative MHD solutions obtained by Sakurai, Goossens, and Hollweg for xi(sub r), and P' in terms of double integrals of Hankel functions of complex argument of order 1/3 with compact analytical solutions that allow a straight- forward mathematical and physical interpretation. Finally, it presents an analytical dissipative MHD solution for the component of the Lagrangian displacement in the magnetic surfaces perpen- dicular to the magnetic field lines xi(sub perpendicular) which enables us to determine the dominant dynamics of resonant Alfven waves in dissipative MHD.

Incentives to create and sustain healthy behaviors: technology solutions and research needs.

PubMed

Teyhen, Deydre S; Aldag, Matt; Centola, Damon; Edinborough, Elton; Ghannadian, Jason D; Haught, Andrea; Jackson, Theresa; Kinn, Julie; Kunkler, Kevin J; Levine, Betty; Martindale, Valerie E; Neal, David; Snyder, Leslie B; Styn, Mindi A; Thorndike, Frances; Trabosh, Valerie; Parramore, David J

2014-12-01

Health-related technology, its relevance, and its availability are rapidly evolving. Technology offers great potential to minimize and/or mitigate barriers associated with achieving optimal health, performance, and readiness. In support of the U.S. Army Surgeon General's vision for a "System for Health" and its Performance Triad initiative, the U.S. Army Telemedicine and Advanced Technology Research Center hosted a workshop in April 2013 titled "Incentives to Create and Sustain Change for Health." Members of government and academia participated to identify and define the opportunities, gain clarity in leading practices and research gaps, and articulate the characteristics of future technology solutions to create and sustain real change in the health of individuals, the Army, and the nation. The key factors discussed included (1) public health messaging, (2) changing health habits and the environmental influence on health, (3) goal setting and tracking, (4) the role of incentives in behavior change intervention, and (5) the role of peer and social networks in change. This report summarizes the recommendations on how technology solutions could be employed to leverage evidence-based best practices and identifies gaps in research where further investigation is needed. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

Sharp Truncation of an Electric Field: An Idealized Model that Warrants Caution

NASA Astrophysics Data System (ADS)

Tu, Hong; Zhu, Jiongming

2016-03-01

In physics, idealized models are often used to simplify complex situations. The motivation of the idealization is to make the real complex system tractable by adopting certain simplifications. In this treatment some unnecessary, negligible aspects are stripped away (so-called Aristotelian idealization), or some deliberate distortions are involved (so-called Galilean idealization). The most important principle in using an idealized model is to make sure that all the neglected aspects do not affect our analysis or result. Point charges, rigid bodies, simple pendulums, frictionless planes, and isolated systems are all frequently used idealized models. However, when they are applied to certain uncommon models, extra precautions should be taken. The possibilities and necessities of adopting the idealizations have to be considered carefully. Sometimes some factors neglected or ignored in the idealization could completely change the result, even make the treatment unphysical and conclusions unscientific.

Effect of Ge surface termination on oxidation behavior

NASA Astrophysics Data System (ADS)

Lee, Younghwan; Park, Kibyung; Cho, Yong Soo; Lim, Sangwoo

2008-09-01

Sulfur-termination was formed on the Ge(1 0 0) surface using (NH 4) 2S solution. Formation of Ge-S and the oxidation of the S-terminated Ge surface were monitored with multiple internal reflection Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. In the 0.5, 5, or 20% (NH 4) 2S solution, H-termination on the Ge(1 0 0) surface was substituted with S-termination in 1 min. When the S-terminated Ge(1 0 0) surface was exposed in air ambient, the oxidation was retarded for about 3600 min. The preservation time of the oxide layer up to one monolayer of S-terminated Ge(1 0 0) surface was about 120 times longer than for the H-terminated Ge(1 0 0) surface. However, the oxidation of S-terminated Ge(1 0 0) surface drastically increased after the threshold time. There was no significant difference in threshold time between S-terminations formed in 0.5, 5, and 20% (NH 4) 2S solutions. With the surface oxidation, desorption of S on the Ge surface was observed. The desorption behavior of sulfur on the S-terminated Ge(1 0 0) surface was independent of the concentration of the (NH 4) 2S solution that forms S-termination. Non-ideal S-termination on Ge surfaces may be related to drastic oxidation of the Ge surface. Finally, with the desulfurization on the S-terminated Ge(1 0 0) surface, oxide growth is accelerated.

Effect of Ternary Solutes on the Evolution of Structure and Gel Formation in Amphiphilic Copolymer Solutions

NASA Astrophysics Data System (ADS)

Meznarich, Norman Anthony Kang

Aqueous solutions of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) amphiphilic triblock copolymers (commercially known as Pluronic surfactants) undergo reversible and temperature-dependent micellization and arrangement into cubic ordered lattices known as "micelle gels". The macroscopic behavior of the ordering is a transition from a liquid to a gel. While the phase behavior and gel structure of pure Pluronic surfactant solutions have been well studied, less is known about the effects of added ternary solutes. In this dissertation, a comprehensive investigation into the effects of the added pharmaceutical methylparaben on solutions of F127 ranging from 10 to 30 wt% was conducted in order to better understand the behavior of F127 in multicomponent pharmaceutical formulations. The viscoelastic properties of F127 gel formation were studied using rheometry, where heating rates of 0.1, 1, and 10 degrees C/min were also used to probe the kinetics of the gel transition. In solutions containing methylparaben, F127 gelation occurred at up to 15 degrees C lower temperatures and was accelerated by a factor of three to four. Small angle x-ray scattering (SAXS) was used to characterize the structure of the ordered domains, and how they were affected by the presence of dissolved pharmaceuticals. It was found that ordered domain formation changed from heterogeneous nucleation and growth to possible homogeneous nucleation and growth. A roughly 2% reduction in the cubic lattice parameter was also observed for solutions containing methylparaben. Differential scanning calorimetry (DSC) experiments were performed on a series of different Pluronic surfactants in order to characterize the micellization behavior as a function of PPO center block length and PEO/PPO ratio. Added methylparaben suppressed the micellization endotherm, the degree of suppression depending linearly on the amount of added methylparaben, as well as the length of the PPO center block and PEO

The Dual Role of Media Internalization in Adolescent Sexual Behavior.

PubMed

Rousseau, Ann; Beyens, Ine; Eggermont, Steven; Vandenbosch, Laura

2017-08-01

Sexualizing media content is prevalent in various media types. Sexualizing media messages and portrayals emphasize unattainable body and appearance ideals as the primary components of sexual desirability. The internalization of these ideals is positively related to self-objectification and sexual body consciousness. In turn, self-objectification and sexual body consciousness affect adolescents' sexual behavior, albeit in opposing directions. While objectifying self-perceptions are linked to higher levels of sexual behavior, body consciousness during physical intimacy is linked to lower levels of sexual behavior. Based on this knowledge, the present three-wave panel study of 824 Belgian, predominant heterosexual adolescents (M age  = 15.33; SD = 1.45) proposes a dual-pathway model that investigates two different pathways through which the internalization of media ideals may impact adolescents' sexual behavior. An inhibitory pathway links media internalization to lower levels of sexual behavior through sexual body consciousness, and a supportive pathway links media internalization to higher levels of sexual behavior through self-objectification. Structural equation analyses supported the proposed dual-pathway, showing that the impact of media internalization on adolescents' sexual behavior proceeds through an inhibitory pathway and a supportive pathway. Regarding the supportive pathway, media internalization (W1) positively predicted sexual behavior (W3), through valuing appearance over competence (W2). Regarding the inhibitory pathway, media internalization (W1) positively predicted body surveillance, which, in turn, positively predicted sexual body consciousness (all W2). Sexual body consciousness (W2) is negatively related to sexual behavior (W3). From a sexual developmental perspective, these findings emphasize the importance of guiding adolescents in interpreting and processing sexualizing media messages.

Ideal thermodynamic processes of oscillatory-flow regenerative engines will go to ideal stirling cycle?

NASA Astrophysics Data System (ADS)

Luo, Ercang

2012-06-01

This paper analyzes the thermodynamic cycle of oscillating-flow regenerative machines. Unlike the classical analysis of thermodynamic textbooks, the assumptions for pistons' movement limitations are not needed and only ideal flowing and heat transfer should be maintained in our present analysis. Under such simple assumptions, the meso-scale thermodynamic cycles of each gas parcel in typical locations of a regenerator are analyzed. It is observed that the gas parcels in the regenerator undergo Lorentz cycle in different temperature levels, whereas the locus of all gas parcels inside the regenerator is the Ericson-like thermodynamic cycle. Based on this new finding, the author argued that ideal oscillating-flow machines without heat transfer and flowing losses is not the Stirling cycle. However, this new thermodynamic cycle can still achieve the same efficiency of the Carnot heat engine and can be considered a new reversible thermodynamic cycle under two constant-temperature heat sinks.

Corrosion Behavior of Magnesium Based Foam Structure in Hank’s Solution

NASA Astrophysics Data System (ADS)

Franciska, P. L.; Erryani, A.; Annur, D.; Kartika, I.

2017-05-01

Metal foam is a new class of materials with promising applications and a unique combination of physical, chemical, and mechanical properties. The purpose of biodegradable implants is to support tissue regeneration and healing in a particular application by material degradation and implant replacement through the surrounding tissue. Magnesium alloys are expected to be degraded in the body and its corrosion products not deleterious to the surrounding tissue. In the present study, the foam metal was manufactured via powder metallurgy with a different variation of sintering temperature and TiH2 used as a foaming agent which are added to Mg-1Ca-3Zn alloy as much 3% wt TiH2. The sintering temperatures were 500, 550 and 600 °C with a constant holding time of 5 hours. It’s critical that the sintering temperature is carefully selected in consideration of their corrosion behavior. This paper reports the study of the behavior of the Mg-Ca-Zn alloy metal foam which evaluated by SEM, EDX, and electrochemical corrosion test in Hank’s solutions. After exposure, the SEM result of Mg-Ca-Zn-3TiH2 to Hank’s solution, a volcano-like structure is formed. The streams of H2 bubbles form at local sites on the Mg alloy surface where electrochemical reactions are taking place, leading to the particular structure with around shape and often with a hole in the center. The corresponding EDS result maps reveal enrichment of O, Ca, P and Mg as corrosion product. Potentiodynamic polarization experiments conducted at 37 °C and pH 7.4 indicated the increased biodegradation rates resulted from porous structure of foam samples. Corrosion rate in 500oC sintering temperature were 1.99 millimiles per year (mmpy) with corrosion current density (I corr ) 87.3.10-6 A/cm2, corrosion rate in 550 °C sintering temperature were 2,16 mmpy with I corr 94.4.10-6 A/cm2 and rate in 600 °C sintering temperature were 2.41 mmpy with I corr 105.10-6 A/cm2. The results showed that the increasing of sintering

Moral Identity as Moral Ideal Self: Links to Adolescent Outcomes

ERIC Educational Resources Information Center

Hardy, Sam A.; Walker, Lawrence J.; Olsen, Joseph A.; Woodbury, Ryan D.; Hickman, Jacob R.

2014-01-01

The purposes of this study were to conceptualize moral identity as moral ideal self, to develop a measure of this construct, to test for age and gender differences, to examine links between moral ideal self and adolescent outcomes, and to assess purpose and social responsibility as mediators of the relations between moral ideal self and outcomes.…

Simulation of ideal-gas flow by nitrogen and other selected gases at cryogenic temperatures. [transonic flow in cryogenic wind tunnels

NASA Technical Reports Server (NTRS)

Hall, R. M.; Adcock, J. B.

1981-01-01

The real gas behavior of nitrogen, the gas normally used in transonic cryogenic tunnels, is reported for the following flow processes: isentropic expansion, normal shocks, boundary layers, and interactions between shock waves and boundary layers. The only difference in predicted pressure ratio between nitrogen and an ideal gas which may limit the minimum operating temperature of transonic cryogenic wind tunnels occur at total pressures approaching 9 atm and total temperatures 10 K below the corresponding saturation temperature. These pressure differences approach 1 percent for both isentropic expansions and normal shocks. Alternative cryogenic test gases were also analyzed. Differences between air and an ideal diatomic gas are similar in magnitude to those for nitrogen and should present no difficulty. However, differences for helium and hydrogen are over an order of magnitude greater than those for nitrogen or air. It is concluded that helium and cryogenic hydrogen would not approximate the compressible flow of an ideal diatomic gas.

[The art of Leonardo Da Vinci as a resource to science and the ideal of nursing care].

PubMed

Nascimento, Maria Aparecida de Luca; de Brito, Isabela Jorge; Dehoul, Marcelo da Silva

2003-01-01

Theoretical reflection whose goal is to demonstrate the art a nursing team is required to show in order to perform a technical procedure for transfer of solutions from a normal vial to a microdrops vial, based on Leonardo Da Vinci's theoretical referential, inspired by his work called "Vitruvian Man", so that body harmony is kept. The authors emphasize its relationship to nursing care, viewing it from its broadest sense, and its own motto--"Science, Art and Ideal".

BeMonitored: Monitoring psychophysiology and behavior using Android in phobias.

PubMed

Brás, Susana; Soares, Sandra C; Moreira, Ricardo; Fernandes, José M

2016-09-01

It is of the utmost importance that researchers can recreate, as accurately as possible, real-life conditions in psychological studies. However, that is not always possible. Given that phobias are rather context-specific, their study is the ideal candidate to assess the feasibility of using a mobile and wearable device for obtaining physiological and behavioral data. In this article, we propose BeMonitored, a smartphone-based solution to support more ecologically valid monitoring of psychological experiments. BeMonitored delivers customizable, specific context-dependent audiovisual stimuli and uses external resources connected via Bluetooth or a smartphone's own resources, while capturing the participant's behavior, physiology, and environment. We used BeMonitored in a spider phobia case study and showed that spider phobics differed from control participants in face motion, captured by the smartphone camera. Moreover, our results also revealed heart rate differences between spider and neutral stimuli in phobic participants. The presented results emphasize the usefulness of smartphones for phobia monitoring. Considering their intrinsic characteristics, smartphones may constitute the natural evolution from the lab to more realistic contexts.

Effect of NaNO3 concentration on anodic electrochemical behavior on the Sb surface in NaOH solution

NASA Astrophysics Data System (ADS)

He, Yun-long; Xu, Rui-dong; He, Shi-wei; Chen, Han-sen; Li, Kuo; Zhu, Yun; Shen, Qing-feng

2018-03-01

The effect of NaNO3 concentration on the anodic electrochemical behavior of antimony in 4 M NaOH solution was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses. The mechanism of NO 3 - concentration effect on the anodic electrochemical behavior of antimony was proposed, and its availability was confirmed by experimental results. The effect of NaNO3 on the anodic behavior of antimony in NaOH solution can be interpreted as a stepwise formation of different antimony compounds with different NaNO3 concentrations. Metallic antimony is apt to be oxidized into Sb2O3 within the NaNO3 concentration range of 0-0.48 M. NaSbO3 can be found on the antimony surface when the NaNO3 concentration increases gradually. Insoluable NaSbO3 inhibits the anodic oxidation of antimony due to its shielding effect on the mass transport of the reactants and products. Surface morphology and composition were analyzed by X-ray photoelectron spectroscopy (XPS), scanning electronic microscopy (SEM), and electron dispersion spectroscopy (EDS) analyses. Results indicate that the anodic oxidation layer is composed of Sb2O3, NaSbO3, and Sb. The atomic proportion of antimony in the form of NaSbO3 increases with increasing NaNO3 concentration due to the powerful oxidizing property of NaNO3.

Generation of sub-part-per-billion gaseous volatile organic compounds at ambient temperature by headspace diffusion of aqueous standards through decoupling between ideal and nonideal Henry's law behavior.

PubMed

Kim, Yong-Hyun; Kim, Ki-Hyun

2013-05-21

In the analysis of volatile organic compounds in air, the preparation of their gaseous standards at low (sub-ppb) concentration levels with high reliability is quite difficult. In this study, a simple dynamic headspace-based approach was evaluated as a means of generating vapor-phase volatile organic compounds from a liquid standard in an impinger at ambient temperature (25 °C). For a given sampling time, volatile organic compound vapor formed in the headspace was swept by bypassing the sweep gas through the impinger and collected four times in quick succession in separate sorbent tubes. In each experiment, a fresh liquid sample was used for each of the four sampling times (5, 10, 20, and 30 min) at a steady flow rate of 50 mL min(-1). The air-water partitioning at the most dynamic (earliest) sweeping stage was established initially in accord with ideal Henry's law, which was then followed by considerably reduced partitioning in a steady-state equilibrium (non-ideal Henry's law). The concentrations of gaseous volatile organic compounds, collected after the steady-state equilibrium, reached fairly constant values: for instance, the mole fraction of toluene measured at a sweeping interval of 10 and 30 min averaged 1.10 and 0.99 nmol mol(-1), respectively (after the initial 10 min sampling). In the second stage of our experiment, the effect of increasing the concentrations of liquid spiking standard was also examined by collecting sweep gas samples from two consecutive 10 min runs. The volatile organic compounds, collected in the first and second 10 min sweep gas samples, exhibited ideal and nonideal Henry's law behavior, respectively. From this observation, we established numerical relationships to predict the mole fraction (or mixing ratio) of each volatile organic compound in steady-state equilibrium in relation to the concentration of standard spiked into the system. This experimental approach can thus be used to produce sub-ppb levels of gaseous volatile organic

Jung's Red Book and its relation to aspects of German idealism.

PubMed

Bishop, Paul

2012-06-01

The late nineteenth century saw a renaissance of interest in the thought of the German Romantic philosopher, F.W.J. Schelling. This paper takes Jung's engagement with Schelling and his awareness of Schellingian ideas and interests (notably, the mysterious Kabeiroi worshipped at Samothrace) as its starting-point. It goes on to argue that a key set of problematics in German Idealism - the relation between freedom and necessity, between science and art, and ultimately between realism and idealism - offers a useful conceptual framework within which to approach Jung's Red Book. For the problem of the ideal is central to this work, which can be read as a journey from eternal ideals to the ideal of eternity. (Although the term 'idealism' has at least four distinct meanings, their distinct senses can be related in different ways to Jung's thinking.) The eloquent embrace of idealism by F.T. Vischer in a novel, Auch Einer, for which Jung had the highest praise, reminds us of the persistence of this tradition, which is still contested and debated in the present day. © 2012, The Society of Analytical Psychology.

Corrosion behavior of aluminum-alumina composites in aerated 3.5 percent chloride solution

NASA Astrophysics Data System (ADS)

Acevedo Hurtado, Paul Omar

Aluminum based metal matrix composites are finding many applications in engineering. Of these Al-Al2O3 composites appear to have promise in a number of defense applications because of their mechanical properties. However, their corrosion behavior remains suspect, especially in marine environments. While efforts are being made to improve the corrosion resistance of Al-Al2O3 composites, the mechanism of corrosion is not well known. In this study, the corrosion behavior of powder metallurgy processed Al-Cu alloy reinforced with 10, 15, 20 and 25 vol. % Al2O3 particles (XT 1129, XT 2009, XT 2048, XT 2031) was evaluated in aerated 3.5% NaCl solution using microstructural and electrochemical measurements. AA1100-O and AA2024T4 monolithic alloys were also studied for comparison purposes. The composites and unreinforced alloys were subjected to potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) testing. Addition of 25 vol. % Al2O 3 to the base alloys was found to increase its corrosion resistance considerably. Microstructural studies revealed the presence of intermetallic Al2Cu particles in these composites that appeared to play an important role in the observations. Pitting potential for these composites was near corrosion potential values, and repassivation potential was below the corresponding corrosion potential, indicating that these materials begin to corrode spontaneously as soon as they come in contact with the 3.5 % NaCl solution. EIS measurements indicate the occurrence of adsorption/diffusion phenomena at the interface of the composites which ultimately initiate localized or pitting corrosion. Polarization resistance values were extracted from the EIS data for all the materials tested. Electrically equivalent circuits are proposed to describe and substantiate the corrosive processes occurring in these Al-Al2O 3 composite materials.

A comparison between the electrochemical behavior of reversible magnesium and lithium electrodes

NASA Astrophysics Data System (ADS)

Aurbach, D.; Gofer, Y.; Schechter, A.; Chusid, O.; Gizbar, H.; Cohen, Y.; Moshkovich, M.; Turgeman, R.

This paper describes briefly the difference between reversible lithium and magnesium electrodes. In the case of lithium, the active metal is always covered by surface films. Li dissolution-deposition is reversible only when the surface films contain elastomers and are flexible. Hence, they can accommodate the morphological changes of the electrode during the electrochemical processes without breaking down. In an ideal situation, lithium is deposited beneath the surface films, while being constantly protected in a way that prevents reactions between freshly deposited lithium and solution species. In contrast to lithium, magnesium electrodes are reversible only in solutions where surface film free conditions exist. Mg does not react with ethers, and thus, in ethereal solutions of Grignard reagents (RMgX, where R=alkyl, aryl, X=halide) and complexes of the following type: Mg(AlX 4- nR n' R n″ ') 2, R and R'=alkyl groups, X=halide, A=Al, 0< n<4 and n'+ n''= n, magnesium electrodes behave reversibly. However, it should be noted that the above stoichiometry of the Mg salts does not reflect the true structure of the active ions in solutions. Mg deposition does not occur via electron transfer to simply solvated Mg 2+ ions. The behavior of Mg electrodes in these solutions is discussed in light of studies by EQCM, EIS, FTIR, XPS, STM and standard electrochemical techniques.

Passivation and electrochemical behavior of 316L stainless steel in chlorinated simulated concrete pore solution

NASA Astrophysics Data System (ADS)

Luo, Hong; Su, Huaizhi; Dong, Chaofang; Li, Xiaogang

2017-04-01

In this paper, the passivation and electrochemical behavior of 316L stainless steel in chlorinated simulated concrete pore solutions at different pH was evaluated by potentiodynamic measurements, electrochemical impedance spectroscopy. The composition of the passive film and surface morphology were investigated by X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and scanning electron microscopy, respectively. The results reveal that metastable pitting susceptibility, stable pitting corrosion, and composition of the passive film are influenced by pH value. After long time immersion, a bilayer structure passive film can be formed in this environment. The appearance of molybdates on the outermost surface layer, further enhancing the stability of the passive film. Moreover, the good pitting corrosion resistance of 316L stainless steel in simulated concrete pore solution without carbonated is mainly due to the presence of high Cr/Fe ratio and molybdates ions within the passive film.

Idealized vs. Realistic Microstructures: An Atomistic Simulation Case Study on γ/γ' Microstructures.

PubMed

Prakash, Aruna; Bitzek, Erik

2017-01-23

Single-crystal Ni-base superalloys, consisting of a two-phase γ / γ ' microstructure, retain high strengths at elevated temperatures and are key materials for high temperature applications, like, e.g., turbine blades of aircraft engines. The lattice misfit between the γ and γ ' phases results in internal stresses, which significantly influence the deformation and creep behavior of the material. Large-scale atomistic simulations that are often used to enhance our understanding of the deformation mechanisms in such materials must accurately account for such misfit stresses. In this work, we compare the internal stresses in both idealized and experimentally-informed, i.e., more realistic, γ / γ ' microstructures. The idealized samples are generated by assuming, as is frequently done, a periodic arrangement of cube-shaped γ ' particles with planar γ / γ ' interfaces. The experimentally-informed samples are generated from two different sources to produce three different samples-the scanning electron microscopy micrograph-informed quasi-2D atomistic sample and atom probe tomography-informed stoichiometric and non-stoichiometric atomistic samples. Additionally, we compare the stress state of an idealized embedded cube microstructure with finite element simulations incorporating 3D periodic boundary conditions. Subsequently, we study the influence of the resulting stress state on the evolution of dislocation loops in the different samples. The results show that the stresses in the atomistic and finite element simulations are almost identical. Furthermore, quasi-2D boundary conditions lead to a significantly different stress state and, consequently, different evolution of the dislocation loop, when compared to samples with fully 3D boundary conditions.

Changes in the flagellar bundling time account for variations in swimming behavior of flagellated bacteria in viscous media

NASA Astrophysics Data System (ADS)

Qu, Zijie; Temel, Fatma; Henderikx, Rene; Breuer, Kenneth

2017-11-01

The motility of bacteria E.coli in viscous fluids has been widely studied, although conflicting results on the effect of viscosity on swimming speed abound. The swimming mode of wild-type E.coli is idealized as a run-and-tumble sequence in which periods of straight swimming at a constant speed are randomly interrupted by a tumble, defined as a sudden change of direction with a very low speed. Using a tracking microscope, we follow cells for extended time and find that the swimming behavior of a single cell can exhibit a variety of behaviors including run-and-tumble and ``slow-random-walk'' in which the cells move at relatively low speed without the characteristic run. Although the characteristic swimming speed varies between individuals and in different polymer solutions, we find that the skewness of the speed distribution is solely a function of viscosity, and uniquely determines the ratio of the average speed to the characteristic run speed. Using Resistive Force Theory and the cell-specific measured characteristic run speed, we show that differences in the swimming behavior observed in solutions of different viscosity are due to changes in the flagellar bundling time, which increases as the viscosity rises, due to lower rotation rate of the flagellar motor. National Science Foundation.

Esophageal aerodynamics in an idealized experimental model of tracheoesophageal speech

NASA Astrophysics Data System (ADS)

Erath, Byron D.; Hemsing, Frank S.

2016-03-01

Flow behavior is investigated in the esophageal tract in an idealized experimental model of tracheoesophageal speech. The tracheoesophageal prosthesis is idealized as a first-order approximation using a straight, constant diameter tube. The flow is scaled according to Reynolds, Strouhal, and Euler numbers to ensure dynamic similarity. Flow pulsatility is produced by a driven orifice that approximates the kinematics of the pharyngoesophageal segment during tracheoesophageal speech. Particle image velocimetry data are acquired in three orthogonal planes as the flow exits the model prosthesis and enters the esophageal tract. Contrary to prior investigations performed in steady flow with the prosthesis oriented in-line with the flow direction, the fluid dynamics are shown to be highly unsteady, suggesting that the esophageal pressure field will be similarly complex. A large vortex ring is formed at the inception of each phonatory cycle, followed by the formation of a persistent jet. This vortex ring appears to remain throughout the entire cycle due to the continued production of vorticity resulting from entrainment between the prosthesis jet and the curved esophageal walls. Mean flow in the axial direction of the esophagus produces significant stretching of the vortex throughout the phonatory cycle. The stagnation point created by the jet impinging on the esophageal wall varies throughout the cycle due to fluctuations in the jet trajectory, which most likely arises due to flow separation within the model prosthesis. Applications to tracheoesophageal speech, including shortcomings of the model and proposed future plans, are discussed.

Couette shear of an ideal 2D photo-elastic granular system

NASA Astrophysics Data System (ADS)

Wang, Meimei; Zheng, Hu; BaréS, Jonathan; Wang, Dong; Behringe, Robert

In this study, Couette shear experiments are conducted using 2D photoelastic granular particles, which allows us to apply infinite shear strain to the granular system. We obtain force information st the granular scale using the calibrated photo-elastic grain force response. The whole granular system is density matched in salt solution, which guarantees an ideal 2D system without basal friction between the particles and the table. The viscosity is negligible at the very small shear strain rate (0.017 rpm). This talk will address two main points: i) how does the system reach a jammed state; ii) how does system reach a long term stable state and what are the properties of that state. NSF Grant No. DMR1206351, NASA Grant No. NNX15AD38G and the W.M. Keck Foundation.

Chocolate Milk with Chia Oil: Ideal Sweetness, Sweeteners Equivalence, and Dynamic Sensory Evaluation Using a Time-Intensity Methodology.

PubMed

Rodrigues, J B; Paixão, J A; Cruz, A G; Bolini, H M A

2015-12-01

The ideal sucrose concentration and equivalent concentrations of the stevia, sucralose, aspartame, and neotame in chocolate milk with chia oil as well as the dynamic behavior of certain sensory attributes were investigated using a time-intensity methodology. The use of just-about-right (JAR) identified an ideal sucrose concentration of 9% (w/w). In addition, the magnitude estimation method showed that stevia had the lowest sweetness power whereas neotame presented the highest. Furthermore, the time-intensity analysis indicated that there was no significant change between the maximum intensities of the sweetness for any evaluated sweeteners. In general, the desired sensory profile and some economic considerations are decisive on the choice of which sweetener is better to be used in chocolate milk formulation added with chia oil. © 2015 Institute of Food Technologists®

Corrosion and Discharge Behaviors of Al-Mg-Sn-Ga-In in Different Solutions

NASA Astrophysics Data System (ADS)

Xiong, Hanqing; Yin, Xiang; Yan, Yang; Dai, Yilong; Fan, Sufeng; Qiao, Xueyan; Yu, Kun

2016-08-01

Al-0.5 wt.%Mg-0.08 wt.%Sn-0.05 wt.%Ga-0.05 wt.%In and Al-0.5 wt.%Mg-0.08 wt.%Sn-0.05 wt.%Ga alloys were prepared by melting, casting and cold rolling. Corrosion and discharge behaviors of the two experimental alloys were investigated by electrochemical measurement, self-corrosion rate measurement, air battery testing, and scanning electron microscopy. The results showed that Al-Mg-Sn-Ga-In alloy exhibited higher electrochemical activity than Al-Mg-Sn-Ga alloy in 2 M NaCl solution, while it showed lower electrochemical activity than Al-Mg-Sn-Ga alloy in 4 M NaOH solution. By comparison with the air battery based on Al-Mg-Sn-Ga alloy, the battery with Al-Mg-Sn-Ga-In alloy cannot exhibit better discharge performance in 4 M NaOH electrolyte. However, the performance of the air battery based on Al-Mg-Sn-Ga-In alloy was greatly improved due to the In-rich inclusions and the uniform corroded morphology in 2 M NaCl electrolyte. Thus, Al-Mg-Sn-Ga-In alloy was a good anode material for Al-air battery in 2 M NaCl electrolyte.

Marital Aspirations, Sexual Behaviors, and HIV/AIDS in Rural Malawi

PubMed Central

Clark, Shelley; Poulin, Michelle; Kohler, Hans-Peter

2009-01-01

We explore how marital aspirations are related to the sexual behaviors of adolescents and young adults in Malawi, where HIV/AIDS prevalence among adults exceeds 10%. We also consider whether the specter of AIDS is shaping ideals about marriage. By combining survey data (N = 1,087) and in-depth interviews (N = 133) with young Malawians from the Malawi Diffusion and Ideational Change Project, we show that looking for and finding a suitable spouse are linked to sexual behaviors and, thus, HIV risks. Moreover, concerns about contracting HIV are closely tied to the ideal characteristics of a future spouse. Our findings draw long-overdue attention to the importance of marital aspirations in understanding adolescent sexual behaviors and risks in the era of AIDS. PMID:20161389

Ideal-Magnetohydrodynamic-Stable Tilting in Field-Reversed Configurations

NASA Astrophysics Data System (ADS)

Kanno, Ryutaro; Ishida, Akio; Steinhauer, Loren

1995-02-01

The tilting mode in field-reversed configurations (FRC) is examined using ideal-magnetohydrodynamic stability theory. Tilting, a global mode, is the greatest threat for disruption of FRC confinement. Previous studies uniformly found tilting to be unstable in ideal theory: the objective here is to ascertain if stable equilibria were overlooked in past work. Solving the variational problem with the Rayleigh-Ritz technique, tilting-stable equilibria are found for sufficiently hollow current profile and sufficient racetrackness of the separatrix shape. Although these equilibria were not examined previously, the present conclusion is quite surprising. Consequently checks of the method are offered. Even so it cannot yet be claimed with complete certainty that stability has been proved: absolute confirmation of ideal-stable tilting awaits the application of more complete methods.

Inelastic column behavior

NASA Technical Reports Server (NTRS)

Duberg, John E; Wilder, Thomas W , III

1952-01-01

The significant findings of a theoretical study of column behavior in the plastic stress range are presented. When the behavior of a straight column is regarded as the limiting behavior of an imperfect column as the initial imperfection (lack of straightness) approaches zero, the departure from the straight configuration occurs at the tangent-modulus load. Without such a concept of the behavior of a straight column, one is led to the unrealistic conclusion that lateral deflection of the column can begin at any load between the tangent-modulus value and the Euler load, based on the original elastic modulus. A family of curves showing load against lateral deflection is presented for idealized h-section columns of various lengths and of various materials that have a systematic variation of their stress-strain curves.

Single molecule magnet behavior of a pentanuclear Mn-based metallacrown complex: solid state and solution magnetic studies.

PubMed

Zaleski, Curtis M; Tricard, Simon; Depperman, Ezra C; Wernsdorfer, Wolfgang; Mallah, Talal; Kirk, Martin L; Pecoraro, Vincent L

2011-11-21

The magnetic behavior of the pentanuclear complex of formula Mn(II)(O(2)CCH(3))(2)[12-MC(Mn(III)(N)shi)-4](DMF)(6), 1, was investigated using magnetization and magnetic susceptibility measurements both in the solid state and in solution. Complex 1 has a nearly planar structure, made of a central Mn(II) ion surrounded by four peripheral Mn(III) ions. Solid state variable-field dc magnetic susceptibility experiments demonstrate that 1 possesses a low value for the total spin in the ground state; fitting appropriate expressions to the data results in antiferromangetic coupling both between the peripheral Mn(III) ions (J = -6.3 cm(-1)) and between the central Mn(II) ion and the Mn(III) ones (J' = -4.2 cm(-1)). In order to obtain a reasonable fit, a relatively large single ion magnetic anisotropy (D) value of 1 cm(-1) was necessary for the central Mn(II) ion. The single crystal magnetization measurements using a microsquid array display a very slight opening of the hysteresis loop but only at a very low temperature (0.04 K), which is in line with the ac susceptibility data where a slow relaxation of the magnetization occurs just around 2 K. In frozen solution, complex 1 displays a frequency dependent ac magnetic susceptibility signal with an energy barrier to magnetization reorientation (E) and relaxation time at an infinite temperature (τ(o)) of 14.7 cm(-1) and 1.4 × 10(-7) s, respectively, demonstrating the single molecule magnetic behavior in solution.

International Fertility Change: New Data and Insights from the Developmental Idealism Framework

PubMed Central

Thornton, Arland; Binstock, Georgina; Yount, Kathryn M.; Abbasi-Shavazi, Mohammad Jalal; Ghimire, Dirgha; Xie, Yu

2012-01-01

Many scholars have offered structural and ideational explanations for the fertility changes occurring around the world. This paper focuses on the influence of developmental idealism—a schema or set of beliefs endorsing development, fertility change, and causal connections between development and fertility. Developmental idealism is argued to be an important force affecting both population policy and the fertility behavior of ordinary people. We present new survey data from ordinary people in six countries—Argentina, China, Egypt, Iran, Nepal, and the United States—about the extent to which developmental idealism is known and believed. We ask individuals if they believe that fertility and development are correlated, that development is a causal force in changing fertility levels, and that fertility declines enhance the standard of living and intergenerational relations. We also ask people about their expectations concerning future trends in fertility in their countries and whether they approve or disapprove of the trends they expect. The data show widespread linkage in the minds of ordinary people between fertility and development. Large fractions of people in these six settings believe that fertility and development are correlated, that development reduces fertility, and that fertility declines foster development. Many also expect and endorse future declines in fertility. PMID:22403035

Primitive ideals of C q [ SL(3)

NASA Astrophysics Data System (ADS)

Hodges, Timothy J.; Levasseur, Thierry

1993-10-01

The primitive ideals of the Hopf algebra C q [ SL(3)] are classified. In particular it is shown that the orbits in Prim C q [ SL(3)] under the action of the representation group H ≅ C *× C * are parameterized naturally by W×W, where W is the associated Weyl group. It is shown that there is a natural one-to-one correspondence between primitive ideals of C q [ SL(3)] and symplectic leaves of the associated Poisson algebraic group SL(3, C).

Rheological Behavior Xanthan and SlurryPro Polymer Solutions Evaluated as Shear Thinning Delivery Fluids for Subsurface Remediation

NASA Astrophysics Data System (ADS)

Zhong, L.; Oostrom, M.; Truex, M.; Vermeul, V.

2011-12-01

Shear thinning fluids can be applied as a delivery means to enhance the uniformity of remedial amendment distribution in heterogeneous aquifers, thereby to improve remediation performance. The rheological behavior of biopolymer xanthan gum and synthetic polymer SlurryPro were tested, and their influence on the amendment delivery performance was evaluated. The impact of polymer concentration, basic water chemistry, salinity (e.g., Br-, Na+, Ca2+ concentrations), remedial amendments (phosphate, sodium lactate, ethyl lactate, lactate oil, whey), sediments, and the mixing approach on the rheological properties of the polymer solutions was determined. The SlurryPro polymer lost shear-thinning properties even at relatively low solution ionic strength. However, the xanthan gum polymer maintained shear-thinning properties under most of the tested conditions, though with some loss in absolute viscosity with increasing ionic strength. Xanthan appeared to be the better candidate for enhanced amendment delivery. Increasing in xanthan concentration not only increased the solution viscosity, but also increased degree of shear thinning. Addition of salt decreased the solution viscosity and the degree of shear thinning, while the influence was diminished when the polymer concentration was higher. After reaching a critical xanthan concentration, addition of salt increased solution viscosity. The degradation of xanthan and SlurryPro in the presence of site aquifer materials and microbes was studied in batch tests in which the field sediment/water ratio was simulated. The viscosity of the polymer solutions dropped 85% or more in the first week, while the solution chemical oxygen demand (COD) decreasing occurred at a much slower rate.

Temperature and the Ideal Gas

ERIC Educational Resources Information Center

Daisley, R. E.

1973-01-01

Presents some organized ideas in thermodynamics which are suitable for use with high school (GCE A level or ONC) students. Emphases are placed upon macroscopic observations and intimate connection of the modern definition of temperature with the concept of ideal gas. (CC)

Ideal photon number amplifier and duplicator

NASA Technical Reports Server (NTRS)

Dariano, G. M.

1992-01-01

The photon number-amplification and number-duplication mechanism are analyzed in the ideal case. The search for unitary evolutions leads to consider also a number-deamplification mechanism, the symmetry between amplification and deamplification being broken by the integer-value nature of the number operator. Both transformations, amplification and duplication, need an auxiliary field which, in the case of amplification, turns out to be amplified in the inverse way. Input-output energy conservation is accounted for using a classical pump or through frequency-conversion of the fields. Ignoring one of the fields is equivalent to considering the amplifier as an open system involving entropy production. The Hamiltonians of the ideal devices are given and compared with those of realistic systems.

Effect of Stress Ratio and Loading Frequency on the Corrosion Fatigue Behavior of Smooth Steel Wire in Different Solutions

PubMed Central

Wang, Songquan; Zhang, Dekun; Hu, Ningning; Zhang, Jialu

2016-01-01

In this work, the effects of loading condition and corrosion solution on the corrosion fatigue behavior of smooth steel wire were discussed. The results of polarization curves and weight loss curves showed that the corrosion of steel wire in acid solution was more severe than that in neutral and alkaline solutions. With the extension of immersion time in acid solution, the cathodic reaction of steel wire gradually changed from the reduction of hydrogen ion to the reduction of oxygen, but was always the reduction of hydrogen ion in neutral and alkaline solutions. The corrosion kinetic parameters and equivalent circuits of steel wires were also obtained by simulating the Nyquist diagrams. In corrosion fatigue test, the effect of stress ratio and loading frequency on the crack initiation mechanism was emphasized. The strong corrosivity of acid solution could accelerate the nucleation of crack tip. The initiation mechanism of crack under different conditions was summarized according to the side and fracture surface morphologies. For the crack initiation mechanism of anodic dissolution, the stronger the corrosivity of solution was, the more easily the fatigue crack source formed, while, for the crack initiation mechanism of deformation activation, the lower stress ratio and higher frequency would accelerate the generation of corrosion fatigue crack source. PMID:28773869

Innovation in neurosurgery: less than IDEAL? A systematic review.

PubMed

Muskens, I S; Diederen, S J H; Senders, J T; Zamanipoor Najafabadi, A H; van Furth, W R; May, A M; Smith, T R; Bredenoord, A L; Broekman, M L D

2017-10-01

Surgical innovation is different from the introduction of novel pharmaceuticals. To help address this, in 2009 the IDEAL Collaboration (Idea, Development, Exploration, Assessment, Long-term follow-up) introduced the five-stage framework for surgical innovation. To evaluate the framework feasibility for novel neurosurgical procedure introduction, two innovative surgical procedures were examined: the endoscopic endonasal approach for skull base meningiomas (EEMS) and the WovenEndobridge (WEB device) for endovascular treatment of intracranial aneurysms. The published literature on EEMS and WEB devices was systematically reviewed. Identified studies were classified according to the IDEAL framework stage. Next, studies were evaluated for possible categorization according to the IDEAL framework. Five hundred seventy-six papers describing EEMS were identified of which 26 papers were included. No prospective studies were identified, and no studies reported on ethical approval or patient informed consent for the innovative procedure. Therefore, no clinical studies could be categorized according to the IDEAL Framework. For WEB devices, 6229 articles were screened of which 21 were included. In contrast to EEMS, two studies were categorized as 2a and two as 2b. The results of this systematic review demonstrate that both EEMS and WEB devices were not introduced according to the (later developed in the case of EEMS) IDEAL framework. Elements of the framework such as informed consent, ethical approval, and rigorous outcomes reporting are important and could serve to improve the quality of neurosurgical research. Alternative study designs and the use of big data could be useful modifications of the IDEAL framework for innovation in neurosurgery.

Corrosion behavior of a superduplex stainless steel in chloride aqueous solution

NASA Astrophysics Data System (ADS)

Dabalà, Manuele; Calliari, Irene; Variola, Alessandra

2004-04-01

Super duplex stainless steels (SDSS) have been widely used as structural materials for chemical plants (especially in those engaged in phosphoric acid production), in the hydrometallurgy industries, and as materials for offshore applications due to their excellent corrosion resistance in chloride environments, compared with other commercial types of ferritic stainless steels. These alloys also possess superior weldability and better mechanical properties than austenitic stainless steels. However, due to their two-phase structure, the nature of which is very dependent on their composition and thermal history, the behavior of SDSS regarding localized corrosion appears difficult to predict, especially in chloride environments. To improve their final properties, the effect of the partition of the alloying elements between the two phases, and the composition and microstructure of each phase are the key to understanding the localized corrosion phenomena of SDSS. This paper concerns the effects of the SDSS microstructure and heat treatment on the SDSS corrosion resistance in aqueous solutions, containing different amounts of NaCl at room temperature.

The developmental effects of media-ideal internalization and self-objectification processes on adolescents' negative body-feelings, dietary restraint, and binge eating.

PubMed

Dakanalis, Antonios; Carrà, Giuseppe; Calogero, Rachel; Fida, Roberta; Clerici, Massimo; Zanetti, Maria Assunta; Riva, Giuseppe

2015-08-01

Despite accumulated experimental evidence of the negative effects of exposure to media-idealized images, the degree to which body image, and eating related disturbances are caused by media portrayals of gendered beauty ideals remains controversial. On the basis of the most up-to-date meta-analysis of experimental studies indicating that media-idealized images have the most harmful and substantial impact on vulnerable individuals regardless of gender (i.e., "internalizers" and "self-objectifiers"), the current longitudinal study examined the direct and mediated links posited in objectification theory among media-ideal internalization, self-objectification, shame and anxiety surrounding the body and appearance, dietary restraint, and binge eating. Data collected from 685 adolescents aged between 14 and 15 at baseline (47 % males), who were interviewed and completed standardized measures annually over a 3-year period, were analyzed using a structural equation modeling approach. Results indicated that media-ideal internalization predicted later thinking and scrutinizing of one's body from an external observer's standpoint (or self-objectification), which then predicted later negative emotional experiences related to one's body and appearance. In turn, these negative emotional experiences predicted subsequent dietary restraint and binge eating, and each of these core features of eating disorders influenced each other. Differences in the strength of these associations across gender were not observed, and all indirect effects were significant. The study provides valuable information about how the cultural values embodied by gendered beauty ideals negatively influence adolescents' feelings, thoughts and behaviors regarding their own body, and on the complex processes involved in disordered eating. Practical implications are discussed.

Elastin: a representative ideal protein elastomer.

PubMed Central

Urry, D W; Hugel, T; Seitz, M; Gaub, H E; Sheiba, L; Dea, J; Xu, J; Parker, T

2002-01-01

During the last half century, identification of an ideal (predominantly entropic) protein elastomer was generally thought to require that the ideal protein elastomer be a random chain network. Here, we report two new sets of data and review previous data. The first set of new data utilizes atomic force microscopy to report single-chain force-extension curves for (GVGVP)(251) and (GVGIP)(260), and provides evidence for single-chain ideal elasticity. The second class of new data provides a direct contrast between low-frequency sound absorption (0.1-10 kHz) exhibited by random-chain network elastomers and by elastin protein-based polymers. Earlier composition, dielectric relaxation (1-1000 MHz), thermoelasticity, molecular mechanics and dynamics calculations and thermodynamic and statistical mechanical analyses are presented, that combine with the new data to contrast with random-chain network rubbers and to detail the presence of regular non-random structural elements of the elastin-based systems that lose entropic elastomeric force upon thermal denaturation. The data and analyses affirm an earlier contrary argument that components of elastin, the elastic protein of the mammalian elastic fibre, and purified elastin fibre itself contain dynamic, non-random, regularly repeating structures that exhibit dominantly entropic elasticity by means of a damping of internal chain dynamics on extension. PMID:11911774

Topological photonic crystal with ideal Weyl points

NASA Astrophysics Data System (ADS)

Wang, Luyang; Jian, Shao-Kai; Yao, Hong

Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on symmetry analysis, we show that a minimal number of symmetry-related Weyl points can be realized in time-reversal invariant photonic crystals. We propose to realize these ``ideal'' Weyl points in modified double-gyroid photonic crystals, which is confirmed by our first-principle photonic band-structure calculations. Photonic crystals with ideal Weyl points are qualitatively advantageous in applications such as angular and frequency selectivity, broadband invisibility cloaking, and broadband 3D-imaging.

Determination of performance of non-ideal aluminized explosives.

PubMed

Keshavarz, Mohammad Hossein; Mofrad, Reza Teimuri; Poor, Karim Esmail; Shokrollahi, Arash; Zali, Abbas; Yousefi, Mohammad Hassan

2006-09-01

Non-ideal explosives can have Chapman-Jouguet (C-J) detonation pressure significantly different from those expected from existing thermodynamic computer codes, which usually allows finding the parameters of ideal detonation of individual high explosives with good accuracy. A simple method is introduced by which detonation pressure of non-ideal aluminized explosives with general formula C(a)H(b)N(c)O(d)Al(e) can be predicted only from a, b, c, d and e at any loading density without using any assumed detonation products and experimental data. Calculated detonation pressures show good agreement with experimental values with respect to computed results obtained by complicated computer code. It is shown here how loading density and atomic composition can be integrated into an empirical formula for predicting detonation pressure of proposed aluminized explosives.

Effect of Minor Alloying Elements on Localized Corrosion Behavior of Aluminum-Copper-Magnesium based Solid Solution Alloys

NASA Astrophysics Data System (ADS)

Aburada, Tomohiro

2011-12-01

The effects and mechanistic roles of a minor alloying element, Ni, on the localized corrosion behavior were explored by studying (Al75Cu 17Mg8)97Ni3 and Al70Cu 18Mg12 amorphous alloys. To explore the minor alloying element limited to the outer surface layers, the corrosion behavior of Al70Cu 18Mg12 amorphous alloy in solutions with and without Ni 2+ was also studied. Both Ni alloying and Ni2+ in solution improved the localized corrosion resistance of the alloys by ennobling the pitting and repassivation potentials. Pit growth by the selective dissolution of Al and Mg was also suppressed by Ni alloying. Remaining Cu and Ni reorganized into a Cu-rich polycrystalline nanoporous structure with continuous ligaments in pits. The minor Ni alloying and Ni2+ in solution suppressed the coarsening of the ligaments in the dealloyed nanoporous structure. The presence of relatively immobile Ni atoms at the surface suppressed the surface diffusion of Cu, which reduced the coarsening of the nanoporous structure, resulting in the formation of 10 to 30 nm wide Cu ligaments. Two mechanistic roles of minor alloying elements in the improvement of the pitting corrosion resistance of the solid solution alloys are elucidated. The first role is the suppression of active dissolution by altering the atomic structure. Ni in solid solution formed stronger bonds with Al, and reduces the probability of weaker Al-Al bonds. The second role is to hinder dissolution by producing a greater negative shift of the true interfacial potential at the dissolution front under the dealloyed layer due to the greater Ohmic resistance through the finer porous structure. These effects contributed to the elevation of pitting potentials by ennobling the applied potential required to produce enough dissolution for the stabilization of pits. Scientifically, this thesis advances the state of understanding of alloy dissolution, particularly the role of minor alloying elements on preferential oxidation at the atomic

Sol-gel transition behavior of aqueous peptide-amphiphile (C16-W3K) solutions: effects of alkyl-tail length, mechanical shear, temperature, and salt

NASA Astrophysics Data System (ADS)

Yamamoto, Masashi; Otsuka, Takahiro; Orimo, Yoshinori; Maeda, Tomoki; Hotta, Atsushi

Peptide amphiphiles (PA) possess nanoscale micelle structures and excellent biocompatibility. In aqueous PA solution, PA molecules can self-assemble through various configurations into spherical and wormlike micelles, which can occasionally form hydrogels. C16-W3K is one of the unique PA, whose micelle configurations can transfer from spherical to wormlike structures in its aqueous solution over time, while the wormlike micelles could also lead to gelation. In our recent research, the effects of the length of the hydrophobic alkyl tail and other external factors of C16-W3K on the gelation behavior of the C16-W3K solution have been discussed. It has been revealed that longer alkyl-tails could facilitate the gelation of the C16-W3K solution, and that the external stimuli, such as mechanical shear and heat, could promote faster gelation of the C16-W3K solution. It was also found that salt could adjust the pH of the C16-W3K solution, having profound influence on the gelation behavior of the C16-W3K solution. In fact, the gelation of the C16-W3K with a higher storage modulus could be obtained from relatively acidic solutions, while the gelation of the C16-W3K solution was firmly suppressed in highly basic solutions. This work was supported by a Grant-in-Aid for Scientific Research (A) (No. 15H02298 to A.H.) and a Grant-in-Aid for Research Activity Start-up (No.15H06586 to T.M.) from JSPS: KAKENHI.

Analysis of all-frequency variational behavior of the Kirchhoff approximation for a classic surface-scattering model

NASA Technical Reports Server (NTRS)

Bird, J. F.

1985-01-01

In testing a stochastic variational principle at high frequencies by using a Kirchhoffean trial function in an idealized model for surface scattering - a randomly embossed plane - we have found not only the predicted high-frequency improvement but also an unexpected low-frequency improvement in the calculated scattering amplitudes. To investigate systematically the all-frequency variational behavior, we consider here the deterministic one-boss case - Rayleigh's classic model whose exact solution is available for comparison - over all wavelengths, polarizations, and configurations of incidence and scattering. We examine analytically in particular the long-wave limit of the variational-Kirchhoff amplitudes; the results demonstrate improvements in both wavelength and angle depedence for horizontal (TM) polarization and some variational improvements for vertical (TE) polarization. This low-frequency behavior in tandem with the foreseen high-frequency improvement leads to good variational-Kirchhoff results through the intermediate resonance-frequency regime for this model.

Prevalence of ideal cardiovascular health in European adolescents: The HELENA study.

PubMed

Henriksson, Pontus; Henriksson, Hanna; Gracia-Marco, Luis; Labayen, Idoia; Ortega, Francisco B; Huybrechts, Inge; España-Romero, Vanesa; Manios, Yannis; Widhalm, Kurt; Dallongeville, Jean; González-Gross, Marcela; Marcos, Ascensión; Moreno, Luis A; Castillo, Manuel J; Ruiz, Jonatan R

2017-08-01

The ideal cardiovascular health (iCVH) construct consists of 4 health behaviours and 3 health factors and is strongly related to later cardiovascular disease. However, the prevalence of iCVH in European adolescents is currently unknown. The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study is a cross-sectional, multicentre study conducted in 9 European countries during 2006-2007 and included 3528 adolescents (1683 boys and 1845 girls) between 12.5 and 17.5years of age. Status (ideal vs. non-ideal) for the health behaviours (smoking status, body mass index, physical activity and diet) and health factors (total cholesterol, blood pressure and fasting glucose) were determined. Overall, the prevalence of ideal health behaviours was low; non-smoking (60.9% ideal), body mass index (76.8%), physical activity (62.1%), and diet (1.7%). The prevalence of ideal health factors was; total cholesterol (65.8%), blood pressure (62.0%) and plasma glucose (88.8%). The low prevalence of iCVH behaviours, especially diet and physical activity, identified in European adolescents is likely to influence later cardiovascular health which strongly motivates efforts to increase ideal health behaviours in this population. Copyright © 2017 Elsevier B.V. All rights reserved.

Cardiorespiratory fitness and ideal cardiovascular health in European adolescents.

PubMed

Ruiz, Jonatan R; Huybrechts, Inge; Cuenca-García, Magdalena; Artero, Enrique G; Labayen, Idoia; Meirhaeghe, Aline; Vicente-Rodriguez, German; Polito, Angela; Manios, Yannis; González-Gross, Marcela; Marcos, Ascensión; Widhalm, Kurt; Molnar, Denes; Kafatos, Anthony; Sjöström, Michael; Moreno, Luis A; Castillo, Manuel J; Ortega, Francisco B

2015-05-15

We studied in European adolescents (i) the association between cardiorespiratory fitness and ideal cardiovascular health as defined by the American Heart Association and (ii) whether there is a cardiorespiratory fitness threshold associated with a more favourable cardiovascular health profile. Participants included 510 (n=259 girls) adolescents from 9 European countries. The 20 m shuttle run test was used to estimate cardiorespiratory fitness. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviours (smoking, body mass index, physical activity and diet) and three factors (total cholesterol, blood pressure and glucose). Higher levels of cardiorespiratory fitness were associated with a higher number of ideal cardiovascular health components in both boys and girls (both p for trend ≤0.001). Levels of cardiorespiratory fitness were significantly higher in adolescents meeting at least four ideal components (13% higher in boys, p<0.001; 6% higher in girls, p=0.008). Receiver operating characteristic curve analyses showed a significant discriminating accuracy of cardiorespiratory fitness in identifying the presence of at least four ideal cardiovascular health components (43.8 mL/kg/min in boys and 34.6 mL/kg/min in girls, both p<0.001). The results suggest a hypothetical cardiorespiratory fitness level associated with a healthier cardiovascular profile in adolescents. The fitness standards could be used in schools as part of surveillance and/or screening systems to identify youth with poor health behaviours who might benefit from intervention programmes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

m-Diethynylbenzene macrocycles: syntheses and self-association behavior in solution.

PubMed

Tobe, Yoshito; Utsumi, Naoto; Kawabata, Kazuya; Nagano, Atsushi; Adachi, Kiyomi; Araki, Shunji; Sonoda, Motohiro; Hirose, Keiji; Naemura, Koichiro

2002-05-15

m-Diethynylbenzene macrocycles (DBMs), buta-1,3-diyne-bridged [4(n)]metacyclophanes, have been synthesized and their self-association behaviors in solution were investigated. Cyclic tetramers, hexamers, and octamers of DBMs having exo-annular octyl, hexadecyl, and 3,6,9-trioxadecyl ester groups were prepared by intermolecular oxidative coupling of dimer units or intramolecular cyclization of the corresponding open-chain oligomers. The aggregation properties were investigated by two methods, the (1)H NMR spectra and the vapor pressure osmometry (VPO). Although some discrepancies were observed between the association constants obtained from the two methods, the qualitative view was consistent with each other. The analysis of self-aggregation by VPO revealed unique aggregation behavior of DBMs in acetone and toluene, which was not elucidated by the NMR method. Namely, the association constants for infinite association are several times larger than the dimerization constant, suggesting that the aggregation is enhanced by the formation of dimers (a nucleation mechanism). In polar solvents, DBMs aggregate more strongly than in chloroform due to the solvophobic interactions between the macrocyclic framework and the solvents. Moreover, DBMs self-associate in aromatic solvents such as toluene and o-xylene more readily than in chloroform. In particular, the hexameric DBM having a large macrocyclic cavity exhibits extremely large association constants in aromatic solvents. By comparing the aggregation properties of DBMs with the corresponding acyclic oligomers, the effect of the macrocyclic structure on the aggregation propensity was clarified. Finally, it turned out that DBMs tend to aggregate more readily than the corresponding phenylacetylene macrocycles, acetylene-bridged [2(n)]metacyclophanes, owing to the withdrawal of the electron density from the aromatic rings by the butadiyne linkages which facilitates pi-pi stacking interactions.

Ideal Standards, Acceptance, and Relationship Satisfaction: Latitudes of Differential Effects

PubMed Central

Buyukcan-Tetik, Asuman; Campbell, Lorne; Finkenauer, Catrin; Karremans, Johan C.; Kappen, Gesa

2017-01-01

We examined whether the relations of consistency between ideal standards and perceptions of a current romantic partner with partner acceptance and relationship satisfaction level off, or decelerate, above a threshold. We tested our hypothesis using a 3-year longitudinal data set collected from heterosexual newlywed couples. We used two indicators of consistency: pattern correspondence (within-person correlation between ideal standards and perceived partner ratings) and mean-level match (difference between ideal standards score and perceived partner score). Our results revealed that pattern correspondence had no relation with partner acceptance, but a positive linear/exponential association with relationship satisfaction. Mean-level match had a significant positive association with actor’s acceptance and relationship satisfaction up to the point where perceived partner score equaled ideal standards score. Partner effects did not show a consistent pattern. The results suggest that the consistency between ideal standards and perceived partner attributes has a non-linear association with acceptance and relationship satisfaction, although the results were more conclusive for mean-level match. PMID:29033876

Nonideal Solute Chemical Potential Equation and the Validity of the Grouped Solute Approach for Intracellular Solution Thermodynamics.

PubMed

Zielinski, Michal W; McGann, Locksley E; Nychka, John A; Elliott, Janet A W

2017-11-22

The prediction of nonideal chemical potentials in aqueous solutions is important in fields such as cryobiology, where models of water and solute transport-that is, osmotic transport-are used to help develop cryopreservation protocols and where solutions contain many varied solutes and are generally highly concentrated and thus thermodynamically nonideal. In this work, we further the development of a nonideal multisolute solution theory that has found application across a broad range of aqueous systems. This theory is based on the osmotic virial equation and does not depend on multisolute data. Specifically, we derive herein a novel solute chemical potential equation that is thermodynamically consistent with the existing model, and we establish the validity of a grouped solute model for the intracellular space. With this updated solution theory, it is now possible to model cellular osmotic behavior in nonideal solutions containing multiple permeating solutes, such as those commonly encountered by cells during cryopreservation. In addition, because we show here that for the osmotic virial equation the grouped solute approach is mathematically equivalent to treating each solute separately, multisolute solutions in other applications with fixed solute mass ratios can now be treated rigorously with such a model, even when all of the solutes cannot be enumerated.

Couette shear of an ideal 2D photo-elastic granular system

NASA Astrophysics Data System (ADS)

Behringer, Robert; Zheng, Hu; Barés, Jonathan; Wang, Dong

2016-11-01

In this study, Couette shear experiments are conducted using 2D photoelastic granular particles, which allows us to apply infinite shear strain to the granular system. We obtain force information at the granular scale using the calibrated photo-elastic grain force response. The whole granular system is density matched in salt solution, which guarantees an ideal 2D system without basal friction between the particles and the table. The viscosity is negligible at the very small shear strain rate (0.017 rpm). This talk will address two main points: i) how does the system reach a jammed state; ii) how does system reach a long term stable state and what are the properties of that state. We acknowledge support from NSF Grant No. DMR1206351, NASA Grant No. NNX15AD38G and the W.M. Keck Foundation.

Hydration of nonelectrolytes in binary aqueous solutions

NASA Astrophysics Data System (ADS)

Rudakov, A. M.; Sergievskii, V. V.

2010-10-01

Literature data on the thermodynamic properties of binary aqueous solutions of nonelectrolytes that show negative deviations from Raoult's law due largely to the contribution of the hydration of the solute are briefly surveyed. Attention is focused on simulating the thermodynamic properties of solutions using equations of the cluster model. It is shown that the model is based on the assumption that there exists a distribution of stoichiometric hydrates over hydration numbers. In terms of the theory of ideal associated solutions, the equations for activity coefficients, osmotic coefficients, vapor pressure, and excess thermodynamic functions (volume, Gibbs energy, enthalpy, entropy) are obtained in analytical form. Basic parameters in the equations are the hydration numbers of the nonelectrolyte (the mathematical expectation of the distribution of hydrates) and the dispersions of the distribution. It is concluded that the model equations adequately describe the thermodynamic properties of a wide range of nonelectrolytes partly or completely soluble in water.

Ethnic and gender differences in ideal body size and related attitudes among Asians, Native Hawaiians, and Whites.

PubMed

Townsend, Claire; Takishima-Lacasa, Julie Y; Latner, Janet D; Grandinetti, Andrew; Keawe'aimoku Kaholokula, Joseph

2014-08-01

Often overlooked explanations for the varied obesity rates across ethno-cultural groups include differences in attitudes toward excess weight, with certain populations assumed to have larger ideal body sizes (IBS). Past studies found ethnic and gender difference in IBS across and within different groups. This study examined the effects of ethnicity and gender, and their interaction, in accounting for differences in IBS and attitudes toward those ideals. Multiple regression analyses were used to better understand the effects of ethnicity and gender in accounting for differences in perceived IBS according to ethnic-specific and Western ideals and attitudes in 1,124 people of Native Hawaiian, Filipino, Japanese, and White ancestry. The analyses controlled for socio-demographics, body mass index, health-related behaviors, and psychosocial variables. The results indicated that Native Hawaiians selected larger ethnic IBS, Filipinos selected smaller ethnic IBS, and Native Hawaiians selected slightly smaller Western IBS than other ethnic groups. Overall, males selected larger IBS compared to females. Interaction analyses indicated that the relationship between ethnic IBS and attitude toward that IBS varied as a function of ethnicity, such that Native Hawaiians who selected a larger ethnic IBS held less favorable attitudes toward that IBS. The discrepancy between Native Hawaiians' selection of larger ethnic IBS as ideal and their less positive attitude toward that selection warrants more investigation. However, it does suggest that Native Hawaiians, on a personal level, do not prefer larger body sizes, which contradicts their perceptions of social norms. These findings have important implications for obesity interventions among Native Hawaiians.

Ethnic and Gender Differences in Ideal Body Size and Related Attitudes among Asians, Native Hawaiians, and Whites

PubMed Central

Takishima-Lacasa, Julie Y; Latner, Janet D; Grandinetti, Andrew; Keawe‘aimoku Kaholokula, Joseph

2014-01-01

Often overlooked explanations for the varied obesity rates across ethno-cultural groups include differences in attitudes toward excess weight, with certain populations assumed to have larger ideal body sizes (IBS). Past studies found ethnic and gender difference in IBS across and within different groups. This study examined the effects of ethnicity and gender, and their interaction, in accounting for differences in IBS and attitudes toward those ideals. Multiple regression analyses were used to better understand the effects of ethnicity and gender in accounting for differences in perceived IBS according to ethnic-specific and Western ideals and attitudes in 1,124 people of Native Hawaiian, Filipino, Japanese, and White ancestry. The analyses controlled for socio-demographics, body mass index, health-related behaviors, and psychosocial variables. The results indicated that Native Hawaiians selected larger ethnic IBS, Filipinos selected smaller ethnic IBS, and Native Hawaiians selected slightly smaller Western IBS than other ethnic groups. Overall, males selected larger IBS compared to females. Interaction analyses indicated that the relationship between ethnic IBS and attitude toward that IBS varied as a function of ethnicity, such that Native Hawaiians who selected a larger ethnic IBS held less favorable attitudes toward that IBS. The discrepancy between Native Hawaiians' selection of larger ethnic IBS as ideal and their less positive attitude toward that selection warrants more investigation. However, it does suggest that Native Hawaiians, on a personal level, do not prefer larger body sizes, which contradicts their perceptions of social norms. These findings have important implications for obesity interventions among Native Hawaiians. PMID:25157324

Behaviorism: part of the problem or part of the solution.

PubMed Central

Holland, J G

1978-01-01

The form frequently taken by behavior-modification programs is analyzed in terms of the parent science, Behaviorism. Whereas Behaviorism assumes that behavior is the result of contingencies, and that lasting behavior change involves changing the contingencies that give rise to and support the behavior, most behavior-modification programs merely arrange special contingencies in a special environment to eliminate the "problem" behavior. Even when the problem behavior is as widespread as alcoholism and crime, behavior modifiers focus on "fixing" the alcoholic and the criminal, not on changing the societal contingencies that prevail outside the therapeutic environment and continue to produce alcoholics and criminals. The contingencies that shape this method of dealing with behavioral problems are also analyzed, and this analysis leads to a criticism of the current social structure as a behavior control system. Although applied behaviorists have frequently focused on fixing individuals, the science of Behaviorism provides the means to analyze the structures, the system, and the forms of societal control that produce the "problems". PMID:649524

Interactions in Undersaturated and Supersaturated Lysozyme Solutions: Static and Dynamic Light Scattering Results

NASA Technical Reports Server (NTRS)

Muschol, Martin; Rosenberger, Franz

1995-01-01

We have performed multiangle static and dynamic light scattering studies of lysozyme solutions at pH=4.7. The Rayleigh ratio R(sub g) and the collective diffusion coefficient D(sub c) were determined as function of both protein concentration c(sub p) and salt concentration c(sub s) with two different salts. At low salt concentrations, the scattering ratio K(sub c)(sub p)/R(sub theta) and diffusivity increased with protein concentration above the values for a monomeric, ideal solution. With increasing salt concentration this trend was eventually reversed. The hydrodynamic interactions of lysozyme in solution, extracted from the combination of static and dynamic scattering data, decreased significantly with increasing salt concentration. These observations reflect changes in protein interactions, in response to increased salt screening, from net repulsion to net attraction. Both salts had the same qualitative effect, but the quantitative behavior did not scale with the ionic strength of the solution. This indicates the presence of salt specific effects. At low protein concentrations, the slopes of K(sub c)(sub p)/R(sub theta) and D(sub c) vs c(sub p) were obtained. The dependence of the slopes on ionic strength was modeled using a DLVO potential for colloidal interactions of two spheres, with the net protein charge Z(sub e) and Hamaker constant A(sub H) as fitting parameters. The model reproduces the observed variations with ionic strength quite well. Independent fits to the static and dynamic data, however, led to different values of the fitting parameters. These and other shortcomings suggest that colloidal interaction models alone are insufficient to explain protein interactions in solutions.

Chemical Laws, Idealization and Approximation

NASA Astrophysics Data System (ADS)

Tobin, Emma

2013-07-01

This paper examines the notion of laws in chemistry. Vihalemm ( Found Chem 5(1):7-22, 2003) argues that the laws of chemistry are fundamentally the same as the laws of physics they are all ceteris paribus laws which are true "in ideal conditions". In contrast, Scerri (2000) contends that the laws of chemistry are fundamentally different to the laws of physics, because they involve approximations. Christie ( Stud Hist Philos Sci 25:613-629, 1994) and Christie and Christie ( Of minds and molecules. Oxford University Press, New York, pp. 34-50, 2000) agree that the laws of chemistry are operationally different to the laws of physics, but claim that the distinction between exact and approximate laws is too simplistic to taxonomise them. Approximations in chemistry involve diverse kinds of activity and often what counts as a scientific law in chemistry is dictated by the context of its use in scientific practice. This paper addresses the question of what makes chemical laws distinctive independently of the separate question as to how they are related to the laws of physics. From an analysis of some candidate ceteris paribus laws in chemistry, this paper argues that there are two distinct kinds of ceteris paribus laws in chemistry; idealized and approximate chemical laws. Thus, while Christie ( Stud Hist Philos Sci 25:613-629, 1994) and Christie and Christie ( Of minds and molecules. Oxford University Press, New York, pp. 34--50, 2000) are correct to point out that the candidate generalisations in chemistry are diverse and heterogeneous, a distinction between idealizations and approximations can nevertheless be used to successfully taxonomise them.

The ideal imaging AR waveguide

NASA Astrophysics Data System (ADS)

Grey, David J.

2017-06-01

Imaging waveguides are a key development that are helping to create the Augmented Reality revolution. They have the ability to use a small projector as an input and produce a wide field of view, large eyebox, full colour, see-through image with good contrast and resolution. WaveOptics is at the forefront of this AR technology and has developed and demonstrated an approach which is readily scalable. This paper presents our view of the ideal near-to-eye imaging AR waveguide. This will be a single-layer waveguide which can be manufactured in high volume and low cost, and is suitable for small form factor applications and all-day wear. We discuss the requirements of the waveguide for an excellent user experience. When enhanced (AR) viewing is not required, the waveguide should have at least 90% transmission, no distracting artifacts and should accommodate the user's ophthalmic prescription. When enhanced viewing is required, additionally, the waveguide requires excellent imaging performance, this includes resolution to the limit of human acuity, wide field of view, full colour, high luminance uniformity and contrast. Imaging waveguides are afocal designs and hence cannot provide ophthalmic correction. If the user requires this correction then they must wear either contact lenses, prescription spectacles or inserts. The ideal imaging waveguide would need to cope with all of these situations so we believe it must be capable of providing an eyebox at an eye relief suitable for spectacle wear which covers a significant range of population inter-pupillary distances. We describe the current status of our technology and review existing imaging waveguide technologies against the ideal component.

Idealized vs. Realistic Microstructures: An Atomistic Simulation Case Study on γ/γ′ Microstructures

PubMed Central

Prakash, Aruna; Bitzek, Erik

2017-01-01

Single-crystal Ni-base superalloys, consisting of a two-phase γ/γ′ microstructure, retain high strengths at elevated temperatures and are key materials for high temperature applications, like, e.g., turbine blades of aircraft engines. The lattice misfit between the γ and γ′ phases results in internal stresses, which significantly influence the deformation and creep behavior of the material. Large-scale atomistic simulations that are often used to enhance our understanding of the deformation mechanisms in such materials must accurately account for such misfit stresses. In this work, we compare the internal stresses in both idealized and experimentally-informed, i.e., more realistic, γ/γ′ microstructures. The idealized samples are generated by assuming, as is frequently done, a periodic arrangement of cube-shaped γ′ particles with planar γ/γ′ interfaces. The experimentally-informed samples are generated from two different sources to produce three different samples—the scanning electron microscopy micrograph-informed quasi-2D atomistic sample and atom probe tomography-informed stoichiometric and non-stoichiometric atomistic samples. Additionally, we compare the stress state of an idealized embedded cube microstructure with finite element simulations incorporating 3D periodic boundary conditions. Subsequently, we study the influence of the resulting stress state on the evolution of dislocation loops in the different samples. The results show that the stresses in the atomistic and finite element simulations are almost identical. Furthermore, quasi-2D boundary conditions lead to a significantly different stress state and, consequently, different evolution of the dislocation loop, when compared to samples with fully 3D boundary conditions. PMID:28772453

Changes in employers' image of ideal dentists and managers in the Swedish public dental sector.

PubMed

Franzén, Cecilia; Söderfeldt, Björn

2002-10-01

Earlier studies have shown that employers are keen to have employees whose attitudinal and behavioral traits are consistent with the employers' ideology. One way of ascertaining the image of ideal individuals is to analyze the required qualifications in job advertisements. The aim of this study was to explore possible changes in the employers' view of the ideal manager and dentist in the Swedish Public Dental Health Service (PDHS). The study investigated the kinds and frequencies of manifestly required qualifications concerning vacancies in the PDHS from January 1990 to December 1998. All job advertisements intended for dentists and managers on different hierarchical levels in general dentistry were included (n = 1152); 5705 qualification demands were analyzed by content analysis permitting quantitative descriptions of the textual material as well as an analysis of the underlying characteristics over time. The study indicates that, for dentists, dental professional qualifications or qualifications in accordance with the official objective of dental care were insufficient. While requests for qualifications relating to the economic organizational goals of the PDHS increased during the latter part of the period under study, requests relating to the dental profession decreased. For managers, too, the demands for dental professional qualifications had decreased at the end of the studied period compared to the demands for managerial qualifications and non-professional qualifications, which had increased. In conclusion, the job advertisement portrays the ideal dentist and manager primarily as an economic organizational asset.

Perceived social pressures and the internalization of the mesomorphic ideal: The role of drive for muscularity and autonomy in physically active men.

PubMed

Edwards, Christian; Tod, David; Molnar, Gyozo; Markland, David

2016-03-01

We examined if there were both direct and indirect relationships (via the drive for muscularity) between the perceived pressure to be muscular and internalization of the mesomorphic ideal, and if autonomy moderates these relationships in physically active men. A sample of 330 men, who were undergraduate students studying sport, completed the Behavioral Regulation in Exercise Questionnaire-2, the Mesomorphic Ideal Internalization subscale of the revised male version Sociocultural Attitudes Toward Appearance Questionnaire, the Perceived Sociocultural Pressure Scale-Modified, and the Drive for Muscularity Scale Attitudes subscale. Perceived pressure predicted internalization directly, and indirectly through the drive for muscularity. The direct relationship between pressure and internalization was weaker under higher levels of autonomy. The indirect path, via drive for muscularity, was stronger under higher levels of autonomy. These results provide insights into why men vary in the degree to which they internalize pressure to develop a mesomorphic ideal, supporting further examination of autonomy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibitive Effect of Molybdate Ions on the Electrochemical Behavior of Steel Rebar in Simulated Concrete Pore Solution

NASA Astrophysics Data System (ADS)

Bensabra, Hakim; Franczak, Agnieszka; Aaboubi, Omar; Azzouz, Noureddine; Chopart, Jean-Paul

2017-01-01

Several compounds tested as corrosion inhibitors have proven to possess good effectiveness in protection of steel rebar in concrete. However, most of them are considered as pollutant compounds, which limits their use. The aim of this work is to investigate the inhibitive effect of sodium molybdate, which is considered as a nonpollutant compound, against pitting corrosion of steel rebar in simulated concrete pore solution. Corrosion behaviors of steel in different solutions were studied by means of corrosion potential, potentiodynamic polarization, and electrochemical impedance spectroscopy. The results indicate that the addition of sodium molybdate to the chlorinated solution decreases significantly the corrosion rate of steel. Due to its passivating character, the sodium molybdate inhibitor promotes the formation of a stable passive layer on the surface of steel, acting as a physical barrier against chloride ions, on one hand, and consolidating the passivation mechanism of steel, on the other. The optimal inhibition rate is given by the concentration of molybdate ions, corresponding to a [MoO4 2-]/[Cl-] that is equal to 0.5.

Gender-typing of leadership: evaluations of real and ideal managers.

PubMed

Cuadrado, Isabel; García-Ael, Cristina; Molero, Fernando

2015-04-01

This research focuses on female underrepresentation in managerial positions. Specifically, two studies examine gender-typing for managerial roles in Spain using ratings for real and ideal managers. In addition, we analyse the existence of same-gender bias on evaluations of the behavior of actual leaders. In the first study, 195 Spanish workers evaluate the extent to which gender-stereotypical traits are important for becoming a successful middle manager in three conditions (female managers, male managers, and managers in general). In the second study, we explore the degree to which the behavior of real Spanish managers is gender-typed and the existence of same-gender bias on leadership styles - transformational, transactional and avoidant/passive - and on leadership outcomes - effectiveness, extra effort and satisfaction - from the perspective of subordinates (N = 605). Overall, the results demonstrate that masculine characteristics were rated as more important than feminine characteristics for managerial positions, and they were more often assigned to male managers than to female managers. Unexpectedly, this manager-male association is stronger among female participants than among male participants. Our findings also demonstrate that women subordinates evaluate their same-sex supervisors more favorably in transformational leadership, effectiveness, and extra effort. The negative consequences derived from gender-typing managerial positions are highlighted according to the role congruity theory of prejudice toward female leaders. The positive effects of in-group female bias on behavior ratings are also noted. The mixed implications of these results for women's advancement to leadership positions are discussed. © 2015 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Computer modeling of the mechanical behavior of composites -- Interfacial cracks in fiber-reinforced materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmauder, S.; Haake, S.; Mueller, W.H.

Computer modeling of materials and especially modeling the mechanical behavior of composites became increasingly popular in the past few years. Among them are examples of micromechanical modeling of real structures as well as idealized model structures of linear elastic and elasto-plastic material response. In this paper, Erdogan`s Integral Equation Method (IEM) is chosen as an example for a powerful method providing principle insight into elastic fracture mechanical situations. IEM or, alternatively, complex function techniques sometimes even allow for deriving analytical solutions such as in the case of a circumferential crack along a fiber/matrix interface. The analytical formulae of this interfacemore » crack will be analyzed numerically and typical results will be presented graphically.« less

Influence of Dy in solid solution on the degradation behavior of binary Mg-Dy alloys in cell culture medium.

PubMed

Yang, Lei; Ma, Liangong; Huang, Yuanding; Feyerabend, Frank; Blawert, Carsten; Höche, Daniel; Willumeit-Römer, Regine; Zhang, Erlin; Kainer, Karl Ulrich; Hort, Norbert

2017-06-01

Rare earth element Dy is one of the promising alloying elements for magnesium alloy as biodegradable implants. To understand the effect of Dy in solid solution on the degradation of Mg-Dy alloys in simulated physiological conditions, the present work studied the microstructure and degradation behavior of Mg-Dy alloys in cell culture medium. It is found the corrosion resistance enhances with the increase of Dy content in solid solution in Mg. This can be attributed to the formation of a relatively more corrosion resistant Dy-enriched film which decreases the anodic dissolution of Mg. Copyright © 2017 Elsevier B.V. All rights reserved.

The place of the ideal observer in medical ethics.

PubMed

Churchill, L R

1983-01-01

The idea of an ideal observer is frequently employed in ethical reasoning and has recently been introduced into medical ethics. The contemporary use of this idea, however, is deeply flawed. It ignores important social and personal dimensions of ethics. By espousing a perspective of observation removed from history and community, the ideal observer notion encourages a pretense of objectivity and overlooks the distortions of distance. If taken seriously as a model for choice, the ideal observer is incoherent, as it dispenses with the concrete moral agent and the locus of choice. Adam Smith's 'impartial spectator' is examined as a more adequate statement of the need for appreciating diverse perspectives in ethical choices.

Quantifying ataxia: ideal trajectory analysis--a technical note

NASA Technical Reports Server (NTRS)

McPartland, M. D.; Krebs, D. E.; Wall, C. 3rd

2000-01-01

We describe a quantitative method to assess repeated stair stepping stability. In both the mediolateral (ML) and anterioposterior (AP) directions, the trajectory of the subject's center of mass (COM) was compared to an ideal sinusoid. The two identified sinusoids were unique in each direction but coupled. Two dimensionless numbers-the mediolateral instability index (IML) and AP instability index (IAP)-were calculated using the COM trajectory and ideal sinusoids for each subject with larger index values resulting from less stable performance. The COM trajectories of nine nonimpaired controls and six patients diagnosed with unilateral or bilateral vestibular labyrinth hypofunction were analyzed. The average IML and IAP values of labyrinth disorder patients were respectively 127% and 119% greater than those of controls (p<0.014 and 0.006, respectively), indicating that the ideal trajectory analysis distinguishes persons with labyrinth disorder from those without. The COM trajectories also identify movement inefficiencies attributable to vestibulopathy.

An Ideal Remedial Reading Program.

ERIC Educational Resources Information Center

Boettcher, Judith A.

An ideal secondary level remedial reading program would be based on the philosophy that both freedom and structure are required, that learning demands involvement and feedback, and that success breeds success. Such programs should be structured (i.e., based on clearly defined content and a clearly designated mode of presentation). There are many…

Competitiveness as a moderator of the relation between appearance-related factors and disordered eating behaviors.

PubMed

Schleien, Jenna L; Bardone-Cone, Anna M

2016-06-01

The present study examined competitiveness as a moderator of the relationships between appearance-related factors (i.e., thin-ideal internalization, appearance contingent self-worth) and disordered eating behaviors (i.e., dieting, excessive exercise). Participants were 441 undergraduate females for cross-sectional analyses, with 237 also contributing data longitudinally, 1 year later. Results showed that, in a model including thin-ideal internalization and appearance contingent self-worth and their interactions with competitiveness, thin-ideal internalization (but not appearance contingent self-worth) interacted with competitiveness to identify concurrent levels of both dieting and excessive exercise. Individuals high in both thin-ideal internalization and competitiveness exhibited the highest levels of concurrent dieting and excessive exercise. After controlling for baseline levels of the dependent variables, neither appearance-related factor interacted with competitiveness to predict dieting or excessive exercise. These findings suggest that individuals who are both competitive and accept and strive to achieve the thin ideal may be at risk for disordered eating behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Unified Theory of Non-Ideal Gas Lattice Boltzmann Models

NASA Technical Reports Server (NTRS)

Luo, Li-Shi

1998-01-01

A non-ideal gas lattice Boltzmann model is directly derived, in an a priori fashion, from the Enskog equation for dense gases. The model is rigorously obtained by a systematic procedure to discretize the Enskog equation (in the presence of an external force) in both phase space and time. The lattice Boltzmann model derived here is thermodynamically consistent and is free of the defects which exist in previous lattice Boltzmann models for non-ideal gases. The existing lattice Boltzmann models for non-ideal gases are analyzed and compared with the model derived here.

Hispanic maternal influences on daughters' unhealthy weight control behaviors: The role of maternal acculturation, adiposity, and body image disturbances.

PubMed

Olvera, Norma; Matthews-Ewald, Molly R; McCarley, Kendall; Scherer, Rhonda; Posada, Alexandria

2016-12-01

This study examined whether maternal adiposity, acculturation, and perceived-ideal body size discrepancy for daughters were associated with daughters' engagement in unhealthy weight control behaviors. A total of 97 Hispanic mother-daughter dyads completed surveys, rated a figure scale, and had their height, weight, and adiposity assessed. Mothers (M age =39.00, SD=6.20 years) selected larger ideal body sizes for their daughters (M age =11.12, SD=1.53 years) than their daughters selected for themselves. Mothers had a smaller difference between their perception of their daughters' body size and ideal body size compared to the difference between their daughters' selection of their perceived and ideal body size. More acculturated mothers and those mothers with larger waist-to-hip ratios were more likely to have daughters who engaged in unhealthy weight control behaviors. These findings highlight the relevant role that maternal acculturation and adiposity may have in influencing daughters' unhealthy weight control behaviors. Published by Elsevier Ltd.

Electrochemical behavior of lead alloys in sulfuric and phosphoric acid solutions

NASA Astrophysics Data System (ADS)

Paleska, I.; Pruszkowska-Drachal, R.; Kotowski, J.; Dziudzi, A.; Milewski, J. D.; Kopczyk, M.; Czerwiński, A.

The electrochemical behavior of lead, lead-antimony, and lead-calcium-aluminium-tin alloys has been studied in solutions containing various concentrations of sulfuric and phosphoric acids. The dependence of these electrode processes on some experimental conditions (mainly sweep rate and potential range) has been studied. The measurements were performed using a cyclic voltammetry technique. The study and the analysis of the morphology of alloys have been performed using a scanning electron microscope (SEM). Cyclic voltammograms of the lead-antimony alloy electrodes, similarly to pure lead electrode, also show the "anodic excursion" peak under some experimental conditions. Well defined current waves, corresponding to the oxidation and reduction processes of Sb, are observed, if the alloy surface is freshly abraded. The oxidation of antimony starts at potentials at which the formation of PbO takes place. The peak current of Sb oxidation reaction decreases during successive cycles, suggesting that Sb dissolves from the alloy surface during the first CV sweeps. Another explanation for this effect might be the formation of a PbSO 4 selective membrane.

The Paperless Solution

NASA Technical Reports Server (NTRS)

2001-01-01

REI Systems, Inc. developed a software solution that uses the Internet to eliminate the paperwork typically required to document and manage complex business processes. The data management solution, called Electronic Handbooks (EHBs), is presently used for the entire SBIR program processes at NASA. The EHB-based system is ideal for programs and projects whose users are geographically distributed and are involved in complex management processes and procedures. EHBs provide flexible access control and increased communications while maintaining security for systems of all sizes. Through Internet Protocol- based access, user authentication and user-based access restrictions, role-based access control, and encryption/decryption, EHBs provide the level of security required for confidential data transfer. EHBs contain electronic forms and menus, which can be used in real time to execute the described processes. EHBs use standard word processors that generate ASCII HTML code to set up electronic forms that are viewed within a web browser. EHBs require no end-user software distribution, significantly reducing operating costs. Each interactive handbook simulates a hard-copy version containing chapters with descriptions of participants' roles in the online process.

Chemical Laws, Idealization and Approximation

ERIC Educational Resources Information Center

Tobin, Emma

2013-01-01

This paper examines the notion of laws in chemistry. Vihalemm ("Found Chem" 5(1):7-22, 2003) argues that the laws of chemistry are fundamentally the same as the laws of physics they are all "ceteris paribus" laws which are true "in ideal conditions". In contrast, Scerri (2000) contends that the laws of chemistry are…

Examining the influence of actual-ideal self-discrepancies, depression, and escapism, on pathological gaming among massively multiplayer online adolescent gamers.

PubMed

Li, Dongdong; Liau, Albert; Khoo, Angeline

2011-09-01

This study examined whether actual-ideal self-discrepancy (AISD) is related to pathological gaming through escapism as a means of reducing depression for adolescent massively multiplayer online gamers. A Discrepancy-reduction Motivation model of pathological video gaming was tested. A survey was conducted on 161 adolescent gamers from secondary schools. Two mediation effects were tested using path analysis: (a) depression would mediate the relationship between AISDs and escapism, and (b) escapism would mediate the relationship between depression and pathological gaming. Results support the hypotheses stated above. The indirect effects of both AISD and depression were significant on pathological gaming. AISD and escapism also had direct effects on pathological gaming. The present study suggests that pathological behaviors may be over-regulated coping strategies of approaching the ideal self and avoiding the actual self.

Delivering ideal employee experiences.

PubMed

Weiss, Marjorie D; Tyink, Steve; Kubiak, Curt

2009-05-01

Employee-centric strategies have moved from employee satisfaction and brand awareness to employee "affinity" or "attachment." In today's marketplace, occupational health nurses understand that differentiation (i.e., the perception of uniqueness) is the direct result of superior employee interactions, which lead to better employee care, enduring employee relationships, loyal employees, and satisfied employers. What drives employees to occupational health nurse attachment? The answer is a passion for rising above the competition to create ideal employee experiences.

Robotic kidney transplantation with regional hypothermia: evolution of a novel procedure utilizing the IDEAL guidelines (IDEAL phase 0 and 1).

PubMed

Menon, Mani; Abaza, Ronney; Sood, Akshay; Ahlawat, Rajesh; Ghani, Khurshid R; Jeong, Wooju; Kher, Vijay; Kumar, Ramesh K; Bhandari, Mahendra

2014-05-01

Surgical innovation is essential for progress of surgical science, but its implementation comes with potential harms during the learning phase. The Balliol Collaboration has recommended a set of guidelines (Innovation, Development, Exploration, Assessment, Long-term study [IDEAL]) that permit innovation while minimizing complications. To utilize the IDEAL model of surgical innovation in the development of a novel surgical technique, robotic kidney transplantation (RKT) with regional hypothermia, and describe the process of discovery and development. Phase 0 (simulation) studies included the establishment of techniques for pelvic cooling, graft placement in a robotic prostatectomy model, and simulation of the RKT procedure in a cadaveric model. Phase 1 (innovation) studies began in January 2013 and involved treatment of a highly selective small group of patients (n=7), using the principles utilized in the phase 0 studies, at a tertiary referral center. IDEAL model implementation in the development of RKT with regional hypothermia. For phase 0 studies, the outcomes evaluated included pelvic and body temperature measurements, and technical feasibility assessment. The primary outcome during phase 1 was post-transplant graft function. Other outcomes measured were operative and ischemic times, perioperative complications, and intracorporeal graft surface temperature. Phase 0 (simulation phase): Pelvic cooling to 15-20(o)C was achieved reproducibly. Using the surgical approach developed for robotic radical prostatectomy, vascular and ureterovesical anastomoses could be done without redocking the robot. Phase 1 (innovation phase): All patients underwent live-donor RKT in the lithotomy position. All grafts functioned immediately. Mean console, anastomotic, and warm ischemia times were 154 min, 29 min, and 2 min, respectively. One patient was re-explored on postoperative day 1. Adherence to the IDEAL guidelines put forth by the Balliol Collaboration provided a practical

Behavior of pure gallium in water and various saline solutions.

PubMed

Horasawa, N; Nakajima, H; Takahashi, S; Okabe, T

1997-12-01

This study investigated the chemical stability of pure gallium in water and saline solutions in order to obtain fundamental knowledge about the corrosion mechanism of gallium-based alloys. A pure gallium plate (99.999%) was suspended in 50 mL of deionized water, 0.01%, 0.1% or 1% NaCl solution at 24 +/- 2 degrees C for 1, 7, or 28 days. The amounts of gallium released into the solutions were determined by atomic absorption spectrophotometry. The surfaces of the specimens were examined after immersion by x-ray diffractometry (XRD) and x-ray photoelectron spectroscopy (XPS). In the solutions containing 0.1% or more NaCl, the release of gallium ions into the solution was lowered when compared to deionized water after 28-day immersion. Gallium oxide monohydroxide was found by XRD on the specimens immersed in deionized water after 28-day immersion. XPS indicated the formation of gallium oxide/hydroxide on the specimens immersed in water or 0.01% NaCl solution. The chemical stability of pure solid gallium was strongly affected by the presence of Cl- ions in the aqueous solution.

Sharp Truncation of an Electric Field: An Idealized Model That Warrants Caution

ERIC Educational Resources Information Center

Tu, Hong; Zhu, Jiongming

2016-01-01

In physics, idealized models are often used to simplify complex situations. The motivation of the idealization is to make the real complex system tractable by adopting certain simplifications. In this treatment some unnecessary, negligible aspects are stripped away (so-called Aristotelian idealization), or some deliberate distortions are involved…

Neurocultural evidence that ideal affect match promotes giving

PubMed Central

Park, BoKyung; Blevins, Elizabeth; Knutson, Brian

2017-01-01

Abstract Why do people give to strangers? We propose that people trust and give more to those whose emotional expressions match how they ideally want to feel (“ideal affect match”). European Americans and Koreans played multiple trials of the Dictator Game with recipients who varied in emotional expression (excited, calm), race (White, Asian) and sex (male, female). Consistent with their culture’s valued affect, European Americans trusted and gave more to excited than calm recipients, whereas Koreans trusted and gave more to calm than excited recipients. These findings held regardless of recipient race and sex. We then used fMRI to probe potential affective and mentalizing mechanisms. Increased activity in the nucleus accumbens (associated with reward anticipation) predicted giving, as did decreased activity in the right temporo-parietal junction (rTPJ; associated with reduced belief prediction error). Ideal affect match decreased rTPJ activity, suggesting that people may trust and give more to strangers whom they perceive to share their affective values. PMID:28379542

Reported Effects of Masculine Ideals on Gay Men.

PubMed

Sánchez, Francisco J; Greenberg, Stefanie T; Liu, William Ming; Vilain, Eric

2009-01-01

This exploratory study used consensual qualitative research methodology (Hill et al., 2005) to analyze what gay men associate with masculinity and femininity, how they feel masculine ideals affect their self-image, and how masculine ideals affect their same-sex relationships. Written responses were collected from 547 self-identified gay men in the U.S. via an Internet-based survey. Findings supported previous reports that perceptions of gender roles among gay men appear based on masculine and feminine stereotypes. Additionally, more adverse versus positive effects on self-image and same-sex romantic relationships were reported including difficulty being emotional and affectionate, pressure to be physically attractive, and pressure to appear masculine in order to be accepted by society and to be seen as desirable by other gay men. While research on gay men's experience with masculinity continues, psychologists should consider the possible influence of traditional masculine ideals when conceptualizing their gay male clients.

Reported Effects of Masculine Ideals on Gay Men

PubMed Central

Sánchez, Francisco J.; Greenberg, Stefanie T.; Liu, William Ming; Vilain, Eric

2010-01-01

This exploratory study used consensual qualitative research methodology (Hill et al., 2005) to analyze what gay men associate with masculinity and femininity, how they feel masculine ideals affect their self-image, and how masculine ideals affect their same-sex relationships. Written responses were collected from 547 self-identified gay men in the U.S. via an Internet-based survey. Findings supported previous reports that perceptions of gender roles among gay men appear based on masculine and feminine stereotypes. Additionally, more adverse versus positive effects on self-image and same-sex romantic relationships were reported including difficulty being emotional and affectionate, pressure to be physically attractive, and pressure to appear masculine in order to be accepted by society and to be seen as desirable by other gay men. While research on gay men’s experience with masculinity continues, psychologists should consider the possible influence of traditional masculine ideals when conceptualizing their gay male clients. PMID:20628534

Simplified thermochemistry of oxygen in lithium and sodium for liquid metal cooling systems

NASA Technical Reports Server (NTRS)

Tower, L. K.

1972-01-01

Plots of oxygen chemical potential against composition of lithium-oxygen solutions and sodium-oxygen solutions for a range of temperature were constructed. For each liquid metal two such plots were prepared. For one plot ideal solution behavior was assumed. For the other plot, existing solubility limit data for oxygen in the liquid metal were used to determine a first-order term for departure from ideality. The use of the plots in evaluating the oxygen gettering capability of refractory metals in liquid metal cooling systems is illustrated by a simple example involving lithium, oxygen, and hafnium.

Tempting Fate or Inviting Happiness? Unrealistic idealization prevents the decline of marital satisfaction

PubMed Central

Murray, Sandra L.; Griffin, Dale W.; Derrick, Jaye L.; Harris, Brianna; Aloni, Maya; Leder, Sadie

2014-01-01

The authors examine whether unrealistically viewing a romantic partner as the image of one’s ideal partner accelerates or slows declines in marital satisfaction among newlyweds. A longitudinal study linked unrealistic idealization at the point of marriage to changes in satisfaction over the first three years of marriage. Overall, satisfaction declined markedly, consistent with past research. However, seeing a less-than-ideal partner as a reflection of one’s ideals predicted a certain level of immunity to the corrosive effects of time: People who initially idealized their partner highly experienced no declines in satisfaction. The obtained benefits of idealization remained in analyses that separately controlled for the positivity of partner perceptions and the possibility that better adjusted people might be in better relationships. PMID:21467549

An Onsager Singularity Theorem for Turbulent Solutions of Compressible Euler Equations

NASA Astrophysics Data System (ADS)

Drivas, Theodore D.; Eyink, Gregory L.

2017-12-01

We prove that bounded weak solutions of the compressible Euler equations will conserve thermodynamic entropy unless the solution fields have sufficiently low space-time Besov regularity. A quantity measuring kinetic energy cascade will also vanish for such Euler solutions, unless the same singularity conditions are satisfied. It is shown furthermore that strong limits of solutions of compressible Navier-Stokes equations that are bounded and exhibit anomalous dissipation are weak Euler solutions. These inviscid limit solutions have non-negative anomalous entropy production and kinetic energy dissipation, with both vanishing when solutions are above the critical degree of Besov regularity. Stationary, planar shocks in Euclidean space with an ideal-gas equation of state provide simple examples that satisfy the conditions of our theorems and which demonstrate sharpness of our L 3-based conditions. These conditions involve space-time Besov regularity, but we show that they are satisfied by Euler solutions that possess similar space regularity uniformly in time.

Critical Thinking and Educational Ideal

ERIC Educational Resources Information Center

Liu, Qian

2007-01-01

Critical thinking, as an educational trend, has been much discussed and proposed nowadays. In this paper, an analysis is made on the gap between our present educational practice and educational ideal from three different aspects, that is, the content, the manner and the one-sidedness of our teaching. It's observed that there is still a long way to…

Turboprop IDEAL: a motion-resistant fat-water separation technique.

PubMed

Huo, Donglai; Li, Zhiqiang; Aboussouan, Eric; Karis, John P; Pipe, James G

2009-01-01

Suppression of the fat signal in MRI is very important for many clinical applications. Multi-point water-fat separation methods, such as IDEAL (Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation), can robustly separate water and fat signal, but inevitably increase scan time, making separated images more easily affected by patient motions. PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) and Turboprop techniques offer an effective approach to correct for motion artifacts. By combining these techniques together, we demonstrate that the new TP-IDEAL method can provide reliable water-fat separation with robust motion correction. The Turboprop sequence was modified to acquire source images, and motion correction algorithms were adjusted to assure the registration between different echo images. Theoretical calculations were performed to predict the optimal shift and spacing of the gradient echoes. Phantom images were acquired, and results were compared with regular FSE-IDEAL. Both T1- and T2-weighted images of the human brain were used to demonstrate the effectiveness of motion correction. TP-IDEAL images were also acquired for pelvis, knee, and foot, showing great potential of this technique for general clinical applications.

Hybrid normed ideal perturbations of n-tuples of operators I

NASA Astrophysics Data System (ADS)

Voiculescu, Dan-Virgil

2018-06-01

In hybrid normed ideal perturbations of n-tuples of operators, the normed ideal is allowed to vary with the component operators. We begin extending to this setting the machinery we developed for normed ideal perturbations based on the modulus of quasicentral approximation and an adaptation of our non-commutative generalization of the Weyl-von Neumann theorem. For commuting n-tuples of hermitian operators, the modulus of quasicentral approximation remains essentially the same when Cn- is replaced by a hybrid n-tuple Cp1,…- , … , Cpn- , p1-1 + ⋯ + pn-1 = 1. The proof involves singular integrals of mixed homogeneity.

Health care market deviations from the ideal market.

PubMed

Mwachofi, Ari; Al-Assaf, Assaf F

2011-08-01

A common argument in the health policy debate is that market forces allocate resources efficiently in health care, and that government intervention distorts such allocation. Rarely do those making such claims state explicitly that the market they refer to is an ideal in economic theory which can only exist under very strict conditions. This paper explores the strict conditions necessary for that ideal market in the context of health care as a means of examining the claim that market forces do allocate resources efficiently in health care.

Idealness and similarity in goal-derived categories: a computational examination.

PubMed

Voorspoels, Wouter; Storms, Gert; Vanpaemel, Wolf

2013-02-01

The finding that the typicality gradient in goal-derived categories is mainly driven by ideals rather than by exemplar similarity has stood uncontested for nearly three decades. Due to the rather rigid earlier implementations of similarity, a key question has remained--that is, whether a more flexible approach to similarity would alter the conclusions. In the present study, we evaluated whether a similarity-based approach that allows for dimensional weighting could account for findings in goal-derived categories. To this end, we compared a computational model of exemplar similarity (the generalized context model; Nosofsky, Journal of Experimental Psychology. General 115:39-57, 1986) and a computational model of ideal representation (the ideal-dimension model; Voorspoels, Vanpaemel, & Storms, Psychonomic Bulletin & Review 18:1006-114, 2011) in their accounts of exemplar typicality in ten goal-derived categories. In terms of both goodness-of-fit and generalizability, we found strong evidence for an ideal approach in nearly all categories. We conclude that focusing on a limited set of features is necessary but not sufficient to account for the observed typicality gradient. A second aspect of ideal representations--that is, that extreme rather than common, central-tendency values drive typicality--seems to be crucial.

Umbilical hernia repair with mesh: identifying effectors of ideal outcomes.

PubMed

Colavita, Paul D; Belyansky, Igor; Walters, Amanda L; Zemlyak, Alla Y; Lincourt, Amy E; Heniford, B Todd; Augenstein, Vedra A

2014-09-01

Quality of life has become an important focus for improvement in hernia repair. The International Hernia Mesh Registry was queried. The Carolinas Comfort Scale quantitated quality of life at 1-month, 6-month, and annual follow-up. Scores of 0 (completely asymptomatic) in all categories without recurrence defined an ideal outcome. The analysis consisted of 363 umbilical hernia repairs; 18.7% were laparoscopic. Demographics included age of 51.5 ± 13.8 years, 24.5% were female, and the average body mass index was 30.63 ± 5.9 kg/m(2). Mean defect size was 4.3 ± 3.1 cm(2). Mean follow-up was 18.2 months. Absent/minimal preoperative symptoms were predictive of ideal outcome at all time points and increasing age was predictive at 6 months and 1 year. At 6 months, the use of fixation sutures alone versus tacks (odds ratio 14.1) predicted ideal outcome. Ideal outcomes are dependent on both patient-specific and operative factors. The durable, ideal outcome in umbilical hernia repair is most likely in an older, asymptomatic patient who undergoes mesh fixation with permanent suture. Copyright © 2014 Elsevier Inc. All rights reserved.

What Do College Students Want? A Prioritization of Instructional Behaviors and Characteristics

ERIC Educational Resources Information Center

Goldman, Zachary W.; Cranmer, Gregory A.; Sollitto, Michael; Labelle, Sara; Lancaster, Alexander L.

2017-01-01

Guided by Rhetorical and Relational Goals Theory, this study examined college students' preferences for effective teaching behaviors and characteristics. Students (n = 209) articulated qualities in their ideal instructor by prioritizing 10 instructional behaviors and characteristics from the rhetorical and relational traditions (assertive,…

Ideal GLM-MHD: About the entropy consistent nine-wave magnetic field divergence diminishing ideal magnetohydrodynamics equations

NASA Astrophysics Data System (ADS)

Derigs, Dominik; Winters, Andrew R.; Gassner, Gregor J.; Walch, Stefanie; Bohm, Marvin

2018-07-01

The paper presents two contributions in the context of the numerical simulation of magnetized fluid dynamics. First, we show how to extend the ideal magnetohydrodynamics (MHD) equations with an inbuilt magnetic field divergence cleaning mechanism in such a way that the resulting model is consistent with the second law of thermodynamics. As a byproduct of these derivations, we show that not all of the commonly used divergence cleaning extensions of the ideal MHD equations are thermodynamically consistent. Secondly, we present a numerical scheme obtained by constructing a specific finite volume discretization that is consistent with the discrete thermodynamic entropy. It includes a mechanism to control the discrete divergence error of the magnetic field by construction and is Galilean invariant. We implement the new high-order MHD solver in the adaptive mesh refinement code FLASH where we compare the divergence cleaning efficiency to the constrained transport solver available in FLASH (unsplit staggered mesh scheme).

Breaking the cycle: The effects of role model performance and ideal leadership self-concepts on abusive supervision spillover.

PubMed

Tu, Min-Hsuan; Bono, Joyce E; Shum, Cass; LaMontagne, Liva

2018-03-19

Building on identity theories and social learning theory, we test the notion that new leaders will model the abusive behaviors of their superiors only under certain conditions. Specifically, we hypothesize that new leaders will model abusive supervisory behaviors when (a) abusive superiors are perceived to be competent, based on the performance of their teams and (b) new leaders' ideal leadership self-concepts are high on tyranny or low on sensitivity. Results of an experiment in which we manipulated abusive supervisory behaviors using a professional actor, and created a role change where 93 individuals moved from team member to team leader role, generally support our hypotheses. We found the strongest association between abuse exposure and new leader abuse under conditions where the abusive superior's team performed well and the new team leaders' self-concepts showed low concern for others. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Teachers' Ethnotheories of the "Ideal Student" in Five Western Cultures

ERIC Educational Resources Information Center

Harkness, Sara; Blom, Marjolijn; Oliva, Alfredo; Moscardino, Ughetta; Zylicz, Piotr Olaf; Bermudez, Moises Rios; Feng, Xin; Carrasco-Zylicz, Agnieszka; Axia, Giovanna; Super, Charles M.

2007-01-01

This paper explores teachers' ethnotheories of the "ideal student" in five western societies: Italy, The Netherlands, Poland, Spain, and the US. Quantitative and qualitative methods are used to derive culture-specific profiles of the "ideal student" as described by kindergarten and primary school teachers in semi-structured…

Quantification of non-ideal explosion violence with a shock tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, Scott I; Hill, Larry G

There is significant interest in quantifying the blast violence associated with various nonideal explosions. Such data is essential to evaluate the damage potential of both explosive cookoff and terrorist explosive scenarios. We present a technique designed to measure the source energy associated with a non-ideal, asymmetrical, and three-dimensional explosion. A tube is used to confine and focus energy from a blast event into a one-dimensional, quasi-planar shock front. During propagation along the length of the tube, the wave is allowed to shocksteepen into a more ideal form. Pressure transducers then measure the shock overpressure as a function of the distancemore » from the source. One-dimensional blast scaling theory allows calculation of the source energy from this data. This small-scale test method addresses cost and noise concerns as well as boosting and symmetry issues associated with large-scale, three-dimensional, blast arena tests. Results from both ideal explosives and non-ideal explosives are discussed.« less

Modeling NAPL dissolution from pendular rings in idealized porous media

NASA Astrophysics Data System (ADS)

Huang, Junqi; Christ, John A.; Goltz, Mark N.; Demond, Avery H.

2015-10-01

The dissolution rate of nonaqueous phase liquid (NAPL) often governs the remediation time frame at subsurface hazardous waste sites. Most formulations for estimating this rate are empirical and assume that the NAPL is the nonwetting fluid. However, field evidence suggests that some waste sites might be organic wet. Thus, formulations that assume the NAPL is nonwetting may be inappropriate for estimating the rates of NAPL dissolution. An exact solution to the Young-Laplace equation, assuming NAPL resides as pendular rings around the contact points of porous media idealized as spherical particles in a hexagonal close packing arrangement, is presented in this work to provide a theoretical prediction for NAPL-water interfacial area. This analytic expression for interfacial area is then coupled with an exact solution to the advection-diffusion equation in a capillary tube assuming Hagen-Poiseuille flow to provide a theoretical means of calculating the mass transfer rate coefficient for dissolution at the NAPL-water interface in an organic-wet system. A comparison of the predictions from this theoretical model with predictions from empirically derived formulations from the literature for water-wet systems showed a consistent range of values for the mass transfer rate coefficient, despite the significant differences in model foundations (water wetting versus NAPL wetting, theoretical versus empirical). This finding implies that, under these system conditions, the important parameter is interfacial area, with a lesser role played by NAPL configuration.

Nonautonomous discrete bright soliton solutions and interaction management for the Ablowitz-Ladik equation.

PubMed

Yu, Fajun

2015-03-01

We present the nonautonomous discrete bright soliton solutions and their interactions in the discrete Ablowitz-Ladik (DAL) equation with variable coefficients, which possesses complicated wave propagation in time and differs from the usual bright soliton waves. The differential-difference similarity transformation allows us to relate the discrete bright soliton solutions of the inhomogeneous DAL equation to the solutions of the homogeneous DAL equation. Propagation and interaction behaviors of the nonautonomous discrete solitons are analyzed through the one- and two-soliton solutions. We study the discrete snaking behaviors, parabolic behaviors, and interaction behaviors of the discrete solitons. In addition, the interaction management with free functions and dynamic behaviors of these solutions is investigated analytically, which have certain applications in electrical and optical systems.

Axially Symmetric Brans-Dicke-Maxwell Solutions