WorldWideScience

Sample records for understand particle behavior

  1. Understanding bulk behavior of particulate materials from particle scale simulations

    Science.gov (United States)

    Deng, Xiaoliang

    Particulate materials play an increasingly significant role in various industries, such as pharmaceutical manufacturing, food, mining, and civil engineering. The objective of this research is to better understand bulk behaviors of particulate materials from particle scale simulations. Packing properties of assembly of particles are investigated first, focusing on the effects of particle size, surface energy, and aspect ratio on the coordination number, porosity, and packing structures. The simulation results show that particle sizes, surface energy, and aspect ratio all influence the porosity of packing to various degrees. The heterogeneous force networks within particle assembly under external compressive loading are investigated as well. The results show that coarse-coarse contacts dominate the strong network and coarse-fine contacts dominate the total network. Next, DEM models are developed to simulate the particle dynamics inside a conical screen mill (comil) and magnetically assisted impaction mixer (MAIM), both are important particle processing devices. For comil, the mean residence time (MRT), spatial distribution of particles, along with the collision dynamics between particles as well as particle and vessel geometries are examined as a function of the various operating parameters such as impeller speed, screen hole size, open area, and feed rate. The simulation results can help better understand dry coating experimental results using comil. For MAIM system, the magnetic force is incorporated into the contact model, allowing to describe the interactions between magnets. The simulation results reveal the connections between homogeneity of mixture and particle scale variables such as size of magnets and surface energy of non-magnets. In particular, at the fixed mass ratio of magnets to non-magnets and surface energy the smaller magnets lead to better homogeneity of mixing, which is in good agreement with previously published experimental results. Last but not

  2. Particles, contacts, bulk behavior

    NARCIS (Netherlands)

    Luding, Stefan; Tomas, J.

    2014-01-01

    Granular matter consists of discrete “particles”. These can be separate sand-grains, agglomerates (made of many primary particles), or solid materials like rock, composites, or metal-alloys—all with particulate inhomogeneous, possibly anisotropic micro-structure. Particles can be as small as

  3. Challenges in human behavior understanding

    NARCIS (Netherlands)

    Salah, A.A.; Gevers, T.; Sebe, N.; Vinciarelli, A.

    2010-01-01

    Recent advances in pattern recognition has allowed computer scientists and psychologists to jointly address automatic analysis of of human behavior via computers. The Workshop on Human Behavior Understanding at the International Conference on Pattern Recognition explores a number of different

  4. Understanding Licensing Behavior

    DEFF Research Database (Denmark)

    Cabaleiro, Goretti; Moreira, Solon; Reichstein, Toke

    The potential for rent dissipation has been argued to be the main cause of firms? licensing out behavior being stifled.However, this aspect has been scarcely studied empirically. We draw on rent dissipation arguments, and hypothesize that firms suffering from the not-invented-here (NIH) syndrome...

  5. Understanding Licensing Behavior

    DEFF Research Database (Denmark)

    Cabaleiro, Goretti; Moreira, Solon; Reichstein, Toke

    The potential for rent dissipation has been argued to be the main cause of firms? licensing out behavior being stifled.However, this aspect has been scarcely studied empirically. We draw on rent dissipation arguments, and hypothesize that firms suffering from the not-invented-here (NIH) syndrome,...

  6. Understanding Consumer Buying Behavior in Africa

    DEFF Research Database (Denmark)

    Kuada, John Ernest; Bujac, Andreea Ioana

    2017-01-01

    Recent economic growth trends in Africa have raised awareness among businesses about the attractiveness of its market potential. There is therefore an increasing academic interest in understanding the attitudes, preferences and behavior of African consumers. This chapter reviews some...

  7. Understanding behaviors in videos through behavior-specific dictionaries

    DEFF Research Database (Denmark)

    Ren, Huamin; Liu, Weifeng; Olsen, Søren Ingvor

    2018-01-01

    Understanding behaviors is the core of video content analysis, which is highly related to two important applications: abnormal event detection and action recognition. Dictionary learning, as one of the mid-level representations, is an important step to process a video. It has achieved state...

  8. Tracking Students' Understanding of the Particle Nature of Matter

    Science.gov (United States)

    Merritt, Joi Deshawn

    One reason students find it difficult to learn the particle model of matter is that traditional curriculum materials present concepts to students without helping them to develop these ideas. The How can I smell things from a distance? sixth grade chemistry unit takes the approach of building students' ideas through their construction and revision of models. Progress variables have been proposed as a means to address the need for curriculum and assessments that can help teachers' improve their practice as well as to inform both students and teachers about students' performance. Progress variables depict students' increasingly sophisticated conceptions of a specific construct during instruction. This study provides evidence that curriculum and assessment based on modern learning theories, can lead to the development of progress variables that are able to track middle school students' understanding of the particle nature of matter over time. This study used a progress variable to track student understanding of the particle nature of matter during the sixth grade chemistry unit. I describe the assessment system used to develop the progress variable for tracking students' development of particle model of matter during the sixth grade chemistry unit. A calibration study determined that the chemistry unit's assessments were reliable and valid measures of the particle model of matter progress variable. Further analysis revealed that the progress variable had to be modified such that the levels were more distinct. The modified progress variable was empirically validated so that it could be used to track students' understanding during instruction. Results indicate that a validated progress variable, linked to coherent curriculum and assessments can provide valid interpretations of students' knowledge of particular domain during instruction and that this progress variable is valid for students from varying populations and backgrounds. In addition, well-aligned curriculum and

  9. Understanding behaviors in videos through behavior-specific dictionaries

    DEFF Research Database (Denmark)

    Ren, Huamin; Liu, Weifeng; Olsen, Søren Ingvor

    2018-01-01

    Understanding behaviors is the core of video content analysis, which is highly related to two important applications: abnormal event detection and action recognition. Dictionary learning, as one of the mid-level representations, is an important step to process a video. It has achieved state...... scalability needs: A dictionary aimed at an abnormality detection purpose may misdetect normal behavior, which rarely happens in training datasets even though it may be very common in daily life. In contrast, a dictionary aimed at action recognition may misclassify a newcoming action category as an existing...... action. Therefore, our Behavior-Specific Dictionaries (BSDs) are constructed to solve these two applications through a unified framework. To the best of our knowledge, this is the first generalized dictionary algorithm that successfully handle with action recognition and abnormality detection...

  10. Understanding consumer decisions using behavioral economics.

    Science.gov (United States)

    Zandstra, Elizabeth H; Miyapuram, Krishna P; Tobler, Philippe N

    2013-01-01

    Consumers make many decisions in everyday life involving finances, food, and health. It is known from behavioral economics research that people are often driven by short-term gratification, that is, people tend to choose the immediate, albeit smaller reward. But choosing the delayed reward, that is, delaying the gratification, can actually be beneficial. How can we motivate consumers to resist the "now" and invest in their future, leading to sustainable or healthy habits? We review recent developments from behavioral and neuroimaging studies that are relevant for understanding consumer decisions. Further, we present results from our field research that examined whether we can increase the perceived value of a (delayed) environmental benefit using tailored communication, that is, change the way it is framed. More specifically, we investigated whether we can boost the value of an abstract, long-term "green" claim of a product by expressing it as a concrete, short-term benefit. This is a new application area for behavioral economics. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Human behavior-based particle swarm optimization.

    Science.gov (United States)

    Liu, Hao; Xu, Gang; Ding, Gui-Yan; Sun, Yu-Bo

    2014-01-01

    Particle swarm optimization (PSO) has attracted many researchers interested in dealing with various optimization problems, owing to its easy implementation, few tuned parameters, and acceptable performance. However, the algorithm is easy to trap in the local optima because of rapid losing of the population diversity. Therefore, improving the performance of PSO and decreasing the dependence on parameters are two important research hot points. In this paper, we present a human behavior-based PSO, which is called HPSO. There are two remarkable differences between PSO and HPSO. First, the global worst particle was introduced into the velocity equation of PSO, which is endowed with random weight which obeys the standard normal distribution; this strategy is conducive to trade off exploration and exploitation ability of PSO. Second, we eliminate the two acceleration coefficients c 1 and c 2 in the standard PSO (SPSO) to reduce the parameters sensitivity of solved problems. Experimental results on 28 benchmark functions, which consist of unimodal, multimodal, rotated, and shifted high-dimensional functions, demonstrate the high performance of the proposed algorithm in terms of convergence accuracy and speed with lower computation cost.

  12. Understanding the Irradiation Behavior of Zirconium Carbide

    Energy Technology Data Exchange (ETDEWEB)

    Motta, Arthur [Pennsylvania State Univ., University Park, PA (United States); Sridharan, Kumar [Univ. of Wisconsin, Madison, WI (United States); Morgan, Dane [Univ. of Wisconsin, Madison, WI (United States); Szlufarska, Izabela [Univ. of Wisconsin, Madison, WI (United States)

    2013-10-11

    -induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.

  13. Parsing anomalous versus normal diffusive behavior of bedload sediment particles

    Science.gov (United States)

    Fathel, Siobhan; Furbish, David; Schmeeckle, Mark

    2016-01-01

    Bedload sediment transport is the basic physical ingredient of river evolution. Formulae exist for estimating transport rates, but the diffusive contribution to the sediment flux, and the associated spreading rate of tracer particles, are not clearly understood. The start-and-stop motions of sediment particles transported as bedload on a streambed mimic aspects of the Einstein–Smoluchowski description of the random-walk motions of Brownian particles. Using this touchstone description, recent work suggests the presence of anomalous diffusion, where the particle spreading rate differs from the linear dependence with time of Brownian behavior. We demonstrate that conventional measures of particle spreading reveal different attributes of bedload particle behavior depending on details of the calculation. When we view particle motions over start-and-stop timescales obtained from high-speed (250 Hz) imaging of coarse-sand particles, high-resolution measurements reveal ballistic-like behavior at the shortest (10−2 s) timescale, followed by apparent anomalous behavior due to correlated random walks in transition to normal diffusion (>10−1 s) – similar to Brownian particle behavior but involving distinctly different physics. However, when treated as a ‘virtual plume’ over this timescale range, particles exhibit inhomogeneous diffusive behavior because both the mean and the variance of particle travel distances increase nonlinearly with increasing travel times, a behavior that is unrelated to anomalous diffusion or to Brownian-like behavior. Our results indicate that care is needed in suggesting anomalous behavior when appealing to conventional measures of diffusion formulated for ideal particle systems.

  14. Examination of Particle Behavior in Container on Multi-Particle Collision Damper

    Directory of Open Access Journals (Sweden)

    Yoshihiro Takahashi

    2015-08-01

    Full Text Available Recently, impact dampers have been used to decrease the vibrations of objects. One specific case of a damper is a container filled with many spherical particles. Compressive forces, frictional forces, and impacts are generated between particles and the wall. Therefore, it is important to clarify the flow conditions of particles in order to investigate the appropriate damping conditions. However, it is difficult to experimentally observe and to calculate the complex behavior of particles in such a container. In this study, the behaviors of particles in a container of a particle damper were examined through experiments using piezoelectric elements and simulations performed by the discrete element method (DEM. Many spherical particles fill a container. The container is made to periodically move in a horizontal direction. The relationships between the collision of particles with the wall and the voltage value from the piezoelectric element were examined. With these calculations, particle behaviors and particle conditions can be analyzed. The behaviors of simulated particles were similar to those of experimental results. From both results it is shown that an appropriate selection of the filling ratio and of particle size will lead to the effect of particles for damping.

  15. Action word understanding and overt motor behavior.

    Science.gov (United States)

    Dalla Volta, Riccardo; Gianelli, Claudia; Campione, Giovanna Cristina; Gentilucci, Maurizio

    2009-07-01

    Is the motor system involved in language processing? In order to clarify this issue, we carried out three behavioral experiments, using go-no-go and choice paradigms. In all the experiments, we used a semantic decision task with an early delivery of the go signal (during processing language material). Italian verbs expressing hand actions, foot actions or an abstract content served as stimuli. Participants executed intransitive (Experiment 1) or transitive (Experiment 2) actions with their right hand in response to the acoustic presentation of action-related verbs and refrained from responding to abstract verbs. The kinematics of the actions was slowed down by hand action-related verbs when compared with foot action-related verbs. In Experiment 3, hand-related and foot-related verbs were presented. Participants responded to hand-related and foot-related verbs with their hand and their foot (compatible condition) and in another block of trials they responded to hand-related and foot-related verbs with their foot and their hand (incompatible condition), respectively. In the compatible condition, the beginning of the action was faster, whereas the kinematics of the action was slower. The present findings suggest complete activation of verb-related motor programs during language processing. The data are discussed in support of the hypothesis that this complete activation is necessary requisite to understand the exact meaning of action words because goal and consequence of the actions are represented.

  16. Irradiation behaviors of coated fuel particles, (4)

    International Nuclear Information System (INIS)

    Fukuda, Kousaku; Kashimura, Satoru; Ogawa, Toru; Ikawa, Katsuichi; Iwamoto, Kazumi; Ishimoto, Kiyoshi

    1981-09-01

    Loose coated fuel particles prepared in confirmity to a preliminary design for the multi-purpose VHTR in fiscal 1972 - 1974 were irradiated by 73F - 12A capsule in JMTR. Main purpose for this irradiation experiment was to examine irradiation stability of the candidate TRISO coated fuel particles for the VHTR. Also the coated particles possessing low-density kernel (90%TD), highly anisotropic OLTI-PyC and ZrC coating layer were loaded with the candidate particles in this capsule. The coated particles were irradiated up to 1.5 x 10 21 n/cm 2 of fast neutron fluence (E > 0.18 MeV) and 3.2% FIMA of burnup. In the post irradiation examination it was observed that among three kinds of TRISO particles exposed to irradiation corresponding to the normal operating condition of the VHTR ones possessing poor characteristics of the coating layers did not show a good stability. The particles irradiated under abnormally high temperature condition (> 1800 0 C) revealed 6.7% of max. EOL failure fraction (95% confidence limit). Most of these particles were failed by the ameoba effect. Furthermore, among four kinds of the TRISO particles exposed to irradiation corresponding to the transient condition of the VHTR (--1500 0 C) the two showed a good stability, while the particles possessing highly anisotropic OLTI-PyC or poorly characteristic coating layers were not so good. (author)

  17. Understanding Violent Behavior in Children and Adolescents

    Science.gov (United States)

    ... for Families - Vietnamese Violent Behavior in Children and Adolescents No. 55; December 2015 There is a great ... the incidence of violent behavior among children and adolescents. This complex and troubling issue needs to be ...

  18. Understanding and Managing Self-Injurious Behavior.

    Science.gov (United States)

    Zirpoli, Thomas J.; Lloyd, John Wills

    1987-01-01

    The literature review looks at self-injurious behaviors in handicapped students in terms of characteristics, prevalence, etiology (biological, psychological, and as learned behavior), and management including extinction, positive punishment, negative punishment, and reinforcement of other behaviors. Problems in areas of management, administration,…

  19. A numerical study of fluidization behavior of Geldart A particles using a discrete particle model

    NARCIS (Netherlands)

    Ye, M.; van der Hoef, Martin Anton; Kuipers, J.A.M.

    2004-01-01

    This paper reports on a numerical study of fluidization behavior of Geldart A particles by use of a 2D soft-sphere discrete particle model (DPM). Some typical features, including the homogeneous expansion, gross particle circulation in the absence of bubbles, and fast bubbles, can be clearly

  20. Irradiation behaviors of coated fuel particles, (3)

    International Nuclear Information System (INIS)

    Fukuda, Kousaku; Kashimura, Satoru; Iwamoto, Kazumi; Ikawa, Katsuichi

    1980-07-01

    This report is concerning to the irradiation experiments of the coated fuel particles, which were performed by 72F-6A and 72F-7A capsules in JMTR. The coated particles referred to the preliminary design of VHTR were prepared for the experiments in 1972 and 1973. 72F-6A capsule was irradiated at G-10 hole of JMTR fuel zone for 2 reactor cycles, and 72F-7A capsule had been planned to be irradiated at the same irradiation hole before 72F-6A. However, due to slight leak of the gaseous fission products into the vacuum system controlling irradiation temperature, irradiation of 72F-7A capsule was ceased after 85 hrs since the beginning. In the post irradiation examination, inspection to surface appearance, ceramography, X-ray microradiography and acid leaching for the irradiated particle samples were made, and crushing strength of the two particle samples was measured. (author)

  1. Simulating human behavior for understanding and managing environmental resource use

    NARCIS (Netherlands)

    Jager, Wander; Mosler, Hans Joachim

    2007-01-01

    Computer simulation allows for the experimental study of dynamic interactions between human behavior and complex environmental systems. Behavioral determinants and processes as identified in social-scientific theory may be formalized in simulated agents to obtain a better understanding of

  2. Tracking Nemo: Help Scientists Understand Zebrafish Behavior.

    Science.gov (United States)

    Tolbert, Tyrone J; Nakayama, Shinnosuke; Porfiri, Maurizio

    2018-02-22

    The advent of automated tracking software has significantly reduced the time required to record movement trajectories, thereby facilitating behavioral studies of zebrafish. However, results are substantially influenced by tracking errors, such as loss and misidentification of individuals. In this study, we present the development of an online citizen science platform, Tracking Nemo, to improve data accuracy on swimming trajectories of zebrafish groups. As an online extension of software for tracking the position of zebrafish from video recordings, Tracking Nemo offers volunteers the opportunity to contribute to science by manually correcting tracked trajectory data from their personal computers. Researchers can upload their videos that require human intervention for correcting and validating the data. Citizen scientists can monitor their contributions through a leaderboard system, which is designed to strengthen participant retention and contribution by tapping into intrinsic and extrinsic motivations. Tracking Nemo is expected to help scientists improve data accuracy through the involvement of citizen scientists, who, in turn, engage in an authentic research activity and learn more about the behavior of zebrafish.

  3. Rheology behavior and optimal damping effect of granular particles in a non-obstructive particle damper

    Science.gov (United States)

    Zhang, Kai; Chen, Tianning; Wang, Xiaopeng; Fang, Jianglong

    2016-03-01

    To explore the optimal damping mechanism of non-obstructive particle dampers (NOPDs), research on the relationship between the damping performance of NOPDs and the motion mode of damping particles in NOPDs was carried out based on the rheological properties of vibrated granular particles. Firstly, the damping performance of NOPDs under different excitation intensity and gap clearance was investigated via cantilever system experiments, and an approximate evaluation of the effective mass and effective damping of NOPDs was performed by fitting the experimental data to an equivalent single-degree-of-freedom (SDOF) system with no damping particles. Then the phase diagrams which could show the motion mode of damping particles under different excitation intensity and gap clearance were obtained via a series of vibration table tests. Moreover, the dissipation characteristic of damping particles was explored by the discrete element method (DEM). The study results indicate that when NOPDs play the optimal damping effect the granular Leidenfrost effect whereby the entire particle bed in NOPDs is levitated above the vibrating base by a layer of highly energetic particles is observed. Finally, the damping characteristics of NOPDs was explained by collisions and frictions between particle-particle and particle-wall based on the rheology behavior of damping particles and a new dissipation mechanism was first proposed for the optimal damping performance of NOPDs.

  4. Understanding slope behavior through microseismic monitoring

    Science.gov (United States)

    Arosio, Diego; Boccolari, Mauro; Longoni, Laura; Papini, Monica; Zanzi, Luigi

    2017-04-01

    It is well known that microseismic activity originates as an elastic stress wave at locations where the material is mechanically unstable. Monitoring techniques focusing on this phenomenon have been studied for over seventy years and are now employed in a wide range of applications. As far as the study of unstable slope is concerned, microseismic monitoring can provide real-time information about fracture formation, propagation and coalescence and may be an appropriate solution to reduce the risk for human settlements when structural mitigation interventions (e.g., rock fall nets and ditches) cannot cope with large rock volumes and high kinetic energies. In this work we present the datasets collected in a 4-year period with a microseismic monitoring network deployed on an unstable rock face in Northern Italy. We mainly focus on the classification and the interpretation of collected signals with the final aim of identifying microseismic events related to the kinematic and dynamic behavior of the slope. We have analyzed signal parameters both in time and frequency domains, spectrograms, polarization of 3-component recordings supported by principal component analysis. Clustering methodologies have been tested in order to develop an automatic classification routine capable to isolate a cluster with most of the events related to slope behavior and to discard all disturbances. The network features both geophones and meteorological sensors so that we could also explore the correlation between microseismic events and meteorological datasets, although no significant relationships emerged. On the contrary, it was found that the majority of the events collected by the network are short-time high-frequency signals generated by electromagnetic activity caused by near and far thunderstorms. Finally, we attempted a preliminary localization of the most promising events according to an oversimplified homogeneous velocity model to get a rough indication about the regions of the

  5. Understanding Editing Behaviors in Multilingual Wikipedia.

    Science.gov (United States)

    Kim, Suin; Park, Sungjoon; Hale, Scott A; Kim, Sooyoung; Byun, Jeongmin; Oh, Alice H

    2016-01-01

    Multilingualism is common offline, but we have a more limited understanding of the ways multilingualism is displayed online and the roles that multilinguals play in the spread of content between speakers of different languages. We take a computational approach to studying multilingualism using one of the largest user-generated content platforms, Wikipedia. We study multilingualism by collecting and analyzing a large dataset of the content written by multilingual editors of the English, German, and Spanish editions of Wikipedia. This dataset contains over two million paragraphs edited by over 15,000 multilingual users from July 8 to August 9, 2013. We analyze these multilingual editors in terms of their engagement, interests, and language proficiency in their primary and non-primary (secondary) languages and find that the English edition of Wikipedia displays different dynamics from the Spanish and German editions. Users primarily editing the Spanish and German editions make more complex edits than users who edit these editions as a second language. In contrast, users editing the English edition as a second language make edits that are just as complex as the edits by users who primarily edit the English edition. In this way, English serves a special role bringing together content written by multilinguals from many language editions. Nonetheless, language remains a formidable hurdle to the spread of content: we find evidence for a complexity barrier whereby editors are less likely to edit complex content in a second language. In addition, we find that multilinguals are less engaged and show lower levels of language proficiency in their second languages. We also examine the topical interests of multilingual editors and find that there is no significant difference between primary and non-primary editors in each language.

  6. Understanding Editing Behaviors in Multilingual Wikipedia.

    Directory of Open Access Journals (Sweden)

    Suin Kim

    Full Text Available Multilingualism is common offline, but we have a more limited understanding of the ways multilingualism is displayed online and the roles that multilinguals play in the spread of content between speakers of different languages. We take a computational approach to studying multilingualism using one of the largest user-generated content platforms, Wikipedia. We study multilingualism by collecting and analyzing a large dataset of the content written by multilingual editors of the English, German, and Spanish editions of Wikipedia. This dataset contains over two million paragraphs edited by over 15,000 multilingual users from July 8 to August 9, 2013. We analyze these multilingual editors in terms of their engagement, interests, and language proficiency in their primary and non-primary (secondary languages and find that the English edition of Wikipedia displays different dynamics from the Spanish and German editions. Users primarily editing the Spanish and German editions make more complex edits than users who edit these editions as a second language. In contrast, users editing the English edition as a second language make edits that are just as complex as the edits by users who primarily edit the English edition. In this way, English serves a special role bringing together content written by multilinguals from many language editions. Nonetheless, language remains a formidable hurdle to the spread of content: we find evidence for a complexity barrier whereby editors are less likely to edit complex content in a second language. In addition, we find that multilinguals are less engaged and show lower levels of language proficiency in their second languages. We also examine the topical interests of multilingual editors and find that there is no significant difference between primary and non-primary editors in each language.

  7. Mean particle diameters : From statistical definition to physical understanding

    NARCIS (Netherlands)

    Alderliesten, M.

    2008-01-01

    Mean particle diameters are important for the science of particulate systems. This thesis deals with a definition system for these mean diameters, called Moment-Ratio (M-R) definition system, and provides a general statistical and physical basis. Also, the current DIN/ISO definition system is

  8. Behavior of small ferromagnetic particles in traveling magnetic field

    Science.gov (United States)

    Deych, V. G.; Terekhov, V. P.

    1985-03-01

    Forces and moments acting on a magnetizable body in a traveling magnetic field are calculated for a body with dimensions much smaller than the wavelength of the magnetic field. It is assumed that a particle of given linear dimension does not have a constant magnetic moment. The material of a particle is characterized by its magnetic permeability and electrical conductivity. The hypothesis that rotation plays a major role in the behavior of small particles is confirmed and the fact that a small particle rolls on a plane, without sliding, when the surface is perfectly rough, in the opposite direction from which the magnetic field travels is explained. Calculations are based on the magnetohydrodynamic equations for a quasi steady magnetic field, and the induced Foucault eddy currents are considered. The results are applicable to transport of ferrofluids and to such metallurgical devices as separators.

  9. Charged particle behavior in localized ultralow frequency waves: Theory and observations

    Science.gov (United States)

    Li, Li; Zhou, Xu-Zhi; Zong, Qiu-Gang; Rankin, Robert; Zou, Hong; Liu, Ying; Chen, Xing-Ran; Hao, Yi-Xin

    2017-06-01

    The formation and variability of the Van Allen radiation belts are highly influenced by charged particles accelerated via drift-resonant interactions with ultralow frequency (ULF) waves. In the prevailing theory of drift resonance, the ULF wave amplitude is assumed independent of magnetic longitude. This assumption is not generally valid in Earth's magnetosphere, as supported by numerous observations that point to the localized nature of ULF waves. Here we introduce a longitude dependence of the ULF wave amplitude, achieved via a von Mises function, into the theoretical framework of ULF wave-particle drift resonance. To validate the revised theory, the predicted particle signatures are compared with observational data through a best fit procedure. It is demonstrated that incorporation of nonlocal effects in drift-resonance theory provides an improved understanding of charged particle behavior in the inner magnetosphere through the intermediary of ULF waves.

  10. Behavior of charged particles in lower ionosphere with acoustical effects

    International Nuclear Information System (INIS)

    Devyaterikov, I.A.; Ivanov, Y.A.; Koslov, S.I.; Kudryavtsev, V.P.

    1984-10-01

    The behavior of charged particles (electrons and positive and negative ions) in the D-region during the passage of weak shock and acoustic waves was studied. It is shown that under such conditions the photochemical equilibrium can be disrupted in the lower part of the D-region, which results in a condition under which the electron density does not follow the variations of neutral gas density

  11. Understanding How Domestic Violence Affects Behavior in High School Students

    Science.gov (United States)

    Frank, Malika

    2011-01-01

    This paper will provide the reader with an understanding of how domestic violence affects the behavior of high school students. The presentation is designed to provide the reader with a working definition of domestic violence, the rate of occurrence and its effects on high school students. Additionally the paper will summarize the negative effects…

  12. Children's Understanding of Display Rules for Expressive Behavior.

    Science.gov (United States)

    Saarni, Carolyn

    1979-01-01

    Examined how children come to understand that internally experienced affect need not be behaviorally expressed and that the emotion that is expressed is not necessarily what is being felt internally. Sixty elementary school students were interviewed about four interpersonal conflict situations presented in comic strip style but using photographs…

  13. Understanding child sexual behavior problems: a developmental psychopathology framework.

    Science.gov (United States)

    Elkovitch, Natasha; Latzman, Robert D; Hansen, David J; Flood, Mary Fran

    2009-11-01

    Children exhibiting sexual behavior have increasingly gained the attention of child welfare and mental health systems, as well as the scientific community. While a heterogeneous group, children with sexual behavior problems consistently demonstrate a number of problems related to adjustment and overall development. In order to appropriately intervene with these children, a comprehensive understanding of etiology is imperative. The overarching goal of the present paper is to review the extant research on mechanisms associated with the development of problematic sexual behavior in childhood within a developmental psychopathology framework. What is known about normative and nonnormative sexual behavior in childhood is reviewed, highlighting definitional challenges and age-related developmental differences. Further, the relationship between child sexual abuse and child sexual behavior problems is discussed, drawing attention to factors impacting this relationship. Risk factors for child sexual behavior problems, beyond that of sexual abuse, are also reviewed utilizing a transactional-ecological framework. Finally, we conclude with a discussion of implications of a developmental psychopathology perspective on problematic child sexual behaviors to inform future research and intervention efforts. Such implications include the need for attention to normative childhood sexual behavior, developmental sensitivity, and examinations of ecological domain in concert.

  14. Designing Graphs that Promote Both Risk Understanding and Behavior Change.

    Science.gov (United States)

    Okan, Yasmina; Stone, Eric R; Bruine de Bruin, Wändi

    2017-10-03

    Graphs show promise for improving communications about different types of risks, including health risks, financial risks, and climate risks. However, graph designs that are effective at meeting one important risk communication goal (promoting risk-avoidant behaviors) can at the same time compromise another key goal (improving risk understanding). We developed and tested simple bar graphs aimed at accomplishing these two goals simultaneously. We manipulated two design features in graphs, namely, whether graphs depicted the number of people affected by a risk and those at risk of harm ("foreground+background") versus only those affected ("foreground-only"), and the presence versus absence of simple numerical labels above bars. Foreground-only displays were associated with larger risk perceptions and risk-avoidant behavior (i.e., willingness to take a drug for heart attack prevention) than foreground+background displays, regardless of the presence of labels. Foreground-only graphs also hindered risk understanding when labels were not present. However, the presence of labels significantly improved understanding, eliminating the detrimental effect of foreground-only displays. Labels also led to more positive user evaluations of the graphs, but did not affect risk-avoidant behavior. Using process modeling we identified mediators (risk perceptions, understanding, user evaluations) that explained the effect of display type on risk-avoidant behavior. Our findings contribute new evidence to the graph design literature: unlike what was previously feared, we demonstrate that it is possible to design foreground-only graphs that promote intentions for behavior change without a detrimental effect on risk understanding. Implications for the design of graphical risk communications and decision support are discussed. © 2017 Society for Risk Analysis.

  15. Understanding particle size and distance driven competition of interparticle interactions and effective single-particle anisotropy

    Czech Academy of Sciences Publication Activity Database

    Pacáková, Barbara; Mantlíková, Alice; Nižňanský, D.; Kubíčková, Simona; Vejpravová, Jana

    2016-01-01

    Roč. 28, č. 20 (2016), 1-11, č. článku 206004. ISSN 0953-8984 R&D Projects: GA ČR(CZ) GA15-01953S Institutional support: RVO:68378271 Keywords : magnetic nanoparticles * single-particle anisotropy * dipolar energy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.649, year: 2016

  16. Effect of particle shape on mechanical behaviors of rocks: a numerical study using clumped particle model.

    Science.gov (United States)

    Rong, Guan; Liu, Guang; Hou, Di; Zhou, Chuang-Bing

    2013-01-01

    Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.

  17. Understanding particle size and distance driven competition of interparticle interactions and effective single-particle anisotropy.

    Science.gov (United States)

    Pacakova, B; Mantlikova, A; Niznansky, D; Kubickova, S; Vejpravova, J

    2016-05-25

    Magnetic response of single-domain nanoparticles (NPs) in concentrated systems is strongly affected by mutual interparticle interactions. However, particle proximity significantly influences single-particle effective anisotropy. To solve which of these two phenomena plays a dominant role in the magnetic response of real NP systems, systematic study on samples with well-defined parameters is required. In our work, we prepared a series of nanocomposites constituted of highly-crystalline and well-isolated CoFe2O4 NPs embedded in an amorphous SiO2 matrix using a single-molecule precursor method. This preparation method enabled us to reach a wide interval of particle size and concentration. We observed that the characteristic parameters of the single-domain state (coercivity, blocking temperature) and dipole-dipole interaction energy ([Formula: see text]) scaled with each other and increased with increasing [Formula: see text], where d XRD was the NP diameter and r was the interparticle distance. Our results are in excellent agreement with Monte-Carlo simulations of the particle growth. Moreover, we demonstrated that the contribution of [Formula: see text] acting as an additional energetic barrier to the superspin reversal or as an average static field did not sufficiently explain how the concentrated NP systems responded to an external magnetic field. Alternations in the blocking temperature and coercivity of our NP systems accounted for reformed relaxations of the NP superspins and modified effective anisotropy energy of the interacting NPs. Therefore, the concept of modified NP effective anisotropy explains the magnetic response of our concentrated NP systems better than the concept of the energy barrier influenced by interparticle interactions.

  18. Understanding Eating Behaviors through Parental Communication and the Integrative Model of Behavioral Prediction.

    Science.gov (United States)

    Scheinfeld, Emily; Shim, Minsun

    2017-05-01

    Emerging adulthood (EA) is an important yet overlooked period for developing long-term health behaviors. During these years, emerging adults adopt health behaviors that persist throughout life. This study applies the Integrative Model of Behavioral Prediction (IMBP) to examine the role of childhood parental communication in predicting engagement in healthful eating during EA. Participants included 239 college students, ages 18 to 25, from a large university in the southern United States. Participants were recruited and data collection occurred spring 2012. Participants responded to measures to assess perceived parental communication, eating behaviors, attitudes, subjective norms, and behavioral control over healthful eating. SEM and mediation analyses were used to address the hypotheses posited. Data demonstrated that perceived parent-child communication - specifically, its quality and target-specific content - significantly predicted emerging adults' eating behaviors, mediated through subjective norm and perceived behavioral control. This study sets the stage for further exploration and understanding of different ways parental communication influences emerging adults' healthy behavior enactment.

  19. Video-CRM: understanding customer behaviors in stores

    Science.gov (United States)

    Haritaoglu, Ismail; Flickner, Myron; Beymer, David

    2013-03-01

    This paper describes two real-time computer vision systems created 10 years ago that detect and track people in stores to obtain insights of customer behavior while shopping. The first system uses a single color camera to identify shopping groups in the checkout line. Shopping groups are identified by analyzing the inter-body distances coupled with the cashier's activities to detect checkout transactions start and end times. The second system uses multiple overhead narrow-baseline stereo cameras to detect and track people, their body posture and parts to understand customer interactions with products such as "customer picking a product from a shelf". In pilot studies both systems demonstrated real-time performance and sufficient accuracy to enable more detailed understanding of customer behavior and extract actionable real-time retail analytics.

  20. Multi-data Mining for Understanding Leadership Behavior

    Directory of Open Access Journals (Sweden)

    Naohiro Matsumura

    2007-03-01

    Full Text Available We propose an approach for understanding leadership behavior in dot-jp, a non-profit organization, by analyzing heterogeneous multi-data composed of questionnaires and mailing list archives. Attitudes toward leaders were obtained from the questionnaires, and human networks were extracted from the mailing list archives. By integrating the results, we discovered that leaders must receive messages from other people as well as send messages to construct reliable relationships.

  1. Influence of Particle Theory Conceptions on Pre-Service Science Teachers' Understanding of Osmosis and Diffusion

    Science.gov (United States)

    AlHarbi, Nawaf N. S.; Treagust, David F.; Chandrasegaran, A. L.; Won, Mihye

    2015-01-01

    This study investigated the understanding of diffusion, osmosis and particle theory of matter concepts among 192 pre-service science teachers in Saudi Arabia using a 17-item two-tier multiple-choice diagnostic test. The data analysis showed that the pre-service teachers' understanding of osmosis and diffusion concepts was mildly correlated with…

  2. A Study of Wire Breakup and In-Flight Particle Behavior During Wire Flame Spraying of Aluminum

    Science.gov (United States)

    Lunn, G. D.; Riley, M. A.; McCartney, D. G.

    2017-12-01

    Although wire flame spraying has been used for many years, there has been relatively little attention given to understanding the process dynamics. In this work, imaging of the molten wire tip, particle imaging using the Oseir SprayWatch system and particle capture (wipe tests) have all been employed to quantify plume behavior. Aluminum wire feedstock is melted and then breaks up close to the exit of the spray nozzle in a non-axisymmetric manor. The mean velocity and diameter of the particles detected by the SprayWatch system change little with standoff distance with values of approximately 280 m/s and 70 µm, respectively, for the spray parameters employed. The particle diagnostic system could not detect particles ⪅45 µm in diameter, and it is estimated that these account for no more than 53% of the sprayed material. Overall, wire flame spraying generates a surprisingly stable particle stream.

  3. Systematic behavior research for understanding consumer decision making.

    Science.gov (United States)

    Lin, Chin-Feng

    2009-05-01

    This study incorporates means-end chain (MEC) theory and dynamic programming for understanding the implications of consumer decision making. The conceptual framework of this study can help programmers design information systems for analyzing consumption behaviors. Such analyses will provide marketers with meaningful information for formulating marketing strategies. The main contributions of this article are as follows: (1) to enable researchers to obtain information for consumer cognitive hierarchies utilizing an information system, (2) to enhance the functions of traditional MEC methodology and provide an integrated method for analyzing consumption information, and (3) to construct an information system for analyzing consumer decision-making processes.

  4. Prediction of granule packing and flow behavior based on particle size and shape analysis.

    Science.gov (United States)

    Sandler, Niklas; Wilson, David

    2010-02-01

    Packing behavior and flowability of particulate material have long been acknowledged as important parameters for the processing of pharmaceutical materials. When properly understood, these properties can provide insight into weight uniformity, tableting performance and process design. The aim of this study was to measure particle size and shape distributions of different granular intermediates with a dynamic particle size image analyzer, and then use these distributions to predict packing efficiency and different metrics of flowability by employing partial least squares (PLS) modeling. From measurements of size and shape, a model was constructed that allowed for the prediction of flowability indices, bulk and tap densities with a high degree of accuracy for the granular materials used. In this study the use of size and shape distributions in the construction of a model providing both accurate flowability indices and bulk and tap density estimates has been demonstrated for example granular materials in which cohesive forces did not dominate powder behavior. It is believed that the continued application of the outlined experimental design would eventually lead to the fundamental understanding of how size and shape characteristics of materials influence particle behavior including downstream processibility. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

  5. Semiclassical asymptotic behavior and the rearrangement mechanisms for Coulomb particles

    International Nuclear Information System (INIS)

    Bogdanov, A.V.; Gevorkyan, A.S.; Dubrovskii, G.V.

    1986-01-01

    The semiclassical asymptotic behavior of the eikonal amplitude of the resonance rearrangement in a system of three Coulomb particles is studied. It is shown that the general formula for the amplitude correctly describes two classical mechanisms (pickup and knockout) and one nonclassical mechanism (stripping). The classical mechanisms predominate at high energies, while the stripping mechanism predominates at lower energies. In the region of medium energies the dominant mechanism is the pickup (or Thomas) mechanism, which is realized by nonclassical means. For such transitions the classical cross section diverges, and the amplitude must be computed on a complex trajectory. The physical reasons for introducing the approximate complex trajectories are discussed. The contributions of all the mechanisms to the rearrangement cross section are found in their analytic forms

  6. Hygroscopic particle behavior studied by interdigitated array microelectrode impedance sensors.

    Science.gov (United States)

    Schindelholz, Eric; Tsui, Lok-kun; Kelly, Robert G

    2014-01-09

    The hygroscopic behavior of soluble salts bears importance in many research fields including atmospheric sciences, corrosion, porous building materials, and pharmaceuticals. Several methods have been used to study deliquescence (solid to liquid) and efflorescence (liquid to solid) phase transitions of these salts. In this study, we measured the deliquescence and efflorescence RH values of single salt microparticles deposited on an interdigitated microelectrode sensor via electrical impedance. The salts examined were NaCl, LiCl, NaBr, KCl, and MgCl2. Measured values were in agreement with in situ optical microscopic observations and, with the exception of MgCl2, literature values. In the case of MgCl2, deliquescence occurred at 33% RH and 12-15% RH, with the latter range being previously unreported. The depressed deliquescence RH was hypothesized to be a result of the formation of a metastable MgCl2 hydrate. Incomplete efflorescence of MgCl2 was also observed after exposure to method as an alternative or complementary method for study of bulk-phase transitions of substrate-deposited particles across a broad RH range. These findings also demonstrate the utility of this method for detection of fluid trapping which cannot be directly ascertained by gravimetric and line-of-sight techniques commonly used in the study of hygroscopic particles.

  7. Neurobiological considerations in understanding behavioral treatments for pathological gambling.

    Science.gov (United States)

    Potenza, Marc N; Balodis, Iris M; Franco, Christine A; Bullock, Scott; Xu, Jiansong; Chung, Tammy; Grant, Jon E

    2013-06-01

    Pathological gambling (PG), a disorder currently categorized as an impulse-control disorder but being considered as a nonsubstance addiction in Diagnostic and Statistical Manual of Mental Disorders (5th ed.) discussions, represents a significant public health concern. Over the past decade, considerable advances have been made with respect to understanding the biological underpinnings of PG. Research has also demonstrated the efficacies of multiple treatments, particularly behavioral therapies, for treating PG. Despite these advances, relatively little is known regarding how biological measures, particularly those assessing brain function, relate to treatments for PG. In this article, we present a conceptual review focusing on the neurobiology of behavioral therapies for PG. To illustrate issues related to study design, we present proof-of-concept preliminary data that link Stroop-related brain activations prior to treatment onset to treatment outcome in individuals with PG receiving a cognitive-behavioral treatment incorporating aspects of imaginal desensitization and motivational interviewing. We conclude with recommendations about current and future directions regarding how to incorporate and translate biological findings into improved therapies for individuals with nonsubstance and substance addictions. 2013 APA, all rights reserved

  8. Neurobiological considerations in understanding behavioral treatments for pathological gambling

    Science.gov (United States)

    Potenza, Marc N.; Balodis, Iris M.; Franco, Christine A.; Bullock, Scott; Xu, Jiansong; Chung, Tammy; Grant, Jon E.

    2013-01-01

    Pathological gambling (PG), a disorder currently categorized as an impulse-control disorder but being considered as a non-substance addiction in DSM-5 discussions, represents a significant public health concern. Over the past decade, considerable advances have been made with respect to understanding the biological underpinnings of PG. Research has also demonstrated the efficacies of multiple treatments, particularly behavioral therapies, for treating PG. Despite these advances, relatively little is known regarding how biological measures, particularly those assessing brain function, relate to treatments for PG. In this article, we present a conceptual review focusing on the neurobiology of behavioral therapies for PG. To illustrate issues related to study design, we present proof-of-concept preliminary data that link Stroop-related brain activations prior to treatment onset to treatment outcome in individuals with PG receiving a cognitive behavioral treatment incorporating aspects of imaginal desensitization and motivational interviewing. We conclude with recommendations about current and future directions regarding how to incorporate and translate biological findings into improved therapies for individuals with non-substance and substance addictions. PMID:23586456

  9. IMS (International Magnetospheric Study) contributions to the understanding of auroral precipitation, transport, and particle sources

    Energy Technology Data Exchange (ETDEWEB)

    Fennell, J.F.

    1985-03-01

    The progress in our understanding of plasma processes throughout the magnetosphere has increased dramatically during the International Magnetospheric Study (IMS) period. In this report the auroral ionosphere as a source of particles for the magnetosphere and the auroral particle acceleration and precipitation are emphasized. Some of the processes involved in the transport of particles from the ionosphere out into the magnetosphere are treated as well as the precipitation of magnetospheric particles into the auroral and subauroral ionosphere. Some of the effects auroral ionospheric ions have on the magnetospheric plasma composition are described. A brief overview of pre-IMS results is also given to set the stage for a description of IMS contributions in these areas.

  10. Dynamic localization and shear-induced hopping of particles: A way to understand the rheology of dense colloidal dispersions

    International Nuclear Information System (INIS)

    Jiang, Tianying; Zukoski, Charles F.

    2014-01-01

    For decades, attempts have been made to understand the formation of colloidal glasses and gels by linking suspension mechanics to particle properties where details of size, shape, and spatial dependencies of pair potentials present a bewildering array of variables that can be manipulated to achieve observed properties. Despite the range of variables that control suspension properties, one consistent observation is the remarkably similarity of flow properties observed as particle properties are varied. Understanding the underlying origins of the commonality in those behaviors (e.g., shear-thinning with increasing stress, diverging zero shear rate viscosity with increasing volume fraction, development of a dynamic yield stress plateau with increases in volume faction or strength of attraction, development of two characteristic relaxation times probed in linear viscoelasticity, the creation of a rubbery plateau modulus at high strain frequencies, and shear-thickening) remains a challenge. Recently, naïve mode coupling and dynamic localization theories have been developed to capture collective behavior giving rise to formation of colloidal glasses and gels. This approach characterizes suspension mechanics of strongly interacting particles in terms of sluggish long-range particle diffusion modulated by varying particle interactions and volume fraction. These theories capture the scaling of the modulus with the volume fraction and strength of interparticle attraction, the frequency dependence of the moduli at the onset of the gel/glass transition, together with the divergence of the zero shear rate viscosity and cessation of diffusivity for hard sphere systems as close packing is approached. In this study, we explore the generality of the predictions of dynamic localization theory for systems of particles composed of bimodal particle size distributions experiencing weak interactions. We find that the mechanical properties of these suspensions are well captured within

  11. Understanding the link between GMP and dough: From glutenin particles in flour towards developed dough

    NARCIS (Netherlands)

    Don, C.; Lichtendonk, W.J.; Plijter, J.J.; Hamer, R.J.

    2003-01-01

    Clear correlations exist for glutenin macropolymer (GMP) quantity and rheological properties vs. wheat quality and dough rheological properties, but real insight in understanding these links is still missing. The observation that GMP consists of glutenin particles opens up new possibilities to

  12. Learning about a Level Physics Students' Understandings of Particle Physics Using Concept Mapping

    Science.gov (United States)

    Gourlay, H.

    2017-01-01

    This paper describes a small-scale piece of research using concept mapping to elicit A level students' understandings of particle physics. Fifty-nine year 12 (16- and 17 year-old) students from two London schools participated. The exercise took place during school physics lessons. Students were instructed how to make a concept map and were…

  13. Understanding the Implications of Neural Population Activity on Behavior

    Science.gov (United States)

    Briguglio, John

    Learning how neural activity in the brain leads to the behavior we exhibit is one of the fundamental questions in Neuroscience. In this dissertation, several lines of work are presented to that use principles of neural coding to understand behavior. In one line of work, we formulate the efficient coding hypothesis in a non-traditional manner in order to test human perceptual sensitivity to complex visual textures. We find a striking agreement between how variable a particular texture signal is and how sensitive humans are to its presence. This reveals that the efficient coding hypothesis is still a guiding principle for neural organization beyond the sensory periphery, and that the nature of cortical constraints differs from the peripheral counterpart. In another line of work, we relate frequency discrimination acuity to neural responses from auditory cortex in mice. It has been previously observed that optogenetic manipulation of auditory cortex, in addition to changing neural responses, evokes changes in behavioral frequency discrimination. We are able to account for changes in frequency discrimination acuity on an individual basis by examining the Fisher information from the neural population with and without optogenetic manipulation. In the third line of work, we address the question of what a neural population should encode given that its inputs are responses from another group of neurons. Drawing inspiration from techniques in machine learning, we train Deep Belief Networks on fake retinal data and show the emergence of Garbor-like filters, reminiscent of responses in primary visual cortex. In the last line of work, we model the state of a cortical excitatory-inhibitory network during complex adaptive stimuli. Using a rate model with Wilson-Cowan dynamics, we demonstrate that simple non-linearities in the signal transferred from inhibitory to excitatory neurons can account for real neural recordings taken from auditory cortex. This work establishes and tests

  14. Radiography as a tool in understanding soil insect behavior in turfgrass

    International Nuclear Information System (INIS)

    Villani, M.G.; Wright, R.J.

    1987-01-01

    In an effort to gain a more realistic picture of the events that occur within the soil matrix an x-ray technique has been developed that has been used to study seed insects, parasitized cocoons, and wood boring insects in trees to study soil insect movement and behavior. This technique makes it possible to study the movement of the target insects within simulated or natural soil blocks over time. This method also shows physical properties of the soil matrix: particle size, extent of compaction, differences in soil moisture, horizons, and random soil heterogeneity. Blocks of soil up to 14'' x 17'' x 5'' have been removed from the field and x-rayed in my laboratory using this technique. These radiographs are of sufficient quality to determine the movement of white grubs in situ. Such blocks retain their field characteristics and therefore allow for the careful monitoring and manipulation of the system over relatively long (several months) periods of time. Radiographic data are presented which document the behavior of several white grub species in response to dynamic soil ecosystem processes such as moisture and temperature flux. Additional data on the effects of specific soil insecticides on the behavior of white grubs in the soil and the movement of these insecticides through the soil profile are also presented. The importance of understanding the dynamic interaction of soil insect and soil insecticide provided through x-ray technology, both in understanding white grub behavior in the field and maximizing management efforts is discussed

  15. A reduced complexity discrete particle model for understanding the sediment dynamics of steep upland river confluences

    Science.gov (United States)

    Tancock, M. J.; Lane, S. N.; Hardy, R. J.

    2012-12-01

    There has been a significant amount of research conducted in order to understand the flow fields at natural river confluences. Much of this has been made possible due to advances in the use of Computational Fluid Dynamics (CFD). However, much of this research has been conducted on river confluences with negligible water surface slopes and any understanding of the sediment dynamics is largely implied from the flow fields. Therefore, a key challenge is to understand the flow and sediment dynamics of steep river confluences with dynamic boundaries. Two numerical modelling developments are presented which together are capable of increasing our understanding of the sediment dynamics of steep river confluences. The first is the application of a Height-of-Liquid (HOL) model within a CFD framework to explicitly solve the water surface elevation. This is a time-dependent, multiphase treatment of the fluid dynamics which solves for the change in volume of water and air in each vertical column of the mesh. The second is the development of a reduced complexity discrete particle transport model which uses the change in momentum on a spherical particle to predict the transport paths through the flow field determined from CFD simulations. The performance of the two models is tested using field data from a series of highly dynamic, steep gravel-bed confluences on a braidplain of the Borgne d'Arolla, Switzerland. The HOL model is validated against the water surface elevation and flow velocity data and is demonstrated to provide a reliable representation of the flow field in fast-flowing, supercritical flows. In order to validate the discrete particle model, individual particles were tracked using electronic tacheometry. The model is demonstrated to accurately represent the particle tracks obtained in the field and provides a new methodology to understand the dynamic morphology of braid plains.

  16. Understanding Jordanian Psychiatric Nurses’ Smoking Behaviors: A Grounded Theory Study

    Directory of Open Access Journals (Sweden)

    Khaldoun M. Aldiabat

    2013-01-01

    Full Text Available Purpose. Smoking is prevalent in psychiatric facilities among staff and patients. However, there have been few studies of how contextual factors in specific cultures influence rates of smoking and the health promotion role of psychiatric nurses. This paper reports the findings of a classical grounded theory study conducted to understand how contextual factors in the workplace influences the smoking behaviors of Jordanian psychiatric nurses (JPNs. Method. Semi-structured individual interviews were conducted with a sample of eight male JPNs smokers at a psychiatric facility in Amman, Jordan. Findings. Constant comparative analysis identified becoming a heavy smoker as a psychosocial process characterized by four sub-categories: normalization of smoking; living in ambiguity; experiencing workplace conflict; and, facing up to workplace stressors. Conclusion. Specific contextual workplace factors require targeted smoking cessation interventions if JPNs are to receive the help they need to reduce health risks associated with heavy smoking.

  17. Understanding the control of ingestive behavior in primates.

    Science.gov (United States)

    Wilson, Mark E; Moore, Carla J; Ethun, Kelly F; Johnson, Zachary P

    2014-06-01

    This article is part of a Special Issue "Energy Balance". Ingestive behavior in free-ranging populations of nonhuman primates is influenced by resource availability and social group organization and provides valuable insight on the evolution of ecologically adaptive behaviors and physiological systems. As captive populations were established, questions regarding proximate mechanisms that regulate food intake in these animals could be more easily addressed. The availability of these captive populations has led to the use of selected species to understand appetite control or metabolic physiology in humans. Recognizing the difficulty of quantitating food intake in free-ranging groups, the use of captive, singly-housed animals provided a distinct advantage though, at the same time, produced a different social ecology from the animals' natural habitat. However, the recent application of novel technologies to quantitate caloric intake and energy expenditure in free-feeding, socially housed monkeys permits prospective studies that can accurately define how food intake changes in response to any number of interventions in the context of a social environment. This review provides an overview of studies examining food intake using captive nonhuman primates organized into three areas: a) neurochemical regulation of food intake in nonhuman primates; b) whether exposure to specific diets during key developmental periods programs differences in diet preferences or changes the expression of feeding related neuropeptides; and c) how psychosocial factors influence appetite regulation. Because feeding patterns are driven by more than just satiety and orexigenic signals, appreciating how the social context influences pattern of feeding in nonhuman primates may be quite informative for understanding the biological complexity of feeding in humans. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Understanding and Predicting Human Behavior for Social Communities

    Science.gov (United States)

    Simoes, Jose; Magedanz, Thomas

    Over the last years, with the rapid advance in technology, it is becoming increasingly feasible for people to take advantage of the devices and services in the surrounding environment to remain "connected" and continuously enjoy the activity they are engaged in, be it sports, entertainment, or work. Such a ubiquitous computing environment will allow everyone permanent access to the Internet anytime, anywhere and anyhow [1]. Nevertheless, despite the evolution of services, social aspects remain in the roots of every human behavior and activities. Great examples of such phenomena are online social networks, which engage users in a way never seen before in the online world. At the same time, being aware and communicating context is a key part of human interaction and is a particularly powerful concept when applied to a community of users where services can be made more personalized and useful. Altogether, harvesting context to reason and learn about user behavior will further enhance the future multimedia vision where services can be composed and customized according to user context. Moreover, it will help us to understand users in a better way.

  19. Understanding recurrent crime as system-immanent collective behavior.

    Directory of Open Access Journals (Sweden)

    Matjaž Perc

    Full Text Available Containing the spreading of crime is a major challenge for society. Yet, since thousands of years, no effective strategy has been found to overcome crime. To the contrary, empirical evidence shows that crime is recurrent, a fact that is not captured well by rational choice theories of crime. According to these, strong enough punishment should prevent crime from happening. To gain a better understanding of the relationship between crime and punishment, we consider that the latter requires prior discovery of illicit behavior and study a spatial version of the inspection game. Simulations reveal the spontaneous emergence of cyclic dominance between "criminals", "inspectors", and "ordinary people" as a consequence of spatial interactions. Such cycles dominate the evolutionary process, in particular when the temptation to commit crime or the cost of inspection are low or moderate. Yet, there are also critical parameter values beyond which cycles cease to exist and the population is dominated either by a stable mixture of criminals and inspectors or one of these two strategies alone. Both continuous and discontinuous phase transitions to different final states are possible, indicating that successful strategies to contain crime can be very much counter-intuitive and complex. Our results demonstrate that spatial interactions are crucial for the evolutionary outcome of the inspection game, and they also reveal why criminal behavior is likely to be recurrent rather than evolving towards an equilibrium with monotonous parameter dependencies.

  20. Experimental and simulation studies on the behavior of signal harmonics in magnetic particle imaging.

    Science.gov (United States)

    Murase, Kenya; Konishi, Takashi; Takeuchi, Yuki; Takata, Hiroshige; Saito, Shigeyoshi

    2013-07-01

    Our purpose in this study was to investigate the behavior of signal harmonics in magnetic particle imaging (MPI) by experimental and simulation studies. In the experimental studies, we made an apparatus for MPI in which both a drive magnetic field (DMF) and a selection magnetic field (SMF) were generated with a Maxwell coil pair. The MPI signals from magnetic nanoparticles (MNPs) were detected with a solenoid coil. The odd- and even-numbered harmonics were calculated by Fourier transformation with or without background subtraction. The particle size of the MNPs was measured by transmission electron microscopy (TEM), dynamic light-scattering, and X-ray diffraction methods. In the simulation studies, the magnetization and particle size distribution of MNPs were assumed to obey the Langevin theory of paramagnetism and a log-normal distribution, respectively. The odd- and even-numbered harmonics were calculated by Fourier transformation under various conditions of DMF and SMF and for three different particle sizes. The behavior of the harmonics largely depended on the size of the MNPs. When we used the particle size obtained from the TEM image, the simulation results were most similar to the experimental results. The similarity between the experimental and simulation results for the even-numbered harmonics was better than that for the odd-numbered harmonics. This was considered to be due to the fact that the odd-numbered harmonics were more sensitive to background subtraction than were the even-numbered harmonics. This study will be useful for a better understanding, optimization, and development of MPI and for designing MNPs appropriate for MPI.

  1. Emergent behaviors in RBCs flows in micro-channels using digital particle image velocimetry.

    Science.gov (United States)

    Cairone, F; Ortiz, D; Cabrales, P J; Intaglietta, M; Bucolo, M

    2018-03-01

    The key points in the design of microfluidic Lab-On-a-Chips for blood tests are the simplicity of the microfluidic chip geometry, the portability of the monitoring system and the ease on-chip integration of the data analysis procedure. The majority of those, recently designed, have been used for blood separation, however their introduction, also, for pathological conditions diagnosis would be important in different biomedical contexts. To overcome this lack is necessary to establish the relation between the RBCs flow and blood viscosity changes in micro-vessels. For that, the development of methods to analyze the dynamics of the RBCs flows in networks of micro-channels becomes essential in the study of RBCs flows in micro-vascular networks. A simplification in the experimental set-up and in the approach for the data collection and analysis could contribute significantly to understand the relation between the blood non-Newtonian properties and the emergent behaviors in collective RBCs flows. In this paper, we have investigated the collective behaviors of RBCs in a micro-channel in unsteady conditions, using a simplified monitoring set-up and implementing a 2D image processing procedure based on the digital particle image velocimetry. Our experimental study consisted in the analysis of RBCs motions freely in the micro-channel and driven by an external pressure. Despite the equipment minimal complexity, the advanced signal processing method implemented has allowed a significant qualitative and quantitative classification of the RBCs behaviors and the dynamical characterization of the particles velocities along both the horizontal and vertical directions. The concurrent causes for the particles displacement as the base solution-particles interaction, particle-particle interaction, and the external force due to pressure gradient were accounted in the results interpretation. The method implemented and the results obtained represent a proof of concept toward the

  2. Simulating Sand Behavior through Terrain Subdivision and Particle Refinement

    Science.gov (United States)

    Clothier, M.

    2013-12-01

    Advances in computer graphics, GPUs, and parallel processing hardware have provided researchers with new methods to visualize scientific data. In fact, these advances have spurred new research opportunities between computer graphics and other disciplines, such as Earth sciences. Through collaboration, Earth and planetary scientists have benefited by using these advances in hardware technology to process large amounts of data for visualization and analysis. At Oregon State University, we are collaborating with the Oregon Space Grant and IGERT Ecosystem Informatics programs to investigate techniques for simulating the behavior of sand. In addition, we have also been collaborating with the Jet Propulsion Laboratory's DARTS Lab to exchange ideas on our research. The DARTS Lab specializes in the simulation of planetary vehicles, such as the Mars rovers. One aspect of their work is testing these vehicles in a virtual "sand box" to test their performance in different environments. Our research builds upon this idea to create a sand simulation framework to allow for more complex and diverse environments. As a basis for our framework, we have focused on planetary environments, such as the harsh, sandy regions on Mars. To evaluate our framework, we have used simulated planetary vehicles, such as a rover, to gain insight into the performance and interaction between the surface sand and the vehicle. Unfortunately, simulating the vast number of individual sand particles and their interaction with each other has been a computationally complex problem in the past. However, through the use of high-performance computing, we have developed a technique to subdivide physically active terrain regions across a large landscape. To achieve this, we only subdivide terrain regions where sand particles are actively participating with another object or force, such as a rover wheel. This is similar to a Level of Detail (LOD) technique, except that the density of subdivisions are determined by

  3. Understanding and exploiting nanoscale surface heterogeneity for particle and cell manipulation

    Science.gov (United States)

    Kalasin, Surachate

    This thesis explores the impact of surface heterogeneities on colloidal interactions and translates concepts to biointerfacial systems, for instance, microfluidic and biomedical devices. The thesis advances a model system, originally put forth by Kozlova: Tunable electrostatic surface heterogeneity is produced by adsorbing small amounts of cationic polyelectrolyte on a silica flat. The resulting positive electrostatic patches possess a density that is tuned from a saturated carpet down to average spacings on the order of a few hundred nanometers. At these length-scales, multiple adhesive elements (from tens to thousands) are present in the area of contact between a particle and a surface, a distinguishing feature of the thesis. Much of the literature addressing surface "heterogeneity" engineers surfaces with micron-scale features, almost always larger than the contact area between a particle and a second surface. With a nanoscale heterogeneity model, this thesis reports and quantitatively explains particle interaction behavior not typical of homogeneous interfaces. This includes (1) an adhesion threshold, a minimum average surface density of cationic patches needed for particle capture, (previously observed by Kozlova); (2) a crossover, from salt-destabilized to salt-stabilized interactions between heterogeneous surfaces with net-negative charge; (3) a shift of the adhesion threshold with shear, reducing adhesion; (4) a crossover from shear-enhanced to shear-hindered particle adhesion; (5) a range of surface compositions and processing parameters that sustain particle rolling; and (6) conditions where particles arrest immediately on contact. Through variations in ionic strength and particle size, the particle-surface contact area is systematically varied relative to the heterogeneity lengthscale. This provides a semi-quantitative explanation for the shifting of the adhesion threshold, in terms of the statistical probability of a particle being able to find a

  4. Bounce behavior of freshly nucleated biogenic secondary organic aerosol particles

    Directory of Open Access Journals (Sweden)

    A. Virtanen

    2011-08-01

    Full Text Available The assessment of the climatic impacts and adverse health effects of atmospheric aerosol particles requires detailed information on particle properties. However, very limited information is available on the morphology and phase state of secondary organic aerosol (SOA particles. The physical state of particles greatly affects particulate-phase chemical reactions, and thus the growth rates of newly formed atmospheric aerosol. Thus verifying the physical phase state of SOA particles gives new and important insight into their formation, subsequent growth, and consequently potential atmospheric impacts. According to our recent study, biogenic SOA particles produced in laboratory chambers from the oxidation of real plant emissions as well as in ambient boreal forest atmospheres can exist in a solid phase in size range >30 nm. In this paper, we extend previously published results to diameters in the range of 17–30 nm. The physical phase of the particles is studied by investigating particle bounce properties utilizing electrical low pressure impactor (ELPI. We also investigate the effect of estimates of particle density on the interpretation of our bounce observations. According to the results presented in this paper, particle bounce clearly decreases with decreasing particle size in sub 30 nm size range. The comparison measurements by ammonium sulphate and investigation of the particle impaction velocities strongly suggest that the decreasing bounce is caused by the differences in composition and phase of large (diameters greater than 30 nm and smaller (diameters between 17 and 30 nm particles.

  5. Understanding the behavior of floodplains as human-water systems

    Science.gov (United States)

    Di Baldassarre, G.; Brandimarte, L.

    2012-12-01

    Floodplains are among the most valuable ecosystems for supporting biodiversity and providing services to the environment. Moreover, they are home of approximately one-sixth of the world population as they offer favorable conditions for economic development. As a result, flood disasters currently affect more than 100 million people a year. Sadly, flood losses and fatalities are expected to increase further in many countries because of population growth as well as changes in land use and climate. Given the relevance of floodplain systems, a number of social scientists have examined how the frequency and severity of flooding often determine whether human development in floodplains is desirable or not. Meanwhile, many earth scientists have investigated the impact of human activities (e.g. land-use changes, urbanization, river training) on the frequency and magnitude of floods. In fact, as human activities change the frequency of flooding, the frequency of flooding affects human developments in floodplain areas. Yet, these dynamic interactions between floods and societies and the associated feedback mechanisms remain largely unexplored and poorly understood. As a result, we typically consider humans as external forcing (or boundary condition) without representing the feedback loops and our prediction of future trajectories are therefore extremely limited. This presentation shows a first attempt to understand the behavior of floodplains as coupled human-water systems. In particular, we analyzed a number of long time series of hydrological and population data in the Po River Basin (Italy) to explore the feedback mechanisms, reciprocal effects, surprises, and threshold mechanisms, taking place in floodplain systems. The outcomes of the study enable a better understanding of how the occurrences of floods shape human developments while, at the same time, human activities shape the magnitude and frequency of floods. The presentation also discusses the opportunities offered by

  6. A Learning-Style Theory for Understanding Autistic Behaviors

    Science.gov (United States)

    Qian, Ning; Lipkin, Richard M.

    2011-01-01

    Understanding autism's ever-expanding array of behaviors, from sensation to cognition, is a major challenge. We posit that autistic and typically developing brains implement different algorithms that are better suited to learn, represent, and process different tasks; consequently, they develop different interests and behaviors. Computationally, a continuum of algorithms exists, from lookup table (LUT) learning, which aims to store experiences precisely, to interpolation (INT) learning, which focuses on extracting underlying statistical structure (regularities) from experiences. We hypothesize that autistic and typical brains, respectively, are biased toward LUT and INT learning, in low- and high-dimensional feature spaces, possibly because of their narrow and broad tuning functions. The LUT style is good at learning relationships that are local, precise, rigid, and contain little regularity for generalization (e.g., the name–number association in a phonebook). However, it is poor at learning relationships that are context dependent, noisy, flexible, and do contain regularities for generalization (e.g., associations between gaze direction and intention, language and meaning, sensory input and interpretation, motor-control signal and movement, and social situation and proper response). The LUT style poorly compresses information, resulting in inefficiency, sensory overload (overwhelm), restricted interests, and resistance to change. It also leads to poor prediction and anticipation, frequent surprises and over-reaction (hyper-sensitivity), impaired attentional selection and switching, concreteness, strong local focus, weak adaptation, and superior and inferior performances on simple and complex tasks. The spectrum nature of autism can be explained by different degrees of LUT learning among different individuals, and in different systems of the same individual. Our theory suggests that therapy should focus on training autistic LUT algorithm to learn regularities

  7. A learning-style theory for understanding autistic behaviors

    Directory of Open Access Journals (Sweden)

    Ning eQian

    2011-08-01

    Full Text Available Understanding autism’s ever-expanding array of behaviors, from sensation to cognition, is a major challenge. We posit that autistic and typically-developing brains implement different algorithms that are better suited to learn, represent, and process different tasks; consequently, they develop different interests and behaviors. Computationally, a continuum of algorithms exists, from lookup-table (LUT learning, which aims to store experiences precisely, to interpolation (INT learning, which focuses on extracting underlying statistical structure (regularities from experiences. We hypothesize that autistic and typical brains, respectively, are biased toward LUT and INT learning, in low and high dimensional feature spaces, possibly because of their narrow and broad tuning functions. The LUT style is good at learning relationships that are local, precise, rigid, and contain little regularity for generalization (e.g., the name-number association in a phonebook. However, it is poor at learning relationships that are context dependent, noisy, flexible, and do contain regularities for generalization (e.g., associations between gaze direction and intention, language and meaning, sensory input and interpretation, motor-control signal and movement, and social situation and proper response. The LUT style poorly compresses information, resulting in inefficiency, sensory overload (overwhelm, restricted interests, and resistance to change. It also leads to poor prediction and anticipation, frequent surprises and over-reaction (hyper-sensitivity, impaired attentional selection and switching, concreteness, strong local focus, weak adaptation, and superior and inferior performances on simple and complex tasks. The spectrum nature of autism can be explained by different degrees of LUT learning among different individuals, and in different systems of the same individual. Our theory suggests that therapy should focus on training autistic LUT algorithm to learn

  8. A Contextual Behavior Science Framework for Understanding How Behavioral Flexibility Relates to Anxiety.

    Science.gov (United States)

    Palm Reed, Kathleen M; Cameron, Amy Y; Ameral, Victoria E

    2017-09-01

    There is a growing literature focusing on the emerging idea that behavioral flexibility, rather than particular emotion regulation strategies per se, provides greater promise in predicting and influencing anxiety-related psychopathology. Yet this line of research and theoretical analysis appear to be plagued by its own challenges. For example, middle-level constructs, such as behavioral flexibility, are difficult to define, difficult to measure, and difficult to interpret in relation to clinical interventions. A key point that some researchers have made is that previous studies examining flexible use of emotion regulation strategies (or, more broadly, coping) have failed due to a lack of focus on context. That is, examining strategies in isolation of the context in which they are used provides limited information on the suitability, rigid adherence, or effectiveness of a given strategy in that situation. Several of these researchers have proposed the development of new models to define and measure various types of behavioral flexibility. We would like to suggest that an explanation of the phenomenon already exists and that we can go back to our behavioral roots to understand this phenomenon rather than focusing on defining and capturing a new process. Indeed, thorough contextual behavioral analyses already yield a useful account of what has been observed. We will articulate a model explaining behavioral flexibility using a functional, contextual framework, with anxiety-related disorders as an example.

  9. Understanding Social Learning Behaviors via a Virtual Field Trip

    Directory of Open Access Journals (Sweden)

    Xin Bai

    2014-06-01

    Full Text Available This is a multidisciplinary study investigating how a virtual rather than face-to-face field trip can be conducted in a real-world setting and how students respond to such a social learning opportunity. Our participants followed a story of a stroke patient at her virtual home and in a virtual hospital via a teaching vignette. They were then given a new case and got on a virtual trip via a multiuser virtual environment. They played the roles of patients, relatives, doctors, or nurses, experiencing the emotional, physical, or social impacts those stakeholders may go through. Our study finds the overall participation of the Virtual Group is 50% more than the Text Group. Although the Virtual Group generates much more nodes in total, they focused much less on knowledge sharing and comparing than the Text Group (46 vs. 67, but more on other higher-level aspects of social interactions, such as knowledge discovery (57 vs. 42, co-construction (66 vs. 39, testing and modification (58 vs. 24 and application of newly constructed meaning (60 vs. 16. Analysis of students’ virtual field activities and in-depth discussions of important issues implied are included to help understand social learning behaviors during a virtual field trip. Sustainability of such systems is discussed.

  10. AIDS, behavior, and culture: understanding evidence-based prevention

    National Research Council Canada - National Science Library

    Green, Edward C; Ruark, Allison Herling

    2011-01-01

    .... Arguing for a behavior-based approach, the authors make the case that the most effective programs are those that encourage fundamental behavioral changes such as faithfulness, avoidance of concurrent...

  11. Magnetic behavior of partially exchange-coupled particles

    International Nuclear Information System (INIS)

    Oliva, M.I.; Bercoff, P.G.; Bertorello, H.R.

    2005-01-01

    A system of particle pairs with partial exchange coupling is studied, considering identical particles and a fixed angle between their anisotropy axes. The energy of each pair is calculated in terms of the extent of interaction, β, as a function of the applied demagnetizing field. Using the probability per unit time for the inversion of magnetization, the coercive field H c and the viscosity S of the system are calculated. An unexpected result is that fully coupled particles are more stable against temperature than the uncoupled particles

  12. Quality Improvement in Hospitals: Identifying and Understanding Behaviors

    Directory of Open Access Journals (Sweden)

    Lukasz M. Mazur

    2012-01-01

    Full Text Available Improving operational performance in hospitals is complicated, particularly if process improvement requires complex behavioral changes. Using single-loop and double-loop learning theory as a foundation, the purpose of this research is to empirically uncover key improvement behaviors and the factors that may be associated with such behaviors in hospitals. A two-phased approach was taken to collect data regarding improvement behaviors and associated factors, and data analysis was conducted using methods proposed by grounded theorists. The contributions of this research are twofold. First, five key behaviors related to process improvement are identified, namely Quick Fixing, Initiating, Conforming, Expediting, and Enhancing. Second, based on these observed behaviors, a set of force field diagrams is developed to structure and organize possible factors that are important to consider when attempting to change improvement behaviors. This begins to fill the gap in the knowledge about what factors drive effective improvement efforts in hospital settings.

  13. Assessing Freshman Engineering Students' Understanding of Ethical Behavior.

    Science.gov (United States)

    Henslee, Amber M; Murray, Susan L; Olbricht, Gayla R; Ludlow, Douglas K; Hays, Malcolm E; Nelson, Hannah M

    2017-02-01

    Academic dishonesty, including cheating and plagiarism, is on the rise in colleges, particularly among engineering students. While students decide to engage in these behaviors for many different reasons, academic integrity training can help improve their understanding of ethical decision making. The two studies outlined in this paper assess the effectiveness of an online module in increasing academic integrity among first semester engineering students. Study 1 tested the effectiveness of an academic honesty tutorial by using a between groups design with a Time 1- and Time 2-test. An academic honesty quiz assessed participants' knowledge at both time points. Study 2, which incorporated an improved version of the module and quiz, utilized a between groups design with three assessment time points. The additional Time 3-test allowed researchers to test for retention of information. Results were analyzed using ANCOVA and t tests. In Study 1, the experimental group exhibited significant improvement on the plagiarism items, but not the total score. However, at Time 2 there was no significant difference between groups after controlling for Time 1 scores. In Study 2, between- and within-group analyses suggest there was a significant improvement in total scores, but not plagiarism scores, after exposure to the tutorial. Overall, the academic integrity module impacted participants as evidenced by changes in total score and on specific plagiarism items. Although future implementation of the tutorial and quiz would benefit from modifications to reduce ceiling effects and improve assessment of knowledge, the results suggest such tutorial may be one valuable element in a systems approach to improving the academic integrity of engineering students.

  14. Behavior of Ag nanoparticles in soil: Effects of particle surface coating, aging and sewage sludge amendment

    International Nuclear Information System (INIS)

    Whitley, Annie R.; Levard, Clément; Oostveen, Emily; Bertsch, Paul M.; Matocha, Chris J.; Kammer, Frank von der; Unrine, Jason M.

    2013-01-01

    This study addressed the relative importance of particle coating, sewage sludge amendment, and aging on aggregation and dissolution of manufactured Ag nanoparticles (Ag MNPs) in soil pore water. Ag MNPs with citrate (CIT) or polyvinylpyrrolidone (PVP) coatings were incubated with soil or municipal sewage sludge which was then amended to soil (1% or 3% sludge (w/w)). Pore waters were extracted after 1 week and 2 and 6 months and analyzed for chemical speciation, aggregation state and dissolution. Ag MNP coating had profound effects on aggregation state and partitioning to pore water in the absence of sewage sludge, but pre-incubation with sewage sludge negated these effects. This suggests that Ag MNP coating does not need to be taken into account to understand fate of AgMNPs applied to soil through biosolids amendment. Aging of soil also had profound effects that depended on Ag MNP coating and sludge amendment. -- Highlights: •Silver nanoparticle coating affects fate in unamended soils. •Citrated coated silver nanoparticles could be found in pore water for up to six months. •Pre-incubation of silver nanoparticles in sewage sludge negated effects of surface coating. •Weathered or reprecipitated particles found in pore water for up to two months in sludge amended soils. •Particle surface coating, sewage sludge amendment and aging all have important impacts. -- Behavior of manufactured silver nanoparticles in soil depends on surface coating, contact with sewage sludge, and aging

  15. Fine and nanometer scaled particle behavior characterization and control for sustainable energy and environmental technology

    Energy Technology Data Exchange (ETDEWEB)

    Hidehiro Kamiya; Mayumi Tsukada; Wuled Lenggoro; Wladyslaw W. Szymanski [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    2008-07-01

    Characterization and control of fine and nanometer scaled particles are essential technological fundamentals for understanding and development of various approaches concerned with sustainable energy and environmental technology, for example, PM10/PM2.5 and nanoparticle emission, clean and high efficiency power generation systems from biomass and solid waste combustion. The standard measuring methods for PM10/PM2.5 and nanoparticle emission behavior from stationary sources, such as coal-fired power plants and waste incinerators, have been discussed in ISO and numerous countries. However, it is difficult to evaluate the actual emission amount and particle size distribution, such as condensable suspended particulate matter, condensable SPM, which is nucleated and grow during cooling and diluting process from flue to atmosphere. High temperature gas cleaning using rigid ceramic filters is an important technology to develop high efficiency power generation system. In this paper, based on the review of background and recent research works of each subject, mass concentration measurement method of PM10/PM2.5 and size distribution of condensable SPM from stationary sources are introduced. Subsequently, research results with focus on ash adhesion behavior characterization and control for the development of dust collection and gas cleaning technology at high temperature conditions in high efficiency power generation systems by coal, biomass and solid waste combustion are presented. 12 refs., 7 figs., 3 tabs.

  16. Dynamic behavior of microscale particles controlled by standing bulk acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Greenhall, J.; Raeymaekers, B., E-mail: bart.raeymaekers@utah.edu [Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Guevara Vasquez, F. [Department of Mathematics, University of Utah, Salt Lake City, Utah 84112 (United States)

    2014-10-06

    We analyze the dynamic behavior of a spherical microparticle submerged in a fluid medium, driven to the node of a standing bulk acoustic wave created by two opposing transducers. We derive the dynamics of the fluid-particle system taking into account the acoustic radiation force and the time-dependent and time-independent drag force acting on the particle. Using this dynamic model, we characterize the transient and steady-state behavior of the fluid-particle system as a function of the particle and fluid properties and the transducer operating parameters. The results show that the settling time and percent overshoot of the particle trajectory are dependent on the ratio of the acoustic radiation force and time-independent damping force. In addition, we show that the particle oscillates around the node of the standing wave with an amplitude that depends on the ratio of the time-dependent drag forces and the particle inertia.

  17. "I Got Your Back": Friends' Understandings regarding College Student Spring Break Behavior

    Science.gov (United States)

    Patrick, Megan E.; Morgan, Nicole; Maggs, Jennifer L.; Lefkowitz, Eva S.

    2011-01-01

    Behaviors that pose threats to safety and health, including binge drinking and unprotected sex, increase during a week-long break from university. Understandings with peers regarding these behaviors may be important for predicting behavior and related harms. College students (N = 651; 48% men) reported having understandings with their friends…

  18. Understanding the atmospheric measurement and behavior of perfluorooctanoic acid.

    Science.gov (United States)

    Webster, Eva M; Ellis, David A

    2012-09-01

    The recently reported quantification of the atmospheric sampling artifact for perfluorooctanoic acid (PFOA) was applied to existing gas and particle concentration measurements. Specifically, gas phase concentrations were increased by a factor of 3.5 and particle-bound concentrations by a factor of 0.1. The correlation constants in two particle-gas partition coefficient (K(QA)) estimation equations were determined for multiple studies with and without correcting for the sampling artifact. Correction for the sampling artifact gave correlation constants with improved agreement to those reported for other neutral organic contaminants, thus supporting the application of the suggested correction factors for perfluorinated carboxylic acids. Applying the corrected correlation constant to a recent multimedia modeling study improved model agreement with corrected, reported, atmospheric concentrations. This work confirms that there is sufficient partitioning to the gas phase to support the long-range atmospheric transport of PFOA. Copyright © 2012 SETAC.

  19. Guest Editors’ Introduction On Understanding Ethical Behavior and Decision Making

    NARCIS (Netherlands)

    D. de Cremer (David); D.M. Mayer (David); M. Schminke (Marshall)

    2010-01-01

    textabstractBehavioral ethics is an emerging field that takes an empirical, social scientific approach to the study of business ethics. In this special issue, we include six articles that fall within the domain of behavioral ethics and that focus on three themes—moral awareness, ethical decision

  20. Understanding User Behavioral Patterns in Open Knowledge Communities

    Science.gov (United States)

    Yang, Xianmin; Song, Shuqiang; Zhao, Xinshuo; Yu, Shengquan

    2018-01-01

    Open knowledge communities (OKCs) have become popular in the era of knowledge economy. This study aimed to explore how users collaboratively create and share knowledge in OKCs. In particular, this research identified the behavior distribution and behavioral patterns of users by conducting frequency distribution and lag sequential analyses. Some…

  1. Understanding rapid theoretical change in particle physics: a month-by-month co-citation analysis

    International Nuclear Information System (INIS)

    Sullivan, D.; Koester, D.; White, D.H.; Kern, R.

    1979-01-01

    While co-citation analysis has proved a powerful tool in the study of changes in intellectual foci in science, no one has ever used the technique to study very rapid changes in the theoretical structure of a scientific field. This paper presents month-by-month co-citation analyses of key phases in the weak-electromagnetic unification research program within particle physics, and shows that these analyses capture and illuminate very rapid intellectual changes. These data provide yet another illustration of the utility of co-citation analysis for understanding the history of science. 8 figures

  2. Particle behavior in an ECR plasma etch tool

    International Nuclear Information System (INIS)

    Blain, M.G.; Tipton, G.D.; Holber, W.M.; Westerfield, P.L.; Maxwell, K.L.

    1993-01-01

    Sources of particles in a close-coupled electron cyclotron resonance (ECR) polysilicon plasma etch source include flaking of films deposited on chamber surfaces, and shedding of material from electrostatic wafer chucks. A large, episodic increase in the number of particles added to a wafer in a clean system is observed more frequently for a plasma-on than for a gas-only source condition. For polymer forming process conditions, particles were added to wafers by a polymer film which was observed to fracture and flake away from chamber surfaces. The presence of a plasma, especially when rf bias is applied to the wafer, caused more particles to be ejected from the walls and added to wafers than the gas-only condition; however, no significant influence was observed with different microwave powers. A study of effect of electrode temperatures on particles added showed that thermophoretic forces are not significant for this ECR configuration. Particles originating from the electrostatic chuck were observed to be deposited on wafers in much larger numbers in the presence of the plasma as compared to gas-only conditions

  3. CFD modeling of particle behavior in supersonic flows with strong swirls for gas separation

    DEFF Research Database (Denmark)

    Yang, Yan; Wen, Chuang

    2017-01-01

    . The results showed that the gas flow was accelerated to supersonic velocity, and created the low pressure and temperature conditions for gas removal. Most of the particles collided with the walls or entered into the liquid-collection space directly, while only a few particles escaped together with the gas......The supersonic separator is a novel technique to remove the condensable components from gas mixtures. But the particle behavior is not well understood in this complex supersonic flow. The Discrete Particle Method was used here to study the particle motion in supersonic flows with a strong swirl...

  4. Understanding the synthesis of mesoporous silica particles by evaporation induced self assembly

    Science.gov (United States)

    Rathod, Shailendra B.

    2007-12-01

    Evaporation-induced self-assembly (EISA) of amphiphilic molecules within aerosol droplets is an attractive method for synthesis of mesoporous silica particles. The aim of this research was to demonstrate synthetic methodologies to develop novel particle architectures using this technique, and to understand the influence of the competing dynamics within an evaporating droplet undergoing EISA on the particle morphology and mesostructure. Experiments were conducted to control particle characteristics. Particle size and distribution was varied by varying the size and distribution of starting droplets. The compressed gas atomizer, TSI 3076, gave a roughly micron-sized droplets with a polydisperse population, whereas the vibrating orifice aerosol generator (VOAG), TSI 3450, gave a highly monodisperse droplet population when orifices of diameters 10 mum and 20 mum were used. The mesopore size and mesostructure ordering were varied by employing amphiphiles of different geometry and by the use of 1,2,3-trimethylbenzene, a pore-swelling agent. The extent of ordering was influenced by factors that govern the rates of reactions of the silica precursors relative to the rates of amphiphile self-assembly. These factors included acid concentration, the alkyl group in the tetraalkoxysilane precursor, the time for which the sol was aged before droplet generation, and CTAB/Si ratio in the starting sol. Experiments and simulation studies were carried out for particles made using CTAB as the templating agent and TMB as a pore-swelling agent. Analysis of these experiments was used to get insight into the three main dynamic processes occurring inside these droplets: evaporation of the volatile species, amphiphile self-assembly and phase transformation, and hydrolysis and condensation reactions of the silica precursor species. Pore swelling was observed for particles made using the VOAG. Particles made using the 10 mum orifice retained their hexagonal mesostructure upon addition of TMB in

  5. Deformation Behaviors of Cold-Sprayed WC-Co Particles

    Science.gov (United States)

    Ji, Gang-Chang; Chen, Xiao; Wang, Hong-Tao; Bai, Xiao-Bo; Dong, Zeng-Xiang

    2015-08-01

    In the present work, the WC-Co particles with different sizes and contents of WC particle were deposited on the stainless and WC-Co substrate in different accelerating gas temperatures. The deformation mechanisms of incident WC-Co particles and impacted substrates, and especially their interactions were characterized via scan electron microscopy (SEM) observations of both surface morphologies and cross-sectional microstructures of individual splats, and splat/substrate interface with the assistance of focus ion beam (FIB). The effects of feedstock powder structure, i.e., WC particle size and Co content, and temperature of accelerating gas on plastic deformation were comprehensively studied. It was revealed that the splats on stainless steel exhibited ellipsoid shape with a comparative integrated contour similar to original powder, and there were some revers on substrate around splats. In contrast, splats on WC-Co substrate exhibited more flattened pie shape with some ejectas on its periphery in the radial direction. The more curved interface convex to stainless steel substrate appeared compared to that of WC-Co substrate. Deformation of WC-Co splats was enhanced by the increment of substrate hardness and increment of Co binder and reduction of WC size of incident particles.

  6. A New Understanding of Particles by G-Flow Interpretation of Differential Equation

    Directory of Open Access Journals (Sweden)

    Mao L.

    2015-07-01

    Full Text Available Applying mathematics to the understanding of particles classically with an assumption that if the variables t and x 1 , x 2 , x 3 hold with a system of dynamical equations (1.4, then they are a point ( t , x 1 , x 2 , x 3 in R 4 . However, if we put off this assumption, how can we interpret the solution space of equations? And are the se resultants important for understanding the world? Recently, the author extended Ban ach and Hilbert spaces on a topological graph to introduce −→ G -flows and showed that all such flows on a topological graph −→ G also form a Banach or Hilbert space, which enables one to find t he multiverse solution of these equations on −→ G . Applying this result, this paper discusses the −→ G -flow solutions on Schrödinger equation, Klein-Gordon equation and Dirac equation, i.e., the field equations of particles, bosons or fermions, answers previous questions by ”yes“, and establishes the many world interpretation of quantum mechanics of H. Everett by purely mathematics in logic, i.e., mathematical combinatorics.

  7. Numerical analysis of jet breakup behavior using particle method

    International Nuclear Information System (INIS)

    Shibata, Kazuya; Koshizuka, Seiichi; Oka, Yoshiaki

    2002-01-01

    A continuous jet changes to droplets where jet breakup occurs. In this study, two-dimensional numerical analysis of jet breakup is performed using the MPS method (Moving Particle Semi-implicit Method) which is a particle method for incompressible flows. The continuous fluid surrounding the jet is neglected. Dependencies of the jet breakup length on the Weber number and the Froude number agree with the experiment. The size distribution of droplets is in agreement with the Nukiyama-Tanasawa distribution which has been widely used as an experimental correlation. Effects of the Weber number and the Froude number on the size distribution are also obtained. (author)

  8. Superplastic behavior in Mg-Zn-Y alloy with dispersed quasicrystal phase particles

    Energy Technology Data Exchange (ETDEWEB)

    Somekawa, Hidetoshi; Singh, Alok; Mukai, Toshiji [Structural Metals Center, National Institute for Materials Science, Tsukuba, Ibaraki (Japan)

    2009-10-15

    An Mg-Zn-Y alloy with a dispersion of quasicrystal phase particles showed low-temperature superplastic behavior, and the dominant deformation process was grain boundary sliding. Observations of the deformed microstructure showed that the quasicrystal phase particles were an obstacle to dislocation movements; the kinetics of the superplastic behavior were lower than those of a conventional magnesium alloy. This alloy also demonstrated a high possibility for secondary forming - i.e., superplastic forging. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  9. Image Schemas in Verb-Particle Constructions: Evidence from a Behavioral Experiment

    Science.gov (United States)

    Yang, Tangfeng

    2016-01-01

    Cognitive linguists claim that verb-particle constructions are compositional and analyzable, and that the particles contribute to the overall meaning in the form of image schemas. This article examined this claim with a behavioral experiment, in which participants were asked to judge the sensibility of short sentences primed by image-schematic…

  10. LD, interpersonal understanding, and social behavior in the classroom.

    Science.gov (United States)

    Kravetz, S; Faust, M; Lipshitz, S; Shalhav, S

    1999-01-01

    This study used Baron and Kenny's (1986) criteria for mediation to investigate the extent to which interpersonal understanding mediates the relation between learning disabilities (LD) and social adaptation in the classroom. Twenty-two children with and 22 children without a diagnosis of LD completed a semistructured developmental clinical interview measure of interpersonal understanding. They were also rated by their fourth- and fifth-grade teachers on a measure of social adaptation in the classroom. Interpersonal understanding and social adaptation in the classroom were found to be positively correlated. Children with LD exhibited less interpersonal understanding and social adaptation. Although this group difference on social adaptation was greatly reduced when interpersonal understanding was statistically controlled, it remained statistically significant. These results suggest that reduced social adaptation in the classroom and lower interpersonal understanding are both associated with a diagnosis of LD. However, they do not conclusively support the claim that interpersonal understanding mediates the relation between LD and social adaptation. Thus, whether the social difficulties of people with LD stem from the same complex phenomena that produce these people's learning problems remains an open question.

  11. Understanding driver behavior at grade crossings through signal detection theory.

    Science.gov (United States)

    2013-01-01

    This report uses signal detection theory (SDT) to model motorists decisionmaking strategies at grade crossings in order to understand the factors that influence such decisions and to establish a framework for evaluating the impact of proposed coun...

  12. Understanding driver behavior at grade crossings through signal detection theory.

    Science.gov (United States)

    2013-01-31

    This report uses signal detection theory (SDT) to model motorists decisionmaking strategies at grade crossings in order to understand the factors that influence such decisions and to establish a framework for evaluating the impact of proposed coun...

  13. Viscoelastic materials with anisotropic rigid particles: stress-deformation behavior

    NARCIS (Netherlands)

    Sagis, L.M.C.; Linden, van der E.

    2001-01-01

    In this paper we have derived constitutive equations for the stress tensor of a viscoelastic material with anisotropic rigid particles. We have assumed that the material has fading memory. The expressions are valid for slow and small deformations from equilibrium, and for systems that are nearly

  14. Swarming behavior of gradient-responsive Brownian particles in a porous medium

    Science.gov (United States)

    Grančič, Peter; Štěpánek, František

    2012-07-01

    Active targeting by Brownian particles in a fluid-filled porous environment is investigated by computer simulation. The random motion of the particles is enhanced by diffusiophoresis with respect to concentration gradients of chemical signals released by the particles in the proximity of a target. The mathematical model, based on a combination of the Brownian dynamics method and a diffusion problem is formulated in terms of key parameters that include the particle diffusiophoretic mobility and the signaling threshold (the distance from the target at which the particles release their chemical signals). The results demonstrate that even a relatively simple chemical signaling scheme can lead to a complex collective behavior of the particles and can be a very efficient way of guiding a swarm of Brownian particles towards a target, similarly to the way colonies of living cells communicate via secondary messengers.

  15. Toward improving our application and understanding of crown fire behavior

    Science.gov (United States)

    Martin E. Alexander; Miguel G. Cruz; Nicole M. Vaillant

    2014-01-01

    The suggestion has been made that most wildland fire operations personnel base their expectations of how a fire will behave largely on experience and, to a lesser extent, on guides to predicting fire behavior (Burrows 1984). Experienced judgment is certainly needed in any assessment of wildland fire potential but it does have its limitations. The same can be said for...

  16. Understanding Transnational African Migrants' Perspectives of Dietary Behavior.

    Science.gov (United States)

    Ibe-Lamberts, Kelechi; Tshiswaka, Daudet Ilunga; Osideko, Anuolwaupo; Schwingel, Andiara

    2016-10-28

    Dietary behaviors serve as determinants for chronic diseases such as hypertension across various ethnicities worldwide and within the USA. We investigated dietary perspectives specifically for US transnational African migrants, a migrant cohort subset of individuals who maintain cross-border ties with their indigenous communities of origin. Using PEN-3 model, focus group interviews with 14 transnational African migrants (seven males and seven females) were conducted in Chicago to explore the perceptions of dietary behavior in regard to chronic disease risk factors among our target population. The findings underscore that transnational African migrants maintain strong ties with their African community of origin, impacting dietary behaviors and attitudes. Further, transnational African migrants maintain traditional dishes through their connections. Despite the ability to import African traditional foods through personal connections, African migrants face a challenge in maintaining culture yet conforming to norms of acculturation. Results from this study serve to advocate for further exploration of the interaction between African migrant dietary behaviors and risk factors to chronic diseases.

  17. Behavioral accident avoidance science : understanding response in collision incipient conditions

    NARCIS (Netherlands)

    Hancock, P.A.; Ridder, S.N. de

    2003-01-01

    Road traffic accidents are the single greatest cause of fatality in the workplace and the primary cause of all accidental death in the U.S. to the age of seventy-eight. However, behavioral analysis of response in the final seconds and milliseconds before collision has been a most difficult

  18. Children's Behavior toward and Understanding of Robotic and Living Dogs

    Science.gov (United States)

    Melson, Gail F.; Kahn, Peter H., Jr.; Beck, Alan; Friedman, Batya; Roberts, Trace; Garrett, Erik; Gill, Brian T.

    2009-01-01

    This study investigated children's reasoning about and behavioral interactions with a computationally sophisticated robotic dog (Sony's AIBO) compared to a live dog (an Australian Shepherd). Seventy-two children from three age groups (7-9 years, 10-12 years, and 13-15 years) participated in this study. Results showed that more children…

  19. Health Behavior Change Challenge: Understanding Stages of Change

    Science.gov (United States)

    Sullivan, Claire F.

    2011-01-01

    This semester-long activity requires students to reflect on their own strengths and weaknesses in attempting to take on a personally meaningful health behavior change challenge. This assignment affords them the opportunity to take a deeper look at theory and health concepts learned throughout the semester and to see how it has informed their own…

  20. Understanding patients' behavioral intentions: evidence from Iran's private hospitals industry.

    Science.gov (United States)

    Zarei, Ehsan; Arab, Mohammad; Tabatabaei, Seyed Mahmoud Ghazi; Rashidian, Arash; Forushani, Abbas Rahimi; Khabiri, Roghayeh

    2014-01-01

    In the ever-increasing competitive market of private hospital industry, creating a strong relationship with the customers that shapes patients' loyalty has been considered a key factor in obtaining market share. The purpose of this paper is to test a model of customer loyalty among patients of private hospitals in Iran. This cross-sectional study was carried out in Tehran, the capital of the Islamic Republic of Iran in 2010. The study samples composed of 969 patients who were consecutively selected from eight private hospitals. The survey instrument was designed based on a review of the related literature and included 36 items. Data analysis was performed using structural equation modeling. For the service quality construct, three dimensions extracted: Process, interaction, and environment. Both process and interaction quality had significant effects on perceived value. Perceived value along with the process and interaction quality were the most important antecedents of patient overall satisfaction. The direct effect of the process and interaction quality on behavioral intentions was insignificant. Perceived value and patient overall satisfaction were the direct antecedents of patient behavioral intentions and the mediators between service quality and behavioral intentions. Environment quality of service delivery had no significant effect on perceived value, overall satisfaction, and behavioral intentions. Contrary to previous similar studies, the role of service quality was investigated not in a general sense, but in the form of three types of qualities including quality of environment, quality of process, and quality of interaction.

  1. Understanding Homophobic Behavior and Its Implications for Policy and Practice

    Science.gov (United States)

    Poteat, V. Paul; Russell, Stephen T.

    2013-01-01

    In this article, we consider recent advances in scholarship on homophobic bullying, and implications for policy and practice. We first consider toward whom homophobic behavior is directed, drawing attention to the nuances among LGBT youth, and the realities of homophobic bullying for heterosexual or straight youth. We review the correlates or…

  2. The immersion freezing behavior of ash particles from wood and brown coal burning

    Directory of Open Access Journals (Sweden)

    S. Grawe

    2016-11-01

    Full Text Available It is generally known that ash particles from coal combustion can trigger ice nucleation when they interact with water vapor and/or supercooled droplets. However, data on the ice nucleation of ash particles from different sources, including both anthropogenic and natural combustion processes, are still scarce. As fossil energy sources still fuel the largest proportion of electric power production worldwide, and biomass burning contributes significantly to the global aerosol loading, further data are needed to better assess the ice nucleating efficiency of ash particles. In the framework of this study, we found that ash particles from brown coal (i.e., lignite burning are up to 2 orders of magnitude more ice active in the immersion mode below −32 °C than those from wood burning. Fly ash from a coal-fired power plant was shown to be the most efficient at nucleating ice. Furthermore, the influence of various particle generation methods on the freezing behavior was studied. For instance, particles were generated either by dispersion of dry sample material, or by atomization of ash–water suspensions, and then led into the Leipzig Aerosol Cloud Interaction Simulator (LACIS where the immersion freezing behavior was examined. Whereas the immersion freezing behavior of ashes from wood burning was not affected by the particle generation method, it depended on the type of particle generation for ash from brown coal. It was also found that the common practice of treating prepared suspensions in an ultrasonic bath to avoid aggregation of particles led to an enhanced ice nucleation activity. The findings of this study suggest (a that ash from brown coal burning may influence immersion freezing in clouds close to the source and (b that the freezing behavior of ash particles may be altered by a change in sample preparation and/or particle generation.

  3. Neutral Particle Analyzer Measurements of Ion Behavior in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S.S. Medley; R.E. Bell; D.S. Darrow; A.L. Roquemore

    2002-02-06

    Initial results obtained with the Neutral Particle Analyzer (NPA) diagnostic on the National Spherical Torus Experiment (NSTX) are presented. Magnetohydrodynamic activity and reconnection events cause depletion of the deuterium energetic ion distribution created by neutral-beam injection. Adding High Harmonic Fast Wave Heating to neutral-beam-heated discharges results in the generation of an energetic ion tail above the beam injection energy. NPA measurements of the residual hydrogen ion temperature are in good agreement with those from recombination spectroscopy.

  4. Understanding the heavy-tailed dynamics in human behavior.

    Science.gov (United States)

    Ross, Gordon J; Jones, Tim

    2015-06-01

    The recent availability of electronic data sets containing large volumes of communication data has made it possible to study human behavior on a larger scale than ever before. From this, it has been discovered that across a diverse range of data sets, the interevent times between consecutive communication events obey heavy-tailed power law dynamics. Explaining this has proved controversial, and two distinct hypotheses have emerged. The first holds that these power laws are fundamental, and arise from the mechanisms such as priority queuing that humans use to schedule tasks. The second holds that they are statistical artifacts which only occur in aggregated data when features such as circadian rhythms and burstiness are ignored. We use a large social media data set to test these hypotheses, and find that although models that incorporate circadian rhythms and burstiness do explain part of the observed heavy tails, there is residual unexplained heavy-tail behavior which suggests a more fundamental cause. Based on this, we develop a quantitative model of human behavior which improves on existing approaches and gives insight into the mechanisms underlying human interactions.

  5. Microstructure and strain rate effects on the mechanical behavior of particle reinforced epoxy-based reactive materials

    Science.gov (United States)

    White, Bradley William

    the effects of microstructure on their mechanical behavior at strain-rates from 10-4 to 104 s-1. The dynamic response to compressive loads was obtained using the split Hopkinson pressure bar and Taylor rod-on-anvil impact experimental configurations. Microstructures from each composite and at each strain rate were analyzed to determine the amount of particle strain as a function of bulk strain and strain rate. Also of key interest to this study are the epoxy matrix-metallic particle and particle-particle interactions at the mesoscale under dynamic compressive loading conditions. The composite microstructure is highly heterogeneous at the mesoscale and the high contrasting properties of the individual constituents drive localized deformations that are often more pronounced than those in the bulk material. To examine the mesoscale response to dynamic loading conditions, computational simulations of representative microstructures of select composites were conducted. The stress and strain localization effects were characterized at the mesoscale and the bulk mechanical behavior was decomposed into the individual contributions of the constituent phases. The analysis provided a greater understanding of the mechanisms associated with particle deformation and stress transfer between phases, and their influence on the overall mechanical response of polymer matrix composites reinforced with metallic particles. The influence of strain rate behavior of epoxy is shown to cause a strain rate dependent deformation response of reinforcement particle phases that are typically strain rate independent.

  6. Understanding Chinese international college and university students' physical activity behavior

    Directory of Open Access Journals (Sweden)

    Zi Yan

    2015-06-01

    Conclusion: Understanding factors that influence PA among Chinese international students is an important step in the process of promoting their long-term health and wellbeing. Designing program that address the identified key factors may help colleges and universities achieve this goal.

  7. Using Story to Help Student Understanding of Gas Behavior

    Science.gov (United States)

    Wiebe, Rick; Stinner, Arthur

    2010-01-01

    Students tend to have a poor understanding of the concept of gas pressure. Usually, gas pressure is taught in terms of the various formulaic gas laws. The development of the concept of gas pressure according to the early Greeks did not include the concept of a vacuum. It was not for another 2000 years that Torricelli proposed that a vacuum can…

  8. Particle characteristics and reduction behavior of synthetic magnetite

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, Wegdan [Physics Department, Faculty of Science, Alexandria University, Alexandria 21511 (Egypt); Zaki, Mohamed I., E-mail: mizaki@link.net [Chemistry Department, Faculty of Science, Minia University, El-Minia 61519 (Egypt); Fouad, Nasr E.; Mekhemer, Gamal A.H. [Chemistry Department, Faculty of Science, Minia University, El-Minia 61519 (Egypt)

    2014-04-15

    Two samples (S1 and S2) of magnetite were synthesized, using two different methods, and characterized by means of X-ray powder diffractometry, infrared and Mössbauer spectroscopy, N{sub 2} sorptiometry and electron microscopy. Particles of sample-S1 were found to be loosely agglomerated, micro-sized spheroids (200–350 nm) composed almost solely of highly aggregated (fused) crystallites (size averaged at 35 nm) of cubic-Fe{sub 3}O{sub 4}. In contrast, particles of sample-S2 were strongly agglomerated, nano-sized spheroids (25–30 nm) composed of slightly aggregated crystallites (size averaged at 11 nm) of cubic-Fe{sub 3}O{sub 4} and noncrystalline domains made-up of FeO(OH) species. Temperature-programed reduction (TPR) profiles obtained for the two samples were similar in monitoring two peaks at >450 °C assignable to a two-step reduction of Fe{sub 3}O{sub 4} (→FeO→Fe), but different in monitoring a peak at<450 °C only for the reduction of FeO(OH) (→Fe{sub 3}O{sub 4}) contained in sample-S2. However, curve fitting analysis of the TPR profiles and molecular stoichiometry calculations based on amounts of hydrogen consumed revealed that the two-step reduction of Fe{sub 3}O{sub 4} is not straightforward. That is by resolving two consecutive pathways for each step and, hence, nonstoichiometric intermediate products whose composition was found to be critically controlled by the composition of the reducing gas atmosphere (5 or 80% H{sub 2}/N{sub 2}) and characteristics of the starting sample particles (chemical and phase composition, and, but to lesser extents, the agglomeration and average size). - Highlights: • Nano or micro, pure Fe{sub 3}O{sub 4} particles are H{sub 2}-reduced in two steps (→FeO→Fe) at >450 °C. • FeO(OH)-impure particles exhibit a third reduction step (FeO(OH)→Fe{sub 3}O{sub 4}) at <450 °C. • FeO disproportion and related autocatalytic effects complicate the reduction course. • Consequently, each of the Fe{sub 3}O{sub 4

  9. Individual Differences in Toddlers’ Social Understanding & Prosocial Behavior: Disposition or Socialization?

    Directory of Open Access Journals (Sweden)

    Rebekkah Lauren Gross

    2015-05-01

    Full Text Available We examined how individual differences in social understanding contribute to variability in early-appearing prosocial behavior. Moreover, potential sources of variability in social understanding were explored and examined as additional possible predictors of prosocial behavior. Using a multi-method approach with both observed and parent-report measures, 325 children aged 18 to 30 months were administered measures of social understanding (e.g. use of emotion words; self-understanding, prosocial behavior (in separate tasks measuring instrumental helping, empathic helping, and sharing, as well as parent-reported prosociality at home, temperament (fearfulness, shyness, and social fear, and parental socialization of prosocial behavior in the family. Individual differences in social understanding predicted variability in empathic helping and parent-reported prosociality, but not instrumental helping or sharing. Parental socialization of prosocial behavior was positively associated with toddlers’ social understanding, prosocial behavior at home, and instrumental helping in the lab, and negatively associated with sharing (possibly reflecting parents’ increased efforts to encourage children who were less likely to share. Further, socialization moderated the association between social understanding and prosocial behavior, such that social understanding was less predictive of prosocial behavior among children whose parents took a more active role in socializing their prosociality. None of the dimensions of temperament was associated with either social understanding or prosocial behavior. Parental socialization of prosocial behavior is thus an important source of variability in children’s early prosociality, acting in concert with early differences in social understanding, with different patterns of influence for different subtypes of prosocial behavior.

  10. Developmental Trajectories of Peer-Reported Aggressive Behavior: The Role of Friendship Understanding, Friendship Quality, and Friends’ Aggressive Behavior

    Science.gov (United States)

    Malti, Tina; McDonald, Kristina; Rubin, Kenneth H.; Rose-Krasnor, Linda; Booth-LaForce, Cathryn

    2015-01-01

    Objective To investigate developmental trajectories in peer-reported aggressive behavior across the transition from elementary-to-middle school, and whether aggressive behavior trajectories were associated with friendship quality, friends’ aggressive behavior, and the ways in which children think about their friendships. Method Participants included a community sample of 230 5th grade children who were assessed when they made a transition from elementary-to-middle school (6th grade). Peer nominations were used to assess the target child’s and friend’s aggressive behavior. Self- and friend reports were used to measure friendship quality; friendship understanding was assessed via a structured interview. Results General Growth Mixture Modeling (GGMM) revealed three distinct trajectories of peer-reported aggressive behavior across the school transition: low-stable, decreasing, and increasing. Adolescents’ understanding of friendship formation differentiated the decreasing from the low-stable aggressive behavior trajectories, and the understanding of friendship trust differentiated the increasing from the low-stable aggressive and decreasing aggressive behavior trajectories. Conclusions The findings indicated that a sophisticated understanding of friendship may serve as a protective factor for initially aggressive adolescents as they transition into middle school. Promoting a deepened understanding of friendship relations and their role in one’s own and others’ well-being may serve as an important prevention and intervention strategy to reduce aggressive behavior. PMID:26688775

  11. Developmental Trajectories of Peer-Reported Aggressive Behavior: The Role of Friendship Understanding, Friendship Quality, and Friends' Aggressive Behavior.

    Science.gov (United States)

    Malti, Tina; McDonald, Kristina; Rubin, Kenneth H; Rose-Krasnor, Linda; Booth-LaForce, Cathryn

    2015-10-01

    To investigate developmental trajectories in peer-reported aggressive behavior across the transition from elementary-to-middle school, and whether aggressive behavior trajectories were associated with friendship quality, friends' aggressive behavior, and the ways in which children think about their friendships. Participants included a community sample of 230 5 th grade children who were assessed when they made a transition from elementary-to-middle school (6 th grade). Peer nominations were used to assess the target child's and friend's aggressive behavior. Self- and friend reports were used to measure friendship quality; friendship understanding was assessed via a structured interview. General Growth Mixture Modeling (GGMM) revealed three distinct trajectories of peer-reported aggressive behavior across the school transition: low-stable, decreasing, and increasing. Adolescents' understanding of friendship formation differentiated the decreasing from the low-stable aggressive behavior trajectories, and the understanding of friendship trust differentiated the increasing from the low-stable aggressive and decreasing aggressive behavior trajectories. The findings indicated that a sophisticated understanding of friendship may serve as a protective factor for initially aggressive adolescents as they transition into middle school. Promoting a deepened understanding of friendship relations and their role in one's own and others' well-being may serve as an important prevention and intervention strategy to reduce aggressive behavior.

  12. 3D ejection behavior of different sized particles in the grain-bed collision process

    Science.gov (United States)

    Xing, Mao; He, Caiyun

    2013-04-01

    The impact-ejection process on a mixed-grain-size bed with granular packing was simulated with the discrete element method in order to understand the interaction between different sized grains in natural aeolian sand transport. In this model, the granular bed was formed by settling the randomly generated two-sized particles under gravity, and then a foreign particle was shot onto the granular bed at different speeds and angles. The recorded speed, direction and number of the ejected particles were then analyzed. It was found that the probability distributions of the ejection speed and angle for different sized particles are all identical to those for the single size grain-bed collision process, the mean ejection speeds of different sized particles are nearly equal, and the mean ejection angles of different sized particles are all equal to a constant of 60°. The average number of each size of ejected particles grows linearly with the increasing impact speed but remains invariant for various impact angles. Moreover, the smaller particles are preferentially ejected and the ratio between the mean numbers of different sized particles is independent of both the impact speed and angle. Additionally, the ejected particles were found to move in a 3D space, they become distributed symmetrically around the incident plane and jump not only forward but also backward. These results are critical to understanding the grain size-induced inhomogeneity in aeolian sand transport.

  13. The Study of Intelligent Vehicle Navigation Path Based on Behavior Coordination of Particle Swarm.

    Science.gov (United States)

    Han, Gaining; Fu, Weiping; Wang, Wen

    2016-01-01

    In the behavior dynamics model, behavior competition leads to the shock problem of the intelligent vehicle navigation path, because of the simultaneous occurrence of the time-variant target behavior and obstacle avoidance behavior. Considering the safety and real-time of intelligent vehicle, the particle swarm optimization (PSO) algorithm is proposed to solve these problems for the optimization of weight coefficients of the heading angle and the path velocity. Firstly, according to the behavior dynamics model, the fitness function is defined concerning the intelligent vehicle driving characteristics, the distance between intelligent vehicle and obstacle, and distance of intelligent vehicle and target. Secondly, behavior coordination parameters that minimize the fitness function are obtained by particle swarm optimization algorithms. Finally, the simulation results show that the optimization method and its fitness function can improve the perturbations of the vehicle planning path and real-time and reliability.

  14. Using the Theory of Planned Behavior to Understand the Beliefs of Chinese Teachers Concerning Teaching Games for Understanding

    Science.gov (United States)

    Wang, Lijuan

    2013-01-01

    This study describes the beliefs of Physical Education (PE) teachers regarding Teaching Games for Understanding (TGfU) based on the Theory of Planned Behavior (TPB). Twenty PE teachers participated in this study. Data collection consisted of a survey on demographic data and semistructured interviews. The research results indicate that the teachers…

  15. Understanding criminal behavior: Empathic impairment in criminal offenders.

    Science.gov (United States)

    Mariano, Melania; Pino, Maria Chiara; Peretti, Sara; Valenti, Marco; Mazza, Monica

    2017-08-01

    Criminal offenders (CO) are characterized by antisocial and impulsive lifestyles and reduced empathy competence. According to Zaki and Ochsner, empathy is a process that can be divided into three components: mentalizing, emotional sharing and prosocial concern. The aim of our study was to evaluate these competences in 74 criminal subjects compared to 65 controls. The CO group demonstrated a lower ability in measures of mentalizing and sharing, especially in recognizing the mental and emotional states of other people by observing their eyes and sharing other people's emotions. Conversely, CO subjects showed better abilities in prosocial concern measures, such as judging and predicting the emotions and behavior of other people, but they were not able to evaluate the gravity of violations of social rules as well as the control group. In addition, logistic regression results show that the higher the deficits in the mentalizing component are, the higher the probability of committing a crime against another person. Taken together, our results suggest that criminal subjects are able to judge and recognize other people's behavior as right or wrong in a social context, but they are not able to recognize and share the suffering of other people.

  16. Understanding prehospital delay behavior in acute myocardial infarction in women.

    Science.gov (United States)

    Waller, Cynthia G

    2006-12-01

    Studies demonstrate that acute myocardial infarction (AMI) mortality can be reduced if reperfusion therapy is initiated within 1 hour of AMI symptom onset. However, a considerable number of men and women arrive at the emergency department outside of the time frame for thrombolytic and angioplasty effectiveness. This is especially true for women who have been shown to delay longer than men due to their prehospital decision-making process utilized. With a mean total delay time greater than 4 hours, the time interval from symptom onset to transport activation to the hospital consumes the majority of the prehospital phase of emergency cardiac care. The health belief model, self-regulation model, theory of reasoned action, and theory of planned behavior have all been used to describe the prehospital decision-making process of both men and women with an AMI and the variables that impact that process. These models have identified the importance of symptom attribution to cardiac-related causes as a target variable for research and interventions related to care-seeking behavior.

  17. Applying the reasoned action approach to understanding health protection and health risk behaviors.

    Science.gov (United States)

    Conner, Mark; McEachan, Rosemary; Lawton, Rebecca; Gardner, Peter

    2017-12-01

    The Reasoned Action Approach (RAA) developed out of the Theory of Reasoned Action and Theory of Planned Behavior but has not yet been widely applied to understanding health behaviors. The present research employed the RAA in a prospective design to test predictions of intention and action for groups of protection and risk behaviors separately in the same sample. To test the RAA for health protection and risk behaviors. Measures of RAA components plus past behavior were taken in relation to eight protection and six risk behaviors in 385 adults. Self-reported behavior was assessed one month later. Multi-level modelling showed instrumental attitude, experiential attitude, descriptive norms, capacity and past behavior were significant positive predictors of intentions to engage in protection or risk behaviors. Injunctive norms were only significant predictors of intention in protection behaviors. Autonomy was a significant positive predictor of intentions in protection behaviors and a negative predictor in risk behaviors (the latter relationship became non-significant when controlling for past behavior). Multi-level modelling showed that intention, capacity, and past behavior were significant positive predictors of action for both protection and risk behaviors. Experiential attitude and descriptive norm were additional significant positive predictors of risk behaviors. The RAA has utility in predicting both protection and risk health behaviors although the power of predictors may vary across these types of health behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Deformation Behavior of Sub-micron and Micron Sized Alumina Particles in Compression.

    Energy Technology Data Exchange (ETDEWEB)

    Sarobol, Pylin; Chandross, Michael E.; Carroll, Jay; Mook, William; Boyce, Brad; Kotula, Paul Gabriel; McKenzie, Bonnie Beth; Bufford, Daniel Charles; Hall, Aaron Christopher.

    2014-09-01

    The ability to integrate ceramics with other materials has been limited due to high temperature (>800degC) ceramic processing. Recently, researchers demonstrated a novel process , aerosol deposition (AD), to fabricate ceramic films at room temperature (RT). In this process, sub - micro n sized ceramic particles are accelerated by pressurized gas, impacted on the substrate, plastically deformed, and form a dense film under vacuum. This AD process eliminates high temperature processing thereby enabling new coatings and device integration, in which ceramics can be deposited on metals, plastics, and glass. However, k nowledge in fundamental mechanisms for ceramic particle s to deform and form a dense ceramic film is still needed and is essential in advancing this novel RT technology. In this wo rk, a combination of experimentation and atomistic simulation was used to determine the deformation behavior of sub - micron sized ceramic particle s ; this is the first fundamental step needed to explain coating formation in the AD process . High purity, singl e crystal, alpha alumina particles with nominal size s of 0.3 um and 3.0 um were examined. Particle characterization, using transmission electron microscopy (TEM ), showed that the 0.3 u m particles were relatively defect - free single crystals whereas 3.0 u m p articles were highly defective single crystals or particles contained low angle grain boundaries. Sub - micron sized Al 2 O 3 particles exhibited ductile failure in compression. In situ compression experiments showed 0.3um particles deformed plastically, fractured, and became polycrystalline. Moreover, dislocation activit y was observed within the se particles during compression . These sub - micron sized Al 2 O 3 particles exhibited large accum ulated strain (2 - 3 times those of micron - sized particles) before first fracture. I n agreement with the findings from experimentation , a tomistic simulation s of nano - Al 2 O 3 particles showed dislocation slip and

  19. Particle Engineering of Excipients for Direct Compression: Understanding the Role of Material Properties.

    Science.gov (United States)

    Mangal, Sharad; Meiser, Felix; Morton, David; Larson, Ian

    2015-01-01

    Tablets represent the preferred and most commonly dispensed pharmaceutical dosage form for administering active pharmaceutical ingredients (APIs). Minimizing the cost of goods and improving manufacturing output efficiency has motivated companies to use direct compression as a preferred method of tablet manufacturing. Excipients dictate the success of direct compression, notably by optimizing powder formulation compactability and flow, thus there has been a surge in creating excipients specifically designed to meet these needs for direct compression. Greater scientific understanding of tablet manufacturing coupled with effective application of the principles of material science and particle engineering has resulted in a number of improved direct compression excipients. Despite this, significant practical disadvantages of direct compression remain relative to granulation, and this is partly due to the limitations of direct compression excipients. For instance, in formulating high-dose APIs, a much higher level of excipient is required relative to wet or dry granulation and so tablets are much bigger. Creating excipients to enable direct compression of high-dose APIs requires the knowledge of the relationship between fundamental material properties and excipient functionalities. In this paper, we review the current understanding of the relationship between fundamental material properties and excipient functionality for direct compression.

  20. Understanding the Relationship Between Subjective Wellbeing and Gambling Behavior.

    Science.gov (United States)

    Farrell, Lisa

    2018-03-01

    This paper examines the relationship between gambling behavior and subjective wellbeing. It is often asserted that populations consist of different types of gamblers: those for whom gambling is a harmless leisure activity and those (pathological/problem gamblers) for whom the activity has harmful effects. One might, therefore, assume that subjective wellbeing will be negativity associated with an individual's level of gambling addiction. Alternatively, gamblers may choose to gamble because they derive utility from participating in this activity and so the relationship between happiness and gambling might be positively correlated. In this paper we test this association, empirically, using data from the 2010 British Gambling Prevalence Survey. The statistically significant findings from this analysis support the hypothesis that individual wellbeing falls as gambling disorder increases.

  1. Students’ online purchasing behavior in Malaysia: Understanding online shopping attitude

    Directory of Open Access Journals (Sweden)

    Marzieh Zendehdel

    2015-12-01

    Full Text Available Studies examining the factors that affect the online purchasing behavior of consumers are rare, despite the prospective advance of e-commerce in Malaysia. The present study examines particular factors that influence the attitude of potential consumers to purchase online by using the attributes from the diffusion of innovations theory of Rogers, the attribute of perception of risk, and the subjective norms toward online purchasing. Consumers’ perceived risks of online shopping have become a vital subject in research because they directly influence users’ attitude toward online purchasing. The structural equation modeling method was used to analyze the data gathered on students using e-commerce, and, thus, to validate the model. According to the results, consumers’ attitude toward online purchasing affects the intention toward online purchasing. The other influential factors are compatibility, relative advantage, and subjective norm.

  2. Understanding change in recycling and littering behavior across a school social network.

    Science.gov (United States)

    Long, Jennifer; Harré, Niki; Atkinson, Quentin D

    2014-06-01

    Understanding how communities change requires examining how individuals' beliefs and behaviors are shaped by those around them. This paper investigates behavior change across a large social network following a recycling intervention in a New Zealand high school community. We used a mixed methods design, combining focus group data with social network analysis from two waves of a questionnaire that measured friendship networks; recycling and littering behaviors; perceived behavioral norms; and teacher, friend, and parent encouragement for these behaviors. Recycling behavior increased significantly over the course of our study. Supporting the importance of social networks in this context, both littering and recycling behavior showed clear social clustering. Further, the degree of change in an individuals' littering and recycling behavior across time was predicted by friends' prior behavior. Focus group data provided insight into students' perceptions of social interactions and how these contributed to littering and recycling behavior.

  3. Investigation into the morphology, composition, structure and dry tribological behavior of rice husk ceramic particles

    Science.gov (United States)

    Hu, Enzhu; Hu, Kunhong; Xu, Zeyin; Hu, Xianguo; Dearn, Karl David; Xu, Yong; Xu, Yufu; Xu, Le

    2016-03-01

    To expand the application of rice husk (RH) resource, this study developed carbon-based RH ceramic (RHC) particles using a common high-temperature carbonization method. The morphology, composition, and structure of the RHC particles were characterized with a series of modern analysis technologies and were then compared with those of the initial RH powder and carbonized RH (CRH) particles. The dry tribological behavior of RHC particle adobes (RHAs) was also investigated. Results showed the sheet-shaped morphology of the RHC particles. The graphitization degree of the RHC particles was lower than that of the CRH particles possibly because the phenolic resin (PR) filled the micro-pores of the RH particles, thereby prompting the formation of amorphous carbon in the RHC particles as a result of high-temperature carbonization. The appearance of a hydroxy function group (sbnd OH) on the surface of the RHC particles was ascribed to the decomposition of PR at 900 °C. The friction coefficients and mass loss rates of the RHAs almost increased with the rise in load and velocity. In addition, the friction coefficients of the RHAs decreased at high load (5 N) and velocity (0.261 m/s) conditions. Such outcome indicated that the variation of contact area between steel ball and RHA at high load and velocity conditions resulted in the abrasive wear or catastrophic wear.

  4. Thermal behavior of aerosol particles from biomass burning during the BBOP campaign using transmission electron microscopy

    Science.gov (United States)

    Adachi, K.; Ishimoto, H.; Sedlacek, A. J., III; Kleinman, L. I.; Chand, D.; Hubbe, J. M.; Buseck, P. R.

    2017-12-01

    Aerosol samples were collected from wildland and agricultural biomass fires in North America during the 2013 Biomass Burning Observation Project (BBOP). We show in-situ shape and size changes and variations in the compositions of individual particles before and after heating using a transmission electron microscope (TEM). The responses of aerosol particles to heating are important for measurements of their chemical, physical, and optical properties, classification, and determination of origin. However, the thermal behavior of organic aerosol particles is largely unknown. We provide a method to analyze such thermal behavior through heating from room temperature to >600°C by using a heating holder within TEM. The results indicate that individual tar balls (TB; spherical organic material) from biomass burning retained, on average, up to 30% of their volume when heated to 600°C. Chemical analysis reveals that K and Na remained in the residues, whereas S and O were lost. In contrast to bulk sample measurements of carbonaceous particles using thermal/optical carbon analyzers, our single-particle results imply that many individual organic particles consist of multiple types of organic matter having different thermal stabilities. Our results also suggest that because of their thermal stability, some organic particles may not be detectable by using aerosol mass spectrometry or thermal/optical carbon analyzers. This result can lead to an underestimate of the abundance of TBs and other organic particles, and therefore biomass burning may have a greater influence than is currently recognized in regional and global climate models.

  5. Understanding externalizing behavior from children's personality and parenting characteristics.

    Science.gov (United States)

    Hiramura, Hidetoshi; Uji, Masayo; Shikai, Noriko; Chen, Zi; Matsuoka, Nao; Kitamura, Toshinori

    2010-01-30

    A total of 946 Japanese children in the 5th to 9th grades and their parents were studied in order to investigate the extent to which parenting characteristics (measured by the Parental Bonding Instrument) and the personality of the child (measured by the junior version of the Temperament and Character Inventory) would be associated with the two aspects of the externalizing problems--aggression and delinquency--of the child (measured by the Child Behavior Checklist). A series of regression analyses demonstrated that (1) aggressive children were higher in Novelty Seeking, and delinquent children were higher in Novelty Seeking and lower in Harm Avoidance, and (2) both aggressive and delinquent children were characterised by low maternal care, paternal over-protection, and low maternal overprotection. A structural equation model confirmed these findings except for the link between the two externalizing behaviour scores and the maternal care. Moreover, it was suggested that Novelty seeking of the child would be predicted by low parental care and low paternal and high maternal overprotection. The children's aggression and delinquency could, to some extent, be explainable by their temperament patterns and parental characteristics.

  6. Applying theory-driven approaches to understanding and modifying clinicians' behavior: what do we know?

    Science.gov (United States)

    Perkins, Matthew B; Jensen, Peter S; Jaccard, James; Gollwitzer, Peter; Oettingen, Gabriele; Pappadopulos, Elizabeth; Hoagwood, Kimberly E

    2007-03-01

    Despite major recent research advances, large gaps exist between accepted mental health knowledge and clinicians' real-world practices. Although hundreds of studies have successfully utilized basic behavioral science theories to understand, predict, and change patients' health behaviors, the extent to which these theories-most notably the theory of reasoned action (TRA) and its extension, the theory of planned behavior (TPB)-have been applied to understand and change clinician behavior is unclear. This article reviews the application of theory-driven approaches to understanding and changing clinician behaviors. MEDLINE and PsycINFO databases were searched, along with bibliographies, textbooks on health behavior or public health, and references from experts, to find article titles that describe theory-driven approaches (TRA or TPB) to understanding and modifying health professionals' behavior. A total of 19 articles that detailed 20 studies described the use of TRA or TPB and clinicians' behavior. Eight articles describe the use of TRA or TPB with physicians, four relate to nurses, three relate to pharmacists, and two relate to health workers. Only two articles applied TRA or TPB to mental health clinicians. The body of work shows that different constructs of TRA or TPB predict intentions and behavior among different groups of clinicians and for different behaviors and guidelines. The number of studies on this topic is extremely limited, but they offer a rationale and a direction for future research as well as a theoretical basis for increasing the specificity and efficiency of clinician-targeted interventions.

  7. Applied behavior analysis: understanding and changing behavior in the community-a representative review.

    Science.gov (United States)

    Luyben, Paul D

    2009-01-01

    Applied behavior analysis, a psychological discipline, has been characterized as the science of behavior change (Chance, 2006). Research in applied behavior analysis has been published for approximately 40 years since the initial publication of the Journal of Applied Behavior Analysis in 1968. The field now encompasses a wide range of human behavior. Although much of the published research centers on problem behaviors that occur in schools and among people with disabilities, a substantial body of knowledge has emerged in community settings. This article provides a review of the behavioral community research published in the Journal of Applied Behavior Analysis as representative of this work, including research in the areas of home and family, health, safety, community involvement and the environment, recreation and sports, crime and delinquency, and organizations. In the interest of space, research in schools and with people with disabilities has been excluded from this review.

  8. Understanding the behavior of buried Bi nanostructures from first principles

    Science.gov (United States)

    Sims, Hunter; Pantelides, Sokrates; Song, Jiaming; Hudak, Bethany; Lupini, Andrew; Snijders, Paul

    Bismuth dopants in silicon provide several advantages over other n-type options such as phosphorus for usage as quantum bits (qubits). Self-assembled Bi nanolines on Si (100) surfaces may provide a means of introducing these dopants with greater control over placement and with less damage to the host system than is possible using ion implantation. However, these structures have thus far only been observed in vacuum, limiting their usefulness for application. We examine Bi nanolines overgrown with amorphous Si using density functional theory, comparing our findings with observations from scanning tunneling microscopy (STM) and atomic-resolution scanning transmission electron microscopy (STEM) in order to better understand the way in which the Si surface is influenced by both the Bi ad-dimers and the capping layer. We compare the thermodynamic stability of the generally accepted haiku defect core to the modified core that we observe and offer insight from total energy calculations into how the overgrowth process affects the nanolines. Supported by Department of Energy Grant DE-FG02- 09ER46554 (VU) and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy (ORNL).

  9. Dynamic behavior of a solid particle bed in a liquid pool

    International Nuclear Information System (INIS)

    Liu Ping; Yasunaka, Satoshi; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji; Yamano, Hidemasa; Tobita, Yoshiharu

    2007-01-01

    Dynamic behavior of solid particle beds in a liquid pool against pressure transients was investigated to model the mobility of core materials in a postulated disrupted core of a liquid metal fast reactor. A series of experiments was performed with a particle bed of different bed heights, comprising different monotype solid particles, where variable initial pressures of the originally pressurized nitrogen gas were adopted as the pressure sources. Computational simulations of the experiments were performed using SIMMER-III, a fast reactor safety analysis code. Comparisons between simulated and experimental results show that the physical model for multiphase flows used in the SIMMER-III code can reasonably represent the transient behaviors of pool multiphase flows with rich solid phases, as observed in the current experiments. This demonstrates the basic validity of the SIMMER-III code on simulating the dynamic behaviors induced by pressure transients in a low-energy disrupted core of a liquid metal fast reactor with rich solid phases

  10. Behavior of ceramic particles at the solid-liquid metal interface in metal matrix composites

    Science.gov (United States)

    Stefanescu, D. M.; Dhindaw, B. K.; Kacar, S. A.; Moitra, A.

    1988-01-01

    Directional solidification results were obtained in order to investigate particle behavior at the solid-liquid interface in Al-2 pct Mg (cellular interface) and Al-6.1 pct Ni (eutectic interface) alloys. It is found that particles can be entrapped in the solid if adequate solidification rates and temperature gradients are used. Model results showed critical velocity values slightly higher than those obtained experimentally.

  11. Influence of particle-phase state on the hygroscopic behavior of mixed organic-inorganic aerosols

    OpenAIRE

    Hodas, N.; Zuend, A.; Mui, W.; Flagan, R. C.; Seinfeld, J. H.

    2015-01-01

    Recent work has demonstrated that organic and mixed organic–inorganic particles can exhibit multiple phase states depending on their chemical composition and on ambient conditions such as relative humidity (RH). To explore the extent to which water uptake varies with particle phase behavior, hygroscopic growth factors (HGFs) of nine laboratory-generated, organic and organic–inorganic aerosol systems with physical states ranging from well-mixed liquids, to phase-separa...

  12. The grain refinement behavior of TiB2 particles prepared with in situ technology

    International Nuclear Information System (INIS)

    Wang Chunlei; Wang Mingxing; Yu Benhai; Chen Dong; Qin Ping; Feng Minghai; Dai Qirun

    2007-01-01

    The grain-refining behavior of TiB 2 particles was investigated by the method of adding Al-4B master alloy into the melt of electrolytic low-titanium aluminum (ELTA). The results indicate that TiB 2 particles will be formed when the Al-4B master alloy is added into the melt of ELTA. These TiB 2 particles are produced by in situ technology, thus their surface properties are preserved and do not alter. At the bottom of the melt, the TiB 2 particles are pushed to the grain boundaries because of the absence of enough titanium atoms, which indicates that TiB 2 particles alone are not potent nuclei of α-Al. Though some TiB 2 particles settle down at the bottom, there are still numbers of fine TiB 2 particles suspended. These TiB 2 particles, together with the titanium atoms left, will form much more heterogeneous nucleation sites during the solidification of the melt, resulting in the grain-refining efficiency of the ELTA with Al-4B addition being improved obviously. To investigate the grain-refining mechanism of aluminum, this method has its advantages in comparison with that of adding synthetic TiB 2 particles into the melt of aluminum

  13. Deliquescence and efflorescence behavior of ternary inorganic/organic/water aerosol particles.

    Science.gov (United States)

    Peckhaus, Andreas; Grass, Stefan; Treuel, Lennart; Zellner, Reinhard

    2012-06-21

    The deliquescence behavior of ternary inorganic (ammonium sulfate and ammonium nitrate)/organic (glutaric acid and malonic acid)/water aerosol particles has been investigated at 293 K using a novel surface aerosol microscopy (SAM) technique. The results obtained for the deliquescence relative humidities (DRH) for particles of variable inorganic/organic contents show a eutectic behavior with the mixed particles showing deliquescence at lower DRH compared to the pure inorganic and organic components, respectively. This behavior has been quantitatively modeled using the extended aerosol inorganics (E-AIM) thermodynamic model of Clegg et al. in combination with the UNIFAC group activity approach to account for organic molecular solutes. In addition, we have investigated the crystallization behavior of supersatured and formerly deliquesced ternary solution droplets using space resolved Raman spectroscopy. It is found that such droplets produce solid particles in which the inorganic and organic phases show some spatial separation with the organic component being predominantly found at the outer part of the particle. Independent measurements of the contact angles of such ternary droplets reveal that their angles are within experimental error identical to those of the purely organic/water solutions.

  14. Influence of Janus particle shape on their interfacial behavior at liquid-liquid interfaces.

    Science.gov (United States)

    Ruhland, Thomas M; Gröschel, André H; Ballard, Nicholas; Skelhon, Thomas S; Walther, Andreas; Müller, Axel H E; Bon, Stefan A F

    2013-02-05

    We investigate the self-assembly behavior of Janus particles with different geometries at a liquid-liquid interface. The Janus particles we focus on are characterized by a phase separation along their major axis into two hemicylinders of different wettability. We present a combination of experimental and simulation data together with detailed studies elucidating the mechanisms governing the adsorption process of Janus spheres, Janus cylinders, and Janus discs. Using the pendant drop technique, we monitor the assembly kinetics following changes in the interfacial tension of nanoparticle adsorption. According to the evolution of the interfacial tension and simulation data, we will specify the characteristics of early to late stages of the Janus particle adsorption and discuss the effect of Janus particle shape and geometry. The adsorption is characterized by three adsorption stages which are based on the different assembly kinetics and different adsorption mechanisms depending on the particle shape.

  15. Understanding the mechanisms of sickle cell disease by simulations with a discrete particle model

    Science.gov (United States)

    Hui, Katrina; Lin, Guang; Pan, Wenxiao

    2013-01-01

    Sickle cell disease (SCD) is an inherited blood disorder characterized by rigid, sickle-shaped red blood cells (RBCs). Because of their rigidity and shape, sickle cells can get stuck in smaller blood vessels, causing blockages and depriving oxygen to tissues. This study develops and applies mathematical models to better understand the mechanism of SCD. Two-dimensional models of RBCs and blood vessels have been constructed by representing them as discrete particles interacting with different forces. The nonlinear, elastic property of healthy RBCs could be adequately reproduced using a cosine angle bending force and a worm-like chain spring force. With the ability to deform, RBCs can squeeze through narrow blood vessels. In modeling sickle cells as rigid bodies and applying repelling and friction forces from the blood vessel, this study shows that geometrical factors (dimensions of the sickle cell and blood vessels) as well as rigidity and adhesiveness of the sickle cell all play an important role in determining how, and if, sickle cells become trapped within narrow blood capillaries. With lack of data to validate the model, this study primarily provides a sensitivity analysis of factors influencing sickle cell occlusion and identified critical data to support future modeling.

  16. WALL-FOLLOWING BEHAVIOR-BASED MOBILE ROBOT USING PARTICLE SWARM FUZZY CONTROLLER

    Directory of Open Access Journals (Sweden)

    Andi Adriansyah

    2016-02-01

    Full Text Available Behavior-based control architecture has been broadly recognized due to their compentence in mobile robot development. Fuzzy logic system characteristics are appropriate to address the behavior design problems. Nevertheless, there are problems encountered when setting fuzzy variables manually. Consequently, most of the efforts in the field, produce certain works for the study of fuzzy systems with added learning abilities. This paper presents the improvement of fuzzy behavior-based control architecture using Particle Swarm Optimization (PSO. A wall-following behaviors used on Particle Swarm Fuzzy Controller (PSFC are developed using the modified PSO with two stages of the PSFC process. Several simulations have been accomplished to analyze the algorithm. The promising performance have proved that the proposed control architecture for mobile robot has better capability to accomplish useful task in real office-like environment.

  17. Towards an understanding of the role of the environment in the development of early callous behavior

    Science.gov (United States)

    Waller, Rebecca; Shaw, Daniel S.; Neiderhiser, Jenae M.; Ganiban, Jody M.; Natsuaki, Misaki N.; Reiss, David; Trentacosta, Christopher; Leve, Leslie D.; Hyde, Luke W.

    2015-01-01

    Key to understanding the long-term impact of social inequalities is identifying early behaviors that may signal higher risk for later poor psychosocial outcomes, such as psychopathology. A set of early-emerging characteristics that may signal risk for later externalizing psychopathology is Callous-Unemotional (CU) behavior. CU behavior predict severe and chronic trajectories of externalizing behaviors in youth. However, much research on CU behavior has focused on late childhood and adolescence, with little attention paid to early childhood when preventative interventions may be most effective. In this paper, we summarize our recent work showing that: (1) CU behavior can be identified in early childhood using items from common behavior checklists; (2) CU behavior predicts worse outcomes across early childhood; (3) CU behavior exhibits a distinct nomological network from other early externalizing behaviors; and (4) malleable environmental factors, particularly parenting, may play a role in the development of early CU behaviors. We discuss the challenges of studying contextual contributors to the development of CU behavior in terms of gene-environment correlations and present initial results from work examining CU behavior in an adoption study in which gene-environment correlations are examined in early childhood. We find that parenting is a predictor of early CU behavior even in a sample in which parents are not genetically related to the children. PMID:26291075

  18. Using the Theory of Planned Behavior to Understand Cervical Cancer Screening among Latinas

    Science.gov (United States)

    Roncancio, Angelica M.; Ward, Kristy K.; Sanchez, Ingrid A.; Cano, Miguel A.; Byrd, Theresa L.; Vernon, Sally W.; Fernandez-Esquer, Maria Eugenia; Fernandez, Maria E.

    2015-01-01

    To reduce the high incidence of cervical cancer among Latinas in the United States it is important to understand factors that predict screening behavior. The aim of this study was to test the utility of theory of planned behavior in predicting cervical cancer screening among a group of Latinas. A sample of Latinas (N = 614) completed a baseline…

  19. Maternal Behavior Modifications during Pretense and Their Long-Term Effects on Toddlers' Understanding of Pretense

    Science.gov (United States)

    Nakamichi, Naoko

    2015-01-01

    Recent studies indicate the need to investigate the sources of toddlers' understanding of another person's pretense. The present study is a cultural and longitudinal extension of the work of Lillard and Witherington (2004), who claimed that mothers modify their behaviors during pretense and that the some of these behavior modifications help their…

  20. Understanding Nature-Related Behaviors among Children through a Theory of Reasoned Action Approach

    Science.gov (United States)

    Gotch, Chad; Hall, Troy

    2004-01-01

    The Theory of Reasoned Action has proven to be a valuable tool for predicting and understanding behavior and, as such, provides a potentially important basis for environmental education program design. This study used a Theory of Reasoned Action approach to examine a unique type of behavior (nature-related activities) and a unique population…

  1. Soil particle tracing using RFID tags for elucidating the behavior of radiocesium on bare soil surfaces in Fukushima

    Science.gov (United States)

    Manome, Ryo; Onda, Yuichi; Patin, Jeremy; Stefani, Chiara; Yoshimura, Kazuya; Parsons, Tony; Cooper, James

    2014-05-01

    Radioactive materials are generally associated with soil particles in terrestrial environment and therefore the better understanding soil erosion processes is expected to improve the mitigation of radioactive risks. Spatial variability in soil erosion has been one of critical issues for soil erosion management. This study attempts to track soil particle movement on soil surfaces by employing Radio Frequency Identification (RFID) tags for the better understanding radiocesium behavior. A RFID tag contains a specific electronically identifier and it permits tracing its movement by reading the identifier. In this study, we made artificial soil particles by coating the RFID tags with cement material. The particle diameters of the artificial soil particles approximately ranged from 3 to 5 mm. The artificial soil particles were distributed in a reticular pattern on a soil erosion plot (bare soil surface, 22.13 m length × 5 m width, 4.4° slope) in Kawamata town where radiocesium deposited because of the Fukushima Dai-ichi power plant accident. After their distribution on October 2012, we had read the identifiers of RFID tags and recorded their locations on the plot for 14 times by September 2013. Moving distance (MD) was calculated based on the difference of the location for each sampling date. The topographical changes on the plot were also monitored with a laser scanner to describe interrill erosion and rill erosion area on 11occasions. Median MD is 10.8cm for all the observations. Median MD on interrill and rill erosion areas were 9.8 cm and 20.7 cm, respectively. Seasonal variation in MD was observed; an extremely large MD was found in May 2013, at the first reading after the winter season. This large MD after winter suggests that snowmelt runoff was the dominant process which transported the soil particles. Comparing the MD with the observed amounts of rainfall, sediment and runoff on the plot, significant positive correlation were found if the data of May, 2013

  2. Investigating flow behaviors of colloidal materials at the single-particle scale

    Science.gov (United States)

    Lin, Yen-Chih

    My thesis work focuses on the nonlinear mechanical behaviors of colloidal suspensions at the particle-level. This work covers both quiescent and strongly sheared suspensions. For quiescent suspensions, we image their 3D structures with confocal microscopy, and implement Stress Assessment from Local Structural Anisotropy (SALSA) to visualize the stress fields in them. Unlike traditional numerical methods, SALSA takes a statistical approach converting the probability of hard-sphere Brownian collisions to stresses. This direct stress measurement allows us to quantify the particle-level stresses surrounding vacancies, dislocations, and grain boundaries in crystalline materials. To drive the suspensions away from equilibrium, we develop a confocal-rheoscope, which is able to shear and image colloidal materials simultaneously. Using this device, we investigate the nonlinear flow behavior governed by Brownian motion, shear induced diffusion, and advection, and more importantly, disentangle them. We also study particle assembly and its corresponding rheological properties under confinement. Finally, we study even more strongly sheared suspensions, in which particle dynamics are too fast to be imaged by a confocal microscope. Here, we use flow reversal rheometry to reveal the underlying mechanism of suspension shear thickening where the viscosity increases with shear rate. We show that the thickening behavior of a suspension arises from the particle contact forces rather than hydrodynamic interactions. Such findings then lead us to design a biaxial shear protocol that can tune the suspension viscosity on demand. This viscosity tuning capability is a foundational step toward using dense suspensions in 3D printing, energy storage, and robotics.

  3. The adsorption behavior between particle contamination and fused silica in high-energy laser system

    Science.gov (United States)

    Bai, Q. S.; He, X.; Zhang, K.; Yang, W.; Zhang, F. H.; Yuan, X. D.

    2017-08-01

    In high-energy laser facility, the residual nano-particles that are remained in mechanical system or produced by the interaction of kinetic-pairs are inevitable. The generation and the propagation of particulate pollutants will seriously reduce the performance of the laser systems. Therefore, the research about the adsorption behavior of particle contaminants on fused silica is very important to maintain the optical components' surface clean, reduce induced damage, and finally prolong the life of the optical components. In this paper, the adsorption behavior between aluminum nano-particles and fused silica was simulated by molecular dynamics method. The effect of the surface roughness of fused silica on the state of adsorption and the state before adsorption has been studied. Then an experiment system based on an atomic force microscope was established to measure the adsorption force and further to verify the simulated results. Finally, the adsorption mechanism between metallic nano-particles and fused silica was revealed. The results show that surface roughness and the size of the particles are two of the main factors to influence the adsorption force. The rough fused silica surface can be "particle-phobic" due to the decreased contact area, which is beneficial to keep the fused silica surface clean.

  4. Specific surface area behavior of a dissolving population of particles. Augmenting Mercer Dissolution Theory

    International Nuclear Information System (INIS)

    Scripsick, R.C.; Rothenberg, S.J.

    1986-01-01

    Specific surface area (Sp) measurements were made on two uranium oxide aerosol materials before and after in vitro dissolution studies were performed on the materials. The results of these Sp measurements were evaluated relative to predictions made from extending Mercer dissolution theory to describe the Sp behavior of a dissolving population of particles

  5. Biased motion of a brownian particle for the pausing time behavior of the CTRW

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.S. (National Fisheries Univ., Busan (Republic of Korea))

    1982-12-01

    The purpose of this paper is to discuss the biased Brownian motion with the absorbing barrier for the pausing time behavior of the CTRW (continuous-time random walk method), regarding a Brownian particle as a walker. For two pausing time density functions, the respective values for the transport averaged velocity and the dispersion are calculated as the time t becomes large.

  6. Towards a better understanding of consumer behavior : Marginal Utility as a parameter in Neuromarketing research

    NARCIS (Netherlands)

    Alvino, Letizia; Constantinides, Efthymios; Franco, Massimo

    2017-01-01

    Understanding consumers’ decision-making process is a recurrent goal in Marketing. However, the traditional tools used in marketing, such as surveys, personal interviews and participant observations are often inadequate to analyze and understand human behavior. Since consumer decisions are often

  7. Acid Hydrolysis and Molecular Density of Phytoglycogen and Liver Glycogen Helps Understand the Bonding in Glycogen α (Composite) Particles

    Science.gov (United States)

    Powell, Prudence O.; Sullivan, Mitchell A.; Sheehy, Joshua J.; Schulz, Benjamin L.; Warren, Frederick J.; Gilbert, Robert G.

    2015-01-01

    Phytoglycogen (from certain mutant plants) and animal glycogen are highly branched glucose polymers with similarities in structural features and molecular size range. Both appear to form composite α particles from smaller β particles. The molecular size distribution of liver glycogen is bimodal, with distinct α and β components, while that of phytoglycogen is monomodal. This study aims to enhance our understanding of the nature of the link between liver-glycogen β particles resulting in the formation of large α particles. It examines the time evolution of the size distribution of these molecules during acid hydrolysis, and the size dependence of the molecular density of both glucans. The monomodal distribution of phytoglycogen decreases uniformly in time with hydrolysis, while with glycogen, the large particles degrade significantly more quickly. The size dependence of the molecular density shows qualitatively different shapes for these two types of molecules. The data, combined with a quantitative model for the evolution of the distribution during degradation, suggest that the bonding between β into α particles is different between phytoglycogen and liver glycogen, with the formation of a glycosidic linkage for phytoglycogen and a covalent or strong non-covalent linkage, most probably involving a protein, for glycogen as most likely. This finding is of importance for diabetes, where α-particle structure is impaired. PMID:25799321

  8. Acid hydrolysis and molecular density of phytoglycogen and liver glycogen helps understand the bonding in glycogen α (composite particles.

    Directory of Open Access Journals (Sweden)

    Prudence O Powell

    Full Text Available Phytoglycogen (from certain mutant plants and animal glycogen are highly branched glucose polymers with similarities in structural features and molecular size range. Both appear to form composite α particles from smaller β particles. The molecular size distribution of liver glycogen is bimodal, with distinct α and β components, while that of phytoglycogen is monomodal. This study aims to enhance our understanding of the nature of the link between liver-glycogen β particles resulting in the formation of large α particles. It examines the time evolution of the size distribution of these molecules during acid hydrolysis, and the size dependence of the molecular density of both glucans. The monomodal distribution of phytoglycogen decreases uniformly in time with hydrolysis, while with glycogen, the large particles degrade significantly more quickly. The size dependence of the molecular density shows qualitatively different shapes for these two types of molecules. The data, combined with a quantitative model for the evolution of the distribution during degradation, suggest that the bonding between β into α particles is different between phytoglycogen and liver glycogen, with the formation of a glycosidic linkage for phytoglycogen and a covalent or strong non-covalent linkage, most probably involving a protein, for glycogen as most likely. This finding is of importance for diabetes, where α-particle structure is impaired.

  9. Understanding Attitudes and Pro-Environmental Behaviors in a Chilean Community

    Directory of Open Access Journals (Sweden)

    Nicolás C. Bronfman

    2015-10-01

    Full Text Available Environmental protection and restoration are some of the major challenges faced by our society. To address this problem, it is fundamental to understand pro-environmental behaviors in the population, as well as the factors that determine them. There are, however, very few studies conducted in Latin America that are focused in understanding the environmental behavior of its citizens. The main goal of this research was to study the environmental behaviors of a Chilean community and identify the factors that determine them. To that end, a diverse set of environmental behaviors (power and water conservation, environmentally-aware consumer behavior, biodiversity protection, rational automobile use and ecological waste management and sociodemographic and attitudinal factors—based on the VBN model—were evaluated. Survey data was obtained from a statistically representative sample (N = 1537 in Santiago, Chile. Our results suggest that several participants displayed tendencies that favor more responsible environmental behaviors, with high environmental concern, and demonstrating their ample awareness of the consequences of failing to protect the environment. Nevertheless, the highest average scores of environmental behavior were related to low cost behaviors and those that imposed the fewest behavioral restrictions. In global terms, we concluded that the youngest subjects in the lowest socioeconomic group obtained the lowest scores across the pro-environmental behavior spectrum.

  10. Influence of Particle Morphology on 3D Kinematic Behavior and Strain Localization of Sheared Sand

    Energy Technology Data Exchange (ETDEWEB)

    Alshibli, Khalid A.; Jarrar, Maha F.; Druckrey, Andrew M.; Al-Raoush, Riyadh I.

    2017-02-01

    The constitutive behavior of sheared sand is highly influenced by particle morphology, gradation, mineralogy, specimen density, loading condition, stress path, and boundary conditions. The current literature lacks a three-dimensional (3D) systematic experimental study that investigates the influence of particle morphology, confining pressure, and specimen density on the failure mode of sheared sand. In this paper, surface texture, roundness, and sphericity of three uniform sands and glass beads with similar grain size were quantified by using 3D images of particles. In situ nondestructive 3D synchrotron microcomputed tomography (SMT) was used to monitor the deformation of medium-dense and very dense dry sand specimens that were tested under axisymmetric triaxial loading condition at 15 and 400 kPa confining pressures. The particles were identified and tracked in 3D as shearing progressed within the specimens, and maps of incremental particle translation and rotation were developed and used to uncover the relationship between particle morphology, specimen density, and confining pressure on the deformation and failure mode of sheared sand. This paper discusses the relationship between the failure mode and particle morphology, specimen density, and confining pressure.

  11. Influence of particle-phase state on the hygroscopic behavior of mixed organic-inorganic aerosols

    Science.gov (United States)

    Hodas, N.; Zuend, A.; Mui, W.; Flagan, R. C.; Seinfeld, J. H.

    2015-05-01

    Recent work has demonstrated that organic and mixed organic-inorganic particles can exhibit multiple phase states depending on their chemical composition and on ambient conditions such as relative humidity (RH). To explore the extent to which water uptake varies with particle-phase behavior, hygroscopic growth factors (HGFs) of nine laboratory-generated, organic and organic-inorganic aerosol systems with physical states ranging from well-mixed liquids to phase-separated particles to viscous liquids or semi-solids were measured with the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe at RH values ranging from 40 to 90%. Water-uptake measurements were accompanied by HGF and RH-dependent thermodynamic equilibrium calculations using the Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model. In addition, AIOMFAC-predicted growth curves are compared to several simplified HGF modeling approaches: (1) representing particles as ideal, well-mixed liquids; (2) forcing a single phase but accounting for non-ideal interactions through activity coefficient calculations; and (3) a Zdanovskii-Stokes-Robinson-like calculation in which complete separation of the inorganic and organic components is assumed at all RH values, with water uptake treated separately in each of the individual phases. We observed variability in the characteristics of measured hygroscopic growth curves across aerosol systems with differing phase behaviors, with growth curves approaching smoother, more continuous water uptake with decreasing prevalence of liquid-liquid phase separation and increasing oxygen : carbon ratios of the organic aerosol components. We also observed indirect evidence for the dehydration-induced formation of highly viscous semi-solid phases and for kinetic limitations to the crystallization of ammonium sulfate at low RH for sucrose-containing particles. AIOMFAC-predicted growth curves are generally in good agreement with the HGF

  12. Influence of particle phase state on the hygroscopic behavior of mixed organic-inorganic aerosols

    Science.gov (United States)

    Hodas, N.; Zuend, A.; Mui, W.; Flagan, R. C.; Seinfeld, J. H.

    2014-12-01

    Recent work has demonstrated that organic and mixed organic-inorganic particles can exhibit multiple phase states depending on their chemical composition and on ambient conditions such as relative humidity (RH). To explore the extent to which water uptake varies with particle phase behavior, hygroscopic growth factors (HGFs) of nine laboratory-generated, organic and organic-inorganic aerosol systems with physical states ranging from well-mixed liquids, to phase-separated particles, to viscous liquids or semi-solids were measured with the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe at RH values ranging from 40-90%. Water-uptake measurements were accompanied by HGF and RH-dependent thermodynamic equilibrium calculations using the Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model. In addition, AIOMFAC-predicted growth curves are compared to several simplified HGF modeling approaches: (1) representing particles as ideal, well-mixed liquids, (2) forcing a single phase, but accounting for non-ideal interactions through activity coefficient calculations, and (3) a Zdanovskii-Stokes-Robinson-like calculation in which complete separation between the inorganic and organic components is assumed at all RH values, with water-uptake treated separately in each of the individual phases. We observed variability in the characteristics of measured hygroscopic growth curves across aerosol systems with differing phase behaviors, with growth curves approaching smoother, more continuous water uptake with decreasing prevalence of liquid-liquid phase separation and increasing oxygen : carbon ratios of the organic aerosol components. We also observed indirect evidence for the dehydration-induced formation of highly viscous semi-solid phases and for kinetic limitations to the crystallization of ammonium sulfate at low RH for sucrose-containing particles. AIOMFAC-predicted growth curves are generally in good agreement with the HGF

  13. Laboratory-generated mixtures of mineral dust particles with biological substances: characterization of the particle mixing state and immersion freezing behavior

    Science.gov (United States)

    Augustin-Bauditz, Stefanie; Wex, Heike; Denjean, Cyrielle; Hartmann, Susan; Schneider, Johannes; Schmidt, Susann; Ebert, Martin; Stratmann, Frank

    2016-05-01

    Biological particles such as bacteria, fungal spores or pollen are known to be efficient ice nucleating particles. Their ability to nucleate ice is due to ice nucleation active macromolecules (INMs). It has been suggested that these INMs maintain their nucleating ability even when they are separated from their original carriers. This opens the possibility of an accumulation of such INMs in soils, resulting in an internal mixture of mineral dust and INMs. If particles from such soils which contain biological INMs are then dispersed into the atmosphere due to wind erosion or agricultural processes, they could induce ice nucleation at temperatures typical for biological substances, i.e., above -20 up to almost 0 °C, while they might be characterized as mineral dust particles due to a possibly low content of biological material. We conducted a study within the research unit INUIT (Ice Nucleation research UnIT), where we investigated the ice nucleation behavior of mineral dust particles internally mixed with INM. Specifically, we mixed a pure mineral dust sample (illite-NX) with ice active biological material (birch pollen washing water) and quantified the immersion freezing behavior of the resulting particles utilizing the Leipzig Aerosol Cloud Interaction Simulator (LACIS). A very important topic concerning the investigations presented here as well as for atmospheric application is the characterization of the mixing state of aerosol particles. In the present study we used different methods like single-particle aerosol mass spectrometry, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), and a Volatility-Hygroscopicity Tandem Differential Mobility Analyser (VH-TDMA) to investigate the mixing state of our generated aerosol. Not all applied methods performed similarly well in detecting small amounts of biological material on the mineral dust particles. Measuring the hygroscopicity/volatility of the mixed particles with the VH-TDMA was the most

  14. Laboratory-generated mixtures of mineral dust particles with biological substances: characterization of the particle mixing state and immersion freezing behavior

    Directory of Open Access Journals (Sweden)

    S. Augustin-Bauditz

    2016-05-01

    Full Text Available Biological particles such as bacteria, fungal spores or pollen are known to be efficient ice nucleating particles. Their ability to nucleate ice is due to ice nucleation active macromolecules (INMs. It has been suggested that these INMs maintain their nucleating ability even when they are separated from their original carriers. This opens the possibility of an accumulation of such INMs in soils, resulting in an internal mixture of mineral dust and INMs. If particles from such soils which contain biological INMs are then dispersed into the atmosphere due to wind erosion or agricultural processes, they could induce ice nucleation at temperatures typical for biological substances, i.e., above −20 up to almost 0 °C, while they might be characterized as mineral dust particles due to a possibly low content of biological material. We conducted a study within the research unit INUIT (Ice Nucleation research UnIT, where we investigated the ice nucleation behavior of mineral dust particles internally mixed with INM. Specifically, we mixed a pure mineral dust sample (illite-NX with ice active biological material (birch pollen washing water and quantified the immersion freezing behavior of the resulting particles utilizing the Leipzig Aerosol Cloud Interaction Simulator (LACIS. A very important topic concerning the investigations presented here as well as for atmospheric application is the characterization of the mixing state of aerosol particles. In the present study we used different methods like single-particle aerosol mass spectrometry, Scanning Electron Microscopy (SEM, Energy Dispersive X-ray analysis (EDX, and a Volatility–Hygroscopicity Tandem Differential Mobility Analyser (VH-TDMA to investigate the mixing state of our generated aerosol. Not all applied methods performed similarly well in detecting small amounts of biological material on the mineral dust particles. Measuring the hygroscopicity/volatility of the mixed particles with the VH

  15. Study of Acid Hydrolysis on Organic Waste: Understanding The Effect of Delignification and Particle Size

    Directory of Open Access Journals (Sweden)

    Anwar Nadiem

    2018-01-01

    Full Text Available Organic wastes from Swiettenia marcophylla L, Artocarpus heterophyllus L, Mangifera indica L, and Annona muricata L were prepared by grinding into 0.1875, 0.3750, 0.7500 mm of particle size and delignified by 2% NaOH at 80°C for 90 minutes. Acid dilution hydrolysis process with H2SO4 1% was performed at 150°C for 120 minutes in a closed reactor. The effect of particle size and delignification on and reducing sugar concentration were investigated. The result showed (1 leaves that can be used as raw material to produce hydrogen should have 38–49% cellulose and hemicellulose. (2 Reducing sugar concentration increased with particle size reduction and delignification. (3 the best result with the highest reducing sugar concentration was achieved by 0.1875 mm particle size with delignification on Annona muricata L.

  16. Final Report: "Collaborative Project. Understanding the Chemical Processes That Affect Growth Rates of Freshly Nucleated Particles"

    Energy Technology Data Exchange (ETDEWEB)

    Smith, James N. [NCAR, Boulder, CO (United States); McMurry, Peter H. [NCAR, Boulder, CO (United States)

    2015-11-12

    This final technical report describes our research activities that have, as the ultimate goal, the development of a model that explains growth rates of freshly nucleated particles. The research activities, which combine field observations with laboratory experiments, explore the relationship between concentrations of gas-phase species that contribute to growth and the rates at which those species are taken up. We also describe measurements of the chemical composition of freshly nucleated particles in a variety of locales, as well as properties (especially hygroscopicity) that influence their effects on climate. Our measurements include a self-organized, DOE-ARM funded project at the Southern Great Plains site, the New Particle Formation Study (NPFS), which took place during spring 2013. NPFS data are available to the research community on the ARM data archive, providing a unique suite observations of trace gas and aerosols that are associated with the formation and growth of atmospheric aerosol particles.

  17. Preliminary Understanding of Surface Plasmon-Enhanced Circular Dichroism Spectroscopy by Single Particle Imaging

    Science.gov (United States)

    Zhan, Kangshu

    Monitoring chiral optical signals of biomolecules as their conformation changes is an important means to study their structures, properties, and functions. Most measurements, however, are ensemble measurements because chiral optical signals from a single biomolecule is often too weak to be detected. In this dissertation, I present my early attempts to study conformational changes of adsorbed proteins by taking advantage of the enhanced electromagnetic (EM) field around a well-designed plasmonic nanofeature. In particular, I discuss the detection of protein adsorption and denaturation on metallic nanoparticles using single particle scattering and CD spectroscopic imaging. Particles of two distinctively different sizes were compared and two different sample protein molecules were studied. A combination of experimental and computational tools was used to simulate and interpret the collected scattering and CD results. The first chapter provides a brief overview of the state-of-art research in CD spectroscopic studies at the single particle level. Three different means to make particles capable of chiral detection are discussed. Various applications beyond single particle imaging are presented to showcase the potential of the described research project, beyond our immediate goals. The second chapter describes my initial characterization of large, metallic, anisotropic nanorods and the establishment of experimental procedures used later for spectrum reconstruction, data visualization and analysis. The physical shape and structure of the particles were imaged by scanning electron microscopy (SEM), the chemical composition by energy dispersive X-ray Spectroscopy (EDS), and the optical properties by darkfield microscopy. An experimental protocol was developed to connect information collected from separate techniques for the same particle, with the aims of discovering any possible structural-property correlation. The reproducibility of the single particle imaging method was

  18. Understanding the discrete element method simulation of non-spherical particles for granular and multi-body systems

    CERN Document Server

    Matuttis, Hans-Georg

    2014-01-01

    Gives readers a more thorough understanding of DEM and equips researchers for independent work and an ability to judge methods related to simulation of polygonal particles Introduces DEM from the fundamental concepts (theoretical mechanics and solidstate physics), with 2D and 3D simulation methods for polygonal particlesProvides the fundamentals of coding discrete element method (DEM) requiring little advance knowledge of granular matter or numerical simulationHighlights the numerical tricks and pitfalls that are usually only realized after years of experience, with relevant simple experiment

  19. On Understanding the Human Nature of Good and Bad Behavior in Business: A Behavioral Ethics Approach

    NARCIS (Netherlands)

    D. de Cremer (David)

    2009-01-01

    textabstractThe numerous scandals in business, such as those at AIG, Tyco, WorldCom, Enron and Ahold, have made all of us concerned about the emergence of unethical and irresponsible behavior in organizations. Such widespread corruption in business and politics has, as result, prompted a growth of

  20. The influence of particle geometry and the intermediate stress ratio on the shear behavior of granular materials

    OpenAIRE

    Xie, Y H.; Yang, Z X.; Barreto, D.; Jiang, M D.

    2017-01-01

    The behavior of granular materials is very complex in nature and depends on particle shape, stress path, fabric, density, particle size distribution, amongst others. This paper presents a study of the effect of particle geometry (aspect ratio) on the mechanical behaviour of granular materials using the Discrete Element Method (DEM). This study discusses 3D DEM simulations of conventional triaxial and true triaxial tests. The numerical experiments employ samples with different particle aspect ...

  1. Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere

    CERN Document Server

    Almeida, João; Kürten, Andreas; Ortega, Ismael K; Kupiainen-Määttä, Oona; Praplan, Arnaud P; Adamov, Alexey; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Donahue, Neil M; Downard, Andrew; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Guida, Roberto; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Henschel, Henning; Jokinen, Tuija; Junninen, Heikki; Kajos, Maija; Kangasluoma, Juha; Keskinen, Helmi; Kupc, Agnieszka; Kurtén, Theo; Kvashin, Alexander N; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Leppä, Johannes; Loukonen, Ville; Makhmutov, Vladimir; Mathot, Serge; McGrath, Matthew J; Nieminen, Tuomo; Olenius, Tinja; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Riipinen, Ilona; Rissanen, Matti; Rondo, Linda; Ruuskanen, Taina; Santos, Filipe D; Sarnela, Nina; Schallhart, Simon; Schnitzhofer, Ralf; Seinfeld, John H; Simon, Mario; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjo; Virtanen, Annele; Vrtala, Aron; Wagner, Paul E; Weingartner, Ernest; Wex, Heike; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Yli-Juuti, Taina; Carslaw, Kenneth S; Kulmala, Markku; Curtius, Joachim; Baltensperger, Urs; Vehkamaki, Hanna; Kirkby, Jasper

    2013-01-01

    Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei. Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes. Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases. However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere. It is thought that amines may enhance nucleation, but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates ...

  2. Understanding multiple levels of norms about teen pregnancy and their relationships to teens’ sexual behaviors

    OpenAIRE

    Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

    2014-01-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys...

  3. Numerical Study of Suspension HVOF Spray and Particle Behavior Near Flat and Cylindrical Substrates

    Science.gov (United States)

    Jadidi, M.; Yeganeh, A. Zabihi; Dolatabadi, A.

    2018-01-01

    In thermal spray processes, it is demonstrated that substrate shape and location have significant effects on particle in-flight behavior and coatings quality. In the present work, the suspension high-velocity oxygen fuel (HVOF) spraying process is modeled using a three-dimensional two-way coupled Eulerian-Lagrangian approach. Flat and cylindrical substrates are placed at different standoff distances, and particles characteristics near the substrates and upon impact are studied. Suspension is a mixture of ethanol, ethylene glycol, and mullite solid powder (3Al2O3·2SiO2) in this study. Suspension droplets with predefined size distribution are injected into the combustion chamber, and the droplet breakup phenomenon is simulated using Taylor analogy breakup model. Furthermore, the eddy dissipation model is used to model the premixed combustion of oxygen-propylene, and non-premixed combustion of oxygen-ethanol and oxygen-ethylene glycol. To simulate the gas phase turbulence, the realizable k-ɛ model is applied. In addition, as soon as the breakup and combustion phenomena are completed, the solid/molten mullite particles are tracked through the domain. It is shown that as the standoff distance increases the particle temperature and velocity decrease and the particle trajectory deviation becomes more significant. The effect of stagnation region on the particle velocity and temperature is also discussed in detail. The catch rate, which is defined as the ratio of the mass of landed particles to injected particles, is calculated for different substrate shapes and standoff distances in this study. The numerical results presented here is consistent with the experimental data in the literature for the same operating conditions.

  4. Collaborative Project: Understanding the Chemical Processes tat Affect Growth rates of Freshly Nucleated Particles

    Energy Technology Data Exchange (ETDEWEB)

    McMurry, Peter [Univ. of Minnesota, Minneapolis, MN (United States); Smuth, James [University Corporation for Atmospheric Research, Irvine, CA (United States)

    2015-11-12

    This final technical report describes our research activities that have, as the ultimate goal, the development of a model that explains growth rates of freshly nucleated particles. The research activities, which combine field observations with laboratory experiments, explore the relationship between concentrations of gas-phase species that contribute to growth and the rates at which those species are taken up. We also describe measurements of the chemical composition of freshly nucleated particles in a variety of locales, as well as properties (especially hygroscopicity) that influence their effects on climate.

  5. The effect of vibration on bed voidage behaviors in fluidized beds with large particles

    Directory of Open Access Journals (Sweden)

    H. Jin

    2007-09-01

    Full Text Available The effects of vibration parameters, operating conditions and material properties on bed voidage were investigated using an optical fiber probe approach in a vibrating fluidized bed with a diameter of 148 mm. Variables studied included frequency (0-282 s-1, amplitude (0 mm-1 mm, bed height (0.1 m-0.4 m as well as four kinds of particles (belonging to Geldart's B and D groups. The axial and radial voidage distribution with vibration is compared with that without vibration, which shows vibration can aid in the fluidization behaviors of particles. For a larger vibration amplitude, the vibration seriously affects bed voidage. The vibration energy can damp out for particle layers with increasing the bed height. According to analysis of experimental data, an empirical correlation for predicting bed voidage, giving good agreement with the experimental data and a deviation within ±15%, was proposed.

  6. Analysis of secondary particle behavior in multiaperture, multigrid accelerator for the ITER neutral beam injector.

    Science.gov (United States)

    Mizuno, T; Taniguchi, M; Kashiwagi, M; Umeda, N; Tobari, H; Watanabe, K; Dairaku, M; Sakamoto, K; Inoue, T

    2010-02-01

    Heat load on acceleration grids by secondary particles such as electrons, neutrals, and positive ions, is a key issue for long pulse acceleration of negative ion beams. Complicated behaviors of the secondary particles in multiaperture, multigrid (MAMuG) accelerator have been analyzed using electrostatic accelerator Monte Carlo code. The analytical result is compared to experimental one obtained in a long pulse operation of a MeV accelerator, of which second acceleration grid (A2G) was removed for simplification of structure. The analytical results show that relatively high heat load on the third acceleration grid (A3G) since stripped electrons were deposited mainly on A3G. This heat load on the A3G can be suppressed by installing the A2G. Thus, capability of MAMuG accelerator is demonstrated for suppression of heat load due to secondary particles by the intermediate grids.

  7. In situ observation of the role of alumina particles on the crystallization behavior of slags

    Energy Technology Data Exchange (ETDEWEB)

    Orrling, C.

    2000-09-01

    The confocal laser scanning microscope (CLSM) allows crystallization behavior in liquid slags to he observed in situ at high temperatures. Slags in the lime-silica-alumina-magnesia system are easily tinder cooled and it is possible to construct time temperature transformation (TTT) diagrams for this system. The presence of solid alumina particles its these liquid slags was studied to determine if these particles act as heterogeneous nucleation sites that cause she precipitation of solid material within slags. The introduction of alumina particles reduced the incubation time for the onset of crystallization and increased the temperature at which crystallization was observed in the slags to close to the liquidus temperature for the slag. Crystal growth rates are in a good agreement with Ivantsov's solution of the problem of diffusion controlled dendritic growth. Alumina appears to be a potent nucleating agent in the slag systems that were studied. (author)

  8. The Crucible simulation: Behavioral simulation improves clinical leadership skills and understanding of complex health policy change.

    Science.gov (United States)

    Cohen, Daniel; Vlaev, Ivo; McMahon, Laurie; Harvey, Sarah; Mitchell, Andy; Borovoi, Leah; Darzi, Ara

    2017-05-11

    The Health and Social Care Act 2012 represents the most complex National Health Service reforms in history. High-quality clinical leadership is important for successful implementation of health service reform. However, little is known about the effectiveness of current leadership training. This study describes the use of a behavioral simulation to improve the knowledge and leadership of a cohort of medical doctors expected to take leadership roles in the National Health Service. A day-long behavioral simulation (The Crucible) was developed and run based on a fictitious but realistic health economy. Participants completed pre- and postsimulation questionnaires generating qualitative and quantitative data. Leadership skills, knowledge, and behavior change processes described by the "theory of planned behavior" were self-assessed pre- and postsimulation. Sixty-nine medical doctors attended. Participants deemed the simulation immersive and relevant. Significant improvements were shown in perceived knowledge, capability, attitudes, subjective norms, intentions, and leadership competency following the program. Nearly one third of participants reported that they had implemented knowledge and skills from the simulation into practice within 4 weeks. This study systematically demonstrates the effectiveness of behavioral simulation for clinical management training and understanding of health policy reform. Potential future uses and strategies for analysis are discussed. High-quality care requires understanding of health systems and strong leadership. Policymakers should consider the use of behavioral simulation to improve understanding of health service reform and development of leadership skills in clinicians, who readily adopt skills from simulation into everyday practice.

  9. Activity behavior of a HPLC column including α-chymotrypsin immobilized monosized-porous particles

    International Nuclear Information System (INIS)

    Bilici, Z.; Camli, S.T.; Unsal, E.; Tuncel, A.

    2004-01-01

    In this study, a polymer-based, α-chymotrypsin (CT) immobilized HPLC column was prepared as a potential material for affinity-HPLC and chiral separation applications. Monosized-macroporous particles were synthesized as the support material by a relatively new polymerization protocol, the so-called, 'modified seeded polymerization'. The particles were obtained in the form of styrene-glycidyl methacrylate- divinylbenzene terpolymer approximately 11 μm in size. The particles were treated with aqueous ammonia to have primary amine groups on the porous surface. The amine functionalized particles were reacted by glutaraldehyde and the enzyme, CT, was covalently attached. CT carrying monosized-porous particles were slurry packed into the HPLC column 50 mmx4.6 mm in size. Since the activity behavior of immobilized CT played an important role in the enantiomeric separations performed by similar columns, the enzymatic activity behavior of the column produced by our protocol was determined. For this purpose, HPLC column was used as a packed bed reactor and the enzymatic reaction was continuously followed by measuring the absorbance of the output flow by the UV-detector of HPLC. S-shaped absorbance-time curves were obtained by monitoring the reactor output both in dynamic and steady-state periods. The columns with relatively lower immobilized enzyme content were more sensitive to the changes in the operating conditions and responded with more appreciable substrate conversion changes. The maximum reaction rate of the immobilized enzyme was estimated as approximately 25% of the free one by the mathematical model describing the activity behavior of the column. No significant loss was observed in the activity of the immobilized enzyme during the course of the experiments

  10. Effect of particle size distribution and concentration on flow behavior of dense slurries

    Czech Academy of Sciences Publication Activity Database

    Vlasák, Pavel; Chára, Zdeněk

    2011-01-01

    Roč. 29, č. 1 (2011), s. 53-65 ISSN 0272-6351 R&D Projects: GA ČR(CZ) GAP105/10/1574 Institutional research plan: CEZ:AV0Z20600510 Keywords : concentration effect * dense complex slurry * experimental investigation * flow behavior * particle size distribution effect * pressure drop Subject RIV: BK - Fluid Dynamics Impact factor: 0.545, year: 2011

  11. An Interactive Computer Model for Improved Student Understanding of Random Particle Motion and Osmosis

    Science.gov (United States)

    Kottonau, Johannes

    2011-01-01

    Effectively teaching the concepts of osmosis to college-level students is a major obstacle in biological education. Therefore, a novel computer model is presented that allows students to observe the random nature of particle motion simultaneously with the seemingly directed net flow of water across a semipermeable membrane during osmotic…

  12. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules.

    Science.gov (United States)

    Schobesberger, Siegfried; Junninen, Heikki; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

    2013-10-22

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molecules and then form growing clusters of one to three sulfuric acid molecules plus one to four oxidized organics. Most of these organic compounds retain 10 carbon atoms, and some of them are remarkably highly oxidized (oxygen-to-carbon ratios up to 1.2). The average degree of oxygenation of the organic compounds decreases while the clusters are growing. Our measurements therefore connect oxidized organics directly, and in detail, with the very first steps of new particle formation and their growth between 1 and 2 nm in a controlled environment. Thus, they confirm that oxidized organics are involved in both the formation and growth of particles under ambient conditions.

  13. A Visual Analytics Approach for Detecting and Understanding Anomalous Resident Behaviors in Smart Healthcare

    Directory of Open Access Journals (Sweden)

    Zhifang Liao

    2017-03-01

    Full Text Available With the development of science and technology, it is possible to analyze residents’ daily behaviors for the purpose of smart healthcare in the smart home environment. Many researchers have begun to detect residents’ anomalous behaviors and assess their physical condition, but these approaches used by the researchers are often caught in plight caused by a lack of ground truth, one-sided analysis of behavior, and difficulty of understanding behaviors. In this paper, we put forward a smart home visual analysis system (SHVis to help analysts detect and comprehend unusual behaviors of residents, and predict the health information intelligently. Firstly, the system classifies daily activities recorded by sensor devices in smart home environment into different categories, and discovers unusual behavior patterns of residents living in this environment by using various characteristics extracted from those activities and appropriate unsupervised anomaly detection algorithm. Secondly, on the basis of figuring out the residents’ anomaly degree of every date, we explore the daily behavior patterns and details with the help of several visualization views, and compare and analyze residents’ activities of various dates to find the reasons why residents act unusually. In the case study of this paper, we analyze residents’ behaviors that happened over two months and find unusual indoor behaviors and give health advice to the residents.

  14. Meta-Analysis of the Reasoned Action Approach (RAA) to Understanding Health Behaviors.

    Science.gov (United States)

    McEachan, Rosemary; Taylor, Natalie; Harrison, Reema; Lawton, Rebecca; Gardner, Peter; Conner, Mark

    2016-08-01

    Reasoned action approach (RAA) includes subcomponents of attitude (experiential/instrumental), perceived norm (injunctive/descriptive), and perceived behavioral control (capacity/autonomy) to predict intention and behavior. To provide a meta-analysis of the RAA for health behaviors focusing on comparing the pairs of RAA subcomponents and differences between health protection and health-risk behaviors. The present research reports a meta-analysis of correlational tests of RAA subcomponents, examination of moderators, and combined effects of subcomponents on intention and behavior. Regressions were used to predict intention and behavior based on data from studies measuring all variables. Capacity and experiential attitude had large, and other constructs had small-medium-sized correlations with intention; all constructs except autonomy were significant independent predictors of intention in regressions. Intention, capacity, and experiential attitude had medium-large, and other constructs had small-medium-sized correlations with behavior; intention, capacity, experiential attitude, and descriptive norm were significant independent predictors of behavior in regressions. The RAA subcomponents have utility in predicting and understanding health behaviors.

  15. Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere.

    Science.gov (United States)

    Almeida, João; Schobesberger, Siegfried; Kürten, Andreas; Ortega, Ismael K; Kupiainen-Määttä, Oona; Praplan, Arnaud P; Adamov, Alexey; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Donahue, Neil M; Downard, Andrew; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Guida, Roberto; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Henschel, Henning; Jokinen, Tuija; Junninen, Heikki; Kajos, Maija; Kangasluoma, Juha; Keskinen, Helmi; Kupc, Agnieszka; Kurtén, Theo; Kvashin, Alexander N; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Leppä, Johannes; Loukonen, Ville; Makhmutov, Vladimir; Mathot, Serge; McGrath, Matthew J; Nieminen, Tuomo; Olenius, Tinja; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Riipinen, Ilona; Rissanen, Matti; Rondo, Linda; Ruuskanen, Taina; Santos, Filipe D; Sarnela, Nina; Schallhart, Simon; Schnitzhofer, Ralf; Seinfeld, John H; Simon, Mario; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjo; Virtanen, Annele; Vrtala, Aron; Wagner, Paul E; Weingartner, Ernest; Wex, Heike; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Yli-Juuti, Taina; Carslaw, Kenneth S; Kulmala, Markku; Curtius, Joachim; Baltensperger, Urs; Worsnop, Douglas R; Vehkamäki, Hanna; Kirkby, Jasper

    2013-10-17

    Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei. Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes. Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases. However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere. It is thought that amines may enhance nucleation, but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates more than 1,000-fold compared with ammonia, sufficient to account for the particle formation rates observed in the atmosphere. Molecular analysis of the clusters reveals that the faster nucleation is explained by a base-stabilization mechanism involving acid-amine pairs, which strongly decrease evaporation. The ion-induced contribution is generally small, reflecting the high stability of sulphuric acid-dimethylamine clusters and indicating that galactic cosmic rays exert only a small influence on their formation, except at low overall formation rates. Our experimental measurements are well reproduced by a dynamical model based on quantum chemical calculations of binding energies of molecular clusters, without any fitted parameters. These results show that, in regions of the atmosphere near amine sources, both amines and sulphur dioxide should be considered when assessing the impact of anthropogenic activities on particle formation.

  16. Diet as a factor in behavioral radiation protection following exposure to heavy particles

    Science.gov (United States)

    Rabin, Bernard M.; Shukitt-Hale, Barbara; Joseph, James; Todd, Paul

    2005-01-01

    Major risks associated with radiation exposures on deep space missions include carcinogenesis due to heavy-particle exposure of cancer-prone tissues and performance decrements due to neurological damage produced by heavy particles. Because exposure to heavy particles can cause oxidative stress, it is possible that antioxidants can be used to mitigate these risks (and possibly some health risks of microgravity). To assess the capacity of antioxidant diets to mitigate the effects of exposure to heavy particles, rats were maintained on antioxidant diets containing 2% blueberry or strawberry extract or a control diet for 8 weeks prior to exposure to 1.5 or 2.0 Gy of accelerated iron particles at Brookhaven National Laboratory. Following irradiation rats were tested on a series of behavioral tasks: amphetamine-induced taste aversion learning, operant responding and spatial learning and memory. The results indicated that the performance of the irradiated rats maintained on the antioxidant diets was, in general, significantly better than that of the control animals, although the effectiveness of the diets ameliorating the radiation-induced deterioration in performance varied as a function of both the specific diet and the specific endpoint. In addition, animals fed antioxidant diets prior to exposure showed reduced heavy particle-induced tumorigenesis one year after exposure compared to the animals fed the control diet. These results suggest that antioxidant diets have the potential to serve as part of a system designed to provide protection to astronauts against the effects of heavy particles on exploratory missions outside the magnetic field of the earth.

  17. Understanding Knowledge Sharing Behavior: An Examination of the Extended Model of Theory of Planned Behavior

    Directory of Open Access Journals (Sweden)

    Sabrina O. Sihombing

    2011-03-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Knowledge is recognized as one valuable asset for many organizations. Thus, knowledge-sharing is one of important activities in many organizations, including university. Knowledge sharing is defined as activities of transferring or disseminating organizationally relevant information, ideas, suggestions, and expertise with one another. This research applied Christian values as a moderating variable in the framework of theory of planned behavior. The aims of this research to assess applicability of the theory of planned behavior to predict knowledge sharing and to examine the effects of Christian values in the relationship between attitude and intention to share knowledge. A self-administered questionnaire was used to collect the data for this study. The data was then analyzed using structural equation modeling. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  18. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules

    CERN Document Server

    Schobesberger, Siegfried; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

    2013-01-01

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molec...

  19. The Psychology of Isolated and Confined Environments: Understanding Human Behavior in Antarctica.

    Science.gov (United States)

    Palinkas, Lawrence A.

    2003-01-01

    Reviews lessons learned from research in Antarctica with relevance to understanding human behavior in other isolated and confined environments. Outlines four distinct characteristics of psychosocial adaptation to such environments and discusses some of the benefits for individuals seeking challenging experiences. (Contains references.) (SLD)

  20. A neurogenetics approach to understanding individual differences in brain, behavior, and risk for psychopathology.

    Science.gov (United States)

    Bogdan, R; Hyde, L W; Hariri, A R

    2013-03-01

    Neurogenetics research has begun to advance our understanding of how genetic variation gives rise to individual differences in brain function, which, in turn, shapes behavior and risk for psychopathology. Despite these advancements, neurogenetics research is currently confronted by three major challenges: (1) conducting research on individual variables with small effects, (2) absence of detailed mechanisms, and (3) a need to translate findings toward greater clinical relevance. In this review, we showcase techniques and developments that address these challenges and highlight the benefits of a neurogenetics approach to understanding brain, behavior and psychopathology. To address the challenge of small effects, we explore approaches including incorporating the environment, modeling epistatic relationships and using multilocus profiles. To address the challenge of mechanism, we explore how non-human animal research, epigenetics research and genome-wide association studies can inform our mechanistic understanding of behaviorally relevant brain function. Finally, to address the challenge of clinical relevance, we examine how neurogenetics research can identify novel therapeutic targets and for whom treatments work best. By addressing these challenges, neurogenetics research is poised to exponentially increase our understanding of how genetic variation interacts with the environment to shape the brain, behavior and risk for psychopathology.

  1. Bridging Models and Business: Understanding heterogeneity in hidden drivers of customer purchase behavior

    NARCIS (Netherlands)

    E. Korkmaz (Evsen)

    2014-01-01

    markdownabstract__Abstract__ Recent years have seen many advances in quantitative models in the marketing literature. Even though these advances enable model building for a better understanding of customer purchase behavior and customer heterogeneity such that firms develop optimal targeting and

  2. An Integrative Model for Understanding Team Organizational Citizenship Behavior: Its Antecedents and Consequences for Educational Teams

    Science.gov (United States)

    Somech, Anit; Khotaba, Soha

    2017-01-01

    Purpose: The purpose of this paper is to use a model to broaden the understanding of the organizational citizenship behavior (OCB) phenomenon in educational teams and examines team OCB's mediating role in the relation of the contextual variables of team justice climate (distributive justice, procedural justice, interpersonal justice) to team…

  3. Vanadium Inhalation in a Mouse Model for the Understanding of Air-Suspended Particle Systemic Repercussion

    Directory of Open Access Journals (Sweden)

    T. I. Fortoul

    2011-01-01

    Full Text Available There is an increased concern about the health effects that air-suspended particles have on human health which have been dissected in animal models. Using CD-1 mouse, we explore the effects that vanadium inhalation produce in different tissues and organs. Our findings support the systemic effects of air pollution. In this paper, we describe our findings in different organs in our conditions and contrast our results with the literature.

  4. Understanding multiple levels of norms about teen pregnancy and their relationships to teens’ sexual behaviors

    Science.gov (United States)

    Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

    2014-01-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys’ perceived norms, while peer network norms predict girls’ perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens’ likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys’ contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors. PMID:25104920

  5. Understanding multiple levels of norms about teen pregnancy and their relationships to teens' sexual behaviors.

    Science.gov (United States)

    Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

    2014-06-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys' perceived norms, while peer network norms predict girls' perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens' likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys' contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors.

  6. Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron imaging

    Science.gov (United States)

    Howe, Jane Y.; Allard, Lawrence F.; Bigelow, Wilbur C.; Demers, Hendrix; Overbury, Steven H.

    2014-11-01

    By coupling techniques of simultaneous secondary (SE) and transmitted electron (TE) imaging at high resolution in a modern scanning transmission electron microscope (STEM), with the ability to heat specimens using a highly stable MEMS-based heating platform, we obtained synergistic information to clarify the behavior of catalysts during in situ thermal treatments. Au/iron oxide catalyst 'leached' to remove surface Au was heated to temperatures as high as 700°C. The Fe2O3 support particle structure tended to reduce to Fe3O4 and formed surface terraces; the formation, coalescence, and mobility of 1- to 2-nm particles on the terraces were characterized in SE, STEM-ADF, and TEM-BF modes. If combined with simultaneous nanoprobe spectroscopy, this approach will open the door to a new way of studying the kinetics of nano-scaled phenomena.

  7. The properties and behavior of α-pinene secondary organic aerosol particles exposed to ammonia under dry conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bell, David M.; Imre, D.; Martin, Scot T.; Zelenyuk-Imre, Alla

    2017-01-01

    Chemical transformations and aging of secondary organic aerosol (SOA) particles can alter their physical and chemical properties, including particle morphology. Ammonia, one of the common atmospheric reactive constituents, can react with SOA particles, changing their properties and behavior. At low relative humidity NH3 uptake by α-pinene SOA particles appears to be limited to the particle surface, which suggests that the reacted particles might not be homogeneous and have complex morphology. Here, we present a study aimed at detailed characterization of the effect of ammonia on the composition, density, morphology, shape, and evaporation kinetics of α-pinene SOA particles. We find that a small amount of NH3 diffuses and reacts throughout the particles bulk, while most of the ammoniated products result from the reaction of NH3 with carboxylic acids on the particle surface, leading to a slight increase in particle size. We show that the reaction products form a solid semi-volatile coating that is a few nanometers thick. This solid coating prevents coagulating particles from coalescing for over two days. However, when the gas phase is diluted this semi-volatile coating evaporates in minutes, which is ensued by rapid coalescence. The ammoniated products in the particle bulk affect particles evaporation kinetics, more so for the smaller particles that contain higher fraction of ammoniated products.

  8. Facebook tells me so: applying the theory of planned behavior to understand partner-monitoring behavior on Facebook.

    Science.gov (United States)

    Darvell, Millie J; Walsh, Shari P; White, Katherine M

    2011-12-01

    The social networking site (SNS) Facebook is becoming increasingly recognized as a medium through which individuals can investigate and monitor others' activities. However, little is known about whether Facebook monitoring behavior occurs within romantic relationships and, accordingly, the psychological predictors of this behavior. The present study employed an extended theory of planned behavior (TPB) framework including self-esteem, partner trust, and demographic characteristics, to predict frequent Facebook partner-monitoring. Facebook users (N=244) in romantic relationships completed measures assessing the standard TPB constructs (attitude, subjective norm, and perceived behavioral control), additional predictor variables (self-esteem and partner trust), and demographic characteristics (age, gender, relationship length, daily Facebook logins, and time spent per login). One week later, participants reported their level of Facebook partner-monitoring during the previous week. Regression analyses supported the standard TPB constructs of attitude and subjective norm in predicting intentions to engage in frequent Facebook partner-monitoring, with intention, in turn, predicting behavior. Partner trust, but not self-esteem, significantly predicted frequent Facebook partner-monitoring intentions. Of the demographic characteristics, daily Facebook logins significantly predicted both intention and behavior and, unexpectedly, relationship length directly affected behavior. Overall, the current study revealed that frequent Facebook partner-monitoring is influenced by attitudinal, normative, and relational factors and, potentially, increased visits to Facebook. These findings provide a new understanding of an individual's use of the world's leading SNS to monitor their partner's activities and provide a foundation for future studies to investigate the potential negative implications this activity may have for those in romantic relationships.

  9. Understanding of increased diffuse scattering in regular arrays of fluctuating resonant particles

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Petrov, Mihail; Lavrinenko, Andrei

    2015-01-01

    to promising technological implementations with cost-efficient methods of large-scale chemical nanoparticles synthesis as well as their self-organization. Random fluctuations of the particles size, shape, and/or composition are inevitable not only in the bottom-up synthesis, but also in conventional electron...... beam and photolithography fabrication. Despite the significant progress in large-scale fabrication, modeling and effective properties prediction of random/amorphous metamaterials and metasurfaces is still a challenge, which we address here. We present our results on analytical modelling of metasurfaces...

  10. Monte Carlo Simulation for particle behavior of recycling neutrals in a tokamak divertor region

    International Nuclear Information System (INIS)

    Kim, D. K.; Hong, S. H.

    1997-01-01

    The steady-state behavior of recycling neutral atoms in a tokamak edge region has been analyzed through a two-dimensional Monte Carlo simulation. A particle tracking algorithm used in earlier research on the neutral particle transport is applied to this Monte Carlo simulation in order to perform more accurate calculations with the EDGETRAN code which was previously developed for a two-dimensional edge plasma transport in the authors' laboratory. The physical model of neutral recycling includes charge-exchange and ionization interactions between plasmas and neutral atoms. The reflection processes of incident particles on the device wall are described by empirical formulas. Calculations for density, energy, and velocity distributions of neutral deuterium-tritium atoms have been carried out for a medium-sized tokamak with a double-null configuration based on the KT-2 conceptual design. The input plasma parameters such as plasma density, ion and electron temperatures, and ion fluid velocity are provided from the EDGETRAN calculations. As a result of the present numerical analysis, it is noticed that a significant drop of the neutral atom density appears in the region of high plasma density and that the similar distribution of neutral energy to that of plasma ions is present as frequently reported in other studies. Relations between edge plasma conditions and the neutral recycling behavior are discussed from the numerical results obtained herein. (author)

  11. Understanding how discrete populations of hypothalamic neurons orchestrate complicated behavioral states

    Directory of Open Access Journals (Sweden)

    Allison eGraebner

    2015-08-01

    Full Text Available A major question in systems neuroscience is how a single population of neurons can interact with the rest of the brain to orchestrate complex behavioral states. The hypothalamus contains many such discrete neuronal populations that individually regulate arousal, feeding, and drinking. For example, hypothalamic neurons that express hypocretin (Hcrt neuropeptides can sense homeostatic and metabolic factors affecting wakefulness and orchestrate organismal arousal. Neurons that express agouti-related protein (AgRP can sense the metabolic needs of the body and orchestrate a state of hunger. The organum vasculosum of the lamina terminalis (OVLT can detect the hypertonicity of blood and orchestrate a state of thirst. Each hypothalamic population is sufficient to generate complicated behavioral states through the combined efforts of distinct efferent projections. The principal challenge to understanding these brain systems is therefore to determine the individual roles of each downstream projection for each behavioral state. In recent years, the development and application of temporally precise, genetically encoded tools have greatly improved our understanding of the structure and function of these neural systems. This review will survey recent advances in our understanding of how these individual hypothalamic populations can orchestrate complicated behavioral states due to the combined efforts of individual downstream projections.

  12. Caustic-based approach to understanding bunching dynamics and current spike formation in particle bunches

    Directory of Open Access Journals (Sweden)

    T. K. Charles

    2016-10-01

    Full Text Available Current modulations, current spikes, and current horns, are observed in a range of accelerator physics applications including strong bunch compression in Free Electron Lasers and linear colliders, trains of microbunching for terahertz radiation, microbunching instability and many others. This paper considers the fundamental mechanism that drives intense current modulations in dispersive regions, beyond the common explanation of nonlinear and higher-order effects. Under certain conditions, neighboring electron trajectories merge to form caustics, and often result in characteristic current spikes. Caustic lines and surfaces are regions of maximum electron density, and are witnessed in accelerator physics as folds in phase space of accelerated bunches. We identify the caustic phenomenon resulting in cusplike current profiles and derive an expression which describes the conditions needed for particle-bunch caustic formation in dispersive regions. The caustic expression not only reveals the conditions necessary for caustics to form but also where in longitudinal space the caustics will form. Particle-tracking simulations are used to verify these findings. We discuss the broader implications of this work including how to utilize the caustic expression for manipulation of the longitudinal phase space to achieve a desired current profile shape.

  13. Hygral Behavior of Superabsorbent Polymers with Various Particle Sizes and Cross-Linking Densities

    Directory of Open Access Journals (Sweden)

    Kyong-Ku Yun

    2017-11-01

    Full Text Available This study focuses on investigating the effects of particle size and cross-linking density on the hygral behavior of superabsorbent polymers (SAPs, which are increasingly used as an internal curing material for high-performance concrete. Four SAPs with different mean particle diameters and cross-linking densities were tested under controlled wetting and drying conditions to measure free absorption and desorption kinetics. Absorption capacities of SAPs under actual mixing conditions were additionally measured and verified by means of mortar flow and semi-adiabatic hydration heat measurements. In addition, the effects of SAP type and dosage (i.e., 0.2, 0.4, and 0.6% by mass of cement on the mechanical properties of hardened mortar were assessed. The results indicated that: (1 the absorption capacity increased with decreased cross-linking density and increased particle size under both load-free and mixing conditions; and (2 the greater the cross-linking density and the lower the particle size, the shorter the desorption time. It was also confirmed that while the early-age mechanical properties were more related with the gel strength of swollen SAP, the later-age mechanical properties were more affected by the water retention capacity and spatial distribution of SAP in the matrix.

  14. Oxidation behavior of TiC particle-reinforced 304 stainless steel

    International Nuclear Information System (INIS)

    Wu Qianlin; Zhang Jianqiang; Sun Yangshan

    2010-01-01

    TiC particle-reinforced 304 stainless steels were prepared using a new developed in situ technology and exhibited the uniform distribution of TiC particles in the matrix. The oxidation behavior of 304SS-2TiC and 304SS-6TiC (all in weight percentage) was compared with that of 304SS at 850 deg. C in air for 96 h using thermogravimetry analysis. For 304SS, the rate of weight gain was very slow initially, but accelerated suddenly to a very high level, forming breakaway oxidation. The addition of TiC particles to 304SS resulted in no breakaway oxidation and maintained a low oxidation rate in the whole reaction time investigated. Examination of oxide scale morphology and cross-section analysis by scanning electron microscopy and optical microscopy showed a significant scale spallation and a deep oxide penetration in the case of 304SS, but a rather continuous, dense and adherent oxide layer formed on the surface of TiC particle-reinforced alloys. XRD analysis revealed the presence of Cr 2 O 3 together with spinel-type oxides in the oxide scale. For TiC-containing alloys, fine TiO 2 was also found on the surface and the amount of this oxide increased with TiC addition. The TiC addition developed finer matrix structure before oxidation, which accelerates chromium diffusion. As a result, scale adherence was improved and oxidation resistance was increased.

  15. Investigation of flow regime in debris bed formation behavior with nonspherical particles

    Directory of Open Access Journals (Sweden)

    Songbai Cheng

    2018-02-01

    Full Text Available It is important to clarify the characteristics of flow regimes underlying the debris bed formation behavior that might be encountered in core disruptive accidents of sodium-cooled fast reactors. Although in our previous publications, by applying dimensional analysis technique, an empirical model, with its reasonability confirmed over a variety of parametric conditions, has been successfully developed to predict the regime transition and final bed geometry formed, so far this model is restricted to predictions of debris mixtures composed of spherical particles. Focusing on this aspect, in this study a new series of experiments using nonspherical particles have been conducted. Based on the knowledge and data obtained, an extension scheme is suggested with the purpose of extending the base model to cover the particle-shape influence. Through detailed analyses and given our current range of experimental conditions, it is found that, by coupling the base model with this scheme, respectable agreement between experiments and model predictions for the regime transition can be achieved for both spherical and nonspherical particles. Knowledge and evidence from our work might be utilized for the future improvement of design of an in-vessel core catcher as well as the development and verification of sodium-cooled fast reactor severe accident analysis codes in China.

  16. Investigation of the hydrodynamic behavior of diatom aggregates using particle image velocimetry.

    Science.gov (United States)

    Xiao, Feng; Li, Xiaoyan; Lam, Kitming; Wang, Dongsheng

    2012-01-01

    The hydrodynamic behavior of diatom aggregates has a significant influence on the interactions and flocculation kinetics of algae. However, characterization of the hydrodynamics of diatoms and diatom aggregates in water is rather difficult. In this laboratory study, an advanced visualization technique in particle image velocimetry (PIV) was employed to investigate the hydrodynamic properties of settling diatom aggregates. The experiments were conducted in a settling column filled with a suspension of fluorescent polymeric beads as seed tracers. A laser light sheet was generated by the PIV setup to illuminate a thin vertical planar region in the settling column, while the motions of particles were recorded by a high speed charge-coupled device (CCD) camera. This technique was able to capture the trajectories of the tracers when a diatom aggregate settled through the tracer suspension. The PIV results indicated directly the curvilinear feature of the streamlines around diatom aggregates. The rectilinear collision model largely overestimated the collision areas of the settling particles. Algae aggregates appeared to be highly porous and fractal, which allowed streamlines to penetrate into the aggregate interior. The diatom aggregates have a fluid collection efficiency of 10%-40%. The permeable feature of aggregates can significantly enhance the collisions and flocculation between the aggregates and other small particles including algal cells in water.

  17. Human behavior understanding for assisted living by means of hierarchical context free grammars

    Science.gov (United States)

    Rosani, A.; Conci, N.; De Natale, F. G. B.

    2014-03-01

    Human behavior understanding has attracted the attention of researchers in various fields over the last years. Recognizing behaviors with sufficient accuracy from sensors analysis is still an unsolved problem, because of many reasons, including the low accuracy of the data, differences in the human behaviors as well as the gap between low-level sensors data and high-level scene semantics. In this context, an application that is attracting the interest of both public and industrial entities is the possibility to allow elderly or physically impaired people conducting a normal life at home. Ambient intelligence (AmI) technologies, intended as the possibility of automatically detecting and reacting to the status of the environment and of the persons, is probably the major enabling factor for the achievement of such an ambitious objective. AmI technologies require suitable networks of sensors and actuators, as well as adequate processing and communication technologies. In this paper we propose a solution based on context free grammars for human behavior understanding with an application to assisted living. First, the grammars of the different actions performed by a person in his/her daily life are discovered. Then, a longterm analysis of the behavior is used to generate a control grammar, taking care of the context when an action is performed, and adding semantics. The proposed framework is tested on a dataset acquired in a real environment and compared with state of the art methods already available for the problem considered.

  18. Transient Liquid Phase Behavior of Sn-Coated Cu Particles and Chip Bonding using Paste Containing the Particles

    Directory of Open Access Journals (Sweden)

    Hwang Jun Ho

    2017-06-01

    Full Text Available Sn-coated Cu particles were prepared as a filler material for transient liquid phase (TLP bonding. The thickness of Sn coating was controlled by controlling the number of plating cycles. The Sn-coated Cu particles best suited for TLP bonding were fabricated by Sn plating thrice, and the particles showed a pronounced endothermic peak at 232°C. The heating of the particles for just 10 s at 250°C destroyed the initial core-shell structure and encouraged the formation of Cu-Sn intermetallic compounds. Further, die bonding was also successfully performed at 250°C under a slight bonding pressure of around 0.1 MPa using a paste containing the particles. The bonding time of 30 s facilitated the bonding of Sn-coated Cu particles to the Au surface and also increased the probability of network formation between particles.

  19. Understanding and Quantifying the Reactivity of Energetic NanoParticles and NanoComposites

    Science.gov (United States)

    2015-01-05

    The Effects of Aluminum Hydride as a Fuel Supplement on the Performance of Traditional NanoThermites, Journal of Propulsion and Power (06 2013...Sullivan, , K-S. Lee,, Y. H. Kim, , R. Zahaf, , M. R. Zachariah, D. Lee . Microstructural Behavior of the Alumina Shell and Aluminum CoreBefore and...After Melting of Aluminum Nanoparticles, J Phys Chem , (01 2012): 404. doi: N. Piekiel, M.R. Zachariah. N.W. Piekiel and M.R. ZachariahDecomposition

  20. Phase Behaviors of Reservoir Fluids with Capillary Eff ect Using Particle Swarm Optimization

    KAUST Repository

    Ma, Zhiwei

    2013-05-06

    The study of phase behavior is important for the oil and gas industry. Many approaches have been proposed and developed for phase behavior calculation. In this thesis, an alternative method is introduced to study the phase behavior by means of minimization of Helmholtz free energy. For a system at fixed volume, constant temperature and constant number of moles, the Helmholtz free energy reaches minimum at the equilibrium state. Based on this theory, a stochastic method called Particle Swarm Optimization (PSO) algorithm, is implemented to compute the phase diagrams for several pure component and mixture systems. After comparing with experimental and the classical PT-ash calculation, we found the phase diagrams obtained by minimization of the Helmholtz Free Energy approach match the experimental and theoretical diagrams very well. Capillary effect is also considered in this thesis because it has a significant influence on the phase behavior of reservoir fluids. In this part, we focus on computing the phase envelopes, which consists of bubble and dew point lines. Both fixed and calculated capillary pressure from the Young-Laplace equation cases are introduced to study their effects on phase envelopes. We found that the existence of capillary pressure will change the phase envelopes. Positive capillary pressure reduces the dew point and bubble point temperatures under the same pressure condition, while the negative capillary pressure increases the dew point and bubble point temperatures. In addition, the change of contact angle and pore radius will affect the phase envelope. The effect of the pore radius on the phase envelope is insignificant when the radius is very large. These results may become reference for future research and study. Keywords: Phase Behavior; Particle Swarm Optimization; Capillary Pressure; Reservoir Fluids; Phase Equilibrium; Phase Envelope.

  1. Understanding the effects of inter-particle contact friction on the elastic moduli of granular materials

    NARCIS (Netherlands)

    Taghizadeh Bajgirani, Kianoosh; Kumar, Nishant; Magnanimo, Vanessa; Luding, Stefan

    2015-01-01

    Understanding the mechanical stiffness of closely packed, dense granular systems is of interest in many fields, such as soil mechanics, material science and physics. The main difficulty arises due to discreteness and disorder in granular materials at the microscopic scale which requires a

  2. Understanding action control of parental support behavior for child physical activity.

    Science.gov (United States)

    Rhodes, Ryan E; Spence, John C; Berry, Tanya; Deshpande, Sameer; Faulkner, Guy; Latimer-Cheung, Amy E; O'Reilly, Norman; Tremblay, Mark S

    2016-02-01

    Parental support is the critical family-level variable linked to child physical activity (PA), yet the antecedents of support are poorly understood, and its relationship with intention is modest. The purpose of this study was to apply a framework designed to evaluate the intention-behavior gap, known as multiprocess action control (M-PAC), to understand parental support for regular child PA. Mothers (N = 1,253) with children 5-12 years of age completed measures of attitudes, perceived control over support, behavioral regulation tactics (e.g., planning, self-monitoring), and intention to support. Over half (58%) reported on subsequent support behaviors 6 months later. Three intention-behavior profiles emerged: (a) nonintenders (26.4%; n = 331), (b) unsuccessful intenders (36.6%; n = 458), and (c) successful intenders (33%; n = 414). Congruent with M-PAC, a discriminant function analysis showed that affective attitude about support (r = .18), perceived behavioral control over support (r = .55), and behavioral regulation (r = .55) distinguished between all 3 intention-behavior profiles. A disaggregated analysis of specific behavioral regulation tactics showed that most distinguished all 3 profiles, yet planning, information seeking, and monitoring were the critical correlates of the discriminant function. The majority of mothers had positive intentions to support regular child PA, yet over half failed to enact this support. Difficulty of intention translating into support behavior arises from compromised control over support, self-regulation skills, and perceptions that the support experience is unenjoyable. Interventions aimed at strengthening these factors are recommended to improve parental support action control. (c) 2016 APA, all rights reserved).

  3. Expanding the Understanding of Risk Behavior Associated With Homelessness Among Veterans.

    Science.gov (United States)

    Harris, Taylor; Kintzle, Sara; Wenzel, Suzanne; Castro, Carl Andrew

    2017-09-01

    To advance large-scale efforts to end veteran homelessness, an understanding of factors that contribute to housing insecurity is necessary. Common risk behaviors (e.g., substance use and risky sexual practices) are associated with lengthier experiences of homelessness among the general homeless population, but less understood among homeless veterans. Additionally, whether emerging risk behaviors among veterans (e.g., sensation seeking and aggression) are associated with lengthy homeless experiences is unknown. Data were drawn from a sample of Los Angeles County veterans surveyed using a mixed nonprobability sampling strategy, which included recruiting veterans via national and local veterans service organizations, college organizations, and social media campaigns. Measures aligning with factors of sensation seeking (reckless driving, gambling, suicidal ideation); substance use (alcohol misuse, tobacco use, driving while intoxicated); risky sexual practices (risking getting a sexually transmitted disease); and aggression (looking to start a fight) were tested in multivariate, multinomial logistic regression analyses to determine their association with varying lengths of homelessness in the past year (less than 1 month, 2-6 months, 6 months to 1 year). Risking getting a sexually transmitted disease, gambling, suicidal ideation, alcohol misuse, tobacco use, driving while intoxicated, and looking to start a fight were associated with 6 or more months of homelessness. Several indicators of risk were associated with brief periods of homelessness, including gambling and looking to start a fight. Although a clear exposure-response effect was not detected with risk behaviors, results suggested there may be some wavering of engagement in risk behaviors over time. Findings suggest sensation seeking and aggression risk behaviors should be included in risk assessments and prevention efforts along with substance use and risky sexual practices to reduce veterans' risk of becoming

  4. Improved understanding of the ball-pen probe through particle-in-cell simulations

    Science.gov (United States)

    Murphy-Sugrue, S.; Harrison, J.; Walkden, N. R.; Bryant, P.; Bradley, J. W.

    2017-05-01

    Ball-pen probes (BPP) have been deployed in the SOL of numerous tokamak experiments and low-temperature magnetised plasmas to make direct measurements of the plasma potential and electron temperature. Despite strong empirical evidence for the success of the BPP it lacks a theoretical underpinning of its collection mechanism. In this paper we investigate the capability of the probe to measure the plasma potential by means of particle-in-cell simulations. The BPP is found to float at a potential offset from the plasma potential by a factor {T}{{e}}{α }{{BPP}}. By simulating BPPs and Langmuir probes, excellent agreement has been found between the measured electron temperature and the specified source temperature. The transport mechanism for both ions and electrons has been determined. E × B drifts are observed to drive electrons and ions down the tunnel. This mechanism is sensitive to the diameter of the probe.

  5. Smoking cessation: an application of theory of planned behavior to understanding progress through stages of change.

    Science.gov (United States)

    Bledsoe, Linda K

    2006-07-01

    The purpose of this research was to investigate variables relevant to smoking cessation early in the process of change through an application of the Theory of Planned Behavior [Ajzen, I. (1985). From intentions to actions: A theory of planned behavior. In J. Kuhl and J. Beckman (Eds). Action-control: From cognition to behavior (pp.11-39). Heidelberg: Springer.] to the temporal structure provided by the Transtheoretical Model. Study 1 was a preliminary elicitation study (n=68) conducted to ground the concepts used in the model testing in Study 2 [Ajzen, I., Fishbein, M. (1980). Understanding attitudes and predicting social behavior, Englewood Cliffs, NJ: Prentice-Hall.]. Study 2 tested the proposed model fit with data from a sample of 230 adult smokers. Structural equation modeling did not support the Theory of Planned Behavior as a model of motivation for progress through the stages of change and highlighted measurement issues with perceived behavioral control. A modified model using the Theory of Reasoned Action provided a good fit to the data, accounting for approximately 64% of the variance in intention to quit smoking and stage of change. This research addresses the need for a more complete theoretical rationale for progress through stages of change.

  6. Copy of Using Emulation and Simulation to Understand the Large-Scale Behavior of the Internet.

    Energy Technology Data Exchange (ETDEWEB)

    Adalsteinsson, Helgi; Armstrong, Robert C.; Chiang, Ken; Gentile, Ann C.; Lloyd, Levi; Minnich, Ronald G.; Vanderveen, Keith; Van Randwyk, Jamie A; Rudish, Don W.

    2008-10-01

    We report on the work done in the late-start LDRDUsing Emulation and Simulation toUnderstand the Large-Scale Behavior of the Internet. We describe the creation of a researchplatform that emulates many thousands of machines to be used for the study of large-scale inter-net behavior. We describe a proof-of-concept simple attack we performed in this environment.We describe the successful capture of a Storm bot and, from the study of the bot and furtherliterature search, establish large-scale aspects we seek to understand via emulation of Storm onour research platform in possible follow-on work. Finally, we discuss possible future work.3

  7. Understanding nature's particle accelerators using high energy gamma-ray survey instruments

    Science.gov (United States)

    Abeysekara, Anushka Udara

    Nature's particle accelerators, such as Pulsars, Pulsar Wind Nebulae, Active Galactic Nuclei and Supernova Remnants accelerate charged particles to very high energies that then produce high energy photons. The particle acceleration mechanisms and the high energy photon emission mechanisms are poorly understood phenomena. These mechanisms can be understood either by studying individual sources in detail or, alternatively, using the collective properties of a sample of sources. Recent development of GeV survey instruments, such as Fermi-LAT, and TeV survey instruments, such as Milagro, provides a large sample of high energy gamma-ray flux measurements from galactic and extra-galactic sources. In this thesis I provide constraints on GeV and TeV radiation mechanisms using the X-ray-TeV correlations and GeV-TeV correlations. My data sample was obtained from three targeted searches for extragalactic sources and two targeted search for galactic sources, using the existing Milagro sky maps. The first extragalactic candidate list consists of Fermi-LAT GeV extragalactic sources, and the second extragalactic candidate list consists of TeVCat extragalactic sources that have been detected by Imaging Atmospheric Cerenkov Telescopes (IACTs). In both extragalactic candidate lists Markarian 421 was the only source detected by Milagro. A comparison between the Markarian 421 time-averaged flux, measured by Milagro, and the flux measurements of transient states, measured by IACTs, is discussed. The third extragalactic candidate list is a list of potential TeV emitting BL Lac candidates that was synthesized using X-ray observations of BL Lac objects and a Synchrotron Self-Compton model. Milagro's sensitivity was not sufficient to detect any of those candidates. However, the 95% confidence flux upper limits of those sources were above the predicted flux. Therefore, these results provide evidence to conclude that the Synchrotron Self-Compton model for BL Lac objects is still a viable

  8. Understanding Information Seeking Behavior of Indonesian Postgraduate Students in Malaysian Universities: An Empirical Study

    OpenAIRE

    Muhammad Subhan; Ahmad Bashawir Abdul Ghani

    2013-01-01

    Abstract : This study investigates Indonesian postgraduate student’s experience at the pre-sessional program of the process of seeking information and the strategies they used throughout the process. The objective is to understand their information seeking behavior particularly academic-related information in order to improve the effectiveness of educational communication in Malaysia higher institutions. Two research questions are addressed: what experiences do pre-sessional students face i...

  9. New GOES High-Resolution Magnetic Measurements and their Contribution to Understanding Magnetospheric Particle Dynamics

    Science.gov (United States)

    Redmon, R. J.; Loto'aniu, P. T. M.; Boudouridis, A.; Chi, P. J.; Singer, H. J.; Kress, B. T.; Rodriguez, J. V.; Abdelqader, A.; Tilton, M.

    2017-12-01

    studies, we find that the wave amplitude of poloidal oscillations is amplified at low altitudes but attenuated on the ground, confirming the theoretical predictions of wave propagation from the magnetosphere to the ground. We include examples of GOES-16 particle flux and magnetic field observations illustrating complex particle dynamics.

  10. The contributions of cognitive neuroscience and neuroimaging to understanding mechanisms of behavior change in addiction.

    Science.gov (United States)

    Morgenstern, Jon; Naqvi, Nasir H; Debellis, Robert; Breiter, Hans C

    2013-06-01

    In the last decade, there has been an upsurge of interest in understanding the mechanisms of behavior change (MOBC) and effective behavioral interventions as a strategy to improve addiction-treatment efficacy. However, there remains considerable uncertainty about how treatment research should proceed to address the MOBC issue. In this article, we argue that limitations in the underlying models of addiction that inform behavioral treatment pose an obstacle to elucidating MOBC. We consider how advances in the cognitive neuroscience of addiction offer an alternative conceptual and methodological approach to studying the psychological processes that characterize addiction, and how such advances could inform treatment process research. In addition, we review neuroimaging studies that have tested aspects of neurocognitive theories as a strategy to inform addiction therapies and discuss future directions for transdisciplinary collaborations across cognitive neuroscience and MOBC research. 2013 APA, all rights reserved

  11. Getting angry matters: Going beyond perspective taking and empathic concern to understand bystanders' behavior in bullying.

    Science.gov (United States)

    Pozzoli, Tiziana; Gini, Gianluca; Thornberg, Robert

    2017-12-01

    The present study examined the relations between different empathic dimensions and bystanders' behavior in bullying. Specifically, the indirect effects of empathic concern and perspective taking via empathic anger on defending and passive bystanding were tested in a sample of Italian young adolescents (N = 398; M age  = 12 years, 3 months, 47.2% girls). Path analysis confirmed the direct and indirect effects, via empathic anger, of empathic concern and perspective taking on bystanders' behavior, with the exception of the direct association between perspective taking and passive bystanding that was not significant. Our findings suggest that considering empathic anger together with empathic concern and perspective taking could help researchers to better understand the links between empathic dispositions and bystanders' behavior in bullying. Copyright © 2017. Published by Elsevier Ltd.

  12. Understanding behavioral intent to participate in shared decision-making in medically uncertain situations.

    Science.gov (United States)

    Maffei, Roxana M; Dunn, K; Zhang, J; Hsu, C E; Holmes, J H

    2012-01-01

    This article describes the process undertaken to identify and validate behavioral and normative beliefs and behavioral intent based on the Theory of Reasoned Action (TRA) and applied to men between the ages of 45 and 70 in the context of their participation in shared decision-making (SDM) in medically uncertain situations. This article also discusses the preliminary results of the aforementioned processes and explores potential future uses of this information that may facilitate greater understanding, efficiency and effectiveness of clinician-patient consultations. Twenty-five male subjects from the Philadelphia community participated in this study. Individual semi-structure patient interviews were conducted until data saturation was reached. Based on their review of the patient interview transcripts, researchers conducted a qualitative content analysis to identify prevalent themes and, subsequently, create a category framework. Qualitative indicators were used to evaluate respondents' experiences, beliefs, and behavioral intent relative to participation in shared decision-making during medical uncertainty. Based on the themes uncovered through the content analysis, a category framework was developed to facilitate understanding and increase the accuracy of predictions related to an individual's behavioral intent to participate in shared decision-making in medical uncertainty. The emerged themes included past experience with medical uncertainty, individual personality, and the relationship between the patient and his physician. The resulting three main framework categories include 1) an individual's Foundation for the concept of medical uncertainty, 2) how the individual Copes with medical uncertainty, and 3) the individual's Behavioral Intent to seek information and participate in shared decision-making during times of medically uncertain situations. The theme of Coping (with uncertainty) emerged as a particularly critical behavior/characteristic amongst the

  13. Hygroscopic behavior of substrate-deposited particles studied by micro-FT-IR spectroscopy and complementary methods of particle analysis.

    Science.gov (United States)

    Liu, Yong; Yang, Zhiwei; Desyaterik, Yury; Gassman, Paul L; Wang, Hai; Laskin, Alexander

    2008-02-01

    The application of microscopic Fourier transform infrared (micro-FT-IR) spectroscopy combined with complementary methods of particle analysis is demonstrated here for investigations of phase transitions and hygroscopic growth of micron-sized particles. The approach utilizes the exposure of substrate-deposited, isolated particles to humidified nitrogen inside a sample cell followed by micro-FT-IR spectroscopy over a selected sample area. Phase transitions of NaCl, sea salt, NaNO3, and (NH4)2SO4 particles are monitored with this technique to evaluate its utility and applicability for particle hydration studies. The results are found in excellent agreement with literature data in terms of (a) reliable and reproducible detection of deliquescence and efflorescence phase transitions, (b) quantitative measurements of water-to-solute ratios in particles as a function of relative humidity, and (c) changes in the IR spectra resulting from phase transitions and changing relative humidity. Additional methods of particle analysis are employed to complement and assist in the interpretation of particle hygroscopicity data obtained from micro-FT-IR measurements. The analytical approach and the experimental setup presented here are relatively simple, inexpensive, readily available and therefore may be practical for hydration studies of environmental particles collected in both laboratory and field studies.

  14. Understanding mild acid pretreatment of sugarcane bagasse through particle scale modeling.

    Science.gov (United States)

    Greenwood, Ava A; Farrell, Troy W; O'Hara, Ian M

    2013-12-01

    Sugarcane bagasse is an abundant and sustainable resource, generated as a by-product of sugarcane milling. The cellulosic material within bagasse can be broken down into glucose molecules and fermented to produce ethanol, making it a promising feedstock for biofuel production. Mild acid pretreatment hydrolyses the hemicellulosic component of biomass, thus allowing enzymes greater access to the cellulosic substrate during saccharification. A particle-scale mathematical model describing the mild acid pretreatment of sugarcane bagasse has been developed, using a volume averaged framework. Discrete population-balance equations are used to characterise the polymer degradation kinetics, and diffusive effects account for mass transport within the cell wall of the bagasse. As the fibrous material hydrolyses over time, variations in the porosity of the cell wall and the downstream effects on the reaction kinetics are accounted for using conservation of volume arguments. Non-dimensionalization of the model equations reduces the number of parameters in the system to a set of four dimensionless ratios that compare the timescales of different reaction and diffusion events. Theoretical yield curves are compared to macroscopic experimental observations from the literature and inferences are made as to constraints on these "unknown" parameters. These results enable connections to be made between experimental data and the underlying thermodynamics of acid pretreatment. Consequently, the results suggest that data-fitting techniques used to obtain kinetic parameters should be carefully applied, with prudent consideration given to the chemical and physiological processes being modeled. © 2013 Wiley Periodicals, Inc.

  15. Solar energetic particles a modern primer on understanding sources, acceleration and propagation

    CERN Document Server

    Reames, Donald V

    2017-01-01

    This concise primer introduces the non-specialist reader to the physics of solar energetic particles (SEP) and systematically reviews the evidence for the two main mechanisms which lead to the so-called impulsive and gradual SEP events. More specifically, the timing of the onsets, the longitude distributions, the high-energy spectral shapes, the correlations with other solar phenomena (e.g. coronal mass ejections), as well as the all-important elemental and isotopic abundances of SEPs are investigated. Impulsive SEP events are related to magnetic reconnection in solar flares and jets. The concept of shock acceleration by scattering on self-amplified Alfvén waves is introduced, as is the evidence of reacceleration of impulsive-SEP material in the seed population accessed by the shocks in gradual events. The text then develops processes of transport of ions out to an observer. Finally, a new technique to determine the source plasma temperature in both impulsive and gradual events is demonstrated. Last but not ...

  16. Contribution to the Understanding of Particle Motion Perception in Marine Invertebrates.

    Science.gov (United States)

    André, Michel; Kaifu, Kenzo; Solé, Marta; van der Schaar, Mike; Akamatsu, Tomonari; Balastegui, Andreu; Sánchez, Antonio M; Castell, Joan V

    2016-01-01

    Marine invertebrates potentially represent a group of species whose ecology may be influenced by artificial noise. Exposure to anthropogenic sound sources could have a direct consequence on the functionality and sensitivity of their sensory organs, the statocysts, which are responsible for their equilibrium and movements in the water column. The availability of novel laser Doppler vibrometer techniques has recently opened the possibility of measuring whole body (distance, velocity, and acceleration) vibration as a direct stimulus eliciting statocyst response, offering the scientific community a new level of understanding of the marine invertebrate hearing mechanism.

  17. High temperature oxidation behavior of SiC coating in TRISO coated particles

    International Nuclear Information System (INIS)

    Liu, Rongzheng; Liu, Bing; Zhang, Kaihong; Liu, Malin; Shao, Youlin; Tang, Chunhe

    2014-01-01

    Highlights: • High temperature oxidation tests of SiC coating in TRISO particles were carried out. • The dynamic oxidation process was established. • Oxidation mechanisms were proposed. • The existence of silicon oxycarbides at the SiO 2 /SiC interface was demonstrated. • Carbon was detected at the interface at high temperatures and long oxidation time. - Abstract: High temperature oxidation behavior of SiC coatings in tristructural-isotropic (TRISO) coated particles is crucial to the in-pile safety of fuel particles for a high temperature gas cooled reactor (HTGR). The postulated accident condition of air ingress was taken into account in evaluating the reliability of the SiC layer. Oxidation tests of SiC coatings were carried out in the ranges of temperature between 800 and 1600 °C and time between 1 and 48 h in air atmosphere. Based on the microstructure evolution of the oxide layer, the mechanisms and kinetics of the oxidation process were proposed. The existence of silicon oxycarbides (SiO x C y ) at the SiO 2 /SiC interface was demonstrated by X-ray photospectroscopy (XPS) analysis. Carbon was detected by Raman spectroscopy at the interface under conditions of very high temperatures and long oxidation time. From oxidation kinetics calculation, activation energies were 145 kJ/mol and 352 kJ/mol for the temperature ranges of 1200–1500 °C and 1550–1600 °C, respectively

  18. Influence of Boron on the Creep Behavior and the Microstructure of Particle Reinforced Aluminum Matrix Composites

    Directory of Open Access Journals (Sweden)

    Steve Siebeck

    2018-02-01

    Full Text Available The reinforcement of aluminum alloys with particles leads to the enhancement of their mechanical properties at room temperature. However, the creep behavior at elevated temperatures is often negatively influenced. This raises the question of how it is possible to influence the creep behavior of this type of material. Within this paper, selected creep and tensile tests demonstrate the beneficial effects of boron on the properties of precipitation-hardenable aluminum matrix composites (AMCs. The focus is on the underlying microstructure behind this effect. For this purpose, boron was added to AMCs by means of mechanical alloying. Comparatively higher boron contents than in steel are investigated in order to be able to record their influence on the microstructure including the formation of potential new phases as well as possible. While the newly formed phase Al3BC can be reliably detected by X-ray diffraction (XRD, it is difficult to obtain information about the phase distribution by means of scanning electron microscopy (SEM and scanning transmission electron microscopy (STEM investigations. An important contribution to this is finally provided by the investigation using Raman microscopy. Thus, the homogeneous distribution of finely scaled Al3BC particles is detectable, which allows conclusions about the microstructure/property relationship.

  19. Understanding action control of daily walking behavior among dog owners: a community survey.

    Science.gov (United States)

    Rhodes, Ryan E; Lim, Clarise

    2016-11-16

    Walking among dog owners may be a means to achieve health benefits, yet almost half of owners (approximately 30% of households) are not regularly walking their dogs. Current research on the correlates of dog walking has generally considered intention as the primary determinant of behavior, yet the intention-behavior relationship is modest. The purpose of this paper was to apply a framework designed to evaluate the intention-behavior gap, known as multi-process action control (M-PAC), to understand daily walking among dog owners. A community sample of adult dog owners (N = 227) in Victoria, Canada completed M-PAC measures of motivational (dog and human outcome expectations, affective judgments, perceived capability and opportunity), regulatory (planning), and reflexive (automaticity, identity) processes as well as intention to walk and behavior. Three intention-behavior profiles emerged: a) non-intenders who were not active (26%; n = 59), b) unsuccessful intenders who failed to enact their positive intentions (33%; n = 75), and c) successful intenders who were active (40%; n = 91). Congruent with M-PAC, a discriminant function analysis showed that affective judgements (r = 0.33), automaticity (r = 0.38), and planning (r = 0.33) distinguished between all three intention-behavior profiles, while identity (r = 0.22) and dog breed size (r = 0.28) differentiated between successful and unsuccessful intenders. The majority of dog owners have positive intentions to walk, yet almost half fail to meet these intentions. Interventions focused on affective judgments (e.g., more enjoyable places to walk), behavioral regulation (e.g., setting a concrete plan), habit (e.g., making routines and cues) and identity formation (e.g., affirmations of commitment) may help overcome difficulties with translating these intentions into action, thus increasing overall levels of walking.

  20. Understanding action control of daily walking behavior among dog owners: a community survey

    Directory of Open Access Journals (Sweden)

    Ryan E. Rhodes

    2016-11-01

    Full Text Available Abstract Background Walking among dog owners may be a means to achieve health benefits, yet almost half of owners (approximately 30% of households are not regularly walking their dogs. Current research on the correlates of dog walking has generally considered intention as the primary determinant of behavior, yet the intention-behavior relationship is modest. The purpose of this paper was to apply a framework designed to evaluate the intention-behavior gap, known as multi-process action control (M-PAC, to understand daily walking among dog owners. Method A community sample of adult dog owners (N = 227 in Victoria, Canada completed M-PAC measures of motivational (dog and human outcome expectations, affective judgments, perceived capability and opportunity, regulatory (planning, and reflexive (automaticity, identity processes as well as intention to walk and behavior. Results Three intention-behavior profiles emerged: a non-intenders who were not active (26%; n = 59, b unsuccessful intenders who failed to enact their positive intentions (33%; n = 75, and c successful intenders who were active (40%; n = 91. Congruent with M-PAC, a discriminant function analysis showed that affective judgements (r = 0.33, automaticity (r = 0.38, and planning (r = 0.33 distinguished between all three intention-behavior profiles, while identity (r = 0.22 and dog breed size (r = 0.28 differentiated between successful and unsuccessful intenders. Conclusions The majority of dog owners have positive intentions to walk, yet almost half fail to meet these intentions. Interventions focused on affective judgments (e.g., more enjoyable places to walk, behavioral regulation (e.g., setting a concrete plan, habit (e.g., making routines and cues and identity formation (e.g., affirmations of commitment may help overcome difficulties with translating these intentions into action, thus increasing overall levels of walking.

  1. Study of Substrate Preheating on Flattening Behavior of Thermal-Sprayed Copper Particles

    Science.gov (United States)

    Yang, K.; Fukumoto, M.; Yasui, T.; Yamada, M.

    2010-12-01

    In this study, the effect of substrate preheating on flattening behavior of thermal-sprayed particles was systematically investigated. A part of mirror-polished AISI304 substrates were preheated to 573 and 773 K for 10 min, and then exposed to an air atmosphere for different durations of up to 48 h, respectively. Contact angle of water droplet was measured on the substrate under designated conditions. It was found that the contact angle increased gradually with the increase of substrate duration after preheating. Moreover, smaller contact angle was maintained on the substrate with higher preheating temperature. Commercially available Cu powders were thermally sprayed onto the substrates with the same thermal treatment history as contact angle measurement using atmospheric plasma-spray technique. The splat shape had a transitional changing tendency from a splash splat to a disk one on the substrate with a short duration after preheating, while reappearance of splash splat with the increase of duration was confirmed. In general, wetting of substrate surface by molten particles may dominate the flattening behavior of thermal-sprayed particles. The occurrence of desorption of adsorbed gas/condensation caused by substrate preheating likely provides good wetting. On the other hand, the poor wetting may be attributed to the re-adsorption of gas/condensation on the substrate surface with the increase of duration. In addition, the shear adhesion strength of coating fabricated on blasted AISI304 substrate was enhanced on the once-heated substrate, but weakened with the increase of duration. The changing tendency of the coating adhesion strength and the wetting of substrate by droplet corresponded quite well with each other.

  2. Putting the Mind in the Brain: Promoting an Appreciation of the Biological Basis to Understanding Human Behavior

    Science.gov (United States)

    Neumann, David L.

    2010-01-01

    A surprising number of students in psychology, behavioral science, and related social science classes fail to appreciate the importance of biological mechanisms to understanding behavior. To help teachers promote this understanding, this paper outlines six sources of evidence. These are (a) phylogenetic, (b) genetic/developmental, (c) clinical,…

  3. MD Simulation on Collision Behavior Between Nano-Scale TiO₂ Particles During Vacuum Cold Spraying.

    Science.gov (United States)

    Yao, Hai-Long; Yang, Guan-Jun; Li, Chang-Jiu

    2018-04-01

    Particle collision behavior influences significantly inter-nano particle bonding formation during the nano-ceramic coating deposition by vacuum cold spraying (or aerosol deposition method). In order to illuminate the collision behavior between nano-scale ceramic particles, molecular dynamic simulation was applied to explore impact process between nano-scale TiO2 particles through controlling impact velocities. Results show that the recoil efficiency of the nano-scale TiO2 particle is decreased with the increase of the impact velocity. Nano-scale TiO2 particle exhibits localized plastic deformation during collision at low velocities, while it is intensively deformed by collision at high velocities. This intensive deformation promotes the nano-particle adhesion rather than rebounding off. A relationship between the adhesion energy and the rebound energy is established for the bonding formation of the nano-scale TiO2 particle. The adhesion energy required to the bonding formation between nano-scale ceramic particles can be produced by high velocity collision.

  4. On the Importance of Comparative Research for the Understanding of Human Behavior and Development: A Reply to Gottlieb & Lickliter (2004)

    Science.gov (United States)

    Maestripieri, Dario

    2005-01-01

    Comparative behavioral research is important for a number of reasons and can contribute to the understanding of human behavior and development in many different ways. Research with animal models of human behavior and development can be a source not only of general principles and testable hypotheses but also of empirical information that may be…

  5. Momentum Probabilities for a Single Quantum Particle in Three-Dimensional Regular "Infinite" Wells: One Way of Promoting Understanding of Probability Densities

    Science.gov (United States)

    Riggs, Peter J.

    2013-01-01

    Students often wrestle unsuccessfully with the task of correctly calculating momentum probability densities and have difficulty in understanding their interpretation. In the case of a particle in an "infinite" potential well, its momentum can take values that are not just those corresponding to the particle's quantised energies but…

  6. Understanding HIV Risk Behavior among Tuberculosis Patients with Alcohol Use Disorders in Tomsk, Russian Federation.

    Science.gov (United States)

    Miller, Ann C; Nelson, A Katrina; Livchits, Viktoria; Greenfield, Shelly F; Yanova, Galina; Yanov, Sergei; Connery, Hilary S; Atwood, Sidney; Lastimoso, Charmaine S; Shin, Sonya S

    2016-01-01

    Russian Federation's (RF) HIV epidemic is the fastest growing of any country. This study explores factors associated with high HIV risk behavior in tuberculosis (TB) patients with alcohol use disorders in Tomsk, RF. This analysis was nested within the Integrated Management of Physician-delivered Alcohol Care for TB Patients (IMPACT, trial number NCT00675961) randomized controlled study of integrating alcohol treatment into TB treatment in Tomsk. Demographics, HIV risk behavior (defined as participant report of high-risk intravenous drug use and/or multiple sexual partners with inconsistent condom use in the last six months), clinical data, alcohol use, depression and psychosocial factors were collected from 196 participants (161 male and 35 female) at baseline. Forty-six participants (23.5%) endorsed HIV risk behavior at baseline. Incarceration history(Odds Ratio (OR)3.93, 95% confidence interval (CI) 1.95, 7.95), age under 41 (OR:2.97, CI:1.46, 6.04), drug addiction(OR: 3.60 CI:1.10, 11.77), history of a sexually transmitted disease(STD)(OR 2.00 CI:1.02, 3.90), low social capital (OR:2.81 CI:0.99, 8.03) and heavier alcohol use (OR:2.56 CI: 1.02, 6.46) were significantly more likely to be associated with HIV risk behavior at baseline. In adjusted analysis, age under 41(OR: 4.93, CI: 2.10, 11.58), incarceration history(OR: 3.56 CI:1.55, 8.17) and STD history (OR: 3.48, CI: 1.5, 8.10) continued to be significantly associated with HIV risk behavior. Understanding HIV transmission dynamics in Russia remains an urgent priority to inform strategies to address the epidemic. Larger studies addressing sex differences in risks and barriers to protective behavior are needed.

  7. Understanding HIV Risk Behavior among Tuberculosis Patients with Alcohol Use Disorders in Tomsk, Russian Federation.

    Directory of Open Access Journals (Sweden)

    Ann C Miller

    Full Text Available Russian Federation's (RF HIV epidemic is the fastest growing of any country. This study explores factors associated with high HIV risk behavior in tuberculosis (TB patients with alcohol use disorders in Tomsk, RF. This analysis was nested within the Integrated Management of Physician-delivered Alcohol Care for TB Patients (IMPACT, trial number NCT00675961 randomized controlled study of integrating alcohol treatment into TB treatment in Tomsk. Demographics, HIV risk behavior (defined as participant report of high-risk intravenous drug use and/or multiple sexual partners with inconsistent condom use in the last six months, clinical data, alcohol use, depression and psychosocial factors were collected from 196 participants (161 male and 35 female at baseline. Forty-six participants (23.5% endorsed HIV risk behavior at baseline. Incarceration history(Odds Ratio (OR3.93, 95% confidence interval (CI 1.95, 7.95, age under 41 (OR:2.97, CI:1.46, 6.04, drug addiction(OR: 3.60 CI:1.10, 11.77, history of a sexually transmitted disease(STD(OR 2.00 CI:1.02, 3.90, low social capital (OR:2.81 CI:0.99, 8.03 and heavier alcohol use (OR:2.56 CI: 1.02, 6.46 were significantly more likely to be associated with HIV risk behavior at baseline. In adjusted analysis, age under 41(OR: 4.93, CI: 2.10, 11.58, incarceration history(OR: 3.56 CI:1.55, 8.17 and STD history (OR: 3.48, CI: 1.5, 8.10 continued to be significantly associated with HIV risk behavior. Understanding HIV transmission dynamics in Russia remains an urgent priority to inform strategies to address the epidemic. Larger studies addressing sex differences in risks and barriers to protective behavior are needed.

  8. UNDERSTANDING OF NON VERBAL BEHAVIOR CLIENTS AND TECHNIQUES IN COUNSELING SESSION

    Directory of Open Access Journals (Sweden)

    afdal afdal

    2016-06-01

    Full Text Available The practice of counseling by counselor not only need the skills to understand what is expressed by the client, but were further able to understand and have skills in giving meaning to the nonverbal communication, demonstrated by the behavior of a counseling session. During this time many of counselors who focus only on what is revealed by the client and using verbal techniques alone without seeing what goes on inside the client more deeply to understand the communication indicated by nonverbal behavior. The techniques used in the discussion of this article provides the inspiration that counseling is an art, not superficial, not skeptical and just focus on one technique alone, but many of the techniques that can be used to explore client issues. Furthermore, this paper supports the philosophical theory of Gestalt who believe that the client can feel the direct presence in the counseling sessions through the practices of the techniques used, to interpret the expression of various communications made, stationing themselves and find their own meaning.

  9. Understanding professional behavior: experiences of occupational therapy students in mental health settings.

    Science.gov (United States)

    Lyons, M

    1997-09-01

    A phenomenological study explored occupational therapy students' experiences in psychiatric fieldwork. Of particular interest was students' understanding of professional behavior toward persons who use mental health services. Data were gathered from 16 informants via in-depth interviews and participant observation on multiple occasions during fieldwork affiliations. Emerging from informants' views of professional behavior were difficulties in their reconciling conflicting expectations with regard to emotional and social distance from persons who use mental health services. Additionally, the informants experienced a need to assume authority and maintain control in their dealings with service users. Students' encounters with such issues during fieldwork are indicative of challenges they may face as health professionals in a changing climate of mental health services. These data are stimuli for reflection on features of professional relationships with service users, particularly in response to expectations of persons with disabilities regarding control over their lives.

  10. Bridging the Gap: Towards a Cell-Type Specific Understanding of Neural Circuits Underlying Fear Behaviors

    Science.gov (United States)

    McCullough, KM; Morrison, FG; Ressler, KJ

    2016-01-01

    Fear and anxiety-related disorders are remarkably common and debilitating, and are often characterized by dysregulated fear responses. Rodent models of fear learning and memory have taken great strides towards elucidating the specific neuronal circuitries underlying the learning of fear responses. The present review addresses recent research utilizing optogenetic approaches to parse circuitries underlying fear behaviors. It also highlights the powerful advances made when optogenetic techniques are utilized in a genetically defined, cell-type specific, manner. The application of next-generation genetic and sequencing approaches in a cell-type specific context will be essential for a mechanistic understanding of the neural circuitry underlying fear behavior and for the rational design of targeted, circuit specific, pharmacologic interventions for the treatment and prevention of fear-related disorders. PMID:27470092

  11. Microstructure of Semi-Solid Billets Produced by Electromagnetic Stirring and Behavior of Primary Particles during the Indirect Forming Process

    Directory of Open Access Journals (Sweden)

    Chul Kyu Jin

    2018-04-01

    Full Text Available An A356 alloy semi-solid billet was fabricated using electromagnetic stirring. After inserting the semi-solid billet into an indirect die, a thin plate of 1.2 mm thickness was fabricated by applying compression. The microstructure of the semi-solid billets fabricated in various stirring conditions (solid fraction and stirring force were analyzed. The deformation and behavior of the primary α-Al particles were analyzed for various parameters (solid fraction, die friction, compression rate, and compression pressure. In the stirred billets, a globular structure was dominant, while a dendrite structure was dominant in the unstirred billets. As the solid fraction decreased and the stirring current increased, the equivalent diameter and roundness of the primary α-Al particles decreased. The primary α-Al particle sizes were reduced as the compressing velocity increased, while a greater number of particles could move as the compressing pressure increased. As the path over which the motion occurred became smoother, the fluidity of the particles improved. Under compression, bonded primary α-Al particles became separated into individual particles again, as the bonds were broken. As wearing caused by friction and collisions between the particles during this motion occurred, the particle sizes were reduced, and the particle shapes become increasingly spheroid.

  12. Human behavior understanding in networked sensing theory and applications of networks of sensors

    CERN Document Server

    Spagnolo, Paolo; Distante, Cosimo

    2014-01-01

    This unique text/reference provides a broad overview of both the technical challenges in sensor network development, and the real-world applications of distributed sensing. Important aspects of distributed computing in large-scale networked sensor systems are analyzed in the context of human behavior understanding, including such topics as systems design tools and techniques, in-network signals, and information processing. Additionally, the book examines a varied range of application scenarios, covering surveillance, indexing and retrieval, patient care, industrial safety, social and ambient

  13. #consumingitall: Understanding The Complex Relationship Between Media Consumption And Eating Behaviors

    OpenAIRE

    Albert, Stephanie L.

    2017-01-01

    Adolescents spend almost nine hours a day engaging with media. As a result, they are confronted with large amounts of obesogenic content that shapes their understanding of what are normal and acceptable eating behaviors. Utilizing primary data collected from a sample of 4,838 low-income, racially and ethnically diverse middle school students in Los Angeles County, I studied the effects of different types of media use (i.e., social media, TV/movies/videos, gaming, music, Internet) on dietary p...

  14. Nuclear planetology: understanding planetary mantle and crust formation in the light of nuclear and particle physics

    Science.gov (United States)

    Roller, Goetz

    2017-04-01

    The Hertzsprung-Russell (HR) diagram is one of the most important diagrams in astronomy. In a HR diagram, the luminosity of stars and/or stellar remnants (white dwarf stars, WD's), relative to the luminosity of the sun, is plotted versus their surface temperatures (Teff). The Earth shows a striking similarity in size (radius ≈ 6.371 km) and Teff of its outer core surface (Teff ≈ 3800 K at the core-mantle-boundary) with old WD's (radius ≈ 6.300 km) like WD0346+246 (Teff ≈ 3820 K after ≈ 12.7 Ga [1]), which plot in the HR diagram close to the low-mass extension of the stellar population or main sequence. In the light of nuclear planetology [2], Earth-like planets are regarded as old, down-cooled and differentiated black dwarfs (Fe-C BLD's) after massive decompression, the most important nuclear reactions involved being 56Fe(γ,α)52Cr (etc.), possibly responsible for extreme terrestrial glaciations events ("snowball" Earth), together with (γ,n), (γ,p) and fusion reactions like 12C(α,γ)16O. The latter reaction might have caused oxidation of the planet from inside out. Nuclear planetology is a new research field, tightly constrained by a coupled 187Re-232Th-238U systematics [3-5]. By means of nuclear/quantum physics and taking the theory of relativity into account, it aims at understanding the thermal and chemical evolution of Fe-C BLD's after gravitational contraction (e.g. Mercury) or Fermi-pressure controlled collapse (e.g. Earth) events after massive decompression, leading possibly to an r-process event, towards the end of their cooling period [2]. So far and based upon 187Re-232Th-238U nuclear geochronometry, the Fe-C BLD hypothesis can successfully explain the global terrestrial MORB 232Th/238U signature [5]. Thus, it may help to elucidate the DM (depleted mantle), EMI (enriched mantle 1), EMII (enriched mantle 2) or HIMU (high U/Pb) reservoirs [6], and the 187Os/188Os isotopic dichotomy in Archean magmatic rocks and sediments [7]. Here I present a

  15. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    Science.gov (United States)

    Asher, Lucy; Harvey, Naomi D.; Green, Martin; England, Gary C. W.

    2017-01-01

    Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between) a binary event(s) and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM) can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses), and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided. PMID:28804710

  16. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs

    Directory of Open Access Journals (Sweden)

    Lucy Asher

    2017-07-01

    Full Text Available Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between a binary event(s and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses, and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided.

  17. Toward a qualitative understanding of binge-watching behaviors: A focus group approach.

    Science.gov (United States)

    Flayelle, Maèva; Maurage, Pierre; Billieux, Joël

    2017-12-01

    Background and aims Binge-watching (i.e., seeing multiple episodes of the same TV series in a row) now constitutes a widespread phenomenon. However, little is known about the psychological factors underlying this behavior, as reflected by the paucity of available studies, most merely focusing on its potential harmfulness by applying the classic criteria used for other addictive disorders without exploring the uniqueness of binge-watching. This study thus aimed to take the opposite approach as a first step toward a genuine understanding of binge-watching behaviors through a qualitative analysis of the phenomenological characteristics of TV series watching. Methods A focus group of regular TV series viewers (N = 7) was established to explore a wide range of aspects related to TV series watching (e.g., motives, viewing practices, and related behaviors). Results A content analysis identified binge-watching features across three dimensions: TV series watching motivations, TV series watching engagement, and structural characteristics of TV shows. Most participants acknowledged that TV series watching can become addictive, but they all agreed having trouble recognizing themselves as truly being an "addict." Although obvious connections could be established with substance addiction criteria and symptoms, such parallelism appeared to be insufficient, as several distinctive facets emerged (e.g., positive view, transient overinvolvement, context dependency, and low everyday life impact). Discussion and conclusion The research should go beyond the classic biomedical and psychological models of addictive behaviors to account for binge-watching in order to explore its specificities and generate the first steps toward an adequate theoretical rationale for these emerging problematic behaviors.

  18. ISBP: Understanding the Security Rule of Users' Information-Sharing Behaviors in Partnership.

    Directory of Open Access Journals (Sweden)

    Hongchen Wu

    Full Text Available The rapid growth of social network data has given rise to high security awareness among users, especially when they exchange and share their personal information. However, because users have different feelings about sharing their information, they are often puzzled about who their partners for exchanging information can be and what information they can share. Is it possible to assist users in forming a partnership network in which they can exchange and share information with little worry? We propose a modified information sharing behavior prediction (ISBP model that can help in understanding the underlying rules by which users share their information with partners in light of three common aspects: what types of items users are likely to share, what characteristics of users make them likely to share information, and what features of users' sharing behavior are easy to predict. This model is applied with machine learning techniques in WEKA to predict users' decisions pertaining to information sharing behavior and form them into trustable partnership networks by learning their features. In the experiment section, by using two real-life datasets consisting of citizens' sharing behavior, we identify the effect of highly sensitive requests on sharing behavior adjacent to individual variables: the younger participants' partners are more difficult to predict than those of the older participants, whereas the partners of people who are not computer majors are easier to predict than those of people who are computer majors. Based on these findings, we believe that it is necessary and feasible to offer users personalized suggestions on information sharing decisions, and this is pioneering work that could benefit college researchers focusing on user-centric strategies and website owners who want to collect more user information without raising their privacy awareness or losing their trustworthiness.

  19. ISBP: Understanding the Security Rule of Users' Information-Sharing Behaviors in Partnership.

    Science.gov (United States)

    Wu, Hongchen; Wang, Xinjun

    2016-01-01

    The rapid growth of social network data has given rise to high security awareness among users, especially when they exchange and share their personal information. However, because users have different feelings about sharing their information, they are often puzzled about who their partners for exchanging information can be and what information they can share. Is it possible to assist users in forming a partnership network in which they can exchange and share information with little worry? We propose a modified information sharing behavior prediction (ISBP) model that can help in understanding the underlying rules by which users share their information with partners in light of three common aspects: what types of items users are likely to share, what characteristics of users make them likely to share information, and what features of users' sharing behavior are easy to predict. This model is applied with machine learning techniques in WEKA to predict users' decisions pertaining to information sharing behavior and form them into trustable partnership networks by learning their features. In the experiment section, by using two real-life datasets consisting of citizens' sharing behavior, we identify the effect of highly sensitive requests on sharing behavior adjacent to individual variables: the younger participants' partners are more difficult to predict than those of the older participants, whereas the partners of people who are not computer majors are easier to predict than those of people who are computer majors. Based on these findings, we believe that it is necessary and feasible to offer users personalized suggestions on information sharing decisions, and this is pioneering work that could benefit college researchers focusing on user-centric strategies and website owners who want to collect more user information without raising their privacy awareness or losing their trustworthiness.

  20. Application of Survival Analysis and Multistate Modeling to Understand Animal Behavior: Examples from Guide Dogs.

    Science.gov (United States)

    Asher, Lucy; Harvey, Naomi D; Green, Martin; England, Gary C W

    2017-01-01

    Epidemiology is the study of patterns of health-related states or events in populations. Statistical models developed for epidemiology could be usefully applied to behavioral states or events. The aim of this study is to present the application of epidemiological statistics to understand animal behavior where discrete outcomes are of interest, using data from guide dogs to illustrate. Specifically, survival analysis and multistate modeling are applied to data on guide dogs comparing dogs that completed training and qualified as a guide dog, to those that were withdrawn from the training program. Survival analysis allows the time to (or between) a binary event(s) and the probability of the event occurring at or beyond a specified time point. Survival analysis, using a Cox proportional hazards model, was used to examine the time taken to withdraw a dog from training. Sex, breed, and other factors affected time to withdrawal. Bitches were withdrawn faster than dogs, Labradors were withdrawn faster, and Labrador × Golden Retrievers slower, than Golden Retriever × Labradors; and dogs not bred by Guide Dogs were withdrawn faster than those bred by Guide Dogs. Multistate modeling (MSM) can be used as an extension of survival analysis to incorporate more than two discrete events or states. Multistate models were used to investigate transitions between states of training to qualification as a guide dog or behavioral withdrawal, and from qualification as a guide dog to behavioral withdrawal. Sex, breed (with purebred Labradors and Golden retrievers differing from F1 crosses), and bred by Guide Dogs or not, effected movements between states. We postulate that survival analysis and MSM could be applied to a wide range of behavioral data and key examples are provided.

  1. Effect of the powder particle size on the wear behavior of boronized AISI 304 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Guenen, Ali [Mustafa Kemal Univ., Hatay (Turkey). Dept. of Metallurgy and Material Engineering; Kuecuek, Yilmaz; Oege, Mecit; Goek, M. Sabri [Bartin Univ. (Turkey). Dept. of Mechanical Engineering; Er, Yusuf [Firat Univ., Elazig (Turkey); Cay, V. Veli [Dicle Univ., Diyarbakir (Turkey). Civil Aviation Higher School

    2015-06-01

    In this study, the AISI 304 steel specimens were boronized with nanoboron of the size of 10 50 nm and commercial Ekabor 3 powders (<1400 μm) at 950 C to 1000 C for 2 h and 4 h. Boronized steel specimens were characterized via SEM, microhardness and XRD analyses. Abrasive wear behavior of the specimens, boronized at different temperatures and treatment durations, were examined. The fixed ball micro-abrasion tests were carried out using the abrasive slurry, prepared with different SiC powder particle sizes on the boronized specimens at different rotational speeds. The specimens boronized with nanoboron powders exhibited a higher hardness and abrasive wear resistance than the samples boronized with the Ekabor 3 powders.

  2. The Dynamic Behavior of Water Flowing Through Packed Bed of Different Particle Shapes and Sizes

    Directory of Open Access Journals (Sweden)

    Haneen Ahmed Jasim

    2017-12-01

    Full Text Available An experimental study was conducted on pressure drop of water flow through vertical cylindrical packed beds in turbulent region and the influence of the operating parameters on its behavior. The bed packing was made of spherical and non-spherical particles (spheres, Rasching rings and intalox saddle with aspect ratio range 3.46 D/dp 8.486 obtaining bed porosities 0.396 0.84 and Reynolds number 1217 21758. The system is consisted of 5 cm inside diameter Perspex column, 50 cm long; distilled water was pumped through the bed with flow rate 875, 1000, 1125, 1250,1375 and 1500 l/h and inlet water temperature 20, 30, 40 and 50 ˚C. The packed bed system was monitored by using LabVIEW program, were the results have been obtained from Data Acquisition Adaptor (DAQ.

  3. Thermal and magnetic behavior of Angustifolia Kunth bamboo fibers covered with Fe3O4 particles

    International Nuclear Information System (INIS)

    Calvo, S.; Arias, N.P.; Giraldo, O.; Rosales-Rivera, A.; Moscoso, O.

    2012-01-01

    Several Angustifolia Kunth bamboo fibers, which have been previously treated with an alkaline solution, were coated with magnetite particles. The coating of the fibers was achieved by an in-situ co-precipitation method with Fe 2+ and Fe 3+ in NaOH or NH 4 OH. The fibers were evaluated by chemical analysis using atomic absorption (A.A.) technique, structural characterization by X-ray diffraction (XRD), thermal stability with thermo-gravimetric analysis (TGA) in nitrogen at temperature range between 23 °C and 800 °C and magnetic behavior using vibrating sample magnetometry (VSM) applying a magnetic field between -27 KOe and 27 KOe at room temperature. We found that the thermal stability and magnetization depend of the synthesis method used to cover the Angustifolia Kunth bamboo fibers. In addition, an improved magnetic response was observed when NaOH solution is used to generate the magnetite coating on the fiber surface.

  4. Understanding compressive deformation behavior of porous Ti using finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Sandipan; Khutia, Niloy [Department of Aerospace Engineering and Applied Mechanics, Indian Institute of Engineering Science and Technology, Shibpur (India); Das, Debdulal [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur (India); Das, Mitun, E-mail: mitun@cgcri.res.in [Bioceramics and Coating Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India); Balla, Vamsi Krishna [Bioceramics and Coating Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India); Bandyopadhyay, Amit [W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States); Chowdhury, Amit Roy, E-mail: arcbesu@gmail.com [Department of Aerospace Engineering and Applied Mechanics, Indian Institute of Engineering Science and Technology, Shibpur (India)

    2016-07-01

    In the present study, porous commercially pure (CP) Ti samples with different volume fraction of porosities were fabricated using a commercial additive manufacturing technique namely laser engineered net shaping (LENS™). Mechanical behavior of solid and porous samples was evaluated at room temperature under quasi-static compressive loading. Fracture surfaces of the failed samples were analyzed to determine the failure modes. Finite Element (FE) analysis using representative volume element (RVE) model and micro-computed tomography (CT) based model have been performed to understand the deformation behavior of laser deposited solid and porous CP-Ti samples. In vitro cell culture on laser processed porous CP-Ti surfaces showed normal cell proliferation with time, and confirmed non-toxic nature of these samples. - Highlights: • Porous CP-Ti samples fabricated using additive manufacturing technique • Compressive deformation behavior of porous samples closely matches with micro-CT and RVE based analysis • In vitro studies showed better cell proliferation with time on porous CP-Ti surfaces.

  5. Understanding why low-risk patients accept vaccines: a socio-behavioral approach.

    Science.gov (United States)

    Wiemken, Timothy L; Carrico, Ruth M; Kelley, Robert R; Binford, Laura E; Peyrani, Paula; Ford, Kimbal D; Welch, Verna; Ramirez, Julio A

    2015-12-23

    Vaccines are one of the most important public health interventions. Understanding factors associated with vaccine acceptance is critical. The objectives of this study were to evaluate the impact of the three constructs of the Theory of Planned Behavior (TPB) on the intention to be vaccinated among healthy individuals being seen for pre-travel care, and to evaluate if behavioral intention was associated with vaccine acceptance. We surveyed individuals seeking vaccination at the University of Louisville Vaccine and International Health and Travel Clinic. Linear and two stage least squares regression models were used to define the associations between constructs of the TPB and the intention to be vaccinated, as well as the association between the intention to be vaccinated and vaccine acceptance. A total of 183 individuals were included in the analysis. None of the constructs of the TPB were associated with intention to be vaccinated. Behavioral intention was not associated with vaccination acceptance. This study suggests that the TPB does not predict the intention to get vaccinated among individuals attending our Vaccine and International Health and Travel Clinic. It will be critical to define better predictors of vaccine uptake in healthy, low-risk individuals to increase vaccine acceptance.

  6. Understanding the effects of stress and alcohol cues on motivation for alcohol via behavioral economics.

    Science.gov (United States)

    Amlung, Michael; MacKillop, James

    2014-06-01

    Psychological stress and alcohol cues are common antecedents of both ongoing drinking and relapse. One candidate mechanism of risk from these factors is acute increases in craving, but experimental support for this hypothesis is mixed. Furthermore, the combination of stress and cues has been largely unstudied. The current study employed a behavioral economic approach to investigate the combined roles of psychosocial stress and alcohol cues on motivation for alcohol. In a sample of 84 adult heavy drinkers, we examined the effects of an acute laboratory stress induction and an alcohol cue exposure on subjective craving and stress, arousal, and behavioral economic decision making. Primary dependent measures included an intertemporal cross-commodity multiple-choice procedure (ICCMCP), incorporating both price and delay elements, an alcohol purchase task (APT), measuring alcohol demand, and a monetary delay discounting task, measuring intertemporal choice. The stress induction significantly increased stress, craving, and the incentive value of alcohol on the ICCMCP and APT. Stress-related increases in value on the ICCMCP were mediated by increased alcohol demand. Exposure to alcohol cues only significantly affected craving, APT breakpoint, and arousal. Delay discounting was not affected by either stress or cues. These results reveal unique behavioral economic dimensions of motivation for alcohol following acute stress and an alcohol cue exposure. More broadly, as the first application of this approach to understanding the role of stress in drug motivation, these findings support its utility and potential in future applications. Copyright © 2014 by the Research Society on Alcoholism.

  7. Understanding compressive deformation behavior of porous Ti using finite element analysis

    International Nuclear Information System (INIS)

    Roy, Sandipan; Khutia, Niloy; Das, Debdulal; Das, Mitun; Balla, Vamsi Krishna; Bandyopadhyay, Amit; Chowdhury, Amit Roy

    2016-01-01

    In the present study, porous commercially pure (CP) Ti samples with different volume fraction of porosities were fabricated using a commercial additive manufacturing technique namely laser engineered net shaping (LENS™). Mechanical behavior of solid and porous samples was evaluated at room temperature under quasi-static compressive loading. Fracture surfaces of the failed samples were analyzed to determine the failure modes. Finite Element (FE) analysis using representative volume element (RVE) model and micro-computed tomography (CT) based model have been performed to understand the deformation behavior of laser deposited solid and porous CP-Ti samples. In vitro cell culture on laser processed porous CP-Ti surfaces showed normal cell proliferation with time, and confirmed non-toxic nature of these samples. - Highlights: • Porous CP-Ti samples fabricated using additive manufacturing technique • Compressive deformation behavior of porous samples closely matches with micro-CT and RVE based analysis • In vitro studies showed better cell proliferation with time on porous CP-Ti surfaces

  8. Thermally sensitive block copolymer particles prepared via aerosol flow reactor method: Morphological characterization and behavior in water.

    Science.gov (United States)

    Nykänen, Antti; Rahikkala, Antti; Hirvonen, Sami-Pekka; Aseyev, Vladimir; Tenhu, Heikki; Mezzenga, Raffaele; Raula, Janne; Kauppinen, Esko; Ruokolainen, Janne

    2012-10-23

    This work describes properties of thermo-sensitive submicron sized particles having the same chemical composition but different morphologies. These particles have been prepared with an aerosol technique using dimethylformamide solutions of linear polystyrene-block-poly(N-isopropylacrylamide-block-polystyrene, PS-b-PNIPAM-b-PS. The particles were characterized by cryo-electron microscopy, microcalorimetry, and light scattering. Block-copolymers self-assembled within the particles forming onion-like, gyroid-like, and spherical morphologies having poly(N-isopropylacrylamide) matrix and physically cross-linking polystyrene domains. The particles were dispersed in aqueous media and their behavior in water was studied both below and above the lower critical solution temperature of poly(N-isopropylacrylamide). We found out that the particles with spherical and gyroid-like morphologies swell considerably in water at 20 °C, whereas at 40 °C the particles resemble more of those studied without water treatment. Light scattering experiments showed that the particles gradually aggregate and precipitate with time at 40 °C. Microcalorimetric studies revealed for all three studied morphologies that PNIPAM undergoes a two-step transition due to the different hydration levels of PNIPAM inside and outside the particles. Thicknesses of the PS and PNIPAM layers within the onion-like particles were analyzed using the TEM micrographs by fitting a model of electron density to the integrated electron intensity data. The surface layer of the particles was found out to be PNIPAM, which was supported by light scattering and microcalorimetry. It was also found out from the TEM micrograph analysis that the width of the outmost PS layer is considerably thinner than the one in the dry state prior to immersion in water, and a degradation scheme is proposed to explain these results.

  9. Coupling an aerosol box model with one-dimensional flow: a tool for understanding observations of new particle formation events

    OpenAIRE

    Kivekäs, N.; Carpman, J.; Roldin, P.; Leppä, J.; O'Connor, E. J.; Kristensson, A.; Asmi, E.

    2016-01-01

    Field observations of new particle formation and the subsequent particle growth are typically only possible at a fixed measurement location, and hence do not follow the temporal evolution of an air parcel in a Lagrangian sense. Standard analysis for determining formation and growth rates requires that the time-dependent formation rate and growth rate of the particles are spatially invariant; air parcel advection means that the observed temporal evolution of the particle size distribution at a...

  10. Applied Behavior Analysis, Autism, and Occupational Therapy: A Search for Understanding.

    Science.gov (United States)

    Welch, Christie D; Polatajko, H J

    2016-01-01

    Occupational therapists strive to be mindful, competent practitioners and continuously look for ways to improve practice. Applied behavior analysis (ABA) has strong evidence of effectiveness in helping people with autism achieve goals, yet it does not seem to be implemented in occupational therapy practice. To better understand whether ABA could be an evidence-based option to expand occupational therapy practice, the authors conducted an iterative, multiphase investigation of relevant literature. Findings suggest that occupational therapists apply developmental and sensory approaches to autism treatment. The occupational therapy literature does not reflect any use of ABA despite its strong evidence base. Occupational therapists may currently avoid using ABA principles because of a perception that ABA is not client centered. ABA principles and occupational therapy are compatible, and the two could work synergistically. Copyright © 2016 by the American Occupational Therapy Association, Inc.

  11. Understanding Information Seeking Behavior of Indonesian Postgraduate Students in Malaysian Universities: An Empirical Study

    Directory of Open Access Journals (Sweden)

    Muhammad Subhan

    2013-12-01

    Full Text Available Abstract : This study investigates Indonesian postgraduate student’s experience at the pre-sessional program of the process of seeking information and the strategies they used throughout the process. The objective is to understand their information seeking behavior particularly academic-related information in order to improve the effectiveness of educational communication in Malaysia higher institutions. Two research questions are addressed: what experiences do pre-sessional students face in the process of information seeking that can be articulated and described? What stages do pre-sessional students experience in the process of information seeking construction? Using the qualitative method, the study found that the pre-sessional students have different patterns in the constructive process of information seeking in two different groups i.e. writing and reading classes. Six stages and four stages of the search process were identified respectively for the two groups.

  12. Analysis of Online Social Networks to Understand Information Sharing Behaviors Through Social Cognitive Theory

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hong-Jun [ORNL; Tourassi, Georgia [ORNL

    2014-01-01

    Analyzing the contents of online social networks is an effective process for monitoring and understanding peoples behaviors. Since the nature of conversation and information propagation is similar to traditional conversation and learning, one of the popular socio-cognitive methods, social cognitive theory was applied to online social networks to. Two major news topics about colon cancer were chosen to monitor traffic of Twitter messages. The activity of leaders on the issue (i.e., news companies or people will prior Twitter activity on topics related to colon cancer) was monitored. In addition, the activity of followers , people who never discussed the topics before, but replied to the discussions was also monitored. Topics that produce tangible benefits such as positive outcomes from appropriate preventive actions received dramatically more attention and online social media traffic. Such characteristics can be explained with social cognitive theory and thus present opportunities for effective health campaigns.

  13. Analysis of Online Social Networks to Understand Information Sharing Behaviors Through Social Cognitive Theory.

    Science.gov (United States)

    Yoon, Hong-Jun; Tourassi, Georgia

    2014-05-01

    Analyzing the contents of online social networks is an effective process for monitoring and understanding peoples' behaviors. Since the nature of conversation and information propagation is similar to traditional conversation and learning, one of the popular socio-cognitive methods, social cognitive theory was applied to online social networks to. Two major news topics about colon cancer were chosen to monitor traffic of Twitter messages. The activity of "leaders" on the issue (i.e., news companies or people will prior Twitter activity on topics related to colon cancer) was monitored. In addition, the activity of "followers", people who never discussed the topics before, but replied to the discussions was also monitored. Topics that produce tangible benefits such as positive outcomes from appropriate preventive actions received dramatically more attention and online social media traffic. Such characteristics can be explained with social cognitive theory and thus present opportunities for effective health campaigns.

  14. Understanding social and behavioral drivers and impacts of air quality sensor use.

    Science.gov (United States)

    Hubbell, Bryan J; Kaufman, Amanda; Rivers, Louie; Schulte, Kayla; Hagler, Gayle; Clougherty, Jane; Cascio, Wayne; Costa, Dan

    2018-04-15

    Lower-cost air quality sensors (hundreds to thousands of dollars) are now available to individuals and communities. This technology is undergoing a rapid and fragmented evolution, resulting in sensors that have uncertain data quality, measure different air pollutants and possess a variety of design attributes. Why and how individuals and communities choose to use sensors is arguably influenced by social context. For example, community experiences with environmental exposures and health effects and related interactions with industry and government can affect trust in traditional air quality monitoring. To date, little social science research has been conducted to evaluate why or how sensors, and sensor data, are used by individuals and communities, or how the introduction of sensors changes the relationship between communities and air quality managers. This commentary uses a risk governance/responsible innovation framework to identify opportunities for interdisciplinary research that brings together social scientists with air quality researchers involved in developing, testing, and deploying sensors in communities. Potential areas for social science research include communities of sensor users; drivers for use of sensors and sensor data; behavioral, socio-political, and ethical implications of introducing sensors into communities; assessing methods for communicating sensor data; and harnessing crowdsourcing capabilities to analyze sensor data. Social sciences can enhance understanding of perceptions, attitudes, behaviors, and other human factors that drive levels of engagement with and trust in different types of air quality data. New transdisciplinary research bridging social sciences, natural sciences, engineering, and design fields of study, and involving citizen scientists working with professionals from a variety of backgrounds, can increase our understanding of air sensor technology use and its impacts on air quality and public health. Published by Elsevier B.V.

  15. Effect of Aerogel Particle Concentration on Mechanical Behavior of Impregnated RTV 655 Compound Material for Aerospace Applications

    Directory of Open Access Journals (Sweden)

    Firouzeh Sabri

    2014-01-01

    Full Text Available Aerogels are a unique class of materials with superior thermal and mechanical properties particularly suitable for insulating and cryogenic storage applications. It is possible to overcome geometrical restrictions imposed by the rigidity of monolithic polyurea cross-linked silica aerogels by encapsulating micrometer-sized particles in a chemically resistant thermally insulating elastomeric “sleeve.” The ultimate limiting factor for the compound material’s performance is the effect of aerogel particles on the mechanical behavior of the compound material which needs to be fully characterized. The effect of size and concentration of aerogel microparticles on the tensile behavior of aerogel impregnated RTV655 samples was explored both at room temperature and at 77 K. Aerogel microparticles were created using a step-pulse pulverizing technique resulting in particle diameters between 425 μm and 90 μm and subsequently embedded in an RTV 655 elastomeric matrix. Aerogel particle concentrations of 25, 50, and 75 wt% were subjected to tensile tests and behavior of the compound material was investigated. Room temperature and cryogenic temperature studies revealed a compound material with rupture load values dependent on (1 microparticle size and (2 microparticle concentration. Results presented show how the stress elongation behavior depends on each parameter.

  16. Experimental study on solids circulation patterns and bubble behavior using particle imagevelocimetry combined with digital image analysis

    NARCIS (Netherlands)

    Laverman, J.A.; Roghair, Ivo; van Sint Annaland, M.; Kuipers, J.A.M.

    2008-01-01

    The hydrodynamics, viz. the solids circulation patterns and bubble behavior, of a freely bubbling gas-solid fluidized bed has been investigated experimentally using Particle Image Velocimetry (PIV) combined with Digital Image Analysis (DIA). Coupling of these non-invasive measuring techniques allows

  17. Advancing our understanding of religion and spirituality in the context of behavioral medicine.

    Science.gov (United States)

    Park, Crystal L; Masters, Kevin S; Salsman, John M; Wachholtz, Amy; Clements, Andrea D; Salmoirago-Blotcher, Elena; Trevino, Kelly; Wischenka, Danielle M

    2017-02-01

    Recognizing and understanding the potentially powerful roles that religiousness and spirituality (RS) may serve in the prevention and amelioration of disease, as well as symptom management and health related quality of life, significantly enhances research and clinical efforts across many areas of behavioral medicine. This article examines the knowledge established to date and suggests advances that remain to be made. We begin with a brief summary of the current knowledge regarding RS as related to three exemplary health conditions: (a) cardiovascular disease; (b) cancer; and, (c) substance abuse. We then focus on particular concerns for future investigations, emphasizing conceptual issues, possible mediators and moderators of relationships or effects, and methodology. Our discussion is framed by a conceptual model that may serve to guide and organize future investigations. This model highlights a number of important issues regarding the study of links between RS and health: (a) RS comprise many diverse constructs, (b) the mechanisms through which RS may influence health outcomes are quite diverse, and (c) a range of different types of health and health relevant outcomes may be influenced by RS. The multidimensional nature of RS and the complexity of related associations with different types of health relevant outcomes present formidable challenges to empirical study in behavioral medicine. These issues are referred to throughout our review and we suggest several solutions to the presented challenges in our summary. We end with a presentation of barriers to be overcome, along with strategies for doing so, and concluding thoughts.

  18. Computational Intelligence-Assisted Understanding of Nature-Inspired Superhydrophobic Behavior.

    Science.gov (United States)

    Zhang, Xia; Ding, Bei; Cheng, Ran; Dixon, Sebastian C; Lu, Yao

    2018-01-01

    In recent years, state-of-the-art computational modeling of physical and chemical systems has shown itself to be an invaluable resource in the prediction of the properties and behavior of functional materials. However, construction of a useful computational model for novel systems in both academic and industrial contexts often requires a great depth of physicochemical theory and/or a wealth of empirical data, and a shortage in the availability of either frustrates the modeling process. In this work, computational intelligence is instead used, including artificial neural networks and evolutionary computation, to enhance our understanding of nature-inspired superhydrophobic behavior. The relationships between experimental parameters (water droplet volume, weight percentage of nanoparticles used in the synthesis of the polymer composite, and distance separating the superhydrophobic surface and the pendant water droplet in adhesive force measurements) and multiple objectives (water droplet contact angle, sliding angle, and adhesive force) are built and weighted. The obtained optimal parameters are consistent with the experimental observations. This new approach to materials modeling has great potential to be applied more generally to aid design, fabrication, and optimization for myriad functional materials.

  19. Advancing our understanding of religion and spirituality in the context of behavioral medicine

    Science.gov (United States)

    Masters, Kevin S.; Salsman, John M.; Wachholtz, Amy; Clements, Andrea D.; Salmoirago-Blotcher, Elena; Trevino, Kelly; Wischenka, Danielle M.

    2016-01-01

    Recognizing and understanding the potentially powerful roles that religiousness and spirituality (RS) may serve in the prevention and amelioration of disease, as well as symptom management and health related quality of life, significantly enhances research and clinical efforts across many areas of behavioral medicine. This article examines the knowledge established to date and suggests advances that remain to be made. We begin with a brief summary of the current knowledge regarding RS as related to three exemplary health conditions: (a) cardiovascular disease; (b) cancer; and, (c) substance abuse. We then focus on particular concerns for future investigations, emphasizing conceptual issues, possible mediators and moderators of relationships or effects, and methodology. Our discussion is framed by a conceptual model that may serve to guide and organize future investigations. This model highlights a number of important issues regarding the study of links between RS and health: (a) RS comprise many diverse constructs, (b) the mechanisms through which RS may influence health outcomes are quite diverse, and (c) a range of different types of health and health relevant outcomes may be influenced by RS. The multidimensional nature of RS and the complexity of related associations with different types of health relevant outcomes present formidable challenges to empirical study in behavioral medicine. These issues are referred to throughout our review and we suggest several solutions to the presented challenges in our summary. We end with a presentation of barriers to be overcome, along with strategies for doing so, and concluding thoughts. PMID:27342616

  20. Using self-determination theory to understand motivation deficits in schizophrenia: the 'why' of motivated behavior.

    Science.gov (United States)

    Gard, David E; Sanchez, Amy H; Starr, Jessica; Cooper, Shanna; Fisher, Melissa; Rowlands, Abby; Vinogradov, Sophia

    2014-07-01

    Self-determination theory (SDT) provides a model for understanding motivation deficits in schizophrenia, and recent research has focused on problems with intrinsic motivation. However, SDT emphasizes that motivated behavior results from three different factors: intrinsic motivators (facilitated by needs for autonomy, competency, and relatedness), extrinsic motivators (towards reward or away from punishment), or when intrinsic and extrinsic motivators are absent or thwarted a disconnect-disengagement occurs resulting in behavior driven by boredom or 'passing time'. Using a novel approach to Ecological Momentary Assessment, we assessed the degree to which people with schizophrenia were motivated by these factors relative to healthy control participants. Forty-seven people with and 41 people without schizophrenia were provided with cell phones and were called four times a day for one week. On each call participants were asked about their goals, and about the most important reason motivating each goal. All responses were coded by independent raters (blind to group and hypotheses) on all SDT motivating factors, and ratings were correlated to patient functioning and symptoms. We found that, relative to healthy participants, people with schizophrenia reported goals that were: (1) less motivated by filling autonomy and competency needs, but equivalently motivated by relatedness; (2) less extrinsically rewarding, but equivalently motivated by punishment; (3) more disconnected-disengaged. Higher disconnected-disengaged goals were significantly associated with higher negative symptoms and lower functioning. These findings indicate several important leverage points for behavioral treatments and suggest the need for vigorous psychosocial intervention focusing on autonomy, competence, and reward early in the course of illness. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Himalayan glaciers: understanding contrasting patterns of glacier behavior using multi-temporal satellite imagery

    Science.gov (United States)

    Racoviteanu, A.

    2014-12-01

    High rates of glacier retreat for the last decades are often reported, and believed to be induced by 20th century climate changes. However, regional glacier fluctuations are complex, and depend on a combination of climate and local topography. Furthermore, in ares such as the Hindu-Kush Himalaya, there are concerns about warming, decreasing monsoon precipitation and their impact on local glacier regimes. Currently, the challenge is in understanding the magnitude of feedbacks between large-scale climate forcing and small-scale glacier behavior. Spatio-temporal patterns of glacier distribution are still llimited in some areas of the high Hindu-Kush Himalaya, but multi-temporal satellite imagery has helped fill spatial and temporal gaps in regional glacier parameters in the last decade. Here I present a synopsis of the behavior of glaciers across the Himalaya, following a west to east gradient. In particular, I focus on spatial patterns of glacier parameters in the eastern Himalaya, which I investigate at multi-spatial scales using remote sensing data from declassified Corona, ASTER, Landsat ETM+, Quickbird and Worldview2 sensors. I also present the use of high-resolution imagery, including texture and thermal analysis for mapping glacier features at small scale, which are particularly useful in understanding surface trends of debris-covered glaciers, which are prevalent in the Himalaya. I compare and contrast spatial patterns of glacier area and élévation changes in the monsoon-influenced eastern Himalaya (the Everest region in the Nepal Himalaya and Sikkim in the Indian Himalaya) with other observations from the dry western Indian Himalaya (Ladakh and Lahul-Spiti), both field measurements and remote sensing-based. In the eastern Himalaya, results point to glacier area change of -0.24 % ± 0.08% per year from the 1960's to the 2006's, with a higher rate of retreat in the last decade (-0.43% /yr). Debris-covered glacier tongues show thinning trends of -30.8 m± 39 m

  2. Measuring laves phase particle size and thermodynamic calculating its growth and coarsening behavior in P92 steels

    DEFF Research Database (Denmark)

    Yao, Bing-Yin; Zhou, Rong-Can; Fan, Chang-Xin

    2010-01-01

    The growth of Laves phase particles in three kinds of P92 steels were investigated. Laves phase particles can be easily separated and distinguished from the matrix and other particles by atom number contrast using comparisons of the backscatter electrons (BSE) images and the secondary electrons (SE......) images in scanning electron microscope (SEM). The smaller Laves phase particle size results in higher creep strength and longer creep exposure time at the same conditions. DICTRA software was used to model the growth and coarsening behavior of Laves phase in the three P92 steels. Good agreements were...... attained between measurements in SEM and modeling by DICTRA. Ostwald ripening should be used for the coarsening calculation of Laves phase in P92 steels for time longer than 20000 h and 50000 h at 650°C and 600°C, respectively. © 2010 Chin. Soc. for Elec. Eng....

  3. Process analytical technology to understand the disintegration behavior of alendronate sodium tablets.

    Science.gov (United States)

    Xu, Xiaoming; Gupta, Abhay; Sayeed, Vilayat A; Khan, Mansoor A

    2013-05-01

    Various adverse events including esophagus irritations have been reported with the use of alendronate tablets, likely attributed to the rapid tablet disintegration in the mouth or esophagus. Accordingly, the disintegration of six alendronate tablet drug products was studied using a newly developed testing device equipped with in-line sensors, in addition to the official compendial procedure for measuring the disintegration time. The in-line sensors were used to monitor the particle count and solution pH change to assess the onset and duration of disintegration. A relatively large variation was observed in the disintegration time of the tested drug products using the compendial method. The data collected using the in-line sensors suggested that all tested drug products exhibited almost instantaneous onset of disintegration, under 2 s, and a sharp drop in solution pH. The drop in pH was slower for tablets with slower disintegration. The in-house prepared alendronate test tablets also showed similar trends suggesting rapid solubilization of the drug contributed to the fast tablet disintegration. This research highlights the usefulness of the newly developed in-line analytical method in combination with the compendial method in providing a better understanding of the disintegration and the accompanying drug solubilization processes for fast disintegrating tablet drug products. Copyright © 2013 Wiley Periodicals, Inc.

  4. Understanding the Behavior of the Oligomeric Fractions During Pyrolysis Oils Upgrading

    Science.gov (United States)

    Stankovikj, Filip

    Fast pyrolysis oils represent most viable renewable sources for production of fuels and chemicals, and they could supplement significant portion of the depleting fossil fuels in near future. Progress on their utilization is impeded by their thermal and storage instability, lack of understanding of their complex composition and behavior during upgrading, including the poorly described water soluble fraction (WS). This work offers two new methodologies for simplified, and sensible description of the pyrolysis oils in terms of functional groups and chemical macro-families, augments our understanding of the composition of the WS, and the behavior of the heavy non-volatile fraction during pyrolysis oils stabilization. The concept of analyzing the volatile and non-volatile fraction in terms of functional groups has been introduced, and the quantification power of spectroscopic techniques (FTIR, 1H-NMR, UV fluorescence) for phenols, carbonyl and carboxyl groups was shown. The FT-ICR-MS van Krevelen diagram revealed the importance of dehydration reactions in pyrolysis oils and the presence of "pyrolytic humins" was hypothesized. For the first time the WS was analyzed with plethora of analytical techniques. This lead to proposition of a new characterization scheme based on functional groups, describing 90-100 wt.% of the bio-oils. The structure of idealized "pyrolytic humin" was further described as a random combination of 3-8 units of dehydrated sugars, coniferyl-type phenols, furans, and carboxylic acids attached on a 2,5-dioxo-6-hydroxyhexanal (DHH) backbone rich in carbonyl groups. TG-FTIR studies resulted in defining rules for fitting pyrolysis oils' DTG curves and assignment of TG residue. This second method is reliable for estimation of water content, light volatiles, WS and WIS. Finally, stabilization of two oils was analyzed through the prism of functional groups. Carbonyl and hydroxyl groups interconverted. The first attempt to follow silent 31P-NMR oxygen was

  5. Using the Integrative Model of Behavioral Prediction to Understand College Students' STI Testing Beliefs, Intentions, and Behaviors.

    Science.gov (United States)

    Wombacher, Kevin; Dai, Minhao; Matig, Jacob J; Harrington, Nancy Grant

    2018-03-22

    To identify salient behavioral determinants related to STI testing among college students by testing a model based on the integrative model of behavioral (IMBP) prediction. 265 undergraduate students from a large university in the Southeastern US. Formative and survey research to test an IMBP-based model that explores the relationships between determinants and STI testing intention and behavior. Results of path analyses supported a model in which attitudinal beliefs predicted intention and intention predicted behavior. Normative beliefs and behavioral control beliefs were not significant in the model; however, select individual normative and control beliefs were significantly correlated with intention and behavior. Attitudinal beliefs are the strongest predictor of STI testing intention and behavior. Future efforts to increase STI testing rates should identify and target salient attitudinal beliefs.

  6. Understanding the Non-Gaussian Nature of Linear Reactive Solute Transport in 1D and 2D : From Particle Dynamics to the Partial Differential Equations

    NARCIS (Netherlands)

    Uffink, G.J.M.; Elfeki, A.; Dekking, M.; Bruining, J.; Kraaikamp, C.

    2011-01-01

    In the present study, we examine non-Gaussian spreading of solutes subject to advection, dispersion and kinetic sorption (adsorption/desorption). We start considering the behavior of a single particle and apply a random walk to describe advection/dispersion plus a Markov chain to describe kinetic

  7. Modulating mimicry: Exploring the roles of inhibitory control and social understanding in 5-year-olds' behavioral mimicry.

    Science.gov (United States)

    van Schaik, Johanna E; Hunnius, Sabine

    2018-01-01

    During adult interactions, behavioral mimicry, the implicit copying of an interaction partner's postures and mannerisms, communicates liking and affiliation. While this social behavior likely develops during early childhood, it is unclear which factors contribute to its emergence. Here, the roles of inhibitory control and social understanding on 5-year-olds' behavioral mimicry were investigated. Following a social manipulation in which one experimenter shared a sticker with the child and the other experimenter kept two stickers for herself, children watched a video in which these experimenters each told a story. During this story session, children in the experimental group (n = 28) observed the experimenters perform face and hand rubbing behaviors whereas the control group (n = 23) did not see these behaviors. Children's inhibitory control was assessed using the day-night task and their social understanding was measured through a parental questionnaire. Surprisingly, group-level analyses revealed that the experimental group performed the behaviors significantly less than the control group (i.e. a negative mimicry effect) for both the sticker-sharer and sticker-keeper. Yet, the hypothesized effects of inhibitory control and social understanding were found. Inhibitory control predicted children's selective mimicry of the sticker-keeper versus sticker-sharer and children's overall mimicry was correlated with social understanding. These results provide the first indications to suggest that factors of social and cognitive development dynamically influence the emergence and specificity of behavioral mimicry during early childhood.

  8. Clay preference and particle transport behavior of Formosan subterranean termites (Isoptera: Rhinotermitidae): a laboratory study.

    Science.gov (United States)

    Wang, Cai; Henderson, Gregg

    2014-12-01

    Although preference and utilization of clay have been studied in many higher termites, little attention has been paid to lower termites, especially subterranean termites. The Formosan subterranean termite, Coptotermes formosanus Shiraki, can modify its habitat by using clay to fill tree cavities. Here, the biological significance of clay on C. formosanus was investigated. Choice tests showed that significantly more termites aggregated in chambers where clay blocks were provided, regardless of colony group, observation period, or nutritional condition (fed or starved). No-choice tests showed that clay had no observable effect on survivorship, live or dry biomass, water content, and tunneling activity after 33-35 d. However, clay appeared to significantly decrease filter paper consumption (dry weight loss). Active particle (sand, paper, and clay) transport behavior was observed in both choice and no-choice tests. When present, clay was preferentially spread on the substrate, attached to the smooth surfaces of the containers, and used to line sand tunnels. Mechanisms and potential application of clay attraction are discussed. © 2013 Institute of Zoology, Chinese Academy of Sciences.

  9. Coupling an aerosol box model with one-dimensional flow: a tool for understanding observations of new particle formation events

    Directory of Open Access Journals (Sweden)

    Niku Kivekäs

    2016-04-01

    Full Text Available Field observations of new particle formation and the subsequent particle growth are typically only possible at a fixed measurement location, and hence do not follow the temporal evolution of an air parcel in a Lagrangian sense. Standard analysis for determining formation and growth rates requires that the time-dependent formation rate and growth rate of the particles are spatially invariant; air parcel advection means that the observed temporal evolution of the particle size distribution at a fixed measurement location may not represent the true evolution if there are spatial variations in the formation and growth rates. Here we present a zero-dimensional aerosol box model coupled with one-dimensional atmospheric flow to describe the impact of advection on the evolution of simulated new particle formation events. Wind speed, particle formation rates and growth rates are input parameters that can vary as a function of time and location, using wind speed to connect location to time. The output simulates measurements at a fixed location; formation and growth rates of the particle mode can then be calculated from the simulated observations at a stationary point for different scenarios and be compared with the ‘true’ input parameters. Hence, we can investigate how spatial variations in the formation and growth rates of new particles would appear in observations of particle number size distributions at a fixed measurement site. We show that the particle size distribution and growth rate at a fixed location is dependent on the formation and growth parameters upwind, even if local conditions do not vary. We also show that different input parameters used may result in very similar simulated measurements. Erroneous interpretation of observations in terms of particle formation and growth rates, and the time span and areal extent of new particle formation, is possible if the spatial effects are not accounted for.

  10. A Comprehensive Understanding of Machine and Material Behaviors During Inertia Friction Welding

    Science.gov (United States)

    Tung, Daniel J.

    Inertia Friction Welding (IFW), a critical process to many industries, currently relies on trial-and-error experimentation to optimize process parameters. Although this Edisonian approach is very effective, the high time and dollar costs incurred during process development are the driving force for better design approaches. Thermal-stress finite element modeling has been increasingly used to aid in process development in the literature; however, several fundamental questions on machine and material behaviors remain unanswered. The work presented here aims produce an analytical foundation to significantly reduce the costly physical experimentation currently required to design the inertia welding of production parts. Particularly, the work is centered around the following two major areas. First, machine behavior during IFW, which critically determines deformation and heating, had not been well understood to date. In order to properly characterize the IFW machine behavior, a novel method based on torque measurements was invented to measure machine efficiency, i.e. the ratio of the initial kinetic energy of the flywheel to that contributing to workpiece heating and deformation. The measured efficiency was validated by both simple energy balance calculations and more sophisticated finite element modeling. For the first time, the efficiency dependence on both process parameters (flywheel size, initial rotational velocity, axial load, and surface roughness) and materials (1018 steel, Low Solvus High Refractory LSHR and Waspaloy) was quantified using the torque based measurement method. The effect of process parameters on machine efficiency was analyzed to establish simple-to-use yet powerful equations for selection and optimization of IFW process parameters for making welds; however, design criteria such as geometry and material optimization were not addressed. Second, there had been a lack of understanding of the bond formation during IFW. In the present research, an

  11. Stress, cues, and eating behavior. Using drug addiction paradigms to understand motivation for food.

    Science.gov (United States)

    Stojek, Monika Kardacz; Fischer, Sarah; MacKillop, James

    2015-09-01

    Eating patterns that lead to overconsumption of high fat, high sugar (HFHS) foods share similar features with addictive behaviors. Application of addiction paradigms, such as stress inductions, cue reactivity and behavioral economic assessments, to the study of motivation for HFHS food consumption may be a promising means of understanding food consumption. To date, few studies have investigated the interaction of stress and environmental cues on craving, and no study leveraged the state relative reinforcing value of foods (RRVfood) under varying conditions of affective states, the foci of the current study. This study used a mixed factorial design (Mood Induction: Neutral, Stress; Cues: Neutral, Food) with repeated measures on time (Baseline, Post-Mood Induction, Post-Cue Exposure). Participants (N = 133) were community adults who endorsed liking of HFHS snacks but denied eating pathology. The primary DVs were subjective craving and RRVfood. Negative and positive affect (NA, PA), the amount of food consumed, and latency to first bite were also examined. Participants in the Stress condition reported no change in craving or RRVfood. Exposure to food cues significantly increased participants' craving and RRVfood, but an interaction of stress and cues was not present. Participants did not differ on how many calories they consumed based on exposure to stress or food cues, but participants in the food cues condition had a shorter latency to the first bite of food. This study highlights the importance of environmental cues in food motivation. It also demonstrates the utility of using RRVfood to further characterize food motivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Thermomechanical behavior of fuel particles in a matrix during reactor power excursions

    International Nuclear Information System (INIS)

    Brittan, R.O.; Smith, R.S.

    1977-01-01

    This work determines the largest particle size that can be used in fabricating fuel material without exceeding temperature or stress criteria during transient operation. To do this temperature distribution histories must be determined for various particle sizes and volume fractions using typical power densities histories of transient reactor operation. From these, the critical stresses are calculated. The model chosen to accomplish this is a spherical fuel particle in a spherical matrix shell. Heat flow and temperature continuity conditions are imposed at the interface, and a zero temperature gradient is specified at the outer radius of the matrix shell. The particle power density is assumed to be uniform radially. Provisions are made for uniform power density in the matrix to model gamma heating and power density in interface layers to allow for radiant and fission fragment heating. A computer code was prepared to solve the model performance, yielding the temperature and stress distribution histories. Material property variation with temperature is employed, along with a close mockup of the power density history during self-limiting reactor transients. To date, four fuel systems have been investigated: 1) UC.ZrC particles in graphite; 2) UO 2 particles in graphite; 3) UO 2 particles in chromium 4) UO 2 particles in stainless steel. The study indicates that the maximum allowable particle diameter varies as the square root of the initial transient period and of the particle volume fraction. The critical thermophysical parameter is the thermal diffusivity of the particle, since in all cases studied it is many times smaller than that of the matrix. That of the UC.ZrC solid solution particle is 5 or more times larger than that of the UO 2 particle. It was found that the particles of system 1) above could be about 4 times larger than that of the other sy

  13. Understanding implications of consumer behavior for wildlife farming and sustainable wildlife trade.

    Science.gov (United States)

    Nuno, A; Blumenthal, J M; Austin, T J; Bothwell, J; Ebanks-Petrie, G; Godley, B J; Broderick, A C

    2018-04-01

    Unsustainable wildlife trade affects biodiversity and the livelihoods of communities dependent upon those resources. Wildlife farming has been proposed to promote sustainable trade, but characterizing markets and understanding consumer behavior remain neglected but essential steps in the design and evaluation of such operations. We used sea turtle trade in the Cayman Islands, where turtles have been farm raised for human consumption for almost 50 years, as a case study to explore consumer preferences toward wild-sourced (illegal) and farmed (legal) products and potential conservation implications. Combining methods innovatively (including indirect questioning and choice experiments), we conducted a nationwide trade assessment through in-person interviews from September to December 2014. Households were randomly selected using disproportionate stratified sampling, and responses were weighted based on district population size. We approached 597 individuals, of which 37 (6.2%) refused to participate. Although 30% of households had consumed turtle in the previous 12 months, the purchase and consumption of wild products was rare (e.g., 64-742 resident households consumed wild turtle meat [i.e., 0.3-3.5% of households] but represented a large threat to wild turtles in the area due to their reduced populations). Differences among groups of consumers were marked, as identified through choice experiments, and price and source of product played important roles in their decisions. Despite the long-term practice of farming turtles, 13.5% of consumers showed a strong preference for wild products, which demonstrates the limitations of wildlife farming as a single tool for sustainable wildlife trade. By using a combination of indirect questioning, choice experiments, and sales data to investigate demand for wildlife products, we obtained insights about consumer behavior that can be used to develop conservation-demand-focused initiatives. Lack of data from long-term social

  14. The Asymptotic Behavior of Particle Size Distribution Undergoing Brownian Coagulation Based on the Spline-Based Method and TEMOM Model

    Directory of Open Access Journals (Sweden)

    Qing He

    2018-01-01

    Full Text Available In this paper, the particle size distribution is reconstructed using finite moments based on a converted spline-based method, in which the number of linear system of equations to be solved reduced from 4m × 4m to (m + 3 × (m + 3 for (m + 1 nodes by using cubic spline compared to the original method. The results are verified by comparing with the reference firstly. Then coupling with the Taylor-series expansion moment method, the evolution of particle size distribution undergoing Brownian coagulation and its asymptotic behavior are investigated.

  15. Understanding reflection behavior as a key for interpreting complex signals in FBRM monitoring of microparticle preparation processes.

    Science.gov (United States)

    Vay, Kerstin; Friess, Wolfgang; Scheler, Stefan

    2012-11-01

    The application of focused beam reflectance measurement (FBRM) was studied in a larger scale PLGA microparticle preparation process for monitoring changes of the particle size and the particles' surface properties. Further understanding how these parameters determine the chord length distribution (CLD) was gained by means of single object measurements and data of monodisperse microparticles. It was evaluated how the FBRM signal is influenced by the surface characteristics of the tested materials and the measuring conditions. Particles with good scattering properties provided comparable values for the CLD and the particle size distribution. Translucent particles caused an overestimation of the particle size by FBRM, whereas the values for transparent emulsion droplets were too low. Despite a strong dependence of FBRM results on the optical properties of the samples, it is a beneficial technique for online monitoring of microparticle preparation processes. The study demonstrated how changing reflection properties can be used to monitor structural changes during the solidification of emulsion droplets and to detect process instabilities by FBRM. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Comb polymer architecture and particle size effects on the behavior of biphasic nanoparticle inks for direct-write assembly

    Science.gov (United States)

    Yoshikawa, Jun

    Biphasic nanoparticle mixtures composed of attractive and repulsive colloidal species enable the direct-write assembly of 3D structures with much finer features than those produced by pure colloidal gels. These mixtures rely on the use of comb polymer dispersants to render one particle population stable, while the other population is attractive. In this thesis, we systematically investigate the effects of comb polymer architecture and particle size ratio on the behavior of biphasic nanoparticle inks with the overarching aim of further advancing the direct-write assembly of 3D colloidal structures. We first investigated the effects of both pure polyelectrolytes, poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA), and comb polymer dispersants composed of a PMAA backbone with methoxy-poly(ethylene oxide) (mPEO) teeth of varying molecular weights on the stability of barium titanate (BaTiO 3) suspensions. While each dispersant imparts stability to BaTiO 3 nanoparticles at low ionic strength (teeth (MWteeth = 2000) provides stability at higher ionic strengths over a broad range of particle sizes and counterion valencies. These results provide guidelines for tailoring the molecular architecture and functionality of comb polymer dispersants for optimal stabilization of the repulsive particle population within the biphasic inks. Next, particle size effects on the rheological properties of biphasic nanoparticle suspensions are studied. Shear elastic modulus, shear yield stress, and compressive yield stress are measured for mixtures of varying total volume fraction, attractive-to-repulsive volume fraction, and particle size ratio between attractive and repulsive species. Our observations indicate that the repulsive particles hinder the formation of the attractive gel network. The time required for shear elastic modulus to approach a steady-state value increases with the fraction of repulsive species. Furthermore, this behavior becomes more significant with increasing

  17. Inner-City African-American Women's Adolescence as Stressful Life Events: Understanding Substance Abusing Behavior.

    Science.gov (United States)

    Durr, Marlese; Small, La Fleur F; Dunlap, Eloise

    2010-06-01

    Lula Beatty (2003:59) asks, "What makes a black woman, voluntarily take a substance into her body which alters her perceptions and feelings of well-being?" This research examines African American women's substance abuse as a response to stressful life events grounded in adolescence, drawing in part on the cognitive-transactional approach and distal stressor model to discuss the effects of stressors on mental health and substance abusing behavior. Most respondents viewed their adolescent experiences and the associated stress as tribulations or lessons to be lived through, rather than a signal of needed change in their social, cultural, and ecological life circumstances. The effect of exposure to constant stressors early in the life course coupled with proximal stressors often resulted in negative active responses to stress (i.e. substance abuse) and continued stunted emotional growth. Thus, our findings indicate that the experience of African American women as adolescents contributes to understanding substance abuse amongst this population. These findings further help develop the cognitive-transactional model, while adding to the distal stressors and life process model as a way of considering gender, race, and structural forces.

  18. Understanding watershed hydrogeochemistry: 2. Synchronized hydrological and geochemical processes drive stream chemostatic behavior

    Science.gov (United States)

    Li, Li; Bao, Chen; Sullivan, Pamela L.; Brantley, Susan; Shi, Yuning; Duffy, Christopher

    2017-03-01

    Why do solute concentrations in streams remain largely constant while discharge varies by orders of magnitude? We used a new hydrological land surface and reactive transport code, RT-Flux-PIHM, to understand this long-standing puzzle. We focus on the nonreactive chloride (Cl) and reactive magnesium (Mg) in the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO). Simulation results show that stream discharge comes from surface runoff (Qs), soil lateral flow (QL), and deeper groundwater (QG), with QL contributing >70%. In the summer, when high evapotranspiration dries up and disconnects most of the watershed from the stream, Cl is trapped along planar hillslopes. Successive rainfalls connect the watershed and mobilize trapped Cl, which counteracts dilution effects brought about by high water storage (Vw) and maintains chemostasis. Similarly, the synchronous response of clay dissolution rates (Mg source) to hydrological conditions, maintained largely by a relatively constant ratio between "wetted" mineral surface area Aw and Vw, controls Mg chemostatic behavior. Sensitivity analysis indicates that cation exchange plays a secondary role in determining chemostasis compared to clay dissolution, although it does store an order-of-magnitude more Mg on exchange sites than soil water. Model simulations indicate that dilution (concentration decrease with increasing discharge) occurs only when mass influxes from soil lateral flow are negligible (e.g., via having low clay surface area) so that stream discharge is dominated by relatively constant mass fluxes from deep groundwater that are unresponsive to surface hydrological conditions.

  19. Understanding of action-related and abstract verbs in comparison: a behavioral and TMS study.

    Science.gov (United States)

    Innocenti, Alessandro; De Stefani, Elisa; Sestito, Mariateresa; Gentilucci, Maurizio

    2014-02-01

    Does the comprehension of both action-related and abstract verbs rely on motor simulation? In a behavioral experiment, in which a semantic task was used, response times to hand-action-related verbs were briefer than those to abstract verbs and both decreased with repetition of presentation. In a transcranial magnetic stimulation (TMS) experiment, single-pulse stimulation was randomly delivered over hand motor area of the left primary motor cortex to measure cortical-spinal excitability at 300 or 500 ms after verb presentation. Two blocks of trials were run. In each block, the same verbs were randomly presented. In the first block, stimulation induced an increase in motor evoked potentials only when TMS was applied 300 ms after action-related verb presentation. In the second block, no modulation of motor cortex was found according to type of verb and stimulation-delay. These results confirm that motor simulation can be used to understand action rather than abstract verbs. Moreover, they suggest that with repetition, the semantic processing for action verbs does not require activation of primary motor cortex anymore.

  20. Trying not to get burned: understanding homeowners' wildfire risk-mitigation behaviors.

    Science.gov (United States)

    Brenkert-Smith, Hannah; Champ, Patricia A; Flores, Nicholas

    2012-12-01

    Three causes have been identified for the spiraling cost of wildfire suppression in the United States: climate change, fuel accumulation from past wildfire suppression, and development in fire-prone areas. Because little is likely to be performed to halt the effects of climate on wildfire risk, and because fuel-management budgets cannot keep pace with fuel accumulation let alone reverse it, changing the behaviors of existing and potential homeowners in fire-prone areas is the most promising approach to decreasing the cost of suppressing wildfires in the wildland-urban interface and increasing the odds of homes surviving wildfire events. Wildfire education efforts encourage homeowners to manage their property to decrease wildfire risk. Such programs may be more effective with a better understanding of the factors related to homeowners' decisions to undertake wildfire risk-reduction actions. In this study, we measured whether homeowners had implemented 12 wildfire risk-mitigation measures in 2 Colorado Front Range counties. We found that wildfire information received from local volunteer fire departments and county wildfire specialists, as well as talking with neighbors about wildfire, were positively associated with higher levels of mitigation. Firsthand experience in the form of preparing for or undertaking an evacuation was also associated with a higher level of mitigation. Finally, homeowners who perceived higher levels of wildfire risk on their property had undertaken higher levels of wildfire-risk mitigation on their property.

  1. Overview of rehabilitative efforts in understanding and managing sexually coercive behaviors.

    Science.gov (United States)

    Schwartz, Barbara K

    2003-06-01

    In reviewing approaches to rehabilitative efforts in understanding and managing sexually coercive behaviors within the past two decades, one is struck by the development of two totally divergent paths. In 1971, there were a few civil commitment programs operated by mental health departments-most notably were the Sexual Psychopath Program at Western State Hospital in Fort Steilacoom, Washington, and the Massachusetts Treatment Center for Sexually Dangerous Persons. There were a few programs in prisons started by therapists who were interested in this population but given little recognition and even fewer resources. Additionally there were a handful of community-based programs including the J.J. Peters Institute in Philadelphia and PASO (Positive Approaches to Sex Offenders) in Albuquerque, New Mexico. Today there are thousands of specialized sexual offender treatment programs treating sexual abusers of every age, gender, ethnicity, and with a wide range of comorbid conditions. They are treated in the community, prisons, mental hospitals, residential facilities, and private practices. There is an international organization, a specialized research journal, and a specialized branch of the Department of Justice, the Center for Sex Offender Management. This chapter will provide an overview of the developments in the field, primarily covering the last 25 years. It will look at the evolution of theoretical approaches, the development of specialized approaches for subpopulations, significant landmarks, and possible future trends.

  2. Evaluating Students' Understanding of Kinetic Particle Theory Concepts Relating to the States of Matter, Changes of State and Diffusion: A Cross-National Study

    Science.gov (United States)

    Treagust, David F.; Chandrasegaran, A. L.; Crowley, Julianne; Yung, Benny H. W.; Cheong, Irene P.-A.; Othman, Jazilah

    2010-01-01

    This paper reports on the understanding of three key conceptual categories relating to the kinetic particle theory: (1) intermolecular spacing in solids, liquids and gases, (2) changes of state and intermolecular forces and (3) diffusion in liquids and gases, amongst 148 high school students from Brunei, Australia, Hong Kong and Singapore using 11…

  3. An empirical approach to predicting long term behavior of metal particle based recording media

    Science.gov (United States)

    Hadad, Allan S.

    1992-01-01

    Alpha iron particles used for magnetic recording are prepared through a series of dehydration and reduction steps of alpha-Fe2O3-H2O resulting in acicular, polycrystalline, body centered cubic (bcc) alpha-Fe particles that are single magnetic domains. Since fine iron particles are pyrophoric by nature, stabilization processes had to be developed in order for iron particles to be considered as a viable recording medium for long term archival (i.e., 25+ years) information storage. The primary means of establishing stability is through passivation or controlled oxidation of the iron particle's surface. A study was undertaken to examine the degradation in magnetic properties as a function of both temperature and humidity on silicon-containing iron particles between 50-120 C and 3-89 percent relative humidity. The methodology to which experimental data was collected and analyzed leading to predictive capability is discussed.

  4. Behavior of the particle transport coefficients near the density limit in MTX

    International Nuclear Information System (INIS)

    Marinak, M.M.

    1993-04-01

    The perturbed particle transport coefficients were determined for a range of plasma conditions in the Alcator C tokamak, a component of the Microwave Tokamak Experiment (MTX), from analysis of density perturbations created in gas modulation experiments. Density measurements from a 15 chord far-infrared interferometer were sufficiently detailed to allow radial profiles of the transport coefficients to be resolved. Gas modulation experiments were carried out on plasmas over a range of relatively low currents and a wide variety of line-averaged densities, including values near the Greenwald density limit. With this technique the perturbed diffusion coefficient D and the perturbed convection velocity V can be determined simultaneously. Measured profiles of D rise toward the outside of the plasma column in a manner generally similar to those determined previously for χ e,HP from sawtooth heat pulse propagation. Values of D are typically smaller than those of χ e,HP given for the same line-averaged densities by a factor of 2-5. Diffusion coefficients from a series of discharges at constant current showed little variation with density through most of the saturated ohmic confinement regime. At the Greenwald density limit threshold a dramatic increase occurred in both the perturbed convective and diffusive transport coefficients in the outer region of the plasma. The increases were most pronounced at the outermost range of the radii where coefficients were determined (r/a = 0.8), but were apparent over a region which extended well into the plasma interior. Density profiles maintained a similar shape near the density limit, congruous with the similar behavior of the transport coefficients. No dramatic deterioration was evident in the global energy confinement

  5. A qualitative study to understand positive and negative child feeding behaviors of immigrant Asian Indian mothers in the US.

    Science.gov (United States)

    Momin, Shabnam R; Chung, Kimberly R; Olson, Beth H

    2014-09-01

    To understand current practice of child feeding behaviors, and underlying factors influencing these practices in Asian Indian mothers, qualitative in-depth interviews were conducted with 27 immigrant Asian Indian mothers of children ages 5-10 years. Using the theory of planned behavior as a guiding framework, child feeding behaviors employed, beliefs about the outcomes of feeding behaviors, perceived ease or difficultly in practicing feeding behaviors, and social norms were explored during the interviews. Thematic analysis was conducted using coding and display matrices. Mothers were motivated by nutrition outcomes when practicing positive and negative controlling feeding behaviors. Outcomes related to preservation of Indian culture and values also influenced feeding behaviors. Pressuring to eat was often practiced despite the perception of ineffectiveness. Use of food rewards was found, and use of TV to control children's food intake despite the clear understanding of undesirable nutrition outcomes was a unique finding. Asian Indian mothers need effective child feeding strategies that are culturally appropriate. Integrating cultural beliefs in nutrition education could help support existing motivation and behavior modification.

  6. Particle and impurity transport in the Axial Symmetric Divertor Experiment Upgrade and the Joint European Torus, experimental observations and theoretical understanding

    DEFF Research Database (Denmark)

    Angioni, C.; Carraro, L.; Dannert, T.

    2007-01-01

    Experimental observations on core particle and impurity transport from the Axial Symmetric Divertor Experiment Upgrade [O. Gruber, H.-S. Bosch, S. Gunter , Nucl Fusion 39, 1321 (1999)] and the Joint European Torus [J. Pamela, E. R. Solano, and JET EFDA Contributors, Nucl. Fusion 43, 1540 (2003......)] tokamaks are reviewed and compared. Robust general experimental behaviors observed in both the devices and related parametric dependences are identified. The experimental observations are compared with the most recent theoretical results in the field of core particle transport. (C) 2007 American Institute...

  7. Using video technology to disseminate behavioral procedures: a review of Functional Analysis: a Guide for Understanding Challenging Behavior (DVD).

    Science.gov (United States)

    Carr, James E; Fox, Eric J

    2009-01-01

    Although applied behavior analysis has generated many highly effective behavior-change procedures, the procedures have not always been effectively disseminated. One solution to this problem is the use of video technology, which has been facilitated by the ready availability of video production equipment and software and multiple distribution methods (e.g., DVD, online streaming). We review a recent DVD that was produced to disseminate the successful experimental functional analysis procedure. The review is followed by general recommendations for disseminating behavior-analytic procedures via video technology.

  8. Evaluation of the influence of parental anxiety on children's behavior and understanding children's dental anxiety after sequential dental visits

    OpenAIRE

    Swapnali Dilip Shinde; Rahul J Hegde

    2017-01-01

    Background: Identifying anxiety levels of parents accompanying their children can help the clinician in designing the behavior management strategies for the child. In addition, continued dental experience can improve the child's response, indicating desensitization to dental stress. Aims: To evaluate the influence of parental anxiety on children's behavior and understanding children's dental anxiety after sequential dental visits. Materials and Methods: A total of 175 children of age 6–12 yea...

  9. Behavior of a spin-1/2 massive charged particle in Schwarzschild immersed in an electromagnetic universe

    Science.gov (United States)

    Al-Badawi, A.

    2018-02-01

    The Dirac equation is considered in a spacetime that represents a Schwarzschild metric coupled to a uniform external electromagnetic field. Due to the presence of electromagnetic field from the surroundings, the interaction with the spin-1/2 massive charged particle is considered. The equations of the spin-1/2 massive charged particle are separated into radial and angular equations by adopting the Newman-Penrose formalism. The angular equations obtained are similar to the Schwarzschild geometry. For the radial equations we manage to obtain the one dimensional Schrödinger-type wave equations with effective potentials. Finally, we study the behavior of the potentials by plotting them as a function of radial distance and expose the effect of the external parameter, charge and the frequency of the particle on them.

  10. Fatigue behavior of Ti6Al4V and 316 LVM blasted with ceramic particles of interest for medical devices.

    Science.gov (United States)

    Barriuso, S; Chao, J; Jiménez, J A; García, S; González-Carrasco, J L

    2014-02-01

    Grit blasting is used as a cost-effective method to increase the surface roughness of metallic biomaterials, as Ti6Al4V and 316 LVM, to enhance the osteointegration, fixation and stability of implants. Samples of these two alloys were blasted by using alumina and zirconia particles, yielding rough (up to Ra~8μm) and nearly smooth (up to Ra~1μm) surfaces, respectively. In this work, we investigate the sub-surface induced microstructural effects and its correlation with the mechanical properties, with special emphasis in the fatigue behavior. Blasting with zirconia particles increases the fatigue resistance whereas the opposite effect is observed using alumina ones. As in a conventional shot penning process, the use of rounded zirconia particles for blasting led to the development of residual compressive stresses at the surface layer, without zones of stress concentrators. Alumina particles are harder and have an angular shape, which confers a higher capability to abrade the surface, but also a high rate of breaking down on impact. The higher roughness and the presence of a high amount of embedded alumina particles make the blasted alloy prone to crack nucleation. Interestingly, the beneficial or detrimental role of blasting is more intense for the Ti6Al4V alloy than for the 316 steel. It is proposed that this behavior is related to their different strain hardening exponents and the higher mass fraction of particles contaminating the surface. The low value of this exponent for the Ti6Al4V alloy justifies the expected low sub-surface hardening during the severe plastic deformation, enhancing its capability to soft during cyclic loading. © 2013 Published by Elsevier Ltd.

  11. Hot plasma and energetic particles in the earth's outer magnetosphere: new understandings during the IMS

    Energy Technology Data Exchange (ETDEWEB)

    Baker, D.N.; Fritz, T.A.

    1984-01-01

    In this paper we review the major accomplishments made during the IMS period in clarifying magnetospheric particle variations in the region from roughly geostationary orbit altitudes into the deep magnetotail. We divide our review into three topic areas: (1) acceleration processes; (2) transport processes; and (3) loss processes. Many of the changes in hot plasmas and energetic particle populations are often found to be related intimately to geomagnetic storm and magnetospheric substorm effects and, therefore, substantial emphasis is given to these aspects of particle variations in this review. The IMS data, taken as a body, allow a reasonably unified view as one traces magnetospheric particles from their acceleration source through the plasma sheet and outer trapping regions and, finally, to their loss via ionospheric precipitation and ring current formation processes. It is this underlying, unifying theme which is pursued here. 52 references, 19 figures.

  12. Understanding caregivers' intentions for their child to walk to school: Further application of the theory of planned behavior.

    Science.gov (United States)

    Schuster, Lisa; Kubacki, Krzysztof; Rundle-Thiele, Sharyn

    2016-01-01

    Increases in childhood obesity have coincided with declines in active transportation to school. This research builds on largely atheoretical extant literature examining factors that influence walk-to-school behavior through application of the theory of planned behavior (TPB). Understanding caregivers' decision for their child to walk to/from school is key to developing interventions to promote this cost-effective and accessible health behavior. The results from an online survey of 512 caregivers provide support for the TPB, highlighting the important role of subjective norms. This suggests marketers should nurture caregivers' perception that important others approve of walking to school.

  13. Lattice Boltzmann simulation of the behavior of spherical and nonspherical particles in a square pipe flow

    Science.gov (United States)

    Inamuro, Takaji; Hayashi, Hirofumi; Koshiyama, Masahiro

    2008-11-01

    The lattice Boltzmann method (LBM) for multicomponent immiscible fluids is applied to the simulations of solid-fluid mixture flows including spherical and nonspherical particles in a square pipe. A spherical solid particle is modeled by a droplet with strong interfacial tension and large viscosity, and consequently there is no need to track the moving solid-liquid boundary explicitly. Nonspherical (discoid and biconcave discoid) solid particles are made by applying artificial forces to the spherical droplet. It is found that spherical particles move around stable positions between the wall and the center of the pipe. On the other hand, a biconcave discoid particle moves along a helical path around the center of the pipe with periodic oscillations in its orientation. The radius of the helical path and the polar angle of the orientation increase as the hollow of the concave becomes larger.

  14. Influence of coal slurry particle composition on pipeline hydraulic transportation behavior

    Science.gov (United States)

    Li-an, Zhao; Ronghuan, Cai; Tieli, Wang

    2018-02-01

    Acting as a new type of energy transportation mode, the coal pipeline hydraulic transmission can reduce the energy transportation cost and the fly ash pollution of the conventional coal transportation. In this study, the effect of average velocity, particle size and pumping time on particle composition of coal particles during hydraulic conveying was investigated by ring tube test. Meanwhile, the effects of particle composition change on slurry viscosity, transmission resistance and critical sedimentation velocity were studied based on the experimental data. The experimental and theoretical analysis indicate that the alter of slurry particle composition can lead to the change of viscosity, resistance and critical velocity of slurry. Moreover, based on the previous studies, the critical velocity calculation model of coal slurry is proposed.

  15. Effect of Particle Concentration on Ablation Behavior of Carbon/Carbon Composites

    Directory of Open Access Journals (Sweden)

    ZHA Bai-lin

    2016-07-01

    Full Text Available A self-designed oxygen-kerosene ablation system was employed to study the ablation mechanism and performance of the carbon-carbon composites. Particle concentrations of the gas-solid two-phase ablation flow were 0, 1.37%, 2.22%, and 2.64% respectively. The microstructure of post-test samples was analysed through the scanning electron microscope (SEM, and the ablation rate was calculated. The influence principle of particle concentrations on the ablation rate of the carbon-carbon composites was studied, and the mechanism of ablation was analysed. Experiment results show that with no particles involved the mass ablation rate is 0.159g/s and the linear ablation rate is 0.175mm/s, while with particles introduced, the minimum mass ablation rate and linear ablation rate are 0.432g/s and 0.843mm/s respectively, with the increase of particle concentrations, the ablation rate becomes accelerated. Particle erosion makes the ablation of sample seriously intensified, and the ablation gradient of radial fiber on erosion surface is increased with the increase of particle concentrations as well.

  16. Influence of Particle Phase Morphology on the Hygroscopic Behavior of Atmospheric Aerosols

    Science.gov (United States)

    Hodas, N.; Zuend, A.; Flagan, R. C.; Seinfeld, J.

    2014-12-01

    While current models generally treat organic and mixed organic-inorganic aerosol particles as well-mixed liquids, these particles can exist in multiple phase states depending on their chemical composition and on ambient conditions such as relative humidity (RH). For example, multi-component particles can undergo phase separations in which an inorganic-electrolyte-rich phase and an organic-rich phase coexist within one particle. Organic aerosols have been shown to exist in an amorphous, highly viscous semi-solid state under atmospherically relevant conditions. Hygroscopic growth factors (GFs) of ten laboratory-generated, organic-inorganic aerosol systems with phase morphologies ranging from well-mixed liquids, to phase-separated particles, to viscous semi-solids were measured with the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe at RH values ranging from 30 - 90%. Measured GFs were compared to water-uptake calculations in which it was assumed that particles could be represented as thermodynamically ideal, well-mixed liquids, as well as those predicted by the Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model. Both ideal and AIOMFAC-predicted GFs were in good agreement with experimental GFs for aerosol systems that exist as well-mixed liquids across the range of RHs tested; however, substantial disagreement between experimental and ideal GFs was observed for phase-separated particles. This disagreement was greatest at low to moderate RHs, whereas experimental GFs approached the ideal curve at high RH as phase-separated particles merged to a single phase with increased water content. AIOMFAC, which offers the ability to predict liquid-liquid and liquid-solid phase separations within a thermodynamic equilibrium computation, was within 10% of experimental GFs at all RHs for all aerosol systems. The assumption that water uptake is driven by ideal, equilibrium partitioning leads to errors in calculated particle

  17. Investigation of the Anisotropic Behavior of Wood Char Particles during Gasification

    DEFF Research Database (Denmark)

    Henriksen, Ulrik Birk; Hindsgaul, Claus; Qvale, Einar Bjørn

    2006-01-01

    (R) and tangential (T) directions. Despite this, this property has normally not been included in mathematical model descriptions of gasification of thermally thick particles. The present paper describes a study of the influence of the anisotropy on the reactivity of thermally thick char particles...... of the normal to the greater surface of the slabs L, R, or T (see Figure 8). When the smaller surfaces were coated with alumina silicate, the gasification agent could only enter the interior of the slabs through the greater surfaces. Thermally thick char particles from beech and pine reacted more slowly...

  18. An association rule mining-based framework for understanding lifestyle risk behaviors.

    Directory of Open Access Journals (Sweden)

    So Hyun Park

    Full Text Available OBJECTIVES: This study investigated the prevalence and patterns of lifestyle risk behaviors in Korean adults. METHODS: We utilized data from the Fourth Korea National Health and Nutrition Examination Survey for 14,833 adults (>20 years of age. We used association rule mining to analyze patterns of lifestyle risk behaviors by characterizing non-adherence to public health recommendations related to the Alameda 7 health behaviors. The study variables were current smoking, heavy drinking, physical inactivity, obesity, inadequate sleep, breakfast skipping, and frequent snacking. RESULTS: Approximately 72% of Korean adults exhibited two or more lifestyle risk behaviors. Among women, current smoking, obesity, and breakfast skipping were associated with inadequate sleep. Among men, breakfast skipping with additional risk behaviors such as physical inactivity, obesity, and inadequate sleep was associated with current smoking. Current smoking with additional risk behaviors such as inadequate sleep or breakfast skipping was associated with physical inactivity. CONCLUSION: Lifestyle risk behaviors are intercorrelated in Korea. Information on patterns of lifestyle risk behaviors could assist in planning interventions targeted at multiple behaviors simultaneously.

  19. Integrating Norm Activation Model and Theory of Planned Behavior to Understand Sustainable Transport Behavior: Evidence from China

    Directory of Open Access Journals (Sweden)

    Yuwei Liu

    2017-12-01

    Full Text Available With increasing urbanization in China, many cities are facing serious environmental problems due to continuous and substantial increase in automobile transportation. It is becoming imperative to examine effective ways to reduce individual automobile use to facilitate sustainable transportation behavior. Empirical, theory-based research on sustainable transportation in China is limited. In this research, we propose an integrated model based on the norm activation model and the theory of planned behavior by combining normative and rational factors to predict individuals’ intention to reduce car use. Data from a survey of 600 car drivers in China’s three metropolitan areas was used to test the proposed model and hypotheses. Results showed that three variables, perceived norm of car-transport reduction, attitude towards reduction, and perceived behavior control over car-transport reduction, significantly affected the intention to reduce car-transport. Personal norms mediated the relationship between awareness of consequences of car-transport, ascription of responsibility of car-transport, perceived subjective norm for car-transport reduction, and intention to reduce car-transport. The results of this research not only contribute to theory development in the area of sustainable transportation behavior, but also provide a theoretical frame of reference for relevant policy-makers in urban transport management.

  20. Understanding Physical Activity Behavior in African American and Caucasian College Students: An Application of the Theory of Planned Behavior

    Science.gov (United States)

    Blanchard, Chris; Fisher, Janet; Sparling, Phil; Nehl, Erich; Rhodes, Ryan; Courneya, Kerry; Baker, Frank

    2008-01-01

    Only 30% of college students meet the recommended amount of physical activity (PA) for health benefits, and this number is lower for African American students. Moreover, the correlates of PA may vary by ethnicity. Objective: In the present study, the authors tested the utility of the theory of planned behavior for explaining PA intentions and…

  1. Understanding strength exercise intentions and behavior in hematologic cancer survivors: an analysis of the intention-behavior gap.

    Science.gov (United States)

    Vallerand, James R; Rhodes, Ryan E; Walker, Gordon J; Courneya, Kerry S

    2016-12-01

    Strength exercise improves many health outcomes in cancer survivors but the prevalence and correlates of strength exercise have not been well-described. Moreover, no study has examined the critical intention-behavior gap for exercise in cancer survivors. The aims of this study are to quantify the intention-behavior gap for strength exercise in hematologic cancer survivors (HCS) and examine correlates of both intention formation and translation using the multi-process action control framework (M-PAC). A random sample of 2100 HCS in Alberta, Canada, were mailed a survey assessing strength exercise behavior, the M-PAC, and demographic/medical variables. Separate logistic regressions were used to analyze the relationships between the correlates and intention formation and translation. Surveys were completed by 606 HCS with 58 % (n = 353) intending to do strength exercise. HCS who were not retired (OR = 1.56, p = 0.001), were highly educated (OR = 1.32, p = 0.001), and had a favorable attitude (OR = 1.56, p exercise intention. Of those with an exercise intention, 51 % (n = 181) reported regular strength exercise. HCS with a detailed plan (OR = 1.86, p strength exercise and only half of intenders translated that intention into behavior. Interventions targeting both intention formation and translation may provide the best approach for increasing strength exercise in HCS.

  2. Integrating Norm Activation Model and Theory of Planned Behavior to Understand Sustainable Transport Behavior: Evidence from China.

    Science.gov (United States)

    Liu, Yuwei; Sheng, Hong; Mundorf, Norbert; Redding, Colleen; Ye, Yinjiao

    2017-12-18

    With increasing urbanization in China, many cities are facing serious environmental problems due to continuous and substantial increase in automobile transportation. It is becoming imperative to examine effective ways to reduce individual automobile use to facilitate sustainable transportation behavior. Empirical, theory-based research on sustainable transportation in China is limited. In this research, we propose an integrated model based on the norm activation model and the theory of planned behavior by combining normative and rational factors to predict individuals' intention to reduce car use. Data from a survey of 600 car drivers in China's three metropolitan areas was used to test the proposed model and hypotheses. Results showed that three variables, perceived norm of car-transport reduction, attitude towards reduction, and perceived behavior control over car-transport reduction, significantly affected the intention to reduce car-transport. Personal norms mediated the relationship between awareness of consequences of car-transport, ascription of responsibility of car-transport, perceived subjective norm for car-transport reduction, and intention to reduce car-transport. The results of this research not only contribute to theory development in the area of sustainable transportation behavior, but also provide a theoretical frame of reference for relevant policy-makers in urban transport management.

  3. Applying Self-Efficacy Theory to Understanding the Behavioral Expectations of College Students with Disabilities in Requesting Accommodations

    Science.gov (United States)

    Snitker-Magin, Mikael C.

    2010-01-01

    The purpose of the study was to apply Bandura's self-efficacy theory to understanding the behavior of college students with disabilities in requesting accommodations. Students with disabilities were recruited from 20 two-year and four-year postsecondary institutions by asking student disabilities services staff to forward an email invitation to…

  4. Understanding the Personality and Behavioral Mechanisms Defining Hypersexuality in Men Who Have Sex With Men.

    Science.gov (United States)

    Miner, Michael H; Romine, Rebecca Swinburne; Raymond, Nancy; Janssen, Erick; MacDonald, Angus; Coleman, Eli

    2016-09-01

    Hypersexuality has been conceptualized as sexual addiction, compulsivity, and impulsivity, among others, in the absence of strong empirical data in support of any specific conceptualization. To investigate personality factors and behavioral mechanisms that are relevant to hypersexuality in men who have sex with men. A sample of 242 men who have sex with men was recruited from various sites in a moderate-size mid-western city. Participants were assigned to a hypersexuality group or a control group using an interview similar to the Structured Clinical Interview for the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition. Self-report inventories were administered that measured the broad personality constructs of positive emotionality, negative emotionality, and constraint and more narrow constructs related to sexual behavioral control, behavioral activation, behavioral inhibition, sexual excitation, sexual inhibition, impulsivity, attention-deficit/hyperactivity disorder, and sexual behavior. Hierarchical logistic regression was used to determine the relation between these personality and behavioral variables and group membership. A hierarchical logistic regression controlling for age showed a significant positive relation between hypersexuality and negative emotionality and a negative relation with constraint. None of the behavioral mechanism variables entered this equation. However, a hierarchical multiple regression analysis predicting sexual behavioral control indicated that lack of such control was positively related to sexual excitation and sexual inhibition owing to the threat of performance failure and negatively related to sexual inhibition owing to the threat of performance consequences and general behavioral inhibition Hypersexuality was found to be related to two broad personality factors that are characterized by emotional reactivity, risk taking, and impulsivity. The associated lack of sexual behavior control is influenced by sexual

  5. Electrokinetics and behavior near the interface of colloidal particles in non-polar dispersions.

    Science.gov (United States)

    Prasad, Manoj; Strubbe, Filip; Beunis, Filip; Neyts, Kristiaan

    2017-08-23

    The electrokinetics and charging of nonpolar colloidal dispersions subjected to a voltage are investigated by electric current and optical measurements. From electric current measurements in response to an alternating triangular voltage with a peak value of a few hundred volts, we find that polystyrene toner particles are compacted near the electrodes and their charge increases by more than a factor of 20. The important increase of charge is interpreted by a mechanism in which counter charges, which are originally at the particle surface, are desorbed. Optical measurements performed under a dc voltage of the order of a few hundred volts demonstrate that the charge of the particles can again decrease or even be inverted. These phenomena are attributed to the movement of counter charged species from the interface layers onto the surface of the particles. The findings of this study are relevant for electrophoretic displays and liquid toner printing.

  6. Electrochemical behavior of zinc particles with silica based coatings as anode material for zinc air batteries with improved discharge capacity

    Science.gov (United States)

    Schmid, M.; Willert-Porada, M.

    2017-05-01

    Silica coatings on zinc particles as anode material for alkaline zinc air batteries are expected to reduce early formation of irreversible ZnO passivation layers during discharge by controlling zinc dissolution and precipitation of supersaturated zincates, Zn(OH)42-. Zinc particles were coated with SiO2 (thickness: 15 nm) by chemical solution deposition and with Zn2SiO4 (thickness: 20 nm) by chemical vapor deposition. These coatings formed a Si(OH)4 gel in aqueous KOH and retarded hydrogen evolution by 40%. By treatment in aqueous KOH and drying afterwards, the silica coatings were changed into ZnO-K2O·SiO2 layers. In this work, the electrochemical performance of such coated zinc particles is investigated by different electrochemical methods in order to gain a deeper understanding of the mechanisms of the coatings, which reduce zinc passivation. In particular, zinc utilization and changes in internal resistance are investigated. Moreover, methods for determination of diffusion coefficients, charge carrier numbers and activation energies for electrochemical oxidation are determined. SiO2-coated zinc particles show improved discharge capacity (CVD-coated zinc: 69% zinc utilization, CSD-coated zinc: 62% zinc utilization) as compared to as-received zinc (57% zinc utilization) at C/20 rate, by reducing supersaturation of zincates. Additionally, KOH-modified SiO2-coated zinc particles enhance rechargeability after 100% depth-of-discharge.

  7. Effect of particle morphology on the mechanical and thermo-mechanical behavior of polymer composites

    OpenAIRE

    Oréfice, R. L.; Hench, L. L.; Brennan, A. B.

    2001-01-01

    Fiber reinforced polymer composites have been used in many applications, such as in automobile, aerospace and naval industries, due basically to their high strength-to-weight and modulus-to-weight, among other properties. Even though particles are usually not able to lead to the level of reinforcement of fibers, particle reinforced polymer composites have been proposed for many new applications due to their low cost, easy fabrication and isotropic properties. In this work, polymer composites ...

  8. Modulation of mesenchymal stem cell behavior by nano- and micro-sized β-tricalcium phosphate particles in suspension and composite structures

    Science.gov (United States)

    Smoak, Mollie; Hogan, Katie; Kriegh, Lisa; Chen, Cong; Terrell, LeKeith B.; Qureshi, Ammar T.; Todd Monroe, W.; Gimble, Jeffrey M.; Hayes, Daniel J.

    2015-04-01

    Interest has grown in the use of microparticles and nanoparticles for modifying the mechanical and biological properties of synthetic bone composite structures. Micro- and nano-sized calcium phosphates are of interest for their osteoinductive behavior. Engineered composites incorporating polymers and ceramics, such as poly-l-lactic acid (PLLA) and beta-tricalcium phosphate (β-TCP), for bone tissue regeneration have been well investigated for their proliferative and osteoinductive abilities. Only limited research has been done to investigate the effects of different sizes of β-TCP particles on human mesenchymal stromal cell behavior. As such, the aim of this study was to investigate the modulations of human adipose-derived stem cell (hASCs) behavior within cell/particle and cell/composite systems as functions of particle size, concentration, and exposure time. The incorporation of nanoscale calcium phosphate resulted in improved mechanical properties and osteogenic behavior within the scaffold compared to the microscale calcium phosphate additives. Particle exposure results indicate that cytotoxicity on hASCs correlates inversely with particle size and increases with the increasing exposure time and particle concentration. Composites with increasing β-TCP content, whether microparticles or nanoparticles, were less toxic than colloidal micro- and nano-sized β-TCP particles directly supplied to hASCs. The difference in viability observed as a result of varying exposure route is likely related to the increased cell-particle interactions in the direct exposure compared to the particles becoming trapped within the scaffold/polymer matrix.

  9. Behavior of Particle Depots in Molten Silicon During Float-Zone Growth in Strong Magnetic Fields

    Science.gov (United States)

    Jauss, T.; Croell, A.; SorgenFrei, T.; Azizi, M.; Reimann, C.; Friedrich, J.; Volz, M. P.

    2014-01-01

    Solar cells made from directionally solidified silicon cover 57% of the photovoltaic industry's market [1]. One major issue during directional solidification of silicon is the precipitation of foreign phase particles. These particles, mainly SiC and Si3N4, are precipitated from the dissolved crucible coating, which is made of silicon nitride, and the dissolution of carbon monoxide from the furnace atmosphere. Due to their hardness and size of several hundred micrometers, those particles can lead to severe problems during the wire sawing process for wafering the ingots. Additionally, SiC particles can act as a shunt, short circuiting the solar cell. Even if the particles are too small to disturb the wafering process, they can lead to a grit structure of silicon micro grains and serve as sources for dislocations. All of this lowers the yield of solar cells and reduces the performance of cells and modules. We studied the behaviour of SiC particle depots during float-zone growth under an oxide skin, and strong static magnetic fields. For high field strengths of 3T and above and an oxide layer on the sample surface, convection is sufficiently suppressed to create a diffusive like regime, with strongly dampened convection [2, 3]. To investigate the difference between atomically rough phase boundaries and facetted growth, samples with [100] and [111] orientation were processed.

  10. Understanding work-related social media use: An extension of theory of planned behavior.

    NARCIS (Netherlands)

    van Zoonen, W.; Verhoeven, J.W.M.; Elving, W.J.L.

    2014-01-01

    This study examines the motives of employees to engage in work related social media use - i.e. the use of personal social media accounts to communicate about work-related issues. The theory of planned behavior (TPB) was used to explain this behavior. Because social media can enable users to express

  11. Understanding mechanisms of change in the development of antisocial behavior: The impact of a universal intervention

    NARCIS (Netherlands)

    P.A.C. van Lier (Pol); P. Vuijk (Patricia); A.A.M. Crijnen (Alfons)

    2005-01-01

    textabstractThe association between the development of antisocial behavior, affiliation with deviant friends, and peer rejection was tested with a preventive intervention; 664 boys and girls were randomly assigned to a universal classroom-based intervention targeting disruptive behavior or a control

  12. Chemical approaches to understanding the environmental behavior of Pu, Np, and Tc

    International Nuclear Information System (INIS)

    Bondietti, E.A.

    1978-01-01

    Some topics discussed are as follows: speciation behavior of Pu, Np, and Tc; thermodynamic and radiochemical behavior; sorption studies with soils; Pu oxidation states in fresh water; Np oxidation states in soils; effect of oxidation state of Tc on environmental transport predictions; and thermodynamic calculations of Tc speciation

  13. Parental Cognitions, Parental Behavior, and the Child's Understanding of the Parent-Child Relationship.

    Science.gov (United States)

    Dekovic, Maja; And Others

    1991-01-01

    Studied the relationship of parental reasoning complexity to parental behavior during parent-child interactions, and the effect of this relationship on children's social cognitions. Results indicate that parental reasoning complexity is related to parental behaviors of restrictive control, authoritative control, and support, which, in turn, are…

  14. Understanding Soccer Team Supporters' Behavior and Culture in a Globalized Society from Social Learning Theory

    Science.gov (United States)

    Lee, Seungbum; Han, Keunsu

    2012-01-01

    Whereas there have been many academic studies on European soccer team supporters, relatively few studies have looked at supporters in Asia, especially regarding their supporting behavior and culture. Broadly, the purpose of this paper is to describe the behavior and culture of supporters of the Korean professional soccer league (K-League).…

  15. Harsh Parenting, Deviant Peers, Adolescent Risky Behavior: Understanding the Meditational Effect of Attitudes and Intentions.

    Science.gov (United States)

    Neppl, Tricia K; Dhalewadikar, Jui; Lohman, Brenda J

    2016-09-01

    Although research supports the influence of parents and peers on adolescent risky behavior, less is known about mechanisms proposed to explain this relation. This study examined the influence of adolescent attitudes and intentions about such behaviors. Prospective, longitudinal data came from rural youth who participated throughout adolescence (n= 451). Observed harsh parenting and relationship with deviant peers was assessed in early adolescence, attitudes and intentions were measured during middle adolescence, and risky behavior was assessed in late adolescence. Results indicated that parenting and deviant peers was related to engagement in tobacco use, alcohol use, and risky sexual behaviors. Moreover, attitudes and intentions mediated this relationship even after parent use and adolescent early involvement in these behaviors were taken into account.

  16. Understanding the self-assembly process and behavior of metal-seamed pyrogallol[4]arene nanocapsules

    Science.gov (United States)

    Mossine, Andrew V.

    time of measurement as well as the solvent system during synthesis were also performed. Furthermore, SANS was also used to study Fe3+-PgC complexes. These complexes are difficult if not impossible to crystallize, and therefore cannot be studied using scXRD. SANS was used in conjunction with elemental analysis to deduce a structure for these materials. In addition to understanding the synthesis of MONCs, another goal was to also use them for other (possibly practical) purposes. To this end, PgC-based MONCs were used as building blocks in metal-organic frameworks (MOFs). This involved the use of divergent ligands to "link" capsular monomers together, resulting in one and two dimensional frameworks. This work not only produced functional materials that may be useful in future research efforts, but also showed that exo-ligand exchange can be used to derivatize MONCs into potentially useful and functional materials. The introduction of radioisotopes into the nanocapsule was another method by which functionality could theoretically be imparted into MONCs. It was envisioned that MONCs could potentially be used as carrier systems for radioisotopes, and thereby function as agents for therapy or medical imaging. Copper hexamers constructed from 64Cu2+ were therefore prepared and studied in a living system. However, these studies were unsuccessful at showing that the copper-seamed MONCs differed in behavior from 64Cu in vivo, either due to poor labeling efficiency or metabolism. Nevertheless, radiolabeling of hexameric nanocapsules was helpful in broadening our understanding of these materials. Some of the studies that were conducted include those that gauge the solubility and stability of nanocapsules, as well as others that explore the conditions required for cationic uptake and exchange.

  17. Medical Drama Viewing and Healthy Lifestyle Behaviors: Understanding the Role of Health Locus of Control Beliefs and Education Level.

    Science.gov (United States)

    Kim, Sungsu; Baek, Young Min

    2017-11-22

    The present study advances the understanding of how medical drama viewing influences healthy lifestyle behaviors (e.g., smoking, exercising, and consuming vegetables) by examining the role of the health locus of control (HLOC) beliefs and education level. An analysis of nationally representative data reveals that watching medical dramas is positively associated with chance and powerful others' HLOC beliefs. In addition, healthy lifestyle behaviors are positively associated with the internal HLOC belief and are negatively associated with the chance and powerful others' HLOC beliefs. Research findings demonstrate that there are indirect effects of medical drama viewing on these behaviors via chance and powerful others' HLOC beliefs. The indirect effect through the powerful others' HLOC belief is also contingent on the education level. The implications for the role of HLOC beliefs and education level in terms of the effects of medical dramas on health-promoting behaviors are discussed.

  18. Application of synchrotron radiation X-ray computed tomography to investigate the agglomerating behavior of TiB{sub 2} particles in aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fei; Mao, Feng; Chen, Zongning; Han, Jingyu; Yan, Guangyuan [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Tongmin, E-mail: tmwang@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Cao, Zhiqiang, E-mail: caozq@dlut.edu.cn [Laboratory of Special Processing of Raw Materials, Dalian University of Technology, Dalian 116024 (China)

    2015-02-15

    Highlights: • SR-CT was a powerful tool to investigate the TiB{sub 2} distribution in Al-TiB{sub 2} in situ composites. • Three kinds of agglomerations frequently present in the composites. • Agglomerations formed via the diffused atoms reacting with intermediate products. • The composites containing agglomerations show a much reduced ductility. - Abstract: Agglomeration of reinforcing particles has a number of deleterious effects on the properties of in situ metal matrix composites (MMCs). In order to better understand this phenomenon, the agglomerating behavior of TiB{sub 2} particles in aluminum based in situ MMCs was investigated using synchrotron radiation X-ray computed tomography (SR-CT) and field emission scanning electron microscope (FESEM). SR-CT was shown to be a powerful tool for visualizing and quantifying the three-dimensional (3D) features within the composites. Based on the SR-CT and FESEM results, a formation mechanism of the flaky agglomerates, flocculent agglomerates and clusters of coarse TiB{sub 2} particles, which are most frequently presented in the in situ Al/TiB{sub 2} composite, has been proposed. The mechanism shows that the formation of these three kinds of agglomerates can be attributed to three parallel processes, i.e. diffusing titanium atoms reacting with AlB{sub 2}, aluminum melt directly reacting with emulsified salt, diffusing boron atoms reacting with TiAl{sub 3}, respectively. Moreover, the mechanism may shed some light on how to design better processing techniques for obtaining homogenous particle distribution in in situ Al/TiB{sub 2} composites in the future.

  19. Application of synchrotron radiation X-ray computed tomography to investigate the agglomerating behavior of TiB2 particles in aluminum

    International Nuclear Information System (INIS)

    Chen, Fei; Mao, Feng; Chen, Zongning; Han, Jingyu; Yan, Guangyuan; Wang, Tongmin; Cao, Zhiqiang

    2015-01-01

    Highlights: • SR-CT was a powerful tool to investigate the TiB 2 distribution in Al-TiB 2 in situ composites. • Three kinds of agglomerations frequently present in the composites. • Agglomerations formed via the diffused atoms reacting with intermediate products. • The composites containing agglomerations show a much reduced ductility. - Abstract: Agglomeration of reinforcing particles has a number of deleterious effects on the properties of in situ metal matrix composites (MMCs). In order to better understand this phenomenon, the agglomerating behavior of TiB 2 particles in aluminum based in situ MMCs was investigated using synchrotron radiation X-ray computed tomography (SR-CT) and field emission scanning electron microscope (FESEM). SR-CT was shown to be a powerful tool for visualizing and quantifying the three-dimensional (3D) features within the composites. Based on the SR-CT and FESEM results, a formation mechanism of the flaky agglomerates, flocculent agglomerates and clusters of coarse TiB 2 particles, which are most frequently presented in the in situ Al/TiB 2 composite, has been proposed. The mechanism shows that the formation of these three kinds of agglomerates can be attributed to three parallel processes, i.e. diffusing titanium atoms reacting with AlB 2 , aluminum melt directly reacting with emulsified salt, diffusing boron atoms reacting with TiAl 3 , respectively. Moreover, the mechanism may shed some light on how to design better processing techniques for obtaining homogenous particle distribution in in situ Al/TiB 2 composites in the future

  20. Understanding Irrigator Bidding Behavior in Australian Water Markets in Response to Uncertainty

    Directory of Open Access Journals (Sweden)

    Alec Zuo

    2014-11-01

    Full Text Available Water markets have been used by Australian irrigators as a way to reduce risk and uncertainty in times of low water allocations and rainfall. However, little is known about how irrigators’ bidding trading behavior in water markets compares to other markets, nor is it known what role uncertainty and a lack of water in a variable and changing climate plays in influencing behavior. This paper studies irrigator behavior in Victorian water markets over a decade (a time period that included a severe drought. In particular, it studies the evidence for price clustering (when water bids/offers end mostly around particular numbers, a common phenomenon present in other established markets. We found that clustering in bid/offer prices in Victorian water allocation markets was influenced by uncertainty and strategic behavior. Water traders evaluate the costs and benefits of clustering and act according to their risk aversion levels. Water market buyer clustering behavior was mostly explained by increased market uncertainty (in particular, hotter and drier conditions, while seller-clustering behavior is mostly explained by strategic behavioral factors which evaluate the costs and benefits of clustering.

  1. Evaluation of the long-term corrosion behavior of dental amalgams: influence of palladium addition and particle morphology.

    Science.gov (United States)

    Colon, Pierre; Pradelle-Plasse, Nelly; Galland, Jacques

    2003-05-01

    The purpose of this investigation was to evaluate the long-term corrosion behavior of experimental amalgams as a function of particle morphology and palladium content. Samples of four experimental high copper amalgams were prepared according to ADA specifications. Two of them had the same chemical composition but one had lathe cut particles (LCP) and the other had spherical particles (SP). The two others had spherical powders with an addition of 0.5 wt% of palladium (SP 0.5) and 1 wt% of palladium(SP 1) for the other. Corrosion resistance was evaluated by electrochemical techniques in Ringer's solution in a thermostated cell at 37 degrees C for samples aged 5, 8, 12, 16 months and 10 years. Potentiokinetic curves were drawn and the potential and the current density corresponding to the first anodic peak were registered. For all the amalgam samples the corrosion behavior improves over the 10-year period. SP samples exhibit a better behavior than LCP. Palladium addition improves corrosion behavior as compared to samples without palladium. No real difference is found regarding the amount of palladium between 0.5 and 1%. The potentials progress from a range between 0 and 20 mV/SCE to a range of 60-80 after 10 years. The stabilization of the potential begins after only 16 months. Except for the LCP, all the values converge to the same level of 80 mV/SCE. The addition of no more than 0.5 wt% Palladium in a high copper amalgam powder improves the corrosion behavior of the amalgam up to a period of 10 years. The potential of the first anodic peak increases for each amalgam, probably in relation to the evolution of the structure of the material. Clinically, it is of interest to consider the good electrochemical behavior of older restorations when contemplating the repair or replacement of such fillings. At the same time, galvanic current can occur when a new amalgam restoration is placed in contact with an old one even if the same amalgam is used. In this situation, the new

  2. Particle behavior of the φ6 kinks in an external potential compared and contrasted with classical behavior

    Directory of Open Access Journals (Sweden)

    N Riazi

    2011-03-01

    Full Text Available   In this paper, we study particle aspects of the φ6 kinks in an external potential. The external potential is implemented by breaking the translational invariance of the system. The dynamics of the kink is calculated for the simple harmonic oscillator (SHO and barrier potentials. The periodic motion of the kink in the SHO case is compared to the corresponding ordinary (classical motion. It is found that for small amplitude oscillations, considerable deviation from the conventional SHO motion happens. As for the barrier potential, it is found that tunneling happens if barriers are thin enough. The tunneling time is calculated as a function of the barrier width.

  3. Sandblasting as a surface modification technique on titanium alloys for biomedical applications: abrasive particle behavior

    International Nuclear Information System (INIS)

    Balza, J C; Zujur, D; Delvasto, P; Gil, L; Subero, R; Dominguez, E; Alvarez, J

    2013-01-01

    The present work shows the analysis of a sandblasting process using alumina abrasive particles on Ti-6Al-4V surfaces. The metallic samples were first characterized by optical microscopy (OM), revealing an α+β microstructure with a Widmanstätten morphology. Topography of the samples was assessed by scanning electron microscopy (SEM), before and after sandblasting. The Al 2 O 3 particles used had a granulometric distribution between 420 and 850 μm, with a median particle size (d50) of 670 μm, which decreased to 420 μm after sandblasting for 10 seconds. This change in the size of the particles generated a loss on particle kinetic energy by a factor of 3.5. Such variation on processing conditions induced a progressive increase on average roughness (Ra) of the Ti-6Al-4V surfaces, until the first 7 seconds were reached. From that point on, a reverse process was observed, exerting a polishing effect on the surface of the Ti-6Al-4V alloy.

  4. Temperature and Particle Size Influence on the High Cycle Fatigue Behavior of the SiC Reinforced 2124 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Lisa Winter

    2018-01-01

    Full Text Available In this work the high cycle fatigue behavior of a particulate reinforced 2124 aluminum alloy, manufactured by powder metallurgy, is investigated. SiC particles with a size of 3 μm and 300 nm and a volume fraction of 5 and 25 vol %, respectively, were used as reinforcement component. The present study is focused on the fatigue strength and the influence of particle size and temperature. Systematic work is done by comparing the unreinforced alloy and the reinforced conditions. All of the material conditions are characterized by electron microscopy and tensile and fatigue testing at room temperature and at 180 °C. With an increase in temperature the tensile and the fatigue strength decrease, regardless of particle size and volume fraction due to the lower matrix strength. The combination of 25 vol % SiC particle fraction with 3 μm size proved to be most suitable to achieve a major fatigue performance at room temperature and at 180 °C. The fatigue strength is increased by 40% when compared to the unreinforced alloy, as it is assumed the interparticle spacing for this condition reaches a critical value then.

  5. Do behavioral scientists really understand HIV-related sexual risk behavior? A systematic review of longitudinal and experimental studies predicting sexual behavior.

    Science.gov (United States)

    Huebner, David M; Perry, Nicholas S

    2015-10-01

    Behavioral interventions to reduce sexual risk behavior depend on strong health behavior theory. By identifying the psychosocial variables that lead causally to sexual risk, theories provide interventionists with a guide for how to change behavior. However, empirical research is critical to determining whether a particular theory adequately explains sexual risk behavior. A large body of cross-sectional evidence, which has been reviewed elsewhere, supports the notion that certain theory-based constructs (e.g., self-efficacy) are correlates of sexual behavior. However, given the limitations of inferring causality from correlational research, it is essential that we review the evidence from more methodologically rigorous studies (i.e., longitudinal and experimental designs). This systematic review identified 44 longitudinal studies in which investigators attempted to predict sexual risk from psychosocial variables over time. We also found 134 experimental studies (i.e., randomized controlled trials of HIV interventions), but of these only 9 (6.7 %) report the results of mediation analyses that might provide evidence for the validity of health behavior theories in predicting sexual behavior. Results show little convergent support across both types of studies for most traditional, theoretical predictors of sexual behavior. This suggests that the field must expand the body of empirical work that utilizes the most rigorous study designs to test our theoretical assumptions. The inconsistent results of existing research would indicate that current theoretical models of sexual risk behavior are inadequate, and may require expansion or adaptation.

  6. Racial Bias in Drivers' Yielding Behavior at Crosswalks : Understanding the Effect

    Science.gov (United States)

    2017-10-01

    This project explores social identity factors (race and gender) that influence drivers' behavior in interactions with pedestrians at crosswalks. One dangerous potential point of conflict for pedestrians within the transportation system is interaction...

  7. Understanding adolescent peer sexual harassment and abuse: using the theory of planned behavior.

    Science.gov (United States)

    Li, Man Yu; Frieze, Irene; Tang, Catherine So-kum

    2010-06-01

    This study examines intentions to take protective action against peer sexual harassment and abuse (PSHA). The theory of planned behavior (TPB) proposes that attitudes about protective action, perceptions of what others would think about doing this (subjective norms), and behavioral control would be important predictors. A total of 1,531 Chinese secondary school students (769 boys and 762 girls) from Hong Kong were surveyed to test this model. Results showed that the TPB model was predictive for girls, but only subjective norms and behavioral control significantly predicted boys' intentions to protect themselves. Results supported the influence of subjective norms and perceived behavioral control on youths' intentions to reject PSHA. These factors may be useful in guiding the development of an educational program for prevention of PSHA.

  8. A Better Understanding of Parental Emotional Socialization Behaviors With an Illustrative Context

    OpenAIRE

    Kılıç, Şükran

    2014-01-01

    The goal of this study is to provide an illustrative framework for synthesizing derived from a growing body of crucial studies on parental emotional socialization behaviors and processes with regard to children’s emotional competence. This explanatory perspective has also been tried to be established with other relevant parental characteristics. Explaining the parental emotional socialization behaviors are firstly established upon the parental styles which is one of the basic conc...

  9. Travel Behavior Change in Older Travelers: Understanding Critical Reactions to Incidents Encountered in Public Transport

    Directory of Open Access Journals (Sweden)

    Catherine Sundling

    2015-11-01

    Full Text Available Accessibility of travel may be better understood if psychological factors underlying change in travel behavior are known. This paper examines older (65+ travelers’ motives for changing their travel behavior. These changes are grounded in critical incidents earlier encountered in public-transport travel. A scientific framework is developed based on cognitive and behavioral theory. In 29 individual interviews, travelers’ critical reactions (i.e., cognitive, emotional, and/or behavioral to 77 critical incidents were examined. By applying critical incident technique (CIT, five reaction themes were identified that had generated travel-behavior change: firm restrictions, unpredictability, unfair treatment, complicated trips, and earlier adverse experiences. To improve older travelers’ access to public transport, key findings were: (a service must be designed so as to strengthen the feeling of being in control throughout the journey; (b extended personal service would increase predictability in the travel chain and decrease travel complexity; consequently, (c when designing new services and making effective accessibility interventions, policy makers should consider and utilize underlying psychological factors that could direct traveler behavior.

  10. Travel Behavior Change in Older Travelers: Understanding Critical Reactions to Incidents Encountered in Public Transport.

    Science.gov (United States)

    Sundling, Catherine

    2015-11-18

    Accessibility of travel may be better understood if psychological factors underlying change in travel behavior are known. This paper examines older (65+) travelers' motives for changing their travel behavior. These changes are grounded in critical incidents earlier encountered in public-transport travel. A scientific framework is developed based on cognitive and behavioral theory. In 29 individual interviews, travelers' critical reactions (i.e., cognitive, emotional, and/or behavioral) to 77 critical incidents were examined. By applying critical incident technique (CIT), five reaction themes were identified that had generated travel-behavior change: firm restrictions, unpredictability, unfair treatment, complicated trips, and earlier adverse experiences. To improve older travelers' access to public transport, key findings were: (a) service must be designed so as to strengthen the feeling of being in control throughout the journey; (b) extended personal service would increase predictability in the travel chain and decrease travel complexity; consequently, (c) when designing new services and making effective accessibility interventions, policy makers should consider and utilize underlying psychological factors that could direct traveler behavior.

  11. Influence of Sludge Particles on the Fatigue Behavior of Al-Si-Cu Secondary Aluminium Casting Alloys

    Directory of Open Access Journals (Sweden)

    Lorella Ceschini

    2018-04-01

    Full Text Available Al-Si-Cu alloys are the most widely used materials for high-pressure die casting processes. In such alloys, Fe content is generally high to avoid die soldering issues, but it is considered an impurity since it generates acicular intermetallics (β-Fe which are detrimental to the mechanical behavior of the alloys. Mn and Cr may act as modifiers, leading to the formation of other Fe-bearing particles which are characterized by less harmful morphologies, and which tend to settle on the bottom of furnaces and crucibles (usually referred to as sludge. This work is aimed at evaluating the influence of sludge intermetallics on the fatigue behavior of A380 Al-Si-Cu alloy. Four alloys were produced by adding different Fe, Mn and Cr contents to A380 alloy; samples were remelted by directional solidification equipment to obtain a fixed secondary dendrite arm spacing (SDAS value (~10 μm, then subjected to hot isostatic pressing (HIP. Rotating bending fatigue tests showed that, at room temperature, sludge particles play a detrimental role on fatigue behavior of T6 alloys, diminishing fatigue strength. At elevated temperatures (200 °C and after overaging, the influence of sludge is less relevant, probably due to a softening of the α-Al matrix and a reduction of stress concentration related to Fe-bearing intermetallics.

  12. Signature of intermittent behavior in the emission spectra of target associated particles from 84Kr-AgBr interactions at 0.95 GeV/A

    International Nuclear Information System (INIS)

    Bhattacharjee, B.

    2005-01-01

    Intermittency and fractal behavior have been studied for emission spectra of target associated fast and slow particles from 84 Kr-AgBr interactions at 0.95 GeV/A. Intermittent behavior is observed for both knocked out and slow target fragments. In both the cases anomalous dimensions are seen to increase with the order of moments thereby indicating the association of multifractility with production mechanism of both fast and slow target associated particles

  13. Influence of particle size on the low and high strain rate behavior of dense colloidal dispersions of nanosilica

    Energy Technology Data Exchange (ETDEWEB)

    Asija, Neelanchali; Chouhan, Hemant; Gebremeskel, Shishay Amare; Bhatnagar, Naresh, E-mail: nareshb@mech.iitd.ac.in [Indian Institute of Technology Delhi, Mechanical Engineering Department (India)

    2017-01-15

    Shear thickening is a non-Newtonian flow behavior characterized by the increase in apparent viscosity with the increase in applied shear rate, particularly when the shear rate exceeds a critical value termed as the critical shear rate (CSR). Due to this remarkable property of shear-thickening fluids (STFs), they are extensively used in hip protection pads, protective gear for athletes, and more recently in body armor. The use of STFs in body armor has led to the development of the concept of liquid body armor. In this study, the effect of particle size is explored on the low and high strain rate behavior of nanosilica dispersions, so as to predict the efficacy of STF-aided personal protection systems (PPS), specifically for ballistic applications. The low strain rate study was conducted on cone and plate rheometer, whereas the high strain rate characterization of STF was conducted on in-house fabricated split Hopkinson pressure bar (SHPB) system. Spherical nanosilica particles of three different sizes (100, 300, and 500 nm) as well as fumed silica particles of four different specific surface areas (Aerosil A-90, A-130, A-150, and A-200), respectively, were used in this study. The test samples were prepared by dispersing nanosilica particles in polypropylene glycol (PPG) using ultrasonic homogenization method. The low strain rate studies aided in determining the CSR of the synthesized STF dispersions, whereas the high strain rate studies explored the impact-resisting ability of STFs in terms of the impact toughness and the peak stress attained during the impact loading of STF in SHPB testing.

  14. Influence of particle size on the low and high strain rate behavior of dense colloidal dispersions of nanosilica

    Science.gov (United States)

    Asija, Neelanchali; Chouhan, Hemant; Gebremeskel, Shishay Amare; Bhatnagar, Naresh

    2017-01-01

    Shear thickening is a non-Newtonian flow behavior characterized by the increase in apparent viscosity with the increase in applied shear rate, particularly when the shear rate exceeds a critical value termed as the critical shear rate (CSR). Due to this remarkable property of shear-thickening fluids (STFs), they are extensively used in hip protection pads, protective gear for athletes, and more recently in body armor. The use of STFs in body armor has led to the development of the concept of liquid body armor. In this study, the effect of particle size is explored on the low and high strain rate behavior of nanosilica dispersions, so as to predict the efficacy of STF-aided personal protection systems (PPS), specifically for ballistic applications. The low strain rate study was conducted on cone and plate rheometer, whereas the high strain rate characterization of STF was conducted on in-house fabricated split Hopkinson pressure bar (SHPB) system. Spherical nanosilica particles of three different sizes (100, 300, and 500 nm) as well as fumed silica particles of four different specific surface areas (Aerosil A-90, A-130, A-150, and A-200), respectively, were used in this study. The test samples were prepared by dispersing nanosilica particles in polypropylene glycol (PPG) using ultrasonic homogenization method. The low strain rate studies aided in determining the CSR of the synthesized STF dispersions, whereas the high strain rate studies explored the impact-resisting ability of STFs in terms of the impact toughness and the peak stress attained during the impact loading of STF in SHPB testing.

  15. Advances in Understanding Energy Consumption Behavior and the Governance of Its Change – Outline of an Integrated Framework

    International Nuclear Information System (INIS)

    Burger, Paul; Bezençon, Valéry; Bornemann, Basil; Brosch, Tobias; Carabias-Hütter, Vicente; Farsi, Mehdi; Hille, Stefanie Lena; Moser, Corinne; Ramseier, Céline; Samuel, Robin; Sander, David; Schmidt, Stephan; Sohre, Annika; Volland, Benjamin

    2015-01-01

    Transforming today’s energy systems in industrialized countries requires a substantial reduction of the total energy consumption at the individual level. Selected instruments have been found to be effective in changing people’s behavior in single domains. However, the so far weak success story on reducing overall energy consumption indicates that our understanding of the determining factors of individual energy consumption as well as of its change is far from being conclusive. Among others, the scientific state of the art is dominated by analyzing single domains of consumption and by neglecting embodied energy. It also displays strong disciplinary splits and the literature often fails to distinguish between explaining behavior and explaining change of behavior. Moreover, there are knowledge gaps regarding the legitimacy and effectiveness of the governance of individual consumption behavior and its change. Against this backdrop, the aim of this paper is to establish an integrated interdisciplinary framework that offers a systematic basis for linking the different aspects in research on energy related consumption behavior, thus paving the way for establishing a better evidence base to inform societal actions. The framework connects the three relevant analytical aspects of the topic in question: (1) it systematically and conceptually frames the objects, i.e., the energy consumption behavior and its change (explananda); (2) it structures the factors that potentially explain the energy consumption behavior and its change (explanantia); (3) it provides a differentiated understanding of change inducing interventions in terms of governance. Based on the existing states of the art approaches from different disciplines within the social sciences, the proposed framework is supposed to guide interdisciplinary empirical research.

  16. Advances in Understanding Energy Consumption Behavior and the Governance of Its Change – Outline of an Integrated Framework

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Paul, E-mail: paul.burger@unibas.ch [Sustainability Research Group, University of Basel, Basel (Switzerland); Bezençon, Valéry [Enterprise Institute, University of Neuchâtel, Neuchâtel (Switzerland); Bornemann, Basil [Sustainability Research Group, University of Basel, Basel (Switzerland); Brosch, Tobias [Department of Psychology, Swiss Center for Affective Sciences, University of Geneva, Geneva (Switzerland); Carabias-Hütter, Vicente [Institute of Sustainable Development, Zurich University of Applied Sciences, Winterthur (Switzerland); Farsi, Mehdi [Institute of Economic Research, University of Neuchâtel, Neuchâtel (Switzerland); Hille, Stefanie Lena [Institute for Economy and the Environment, University of St. Gallen, St. Gallen (Switzerland); Moser, Corinne [Institute of Sustainable Development, Zurich University of Applied Sciences, Winterthur (Switzerland); Ramseier, Céline [Center for Energy Policy and Economics, ETH Zurich, Zurich (Switzerland); Samuel, Robin [Institute of Sociology, University of Bern, Bern (Switzerland); Social Research and Methodology Group, University of Basel, Basel (Switzerland); Sander, David [Department of Psychology, Swiss Center for Affective Sciences, University of Geneva, Geneva (Switzerland); Schmidt, Stephan; Sohre, Annika [Sustainability Research Group, University of Basel, Basel (Switzerland); Volland, Benjamin [Institute of Economic Research, University of Neuchâtel, Neuchâtel (Switzerland)

    2015-06-15

    Transforming today’s energy systems in industrialized countries requires a substantial reduction of the total energy consumption at the individual level. Selected instruments have been found to be effective in changing people’s behavior in single domains. However, the so far weak success story on reducing overall energy consumption indicates that our understanding of the determining factors of individual energy consumption as well as of its change is far from being conclusive. Among others, the scientific state of the art is dominated by analyzing single domains of consumption and by neglecting embodied energy. It also displays strong disciplinary splits and the literature often fails to distinguish between explaining behavior and explaining change of behavior. Moreover, there are knowledge gaps regarding the legitimacy and effectiveness of the governance of individual consumption behavior and its change. Against this backdrop, the aim of this paper is to establish an integrated interdisciplinary framework that offers a systematic basis for linking the different aspects in research on energy related consumption behavior, thus paving the way for establishing a better evidence base to inform societal actions. The framework connects the three relevant analytical aspects of the topic in question: (1) it systematically and conceptually frames the objects, i.e., the energy consumption behavior and its change (explananda); (2) it structures the factors that potentially explain the energy consumption behavior and its change (explanantia); (3) it provides a differentiated understanding of change inducing interventions in terms of governance. Based on the existing states of the art approaches from different disciplines within the social sciences, the proposed framework is supposed to guide interdisciplinary empirical research.

  17. Effects of fuel particle size and fission-fragment-enhanced irradiation creep on the in-pile behavior in CERCER composite pellets

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yunmei [Institute of Mechanics and Computational Engineering, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433 (China); Ding, Shurong, E-mail: dsr1971@163.com [Institute of Mechanics and Computational Engineering, Department of Aeronautics and Astronautics, Fudan University, Shanghai 200433 (China); Zhang, Xunchao; Wang, Canglong; Yang, Lei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-12-15

    The micro-scale finite element models for CERCER pellets with different-sized fuel particles are developed. With consideration of a grain-scale mechanistic irradiation swelling model in the fuel particles and the irradiation creep in the matrix, numerical simulations are performed to explore the effects of the particle size and the fission-fragment-enhanced irradiation creep on the thermo-mechanical behavior of CERCER pellets. The enhanced irradiation creep effect is applied in the 10 μm-thick fission fragment damage matrix layer surrounding the fuel particles. The obtained results indicate that (1) lower maximum temperature occurs in the cases with smaller-sized particles, and the effects of particle size on the mechanical behavior in pellets are intricate; (2) the first principal stress and radial axial stress remain compressive in the fission fragment damage layer at higher burnup, thus the mechanism of radial cracking found in the experiment can be better explained. - Highlights: • A grain-scale gas swelling model considering the development of recrystallization and resolution is adopted for particles. • The influence of fission-gas-induced porosity is considered in the constitutive relations for particles. • A simulation method is developed for the multi-scale thermo-mechanical behavior. • The effects of fuel particle size and fission-fragment-enhanced irradiation creep are investigated in pellets.

  18. Understanding determinants of government and consumer behavior relative to product safety : an application of the theory of planned behavior to China and the United States

    OpenAIRE

    Domke, Laura

    2008-01-01

    The following thesis applies Icek Ajzen's Theory of Planned Behavior to explain consumer and government response to safety of Chinese-made products sold in China and the United States. The thesis relies on secondary data as it considers the responses and actions relative to product safety by four different groups: Chinese government, U.S. government, Chinese consumers and U.S. consumers. Increased globalization has heightened the need for a better understanding and agreement...

  19. Animal models to improve our understanding and treatment of suicidal behavior.

    Science.gov (United States)

    Gould, T D; Georgiou, P; Brenner, L A; Brundin, L; Can, A; Courtet, P; Donaldson, Z R; Dwivedi, Y; Guillaume, S; Gottesman, I I; Kanekar, S; Lowry, C A; Renshaw, P F; Rujescu, D; Smith, E G; Turecki, G; Zanos, P; Zarate, C A; Zunszain, P A; Postolache, T T

    2017-04-11

    Worldwide, suicide is a leading cause of death. Although a sizable proportion of deaths by suicide may be preventable, it is well documented that despite major governmental and international investments in research, education and clinical practice suicide rates have not diminished and are even increasing among several at-risk populations. Although nonhuman animals do not engage in suicidal behavior amenable to translational studies, we argue that animal model systems are necessary to investigate candidate endophenotypes of suicidal behavior and the neurobiology underlying these endophenotypes. Animal models are similarly a critical resource to help delineate treatment targets and pharmacological means to improve our ability to manage the risk of suicide. In particular, certain pathophysiological pathways to suicidal behavior, including stress and hypothalamic-pituitary-adrenal axis dysfunction, neurotransmitter system abnormalities, endocrine and neuroimmune changes, aggression, impulsivity and decision-making deficits, as well as the role of critical interactions between genetic and epigenetic factors, development and environmental risk factors can be modeled in laboratory animals. We broadly describe human biological findings, as well as protective effects of medications such as lithium, clozapine, and ketamine associated with modifying risk of engaging in suicidal behavior that are readily translatable to animal models. Endophenotypes of suicidal behavior, studied in animal models, are further useful for moving observed associations with harmful environmental factors (for example, childhood adversity, mechanical trauma aeroallergens, pathogens, inflammation triggers) from association to causation, and developing preventative strategies. Further study in animals will contribute to a more informed, comprehensive, accelerated and ultimately impactful suicide research portfolio.

  20. Feeding on dispersed vs. aggregated particles: The effect of zooplankton feeding behavior on vertical flux

    DEFF Research Database (Denmark)

    Koski, Marja; Boutorh, Julia; De La Rocha, Christina L.

    2017-01-01

    Zooplankton feeding activity is hypothesized to attenuate the downward flux of elements in the ocean. We investigated whether the zooplankton community composition could influence the flux attenuation, due to the differences of feeding modes (feeding on dispersed vs. aggregated particles) and of ...

  1. Influence of Third Particle on the Tribological Behaviors of Diamond-like Carbon Films

    Science.gov (United States)

    Bai, Lichun; Srikanth, Narasimalu; Kang, Guozheng; Zhou, Kun

    2016-01-01

    Tribological mechanisms of diamond-like carbon (DLC) films in a sand-dust environment are commonly unclear due to the complicated three-body abrasion caused by sand particles. This study investigates the three-body abrasion of the DLC film via molecular dynamics simulations. The influence factors such as the load, velocity, shape of the particle and its size are considered. It has been found that the friction and wear of the DLC film are determined by adhesion at a small load but dominated by both adhesion and plowing at a large load. A high velocity can increase the friction of the DLC film but decrease its wear, due to the response of its networks to a high strain rate indicated by such velocity. The shape of the particle highly affects its movement mode and thus changes the friction and wear of the DLC film. It is found that a small-sized particle can increase the friction and wear of the DLC film by enhancing plowing. These unique tribological mechanisms of the DLC film can help to promote its wide applications in a sand-dust environment. PMID:27917916

  2. Collective magnetic behavior of biocompatible systems of maghemite particles coated with functional polymer shells

    Energy Technology Data Exchange (ETDEWEB)

    Demchenko, P.; Nedelko, N. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Mitina, N. [Lviv Polytechnic National University, 12 Bandera, Lviv 79013 (Ukraine); Lewińska, S.; Dłużewski, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Greneche, J.M. [Institut des Molécules et Matériaux du Mans, IMMM UMR CNRS 6283, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans (France); Ubizskii, S.; Navrotskyi, S.; Zaichenko, A. [Lviv Polytechnic National University, 12 Bandera, Lviv 79013 (Ukraine); Ślawska-Waniewska, A., E-mail: slaws@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland)

    2015-04-01

    Three series of core–shell maghemite nanoparticles were prepared by a template synthesis using surface active oligoperoxides and further surface initiated grafting functional polymers, forming shell suitable for biomedical applications. Because the polymer shells prevent exchange coupling between maghemite particles, the overall magnetic properties of the samples studied are dominated by dipolar interparticle interactions. Only the sample with the highest polymer fraction displays superparamagnetic relaxation phenomena close to the room temperature. On cooling, the magnetostatic interactions lead to a disordered collective magnetic state that should be described in terms of a spin-glass phenomenology. This collective freezing cannot however be considered as a generic spin-glass phase transition at a well-defined temperature but rather as freezing to a metastable glass-like state of locally correlated structural domains (clusters) without a long-range order. A quasi static spin ordering is only achieved at temperatures much below the freezing temperature. - Highlights: • Core–shell γ-Fe{sub 2}O{sub 3}/polymer particles were prepared using new surface active oligoperoxides. • Grafting of particle shells with functional polymers, suitable for biomedical applications. • Magnetic properties of nanocomposites are dominated by dipolar interactions. • On cooling magnetostatic interactions lead to a spin-glass-like state. • The most diluted maghemite particles display superparamagnetism at 300 K.

  3. Pre-asymptotic behavior of single-particle overlap integrals of non-Borromean two-neutron halos

    International Nuclear Information System (INIS)

    Timofeyuk, N.K.; Tostevin, J.A.; Blokhintsev, L.D.

    2003-01-01

    For non-Borromean two-neutron halo nuclei, modifications to the behavior of single-particle overlap integrals will arise due to the correlations of the two interacting nucleons in the halo. An additional contribution to the overlap integral can be obtained using the Feynman diagram approach. This additional term is modeled using a simple local potential model. We show that these modifications may play a role in detailed interpretations of experimental results from single-nucleon knockout, transfer, and other reactions that probe the single-nucleon overlap functions

  4. Effect of hydroxyapatite nano-particles on morphology, rheology and thermal behavior of poly(caprolactone)/chitosan blends

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Fereshte Mohammad [Department of Polymer Engineering, School of Chemical Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Kaffashi, Babak, E-mail: kaffashi@ut.ac.ir [Department of Polymer Engineering, School of Chemical Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Shokrollahi, Parvin, E-mail: p.shokrolahi@ippi.ac.ir [Department of Biomaterials, Iran Polymer and Petrochemical Institute, Tehran (Iran, Islamic Republic of); Akhlaghi, Shahin; Hedenqvist, Mikael S. [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Fibre and Polymer Technology, SE-100 44 Stockholm (Sweden)

    2016-02-01

    The effect of hydroxyapatite nano-particles (nHA) on morphology, and rheological and thermal properties of PCL/chitosan blends was investigated. The tendency of nHA to reside in the submicron-dispersed chitosan phase is determined using SEM and AFM images. The presence of electrostatic interaction between amide sites of chitosan and ionic groups on the nHA surface was proved by FTIR. It is shown that the chitosan phase is thermodynamically more favorable for the nano-particles to reside than the PCL phase. Lack of implementation of Cox–Merz theory for this system shows that the polymer–nano-particle network is destructed by the flow. Results from dynamic rheological measurements and Zener fractional model show that the presence of nHA increases the shear moduli and relaxation time of the PCL/chitosan blends. DSC measurements showed that nHA nano-particles are responsible for the increase in melting and crystallization characteristics of the PCL/chitosan blends. Based on thermogravimetric analysis, the PCL/chitosan/nHA nano-composites exhibited a greater thermal stability compared to the nHA-free blends. - Highlights: • In PCL/chitosan/nHA nano-composites, nHA shows tendency to chitosan phase. • At low shear rates, nano-composites show higher viscosity than unfilled blends. • At high shear rates, nano-composites show shear-thinning behavior. • nHA increases the shear moduli and relaxation time of PCL/chitosan blends. • The polymer/nano-particle network is destructed by the flow.

  5. Shared strategies for behavioral switching: understanding how locomotor patterns are turned on and off

    Directory of Open Access Journals (Sweden)

    Karen A Mesce

    2010-07-01

    Full Text Available Animals frequently switch from one behavior to another, often to meet the demands of their changing environment or internal state. What factors control these behavioral switches and the selection of what to do or what not to do? To address these issues, we will focus on the locomotor behaviors of two distantly related ‘worms’, the medicinal leech Hirudo verbana (clade Lophotrochozoa and the nematode Caenorhabditis elegans (clade Ecdysozoa. Although the neural architecture and body morphology of these organisms are quite distinct, they appear to switch between different forms of locomotion by using similar strategies of decision-making. For example, information that distinguishes between liquid and more solid environments dictates whether an animal swims or crawls. In the leech, dopamine biases locomotor neural networks so that crawling is turned on and swimming is turned off. In C. elegans, dopamine may also promote crawling, a form of locomotion that has gained new attention.

  6. Alcohol Use and Sexual Risk Behavior among College Students: Understanding Gender and Ethnic Differences

    Science.gov (United States)

    Randolph, Mary E.; Torres, Hector; Gore-Felton, Cheryl; Lloyd, Bronwyn; McGarvey, Elizabeth L.

    2015-01-01

    Objectives The purpose of the current study was to assess the role of gender and ethnicity in the relationship between alcohol use and risky sexual behavior. Method Sexually active college students (n = 425) reported on alcohol expectancies, perceived risk of HIV, and drinking and sexual behavior in the context of a larger health behavior survey. Results Approximately one-third of participants reported binge drinking 3 or more times in the past two weeks. African American women reported less drinking and less positive alcohol expectancies than other women. Older men engaged more often than younger men in binge drinking and reported more sexual partners in the past year. Younger age and greater perceived risk for HIV were positively associated with condom use for both women and men. Conclusion Collectively, these findings suggest that alcohol abuse and HIV prevention efforts among young adults need to consider gender, ethnicity, and age. PMID:19253158

  7. Understanding environment-influenced swarm behavior from a social force perspective

    Science.gov (United States)

    Jiang, J.; Lu, D.; Jiang, Y.; Lee, Z.; Zhang, Y.; Yu, J.

    2018-02-01

    The relevant research on swarm behavior has focused on the facts that when individuals agree with other members in the system globally consistent behaviors are generated and that individual decisions are completely dominated by other members. In fact, when individuals generate their own behavior strategies, they tend to consider not only the influences of other members but also autonomically consider their current environment. For example, in the social foraging of flocks, the behavior strategy of each individual animal is influenced by the food distribution, and individual movement patterns are characterized by a highly efficient search strategy-Lévy walks. To investigate this, this paper proposes using an environment-driven social force perspective to explore the Lévy walks of individuals in a group in patchy food environments. This model adopts the concept of social force to quantify the social effects and the interactions between individuals and food. The coordination between forces is a key in the formation of individual behavior strategies. Our simulation results show a power-law frequency distribution for agent flight lengths that conforms to Lévy walks and verifies the hypothesis of a relationship between food density and the Lévy index. In our model, the flock still exhibits collective consistency and cohesion and yields a high value for the order parameter and population density when moving between food patches. In addition, our model explains the intraspecific cooperation and competition that occurs during foraging as proposed in related work. The simulation also validates the impact of two inducements for individual behaviors compared with several benchmark models.

  8. Fundamental understanding of the synthesis and tribological behavior of organic-inorganic nanoparticles

    Science.gov (United States)

    Verma, Arpana

    The objective of this doctoral research is to design, synthesize, and test an advanced lubricant additive using novel active nanostructures of inorganic layered solid lubricant particles (MoS2), integrated and encapsulated with organic molecules, namely triglycerides and phospholipids, respectively. It was hypothesized that this combination can uniquely respond under severe boundary lubrication conditions (where high frictional losses exist). These organic-inorganic nanoparticles were synthesized using a top-down nanomanufacturing process, commonly known as high-energy ball milling or mechanical milling. It was performed in the presence of ambient air followed by organic molecules (triglycerides) to produce nanoparticles with controlled morphologies and surface properties. SEM, particle size analysis, and XRD showed a particle size reduction up to 100 nm and a grain size of 6 nm. TEM showed that after air milling for 48 hrs, agglomerated clusters of quasi-spherical nanoparticles of MoS2 were formed. HRTEM shows that the inter-planar defects and milling assisted shearing between the platelets caused the resultant curling of the planes, forming these unique nanostructures. Further milling of these clusters for 48 hrs in an organic medium (triglycerides) produced mono-dispersed quasi-spherical nanoparticles (lubrication, which is extremely important in a variety of applications including ball bearings, gears, transmissions etc., potentially saving hundreds of millions of dollars from fuel savings, reduced vehicle exhaust emissions and decreased down time, increasing the competitiveness of small and large US manufacturers. Even a modest 1.0% increase in efficiency will have a significant impact on the national economy . Innovations from this project should also benefit key application areas for organic-inorganic material complexes, for example pharmaceuticals, cosmetics and bio-fuels. Keywords/phrases. Advanced Lubricants, Solid Lubricant Nanoparticles, Top

  9. Studying Abroad: Understanding the Relationships among Beliefs, Perceived Value, and Behavioral Intentions

    Science.gov (United States)

    Zhuang, Weiling; King, Kristen; Carnes, Lana

    2015-01-01

    Increased globalization highlights the importance of encouraging university students to participate in an international experience. In this study, the authors investigate how behavioral belief, subjective belief, and control belief influence students' perceived value and intention to study abroad. The authors further examine the moderation effects…

  10. Evolutionary psychology: A fresh perspective for understanding and changing problematic behaviors

    NARCIS (Netherlands)

    Tybur, J.M.; Griskevicius, V.

    2013-01-01

    From rising obesity and soaring health care costs to escalating violence and environmental degradation, contemporary society faces many challenges. Are there policies that are naturally effective in changing the behaviors that produce these problems? In this article, the authors examine some of the

  11. Toward a Better Understanding of the Effects of Hindrance and Challenge Stressors on Work Behavior

    Science.gov (United States)

    Webster, Jennica R.; Beehr, Terry A.; Christiansen, Neil D.

    2010-01-01

    This study investigated the processes whereby hindrance and challenge stressors may affect work behavior. Three mechanisms were examined to explain the differential effects these stressors have demonstrated: job satisfaction, strains, and work self-efficacy. A model is proposed in which both types of stressors will result in increases in strains,…

  12. Evaluation of psychosocial measures for understanding weight-related behaviors in pregnant women.

    Science.gov (United States)

    Kendall, A; Olson, C M; Frongillo, E A

    2001-01-01

    The greatest weight gain for US. women occurs during the childbearing years of 25 to 34, and many obese women attribute their adult weight gain to childbearing. Few studies have examined psychosocial influences on women's behaviors during pregnancy, in part because of the lack of valid and reliable measures of psychosocial constructs relevant to pregnant women. Based on existing theory and an in-depth interview study, the psychosocial constructs of locus of control, self-efficacy, body image, feelings about motherhood, and career orientation were identified. Scales for each construct were constructed by drawing items from existing validated scales and writing items based on the in-depth interviews; their content validity assessed using factor analysis with oblique rotation and their reliability using Cronbach's alpha. Construct validity was assessed by examining the associations between scale scores and preexisting conditions of participants. Data for evaluating the scales came from a study of 622 pregnant women in a rural health care system who completed questionnaires and whose medical records were audited. Cronbach's alpha of the scales ranged from 0.73 to 0.89. Scale scores were strongly associated with lifestyle behaviors, body weight, and demographic characteristics of the participants. The analysis provides evidence of the validity of measures of psychosocial factors related to health behaviors of pregnant women. These measures should be useful in studying weight-related behaviors in pregnant women.

  13. Understanding Artful Behavior as a Human Proclivity: Clues from a Pre-Kindergarten Classroom

    Science.gov (United States)

    Blatt-Gross, Carolina

    2011-01-01

    Concurrent to the present reduction of arts education in mainstream American schools, many evolutionary-minded scholars are asserting that artistic behavior contributes significantly to cognition, has been advantageous for our survival, and satisfies psychological needs that are biologically embedded. Supported by long-term and wide-spread art…

  14. Understanding Student Behavioral Engagement: Importance of Student Interaction with Peers and Teachers

    Science.gov (United States)

    Nguyen, Tuan Dinh; Cannata, Marisa; Miller, Jason

    2018-01-01

    Recent theoretical conceptualizations of student engagement have raised questions about how to measure student engagement and how engagement varies not only across schools, but also within school and within classrooms. The authors build on existing research on student behavioral engagement and extend this research to emphasize a continuum of…

  15. Compliance pluralisme and processes : Understanding compliance behavior in restaurants in China

    NARCIS (Netherlands)

    Wu, Y.

    2017-01-01

    This research aimed to offer a case study of dynamic compliance processes in selected Chinese restaurants with the main methods of participant observation and in-depth interviews. It applied an integrated and dynamic research approach, called descriptive analysis of compliance behavior, which

  16. Understanding Teamwork Behaviors in the Use of New Ways of Working

    NARCIS (Netherlands)

    de Leede, Jan; Nijland, Joyce; de Leede, Jan

    2017-01-01

    New Ways of Working practices like activity-based working and home-based work lead to different behaviors of employees. Due to these NWW practices, employees choose their own preferred times and places to work – albeit to a certain extent and within certain boundaries. This might have an impact on

  17. But I'm Married: Understanding Relationship Status and College Students' Sexual Behaviors

    Science.gov (United States)

    Oswalt, Sara B.; Wyatt, Tammy J.

    2014-01-01

    Sexual health programs on college campuses are often directed toward single individuals with a focus on sexual risk. Using a sample of college students, this study examines how relationship status relates to sexual behaviors and may be a factor for sexual risk. Based on the study's results, expansion of sexual health programming on college…

  18. Understanding the influence of social interactions on individual's behavior pattern in a work environment

    NARCIS (Netherlands)

    Chen, Chih-Wei; Aztiria, Asier; Ben Allouch, Soumaya; Aghajan, Hamid; Salah, Albert Ali; Lepri, Bruno

    2011-01-01

    In this work, we study social interactions in a work environment and investigate how the presence of other people changes personal behavior patterns. We design the visual processing algorithms to track multiple people in the environment and detect dyadic interactions using a discriminative

  19. Understanding the relationship between teacher behavior and motivation in students with acquired deafblindness

    NARCIS (Netherlands)

    Haakma, Ineke; Janssen, Marleen; Minnaert, Alexander

    2016-01-01

    Because little is known about teacher-student relationships that involve students with acquired deafblindness, the authors performed a multiple case study with a multiple-method design to investigate the relationship between need-supportive teaching behaviors and student engagement. Using

  20. Understanding the privacy behavior of adolescents on Facebook : The role of peers, popularity and trust

    NARCIS (Netherlands)

    Hofstra, B.; Corten, R.; van Tubergen, F.A.

    2016-01-01

    We study whether peer influence processes, popularity and trust predict privacy settings on Facebook. We use large-scale survey data from 3434 Dutch adolescents combined with observed privacy behavior on Facebook. The findings show that peer influence processes play a role and that adolescents

  1. Understanding problematic game behavior : prevalence and the role of social cognitive determinants

    NARCIS (Netherlands)

    Haagsma, M.C.

    2012-01-01

    In the last two decades, there has been growing academic attention on the phenomenon of problematic game use. Empirical research has consistently identified a subgroup of gamers in Western, industrial countries who report adverse psychosocial consequences related to their video-gaming behavior. The

  2. Drunkorexia: Understanding the Co-Occurrence of Alcohol Consumption and Eating/Exercise Weight Management Behaviors

    Science.gov (United States)

    Barry, Adam E.; Piazza-Gardner, Anna K.

    2012-01-01

    Objective: Examine the co-occurrence of alcohol consumption, physical activity, and disordered eating behaviors via a drunkorexia perspective. Participants: Nationally representative sample (n = 22,488) of college students completing the Fall 2008 National College Health Assessment. Methods: Hierarchical logistic regression was employed to…

  3. Towards Understanding How to Assess Help-Seeking Behavior across Cultures

    Science.gov (United States)

    Ogan, Amy; Walker, Erin; Baker, Ryan; Rodrigo, Ma. Mercedes T.; Soriano, Jose Carlo; Castro, Maynor Jimenez

    2015-01-01

    In recent years, there has been increasing interest in automatically assessing help seeking, the process of referring to resources outside of oneself to accomplish a task or solve a problem. Research in the United States has shown that specific help-seeking behaviors led to better learning within intelligent tutoring systems. However, intelligent…

  4. Behavior of TPC`s in a high particle flux environment

    Energy Technology Data Exchange (ETDEWEB)

    Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Lindenbaum, S.J. [Brookhaven National Lab., Upton, NY (United States); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. [City College of New York, New York (United States); Hallman, T.J.; Madansky, L. [Johns Hopkins Univ., Baltimore, MD (United States); Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B. [Bonner Nuclear Lab., Houston, TX (United States)

    1991-12-31

    TPC`s (Time Projection Chamber) used in E-810 at the TAGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10 minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

  5. A pilot study of the behavior of gas- and particle-phase ETS tracers in residences

    International Nuclear Information System (INIS)

    Apte, Michael; Gundel, Lara; Dod, Raymond; Chang, Gee-Min; Sextro, Richard

    2002-01-01

    Our previous study of environmental tobacco smoke (ETS) in a three-room environmental chamber showed that smoking history significantly influenced inter-room ETS transport, particularly of gas-phase nicotine. We conducted a three-home pilot study where smoking was limited to one room. Single-smoker residences were monitored during five one-week periods while the smoker participated in a smoking cessation program. Nicotine traced ETS particles were detected reliably in the smoking rooms (SRs) and unreliably in the non-smoking rooms (NSRs). On average, the ventilation- and volume-normalized smoking rate, 0.1 Cigarette-h(sup -1) m(sup -3), added about 17 and 4(micro)g m(sup -3) of ETS particles into the SR and NSR, while average nicotine concentration increases were 2 and 0.06(micro)g m(sup -3), respectively. Thus, nicotine tracers may underestimate ETS particle exposure in a NSR (e.g., a child's bedroom) by a factor of 2 to 8. In other words, ETS exposure predicted from nicotine concentrations could be almost an order of magnitude lower than actual exposure

  6. Particle size distribution and behavior of sulfate aerosols in a coastal region

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, M.; Hashimoto, Y.

    1979-01-01

    To obtain fundamental knowledge about sulfate aerosols, a field research was conducted in a coastal region distant from industrial pollution sources. The aerosol samples were analyzed for some elements, sulfate and ammonium ions. Sulfate was determined by the turbidimetry with 2-aminoperimidine, and ammonium was by the colorimetry of indophenol method. Trace elements with short-lived nuclides were analyzed by instrumental neutron activation analysis. The mass-size distribution curve of total aerosols was the general bimodal pattern, although the concentration level was very low. Most of sulfate and ammonium salts were distributed in the fine particle range less than 2 microns in aerodynamic diameter, but sulfate had another peak, thought to be of maritime origin, in the coarse particle range. Nevertheless, many fine sulfate particles that had been produced secondarily in the atmosphere were found in such a less polluted coastal region. The change of the sulfate concentrations obtained by the two-stage Andersen type sampler showed a correlation with the humidity. This may suggest that the formation of sulfate aerosols from sulfur dioxide could be related to a catalytic oxidation process in water drops.

  7. Influence of moisture, particle size and pulse flour composition on phase transition behavior of rice flour.

    Science.gov (United States)

    Nithya, D J; Saravanan, M; Mohan, R Jagan; Alagusundaram, K

    2015-04-01

    Study on the phase transition characteristics is an important parameter in extrusion processing. The influence of Moisture Content (MC), particle size and level of cereal-pulse blend on the glass transition (Tg) and melt (Tm) temperatures of a ready to eat cereal-pulse formulation was determined. All samples were moisture conditioned in a 9 to 27 % with 3 % interval. Tg and Tm were measured by phase transition analyser (PTA). A substantial decrease in Tg and Tm was observed as moisture content level increased from 9 to 27 %. However Tg and Tm values could not be clearly defined below 9 % moisture content and above 27 % moisture content. The Tg and Tm values of the cereal-pulse formulation were found to be increased with increasing pulse composition (5 to 30 % with 5 % interval). Increase in particle size (150, 180, 212, 300, 425 and 500 μ) exhibited significant increase effect on Tg while less significant effect on Tm. This may be due to crystalline regions which play a role in cross linking amorphous regions of the polymeric network and thus suppress the mobility of amorphous regions. The observed differences in Tg and Tm induced by the moisture content, concentration of Bengal gram and particle size will be useful in simulation and optimization of barrel temperature set during extrusion processing.

  8. Behavior of Windblown Sand on Mars: Results from Single-Particle Experiments

    Science.gov (United States)

    Marshall, J. R.; Borucki, J.; Sagan, C.

    1999-01-01

    Experiments are investigating the behavior of individual sand grains in the high-energy martian aeolian regime. Energy partitioning during impact of a saltating grain determines grain longevity, but it also influences the way in which the bed becomes mobilized by reptation. When single grains of sand are fired into loose beds, the bed can absorb up to 90% of the impact energy by momentum transfer to other grains; it has been discovered that the impacting grains cause circular craters even at low impact angles. Hundreds of grains can be splashed by a single high-velocity (100 m/s) impact causing more bed disturbance through reptation than previously thought. The research is supported by NASA's PG&G Program. Because the martian aeolian environment in both high energy and of long duration, the most mobile fractions of windblown sand should have eradicated themselves by attrition, unless sand supply has kept pace with destruction. It is therefore important to understand the rate of grain attrition in order to make sense of the existence of vast dune fields on Mars. Attrition, has been addressed in other studies, but precise data for a single saltating grain striking a loose bed of sand have not been acquired -- the quintessential case to be understood for dunes on Mars. To acquire these data, we are employing a compound crossbow which has the bolt-firing mechanism replaced with a pneumatically-automated sabot system. The sabot can launch individual grains of sand of any size between several millimeters and about 50 microns, at velocities up to 100m/s. This is around the maximum velocity expected for saltating grains on Mars. The sabot sled is equipped with photoelectric sensors for measuring shot velocity. Baffling of the grain's exit orifice has enabled projection of single grains without significant aerodynamic effects from the sabot. Grains are fired into loose beds of sand at about 15 degrees from the horizontal (typical saltation trajectory at impact) while being

  9. High-Strain-Rate Material Behavior and Adiabatic Material Instability in Impact of Micron-Scale Al-6061 Particles

    Science.gov (United States)

    Chen, Qiyong; Alizadeh, Arash; Xie, Wanting; Wang, Xuemei; Champagne, Victor; Gouldstone, Andrew; Lee, Jae-Hwang; Müftü, Sinan

    2018-03-01

    Impact of spherical particles onto a flat sapphire surface was investigated in 50-950 m/s impact speed range experimentally and theoretically. Material parameters of the bilinear Johnson-Cook model were determined based on comparison of deformed particle shapes from experiment and simulation. Effects of high-strain-rate plastic flow, heat generation due to plasticity, material damage, interfacial friction and heat transfer were modeled. Four distinct regions were identified inside the particle by analyzing temporal variation of material flow. A relatively small volume of material near the impact zone becomes unstable due to plasticity-induced heating, accompanied by severe drop in the flow stress for impact velocity that exceeds 500 m/s. Outside of this region, flow stress is reduced due to temperature effects without the instability. Load carrying capacity of the material degrades and the material expands horizontally leading to jetting. The increase in overall plastic and frictional dissipation with impact velocity was found to be inherently lower than the increase in the kinetic energy at high speeds, leading to the instability. This work introduces a novel method to characterize HSR (109 s-1) material properties and also explains coupling between HSR material behavior and mechanics that lead to extreme deformation.

  10. Catalytic Behavior of Lipase Immobilized onto Congo Red and PEG-Decorated Particles

    Directory of Open Access Journals (Sweden)

    Rubens A. Silva

    2014-06-01

    Full Text Available Poly(ethylene glycol (PEG-decorated polystyrene (PS nanoparticles with mean hydrodynamic diameter (D and zeta–potential (ζ of (286 ± 15 nm and (−50 ± 5 mV, respectively, were modified by the adsorption of Congo red (CR. The PS/PEG/CR particles presented D and ζ values of (290 ± 19 nm and (−36 ± 5 mV, respectively. The adsorption of lipase onto PS/PEG or PS/PEG/CR particles at (24 ± 1 °C and pH 7 changed the mean D value to (380 ± 20 and (405 ± 11 nm, respectively, and ζ value to (−32 ± 4 mV and (−25 ± 2 mV, respectively. The kinetic parameters of the hydrolysis of p-nitrophenyl butyrate were determined for free lipase, lipase immobilized onto PS/PEG and PS/PEG/CR particles. Lipase on PS/PEG/CR presented the largest Michaelis-Menten constant (KM, but also the highest Vmax and kcat values. Moreover, it could be recycled seven times, losing a maximum 10% or 30% of the original enzymatic activity at 40 °C or 25 °C, respectively. Although lipases immobilized onto PS/PEG particles presented the smallest KM values, the reactions were comparatively the slowest and recycling was not possible. Hydrolysis reactions performed in the temperature range of 25 °C to 60 °C with free lipases and lipases immobilized onto PS/PEG/CR particles presented an optimal temperature at 40 °C. At 60 °C free lipases and lipases immobilized onto PS/PEG/CR presented ~80% and ~50% of the activity measured at 40 °C, indicating good thermal stability. Bioconjugation effects between CR and lipase were evidenced by circular dichroism spectroscopy and spectrophotometry. CR molecules mediate the open state conformation of the lipase lid and favor the substrate approaching.

  11. Understanding Fetal Alcohol Spectrum Disorders (FASDs: Toward Identification of a Behavioral Phenotype

    Directory of Open Access Journals (Sweden)

    Kelly Nash

    2008-01-01

    Full Text Available Fetal alcohol spectrum disorders (FASDs currently represent the leading cause of mental retardation in North America, ahead of Down syndrome and cerebral palsy. The damaging effects of alcohol on the developing brain have a cascading impact on the social and neurocognitive profiles of affected individuals. Researchers investigating the profiles of children with FASDs have found impairments in learning and memory, executive functioning, and language, as well as hyperactivity, impulsivity, poor communication skills, difficulties with social and moral reasoning, and psychopathology. The primary goal of this review paper is to examine current issues pertaining to the identification of a behavioral phenotype in FASDs, as well as to address related screening and diagnostic concerns. We conclude that future research initiatives comparing children with FASDs to nonalcohol-exposed children with similar cognitive and socioemotional profiles should aid in uncovering the unique behavioral phenotype for FASDs.

  12. Understanding the nanoscale local buckling behavior of vertically aligned MWCNT arrays with van der Waals interactions.

    Science.gov (United States)

    Li, Yupeng; Kim, Hyung-ick; Wei, Bingqing; Kang, Junmo; Choi, Jae-boong; Nam, Jae-Do; Suhr, Jonghwan

    2015-09-14

    The local buckling behavior of vertically aligned carbon nanotubes (VACNTs) has been investigated and interpreted in the view of a collective nanotube response by taking van der Waals interactions into account. To the best of our knowledge, this is the first report on the case of collective VACNT behavior regarding van der Waals force among nanotubes as a lateral support effect during the buckling process. The local buckling propagation and development of VACNTs were experimentally observed and theoretically analyzed by employing finite element modeling with lateral support from van der Waals interactions among nanotubes. Both experimental and theoretical analyses show that VACNTs buckled in the bottom region with many short waves and almost identical wavelengths, indicating a high mode buckling. Furthermore, the propagation and development mechanism of buckling waves follow the wave damping effect.

  13. Understanding Health and Health-Related Behavior of Users of Internet Health Information.

    Science.gov (United States)

    Wimble, Matt

    2016-10-01

    Little is known about how actual use of Internet health-related information is associated with health or health-related behavior. Using a nationally representative sample of 34,525 from 2012, this study examined the demographics of users of Internet health-related information (users), reports estimates of association with several health and behavioral outcomes adjusting for demographic factors, and analyzed the sample by education level, race, gender, and age. Analysis of a large nationally representative sample shows evidence that users of health-related information (users) on the Internet are younger, more educated, more likely to be insured, more likely to be female, and less likely to be African American. After adjusting for demographic differences, users are more likely to have been diagnosed with hypertension, cancer, stroke, and high cholesterol, but no evidence of current hypertension, weight-related issues, or being in fair or poor health. Users are less likely to smoke and among smokers are more likely to attempt quitting. Users are more likely to exercise, get a flu shot, pap smear, mammogram, HIV test, colon cancer screening, blood pressure check, and cholesterol check, but likely to be heavy drinkers. With few exceptions, results appear robust across gender, age groups, level of education, and ethnicity. Use is generally positively associated with prior diagnosis for several conditions and behaviors related to improved health, but I find no relationship with existing health status. The association between use of health-related Internet information and health-related behavior seems robust across levels of education, age, gender, and race.

  14. Living systems theory as a paradigm for organizational behavior: understanding humans, organizations, and social processes.

    Science.gov (United States)

    Vancouver, J B

    1996-07-01

    Living systems theories have been used to model human, organization, and communication processes. This paper attempts to describe these models and to highlight the isomorphisms among the models. Particular emphasis is given to self-regulating properties of humans as a subsystem of social systems. Attention is given to the advantages of generalizing across levels and phenomena and integrating the middle-range theories that dominate the field of organizational behavior. Three broad recommendations for future research are discussed.

  15. Social Psychology And Marketing: The Consumption Game. Understanding Marketing And Consumer Behavior Through Game Theory

    OpenAIRE

    Catalina BUTNARU

    2009-01-01

    Consumer psychology provides enough evidence that consumer behavior is not just one side of our existence, but, as a matter of fact, it is a central dimension of our everyday lives, engaging us into changing and defining our identity, beliefs, attitudes and practices. In relation to this, commodification has reached us on all levels: everything that people created, produced and developed over the years, during the post-industrial era, can be commodified and sold to a specific market. Commodif...

  16. Sociocultural Behavior Sensemaking: State of the Art in Understanding the Operational Environment

    Science.gov (United States)

    2014-01-01

    unreliable. Other work (Caimo & Friel, 2012) has wedded ERGMs to a Bayesian framework to assess the quality of model fit. This helps to avoid...population for behavior that contradicted Muslim values. The movement assumed other functions of government as well, such as performing wedding ... ceremonies . The FLN strategy was to win the respect and support of the people and thereby secure hideouts for themselves. Ethnic violence between the French

  17. Towards an integrative understanding of social behavior: new models and new opportunities

    Directory of Open Access Journals (Sweden)

    Daniel T Blumstein

    2010-06-01

    Full Text Available Social interactions among conspecifics are a fundamental and adaptively significant component of the biology of numerous species. Such interactions give rise to group living as well as many of the complex forms of cooperation and conflict that occur within animal groups. Although previous conceptual models have focused on the ecological causes and fitness consequences of variation in social interactions, recent developments in endocrinology, neuroscience, and molecular genetics offer exciting opportunities to develop more integrated research programs that will facilitate new insights into the physiological causes and consequences of social variation. Here, we propose an integrative framework of social behavior that emphasizes relationships between ultimate-level function and proximate-level mechanism, thereby providing a foundation for exploring the full diversity of factors that underlie variation in social interactions, and ultimately sociality. In addition to identifying new model systems for the study of human psychopathologies, this framework provides a mechanistic basis for predicting how social behavior will change in response to environmental variation. We argue that the study of non-model organisms is essential for implementing this integrative model of social behavior because such species can be studied simultaneously in the lab and field, thereby allowing integration of rigorously controlled experimental manipulations with detailed observations of the ecological contexts in which interactions among conspecifics occur.

  18. Toward an Integrative Understanding of Social Behavior: New Models and New Opportunities

    Science.gov (United States)

    Blumstein, Daniel T.; Ebensperger, Luis A.; Hayes, Loren D.; Vásquez, Rodrigo A.; Ahern, Todd H.; Burger, Joseph Robert; Dolezal, Adam G.; Dosmann, Andy; González-Mariscal, Gabriela; Harris, Breanna N.; Herrera, Emilio A.; Lacey, Eileen A.; Mateo, Jill; McGraw, Lisa A.; Olazábal, Daniel; Ramenofsky, Marilyn; Rubenstein, Dustin R.; Sakhai, Samuel A.; Saltzman, Wendy; Sainz-Borgo, Cristina; Soto-Gamboa, Mauricio; Stewart, Monica L.; Wey, Tina W.; Wingfield, John C.; Young, Larry J.

    2010-01-01

    Social interactions among conspecifics are a fundamental and adaptively significant component of the biology of numerous species. Such interactions give rise to group living as well as many of the complex forms of cooperation and conflict that occur within animal groups. Although previous conceptual models have focused on the ecological causes and fitness consequences of variation in social interactions, recent developments in endocrinology, neuroscience, and molecular genetics offer exciting opportunities to develop more integrated research programs that will facilitate new insights into the physiological causes and consequences of social variation. Here, we propose an integrative framework of social behavior that emphasizes relationships between ultimate-level function and proximate-level mechanism, thereby providing a foundation for exploring the full diversity of factors that underlie variation in social interactions, and ultimately sociality. In addition to identifying new model systems for the study of human psychopathologies, this framework provides a mechanistic basis for predicting how social behavior will change in response to environmental variation. We argue that the study of non-model organisms is essential for implementing this integrative model of social behavior because such species can be studied simultaneously in the lab and field, thereby allowing integration of rigorously controlled experimental manipulations with detailed observations of the ecological contexts in which interactions among conspecifics occur. PMID:20661457

  19. Using Social Network Analysis to Better Understand Compulsive Exercise Behavior Among a Sample of Sorority Members.

    Science.gov (United States)

    Patterson, Megan S; Goodson, Patricia

    2017-05-01

    Compulsive exercise, a form of unhealthy exercise often associated with prioritizing exercise and feeling guilty when exercise is missed, is a common precursor to and symptom of eating disorders. College-aged women are at high risk of exercising compulsively compared with other groups. Social network analysis (SNA) is a theoretical perspective and methodology allowing researchers to observe the effects of relational dynamics on the behaviors of people. SNA was used to assess the relationship between compulsive exercise and body dissatisfaction, physical activity, and network variables. Descriptive statistics were conducted using SPSS, and quadratic assignment procedure (QAP) analyses were conducted using UCINET. QAP regression analysis revealed a statistically significant model (R 2 = .375, P exercise behavior. Physical activity, body dissatisfaction, and network variables were statistically significant predictor variables in the QAP regression model. In our sample, women who are connected to "important" or "powerful" people in their network are likely to have higher compulsive exercise scores. This result provides healthcare practitioners key target points for intervention within similar groups of women. For scholars researching eating disorders and associated behaviors, this study supports looking into group dynamics and network structure in conjunction with body dissatisfaction and exercise frequency.

  20. The role of mobile phone technology in understanding and preventing suicidal behavior.

    NARCIS (Netherlands)

    Beurs, D. de; Kirtley, O.; Kerkhof, A.; Portzky, G.; O'Connor, R.C.

    2015-01-01

    In this editorial, we discuss how mobile phone technology has the potential to move the field forward in terms of understanding suicide risk as well as laying foundations for the development of effective treatments/interventions. We have focused on mobile health technology given the rapid growth of

  1. Understanding Manual-Based Behavior Therapy: Some Theoretical Foundations of Parent-Child Interaction Therapy.

    Science.gov (United States)

    Greco, Laurie A.; Sorrell, John T.; McNeil, Cheryl B.

    2001-01-01

    Provides a model of understanding and evaluating manualized treatments by beginning with a review of the theory and data-driven principles upon which one treatment, Parent-Child Interaction Therapy (PCIT), is based. As a point of illustration, several principles of PCIT, such as reinforcement, punishment, and stimulus control, are highlighted, and…

  2. Do Students Understand Our Course Structure? Implications for Important Classroom Attitudes and Behavior

    Science.gov (United States)

    Elicker, Joelle D.; Foust, Michelle Singer; Perry, Jennifer L.

    2015-01-01

    The complexity of a course's structure may influence how well students understand what is expected of them. Using the foundation of the industrial/organizational (I/O) psychology literature, the authors modified a measure of "Perceived System Knowledge" (Williams & Levy, 1992) for employee performance appraisal to be appropriate for…

  3. A Behavioral Approach to Understanding Green Consumerism Using Latent Class Choice Analysis

    DEFF Research Database (Denmark)

    Peschel, Anne Odile; Grebitus, Carola; Steiner, Bodo

    To better understand motivations of consumers making choices among sustainability-labeled food products, this paper analyzes drivers of stated choices for a dietary staple labeled with carbon and water foodprints. Latent class modeling of survey responses reveals distinct consumer segments based ...

  4. A Behavioral Approach to Understanding Green Consumerism Using Latent Class Choice Analysis

    DEFF Research Database (Denmark)

    Peschel, Anne Odile; Grebitus, Carola; Steiner, Bodo

    To better understand motivations of consumers making choices among sustainability-labeled food products, this paper analyzes drivers of stated choices for a dietary staple labeled with carbon and water foodprints. Latent class modeling of survey responses reveals distinct consumer segments based...

  5. Understanding travel information search behaviors by levels of information technology adoption

    Science.gov (United States)

    Junghye Angela Kah; Christine A. Vogt; Kelly MacKay

    2007-01-01

    Although the signifi cance of the Internet has been widely discussed in previous studies, the research of e-commerce has focused primarily on organizational and business perspectives (Sigala 2004). The growing number of Internet users allows a better understanding of online tourists who seek travel information and book or purchase travel products. The levels of...

  6. Validation of new empirical model for self-leveling behavior of cylindrical particle beds based on experimental database

    International Nuclear Information System (INIS)

    Morita, Koji; Matsumoto, Tatsuya; Taketa, Shohei; Nishi, Shinpei; Cheng, Songbai; Suzuki, Tohru; Tobita, Yoshiharu

    2014-01-01

    During a material relocation phase of core disruptive accidents (CDAs) in sodium cooled fast reactors (SFRs), debris beds can be formed in the lower plenum region due to rapid quenching and fragmentation of molten core materials. Heat removal from debris beds is crucial to achieve so called in-vessel retention (IVR) of degraded core materials. Coolant boiling in the beds may lead to leveling of their mound shape, and then changes coolability of the beds with decay heat as well as neutronic characteristics. To clarify the mechanisms underlying this self-leveling behavior, several series of experiments using simulant materials has been performed in collaboration between Japan Atomic Energy Agency (JAEA) and Kyushu University in Japan. In the present study, experiments in a cylindrical system were employed to develop experimental data on self-leveling process of particle beds. In the experiments, to simulate the coolant boiling due to the decay heat in fuel, nitrogen gas was percolated uniformly through the bottom of the particle bed with a conical shape mound using a gas injection method. Time variations in bed height during the self-leveling process were measured for key experimental parameters on particle size, density and sphericity, and gas flow rate. Using a dimensional analysis approach, a new model was proposed to correlate the experimental data on transient bed height with an empirical equation using a characteristic time of self-leveling development and a terminal equilibrium height of the bed. It was demonstrated that the proposed model predicts self-leveling development of particle beds with reasonable accuracy in the present ranges of experimental conditions. (author)

  7. Enhancing Asphalt Binder's Rheological Behavior and Aging Susceptibility Using Nano-Particles

    Science.gov (United States)

    Walters, Renaldo C.

    The life expectancy of Asphalt Binder (AB) has been negatively impacted by the harsh bombardment of UV rays. UV rays cause asphalt to oxidize faster which results in deterioration of asphalt rheological characteristics that can lead to pavement distresses. This study investigates the impact that nano-particles and bio modification have on the aging susceptibility of asphalt binder. As such, the following hypothesis was investigated: Introduction of nano particles to asphalt binder will reduce asphalt oxidation aging by increasing the inter layer spacing of the nano particles. Two nano scale materials were used for this study, nano-clay and bio-char as well as one micro scale material, silica fume. Nano-clay (Cloisite 30B) is a naturally occurring inorganic mineral. Bio-char is the waste product from bio-binder production. Bio-binder is produced from swine manure using a thermochemical conversion process. This process is then followed by a filtration procedure where the bio-char is produced. Chemical and physical properties of bio-char showed a significant presence of carbon which could in turn reduce the rate of asphalt oxidation. Silica Fume is an ultra-fine powder collected as a by-product of silicon and ferrosilicon alloy production and consists of spherical particles. In this study several mixtures are designed and evaluated using RV testing (Rotational Viscometer), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Nano-clay is blended at 2% and 4% by weight of dry mass, with and without bio-binder (5% by weight of dry mass). Bio-char is grinded to nano scale and added to the virgin asphalt binder (PG 64-22) at 2%, 5% and 10% by weight of dry mass. Silica Fume is added to virgin asphalt binder (PG 64-22) at 2%, 4% and 8% by weight of dry mass. The optimum percent of nano scale material that is added to virgin asphalt binder is expected to reduce aging susceptibility of asphalt binder, extending its service life.

  8. Classical particle-like behavior of Sine--Gordon solitons in scattering potentials and applied fields

    International Nuclear Information System (INIS)

    Fogel, M.B.; Trullinger, S.E.; Bishop, A.R.; Krumhansl, J.A.

    1976-02-01

    We show that classical Sine-Gordon solitons maintain their integrity to a high degree in the presence of external perturbations. Two examples, of particular importance in condensed matter, are described in detail: (i) a model impurity is found to bind low-velocity solitons but merely phase-shift those with high-velocities, (ii) external static driving terms with damping accelerate the soliton to a terminal velocity. The importance of a translation mode is emphasized and it is concluded that the soliton behaves as a classical particle in all essential respects

  9. Effects of roughage inclusion and particle size on performance and rumination behavior of finishing beef steers

    Science.gov (United States)

    Roughage is mechanically processed to increase digestibility, and handling and mixing characteristics in finishing diets. Roughage is fed to promote rumen health and decrease digestive upset, but inclusion in finishing diets is limited due to the cost per unit of energy. Rumination behavior may be a...

  10. Symbolic Interactionism: A Framework for Understanding Risk-Taking Behaviors in Farm Communities.

    Science.gov (United States)

    Sorensen, Julie A; Tinc, Pamela J; Weil, Rebecca; Droullard, David

    2017-01-01

    Risk behaviors are key drivers of occupationally related injuries and illnesses, considerably impacting the uptake and success of injury interventions, technologies, and practices. This is certainly true in the agricultural sector, where farmers often ignore recommended safety practices or have even been known to disable safety technologies. Although research studies have characterized specific individual safety or risk behaviors, few studies have thoroughly examined farmers' risk and safety orientations or how these develop in response to environmental and societal exposures. This study utilizes data collected over the past decade with a variety of small to midsize farm personnel to explore the meanings that farmers ascribe to risk and safety and how these influence risk and safety behaviors. In all, over 90 interviews with farmers, farm-wives, and family members were reviewed. Researchers used a grounded theory approach to identify patterns of environmental and societal exposures, as well as their impact on farmers' risk and safety orientations. Analysis revealed exposures and orientations to risk and safety, which could be largely explained through the lens of symbolic interactionism. This framework posits that people create a sense-of-self as a way of adjusting and adapting to their environment. For farmers in this study, belief in their ability to persevere allows them to succeed, despite the considerable stressors and challenges they face each day. However, this identity can, at times, be maladaptive when it is applied to safety decisions and hazard exposures. The authors discuss the implications of this research and how it may be used to productively inform future farm safety efforts.

  11. Context for understanding psychosocial outcomes and behavior among adolescents and young adults with cancer.

    Science.gov (United States)

    Zebrack, Brad; Butler, Melissa

    2012-09-01

    Across all age groups, cancer affects relationships with family and friends; challenges one's sense of independence; disrupts goals, aspirations, and achievements; alters one's body image and integrity; and poses existential challenges about the world and one's place in it. When diagnosed with cancer, adolescents and young adults (AYAs) in their 20s and 30s face unique challenges compared with younger children and older adults. Understanding how cancer-related challenges manifest needs and desires for psychological and social support services throughout a continuum of care may help clinicians improve cost-effective quality care and patient outcomes. This article provides a context for understanding the experiences of AYAs with cancer and highlights key domains of psychosocial need in this population.

  12. Understanding the dynamics of sustainable social-ecological systems: human behavior, institutions, and regulatory feedback networks.

    Science.gov (United States)

    Anderies, John M

    2015-02-01

    I present a general mathematical modeling framework that can provide a foundation for the study of sustainability in social- ecological systems (SESs). Using basic principles from feedback control and a sequence of specific models from bioeconomics and economic growth, I outline several mathematical and empirical challenges associated with the study of sustainability of SESs. These challenges are categorized into three classes: (1) the social choice of performance measures, (2) uncertainty, and (3) collective action. Finally, I present some opportunities for combining stylized dynamical systems models with empirical data on human behavior and biophysical systems to address practical challenges for the design of effective governance regimes (policy feedbacks) for highly uncertain natural resource systems.

  13. Evolutionary psychology and evolutionary developmental psychology: understanding the evolution of human behavior and development.

    Science.gov (United States)

    Hernández Blasi, Carlos; Causey, Kayla

    2010-02-01

    This is an introduction to this special issue on evolutionary psychology (EP) and evolutionary developmental psychology (EDP). We suggest here that, contrary to some common assumptions, mainstream psychology continues to be essentially non Darwinian and that EP and EDP are new approaches that can potentially help us to change this situation. We then present the organization of the special issue (composed of six papers). We conclude that evolution is certainly not the final consideration in psychology, but emphasize its importance as the basis upon which all modern behaviors and development are built.

  14. Towards a better understanding and behavior recognition of inhabitants in smart cities. A public transport case

    OpenAIRE

    Klimek, Radoslaw; Kotulski, Leszek

    2015-01-01

    The idea of modern urban systems and smart cities requires monitoring and careful analysis of different signals. Such signals can originate from different sources and one of the most promising is the BTS, i.e. base transceiver station, an element of mobile carrier networks. This paper presents the fundamental problems of elicitation, classification and understanding of such signals so as to develop context-aware and pro-active systems in urban areas. These systems are characterized by the omn...

  15. The classical Pierce diode: Using particle simulations on linear and nonlinear behavior and final states

    International Nuclear Information System (INIS)

    Crystal, T.L.; Kuhn, S.; Birdsall, C.K.

    1984-01-01

    The classical Pierce diode is a simple 1-d system of two shorted metal plates, a cold beam of electrons injected from one side and a neutralizing background of rigid ions. While the plasma medium is technically stable, the finiteness of the Pierce system allows stable and unstable operation. It is usefully studied as an archetypical bounded plasma system, related e.g., to Q-machines, particle accelerators, thermionic converters. New particle simulations of the Pierce diode have successfully recovered many novel linear phenomena including the dominant linear eigenmodes (seen in the internal electrostatic fields), and the dominant and subdominant eigenfrequencies, (seen both in the internal electrostatics and in the external circuit current, J/sub ext/(t)). These simulation results conform very well to detailed predictions of a new linear analysis. The final (nonlinear) state recovered can show critical dependence on initial (linear perturbation) conditions, and can be made steady-state (d.c.) or periodic-oscillatory by simply changing the initial conditions by a factor of 10/sup -4/ or less. A third class of final state is also possible which has oscillations which seem to be nonperiodic

  16. The Effect of Soil Particle Arrangement on Shear Strength Behavior of Silty Sand

    Directory of Open Access Journals (Sweden)

    Nik Norsyahariati Nik Daud

    2016-01-01

    Full Text Available The presence of fines in sandy soil is recognized as a problem in geotechnical engineering. It is often assumed that the strength and liquefaction potential of a soil decreases with increasing fines content. Sand with a significant amount of fines is always encountered in geotechnical engineering projects. The main interest of this paper is to study the effect of particles arrangement and stress behaviour on sand and silty sand sample. The objectives are to determine the basic properties as well as the morphological and mineralogical properties and the relationship of those properties to the stress behaviour of the soils. Sand-silt mixtures with fines contents of 20% and 40% were prepared and a series of testing was carried out to determine their basic properties, morphological and thin section properties, and mechanical properties by using direct shear box equipment. Results show that the basic properties and morphological properties of soil affect the mechanical behaviour of soil. Shape of the soil particle can influence the packing of the soil, hence altering the mechanical behaviour of the soil. From the thin section, the soil is observed to be well graded and have a dense packing while the minerals observed were mainly quartz and rutile.

  17. Understanding the Mechanisms behind Changing People’s Recycling Behavior at Work by Applying a Comprehensive Action Determination Model

    Directory of Open Access Journals (Sweden)

    Sunita Prugsamatz Ofstad

    2017-02-01

    Full Text Available This study moves toward a better understanding of the mechanisms behind changing people’s recycling behavior at work by mapping out which pathways and variables change in recycling behavior as triggered by interventions. A questionnaire was designed based on the theory of planned behaviour, the norm-activation model, habits, and a comprehensive action determination model (CADM. The data was collected in two rounds: before the intervention and after a three-month pilot period with implemented interventions using a sample of n = 1269 students and employees. The CADM model appears to be a good fit with the data. The results from the structural equation modelling indicate the pathways to influencing behavioural change. The most important psychological variables accounting for waste separation behaviour are intentions, perceived behavioural control, personal norms, social norms and habits. No difference in waste separation behaviour was observed in the control building. Interventions targeting the increase in waste separation raised participants’ intentions to engage in such behaviour. Results indicate that waste separation at work must go beyond technical aspects to include various key elements of sustainability to ensure success. Furthermore, understanding human behavior is key in determining the performance and success of an integrated and effective recycling intervention strategy.

  18. Understanding pregnancy-related attitudes and behaviors: a mixed-methods study of homeless youth.

    Science.gov (United States)

    Tucker, Joan S; Sussell, Jesse; Golinelli, Daniela; Zhou, Annie; Kennedy, David P; Wenzel, Suzanne L

    2012-12-01

    Pregnancy rates are substantially higher among homeless youth than in the general population of youth, yet little is known about homeless adolescents' and young adults' pregnancy-related attitudes and behaviors. Pregnancy-related attitudes and behaviors were examined among two samples of sexually active homeless 13-24-year-olds in Los Angeles County. Data from 37 semistructured interviews conducted in March-April 2011 were analyzed using standard qualitative methods. Data from a structured survey with 277 respondents, conducted between October 2008 and August 2009, were analyzed primarily using regression modeling. More than half of interview respondents held ambivalent attitudes toward pregnancy, and ambivalent youth reported less contraceptive use than others. The interviews identified several potential influences on pregnancy attitudes: barriers associated with homelessness, readiness to settle down, desire to achieve goals, belief that a child would create something positive in life, and family and partners. In the survey, having positive attitudes toward pregnancy was positively associated with duration of homelessness (odds ratio, 1.6), contact with relatives (1.1) and relationship commitment (1.8); it was negatively associated with frequency of drinking (0.9). Relationship commitment was positively associated with nonuse of an effective contraceptive method at last sex (1.5). Effective and accessible pregnancy prevention and family planning programs for homeless youth are needed. Youths' ambivalence toward pregnancy and feelings of relationship commitment warrant attention as possible areas for programs to address. Copyright © 2012 by the Guttmacher Institute.

  19. The Gist of Delay of Gratification: Understanding and Predicting Problem Behaviors.

    Science.gov (United States)

    Reyna, Valerie F; Wilhelms, Evan A

    2017-04-01

    Delay of gratification captures elements of temptation and self-denial that characterize real-life problems with money and other problem behaviors such as unhealthy risk taking. According to fuzzy-trace theory, decision makers mentally represent social values such as delay of gratification in a coarse but meaningful form of memory called "gist." Applying this theory, we developed a gist measure of delay of gratification that does not involve quantitative trade-offs (as delay discounting does) and hypothesize that this construct explains unique variance beyond sensation seeking and inhibition in accounting for problem behaviors. Across four studies, we examine this Delay-of-gratification Gist Scale by using principal components analyses and evaluating convergent and divergent validity with other potentially related scales such as Future Orientation, Propensity to Plan, Time Perspectives Inventory, Spendthrift-Tightwad, Sensation Seeking, Cognitive Reflection, Barratt Impulsiveness, and the Monetary Choice Questionnaire (delay discounting). The new 12-item measure captured a single dimension of delay of gratification, correlated as predicted with other scales, but accounted for unique variance in predicting such outcomes as overdrawing bank accounts, substance abuse, and overall subjective well-being. Results support a theoretical distinction between reward-related approach motivation, including sensation seeking, and inhibitory faculties, including cognitive reflection. However, individuals' agreement with the qualitative gist of delay of gratification, as expressed in many cultural traditions, could not be reduced to such dualist distinctions nor to quantitative conceptions of delay discounting, shedding light on mechanisms of self-control and risk taking.

  20. Understanding the impact of the central atom on the ionic liquid behavior: Phosphonium vs ammonium cations

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Pedro J.; Ventura, Sónia P. M.; Batista, Marta L. S.; Schröder, Bernd; Coutinho, João A. P., E-mail: jcoutinho@ua.pt [CICECO, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Gonçalves, Fernando [Departamento de Biologia e CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, 3810-193 Aveiro (Portugal); Esperança, José [Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-901 Oeiras (Portugal); Mutelet, Fabrice [Laboratoire Réactions et Génie des Procédés, CNRS (UPR3349), Nancy-Université, 1 rue Grandville, BP 20451 54001 Nancy (France)

    2014-02-14

    The influence of the cation's central atom in the behavior of pairs of ammonium- and phosphonium-based ionic liquids was investigated through the measurement of densities, viscosities, melting temperatures, activity coefficients at infinite dilution, refractive indices, and toxicity against Vibrio fischeri. All the properties investigated are affected by the cation's central atom nature, with ammonium-based ionic liquids presenting higher densities, viscosities, melting temperatures, and enthalpies. Activity coefficients at infinite dilution show the ammonium-based ionic liquids to present slightly higher infinite dilution activity coefficients for non-polar solvents, becoming slightly lower for polar solvents, suggesting that the ammonium-based ionic liquids present somewhat higher polarities. In good agreement these compounds present lower toxicities than the phosphonium congeners. To explain this behavior quantum chemical gas phase DFT calculations were performed on isolated ion pairs at the BP-TZVP level of theory. Electronic density results were used to derive electrostatic potentials of the identified minimum conformers. Electrostatic potential-derived CHelpG and Natural Population Analysis charges show the P atom of the tetraalkylphosphonium-based ionic liquids cation to be more positively charged than the N atom in the tetraalkylammonium-based analogous IL cation, and a noticeable charge delocalization occurring in the tetraalkylammonium cation, when compared with the respective phosphonium congener. It is argued that this charge delocalization is responsible for the enhanced polarity observed on the ammonium based ionic liquids explaining the changes in the thermophysical properties observed.

  1. Understanding smallholders’ intended deforestation behavior in the Brazilian Cerrado following environmental registry

    Science.gov (United States)

    Vang Rasmussen, Laura; Jung, Suhyun; Dantas Brites, Alice; Watkins, Cristy; Agrawal, Arun

    2016-09-01

    Brazil’s Rural Environmental Registry (CAR) is a potentially promising avenue to slow deforestation on private properties as it facilitates the monitoring of land use. Yet limited empirical evidence exists on how the CAR affects smallholders’ behavior and recent scholarly efforts have in fact indicated that it may be doing less to protect forests than previously assumed. Based on 1177 smallholder surveys conducted in the Cerrado, we assess 1) whether the CAR might incentivize smallholders to pursue deforestation and 2) which factors are associated with smallholders’ intended deforestation behavior. We find that upon CAR registration, factors significantly associated with smallholders’ intention to deforest are: the existing percentage of native vegetation on the property, the use of agricultural loans, property owner’s age, and livestock production experience. To curb deforestation that may follow expressed intentions of smallholders, the CAR, and environmental registration programs alike, should account for existing land use by, for example, improving the system already in place for trading areas of native vegetation as this system is not widely adopted by those smallholders with more native vegetation than the legal cut-off. Also, such programs should assess the role of whether conditions related to land cover maintenance may protect against deforestation if credit access is supported especially to younger smallholders and/or livestock producers with a high percentage of native vegetation in their properties.

  2. Fractured Identity: A Framework for Understanding Young Asian American Women's Self-harm and Suicidal Behaviors.

    Science.gov (United States)

    Hahm, Hyeouk Chris; Gonyea, Judith G; Chiao, Christine; Koritsanszky, Luca Anna

    2014-01-01

    Despite the high suicide rate among young Asian American women, the reasons for this phenomenon remain unclear. This qualitative study explored the family experiences of 16 young Asian American women who are children of immigrants and report a history of self-harm and/or suicidal behaviors. Our findings suggest that the participants experienced multiple types of "disempowering parenting styles" that are characterized as: abusive, burdening, culturally disjointed, disengaged, and gender-prescriptive parenting. Tied to these family dynamics is the double bind that participants suffer. Exposed to multiple types of negative parenting, the women felt paralyzed by opposing forces, caught between a deep desire to satisfy their parents' expectations as well as societal expectations and to simultaneously rebel against the image of "the perfect Asian woman." Torn by the double bind, these women developed a "fractured identity," which led to the use of "unsafe coping" strategies. Trapped in a "web of pain," the young women suffered alone and engaged in self-harm and suicidal behaviors.

  3. Understanding Spatiotemporal Patterns of Biking Behavior by Analyzing Massive Bike Sharing Data in Chicago.

    Science.gov (United States)

    Zhou, Xiaolu

    2015-01-01

    The growing number of bike sharing systems (BSS) in many cities largely facilitates biking for transportation and recreation. Most recent bike sharing systems produce time and location specific data, which enables the study of travel behavior and mobility of each individual. However, despite a rapid growth of interest, studies on massive bike sharing data and the underneath travel pattern are still limited. Few studies have explored and visualized spatiotemporal patterns of bike sharing behavior using flow clustering, nor examined the station functional profiles based on over-demand patterns. This study investigated the spatiotemporal biking pattern in Chicago by analyzing massive BSS data from July to December in 2013 and 2014. The BSS in Chicago gained more popularity. About 15.9% more people subscribed to this service. Specifically, we constructed bike flow similarity graph and used fastgreedy algorithm to detect spatial communities of biking flows. By using the proposed methods, we discovered unique travel patterns on weekdays and weekends as well as different travel trends for customers and subscribers from the noisy massive amount data. In addition, we also examined the temporal demands for bikes and docks using hierarchical clustering method. Results demonstrated the modeled over-demand patterns in Chicago. This study contributes to offer better knowledge of biking flow patterns, which was difficult to obtain using traditional methods. Given the trend of increasing popularity of the BSS and data openness in different cities, methods used in this study can extend to examine the biking patterns and BSS functionality in different cities.

  4. Understanding Youth Antisocial Behavior Using Neuroscience through a Developmental Psychopathology Lens: Review, Integration, and Directions for Research

    Science.gov (United States)

    Hyde, Luke W.; Shaw, Daniel S.; Hariri, Ahmad R.

    2013-01-01

    Youth antisocial behavior (AB) is an important public health concern impacting perpetrators, victims, and society. Functional neuroimaging is becoming a more common and useful modality for understanding neural correlates of youth AB. Although there has been a recent increase in neuroimaging studies of youth AB and corresponding theoretical articles on the neurobiology of AB, there has been little work critically examining the strengths and weaknesses of individual studies and using this knowledge to inform the design of future studies. Additionally, research on neuroimaging and youth AB has not been integrated within the broader framework of developmental psychopathology. Thus, this paper provides an in-depth review of the youth AB functional neuroimaging literature with the following goals: 1. to evaluate how this literature has informed our understanding of youth AB, 2. to evaluate current neuroimaging studies of youth AB from a developmental psychopathology perspective with a focus on integrating research from neuroscience and developmental psychopathology, as well as placing this research in the context of other related areas (e.g., psychopathy, molecular genetics), and 3. to examine strengths and weaknesses of neuroimaging and behavioral studies of youth AB to suggest how future studies can develop a more informed and integrated understanding of youth AB. PMID:24273368

  5. Modulation of mesenchymal stem cell behavior by nano- and micro-sized β-tricalcium phosphate particles in suspension and composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Smoak, Mollie; Hogan, Katie; Kriegh, Lisa; Chen, Cong, E-mail: cchen19@tigers.lsu.edu; Terrell, LeKeith B.; Qureshi, Ammar T.; Todd Monroe, W. [Louisiana State University and LSU AgCenter, Department of Biological and Agricultural Engineering (United States); Gimble, Jeffrey M., E-mail: Jeffrey.Gimble@pbrc.edu [Tulane University School of Medicine, Center for Stem Cell Research & Regenerative Medicine (United States); Hayes, Daniel J., E-mail: danielhayes@lsu.edu [Louisiana State University and LSU AgCenter, Department of Biological and Agricultural Engineering (United States)

    2015-04-15

    Interest has grown in the use of microparticles and nanoparticles for modifying the mechanical and biological properties of synthetic bone composite structures. Micro- and nano-sized calcium phosphates are of interest for their osteoinductive behavior. Engineered composites incorporating polymers and ceramics, such as poly-l-lactic acid (PLLA) and beta-tricalcium phosphate (β-TCP), for bone tissue regeneration have been well investigated for their proliferative and osteoinductive abilities. Only limited research has been done to investigate the effects of different sizes of β-TCP particles on human mesenchymal stromal cell behavior. As such, the aim of this study was to investigate the modulations of human adipose-derived stem cell (hASCs) behavior within cell/particle and cell/composite systems as functions of particle size, concentration, and exposure time. The incorporation of nanoscale calcium phosphate resulted in improved mechanical properties and osteogenic behavior within the scaffold compared to the microscale calcium phosphate additives. Particle exposure results indicate that cytotoxicity on hASCs correlates inversely with particle size and increases with the increasing exposure time and particle concentration. Composites with increasing β-TCP content, whether microparticles or nanoparticles, were less toxic than colloidal micro- and nano-sized β-TCP particles directly supplied to hASCs. The difference in viability observed as a result of varying exposure route is likely related to the increased cell–particle interactions in the direct exposure compared to the particles becoming trapped within the scaffold/polymer matrix.

  6. Understanding the adsorption interface of polyelectrolyte coating on redox active nanoparticles using soft particle electrokinetics and its biological activity.

    Science.gov (United States)

    Saraf, Shashank; Neal, Craig J; Das, Soumen; Barkam, Swetha; McCormack, Rameech; Seal, Sudipta

    2014-04-23

    The application of cerium oxide nanoparticles (CNPs) for therapeutic purposes requires a stable dispersion of nanoparticles in a biological environment. The objective of this study is to tailor the properties of polyelectrolyte coated CNPs as a function of molecular weight to achieve a stable and catalytic active dispersion. The coating of CNPs with polyacrylic acid (PAA) has increased the dispersion stability of CNPs and enhanced the catalytic ability. The stability of PAA coating was analyzed using the change in the Gibbs free energy computed by the Langmuir adsorption model. The adsorption isotherms were determined using soft particle electrokinetics which overcomes the challenges presented by other techniques. The change in Gibbs free energy was highest for CNPs coated with PAA of 250 kg/mol indicating the most stable coating. The change in free energy for PAA of 100 kg/mol coated CNPs was 85% lower than the PAA of 250 kg/mol coated CNPs. This significant difference is caused by the strong adsorption of PAA of 100 kg/mol on CNPs. Catalytic activity of PAA-CNPs is assessed by the catalase enzymatic mimetic activity of nanoparticles. The catalase activity was higher for PAA coated CNPs as compared to bare CNPs which indicated preferential adsorption of hydrogen peroxide induced by coating. This indicates that the catalase activity is also affected by the structure of the coating layer.

  7. Understanding Psychosocial and High-Risk Sexual Behaviors Among Detained Juveniles: A Descriptive Study Protocol.

    Science.gov (United States)

    Gates, Madison L; Staples-Horne, Michelle; Cartier, Jeanne; Best, Candace; Walker, Veronica; Schwartz, David; Yoo, Wonsuk

    2015-12-30

    African American women are disproportionately impacted by sexually transmitted infections (STIs), such as chlamydia and gonorrhea, which are known risk factors for human immunodeficiency virus (HIV) infection. STIs, particularly chlamydia and gonorrhea, are even more prevalent among young African American women with a juvenile detention history. The population with experiences with the criminal justice system has greater rates of STIs and is diagnosed more often with mental health issues, often related to sexual abuse or intimate partner violence, compared to peers who have not been detained by law enforcement. Psychosocial factors, especially those related to intimate relationships (ie, the imperativeness of being in a relationship and the power one has in their relationship), have emerged as important explanatory factors for acquiring STIs, including HIV, and a component of risk reduction interventions. To investigate more comprehensively the relationship between psychosocial risk factors and STIs, including HIV, as it relates to reduction and prevention of these diseases. The long-term goal is to improve the effectiveness of evidence-based interventions with a major focus on intimate relationship dynamics. This descriptive study surveys young women (ages 13-17) who have been detained (incarcerated) by a department of juvenile justice. In addition to being female and detained, eligibility criteria include being detained longer than 30 days and being free of cognitive impairments. This study will include young women from one juvenile detention center. The primary outcomes to be measured are STI knowledge, intimate relationship dynamics (ie, imperativeness and power), and high-risk sexual behaviors. High-risk sexual behaviors will be assessed using data extracted from health records. Preliminarily, we have received assent from 26 primarily young African American women. The majority of participants (81%) had inadequate knowledge about STIs, 52% perceived a lack of

  8. Understanding the viscoelastic behavior of arterial elastin in glucose via relaxation time distribution spectrum.

    Science.gov (United States)

    Wang, Yunjie; Li, Haiyue; Zhang, Yanhang

    2018-01-01

    Elastin is a critical extracellular matrix protein that provides many biological tissues with resilience. In elastic arteries such as aorta, elasticity is crucial for energy storage and transmission of the pulsatile blood flow. As one of the main mechanisms of aging, non-enzymatic glycation can greatly compromise the mechanical properties of the long-lived elastin. In this study, effect of glucose on the viscoelastic behavior of purified porcine aortic elastin was investigated through stress relaxation tests and the corresponding relaxation time distribution spectra. Elastin was incubated in 2M glucose solution at 37°C for 4, 7, 14, 21 or 28 days. Biaxial stress relaxation tests were performed to study the viscoelastic property of elastin. Elastin samples with glucose treatment show increased stress relaxation with incubation time. Continuous relaxation time distribution spectra were obtained from the stress relaxation data using Tikhonov regularization method. Generally the spectra of both untreated and treated elastin have a broad range of relaxation time constants and multiple peaks located between 0.1-10,000s. The intensity of the short-term peak (0.1-10s) increases after glucose exposure whereas the intensity of the long-term peak (> 100s) decreases. The dominant peaks, i.e., the long-term peak of untreated tissue and the short-term peak of glucose treated tissue, suggest different relaxation mechanisms. The initial stress level dependency of stress relaxation was studied and the results suggested that the intensity of all the peaks increases with higher initial stresses. A multi-exponential model was developed to describe the stress relaxation behavior with material parameters obtained directly from the continuous relaxation spectrum. To fully characterize the relaxation processes, a multi-exponential model with four exponential terms, located between 0.001-1s, 1-10s, 10-100s, and 100-10,000s and obtained directly from the corresponding relaxation spectrum

  9. The relationship between the particle properties, mechanical behavior, and surface roughness of some pharmaceutical excipient compacts

    International Nuclear Information System (INIS)

    Narayan, Padma; Hancock, Bruno C.

    2003-01-01

    Several common pharmaceutical excipient powders were compacted at a constant solid fraction (SF) in order to study the relationship between powder properties, compact surface roughness, and compact mechanical properties such as hardness, elasticity, and brittleness. The materials used in this study included microcrystalline cellulose (MCC), fumaric acid, mannitol, lactose monohydrate, spray dried lactose, sucrose, and dibasic calcium phosphate dihydrate. A slow consolidation process was used to make compacts at a SF of 0.85 (typical for most pharmaceutical tablets) from single excipient components. A model was proposed to describe the surface roughness of compacts based on the brittle or ductile deformation tendencies of the powder materials. The roughness profile would also be dependent upon the magnitude of the compression stress in relation to the yield stress (onset of irreversible deformation) values of the excipients. It was hypothesized that brittle materials would produce smooth compacts with high surface variability due to particle fracture, and the converse would apply for ductile materials. Compact surfaces should be smoother if the materials were compressed above their yield pressure values. Non-contact optical profilometry was used along with scanning electron microscopy to quantify and characterize the surface morphology of the excipient compacts. The roughness parameters R a (average roughness), R q (RMS roughness), R q /R a (ratio describing surface variability), and R sk (skewness) were found to correlate with the deformation properties of the excipients. Brittle materials such as lactose, sucrose, and calcium phosphate produced compacts with low values of R a and R q , high variability, and negative R sk . The opposite was found with plastic materials such as MCC, mannitol, and fumaric acid. The highly negative skewness values for brittle material compacts may indicate their propensity to be vulnerable to cracks or surface defects. These findings

  10. Self-care behaviour for minor symptoms: can Andersen's Behavioral Model of Health Services Use help us to understand it?

    Science.gov (United States)

    Porteous, Terry; Wyke, Sally; Hannaford, Philip; Bond, Christine

    2015-02-01

    To explore whether Andersen's Behavioral Model of Health Services Use can aid understanding of self-care behaviour and inform development of interventions to promote self-care for minor illness. Qualitative interviews were conducted with 24 Scottish participants about their experience and management of minor symptoms normally associated with analgesic use. Synthesised data from the interviews were mapped onto the Behavioral Model. All factors identified as influencing decisions about how to manage the symptoms discussed, mapped onto at least one domain of Andersen's model. Individual characteristics including beliefs, need factors and available resources were associated with health behaviour, including self-care. Outcomes such as perceived health status and consumer satisfaction from previous experience of managing symptoms also appeared to feed back into health behaviour. The Behavioral Model seems relevant to self-care as well as formal health services. Additional work is needed to explore applicability of the Behavioral Model to different types of symptoms, different modalities of self-care and in countries with different health care systems. Future quantitative studies should establish the relative importance of factors influencing the actions people take to manage minor symptoms to inform future interventions aimed at optimising self-care behaviour. © 2014 Royal Pharmaceutical Society.

  11. Progress in understanding the mechanical behavior of pressure-vessel materials at elevated temperatures

    International Nuclear Information System (INIS)

    Swindeman, R.W.; Brinkman, C.R.

    1981-01-01

    Progress during the 1970's on the production of high-temperature mechanical properties data for pressure vessel materials was reviewed. The direction of the research was toward satisfying new data requirements to implement advances in high-temperature inelastic design methods. To meet these needs, servo-controlled testing machines and high-resolution extensometry were developed to gain more information on the essential behavioral features of high-temperature alloys. The similarities and differences in the mechanical response of various pressure vessel materials were identified. High-temperature pressure vessel materials that have received the most attention included Type 304 stainless steel, Type 316 stainless steel, 2 1/4 Cr-1 Mo steel, alloy 800H, and Hastelloy X

  12. Physical Chemistry of Nanomedicine: Understanding the Complex Behaviors of Nanoparticles in Vivo

    Science.gov (United States)

    Lane, Lucas A.; Qian, Ximei; Smith, Andrew M.; Nie, Shuming

    2015-04-01

    Nanomedicine is an interdisciplinary field of research at the interface of science, engineering, and medicine, with broad clinical applications ranging from molecular imaging to medical diagnostics, targeted therapy, and image-guided surgery. Despite major advances during the past 20 years, there are still major fundamental and technical barriers that need to be understood and overcome. In particular, the complex behaviors of nanoparticles under physiological conditions are poorly understood, and detailed kinetic and thermodynamic principles are still not available to guide the rational design and development of nanoparticle agents. Here we discuss the interactions of nanoparticles with proteins, cells, tissues, and organs from a quantitative physical chemistry point of view. We also discuss insights and strategies on how to minimize nonspecific protein binding, how to design multistage and activatable nanostructures for improved drug delivery, and how to use the enhanced permeability and retention effect to deliver imaging agents for image-guided cancer surgery.

  13. Explanatory models of black lung: understanding the health-related behavior of Appalachian coal miners.

    Science.gov (United States)

    Friedl, J

    1982-03-01

    Many retired coal miners who are eligible for care in a black lung treatment center at little or no cost to themselves do not enter into available programs or discontinue soon after beginning therapy. Reasons for this behavior are related to the prevalent beliefs among Appalachians concerning the course of black lung and the appropriate treatment for it. The miners' health beliefs are clearly at odds with those of the health care providers who work in the centers. Using the concept of explanatory model, popular and professional health cultures are analyzed, focusing on course of disease, sick role, appropriate treatment, and expected outcome. Differences in explanatory models are discussed with regard to implications for the organization and delivery of care to retired coal miners with black lung.

  14. Understanding the intentional acoustic behavior of humpback whales: a production-based approach.

    Science.gov (United States)

    Cazau, Dorian; Adam, Olivier; Laitman, Jeffrey T; Reidenberg, Joy S

    2013-09-01

    Following a production-based approach, this paper deals with the acoustic behavior of humpback whales. This approach investigates various physical factors, which are either internal (e.g., physiological mechanisms) or external (e.g., environmental constraints) to the respiratory tractus of the whale, for their implications in sound production. This paper aims to describe a functional scenario of this tractus for the generation of vocal sounds. To do so, a division of this tractus into three different configurations is proposed, based on the air recirculation process which determines air sources and laryngeal valves. Then, assuming a vocal function (in sound generation or modification) for several specific anatomical components, an acoustic characterization of each of these configurations is proposed to link different spectral features, namely, fundamental frequencies and formant structures, to specific vocal production mechanisms. A discussion around the question of whether the whale is able to fully exploit the acoustic potential of its respiratory tractus is eventually provided.

  15. A Multi-Method Approach to Understanding Behavior Change. The Case of Texting and Driving

    Directory of Open Access Journals (Sweden)

    Karen M. HOOD

    2017-12-01

    Full Text Available Distracted driving, specifically texting and driving, has become a nationwide public health problem in the U.S. with negative, and potentially fatal consequences. In an effort to combat the growing problem, non-profit organizations, corporations, and the federal government have all stepped in to try to increase public awareness and persuade drivers to cease texting while driving. These efforts have not had the desired impact as texting and driving has continued to increase in recent years. This research investigates the potential that the messages used to curb texting and driving behavior might not be properly constructed. Specifically, we test the potential for message sponsor and self-relevance of the message to influence message outcomes. Our results suggest that messages sponsored by a combination of company and government that are self-relevant to viewers will have different outcomes than other messages. We identify practical and theoretical implications as well as future research directions.

  16. Applying Ecodevelopmental Theory and the Theory of Reasoned Action to Understand HIV Risk Behaviors Among Hispanic Adolescents.

    Science.gov (United States)

    Ortega, Johis; Huang, Shi; Prado, Guillermo

    2012-01-03

    HIV/AIDS is listed as one of the top 10 reasons for the death of Hispanics between the ages of 15 and 54 in the United States. This cross sectional, descriptive secondary study proposed that using both the systemic (ecodevelopmental) and the individually focused (theory of reasoned action) theories together would lead to an increased understanding of the risk and protective factors that influence HIV risk behaviors in this population. The sample consisted of 493 Hispanic adolescent 7th and 8th graders and their immigrant parents living in Miami, Florida. Structural Equation Modeling (SEM) was used for the data analysis. Family functioning emerged as the heart of the model, embedded within a web of direct and mediated relationships. The data support the idea that family can play a central role in the prevention of Hispanic adolescents' risk behaviors.

  17. Understanding parental behavior in pediatric palliative care: Attachment theory as a paradigm.

    Science.gov (United States)

    Kearney, Joan A; Byrne, Mary W

    2015-12-01

    The objective of this conceptual paper was to present important constructs in attachment theory as they apply to parent and caregiver behavior in pediatric palliative care. Clarification of these constructs is provided with specific reference to their clinical application as well as their reflection in current empirical literature. Social attachment theory is proposed as a developmentally contextual model for the study of parenting in pediatric palliative and end-of-life care. A comprehensive search was conducted of pertinent literatures. These included classic as well as recent theory and research in attachment theory in addition to the empirical literatures on parent and family experience in pediatric palliative care, serious illness, and beyond to parental bereavement. Other relevant literature was examined with respect to the phenomena of concern. The empirical literature in pediatric palliative care supports the use of central concepts in attachment theory as foundational for further inquiry. This is evidenced in the emphasis on the importance of parental protection of the child, as well as executive activities such as decision making and other prominent parental operations, parental psychological resolution of the child's diagnosis and illness as well as coping and meaning making, and the core significance of parental relationships with providers who provide secure-base and safe-haven functions. The promise for developing integrated, conceptually based interventions from construction through implementation is of urgent importance to children and families receiving pediatric palliative care services. Focusing on key parental behaviors and processes within the context of a well-studied and contextually appropriate model will inform this task efficiently. The attachment paradigm meets these criteria and has promise in allowing us to move forward in developing well-defined, inclusive, and conceptually grounded protocols for child and family psychosocial research

  18. Understanding Spatiotemporal Patterns of Biking Behavior by Analyzing Massive Bike Sharing Data in Chicago.

    Directory of Open Access Journals (Sweden)

    Xiaolu Zhou

    Full Text Available The growing number of bike sharing systems (BSS in many cities largely facilitates biking for transportation and recreation. Most recent bike sharing systems produce time and location specific data, which enables the study of travel behavior and mobility of each individual. However, despite a rapid growth of interest, studies on massive bike sharing data and the underneath travel pattern are still limited. Few studies have explored and visualized spatiotemporal patterns of bike sharing behavior using flow clustering, nor examined the station functional profiles based on over-demand patterns. This study investigated the spatiotemporal biking pattern in Chicago by analyzing massive BSS data from July to December in 2013 and 2014. The BSS in Chicago gained more popularity. About 15.9% more people subscribed to this service. Specifically, we constructed bike flow similarity graph and used fastgreedy algorithm to detect spatial communities of biking flows. By using the proposed methods, we discovered unique travel patterns on weekdays and weekends as well as different travel trends for customers and subscribers from the noisy massive amount data. In addition, we also examined the temporal demands for bikes and docks using hierarchical clustering method. Results demonstrated the modeled over-demand patterns in Chicago. This study contributes to offer better knowledge of biking flow patterns, which was difficult to obtain using traditional methods. Given the trend of increasing popularity of the BSS and data openness in different cities, methods used in this study can extend to examine the biking patterns and BSS functionality in different cities.

  19. Understanding persuasion contexts in health gamification: A systematic analysis of gamified health behavior change support systems literature.

    Science.gov (United States)

    Alahäivälä, Tuomas; Oinas-Kukkonen, Harri

    2016-12-01

    Gamification is increasingly used as a design strategy when developing behavior change support systems in the healthcare domain. It is commonly agreed that understanding the contextual factors is critical for successful gamification, but systematic analyses of the persuasive contexts have been lacking so far within gamified health intervention studies. Through a persuasion context analysis of the gamified health behavior change support systems (hBCSSs) literature, we inspect how the contextual factors have been addressed in the prior gamified health BCSS studies. The implications of this study are to provide the practitioners and researchers examples of how to conduct a systematic analysis to help guide the design and research on gamified health BCSSs. The ideas derived from the analysis of the included studies will help identify potential pitfalls and shortcomings in both the research and implementations of gamified health behavior change support systems. We systematically analyzed the persuasion contexts of 15 gamified health intervention studies. According to our results, gamified hBCSSs are implemented under different facets of lifestyle change and treatments compliance, and use a multitude of technologies and methods. We present a set of ideas and concepts to help improve endeavors in studying gamified health intervention through comprehensive understanding of the persuasive contextual factors. Future research on gamified hBCSSs should systematically compare the different combinations of contextual factors, related theories, chosen gamification strategies, and the study of outcomes to help understand how to achieve the most efficient use of gamification on the different aspects of healthcare. Analyzing the persuasion context is essential to achieve this. With the attained knowledge, those planning health interventions can choose the 'tried-and-tested' approaches for each particular situation, rather than develop solutions in an ad-hoc manner. Copyright © 2016

  20. Utilizing E. coli Autotactic Responses to Understand Quorum Dependent Behaviors in P. aeruginosa

    Science.gov (United States)

    Strain, Shinji; Bienvenu, Samuel; Thatcher, Travis; Gordon, Vernita

    2010-10-01

    Biofilms are multicellular, surface-bound communities of interacting unicellular organisms. In the initial stages of biofilm formation, cells populate the surface and eventually form microcolonies (dense surface-bound clusters of cells). How much these microcolonies arise from clonal growth and how much they arise from attraction and binding of non-clonal cells is not well-understood. A potentially important form of attraction is autotaxis, movement of cells toward like cells. Using microscopy and automated tracking and analysis algorithms, we will study how bacteria respond to each other in a spatially-dependent manner. We will determinine how variations in neighbor density and arrangement stimulate changes in cell motility. E. coli will be our initial model system, and later we will probe early biofilm formation in P. aeruginosa. We will also study chemotaxis (motility toward an attractive chemical), to understand how this drives, complements, or competes with autotaxis in different settings.

  1. Understanding volatility correlation behavior with a magnitude cross-correlation function

    Science.gov (United States)

    Jun, Woo Cheol; Oh, Gabjin; Kim, Seunghwan

    2006-06-01

    We propose an approach for analyzing the basic relation between correlation properties of the original signal and its magnitude fluctuations by decomposing the original signal into its positive and negative fluctuation components. We use this relation to understand the following phenomenon found in many naturally occurring time series: the magnitude of the signal exhibits long-range correlation, whereas the original signal is short-range correlated. The applications of our approach to heart rate variability signals and high-frequency foreign exchange rates reveal that the difference between the correlation properties of the original signal and its magnitude fluctuations is induced by the time organization structure of the correlation function between the magnitude fluctuations of positive and negative components. We show that this correlation function can be described well by a stretched-exponential function and is related to the nonlinearity and the multifractal structure of the signals.

  2. Identifying and Understanding Environment-Induced Crack propagation Behavior in Ni-based Superalloy INCONEL 617

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Longzhou

    2012-11-30

    The nickel-based superalloy INCONEL 617 is a candidate material for heat exchanger applications in the next-generation nuclear plant (NGNP) system. This project will study the crack propagation process of alloy 617 at temperatures of 650°C-950°C in air under static/cyclic loading conditions. The goal is to identify the environmental and mechanical damage components and to understand in-depth the failure mechanism. Researchers will measure the fatigue crack propagation (FCP) rate (da/dn) under cyclic and hold-time fatigue conditions, and sustained crack growth rates (da/dt) at elevated temperatures. The independent FCP process will be identified and the rate-controlled sustained loading crack process will be correlated with the thermal activation equation to estimate the oxygen thermal activation energy. The FCP-dependent model indicates that if the sustained loading crack growth rate, da/dt, can be correlated with the FCP rate, da/dn, at the full time dependent stage, researchers can confirm stress-accelerated grain-boundary oxygen embrittlement (SAGBOE) as a predominate effect. Following the crack propagation tests, the research team will examine the fracture surface of materials in various cracking stages using a scanning electron microscope (SEM) and an optical microscope. In particular, the microstructure of the crack tip region will be analyzed in depth using high resolution transmission electron microscopy (TEM) and electron energy loss spectrum (EELS) mapping techniques to identify oxygen penetration along the grain boundary and to examine the diffused oxygen distribution profile around the crack tip. The cracked sample will be prepared by focused ion beam nanofabrication technology, allowing researchers to accurately fabricate the TEM samples from the crack tip while minimizing artifacts. Researchers will use these microscopic and spectroscopic results to interpret the crack propagation process, as well as distinguish and understand the environment or

  3. Particle transport and deposition: basic physics of particle kinetics.

    Science.gov (United States)

    Tsuda, Akira; Henry, Frank S; Butler, James P

    2013-10-01

    The human body interacts with the environment in many different ways. The lungs interact with the external environment through breathing. The enormously large surface area of the lung with its extremely thin air-blood barrier is exposed to particles suspended in the inhaled air. The particle-lung interaction may cause deleterious effects on health if the inhaled pollutant aerosols are toxic. Conversely, this interaction can be beneficial for disease treatment if the inhaled particles are therapeutic aerosolized drugs. In either case, an accurate estimation of dose and sites of deposition in the respiratory tract is fundamental to understanding subsequent biological response, and the basic physics of particle motion and engineering knowledge needed to understand these subjects is the topic of this article. A large portion of this article deals with three fundamental areas necessary to the understanding of particle transport and deposition in the respiratory tract. These are: (i) the physical characteristics of particles, (ii) particle behavior in gas flow, and (iii) gas-flow patterns in the respiratory tract. Other areas, such as particle transport in the developing lung and in the diseased lung are also considered. The article concludes with a summary and a brief discussion of areas of future research. © 2013 American Physiological Society. Compr Physiol 3:1437-1471, 2013.

  4. Particle track record in lunar silicates: long-term behavior of solar and galactic VH nuclei and lunar surface dynamics

    International Nuclear Information System (INIS)

    Yuhas, D.E.

    1974-01-01

    Stored nuclear particle tracks are abundant in all major mineral phases found on the moon. The track production in the near surface regions (depth less than 1 mm) is dominated by VH (Z greater than 20) cosmic rays of solar origin. At deeper depths (greater than 5 mm) heavy galactic cosmic rays dominate the production. The track profile (track density vs depth) is shaped by both the energy spectrum of impinging VH nuclei and dynamical processes which change rock surfaces with time. The analyses of track records in a number of lunar rocks with different surface exposure histories yield information about both dynamical processes on the moon and the long-term time behavior of solar and galactic cosmic rays. (Diss. Abstr. Int., B)

  5. Using the internet to understand angler behavior in the information age

    Science.gov (United States)

    Martin, Dustin R.; Pracheil, Brenda M.; DeBoer, Jason A.; Wilde, Gene R.; Pope, Kevin L.

    2012-01-01

    Declining participation in recreational angling is of great concern to fishery managers because fishing license sales are an important revenue source for protection of aquatic resources. This decline is frequently attributed, in part, to increased societal reliance on electronics. Internet use by anglers is increasing and fishery managers may use the Internet as a unique means to increase angler participation. We examined Internet search behavior using Google Insights for Search, a free online tool that summarizes Google searches from 2004 to 2011 to determine (1) trends in Internet search volume for general fishing related terms and (2) the relative usefulness of terms related to angler recruitment programs across the United States. Though search volume declined for general fishing terms (e.g., fishing, fishing guide), search volume increased for social media and recruitment terms (e.g., fishing forum, family fishing) over the 7-year period. We encourage coordinators of recruitment programs to capitalize on anglers’ Internet usage by considering Internet search patterns when creating web-based information. Careful selection of terms used in web-based information to match those currently searched by potential anglers may help to direct traffic to state agency websites that support recruitment efforts.

  6. Investigating hygroscopic behavior and phase separation of organic/inorganic mixed phase aerosol particles with FTIR spectroscopy

    Science.gov (United States)

    Zawadowicz, M. A.; Cziczo, D. J.

    2013-12-01

    Atmospheric aerosol particles can be composed of inorganic salts, such as ammonium sulfate and sodium chloride, and therefore exhibit hygroscopic properties. Many inorganic salts have very well-defined deliquescence and efflorescence points at which they take up and lose water, respectively. For example, the deliquescence relative humidity of pure ammonium sulfate is about 80% and its efflorescence point is about 35%. This behavior of ammonium sulfate is important to atmospheric chemistry because some reactions, such as the hydrolysis of nitrogen pentoxide, occur on aqueous but not crystalline surfaces. Deliquescence and efflorescence of simple inorganic salt particles have been investigated by a variety of methods, such as IR spectroscopy, tandem mobility analysis and electrodynamic balance. Field measurements have shown that atmospheric aerosol are not typically a single inorganic salt, instead they often contain organic as well as inorganic species. Mixed inorganic/organic aerosol particles, while abundant in the atmosphere, have not been studied as extensively. Many recent studies have focused on microscopy techniques that require deposition of the aerosol on a glass slide, possibly changing its surface properties. This project investigates the deliquescence and efflorescence points, phase separation and ability to exchange gas-phase components of mixed organic and inorganic aerosol using a flow tube coupled with FTIR spectroscopy. Ammonium sulfate aerosol mixed with organic polyols with different O:C ratios, including glycerol, 1,2,6-hexanetriol, 1,4-butanediol and 1,5-pentanediol have been investigated. This project aims to study gas-phase exchange in these aerosol systems to determine if exchange is impacted when phase separation occurs.

  7. Nanoparticles Decorated on Resin Particles and Their Flame Retardancy Behavior for Polymer Composites

    Directory of Open Access Journals (Sweden)

    Nour F. Attia

    2017-01-01

    Full Text Available New nanocomposites have been developed by doping of amberlite IR120 resin with spherical TiO2 nanoparticles in the presence of maleate diphosphate. Polystyrene composites of resin, maleate diphosphate, and resin-maleate diphosphate were prepared individually. This is in addition to preparation of polymer nanocomposites of polystyrene-resin doped TiO2 nanoparticles-maleate diphosphate. The flame retardancy and thermal stability properties of these developed polymer composites were evaluated. The inclusion of resin and resin doped nanoparticles improved the fire retardant behavior of polystyrene composites and enhanced their thermal stability. Synergistic behavior between flame retardant, resin, and nanoparticles was detected. The rate of burning of the polymer nanocomposites was recorded as 10.7 mm/min achieving 77% reduction compared to pure polystyrene (46.5 mm/min. The peak heat release rate (PHRR of the new polymer composites has reduced achieving 46% reduction compared to blank polymer. The morphology and dispersion of nanoparticles on resin and in polymer nanocomposites were characterized using transmission and scanning electron microscopy, respectively. The flame retardancy and thermal properties were evaluated using UL94 flame chamber, cone tests, and thermogravimetric analysis, respectively.

  8. Characteristic rotational behaviors of rod-shaped cargo revealed by automated five-dimensional single particle tracking.

    Science.gov (United States)

    Chen, Kuangcai; Gu, Yan; Sun, Wei; Bin Dong; Wang, Gufeng; Fan, Xinxin; Xia, Tian; Fang, Ning

    2017-10-12

    We report an automated single particle tracking technique for tracking the x, y, z coordinates, azimuthal and elevation angles of anisotropic plasmonic gold nanorod probes in live cells. These five spatial coordinates are collectively referred to as 5D. This method overcomes a long-standing challenge in distinguishing rotational motions from translational motions in the z-axis in differential interference contrast microscopy to result in full disclosure of nanoscale motions with high accuracy. Transferrin-coated endocytic gold nanorod cargoes initially undergo active rotational diffusion and display characteristic rotational motions on the membrane. Then as the cargoes being enclosed in clathrin-coated pits, they slow down the active rotation and experience a quiet period before they restore active rotational diffusion after fission and eventually being transported away from the original entry spots. Finally, the 3D trajectories and the accompanying rotational motions of the cargoes are resolved accurately to render the intracellular transport process in live cells.Distinguishing rotational motions from translational motions in the z-axis has been a long-standing challenge. Here the authors develop a five-dimensional single particle tracking method to detect rotational behaviors of nanocargos during clathrin-mediated endocytosis and intracellular transport.

  9. Probabilistic methods for the simulation of fuel particles behavior under irradiation

    International Nuclear Information System (INIS)

    Cannamela, C.

    2007-09-01

    This work is devoted to the evaluation of mathematical expectations in the context of structural reliability. We seek a failure probability estimate (that we assume low), taking into account the uncertainty of influential parameters of the System. Our goal is to reach a good compromise between the accuracy of the estimate and the associated computational cost. This approach is used to estimate the failure probability of fuel particles from a HTR-type nuclear reactor. This estimate is obtain by means of costly numerical simulations. We consider different probabilistic methods to tackle the problem. First, we consider a variance reducing Monte Carlo method: importance sampling. For the parametric case, we propose adaptive algorithms in order to build a series of probability densities that will eventually converge to optimal importance density. We then present several estimates of the mathematical expectation based on this series of densities. Next, we consider a multi-level method using Monte Carlo Markov Chain algorithm. Finally, we turn our attention to the related problem of quantile estimation (non extreme) of physical output from a large-scale numerical code. We propose a controlled stratification method. The random input parameters are sampled in specific regions obtained from surrogate of the response. The estimation of the quantile is then computed from this sample. (author)

  10. Study on protein conformation and adsorption behaviors in nanodiamond particle-protein complexes

    Energy Technology Data Exchange (ETDEWEB)

    Wang Haidong [Department of Biomedical Engineering, University of Saskatchewan, Saskatoon, S7N 5A9 (Canada); Niu, Catherine Hui [Department of Chemical Engineering, University of Saskatchewan, Saskatoon, S7N 5A9 (Canada); Yang Qiaoqin [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, S7N 5A9 (Canada); Badea, Ildiko, E-mail: catherine.niu@usask.ca [Drug Design and Discovery Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, S7N 5C9 (Canada)

    2011-04-08

    In the present research, the conformation of bovine serum albumin (BSA) in the nanodiamond particle (ND)-BSA complex was studied by Fourier transform infrared spectroscopy, fluorescence spectroscopy, UV-vis spectroscopy, and circular dichroism spectroscopy. The spectroscopic study revealed that most BSA structural features could be preserved in the complex though the BSA underwent conformational changes in the complex due to ND-BSA interaction. In addition, BSA adsorption isotherms and zeta-potential measurements were employed to investigate the pH dependence of the ND-BSA interaction. The changes in surface charge of the ND-BSA complex with pH variations indicated that the binding of BSA to ND might lead to not only the adsorption of BSA onto the ND surface but also the partial breakup of ND aggregates into relatively small ND-BSA aggregates because of the strong binding force between ND and BSA. The results show that ND is an excellent platform for protein immobilization with high affinity and holds great potential to be used for biosensor applications.

  11. Discovering and understanding android sensor usage behaviors with data flow analysis

    KAUST Repository

    Liu, Xing

    2017-03-20

    Today’s Android-powered smartphones have various embedded sensors that measure the acceleration, orientation, light and other environmental conditions. Many functions in the third-party applications (apps) need to use these sensors. However, embedded sensors may lead to security issues, as the third-party apps can read data from these sensors without claiming any permissions. It has been proven that embedded sensors can be exploited by well designed malicious apps, resulting in leaking users’ privacy. In this work, we are motivated to provide an overview of sensor usage patterns in current apps by investigating what, why and how embedded sensors are used in the apps collected from both a Chinese app. market called “AppChina” and the official market called “Google Play”. To fulfill this goal, We develop a tool called “SDFDroid” to identify the used sensors’ types and to generate the sensor data propagation graphs in each app. We then cluster the apps to find out their sensor usage patterns based on their sensor data propagation graphs. We apply our method on 22,010 apps collected from AppChina and 7,601 apps from Google Play. Extensive experiments are conducted and the experimental results show that most apps implement their sensor related functions by using the third-party libraries. We further study the sensor usage behaviors in the third-party libraries. Our results show that the accelerometer is the most frequently used sensor. Though many third-party libraries use no more than four types of sensors, there are still some third-party libraries registering all the types of sensors recklessly. These results call for more attentions on better regulating the sensor usage in Android apps.

  12. Understanding the Role of Context-Specific Drinking in Neglectful Parenting Behaviors.

    Science.gov (United States)

    Freisthler, Bridget; Wolf, Jennifer Price; Johnson-Motoyama, Michelle

    2015-09-01

    Child neglect is the most common form of child maltreatment, yet little is known about how drinking context may be related to particular subtypes of child neglect. This study examines the relationship between parental drinking in multiple contexts and the use of supervisory and physical neglectful. A sample of 2152 parents of children 12 years or younger in 50 cities in California was obtained using a computer-assisted telephone interview. Past-year prevalence of child neglect was measured using the Multidimensional Neglectful Behavior Scale. Information was collected on past month or past-year frequency of having at least one drink in five contexts, continued drinking measures (e.g. number of drinks after the first drink) and sociodemographics. Data were analyzed using multilevel random effects logit models. Frequency of drinking in various contexts was related to different neglect subtypes. Specifically, frequency of drinking with friends was positively related leaving a child home alone when an adult should be present. Parents who drank more frequently with family were less likely to leave their child home alone in the past year yet more likely to unsafely monitor their child in the past year. Drinking at parties more often was related to being more likely to leave a child alone in a car sometime during the past year. That no single drinking context is universally problematic for supervisory and physical neglect suggests that different social mechanisms may underlie the relationships observed between different drinking contexts and neglect subtypes. © The Author 2015. Medical Council on Alcohol and Oxford University Press. All rights reserved.

  13. Understanding Health Seeking Behavior Of Health Care Professionals In Tertiary Care Hospitals In Pakistan.

    Science.gov (United States)

    Bana, Shazia; Yakoob, Javed; Jivany, Nourin; Faisal, Asima; Jawed, Humeira; Awan, Safia

    2016-01-01

    Health seeking behaviour refers to the behaviour of people towards seeking their own health through provided health services. The medical professionals are at a higher risk of avoiding health seeking behaviour because they believe they are aware of the diseases and their symptoms as well as the pharmaceutical management of the disease. The aim of this study was to understand the healthcare seeking behaviour of nurses and doctors as well as the factors affecting it in hospitals of a major city in a developing country. A cross-sectional study was designed and a self-report questionnaire was distributed to healthcare workers at four tertiary care hospitals from July, 2012 to December, 2014. A total of 1015 participants responded. There were 234 (23%) doctors, 664 (65%) nurses, 60 (6%) pharmacist and 57 (6%) paramedical staff. The doctors 194 (83%) had a greater access to medical facilities compared to nurses 278 (42%) (phealth compared to doctors 102 (44%) (phealth check-ups compared to doctor 234 (100%) (pseek healthcare when they get sick. Self-medication is common in both groups.

  14. Understanding the nanoscale redox-behavior of iron-anodes for rechargeable iron-air batteries

    Energy Technology Data Exchange (ETDEWEB)

    Weinrich, Henning [Forschungszentrum Julich (Germany). Inst. for Energy and Climate Research-Fundamental Electrochemistry (IEK-9); RWTH Aachen Univ., Aachen (Germany). Inst. of Physical Chemistry; Come, Jérémy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Tempel, Hermann [Forschungszentrum Julich (Germany). Inst. for Energy and Climate Research-Fundamental Electrochemistry (IEK-9); Kungl, Hans [Forschungszentrum Julich (Germany). Inst. for Energy and Climate Research-Fundamental Electrochemistry (IEK-9); Eichel, Rüdiger-A. [Forschungszentrum Julich (Germany). Inst. for Energy and Climate Research-Fundamental Electrochemistry (IEK-9); Balke, Nina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)

    2017-10-10

    Iron-air cells provide a promising and resource-efficient alternative battery concept with superior area specific power density characteristics compared to state-of-the-art Li-air batteries and potentially superior energy density characteristics compared to present Li-ion batteries. Understanding charge-transfer reactions at the anode-electrolyte interface is the key to develop high-performance cells. By employing in-situ electrochemical atomic force microscopy (in-situ EC-AFM), in-depth insight into the electrochemically induced surface reaction processes on iron in concentrated alkaline electrolyte is obtained. The results highlight the formation and growth of the redox-layer on iron over the course of several oxidation/reduction cycles. By this means, a direct correlation between topography changes and the corresponding electrochemical reactions at the nanoscale could unambiguously be established. Here in this paper, the twofold character of the nanoparticulate redox-layer in terms of its passivating character and its contribution to the electrochemical reactions is elucidated. Furthermore, the evolution of single nanoparticles on the iron electrode surface is evaluated in unprecedented and artifact-free detail. Based on the dedicated topography analysis, a detailed structural model for the evolution of the redox-layer which is likewise elementary for corrosion science and battery research is derived.

  15. Making big communities small: using network science to understand the ecological and behavioral requirements for community social capital.

    Science.gov (United States)

    Neal, Zachary

    2015-06-01

    The concept of social capital is becoming increasingly common in community psychology and elsewhere. However, the multiple conceptual and operational definitions of social capital challenge its utility as a theoretical tool. The goals of this paper are to clarify two forms of social capital (bridging and bonding), explicitly link them to the structural characteristics of small world networks, and explore the behavioral and ecological prerequisites of its formation. First, I use the tools of network science and specifically the concept of small-world networks to clarify what patterns of social relationships are likely to facilitate social capital formation. Second, I use an agent-based model to explore how different ecological characteristics (diversity and segregation) and behavioral tendencies (homophily and proximity) impact communities' potential for developing social capital. The results suggest diverse communities have the greatest potential to develop community social capital, and that segregation moderates the effects that the behavioral tendencies of homophily and proximity have on community social capital. The discussion highlights how these findings provide community-based researchers with both a deeper understanding of the contextual constraints with which they must contend, and a useful tool for targeting their efforts in communities with the greatest need or greatest potential.

  16. Temporal behavior of neutral particle fluxes in TFTR (Tokamak Fusion Test Reactor) neutral beam injectors

    Energy Technology Data Exchange (ETDEWEB)

    Kamperschroer, J.H.; Gammel, G.M.; Roquemore, A.L.; Grisham, L.R.; Kugel, H.W.; Medley, S.S.; O' Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1989-09-01

    Data from an E {parallel} B charge exchange neutral analyzer (CENA), which views down the axis of a neutral beamline through an aperture in the target chamber calorimeter of the TFTR neutral beam test facility, exhibit two curious effects. First, there is a turn-on transient lasting tens of milliseconds having a magnitude up to three times that of the steady-state level. Second, there is a 720 Hz, up to 20% peak-to-peak fluctuation persisting the entire pulse duration. The turn-on transient occurs as the neutralizer/ion source system reaches a new pressure equilibrium following the effective ion source gas throughput reduction by particle removal as ion beam. Widths of the transient are a function of the gas throughput into the ion source, decreasing as the gas supply rate is reduced. Heating of the neutalizer gas by the beam is assumed responsible, with gas temperature increasing as gas supply rate is decreased. At low gas supply rates, the transient is primarliy due to dynamic changes in the neutralizer line density and/or beam species composition. Light emission from the drift duct corroborate the CENA data. At high gas supply rates, dynamic changes in component divergence and/or spatial profiles of the source plasma are necessary to explain the observations. The 720 Hz fluctuation is attributed to a 3% peak-to-peak ripple of 720 Hz on the arc power supply amplified by the quadratic relationship between beam divergence and beam current. Tight collimation by CENA apertures cause it to accept a very small part of the ion source's velocity space, producing a signal linearly proportional to beam divergence. Estimated fluctuations in the peak power density delivered to the plasma under these conditions are a modest 3--8% peak to peak. The efffects of both phenomena on the injected neutral beam can be ameliorated by careful operion of the ion sources. 21 refs., 11 figs., 2 tabs.

  17. Temporal behavior of neutral particle fluxes in TFTR [Tokamak Fusion Test Reactor] neutral beam injectors

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Gammel, G.M.; Roquemore, A.L.

    1989-09-01

    Data from an E parallel B charge exchange neutral analyzer (CENA), which views down the axis of a neutral beamline through an aperture in the target chamber calorimeter of the TFTR neutral beam test facility, exhibit two curious effects. First, there is a turn-on transient lasting tens of milliseconds having a magnitude up to three times that of the steady-state level. Second, there is a 720 Hz, up to 20% peak-to-peak fluctuation persisting the entire pulse duration. The turn-on transient occurs as the neutralizer/ion source system reaches a new pressure equilibrium following the effective ion source gas throughput reduction by particle removal as ion beam. Widths of the transient are a function of the gas throughput into the ion source, decreasing as the gas supply rate is reduced. Heating of the neutalizer gas by the beam is assumed responsible, with gas temperature increasing as gas supply rate is decreased. At low gas supply rates, the transient is primarliy due to dynamic changes in the neutralizer line density and/or beam species composition. Light emission from the drift duct corroborate the CENA data. At high gas supply rates, dynamic changes in component divergence and/or spatial profiles of the source plasma are necessary to explain the observations. The 720 Hz fluctuation is attributed to a 3% peak-to-peak ripple of 720 Hz on the arc power supply amplified by the quadratic relationship between beam divergence and beam current. Tight collimation by CENA apertures cause it to accept a very small part of the ion source's velocity space, producing a signal linearly proportional to beam divergence. Estimated fluctuations in the peak power density delivered to the plasma under these conditions are a modest 3--8% peak to peak. The efffects of both phenomena on the injected neutral beam can be ameliorated by careful operion of the ion sources. 21 refs., 11 figs., 2 tabs

  18. Understanding of the mechanical and structural changes induced by alpha particles and heavy ions in the French simulated nuclear waste glass

    International Nuclear Information System (INIS)

    Karakurt, G.; Abdelouas, A.; Guin, J.-P.; Nivard, M.; Sauvage, T.; Paris, M.; Bardeau, J.-F.

    2016-01-01

    Borosilicate glasses are considered for the long-term confinement of high-level nuclear wastes. External irradiations with 1 MeV He + ions and 7 MeV Au 5+ ions were performed to simulate effects produced by alpha particles and by recoil nuclei in the simulated SON68 nuclear waste glass. To better understand the structural modifications, irradiations were also carried out on a 6-oxides borosilicate glass, a simplified version of the SON68 glass (ISG glass). The mechanical and macroscopic properties of the glasses were studied as function of the deposited electronic and nuclear energies. Alpha particles and gold ions induced a volume change up to −0.7% and −2.7%, respectively, depending on the glass composition. Nano-indentations tests were used to determine the mechanical properties of the irradiated glasses. A decrease of about −22% to −38% of the hardness and a decrease of the reduced Young's modulus by −8% were measured after irradiations. The evolution of the glass structure was studied by Raman spectroscopy, and also 11 B and 27 Al Nuclear Magnetic Resonance (MAS-NMR) on a 20 MeV Kr irradiated ISG glass powder. A decrease of the silica network connectivity after irradiation with alpha particles and gold ions is deduced from the structural changes observations. NMR spectra revealed a partial conversion of BO 4 to BO 3 units but also a formation of AlO 5 and AlO 6 species after irradiation with Kr ions. The relationships between the mechanical and structural changes are also discussed. - Highlights: • Mechanical and structural properties of two borosilicate glass compositions irradiated with alpha particles and heavy ions were investigated. • Both kinds of particles induced a decrease of the hardness, reduced Young's modulus and density. • Electronic and nuclear interactions are responsible for the changes observed. • The evolution of the mechanical properties under irradiation is linked to the changes occured in the

  19. Interference between source-free radiation and radiation from sources: Particle-like behavior for classical radiation

    Science.gov (United States)

    Boyer, Timothy H.

    2017-09-01

    A simple junior-level electrodynamics problem is used to illustrate the interference between a source-free standing plane wave and a wave generated by a pulse in a current sheet. Depending upon the relative phases between the standing wave and the current pulse and also upon the relative magnitudes, we can find quite different patterns of emitted energy and momentum. If the source gives a large radiation pulse so that the source-free plane wave can be neglected, then the radiation spreads out symmetrically on either side of the current sheet. However, if the radiation sheet gives a pulse with fields comparable to those of the standing wave, then we can find a single radiation pulse moving to the right while the current sheet recoils to the left or the situation with the directions reversed. The example is a crude illustration of particle-like behavior arising from conventional classical electromagnetic behavior in the presence of source-free radiation. The discussion makes contact with the ideas of photons in modern physics.

  20. Particle cosmology

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The understanding of the Universe at the largest and smallest scales traditionally has been the subject of cosmology and particle physics, respectively. Studying the evolution of the Universe connects today's large scales with the tiny scales in the very early Universe and provides the link between the physics of particles and of the cosmos. This series of five lectures aims at a modern and critical presentation of the basic ideas, methods, models and observations in today's particle cosmology.

  1. Thermal annealing behavior of nano-size metal-oxide particles synthesized by ion implantation in Fe-Cr alloy

    Science.gov (United States)

    Zheng, C.; Gentils, A.; Ribis, J.; Borodin, V. A.; Descoins, M.; Mangelinck, D.; Dalle, F.; Arnal, B.; Delauche, L.

    2017-05-01

    Oxide dispersion strengthened (ODS) steels are promising structural materials for the next generation nuclear reactors, as well as fusion facilities. The detailed understanding of the mechanisms involved in the precipitation of nano-oxides during ODS steel production would strongly contribute to the improvement of the mechanical properties and the optimization of manufacturing of ODS steels, with a potentially strong economic impact for their industrialization. A useful tool for the experimental study of nano-oxide precipitation is ion implantation, a technique that is widely used to synthesize precipitate nanostructures in well-controlled conditions. Earlier, we have demonstrated the feasibility of synthesizing aluminum-oxide particles in the high purity Fe-10Cr alloy by consecutive implantation with Al and O ions at room temperature. This paper describes the effects of high-temperature annealing after the ion implantation stage on the development of the aluminum based oxide nanoparticle system. Using transmission electron microscopy and atom probe tomography experiments, we demonstrate that post-implantation heat treatment induces the growth of the nano-sized oxides in the implanted region and nucleation of new oxide precipitates behind the implantation zone as a result of the diffusion driven broadening of implant profiles. A tentative scenario for the development of metal-oxide nano-particles at both ion implantation and heat treatment stages is suggested based on the experimental observations.

  2. Failure Mechanical Behavior of Australian Strathbogie Granite at High Temperatures: Insights from Particle Flow Modeling

    Directory of Open Access Journals (Sweden)

    Sheng-Qi Yang

    2017-05-01

    Full Text Available Thermally induced damage has an important influence on rock mechanics and engineering, especially for high-level radioactive waste repositories, geological carbon storage, underground coal gasification, and hydrothermal systems. Additionally, the wide application of geothermal heat requires knowledge of the geothermal conditions of reservoir rocks at elevated temperature. However, few methods to date have been reported for investigating the micro-mechanics of specimens at elevated temperatures. Therefore, this paper uses a cluster model in particle flow code in two dimensions (PFC2D to simulate the uniaxial compressive testing of Australian Strathbogie granite at various elevated temperatures. The peak strength and ultimate failure mode of the granite specimens at different elevated temperatures obtained by the numerical methods are consistent with those obtained by experimentation. Since the tensile force is always concentrated around the boundary of the crystal, cracks easily occur at the intergranular contacts, especially between the b-b and b-k boundaries where less intragranular contact is observed. The intergranular and intragranular cracking of the specimens is almost constant with increasing temperature at low temperature, and then it rapidly and linearly increases. However, the inflection point of intergranular micro-cracking is less than that of intragranular cracking. Intergranular cracking is more easily induced by a high temperature than intragranular cracking. At an elevated temperature, the cumulative micro-crack counts curve propagates in a stable way during the active period, and it has no unstable crack propagation stage. The micro-cracks and parallel bond forces in the specimens with elevated temperature evolution and axial strain have different characteristics than those at lower temperature. More branch fractures and isolated wider micro-cracks are generated with increasing temperature when the temperature is over 400

  3. Effects of Quartz Particle Size and Sucrose Addition on Melting Behavior of a Melter Feed for High-Level Waste Glass

    International Nuclear Information System (INIS)

    Marcial, Jose; Hrma, Pavel R.; Schweiger, Michael J.; Swearingen, Kevin J.; Tegrotenhuis, Nathan E.; Henager, Samuel H.

    2010-01-01

    The behavior of melter feed (a mixture of nuclear waste and glass-forming additives) during waste-glass processing has a significant impact on the rate of the vitrification process. We studied the effects of silica particle size and sucrose addition on the volumetric expansion (foaming) of a high-alumina feed and the rate of dissolution of silica particles in feed samples heated at 5 C/min up to 1200 C. The initial size of quartz particles in feed ranged from 5 to 195 (micro)m. The fraction of the sucrose added ranged from 0 to 0.20 g per g glass. Extensive foaming occurred only in feeds with 5-(micro)m quartz particles; particles (ge) 150 (micro)m formed clusters. Particles of 5 (micro)m completely dissolved by 900 C whereas particles (ge) 150 (micro)m did not fully dissolve even when the temperature reached 1200 C. Sucrose addition had virtually zero impact on both foaming and the dissolution of silica particles.

  4. Effects of metallic Ti particles on the aging behavior and the influenced mechanical properties of squeeze-cast (SiCp+Ti)/7075Al hybrid composites

    International Nuclear Information System (INIS)

    Liu, Yixiong; Chen, Weiping; Yang, Chao; Zhu, Dezhi; Li, Yuanyuan

    2015-01-01

    The effects of metallic Ti particles on the aging behavior of squeeze-cast (SiC p +Ti)/7075Al hybrid composites and the mechanical properties of the aging treated composites were investigated. Results shown that the precipitation hardening of the hybrid composites during aging processes was delayed due to the segregation of solute Mg atoms in the vicinity of the Ti particles even though the activation energy of the η′ precipitates in the hybrid composites was reduced when compared with the Ti particle-free composites. The segregation of the solute Mg atoms was facilitated as a result of the high diffusivity paths formed by the generated dislocations in the matrix induced by the thermal misfit between the SiC particle and the matrix. The smaller activation energy for the hybrid composite may attribute to a significant reduction in the nucleation rate of the dislocation nucleated η′ precipitates compared with the Ti particle-free composite. After aging treated under the optimum aging conditions, the tensile strength of both composites was improved because of the precipitation hardening of the matrix alloy. In contrast with the reduced ductility of the traditional Ti particle-free composites after aging treatment, the ductility of the Ti particle-containing composites was improved as a result of the strengthened interfaces between the Ti particles and the matrix alloy

  5. Characterization, optical properties and laser ablation behavior of epoxy resin coatings reinforced with high reflectivity ceramic particles

    Science.gov (United States)

    Li, Wenzhi; Kong, Jing; Wu, Taotao; Gao, Lihong; Ma, Zhuang; Liu, Yanbo; Wang, Fuchi; Wei, Chenghua; Wang, Lijun

    2018-04-01

    Thermal damage induced by high power energy, especially high power laser, significantly affects the lifetime and performance of equipment. High-reflectance coating/film has attracted considerable attention due to its good performance in the damage protection. Preparing a high-reflectance coating with high reaction endothermal enthalpy will effectively consume a large amount of incident energy and in turn protect the substrate from thermal damage. In this study, a low temperature process was used to prepare coatings onto substrate with complex shape and avoid thermal effect during molding. An advanced high reflection ceramic powder, La1‑xSrxTiO3+δ , was added in the epoxy adhesive matrix to improve the reflectivity of coating. The optical properties and laser ablation behaviors of coatings with different ceramic additive ratio of La1‑xSrxTiO3+δ and modified epoxy-La1‑xSrxTiO3+δ with ammonium polyphosphate coatings were investigated, respectively. We found that the reflectivity of coatings is extremely high due to mixed high-reflection La1‑xSrxTiO3+δ particles, up to 96% at 1070 nm, which can significantly improve the laser resistance. In addition, the ammonium polyphosphate modifies the residual carbon structure of epoxy resin from discontinuous fine particles structure to continuous and porous structure, which greatly enhances the thermal-insulation property of coating. Furthermore, the laser ablation threshold is improved obviously, which is from 800 W cm‑2 to 1000 W cm‑2.

  6. Understanding selected trace elements behavior in a coal-fired power plant in Malaysia for assessment of abatement technologies.

    Science.gov (United States)

    Mokhtar, Mutahharah M; Taib, Rozainee M; Hassim, Mimi H

    2014-08-01

    The Proposed New Environmental Quality (Clean Air) Regulation 201X (Draft), which replaces the Malaysia Environmental Quality (Clean Air) 1978, specifies limits to additional pollutants from power generation using fossil fuel. The new pollutants include Hg, HCl, and HF with limits of 0.03, 100, and 15 mg/N-m3 at 6% O2, respectively. These pollutants are normally present in very small concentrations (known as trace elements [TEs]), and hence are often neglected in environmental air quality monitoring in Malaysia. Following the enactment of the new regulation, it is now imperative to understand the TEs behavior and to assess the capability of the existing abatement technologies to comply with the new emission limits. This paper presents the comparison of TEs behavior of the most volatile (Hg, Cl, F) and less volatile (As, Be, Cd, Cr, Ni, Se, Pb) elements in subbituminous and bituminous coal and coal combustion products (CCP) (i.e., fly ash and bottom ash) from separate firing of subbituminous and bituminous coal in a coal-fired power plant in Malaysia. The effect of air pollution control devices configuration in removal of TEs was also investigated to evaluate the effectiveness of abatement technologies used in the plant. This study showed that subbituminous and bituminous coals and their CCPs have different TEs behavior. It is speculated that ash content could be a factor for such diverse behavior In addition, the type of coal and the concentrations of TEs in feed coal were to some extent influenced by the emission of TEs in flue gas. The electrostatic precipitator (ESP) and seawater flue gas desulfurization (FGD) used in the studied coal-fired power plant were found effective in removing TEs in particulate and vapor form, respectively, as well as complying with the new specified emission limits. Implications: Coals used by power plants in Peninsular Malaysia come from the same supplier (Tenaga Nasional Berhad Fuel Services), which is a subsidiary of the Malaysia

  7. Understanding the molecular behavior of organotin compounds to design their effective use as agrochemicals: exploration via quantum chemistry and experiments.

    Science.gov (United States)

    Ramalho, Teodorico C; Rocha, Marcus V J; da Cunha, Elaine F F; Oliveira, Luiz C A; Carvalho, Kele T C

    2010-10-01

    The high frequency of contamination by herbicides suggests the need for more active and selective agrochemicals. Organotin compounds are the active component of some herbicides, such as Du-Ter and Brestan, which is also a potent inhibitor of the F1Fo ATP Synthase. That is a key enzyme, because the ATP production is one of the major chemical reactions in living organisms. Thus ATP Synthase is regarded as a prime target for organotin compounds. In this line, molecular modeling studies and DFT calculations were performed in order to understand the molecular behavior of those compounds in solution. In addition, we investigated the reaction mechanism by ESI-MS analyses of the diphenyltin dichloride. Our findings indicate that an unstable key-intermediate generated in situ might take place in the reaction with ATP Synthase.

  8. Using Self-Determination Theory to Understand Motivation Deficits in Schizophrenia: The ‘Why’ of Motivated Behavior

    Science.gov (United States)

    Gard, David E.; Sanchez, Amy H.; Starr, Jessica; Cooper, Shanna; Fisher, Melissa; Rowlands, Abby; Vinogradov, Sophia

    2014-01-01

    Self-Determination Theory (SDT) provides a model for understanding motivation deficits in schizophrenia, and recent research has focused on problems with intrinsic motivation. However, SDT emphasizes that motivated behavior results from three different factors: intrinsic motivators (facilitated by needs for autonomy, competency, and relatedness), extrinsic motivators (towards reward or away from punishment), or when intrinsic and extrinsic motivators are absent or thwarted a disconnect/disengagement occurs resulting in behavior driven by boredom or ‘passing time’. Using a novel approach to Ecological Momentary Assessment, we assessed the degree to which people with schizophrenia were motivated by these factors relative to healthy control participants. Forty-seven people with and 41 people without schizophrenia were provided with cell phones and were called four times a day for one week. On each call participants were asked about their goals, and about the most important reason motivating each goal. All responses were coded by independent raters (blind to group and hypotheses) on all SDT motivating factors, and ratings were correlated to patient functioning and symptoms. We found that, relative to healthy participants, people with schizophrenia reported goals that were: 1) less motivated by filling autonomy and competency needs, but equivalently motivated by relatedness; 2) less extrinsically rewarding, but equivalently motivated by punishment; 3) more disconnected/disengaged. Higher disconnected/disengaged goals were significantly associated with higher negative symptoms and lower functioning. These findings indicate several important leverage points for behavioral treatments and suggest the need for vigorous psychosocial intervention focusing on autonomy, competence, and reward early in the course of illness. PMID:24853060

  9. The paths of mortality: how understanding the biology of aging can help explain systems behavior of single cells.

    Science.gov (United States)

    Crane, Matthew M; Kaeberlein, Matt

    2018-04-01

    Aging is a fundamental aspect of life, yet also one of the most confounding. In individual cells, aging results in a progressive decline which affects all organelles and reduces a cell's ability to maintain homeostasis. Because of the interconnected nature of cellular systems, the failure of even a single organelle can have cascading effects. We are just beginning to understand the dramatic physiological changes that occur during aging. Because most aging research has focused on population dynamics, or differences between wild-type and mutant populations, single-cell behavior has been largely overlooked. An open question is whether aging cells are defined by predictable sequences of physiological changes, or whether they proceed along divergent aging trajectories defined by whichever system begins to fail first. Can aging be best characterized by a cell-cycle like model with stereotyped states all cells progress through, or a Waddington landscape with divergent trajectories? Here we present work on understanding the changing physiological states of aging cells, why it will impact systems and synthetic biologists, and how the systems community can contribute significantly to the study of aging.

  10. Thermally sensitive block copolymer particles prepared via aerosol flow reactor method: Morphological characterization and behavior in water

    OpenAIRE

    Nykänen, Antti; Rahikkala, Antti; Hirvonen, Sami-Pekka; Aseyev, Vladimir; Tenhu, Heikki; Mezzenga, Raffaele; Raula, Janne; Kauppinen, Esko; Ruokolainen, Janne

    2012-01-01

    This work describes properties of thermo-sensitive submicron sized particles having the same chemical composition but different morphologies. These particles have been prepared with an aerosol technique using dimethylformamide solutions of linear polystyrene-block-poly(N-isopropylacrylamide-block-polystyrene, PS-b-PNIPAM-b-PS. The particles were characterized by cryo-electron microscopy, microcalorimetry, and light scattering. Block-copolymers self-assembled within the particles forming onion...

  11. Effects of Initial Powder Compact Thickness, Lubrication, and Particle Morphology on the Cold Compaction Behavior of Ti Powder

    Science.gov (United States)

    Lou, Jia; Gabbitas, Brian; Zhang, Deliang; Yang, Fei

    2015-08-01

    This work investigates the compaction behavior of hydride-dehydride CP-Ti powder from green density/compaction pressure curves. These were obtained through a modification of selected processing conditions, such as variation in compact thickness, the use of internal lubrication, and additions of plasma rotating electrode process powder. A modified Cooper-Eaton equation, which treats the compaction process to be a combination of particle rearrangement (PR) and plastic deformation (PD) mechanisms, was used to simulate the curves. A comparison with aluminum and iron compaction is also carried out in this study. The research indicated that the cold compaction of titanium powder can be separated into two stages: a PR stage (stage I), which occurs at a compacting pressure in the range of 0 to 200 MPa, followed by a further PR stage initiated by PD, when the compaction pressure is in the range of 200 to 1000 MPa. The existence of stage II is due to the low plastic deformability of titanium and low density achieved at the end of stage I.

  12. Thermal and magnetic behavior of Angustifolia Kunth bamboo fibers covered with Fe{sub 3}O{sub 4} particles

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, S. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Arias, N.P. [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Departamento de Ingenieria Electrica, Electronica y Computacion, Facultad de Ingenieria y Arquitectura, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Giraldo, O., E-mail: ohggiraldo@hotmail.com [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Rosales-Rivera, A.; Moscoso, O. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia)

    2012-08-15

    Several Angustifolia Kunth bamboo fibers, which have been previously treated with an alkaline solution, were coated with magnetite particles. The coating of the fibers was achieved by an in-situ co-precipitation method with Fe{sup 2+} and Fe{sup 3+}in NaOH or NH{sub 4}OH. The fibers were evaluated by chemical analysis using atomic absorption (A.A.) technique, structural characterization by X-ray diffraction (XRD), thermal stability with thermo-gravimetric analysis (TGA) in nitrogen at temperature range between 23 Degree-Sign C and 800 Degree-Sign C and magnetic behavior using vibrating sample magnetometry (VSM) applying a magnetic field between -27 KOe and 27 KOe at room temperature. We found that the thermal stability and magnetization depend of the synthesis method used to cover the Angustifolia Kunth bamboo fibers. In addition, an improved magnetic response was observed when NaOH solution is used to generate the magnetite coating on the fiber surface.

  13. Deposition behavior of polystyrene latex particles on solid surfaces during migration through an artificial fracture in a granite rock sample

    International Nuclear Information System (INIS)

    Chinju, Hirofumi; Tanaka, Satoru; Kuno, Yoshio

    2001-01-01

    The deposition behavior of colloids during transport through heterogeneous media was observed by conducting column experiments to study migration of polystyrene latex particles (diameter=309 nm) through columns packed with artificially fractured granite rock (length=300 and 150 mm). The experiments were conducted under conditions of different ionic strengths and flow rates. The results were similar to those for colloid deposition in columns packed with glass beads reported previously; the colloid breakthrough curves showed three stages, characterized by different rates of change in the concentration of effluent. Colloid deposition on the fracture surfaces was described by considering strong and weak deposition sites. Scanning Electron Microscopy (SEM) observations indicated the existence of strong and weak sites on the fracture surfaces regardless of mineral composition. The observations also showed that the strong deposition sites tended to exist on surface irregularities such as cracks or protrusions. The degree of colloid deposition increased with increasing ionic strength and decreasing flow rate. The dependencies on ionic strength and flow rate agreed qualitatively with the DLVO theory and the previous experimental results, respectively. (author)

  14. Study of particle swarm optimization particle trajectories

    CSIR Research Space (South Africa)

    Van den Bergh, F

    2006-01-01

    Full Text Available Particle swarm optimization (PSO) has shown to be an efficient, robust and simple optimization algorithm. Most of the PSO studies are empirical, with only a few theoretical analyses that concentrate on understanding particle trajectories...

  15. Fatigue behavior in water of Y-TZP zirconia ceramics after abrasion with 30 µm silica-coated alumina particles

    Science.gov (United States)

    Scherrer, Susanne S.; Cattani-Lorente, Maria; Vittecoq, Eric; de Mestral, François; Griggs, Jason A.; Wiskott, H.W. Anselm

    2011-01-01

    significantly different (p < 0.001) for all sandblasted groups vs. the “as received” except for Zeno (Wieland) (p = 0.295). Failures started from both intrinsic and machined flaws. Significance 30 µm particle sandblasting did significantly improve the fatigue behavior of three out of four Y-TZP ceramic materials and can therefore be recommended for adhesive cementation procedures. This study was supported in part by grants from the Swiss Society for Reconstructive Dentistry (SSRD) and 3M Espe. PMID:21056462

  16. Particle physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  17. Cognitive and affective components of mental workload: Understanding the effects of each on human decision making behavior

    Science.gov (United States)

    Nygren, Thomas E.

    1992-01-01

    Human factors and ergonomics researchers have recognized for some time the increasing importance of understanding the role of the construct of mental workload in flight research. Current models of mental workload suggest that it is a multidimensional and complex construct, but one that has proved difficult to measure. Because of this difficulty, emphasis has usually been placed on using direct reports through subjective measures such as rating scales to assess levels of mental workload. The NASA Task Load Index (NASA/TLX, Hart and Staveland) has been shown to be a highly reliable and sensitive measure of perceived mental workload. But a problem with measures like TLX is that there is still considerable disagreement as to what it is about mental workload that these subjective measures are actually measuring. The empirical use of subjective workload measures has largely been to provide estimates of the cognitive components of the actual mental workload required for a task. However, my research suggests that these measures may, in fact have greater potential in accurately assessing the affective components of workload. That is, for example, TLX may be more likely to assess the positive and negative feelings associated with varying workload levels, which in turn may potentially influence the decision making behavior that directly bears on performance and safety issues. Pilots, for example, are often called upon to complete many complex tasks that are high in mental workload, stress, and frustration, and that have significant dynamic decision making components -- often ones that involve risk as well.

  18. Preparing for smart grid technologies: A behavioral decision research approach to understanding consumer expectations about smart meters

    International Nuclear Information System (INIS)

    Krishnamurti, Tamar; Schwartz, Daniel; Davis, Alexander; Fischhoff, Baruch; Bruine de Bruin, Wändi; Lave, Lester; Wang, Jack

    2012-01-01

    With the enactment of the 2009 American Recovery and Reinvestment Act, U.S. President Obama made a public commitment to a new approach to energy production and transmission in the United States. It features installing smart meters and related technologies in residential homes, as part of transforming the current electrical grid into a “smart grid.” Realizing this transformation requires consumers to accept these new technologies and take advantage of the opportunities that they create. We use methods from behavioral decision research to understand consumer beliefs about smart meters, including in-depth mental models interviews and a follow-up survey with a sample of potential smart meter customers of a major U.S. mid-Atlantic electricity utility. In both the surveys and the interviews, most respondents reported wanting smart meters. However, these preferences were often based on erroneous beliefs regarding their purpose and function. Respondents confused smart meters with in-home displays and other enabling technologies, while expecting to realize immediate savings. They also perceived risks, including less control over their electricity usage, violations of their privacy, and increased costs. We discuss the policy implications of our results. - Highlights: ► We outline normative risks and benefits of smart meters from scientific literature. ► We examine consumer perceptions of smart meters via interviews and surveys. ► Smart meter desire stems from consumer misconceptions about purpose and function. ► Appropriate communications may prevent consumer protests against the smart grid.

  19. Analytical solution of settling behavior of a particle in incompressible Newtonian fluid by using Parameterized Perturbation Method

    OpenAIRE

    Reza Mohammadyari; Mazaher Rahimi Esboee; Majid Rahgoshay

    2015-01-01

    The problem of solid particle settling is a well known problem in mechanic of fluids. The parametrized Perturbation Method is applied to analytically solve the unsteady motion of a spherical particle falling in a Newtonian fluid using the drag of the form given by Oseen/Ferreira, for a range of Reynolds numbers. Particle equation of motion involved added mass term and ignored the Basset term. By using this new kind of perturbation method called parameterized perturbation method (PPM), analyti...

  20. Understanding HIV transmission risk behavior among HIV-infected South Africans receiving antiretroviral therapy: an information--motivation--behavioral skills model analysis.

    Science.gov (United States)

    Kiene, Susan M; Fisher, William A; Shuper, Paul A; Cornman, Deborah H; Christie, Sarah; Macdonald, Susan; Pillay, Sandy; Mahlase, Gethwana; Fisher, Jeffrey D

    2013-08-01

    The current study applied the Information-Motivation-Behavioral Skills (IMB) model (Fisher & Fisher, 1992; Fisher & Fisher, 1993) to identify factors associated with human immunodeficiency virus (HIV) transmission risk behavior among HIV-infected South Africans receiving antiretroviral therapy (ART), a population of considerable significance for curtailing, or maintaining, South Africa's generalized HIV epidemic. HIV prevention information, HIV prevention motivation, HIV prevention behavioral skills, and HIV transmission risk behavior were assessed in a sample of 1,388 South Africans infected with HIV and receiving ART in 16 clinics in KwaZulu-Natal, South Africa. Findings confirmed the assumptions of the IMB model and demonstrated that HIV prevention information and HIV prevention motivation work through HIV prevention behavioral skills to affect HIV transmission risk behavior in this population. Subanalyses confirmed these relationships for HIV transmission risk behavior overall and for HIV transmission risk behavior with partners perceived to be HIV-negative or HIV-status unknown. A consistent pattern of gender differences showed that for men, HIV prevention information and HIV prevention motivation may have direct links with HIV preventive behavior, whereas for women, the effect of HIV prevention motivation works through HIV prevention behavioral skills to affect HIV preventive behavior. These IMB model-based findings suggest directions for HIV prevention interventions with South African men and women living with HIV and on ART as an important component of overall strategies to contain South Africa's generalized HIV epidemic. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  1. Agglomeration Behavior of Non-Metallic Particles on the Surface of Ca-Treated High-Carbon Liquid Steel: An In Situ Investigation

    Directory of Open Access Journals (Sweden)

    Yasuhiro Tanaka

    2018-03-01

    Full Text Available The agglomeration behavior of non-metallic inclusion is a critical phenomenon that needs to be controlled as it has a direct relationship with the performance of produced steel. Although the agglomerates can be potential points for serious defects in every grade of steel, they are likely to be more serious in high-carbon steel due to the low ductility of these grades of steels as well as their usage in severe conditions. Confocal scanning laser microscopes (CSLM have been used by different researchers to investigate the agglomeration behavior of non-metallic particles at the interface of liquid steel and Ar gas, in situ. In recent decades, the agglomeration of Al2O3 particle in and on the surface of low-carbon steel has been widely investigated. However, there are very few studies focussing on non-Al2O3 inclusions which are included in a Ca-treated high-carbon steel. In this study, the agglomeration behaviors of sulfide/sulfide and sulfide/oxide particles on the surface of liquid high-carbon steel have been investigated in detail using CSLM. Agglomerations on the liquid surface are governed by capillary forces similar to the Al2O3 particle but this study demonstrates that agglomeration forces among non-Al2O3 particles on the surface of re-melted high-carbon samples are lower than pure-Al2O3 on the surface of low-carbon steel. Despite this, they show similar or longer acting lengths than pure-Al2O3.

  2. Applying the Skill-Rule-Knowledge Framework to Understanding Operators’ Behaviors and Workload in Advanced Main Control Rooms

    International Nuclear Information System (INIS)

    Lin, Chiuhsiang Joe; Shiang, Wei-Jung; Chuang, Chun-Yu; Liou, Jin-Liang

    2014-01-01

    Highlights: • Operator behaviors were analyzed according to Rasmussen's SRK classification. • Different job positions connote different abilities to perform the job successfully. • Rule-based behavior comprised the main behavior patterns of the operating crew. - Abstract: For the past years, a number of researches have focused on operators’ behaviors and workloads in advanced main control rooms (MCRs) in either the procedure-domain or knowledge-domain and in either workload-increased or workload-decreased conditions. Different job positions connote different responsibilities and abilities that are required to perform the job successfully. However, it may be inappropriate to apply a dichotomy in these issues. In this study, we clarified these controversial points through the analysis of the time, frequency, and workload of the behaviors based on Rasmussen's skill–rule–knowledge classification (SRK framework) according to the supervisor operator (SRO), reactor operator (RO), and assistant reactor operator (ARO). The results showed that, for the SRO, rule- and knowledge-based behaviors occurred more often than skill-based behavior in terms of time and frequency, and knowledge-based behavior was the main source of workload. For the RO, no significant differences were found among the three behavior types in terms of frequency and workload, but more time was spent on rule-based behaviors than on skill- and knowledge-based behaviors. The ARO spent more time performing skill-based behaviors than rule- and knowledge-based behaviors, but in terms of frequency and workload, rule-based behavior was the predominant type. Operators’ behaviors contribute to a plant's defense-in-depth approach to safety and serve a vital function in ensuring its safe operation. Research on behavioral taxonomies of advanced MCRs has many significant benefits in both scientific-theoretical and applied practical fields

  3. Effect of particle morphology of Ni on the mechanical behavior of AZ91E-Ni coated nano Al2O3 composites

    Science.gov (United States)

    Sameer Kumar, D.; Suman, K. N. S.; Poddar, Palash

    2017-06-01

    The properties of any composite always depend on the bonding between the matrix and reinforcement phases. One way of improving the wettability of reinforcement in a matrix is to apply a layer of coating on reinforcing particles. The present study aims at developing Ni coating on nano Al2O3 ceramic particles and dispersing them in AZ91E magnesium matrix material. The electroless plating method has been employed to coat the particles and semi solid stir casting technique was adopted to prepare the composites. Several weight fractions of dispersed phase are considered to analyze the behavior of the fabricated composites. Field emission scanning electron microscopy (FESEM) and x-ray diffraction analysis has been carried out to investigate the distribution of particles and phase characteristics of the proposed material. The physical and mechanical behavior of the material was examined through density measurements, hardness, elastic modulus, ductility and tensile strength calculations. The metal coating on reinforcement aids to promote metal-metal bonding interface reactions which result in improved properties of the composite. Tensile fractography was carried out under FESEM and presented.

  4. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 μm were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the

  5. Understanding the Impact of Childhood Sexual Abuse on Men's Risk Behavior: Protocol for a Mixed-Methods Study.

    Science.gov (United States)

    Downing, Martin J; Brown, Dominique; Steen, Jeffrey; Benoit, Ellen

    2018-02-26

    Childhood sexual abuse (CSA) remains a critical public health issue among black and Latino men who have sex with men (MSM), as it is associated with multiple negative outcomes including substance misuse, poor mental health, revictimization, and high-risk sexual behavior. Most CSA research with MSM relies on quantitative assessment that often precludes consideration of cultural variations in how formative sexual experiences are understood and is based on inconsistent or overly restrictive definitions of abuse, and therefore may fail to detect certain abusive experiences (eg, those involving female perpetrators), which can have harmful health consequences if they remain unrecognized. The objective of this study is to overcome existing limitations in the literature by drawing on perspectives of black and Latino MSM and men who have sex with men and women (MSMW), as well as relevant service providers to better understand the role of, and the need to include, sexual abuse histories (eg, CSA) in treatment and counseling settings, with the long-term goal of improving assessment and health outcomes. We will conduct mixed-methods interviews, framed by an intersectionality approach, with 80 black and Latino men (40 MSM and 40 MSMW) in New York City (NYC), exploring appraisals of their formative sexual experiences, including those described as consensual but meeting criteria for CSA. We will also interview 30 local service providers representing substance abuse treatment, mental health care, and HIV prevention and outreach. The study was launched in May 2017. This formative research will inform testable approaches to assessing and incorporating sexual abuse history into substance abuse treatment and other health and mental health services used by men with such histories. ©Martin J Downing Jr, Dominique Brown, Jeffrey Steen, Ellen Benoit. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 26.02.2018.

  6. Neurodevelopmental consequences of pediatric cancer and its treatment: applying an early adversity framework to understanding cognitive, behavioral, and emotional outcomes.

    Science.gov (United States)

    Marusak, Hilary A; Iadipaolo, Allesandra S; Harper, Felicity W; Elrahal, Farrah; Taub, Jeffrey W; Goldberg, Elimelech; Rabinak, Christine A

    2017-12-22

    Today, children are surviving pediatric cancer at unprecedented rates, making it one of modern medicine's true success stories. However, we are increasingly becoming aware of several deleterious effects of cancer and the subsequent "cure" that extend beyond physical sequelae. Indeed, survivors of childhood cancer commonly report cognitive, emotional, and psychological difficulties, including attentional difficulties, anxiety, and posttraumatic stress symptoms (PTSS). Cognitive late- and long-term effects have been largely attributed to neurotoxic effects of cancer treatments (e.g., chemotherapy, cranial irradiation, surgery) on brain development. The role of childhood adversity in pediatric cancer - namely, the presence of a life-threatening disease and endurance of invasive medical procedures - has been largely ignored in the existing neuroscientific literature, despite compelling research by our group and others showing that exposure to more commonly studied adverse childhood experiences (i.e., domestic and community violence, physical, sexual, and emotional abuse) strongly imprints on neural development. While these adverse childhood experiences are different in many ways from the experience of childhood cancer (e.g., context, nature, source), they do share a common element of exposure to threat (i.e., threat to life or physical integrity). Therefore, we argue that the double hit of early threat and cancer treatments likely alters neural development, and ultimately, cognitive, behavioral, and emotional outcomes. In this paper, we (1) review the existing neuroimaging research on child, adolescent, and adult survivors of childhood cancer, (2) summarize gaps in our current understanding, (3) propose a novel neurobiological framework that characterizes childhood cancer as a type of childhood adversity, particularly a form of early threat, focusing on development of the hippocampus and the salience and emotion network (SEN), and (4) outline future directions for

  7. Tensile properties and fracture behavior of laser cladded WC/Ni composite coatings with different contents of WC particle studied by in-situ tensile testing

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jin-Sha [Key Laboratory of Pressure Systems and Safety, Ministry of Education, East China University of Science and Technology, 130 Meilong Road, Xuhui District, Shanghai 200237 (China); Zhang, Xian-Cheng, E-mail: xczhang@ecust.edu.cn [Key Laboratory of Pressure Systems and Safety, Ministry of Education, East China University of Science and Technology, 130 Meilong Road, Xuhui District, Shanghai 200237 (China); Xuan, Fu-Zhen; Tian, Fu-Qiang; Wang, Zheng-Dong; Tu, Shan-Tung [Key Laboratory of Pressure Systems and Safety, Ministry of Education, East China University of Science and Technology, 130 Meilong Road, Xuhui District, Shanghai 200237 (China)

    2013-01-10

    The aim of this paper was to address the effect of WC content on the tensile properties of WC/Ni composite coatings deposited by laser cladding on 45 steel substrates. The tensile tests were performed in the chamber of a scanning electron microscope. Experimental results showed that the mechanical properties and fracture behavior of WC/Ni coatings were strongly dependent on the volume fraction of WC reinforcing particles in the coatings. The tensile properties of the coating decreased with increasing content of WC particle. When the WC content was relatively high, multiple through-width cracks (TWC) in the coating can be found. The number of through-width cracks in the coating as a function of applied strain was measured. From the in-situ observation of coating surfaces, most of cracks were initiated from the WC particle, and then propagated throughout the coatings. This phenomenon was attributed to the stress concentration in the WC particle or near the WC particle, which was confirmed by using finite element analysis. The present research may provide some insights on the development of designing methodology of composite coatings.

  8. Alloying Behavior and Properties of Al-Based Composites Reinforced with Al85Fe15 Metallic Glass Particles Fabricated by Mechanical Alloying and Hot Pressing Consolidation

    Science.gov (United States)

    Zhang, Lanxiang; Yang, LiKun; Leng, Jinfeng; Wang, Tongyang; Wang, Yan

    2017-04-01

    In this study, Al85Fe15 metallic glass particles with high onset crystallization temperature (1209 K) were synthesized by a mechanical alloying method. High-quality 6061Al-based composites reinforced with Al85Fe15 metallic glass particles were fabricated by a vacuum hot-pressing sintering technique. The glass particles with flake-like shape are distributed uniformly in the Al matrix. The bulk composites possess high relative density, excellent hardness and strength. The microhardness values of the Al-based bulk composites with the additions of 20 vol.% and 30 vol.% Al85Fe15 particles are 204 MPa and 248 MPa, respectively, which are much higher than that of 6061Al (61 MPa). The compressive yield strength of the 30 vol.% glass-reinforced composite is 478 MPa, which is enhanced by 273% compared with 6061Al. The amorphous characteristic and homogeneous dispersion of glass particles account for the excellent mechanical properties of the Al-based composites. In addition, the corrosion behavior of Al-based composites in a seawater solution has been investigated by electrochemical polarization measurements. Compared to 6061Al, the 30 vol.% glass-reinforced composite shows the lower corrosion/passive current density and larger passive region, indicating the greatly enhanced corrosion resistance.

  9. Vertical pneumatic conveying in dilute and dense-phase flows: experimental study of the influence of particle density and diameter on fluid dynamic behavior

    Directory of Open Access Journals (Sweden)

    Narimatsu C.P.

    2001-01-01

    Full Text Available In this work, the effects of particle size and density on the fluid dynamic behavior of vertical gas-solid transport of Group D particles in a 53.4 mm diameter transport tube were studied. For the conditions tested, the experimental curves of pressure gradient versus air velocity presented a minimum pressure gradient point, which is associated with a change in the flow regime from dense to dilute phase. The increases in particle size from 1.00 to 3.68 mm and in density from 935 to 2500 kg/m³ caused an increase in pressure gradient for the dense-phase transport region, but were not relevant in dilute transport. The transition velocity between dense and dilute flow (Umin also increased with increasing particle density and diameter. An empirical equation was fitted for predicting transition air velocity for the transport of glass spheres. Additional experiments, covering a wider range of conditions and particles properties, are still needed to allow the fitting of a generalized equation for prediction of Umin.

  10. Measuring laves phase particle size and thermodynamic calculating its growth and coarsening behavior in P92 steels

    DEFF Research Database (Denmark)

    Yao, Bing-Yin; Zhou, Rong-Can; Fan, Chang-Xin

    2010-01-01

    The growth of Laves phase particles in three kinds of P92 steels were investigated. Laves phase particles can be easily separated and distinguished from the matrix and other particles by atom number contrast using comparisons of the backscatter electrons (BSE) images and the secondary electrons (...... attained between measurements in SEM and modeling by DICTRA. Ostwald ripening should be used for the coarsening calculation of Laves phase in P92 steels for time longer than 20000 h and 50000 h at 650°C and 600°C, respectively. © 2010 Chin. Soc. for Elec. Eng....

  11. Sex Differences in Affect Behaviors, Desired Social Responses, and Accuracy at Understanding the Social Desires of Other People

    OpenAIRE

    Jacob M. Vigil

    2008-01-01

    I recently proposed a socio-relational framework that suggests that phenotypic variation in the expression of discrete affect behaviors (e.g., expressed anger vs. sadness) may reflect two basic dimensions of behavioral response. The first dimension is the motivation to selectively attract or avoid interactions with different people. The second dimension is the behavioral display of either personal capacity or trustworthiness cues, often through the expression of dominant and submissive behavi...

  12. Analytical solution of settling behavior of a particle in incompressible Newtonian fluid by using Parameterized Perturbation Method

    Directory of Open Access Journals (Sweden)

    Reza Mohammadyari

    2015-08-01

    Full Text Available The problem of solid particle settling is a well known problem in mechanic of fluids. The parametrized Perturbation Method is applied to analytically solve the unsteady motion of a spherical particle falling in a Newtonian fluid using the drag of the form given by Oseen/Ferreira, for a range of Reynolds numbers. Particle equation of motion involved added mass term and ignored the Basset term. By using this new kind of perturbation method called parameterized perturbation method (PPM, analytical expressions for the instantaneous velocity, acceleration and position of the particle were derived. The presented results show the effectiveness of PPM and high rate of convergency of the method to achieve acceptable answers.

  13. Particle-Scale Studies of the Influence of the Properties of the Matrix of a Debris Flow on its Erosional Behavior

    Science.gov (United States)

    Hill, K. M.; Mullenbach, J.; Ghasemi, A.; Feng, Q.; Fritton, P.

    2017-12-01

    Debris flows - massive flows of fluid and particles - create significant hazard for communities established in or near mountainous regions. Recent field and laboratory observations have indicated that the nature of the matrix of rocky debris flows - the muddy or watery interstitial fluid among the gravel and boulders - can have a significant influence on the flow behaviors of a debris flow, from local sorting behaviors to entrainment and depositional behaviors. In this presentation, we report on our experimental investigations of the influence of the rheology and relative density of the matrix of a debris flow on its behaviors using laboratory experiments of particle-fluid flows and their erosive behaviors. To do so, we perform laboratory experiments of erosive debris flows where we systematically vary the interstitial fluid in our debris flow and the erodible bed over which it flows. We track the particles throughout the experiment along with pore fluid pressure which enables us to determine the instantaneous flow dynamics and correlations in the flow and erosion behavior. We find that entrainment rate varies substantially with interstitial fluid viscosity, essentially increasing with decreasing interstitial fluid viscosity, yet this relationship is not strictly monotonic and varies in time. We use these variations as a basis to investigate four specific mechanisms previously suggested responsible for entrainment by debris flows: (1) bed shear stress, (2) granular temperature (essentially, correlated velocity fluctuations), (3) pore fluid pressures, and (4) excess pore fluid pressure (measured pore pressure that exceeds that associated with the weight of the interstitial fluid). We find that both average and instantaneous bed shear stresses and granular temperatures are poorly correlated with associated entrainment rates. Rather, the excess pore pressure is well correlated with entrainment rates, particularly under conditions when the entrainment rate is the

  14. Survey report on awareness and participation behavior in disabled sports and disability understanding after Tokyo’s bid for the 2020 Olympics and Paralympics

    Science.gov (United States)

    Shiota, Kotomi

    2018-01-01

    [Purpose] This study analyzes awareness and participation behavior in disabled sports and disability understanding after Tokyo’s bid for the 2020 Olympics and Paralympics. [Subjects and Methods] The study conducted a cross survey on 220 registrants of an Internet research firm. It analyzed: the awareness of citizens and their behavioral changes, in the aftermath of the allocation of Olympic and Paralympic Games; subject attributes and education level; recognition of disabled sports; and the awareness and behavior of participants, with regard to disabled sports. The analysis was conducted using SPSS Ver. 21 (IBM). [Results] The subjects were not interested in watching (72.2%), participating (76.8%), or volunteering (71.8%) in disabled sports. In addition, 76.8% of the subjects exhibited no behavioral changes—such as by watching, participating, or volunteering in disabled sports—after the Olympics and Paralympics bid decision. [Conclusion] This study’s subjects had no confidence in their disability knowledge and no opportunities to interact with disabled persons. Furthermore, the bids for mega-events such as the Olympic and Paralympic Games did not lead to behavioral changes concerning disabled sports. Therefore, disability understanding should promote and deepen participation behavior in disabled sports. PMID:29410556

  15. Evaluation of the Safety Detective Program: A Classroom-Based Intervention to Increase Kindergarten Children's Understanding of Home Safety Hazards and Injury-Risk Behaviors to Avoid.

    Science.gov (United States)

    Morrongiello, Barbara A; Bell, Melissa; Park, Katey; Pogrebtsova, Katya

    2016-01-01

    Home injuries are a leading cause of mortality and morbidity for young children. Most programs that aim to improve their knowledge of home safety have been narrowly focused on one injury type and/or required specialized personnel for delivery. The purpose of the current study was to evaluate the effectiveness of a new Safety Detective Program that was designed to teach young children (4-6 years) about several types of home safety hazards and unsafe behaviors, with the program delivered in a classroom setting by non-experts based on manualized training. The current study used a randomized group, pre-post design to evaluate the effectiveness of the program to increase children's knowledge and understanding of home safety hazards and injury-risk behaviors to avoid. Children participated in six structured sessions, covering burns, falls, drowning, and poisoning. Each session involved play-based activities (storybook, song, and game or craft) to teach main messages about hazards and injury-risk behaviors, a take home activity, and a parent information sheet about the injury type covered that day. An individually administered photo-sort task with follow-up interview was used to measure intervention and control group participants' knowledge and understanding of injury-risk behaviors before and after program delivery. Children in the intervention, but not the control, group exhibited significant gains in their knowledge and understanding of home safety hazards and injury-risk behaviors to avoid, establishing the effectiveness of the program. This evaluation indicates that the Safety Detective Program can be delivered in classrooms without requiring specialized personnel or extensive training and with positive changes obtained. The program holds much promise as a means of improving kindergarten children's understanding of a broad range of home hazards and injury-risk behaviors that are relevant to their safety.

  16. The action suited to the word? Use of the framework of risk information seeking to understand risk-related behaviors.

    NARCIS (Netherlands)

    Kievik, Milou; ter Huurne, E.F.J.; Gutteling, Jan M.

    2012-01-01

    Although a growing body of risk communication research focuses on how people process risk information, one question that is overlooked is how the seeking of information contributes to behavioral adaptation toward the risk issue. How are people’s behavioral responses to risks affected by the search

  17. Brief Report: Understanding Crisis Behaviors in Hospitalized Psychiatric Patients with Autism Spectrum Disorder--Iceberg Assessment Interview

    Science.gov (United States)

    Stark, Kate H.; Barnes, Julia C.; Young, Nicholas D.; Gabriels, Robin L.

    2015-01-01

    Children and adolescents with autism spectrum disorder (ASD) are at risk for emotional dysregulation and behavior problems that can escalate to levels requiring psychiatric hospitalization. Evaluating the etiology of such behaviors can be challenging for health care providers, as individuals with ASD can have difficulty self-reporting concerns.…

  18. Modulating mimicry: Exploring the roles of inhibitory control and social understanding in 5-year-olds' behavioral mimicry

    NARCIS (Netherlands)

    Schaik, J.E. van; Hunnius, S.

    2018-01-01

    During adult interactions, behavioral mimicry, the implicit copying of an interaction partner's postures and mannerisms, communicates liking and affiliation. While this social behavior likely develops during early childhood, it is unclear which factors contribute to its emergence. Here, the roles of

  19. Parental mind-mindedness but not false belief understanding predicts Hong Kong children's lie-telling behavior in a temptation resistance task.

    Science.gov (United States)

    Wang, Lamei; Zhu, Liqi; Wang, Zhenlin

    2017-10-01

    Children can tell lies before they understand the concept of false belief. This study investigated the relationship between parental mind-mindedness, defined as the propensity of parents to view their children as mental agents with independent thoughts and feelings, and the lie-telling behavior of Hong Kong children aged 3-6years. The results confirmed earlier findings indicating that Hong Kong children's understanding of false belief is delayed; nevertheless, the participants appeared to lie just as well as children from other cultures. The lie-telling behavior of Hong Kong children was predicted by parental mind-mindedness and children's age but was unrelated to children's false belief understanding. It is suggested that children of mind-minded parents are more likely to exercise autonomy in socially ambiguous situations. Future studies should focus on the roles of parenting and children's multifaceted autonomy when addressing children's adaptive lie telling. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Measuring Mass-Based Hygroscopicity of Atmospheric Particles through in Situ Imaging

    OpenAIRE

    Piens, DS; Kelly, ST; Harder, TH; Petters, MD; Obrien, RE; Wang, B; Teske, K; Dowell, P; Laskin, A; Gilles, MK

    2016-01-01

    © 2016 American Chemical Society. Quantifying how atmospheric particles interact with water vapor is critical for understanding the effects of aerosols on climate. We present a novel method to measure the mass-based hygroscopicity of particles while characterizing their elemental and carbon functional group compositions. Since mass-based hygroscopicity is insensitive to particle geometry, it is advantageous for probing the hygroscopic behavior of atmospheric particles, which can have irregula...

  1. Influence of nano-AlN particles on thermal conductivity, thermal stability and cure behavior of cycloaliphatic epoxy/trimethacrylate system

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available We have prepared a series of nano-sized aluminium nitride (nano-AlN/cycloaliphatic epoxy/trimethacrylate (TMPTMA systems and investigated their morphology, thermal conductivity, thermal stability and curing behavior. Experimental results show that the thermal conductivity of composites increases with the nano-AlN filler content, the maximum value is up to 0.47 W/(m.K. Incorporation of a small amount of the nano-AlN filler into the epoxy/TMPTMA system improves the thermal stability. For instance, the thermal degradation temperature at 5% weight loss of nano-AlN/epoxy/TMPTMA system with only 1 wt% nano-AlN was improved by ~8ºC over the neat epoxy/TMPTMA system. The effect of nano-AlN particles on the cure behavior of epoxy/TMPTMA systems was studied by dynamic differential scanning calorimetry. The results showed that the addition of silane treated nano-AlN particles does not change the curing reaction mechanism and silane treated nano-AlN particles could bring positive effect on the processing of composite since it needs shorter pre-cure time and lower pre-temperature, meanwhile the increase of glass transition temperature of the nanocomposite improves the heat resistance.

  2. Particle (Soot) Pollution in Port Harcourt Rivers State, Nigeria—Double Air Pollution Burden? Understanding and Tackling Potential Environmental Public Health Impacts

    OpenAIRE

    Okhumode H. Yakubu

    2017-01-01

    Residents of Port Harcourt in Rivers State, Nigeria, and its environs have since the last quarter of 2016 been experiencing adverse environmental impacts of particle (soot) pollution. This “double air pollution burden”—the unresolved prevailing widespread air pollution and the “added” emergence of particle pollution considered an environmental health threat, led to protests against government inaction in some parts of the state. In February 2017, several months following the onset of the poll...

  3. Electroless plating of silver on cenosphere particles and the investigation of its corrosion behavior in composite silicon rubber

    Science.gov (United States)

    Hu, Yong-jun; Zhang, Hai-yan; Cheng, Xiao-ling; Li, Feng; Chen, Tian-li

    2011-01-01

    In this paper, silver coating on the surface of cenosphere particles was prepared by electroless plating method. The adhesion, oxidation resistance and corrosion resistance properties of silver coating mixed in silicone rubber were investigated. The corrosion characteristic of silver coating was evaluated by anodic polarization curves of the silicone rubber composite in sulfuric acid solution. The results showed that the silver coating on the surface of cenosphere particles was smooth and uniform. The silver film was not oxidized and peeling off during preparation of composite silicone rubber. The adhesion between the cenosphere particle and silver film was good enough. The anodic polarization curves of the silicone rubber composite showed typical activation and passivation transformation. The values of corrosion potential, the initiating passive potential and maintaining passivity potential of composites filled with different contents of Ag-coated cenosphere particles were the same and related to the nature of silver coating. The passive current density of composite increased with increase of the amount of Ag-coated cenosphere particles and was inversely proportional to the resistance of silicone rubber composite. The better the conductivity of silicone rubber composite is, the higher corrosion rate will be.

  4. Study on ablation behavior of silicone rubber based insulation material under the condition of boron oxide particles erosion

    Science.gov (United States)

    Zha, B. L.; Shi, Y. A.; Wang, J. J.; Su, Q. D.

    2018-01-01

    Self-designed oxygen-kerosene ablation system was employed to study the ablation characteristics of silicone rubber based thermal insulation materials under the condition of boron oxide particles erosion. The ablation test was designed with a mass fraction of 1.69% boron oxide particles and particles-free, the microstructure and elemental analysis of the specimens before and after ablation were carried out by Scanning Electron Microscopy (SEM) and Energy Dispersion Spectrum (EDS). Experiment results show that the average mass ablation rate of the materials was 0.0099 g•s‑1 and the average ablation rate was -0.025 mm•s‑1 under the condition of pure gas phase ablation; and the average mass ablation rate of the multiphase ablation test group was 0.1775 g•s‑1, whose average ablation rate was 0.437 mm•s‑1 during the ablation process, the boron oxide particles would adhere a molten layer on the flame contact surface of the specimen, which covering the pores on the material surface, blocking the infiltration channel for the oxidizing component and slowing down the oxidation loss rate of the material below the surface, but because the particles erosion was the main reason for material depletion, the combined effect of the above both led to the upward material ablation rates of Silicone Rubber.

  5. Effects of prenatal exposure to diesel exhaust particles on postnatal development, behavior, genotoxicity and inflammation in mice

    Directory of Open Access Journals (Sweden)

    Vogel Ulla

    2008-03-01

    Full Text Available Abstract Background Results from epidemiological studies indicate that particulate air pollution constitutes a hazard for human health. Recent studies suggest that diesel exhaust possesses endocrine activity and therefore may affect reproductive outcome. This study in mice aimed to investigate whether exposure to diesel exhaust particles (DEP; NIST 2975 would affect gestation, postnatal development, activity, learning and memory, and biomarkers of transplacental toxicity. Pregnant mice (C57BL/6; BomTac were exposed to 19 mg/m3 DEP (~1·106 particles/cm3; mass median diameter ≅ 240 nm on gestational days 9–19, for 1 h/day. Results Gestational parameters were similar in control and diesel groups. Shortly after birth, body weights of DEP offspring were slightly lower than in controls. This difference increased during lactation, so by weaning the DEP exposed offspring weighed significantly less than the control progeny. Only slight effects of exposure were observed on cognitive function in female DEP offspring and on biomarkers of exposure to particles or genotoxic substances. Conclusion In utero exposure to DEP decreased weight gain during lactation. Cognitive function and levels of biomarkers of exposure to particles or to genotoxic substances were generally similar in exposed and control offspring. The particle size and chemical composition of the DEP and differences in exposure methods (fresh, whole exhaust versus aged, resuspended DEP may play a significant role on the biological effects observed in this compared to other studies.

  6. Sem Analysis of particles from the 28, 000 B.P El Zaguan debris avalanche deposit, Nevado de Toluca volcano, Central Mexico: evidences of flow behavior during emplacement

    Science.gov (United States)

    Caballero, L.; Capra, L.

    2008-12-01

    The Zaguan deposit originated at 28, 000 yr. B.P from the flank collapse of the Nevado de Toluca volcano, a dacitic stratovolcano of the Transmexican Volcanic Belt. A Scanning Electron Microprobe analysis (SEM) was made to some clasts of this deposit to observe microtextures produced during transport and emplacement of the debris avalanche flow. Particles from 2, 0 and -2 Φ granulometric classes were randomly selected and their surface textures were described. The textures observed were divided in two groups, collision and shear structures indicating different clast interaction. Shear textures were observed predominantly on the basal part of the deposit and consisted of parallel ridges, parallel grooves, scratches and lips. Collision textures were mainly present in the upper part of the deposit and consisted of fractures, percussion marks, and broken or grinded crystals. These characteristics, coupled with field observation, like the presence of clast dikes and deformed lacustrine megaclasts, indicate that the basal part of the debris avalanche was moving in a partially liquefied state, were particles were not able to move freely because of the confinement exerted by the upper part of the flow, so shear stresses dominated. On the contrary, the particles in the upper part were able to move freely so the principal mechanism of interaction between particles was collision. These microscopic textures are in agreement with previously described behavior of emplacement of debris avalanches of volcanic origin, that suggest a stratified flow dominated by different transport and depositional mechanism depending on flow depth and possible fluid content at their base.

  7. Conceptual shifts needed to understand the dynamic interactions of genes, environment, epigenetics, social processes, and behavioral choices.

    Science.gov (United States)

    Jackson, Fatimah L C; Niculescu, Mihai D; Jackson, Robert T

    2013-10-01

    Social and behavioral research in public health is often intimately tied to profound, but frequently neglected, biological influences from underlying genetic, environmental, and epigenetic events. The dynamic interplay between the life, social, and behavioral sciences often remains underappreciated and underutilized in addressing complex diseases and disorders and in developing effective remediation strategies. Using a case-study format, we present examples as to how the inclusion of genetic, environmental, and epigenetic data can augment social and behavioral health research by expanding the parameters of such studies, adding specificity to phenotypic assessments, and providing additional internal control in comparative studies. We highlight the important roles of gene-environment interactions and epigenetics as sources of phenotypic change and as a bridge between the life and social and behavioral sciences in the development of robust interdisciplinary analyses.

  8. Understanding childhood (problem) behaviors from a cultural perspective: comparison of problem behaviors and competencies in Turkish immigrant, Turkish and Dutch children.

    Science.gov (United States)

    Bengi-Arslan, L; Verhulst, F C; van der Ende, J; Erol, N

    1997-11-01

    Parents' reports of problem behaviors in 2,081 Dutch children, 3,127 Turkish children in Ankara and 833 Turkish immigrant children living in The Netherlands, aged 4-18 years, were compared. Dutch and Turkish versions of the Child Behavior Checklist (CBCL) were used. Immigrant children were scored higher than Dutch children on 6 of the 11 CBCL scales, most markedly on the Anxious/Depressed scale. Immigrant children were scored higher than Ankara children on five CBCL scales. However, these differences were much smaller than those found between immigrant and Dutch children. Furthermore, immigrant children's Total Problem scores did not differ from those for Ankara children. Turkish immigrant children have very similar patterns of parent-reported problem behaviors to children living in Turkey, although both groups of Turkish children showed higher levels of parent-reported problem behaviors than Dutch children. The higher scores for Turkish children on the Anxious/Depressed scale compared with their Dutch peers may be explained by cultural differences in parental perception of children's problem behaviors, as well as the threshold for reporting them, or by cultural differences in the prevalence of problems, for instance as the result of cross-cultural differences in child-rearing practice. More research is needed to test the degree to which Turkish immigrant parents tend to preserve their cultural characteristics and child-rearing practices in Dutch society.

  9. Effect of reinforcing particle type on morphology and age-hardening behavior of Al–4.5 wt.% Cu based nanocomposites synthesized through mechanical milling

    International Nuclear Information System (INIS)

    Mostaed, A.; Saghafian, H.; Mostaed, E.; Shokuhfar, A.; Rezaie, H.R.

    2013-01-01

    The effects of reinforcing particle type (SiC and TiC) on morphology and precipitation hardening behavior of Al–4.5%Cu based nanocomposites synthesized via mechanical milling were investigated in the current work. In order to study the microstructure and morphology of mechanically milled powder, X-ray diffraction technique, scanning electron microscopy and high resolution transmission electron microscopy were utilized. Results revealed that at the early stages of mechanical milling, when reinforcing particles are polycrystal, the alloying process is enhanced more in the case of using the TiC particles as reinforcement. But, at the final stages of mechanical milling, when reinforcing particles are single crystal, the alloying process is enhanced more in the case of using the SiC ones. Transmission electron microscopy results demonstrated that Al–4.5 wt.%Cu based nanocomposite powders were synthesized and confirmed that the mutual diffusion of aluminum and copper occurs through the interfacial plane of (200). The hardness results showed that not only does introducing 4 vol.% of reinforcing particles (SiC or TiC) considerably decrease the porosity of the bulk composite samples, but also it approximately doubles the hardness of Al–4.5 wt.%Cu alloy (53.4 HB). Finally, apart from TEM and scanning electron microscopy observation which are localized, a decline in hardness in the TiC and SiC contained samples, respectively, after 1.5 and 2 h aging time at 473 K proves the fact that the size of SiC particles is smaller than the size of the TiC ones. - Highlights: ► HRTEM results show mutual diffusion of Al and Cu occurs through the (200) planes. ► TiC particles enhance alloying process more than the SiC ones at the early stages of MM. ► SiC particles enhance alloying process more than the TiC ones at the final stages of MM

  10. Application of the Theoretical Domains Framework and the Behaviour Change Wheel to Understand Physicians' Behaviors and Behavior Change in Using Temporary Work Modifications for Return to Work: A Qualitative Study.

    Science.gov (United States)

    Horppu, Ritva; Martimo, K P; MacEachen, E; Lallukka, T; Viikari-Juntura, E

    2018-03-01

    Purpose Applying the theoretical domains framework (TDF) and the Behaviour Change Wheel (BCW) to understand physicians' behaviors and behavior change in using temporary work modifications (TWMs) for return to work (RTW). Methods Interviews and focus group discussions were conducted with 15 occupational physicians (OPs). Responses were coded using the TDF and the BCW. Results Key behaviors related to applying TWMs were initiating the process with the employee, making recommendations to the workplace, and following up the process. OP behaviors were influenced by several factors related to personal capability and motivation, and opportunities provided by the physical and social environment. Capability comprised relevant knowledge and skills related to applying TWMs, remembering to initiate TWMS and monitor the process, and being accustomed to reflective practice. Opportunity comprised physical resources (e.g., time, predefined procedures, and availability of modified work at companies), and social pressure from stakeholders. Motivation comprised conceptions of a proper OP role, confidence to carry out TWMs, personal RTW-related goals, beliefs about the outcomes of one's actions, feedback received from earlier cases, and feelings related to applying TWMs. OPs' perceived means to target these identified factors were linked to the following BCW intervention functions: education, training, persuasion, environmental restructuring, and enablement. The results suggest that at least these functions should be considered when designing future interventions. Conclusions Our study illustrates how theoretical frameworks TDF and BCW can be utilized in a RTW context to understand which determinants of physicians' behavior need to be targeted, and how, to promote desired behaviors.

  11. Adsorption behaviors of surface active reagents on barium ferrite magnetic fine particles; Barium ferrite jisei biryushi eno hymen shorizai kyuchaku

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, M.; Otani, T.; Masuko, T. [Yamagata University, Yamagata (Japan). Faculty of Engineering

    1998-06-10

    The adsorption mode of lecithin (dioleoylphosphatidylcholine) or [3-(methacryloyloxy)propyl] trimethoxysilane (MPS) onto barium ferrite magnetic particles has been investigated by measurements of changes in solution concentration of the surfactant. Both adsortion isotherms of the surface active reagents on barium ferrite particles indicated to be of the Langmuir type. The occupied areas per one molecule on the surface of barium ferrite particles were estimated to be about 70 angstrom{sup 2}/molecule for lecithin and 22 angstrom{sup 2}/molecule for MPS at their saturated adsorption. In X-ray photoelectron spectroscopy (XPS) measurements for the adsorbed lecithin layer, the peak position in the binding energy distribution for the P (2p) photoelectron was observed to shift into slightly higher values with increasing amount of adsorbed lecithin. This implies that dipole-dipole interactions among the lecithin molecules become stronger because of increased high molecular packing in the adsorption layers. However, the peak position for the Si (2p) photoelectron remains almost unchanged due to slight interaction among the adsorbing functional groups onto the particles. 16 refs., 16 figs., 3 tabs.

  12. Auroral particles

    Science.gov (United States)

    Evans, David S.

    1987-01-01

    The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries.

  13. Behavior of Particle Depots in Molten Silicon During Float-Zone Growth in Strong Static Magnetic Fields

    Science.gov (United States)

    Jauss, T.; SorgenFrei, T.; Croell, A.; Azizi, M.; Reimann, C.; Friedrich, J.; Volz, M. P.

    2014-01-01

    In the photovoltaics industry, the largest market share is represented by solar cells made from multicrystalline silicon, which is grown by directional solidification. During the growth process, the silicon melt is in contact with the silicon nitride coated crucible walls and the furnace atmosphere which contains carbon monoxide. The dissolution of the crucible coating, the carbon bearing gas, and the carbon already present in the feedstock, lead to the precipitation of silicon carbide, and silicon nitride, at later stages of the growth process. The precipitation of Si3N4 and SiC particles of up to several hundred micrometers in diameter leads to severe problems during the wire sawing process for wafering the ingots. Furthermore the growth of the silicon grains can be negatively influenced by the presence of particles, which act as nucleation sources and lead to a grit structure of small grains and are sources for dislocations. If doped with Nitrogen from the dissolved crucible coating, SiC is a semi conductive material, and can act as a shunt, short circuiting parts of the solar cell. For these reasons, the incorporation of such particles needs to be avoided. In this contribution we performed model experiments in which the transport of intentionally added SiC particles and their interaction with the solid-liquid interface during float zone growth of silicon in strong steady magnetic fields was investigated. SiC particles of 7µm and 60µm size are placed in single crystal silicon [100] and [111] rods of 8mm diameter. This is achieved by drilling a hole of 2mm diameter, filling in the particles and closing the hole by melting the surface of the rod until a film of silicon covers the hole. The samples are processed under a vacuum of 1x10(exp -5) mbar or better, to prevent gas inclusions. An oxide layer to suppress Marangoni convection is applied by wet oxidation. Experiments without and with static magnetic field are carried out to investigate the influence of melt

  14. Sex Differences in Affect Behaviors, Desired Social Responses, and Accuracy at Understanding the Social Desires of Other People

    Directory of Open Access Journals (Sweden)

    Jacob M. Vigil

    2008-07-01

    Full Text Available I recently proposed a socio-relational framework that suggests that phenotypic variation in the expression of discrete affect behaviors (e.g., expressed anger vs. sadness may reflect two basic dimensions of behavioral response. The first dimension is the motivation to selectively attract or avoid interactions with different people. The second dimension is the behavioral display of either personal capacity or trustworthiness cues, often through the expression of dominant and submissive behaviors, respectively (Vigil, in press. Sex differences in affect behaviors (e.g., externalizing vs. internalizing displays may reflect developmental sensitivities to advertise capacity and trustworthiness cues somewhat differently, due to the unique social dynamics and relational constraints under which males and females evolved. In this study, I use a series of self-report questionnaires to examine two basic assumptions of the framework. The first assumption is that sex differences in nonverbal affect behaviors (aggression vs. crying reflect the desire for, and are effective for causing other people to either avoid or comfort the individual, respectively. I hypothesized that males would report a greater likelihood of responding to various distress moods with aggressive, rather than crying behaviors, and that males would desire, and believe male peers similarly desire distancing responses from others when feeling these moods. Instead, females were hypothesized to report more crying behaviors, and to desire, and believe female peers desire more comforting responses from others. The second assumption is that people are more accurate at inferring the desired social responses (i.e., to be left alone or comforted when experiencing distress of same-sex, rather than opposite-sex peers. I hypothesized that people's beliefs of same-sex peers are more similar to the self-reported desires of the male and female participants, themselves, than their beliefs of opposite

  15. Particle adhesion and removal

    CERN Document Server

    Mittal, K L

    2015-01-01

    The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal.  The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments.  Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand  particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and  n

  16. Selectively-informed particle swarm optimization.

    Science.gov (United States)

    Gao, Yang; Du, Wenbo; Yan, Gang

    2015-03-19

    Particle swarm optimization (PSO) is a nature-inspired algorithm that has shown outstanding performance in solving many realistic problems. In the original PSO and most of its variants all particles are treated equally, overlooking the impact of structural heterogeneity on individual behavior. Here we employ complex networks to represent the population structure of swarms and propose a selectively-informed PSO (SIPSO), in which the particles choose different learning strategies based on their connections: a densely-connected hub particle gets full information from all of its neighbors while a non-hub particle with few connections can only follow a single yet best-performed neighbor. Extensive numerical experiments on widely-used benchmark functions show that our SIPSO algorithm remarkably outperforms the PSO and its existing variants in success rate, solution quality, and convergence speed. We also explore the evolution process from a microscopic point of view, leading to the discovery of different roles that the particles play in optimization. The hub particles guide the optimization process towards correct directions while the non-hub particles maintain the necessary population diversity, resulting in the optimum overall performance of SIPSO. These findings deepen our understanding of swarm intelligence and may shed light on the underlying mechanism of information exchange in natural swarm and flocking behaviors.

  17. Absorption and scattering of light by small particles

    CERN Document Server

    Bohren, Craig F

    1983-01-01

    Absorption and Scattering of Light by Small Particles. Treating absorption and scattering in equal measure, this self-contained, interdisciplinary study examines and illustrates how small particles absorb and scatter light. The authors emphasize that any discussion of the optical behavior of small particles is inseparable from a full understanding of the optical behavior of the parent material-bulk matter. To divorce one concept from the other is to render any study on scattering theory seriously incomplete. Special features and important topics covered in this book include:. * Classical theor

  18. Understanding differences in sexting behaviors across gender, relationship status, and sexual identity, and the role of expectancies in sexting.

    Science.gov (United States)

    Dir, Allyson L; Coskunpinar, Ayca; Steiner, Jennifer L; Cyders, Melissa A

    2013-08-01

    Sexting, or the exchange of sexually explicit material via Internet social-networking site or mobile phone, is an increasingly prevalent behavior. The study sought to (1) identify expectancies regarding sexting behaviors, (2) examine how demographics (i.e., gender, sexual identity, relationship status) might be differentially related to sexting expectancies and behaviors, and (3) examine whether these concurrent relationships are consistent with a theoretical causal model in which sexting expectancies influence sexting behaviors. The sample consisted of 278 undergraduate students (mean age=21.0 years, SD=4.56; 53.8% female; 76.3% caucasian). Factor analyses supported the validity and reliability of the Sextpec