Does Playing Pay? The Fitness-Effect of Free Play during Childhood

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Werner Greve

2014-04-01

Full Text Available Evolutionary developmental psychology claims that the sequences and processes of human development, in fact the mere fact of ontogeny itself, have to be viewed as evolutionary products. However, although the functional benefits of childish behavior (child playing for cognitive and emotional development have been shown repeatedly, claiming evolutionary adaptiveness of playing in childhood suggests that childish play supports evolutionary success in mature stages of development. This hypothesis is tested in a study with N = 134 adults (93 females; age range 20–66 years. Participants were asked to recollect their play experiences during childhood in detail, and to report their current developmental status with respect to several aspects of social success. Results show that the opportunity for and the promotion of free play in childhood significantly predict some indicators of social success. Additional analyses strive to explore mediating processes for this relationship. In particular, the mediating role of individual adaptivity (flexibility of goal adjustment is investigated. Results suggest that freely playing in childhood promotes developmental resources, in particular individual adaptivity in adulthood, which, in turn, promote developmental success.

Does playing pay? The fitness-effect of free play during childhood.

Science.gov (United States)

Greve, Werner; Thomsen, Tamara; Dehio, Cornelia

2014-04-29

Evolutionary developmental psychology claims that the sequences and processes of human development, in fact the mere fact of ontogeny itself, have to be viewed as evolutionary products. However, although the functional benefits of childish behavior (child playing) for cognitive and emotional development have been shown repeatedly, claiming evolutionary adaptiveness of playing in childhood suggests that childish play supports evolutionary success in mature stages of development. This hypothesis is tested in a study with N=134 adults (93 females; age range 20-66 years). Participants were asked to recollect their play experiences during childhood in detail, and to report their current developmental status with respect to several aspects of social success. Results show that the opportunity for and the promotion of free play in childhood significantly predict some indicators of social success. Additional analyses strive to explore mediating processes for this relationship. In particular, the mediating role of individual adaptivity (flexibility of goal adjustment) is investigated. Results suggest that freely playing in childhood promotes developmental resources, in particular individual adaptivity in adulthood, which, in turn, promote developmental success.

Electromechanical response of a curved piezoelectric nanobeam with the consideration of surface effects

International Nuclear Information System (INIS)

Yan Zhi; Jiang Liying

2011-01-01

This work investigates the electromechanical response of a curved piezoelectric nanobeam with the consideration of surface effects through the surface-layer-based model and the generalized Young-Laplace equations. For nanoscale piezoelectric structures, the surface effects also include surface piezoelectricity in addition to the residual surface stress and surface elasticity for elastic nanomaterials. A Euler-Bernoulli curved beam theory is used to get the explicit solutions for the electroelastic fields of a curved cantilever beam when subjected to mechanical and electrical loads. In order to apply the appropriate boundary conditions on the beam, effective axial force, shear force and moment are derived. The results indicate that the surface effects play a significant role in the electroelastic fields and the piezoelectric response of the curved piezoelectric nanobeam. It is also found that the coupling of the residual surface stress, the surface elasticity and the surface piezoelectricity may be dramatic despite that the influence of the individual one is small under some circumstances. This study is expected to be useful for design and applications of curved beam based piezoelectric nanodevices, such as the curved nanowires/nanobelts or nanorings as nanoswitches or nanoactuators for displacement control purpose.

Short-term effects of playing computer games on attention.

Science.gov (United States)

Tahiroglu, Aysegul Yolga; Celik, Gonca Gul; Avci, Ayse; Seydaoglu, Gulsah; Uzel, Mehtap; Altunbas, Handan

2010-05-01

The main aim of the present study is to investigate the short-term cognitive effects of computer games in children with different psychiatric disorders and normal controls. One hundred one children are recruited for the study (aged between 9 and 12 years). All participants played a motor-racing game on the computer for 1 hour. The TBAG form of the Stroop task was administered to all participants twice, before playing and immediately after playing the game. Participants with improved posttest scores, compared to their pretest scores, used the computer on average 0.67 +/- 1.1 hr/day, while the average administered was measured at 1.6 +/- 1.4 hr/day and 1.3 +/- 0.9 hr/day computer use for participants with worse or unaltered scores, respectively. According to the regression model, male gender, younger ages, duration of daily computer use, and ADHD inattention type were found to be independent risk factors for worsened posttest scores. Time spent playing computer games can exert a short-term effect on attention as measured by the Stroop test.

Atomoxetine/Methylphenidate Effects on Social Play Behavior

Directory of Open Access Journals (Sweden)

J Gordon Millichap

2015-02-01

Full Text Available Researchers at Utrecht University, The Netherlands, and University “Roma Tre,” Rome, Italy, studied the neural substrates of the previously identified social play-suppressant effects of methylphenidate (MPH and atomoxetine, drugs widely used for the treatment of attention-deficit hyperactivity disorder (ADHD.

The influence of the playing surface on the exercise intensity of small-sided recreational soccer games

DEFF Research Database (Denmark)

Brito, João; Krustrup, Peter; Rebelo, António

2012-01-01

This study aimed to analyze the influence of the playing surface on movement pattern, physical loading, perceived exertion, and fatigue development during small-sided recreational soccer games. Time-motion, heart rate, blood lactate, and perceived exertion were measured for 16 recreational players...... aged 22 (range: 19-35)yrs. During 5-a-side soccer games on 3 different field surfaces: sand, artificial turf, and asphalt. Jump and sprint tests were performed prior to and after each game. Total distance covered was higher on asphalt and turf than on sand (3.89±0.04 and 3.73±0.12 vs. 2.59±0.21km; p90...

Influence of surface effects on the pull-in instability of NEMS electrostatic switches

Energy Technology Data Exchange (ETDEWEB)

Ma, Jianming Bryan; Jiang Liying; Asokanthan, Samuel F, E-mail: lyjiang@eng.uwo.ca, E-mail: sasokanthan@eng.uwo.ca [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON, N6A 5B9 (Canada)

2010-12-17

The influence of surface effects, including residual surface stress and surface elasticity, on the pull-in instability of electrostatic switches in nanoelectromechanical systems (NEMS) is studied using an Euler-Bernoulli beam model. This model is inherently nonlinear due to the driving electrostatic force and Casimir force which become dominant at the nanoscale. Since no exact solutions are available for the resulting nonlinear differential equation, He's homotopy perturbation method (HPM) is used to get the approximate analytical solutions to the static bending of NEMS switches, which are validated by numerical solutions of the finite difference method (FDM). The results demonstrate that surface effects play a significant role in the selection of basic design parameters of NEMS switches, such as static deflection, pull-in voltage and detachment length. Surface effects on low-voltage actuation windows are also characterized for these switches. The present study is envisaged to provide useful insights for the design of NEMS switches.

Effect of surface states on the electrochemical behaviour of single crystal n-ZnSe photoelectrode

International Nuclear Information System (INIS)

El-Dessouki, M.S.

1987-10-01

Surface Photovoltage Spectroscopy (SPS) technique has been used to detect the surface states of ZnSe (110) surfaces. Aqueous electrolyte/ZnSe junction has been electrochemically investigated in dark and under illumination. The effect of surface states on the kinetics of charge transfer through the semiconductor-electrolyte (S/E) junction has been discussed. The low leakage and photocurrents measured by the application of DC bias were referred to the blocking nature of S/E interface, in which the localized and induced surface states play an important role. (author). 19 refs, 4 figs

The Play Factor: Effect of Social Skills Group Play Therapy on Adolescent African-American Males

Science.gov (United States)

Earls, Melissa K.

2009-01-01

The purpose of this study was to examine the effectiveness of Social Skills Group Play Therapy on remedying the social skills deficits of adolescent African-American males. Additionally, the study investigated whether age and grade level impacted the outcome of the intervention. The participants were adolescent African-American males ages 10 to…

Effect of combined teaching method (role playing and storytelling ...

African Journals Online (AJOL)

Effect of combined teaching method (role playing and storytelling) on creative ... Remember me ... Background and Purpose: Storytelling promotes imagination and satisfies curiosity in children and creates learning opportunities in them.

Effect of volume and surface charges on discharge structure of glow dielectric barrier discharge

Energy Technology Data Exchange (ETDEWEB)

Xu, Shao-Wei; He, Feng; Wang, Yu; Li, Lulu; Ouyang, Ji-Ting [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)

2013-08-15

The effect of volume and surface charges on the structure of glow dielectric barrier discharge (DBD) has been investigated numerically by using two-dimensional (2D) fluid modeling. The local increase of volume or surface charges induces a kind of activation-inhibition effect, which enhances the local volume discharge and inhibits the discharge in neighborhoods, resulting in non-uniform discharge. The activation-inhibition effect due to the non-uniform volume and/or surface charges depends on the non-uniformity itself and the applied voltage. The activation-inhibition of non-uniform charges has different effects on the volume charges and the accumulated surface charges. The distribution of remaining free charges (seed electrons) in volume at the beginning of voltage pulse plays a key role for the glow DBD structure, resulting in a patterned DBD, when the seed electrons are non-uniform at higher frequency and moderate voltage or uniform DBD, when the seed electrons are uniform at lower frequency or high voltage. The distribution of surface charges is not the determining factor but a result of the formed DBD structure.

Effect of playing tactics on goal scoring in Norwegian professional soccer.

Science.gov (United States)

Tenga, Albin; Holme, Ingar; Ronglan, Lars Tore; Bahr, Roald

2010-02-01

Methods that include an assessment of opponent interactions are thought to provide a more valid analysis of team match performance. The purpose of this study was to examine the effect of playing tactics on goal scoring by assessing opponent interactions in Norwegian elite soccer. The sample included 203 team possessions leading to goals (cases) and 1688 random team possessions (control group) from 163 of 182 (90%) matches played in the men's professional league during the 2004 season. Multidimensional qualitative data using ten ordered categorical variables were obtained to characterize each team possession. The proportion of goals scored during counterattacks (52%) was higher than during elaborate attacks (48%), while for the control group the proportion using elaborate attacks (59%) was higher than when using counterattacks (41%) (P = 0.002). Multiple logistic regression analyses showed that, for the main variable "team possession type", counterattacks were more effective than elaborate attacks when playing against an imbalanced defence (OR = 1.64; 95% confidence interval: 1.03 to 2.61; P = 0.038). Assessment of opponent interactions is critical to evaluate the effectiveness of offensive playing tactics on the probability of scoring goals, and improves the validity of team match-performance analysis in soccer.

Simulations of surface stress effects in nanoscale single crystals

Science.gov (United States)

Zadin, V.; Veske, M.; Vigonski, S.; Jansson, V.; Muszinsky, J.; Parviainen, S.; Aabloo, A.; Djurabekova, F.

2018-04-01

Onset of vacuum arcing near a metal surface is often associated with nanoscale asperities, which may dynamically appear due to different processes ongoing in the surface and subsurface layers in the presence of high electric fields. Thermally activated processes, as well as plastic deformation caused by tensile stress due to an applied electric field, are usually not accessible by atomistic simulations because of the long time needed for these processes to occur. On the other hand, finite element methods, able to describe the process of plastic deformations in materials at realistic stresses, do not include surface properties. The latter are particularly important for the problems where the surface plays crucial role in the studied process, as for instance, in the case of plastic deformations at a nanovoid. In the current study by means of molecular dynamics (MD) and finite element simulations we analyse the stress distribution in single crystal copper containing a nanovoid buried deep under the surface. We have developed a methodology to incorporate the surface effects into the solid mechanics framework by utilizing elastic properties of crystals, pre-calculated using MD simulations. The method leads to computationally efficient stress calculations and can be easily implemented in commercially available finite element software, making it an attractive analysis tool.

Sibling Group Play Therapy: An Effective Alternative with an Elective Mute Child.

Science.gov (United States)

Barlow, Karen; And Others

1986-01-01

Presents the case study of an elective mute child. Describes the effects of sibling play therapy and lists implications for school counselors who might use group or sibling play therapy in their developmental guidance programs. (ABB)

THE EFFECTIVENESS OF PLAY THERAPY AND MUSICAL THERAPY IN REDUCING THE HOSPITALIZATION STRESS

Directory of Open Access Journals (Sweden)

Yuni Sufyanti Arief

2017-07-01

Full Text Available Introduction: Hospitalization in pediatric patients may caused an anxiety and stress in all age levels. Several techniques can be applied to reduced hospitalization stress in children, such as playing therapy and music therapy. The objective of this study was to analyze the difference of effectiveness between both therapies in reducing the hospitalization stress in 4-6 years old children. Method: A quasy-experimental pre-posttest design was used in this study. There were 18 respondents, divided into three groups, i.e. group one receiving playing therapy, group two receiving music therapy and the last group as control group. Data were collected by using observation sheet before and after intervention to recognize the hospitalization stress. Data were analyzed by using Wilcoxon Signed Rank Test and Mann Whitney U Test with significance level of α<0.05. Result: Result showed that playing therapy and music therapy had significant effect to reduce the hospitalization stress with p=0.027 for play therapy, p=0.024 for musical therapy, and p=0.068 for control. Mann Whitney U Test revealed that there were no difference in the effectiveness of play therapy and musical therapy in reducing the hospitalization stress with p=0.009 for play therapy and control group, p=0.012 for music therapy and control group, and p=0.684 for playing therapy and musical therapy. Discussion: It can be concluded that play therapy and musical therapy are equally effective to reduce the hospitalization stress in children. It’s recommended for nurses in pediatric ward to do  playg therapy and musical therapy periodically.

Effect of surface texturing on friction properties of WC/Co cemented carbide

International Nuclear Information System (INIS)

Wu, Ze; Deng, Jianxin; Xing, Youqiang; Cheng, Hongwei; Zhao, Jun

2012-01-01

Highlights: ► Tribological properties of surface textured WC/Co cemented carbide were studied. ► Textured surfaces have better performance of antifriction and antiwear. ► Area density of textures has significant effect on tribological performance. -- Abstract: An experimental study was carried out to investigate the tribological properties of different surface textured WC/Co cemented carbide. The influence of applied load, sliding speed and area density of textures on frictional performance of surface textured patterns was investigated by Taguchi method. Results show that the textured surfaces filled with molybdenum disulfide solid lubricants can reduce the average friction coefficient, wear rates of Ti–6Al–4V alloy balls and adhesion of Ti–6Al–4V alloy materials on the worn track of cemented carbide compared with un-textured ones. Variance analysis of the experimental data indicates that the area density of textures plays major contribution of both average friction coefficient and wear rate of Ti–6Al–4V alloy balls. Higher area density of textures is beneficial to improve tribological performance of the cemented carbide samples. Sliding speed seems to have no effect on the tribological performance of textured surfaces within the reliability interval of 90%. Applied load has effect on both average friction coefficient and wear rate of Ti–6Al–4V alloy balls at the reliability interval of 95%.

Nonthermal Effects of Photon Illumination on Surface Diffusion

International Nuclear Information System (INIS)

Ditchfield, R.; Llera-Rodriguez, D.; Seebauer, E.G.

1998-01-01

Nonthermal influences of photon illumination on surface diffusion at high temperatures have been measured experimentally for the first time. Activation energies and preexponential factors for diffusion of germanium and indium on silicon change substantially in response to illumination by photons having energies greater than the substrate band gap. Results depend on doping type. Ionization of surface vacancies by photogenerated charge carriers seems to play a key role. The results have significant implications for aspects of microelectronics fabrication governed by surface mobility. copyright 1998 The American Physical Society

Final state effects in photoemission studies of Fermi surfaces

International Nuclear Information System (INIS)

Kurtz, Richard L; Browne, Dana A; Mankey, Gary J

2007-01-01

Photoelectron spectroscopy is one of the most important methods for extracting information about the Fermi surface (FS) of materials. An electron photoexcited from the FS is emitted from the crystal conserving the parallel momentum, k parallel , while the perpendicular momentum k perpendicular is reduced due to the surface potential barrier. A simple interpretation of the process assumes the final state is free-electron-like allowing one to 'map' the detected photoelectron back to its initial k momentum. There are multiple final state effects that can complicate the interpretation of photoelectron data and these effects are reviewed here. These can involve both energy and k broadening, which can give rise to shadow or ghost FS contours, scattering and final state diffraction effects that modify intensities, and matrix element effects which reflect the symmetries of the states involved and can be highly dependent on photon polarization. These matrix elements result in contours of photoelectron intensity that follow the dispersion in k-space of the initial state, the FS, and the final state. Locations where intensities go to zero due to matrix element and symmetry effects can result in gaps where FS contours 'disappear'. Recognition that these effects can play a significant role in determining the measured angular distributions is crucial in developing an informed model of where the FS contours actually lie in relation to measured intensity contours

Effects of Chinese opera on the reproductions of Ibsen's plays

Directory of Open Access Journals (Sweden)

Miriam Leung Che LAU

2015-02-01

Full Text Available As part of a globalized phenomenon, the reproductions of Ibsen’s plays on the Chinese theatrical stage increasingly focus upon the exploration and expansion of new cultural forms, as Patrice Pavis defines interculturalism as “grasping the dialectical of exchanges of civilities between cultures”. However, how do we evaluate the effectiveness of the many “intercultural” productions that surround us today? I attempt to answer this question by comparing two Chinese reproductions of Ibsen’s plays that employ elements of Chinese opera on varying scales. The first one is a total transformation of Hedda Gabler into a Hangzhou yue opera form, Xin Bi Tian Gao (Aspirations Higher than the Sky, 心比天高 in 2006. As part of the yue opera tradition, Hedda Gabler was staged in an all-female cast. The second one is a fragmented insertion of a Peking opera excerpt into the staging of A Doll’s House by the National Experimental Theatre of China in 1998. One of the highlights of the play is a Norwegian actress, who plays Nora, singing and dancing a short Peking opera excerpt, thus replacing the tarantella dance in the original play. Contextualising the multiple perspectives towards interculturalism by Patrice Pavis, Richard Schechner and Rustom Bharucha, I aim to explore how the appropriation of Chinese opera in such performances might strengthen or weaken the reciprocal flows between the source and target cultures in Pavis’s “hourglass model”, and whether the initial attempt of revitalising both Chinese and Western art forms has backfired and misproduced Bertolt Brecht’s alienation effect directed at the contemporary audience.

Exploring the effects of playing formations on tactical behaviour and external workload during football small-sided games.

Science.gov (United States)

Baptista, Jorge; Travassos, Bruno; Gonçalves, Bruno; Mourão, Paulo; Viana, João L; Sampaio, Jaime

2018-01-04

This study aimed to identify the effects of playing formations on tactical behaviour and external workload during football small-sided games. Twenty-three semi-professional footballers integrated three different playing formations in a 7-a-side small-sided game, according to their specific player positions: team 4:3:0 (4 defenders, 3 midfielders); team 4:1:2 (4 defenders, 1 midfielder, 2 forwards); and team 0:4:3 (4 midfielders, 3 forwards). Based on players' movement trajectories, the following individual and collective tactical variables were calculated: total distance covered and distance covered while walking, jogging, running and sprinting, distance from each player to both own and opponent's team centroid (Dist CG and Dist OPP CG, respectively), individual area, team length, team width and surface area. Approximate entropy (ApEn) was computed to identify the regularity of each variable. The team 4:3:0 promoted players' space exploration with moderate physical efforts. The team 4:1:2 promoted compactness and regularity of the team with increase in the physical efforts. The team 0:4:3 promoted team balance and adaptability on space coverage with increase in physical efforts. Concluding, different playing formations support different game dynamics, and variations on external load were directly linked with the variations on tactical behaviour. The analysis tactical behaviour through quantification of variability of patterns of play and quantification of distance covered at different velocities were the most useful information for the analysis of the effects of practice task manipulations. Therefore, in a practical sense, strength and conditioning coaches should plan and monitor these tasks in interaction with the head coaches.

Effect of water table dynamics on land surface hydrologic memory

Science.gov (United States)

Lo, Min-Hui; Famiglietti, James S.

2010-11-01

The representation of groundwater dynamics in land surface models has received considerable attention in recent years. Most studies have found that soil moisture increases after adding a groundwater component because of the additional supply of water to the root zone. However, the effect of groundwater on land surface hydrologic memory (persistence) has not been explored thoroughly. In this study we investigate the effect of water table dynamics on National Center for Atmospheric Research Community Land Model hydrologic simulations in terms of land surface hydrologic memory. Unlike soil water or evapotranspiration, results show that land surface hydrologic memory does not always increase after adding a groundwater component. In regions where the water table level is intermediate, land surface hydrologic memory can even decrease, which occurs when soil moisture and capillary rise from groundwater are not in phase with each other. Further, we explore the hypothesis that in addition to atmospheric forcing, groundwater variations may also play an important role in affecting land surface hydrologic memory. Analyses show that feedbacks of groundwater on land surface hydrologic memory can be positive, negative, or neutral, depending on water table dynamics. In regions where the water table is shallow, the damping process of soil moisture variations by groundwater is not significant, and soil moisture variations are mostly controlled by random noise from atmospheric forcing. In contrast, in regions where the water table is very deep, capillary fluxes from groundwater are small, having limited potential to affect soil moisture variations. Therefore, a positive feedback of groundwater to land surface hydrologic memory is observed in a transition zone between deep and shallow water tables, where capillary fluxes act as a buffer by reducing high-frequency soil moisture variations resulting in longer land surface hydrologic memory.

Group play

DEFF Research Database (Denmark)

Tychsen, Anders; Hitchens, Michael; Brolund, Thea

2008-01-01

Role-playing games (RPGs) are a well-known game form, existing in a number of formats, including tabletop, live action, and various digital forms. Despite their popularity, empirical studies of these games are relatively rare. In particular there have been few examinations of the effects of the v......Role-playing games (RPGs) are a well-known game form, existing in a number of formats, including tabletop, live action, and various digital forms. Despite their popularity, empirical studies of these games are relatively rare. In particular there have been few examinations of the effects...... of the various formats used by RPGs on the gaming experience. This article presents the results of an empirical study, examining how multi-player tabletop RPGs are affected as they are ported to the digital medium. Issues examined include the use of disposition assessments to predict play experience, the effect...... of group dynamics, the influence of the fictional game characters and the comparative play experience between the two formats. The results indicate that group dynamics and the relationship between the players and their digital characters, are integral to the quality of the gaming experience in multiplayer...

Electrolyte effects on the surface chemistry and cellular response of anodized titanium

International Nuclear Information System (INIS)

Ohtsu, Naofumi; Kozuka, Taro; Hirano, Mitsuhiro; Arai, Hirofumi

2015-01-01

Highlights: • Ti samples were anodized using various electrolytes. • Anodization decreased carbon adsorption, improving hydrophilicity. • Improved hydrophilicity led to improved cellular attachment. • Only one electrolyte showed any heteroatom incorporation into the TiO 2 layer. • Choice of electrolyte played no role on the effects of anodization. - Abstract: Anodic oxidation of titanium (Ti) material is used to enhance biocompatibility, yet the effects of various electrolytes on surface characteristics and cellular behavior have not been completely elucidated. To investigate this topic, oxide layers were produced on Ti substrates by anodizing them in aqueous electrolytes of (NH 4 ) 2 O·5B 2 O 3 , (NH 4 ) 2 SO 4 , or (NH 4 ) 3 PO 4 , after which their surface characteristics and cellular responses were examined. Overall, no surface differences between the electrolytes were visually observed. X-ray photoelectron spectroscopy (XPS) revealed that the anodized surfaces are composed of titanium dioxide (TiO 2 ), while incorporation from electrolyte was only observed for (NH 4 ) 3 PO 4 . Surface adsorption of carbon contaminants during sterilization was suppressed by anodization, leading to lower water contact angles. The attachment of MC3T3-E1 osteoblast-like cells was also improved by anodization, as evidenced by visibly enlarged pseudopods. This improved attachment performance is likely due to TiO 2 formation. Overall, electrolyte selection showed no effect on either surface chemistry or cellular response of Ti materials

Physical characteristics of satellite surfaces

International Nuclear Information System (INIS)

Veverka, J.; Thomas, P.; Johnson, T.V.; Matson, D.; Housen, K.

1986-01-01

Both exogenic and endogenic effects have been proposed to explain the major observed characteristics of satellite surfaces. The current view is that the basic properties of most surfaces result from the intrinsic composition of a body and its geologic history. Exogenic effects have, however, played a role in modifying the appearance of nearly all surfaces. The most important exogenic effect is impact cratering, one manifestation of which is the production of micrometeoroid gardened regoliths on airless bodies. On large, silicate bodies the micrometeoroid bombardment can produce an optically mature, dark agglutinate-rich soil; the nature of regoliths on predominantly icy satellites remains uncertain. Direct accumulation of infalling material does not appear to play a major role in modifying most surfaces. Solar wind radiation effects have not altered greatly the optical properties of solar system objects; magnetospheric charged particles may have modified the optical properties of some outer planet satellites (e.g., sulfur ion bombardment in the case of some of the satellites of Jupiter). Other effects, such as aeolian and liquid/solid chemical weathering, may be important on satellites with atmospheres like Titan and Triton

The Effects of In-Service Training on Teachers' Beliefs and Practices in Children's Play

Science.gov (United States)

Vu, Jennifer A.; Han, Myae; Buell, Martha J.

2015-01-01

Early childhood educators are often aware of the general importance of play in children's development; however, they are often less aware of how play can support both academic and social learning and what their own roles can be in children's play. In this study, we examined the effect that professional development training about play would have on…

Confronting Prejudiced Comments: Effectiveness of a Role-Playing Exercise

Science.gov (United States)

Lawson, Timothy J.; McDonough, Tracy A.; Bodle, James H.

2010-01-01

We examined whether a role-playing exercise, similar to that developed by Plous (2000), increases students' ability to generate effective responses to prejudiced comments. We assessed social psychology students' (n = 23) ability to respond to prejudiced comments before and after the exercise, and compared their performance to that of 2 other…

The Effect Playing Online GamesOn The Players

OpenAIRE

Christopher Akami J.S

2014-01-01

Online game is a game that requires internet connection to play and while playing a lot of individuals do not care about a lot of things. Games can also influence the gamers to have bad behavior. However, playing online games can be exciting although only playing for a moment.

Effect of surface stress and irregularity of the interface on the ...

Indian Academy of Sciences (India)

Surface stress; irregularity of the interface; magneto-elastic crustal ... stress plays a vital role in the propagation of waves due to the fact that the surface of a ...... Mumbai, for his computational help towards the numerical calculations and graphs.

The Effect Playing Online GamesOn The Players

Directory of Open Access Journals (Sweden)

Christopher Akami J.S

2014-11-01

Full Text Available Online game is a game that requires internet connection to play and while playing a lot of individuals do not care about a lot of things. Games can also influence the gamers to have bad behavior. However, playing online games can be exciting although only playing for a moment.

Effects of Static Stretching and Playing Soccer on Knee Laxity

NARCIS (Netherlands)

Baumgart, Christian; Gokeler, Alli; Donath, Lars; Hoppe, Matthias W.; Freiwald, Juergen

Objective: This study investigated exercise-induced effects of static stretching and playing soccer on anterior tibial translation (ATT) of the knee joint. Design: Randomized controlled trial. Setting: University biomechanics laboratory. Participants: Thirty-one athletes were randomly assigned into

Effects of Static Stretching and Playing Soccer on Knee Laxity

NARCIS (Netherlands)

Baumgart, Christian; Gokeler, Alli; Donath, Lars; Hoppe, Matthias W.; Freiwald, Juergen

2015-01-01

Objective: This study investigated exercise-induced effects of static stretching and playing soccer on anterior tibial translation (ATT) of the knee joint. Design: Randomized controlled trial. Setting: University biomechanics laboratory. Participants: Thirty-one athletes were randomly assigned into

Spatial distribution of surface EMG on trapezius and lumbar muscles of violin and cello players in single note playing.

Science.gov (United States)

Afsharipour, Babak; Petracca, Francesco; Gasparini, Mauro; Merletti, Roberto

2016-12-01

Musicians activate their muscles in different patterns, depending on their posture, the instrument being played, and their experience level. Bipolar surface electrodes have been used in the past to monitor such activity, but this method is highly sensitive to the location of the electrode pair. In this work, the spatial distribution of surface EMG (sEMG) of the right trapezius and right and left erector spinae muscles were studied in 16 violin players and 11 cello players. Musicians played their instrument one string at a time in sitting position with/without backrest support. A 64 sEMG electrode (16×4) grid, 10mm inter-electrode distance (IED), was placed over the middle and lower trapezius (MT and LT) of the bowing arm. Two 16×2 electrode grids (IED=10mm) were placed on the left and right erector spinae muscles. Subjects played each of the four strings of the instrument either in large (1bow/s) or detaché tip/tail (8bows/s) bowing in two sessions (two days). In each of two days, measurements were repeated after half an hour of exercise to see the effect of exercise on the muscle activity and signal stability. A "muscle activity index" (MAI) was defined as the spatial average of the segmented active region of the RMS map. Spatial maps were automatically segmented using the watershed algorithm and thresholding. Results showed that, for violin players, sliding the bow upward from the tip toward the tail results in a higher MAI for the trapezius muscle than a downward bow. On the contrary, in cello players, higher MAI is produced in the tail to tip movement. For both instruments, an increasing MAI in the trapezius was observed as the string position became increasingly lateral, from string 1 (most medial) toward string 4 (most lateral). Half an hour of performance did not cause significant differences between the signal quality and the MAI values measured before and after the exercise. The MAI of the left and right erector spinae was smaller in the case of

Effects of platinum stagnation surface on the lean extinction limits of premixed methane/air flames at moderate surface temperatures

Energy Technology Data Exchange (ETDEWEB)

Wiswall, J.T.; Li, J.; Wooldridge, M.S.; Im, H.G. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI (United States)

2011-01-15

A stagnation flow reactor was used to study the effects of platinum on the lean flammability limits of atmospheric pressure premixed methane/air flames at moderate stagnation surface temperatures. Experimental and computational methods were used to quantify the equivalence ratio at the lean extinction limit ({phi}{sub ext}) and the corresponding stagnation surface temperature (T{sub s}). A range of flow rates (57-90 cm/s) and corresponding strain rates were considered. The results indicate that the gas-phase methane/air flames are sufficiently strong relative to the heterogeneous chemistry for T{sub s} conditions less than 750 K that the platinum does not affect {phi}{sub ext}. The computational results are in good agreement with the experimentally observed trends and further indicate that higher reactant flow rates (>139 cm/s) and levels of dilution (>{proportional_to}10% N{sub 2}) are required to weaken the gas-phase flame sufficiently for surface reaction to play a positive role on extending the lean flammability limits. (author)

On play and playing.

Science.gov (United States)

Rudan, Dusko

2013-12-01

The paper offers a review of the development of the concept of play and playing. The true beginnings of the development of the theories of play are set as late as in the 19th century. It is difficult to define play as such; it may much more easily be defined through its antipode--work. In the beginning, play used to be connected with education; it was not before Freud's theory of psychoanalysis and Piaget's developmental psychology that the importance of play in a child's development began to be explained in more detail. The paper further tackles the role of play in the adult age. Detailed attention is paid to psychodynamic and psychoanalytic authors, in particular D. W. Winnicott and his understanding of playing in the intermediary (transitional) empirical or experiential space. In other words, playing occupies a space and time of its own. The neuroscientific concept of playing is also tackled, in the connection with development as well.

Short-Term Effects of Playing Computer Games on Attention

Science.gov (United States)

Tahiroglu, Aysegul Yolga; Celik, Gonca Gul; Avci, Ayse; Seydaoglu, Gulsah; Uzel, Mehtap; Altunbas, Handan

2010-01-01

Objective: The main aim of the present study is to investigate the short-term cognitive effects of computer games in children with different psychiatric disorders and normal controls. Method: One hundred one children are recruited for the study (aged between 9 and 12 years). All participants played a motor-racing game on the computer for 1 hour.…

[Play therapy--psychotherapy with play as the medium: II. New developments].

Science.gov (United States)

von Gontard, Alexander; Lehmkuhl, Gerd

2003-02-01

A wide array of new forms and combinations of play therapy have been developed. The aim of the second part of this paper is to present an overview of these newer approaches, including: focussed therapies for specific disorders; behavioural approaches like the Cognitive-Behavioral Play Therapy and the Parent-Child Interaction Therapy; various combinations with family therapy; and therapies especially for preschool children like Filial Therapy, Developmental Play Therapy and Thera-play. Following a phase of experiments and combinations, the empirical evaluation of many play-therapy forms is needed. Especially questions of the differential indication of specific play-therapies and their effectiveness in the therapeutical practice need to be studied.

Surface effects in metal oxide-based nanodevices

KAUST Repository

Lien, Der Hsien; Duran Retamal, Jose Ramon; Ke, Jr Jian; Kang, Chen Fang; He, Jr-Hau

2015-01-01

As devices shrink to the nanoscale, surface-to-volume ratio increases and the surface-environment interaction becomes a major factor for affecting device performance. The variation of electronic properties, including the surface band bending, gas chemisorption or photodesorption, native surface defects, and surface roughness, is called "surface effects". Such effects are ambiguous because they can be either negative or beneficial effects, depending on the environmental conditions and device application. This review provides an introduction to the surface effects on different types of nanodevices, offering the solutions to respond to their benefits and negative effects and provides an outlook on further applications regarding the surface effect. This review is beneficial for designing nano-enabled photodetectors, harsh electronics, memories, sensors and transistors via surface engineering.

Surface effects in metal oxide-based nanodevices

KAUST Repository

Lien, Der Hsien

2015-10-29

As devices shrink to the nanoscale, surface-to-volume ratio increases and the surface-environment interaction becomes a major factor for affecting device performance. The variation of electronic properties, including the surface band bending, gas chemisorption or photodesorption, native surface defects, and surface roughness, is called "surface effects". Such effects are ambiguous because they can be either negative or beneficial effects, depending on the environmental conditions and device application. This review provides an introduction to the surface effects on different types of nanodevices, offering the solutions to respond to their benefits and negative effects and provides an outlook on further applications regarding the surface effect. This review is beneficial for designing nano-enabled photodetectors, harsh electronics, memories, sensors and transistors via surface engineering.

Surface Effects in Magnetic Nanoparticles

CERN Document Server

Fiorani, Dino

2005-01-01

This volume is a collection of articles on different approaches to the investigation of surface effects on nanosized magnetic materials, with special emphasis on magnetic nanoparticles. The book aims to provide an overview of progress in the understanding of surface properties and surface driven effects in magnetic nanoparticles through recent results of different modeling, simulation, and experimental investigations.

Surface effect theory in binary alloys: surfaces with cut-off

International Nuclear Information System (INIS)

Kumar, V.; Silva, C.E.T.G. da; Moran-Lopez, J.L.

1981-01-01

A surface effect theory in binary alloys which ore ordered with surfaces with cut-off is presented. This theory is based in a model of pair interaction between first neighbours and includes long and short range effects. The (120) surface with sup(-) (110) monoatomic cut-off and terrace in the (110) planes of an alloy with body centered cubic structure is presented as example. Results for the concentrations in all the different surface sites are given. (L.C.) [pt

Effect of playing violent video games cooperatively or competitively on subsequent cooperative behavior.

Science.gov (United States)

Ewoldsen, David R; Eno, Cassie A; Okdie, Bradley M; Velez, John A; Guadagno, Rosanna E; DeCoster, Jamie

2012-05-01

Research on video games has yielded consistent findings that violent video games increase aggression and decrease prosocial behavior. However, these studies typically examined single-player games. Of interest is the effect of cooperative play in a violent video game on subsequent cooperative or competitive behavior. Participants played Halo II (a first-person shooter game) cooperatively or competitively and then completed a modified prisoner's dilemma task to assess competitive and cooperative behavior. Compared with the competitive play conditions, players in the cooperative condition engaged in more tit-for-tat behaviors-a pattern of behavior that typically precedes cooperative behavior. The social context of game play influenced subsequent behavior more than the content of the game that was played.

Relative Effectiveness of Operant Conditioning and Play Therapy in Childhood Schizophrenia

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Ney, Philip G.; And Others

1971-01-01

An experimental study designed to examine the relative effectiveness of operant conditioning and play therapy in improving the communication and social functioning of psychotic children was presented and discussed. (Author)

Effect of Partner's Gender on Early Pretend Play: A Preliminary Study of Singapore Chinese Preschoolers

Science.gov (United States)

Jing, Mengguo; Li, Hui

2015-01-01

This study examined the developmental trend of pretend play behaviour and the effect of partner's gender in Singaporean preschoolers. Peer dyadic play among 70 children, ranging in age from three to five years, was observed in a standardised toy play context. Videotaped recordings of the play were analysed using two scales--the Smilansky Scale for…

Effects of passion for massively multiplayer online role-playing games on interpersonal relationships

NARCIS (Netherlands)

Utz, S.; Jonas, K.J.; Tonkens, E.

2012-01-01

Game research suffers from using a variety of concepts to predict the (often negative) effects of playing games. These concepts often overlap (e.g., addiction or pathological gaming), include negative consequences in their definition, or are very game-specific (e.g., collective play). We argue that

Surface diffusion of long chainlike molecules: The role of memory effects and stiffness on effective diffusion barriers

DEFF Research Database (Denmark)

Hjelt, T.; Vattulainen, Ilpo Tapio

2000-01-01

stiffness. Our primary aim is to consider the role played by chain stiffness and the resulting memory effects in tracer diffusion, and in particular their role in the effective tracer diffusion barrier E-A(T) extracted from the well-known Arrhenius form. We show that the memory effects in tracer diffusion......, for a single diffusing chain, about 20% of E-A(T) arises from temperature variations in the memory effects, while only the remaining part comes from thermally activated chain segment movements. At a finite coverage, the memory contribution in E-A(T) is even larger and is typically about 20%-40%. Further...... of recent experimental work as regards surface diffusion of long DNA molecules on a biological interface. (C) 2000 American Institute of Physics....

The effect of presleep video-game playing on adolescent sleep.

Science.gov (United States)

Weaver, Edward; Gradisar, Michael; Dohnt, Hayley; Lovato, Nicole; Douglas, Paul

2010-04-15

Video-game use before bedtime has been linked with poor sleep outcomes for adolescents; however, experimental evidence to support this link is sparse. The present study investigated the capacity of presleep video-game playing to extend sleep latency and reduce subjective feelings of sleepiness in adolescents. The arousing psychophysiologic mechanisms involved and the impact of presleep video-game playing on sleep architecture were also explored. Thirteen male adolescent "evening types" (mean age = 16.6 years, SD = 1.1) participated in a counterbalanced, within-subjects design with experimental (active video gaming) and control (passive DVD watching) conditions. The experiment was conducted in the Flinders University Sleep Research Laboratory. Relative to the control condition, presleep video-game playing increased sleep-onset latency (Z= 2.45, p= .01) and reduced subjective sleepiness (Z = 2.36, p = .02)-but only slightly. Video gaming was related to changes in cognitive alertness (as measured by a power: p 0.05). Contrary to previous findings, sleep architecture was unaffected (both rapid eye movement and slow wave sleep: p > 0.05). Results suggest the direct effect of presleep video-game playing on adolescent sleep may be more modest than previously thought, suggesting that surveys linking stimulating presleep activities to poor sleep need substantiating with empirical evidence.

Effects of Playing versus Observing Violent versus Nonviolent Video Games on Children's Aggression.

Science.gov (United States)

Graybill, Daniel; And Others

1987-01-01

Examined short-term effects of playing versus observing violent versus nonviolent video games on the aggression of elementary school children. Children (N=146) played or observed games for 14 minutes, then completed three measures of aggression. Found no differences between violent and nonviolent conditions on measures of aggression. (Author/NB)

Play, Playfulness, Creativity and Innovation

Directory of Open Access Journals (Sweden)

Patrick Bateson

2014-05-01

Full Text Available Play, as defined by biologists and psychologists, is probably heterogeneous. On the other hand, playfulness may be a unitary motivational state. Playful play as opposed to activities that merge into aggression is characterized by positive mood, intrinsic motivation, occurring in a protected context and easily disrupted by stress. Playful play is a good measure of positive welfare. It can occupy a substantial part of the waking-life of a young mammal or bird. Numerous functions for play have been proposed and they are by no means mutually exclusive, but some evidence indicates that those individual animals that play most are most likely to survive and reproduce. The link of playful play to creativity and hence to innovation in humans is strong. Considerable evidence suggests that coming up with new ideas requires a different mindset from usefully implementing a new idea.

Surface effects of underground nuclear explosions

Energy Technology Data Exchange (ETDEWEB)

Allen, B.M.; Drellack, S.L. Jr.; Townsend, M.J.

1997-06-01

The effects of nuclear explosions have been observed and studied since the first nuclear test (code named Trinity) on July 16, 1945. Since that first detonation, 1,053 nuclear tests have been conducted by the US, most of which were sited underground at the Nevada Test Site (NTS). The effects of underground nuclear explosions (UNEs) on their surroundings have long been the object of much interest and study, especially for containment, engineering, and treaty verification purposes. One aspect of these explosion-induced phenomena is the disruption or alteration of the near-surface environment, also known as surface effects. This report was prepared at the request of the Los Alamos National Laboratory (LANL), to bring together, correlate, and preserve information and techniques used in the recognition and documentation of surface effects of UNEs. This report has several main sections, including pertinent background information (Section 2.0), descriptions of the different types of surface effects (Section 3.0), discussion of their application and limitations (Section 4.0), an extensive bibliography and glossary (Section 6.0 and Appendix A), and procedures used to document geologic surface effects at the NTS (Appendix C). Because a majority of US surface-effects experience is from the NTS, an overview of pertinent NTS-specific information also is provided in Appendix B. It is not within the scope of this report to explore new relationships among test parameters, physiographic setting, and the types or degree of manifestation of surface effects, but rather to compile, summarize, and capture surface-effects observations and interpretations, as well as documentation procedures and the rationale behind them.

A numerical investigation of the effect of surface wettability on the boiling curve.

Directory of Open Access Journals (Sweden)

Hua-Yi Hsu

Full Text Available Surface wettability is recognized as playing an important role in pool boiling and the corresponding heat transfer curve. In this work, a systematic study of pool boiling heat transfer on smooth surfaces of varying wettability (contact angle range of 5° - 180° has been conducted and reported. Based on numerical simulations, boiling curves are calculated and boiling dynamics in each regime are studied using a volume-of-fluid method with contact angle model. The calculated trends in critical heat flux and Leidenfrost point as functions of surface wettability are obtained and compared with prior experimental and theoretical predictions, giving good agreement. For the first time, the effect of contact angle on the complete boiling curve is shown. It is demonstrated that the simulation methodology can be used for studying pool boiling and related dynamics and providing more physical insights.

Teaching to Play Performing a Main Role -- Effective Method of Pretend Play Facilitation in Preschool-Age Children

Science.gov (United States)

Gmitrova, Vlasta

2013-01-01

We compared the efficiency of teacher's direct and indirect intervention into pretend play. Three hundred sixty-eight kindergarten children and 92 qualified kindergarten teachers were involved in the study. In the control group, a teacher indirectly initiated a play, creating a playing corner adjusted to the theme of the pretend play and during…

Surface modification effects of fluorine-doped tin dioxide by oxygen plasma ion implantation

Science.gov (United States)

Tang, Peng; Liu, Cai; Zhang, Jingquan; Wu, Lili; Li, Wei; Feng, Lianghuan; Zeng, Guanggen; Wang, Wenwu

2018-04-01

SnO2:F (FTO), as a kind of transparent conductive oxide (TCO), exhibits excellent transmittance and conductivity and is widely used as transparency electrodes in solar cells. It's very important to modifying the surface of FTO for it plays a critical role in CdTe solar cells. In this study, modifying effects of oxygen plasma on FTO was investigated systematically. Oxygen plasma treatment on FTO surface with ion accelerating voltage ranged from 0.4 kV to 1.6 kV has been processed. The O proportion of surface was increased after ion implantation. The Fermi level of surface measurement by XPS valance band spectra was lowered as the ion accelerating voltage increased to 1.2 kV and then raised as accelerating voltage was elevated to 1.6 kV. The work function measured by Kelvin probe force microscopy increased after ion implanting, and it was consistent with the variation of Fermi level. The change of energy band structure of FTO surface mainly originated from the surface composition variation. As FTO conduction was primarily due to oxyanion hole, the carrier was electron and its concentration was reduced while O proportion was elevated at the surface of FTO, as a result, the Fermi level lowered and the work function was enlarged. It was proved that oxygen plasma treatment is an effective method to modulate the energy band structure of the surface as well as other properties of FTO, which provides much more space for interface and surface modification and then photoelectric device performance promotion.

The effects of hard particles on the surface quality when micro-cutting aluminum 6061 T6

International Nuclear Information System (INIS)

Ding, X; Lee, L C; Butler, D L; Cheng, C K

2009-01-01

Studies of micro-cutting have so far largely been carried out on single-phase materials. Due to the size effect, the workpiece material microstructure can have a significant influence on the cutting force, chip formation and surface quality. Previous investigations have shown that hard particles in materials such as aluminum alloy can play a significant role in the generation of defects such as cracks and voids on the work surface. This paper will examine the extent of the problem during the micro-cutting of Al6061 T6 and propose how it can be mitigated

Surface Rupture Effects on Earthquake Moment-Area Scaling Relations

Science.gov (United States)

Luo, Yingdi; Ampuero, Jean-Paul; Miyakoshi, Ken; Irikura, Kojiro

2017-09-01

Empirical earthquake scaling relations play a central role in fundamental studies of earthquake physics and in current practice of earthquake hazard assessment, and are being refined by advances in earthquake source analysis. A scaling relation between seismic moment ( M 0) and rupture area ( A) currently in use for ground motion prediction in Japan features a transition regime of the form M 0- A 2, between the well-recognized small (self-similar) and very large (W-model) earthquake regimes, which has counter-intuitive attributes and uncertain theoretical underpinnings. Here, we investigate the mechanical origin of this transition regime via earthquake cycle simulations, analytical dislocation models and numerical crack models on strike-slip faults. We find that, even if stress drop is assumed constant, the properties of the transition regime are controlled by surface rupture effects, comprising an effective rupture elongation along-dip due to a mirror effect and systematic changes of the shape factor relating slip to stress drop. Based on this physical insight, we propose a simplified formula to account for these effects in M 0- A scaling relations for strike-slip earthquakes.

Effects of wood fiber surface chemistry on strength of wood–plastic composites

Energy Technology Data Exchange (ETDEWEB)

Migneault, Sébastien, E-mail: sebastien.migneault@uqat.ca [University of Quebec in Abitibi-Temiscamingue (UQAT), 445 boulevard de l’Université, Rouyn-Noranda, Québec J9X 5E4 (Canada); Koubaa, Ahmed, E-mail: ahmed.koubaa@uqat.ca [UQAT (Canada); Perré, Patrick, E-mail: patrick.perre@ecp.fr [École centrale de Paris, Grande Voie des Vignes, F-92 295 Chatenay-Malabry Cedex (France); Riedl, Bernard, E-mail: Bernard.Riedl@sbf.ulaval.ca [Université Laval, 2425 rue de la Terrasse, Québec City, Québec G1V 0A6 (Canada)

2015-07-15

Highlights: • Infrared spectroscopy and X-ray photoelectron spectroscopy analyses showed variations of surface chemical characteristics according to fiber origin. • Surface chemical characteristics of fibers could partly explain the differences in mechanical properties of the wood–plastic composites. • Fibers with carbohydrate rich surface led to stronger wood–plastic composites because the coupling between the matrix and fibers using coupling agent is achieved with polar sites mostly available on carbohydrates. • Conversely, lignin or extractives rich surface do not have oxidized functions for the esterification reaction with coupling agent and thus led to wood–plastic composites with lower mechanical properties. • Other factors such as mechanical interlocking and fiber morphology interfere with the effects of fiber surface chemistry. - Abstract: Because wood–plastic composites (WPC) strength relies on fiber-matrix interaction at fiber surface, it is likely that fiber surface chemistry plays an important role in WPC strength development. The objective of the present study is to investigate the relationships between fiber surface chemical characteristics and WPC mechanical properties. Different fibers were selected and characterized for surface chemical characteristics using X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR). WPC samples were manufactured at 40% fiber content and with six different fibers. High density polyethylene was used as matrix and maleated polyethylene (MAPE) was used as compatibility agent. WPC samples were tested for mechanical properties and fiber-matrix interface was observed with scanning electron microscope. It was found WPC strength decreases as the amount of unoxidized carbon (assigned to lignin and extractives) measured with XPS on fiber surface increases. In the opposite case, WPC strength increases with increasing level of oxidized carbon (assigned to carbohydrates) on fiber surface. The same

Effects of wood fiber surface chemistry on strength of wood–plastic composites

International Nuclear Information System (INIS)

Migneault, Sébastien; Koubaa, Ahmed; Perré, Patrick; Riedl, Bernard

2015-01-01

Highlights: • Infrared spectroscopy and X-ray photoelectron spectroscopy analyses showed variations of surface chemical characteristics according to fiber origin. • Surface chemical characteristics of fibers could partly explain the differences in mechanical properties of the wood–plastic composites. • Fibers with carbohydrate rich surface led to stronger wood–plastic composites because the coupling between the matrix and fibers using coupling agent is achieved with polar sites mostly available on carbohydrates. • Conversely, lignin or extractives rich surface do not have oxidized functions for the esterification reaction with coupling agent and thus led to wood–plastic composites with lower mechanical properties. • Other factors such as mechanical interlocking and fiber morphology interfere with the effects of fiber surface chemistry. - Abstract: Because wood–plastic composites (WPC) strength relies on fiber-matrix interaction at fiber surface, it is likely that fiber surface chemistry plays an important role in WPC strength development. The objective of the present study is to investigate the relationships between fiber surface chemical characteristics and WPC mechanical properties. Different fibers were selected and characterized for surface chemical characteristics using X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR). WPC samples were manufactured at 40% fiber content and with six different fibers. High density polyethylene was used as matrix and maleated polyethylene (MAPE) was used as compatibility agent. WPC samples were tested for mechanical properties and fiber-matrix interface was observed with scanning electron microscope. It was found WPC strength decreases as the amount of unoxidized carbon (assigned to lignin and extractives) measured with XPS on fiber surface increases. In the opposite case, WPC strength increases with increasing level of oxidized carbon (assigned to carbohydrates) on fiber surface. The same

Effects of prenatal exposure to opioids on focused attention in toddlers during free play.

Science.gov (United States)

Schneider, J W; Hans, S L

1996-08-01

The goals of this study were: (1) to determine if 24-month-old children exposed to opioids show decreased focused attention during free play compared with children of the same age who were not prenatally exposed; (2) to identify medical and social risk factors other than drug exposure that are related to focused attention; and (3) to determine if mothers' teaching ability had an effect on attention. Focused attention was rated during a 3-minute free play session for 30 toddlers who were methadone-exposed and for 44 comparison toddlers. The mother teaching the child to use a toy was also rated separately from the free play session. There was no difference in focused attention of 24 month olds during free play based only on prenatal exposure. Despite group differences in medical and social risk factors, only maternal IQ was significantly related to focused attention. Maternal instruction was strongly related to focused attention and mediated the effects of maternal IQ on attention.

Interfacial slippage effect on the surface instability of a thin elastic film under van der Waals force

International Nuclear Information System (INIS)

Pan Xiahui; Yu Shouwen; Feng Xiqiao; Huang Shiqing

2009-01-01

This paper studies the surface instability of an elastic thin solid film lying on a rigid substrate and subjected to van der Waals-like surface interactions. The effect of film-substrate interfacial slippage is accounted for by using a simplified linear cohesive interface model. It is found that the interfacial slippage generally plays a destabilizing role in the surface instability of the thin film. For highly compressible films with Poisson's ratio smaller than 0.25, the surface wrinkling behaviour previously inconceivable in the case of a perfectly bonded interface is now feasible if film-substrate interface slipping is permitted. In addition, our linear perturbation analysis shows that the critical conditions for the onset of surface instability can be modulated by adjusting the slippery stiffness of the interface. The result might be helpful for developing novel techniques to create micro-/nanosized surface patterns.

Children's risky play from an evolutionary perspective: the anti-phobic effects of thrilling experiences.

Science.gov (United States)

Sandseter, Ellen Beate Hansen; Kennair, Leif Edward Ottesen

2011-06-21

This theoretical article views children's risky play from an evolutionary perspective, addressing specific evolutionary functions and especially the anti-phobic effects of risky play. According to the non-associative theory, a contemporary approach to the etiology of anxiety, children develop fears of certain stimuli (e.g., heights and strangers) that protect them from situations they are not mature enough to cope with, naturally through infancy. Risky play is a set of motivated behaviors that both provide the child with an exhilarating positive emotion and expose the child to the stimuli they previously have feared. As the child's coping skills improve, these situations and stimuli may be mastered and no longer be feared. Thus fear caused by maturational and age relevant natural inhibition is reduced as the child experiences a motivating thrilling activation, while learning to master age adequate challenges. It is concluded that risky play may have evolved due to this anti-phobic effect in normal child development, and it is suggested that we may observe an increased neuroticism or psychopathology in society if children are hindered from partaking in age adequate risky play.

Children's Risky Play from an Evolutionary Perspective: The Anti-Phobic Effects of Thrilling Experiences

Directory of Open Access Journals (Sweden)

Ellen Beate Hansen Sandseter

2011-04-01

Full Text Available This theoretical article views children's risky play from an evolutionary perspective, addressing specific evolutionary functions and especially the anti-phobic effects of risky play. According to the non-associative theory, a contemporary approach to the etiology of anxiety, children develop fears of certain stimuli (e.g., heights and strangers that protect them from situations they are not mature enough to cope with, naturally through infancy. Risky play is a set of motivated behaviors that both provide the child with an exhilarating positive emotion and expose the child to the stimuli they previously have feared. As the child's coping skills improve, these situations and stimuli may be mastered and no longer be feared. Thus fear caused by maturational and age relevant natural inhibition is reduced as the child experiences a motivating thrilling activation, while learning to master age adequate challenges. It is concluded that risky play may have evolved due to this anti-phobic effect in normal child development, and it is suggested that we may observe an increased neuroticism or psychopathology in society if children are hindered from partaking in age adequate risky play.

Effect of heat treatment on surface hydrophilicity-retaining ability of titanium dioxide nanotubes

Science.gov (United States)

Sun, Yu; Sun, Shupei; Liao, Xiaoming; Wen, Jiang; Yin, Guangfu; Pu, Ximing; Yao, Yadong; Huang, Zhongbing

2018-05-01

The aim of this study is to investigate the effect of different annealing temperature and atmosphere on the surface wettability retaining properties of titania nanotubes (TNs) fabricated by anodization. The TNs morphology, crystal phase composition and surface elemental composition and water contact angle (WCA) were investigated by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and contact angle instrument, respectively. After the samples annealed at 200 °C, 450 °C, 850 °C have been stored in air for 28 days, the WCAs increase to 31.7°, 21.1° and 110.5°, respectively. The results indicate that crystal phase composition of TNs plays an important role in surface wettability. Compared with the WCA (21.1°) of the samples annealed in air after 28 days, the WCA of samples annealed in oxygen-deficient atmosphere is lower, suggesting the contribution of oxygen vacancy in the enhanced hydrophilicity-retaining ability. Our study demonstrates that the surface hydrophilicity-retaining ability of TNs is related to the ordered nanotubular structure, crystal structure, the amount of surface hydroxyl group and oxygen vacancy defects.

Effect of Short- and Long-Term Play Therapy Services on Teacher-Child Relationship Stress

Science.gov (United States)

Ray, Dee C.; Henson, Robin K.; Schottelkorb, April A.; Brown, April Garofano; Muro, Joel

2008-01-01

The purpose of the present study was to explore the effect of both short- and long term Child-Centered Play Therapy on teacher-student relationship stress. Teachers identified 58 students exhibiting emotional and behavioral difficulties who were randomly assigned to one of two treatment groups. Students in the short-term intensive play therapy…

Play Practices and Play Moods

DEFF Research Database (Denmark)

Karoff, Helle Skovbjerg

2013-01-01

The aim of this article is to develop a view of play as a relation between play practices and play moods based on an empirical study of children's everyday life and by using Bateson's term of ‘framing’ [(1955/2001). In Steps to an ecology of mind (pp. 75–80). Chicago: University of Chicago Press......], Schmidt's notion of ‘commonness’ [(2005). Om respekten. København: Danmarks Pædagogiske Universitets Forlag; (2011). On respect. Copenhagen: Danish School of Education University Press] and Heidegger's term ‘mood’ [(1938/1996). Time and being. Cornwall: Wiley-Blackwell.]. Play mood is a state of being...... in which we are open and ready, both to others and their production of meaning and to new opportunities for producing meaning. This play mood is created when we engage with the world during play practices. The article points out four types of play moods – devotion, intensity, tension and euphorica – which...

Designing Out the Play: Accessibility and Playfulness in Inclusive Play.

Science.gov (United States)

Holt, Raymond; Beckett, Angharad

2017-01-01

Play is an important part of child development, yet disabled children are often excluded from the opportunity to play, either due to lack of accessible toys and games, or social pressures. This paper presents a case study reflecting on the development of Button Bash: a switch accessible game intended to encourage inclusive play between disabled and non-disabled children. In particular, the paper focuses on how changes intended to make the game more accessible tended to make it less playful, and reflects on the relationship between playfulness and accessibility.

Deliberate play and preparation jointly benefit motor and cognitive development: mediated and moderated effects

Directory of Open Access Journals (Sweden)

Caterina ePesce

2016-03-01

Full Text Available In light of the interrelation between motor and cognitive development and the predictive value of the former for the latter, the secular decline observed in motor coordination ability as early as preschool urges identification of interventions that may jointly impact motor and cognitive efficiency.The aim of this study was twofold. It (1 explored the outcomes of enriched physical education, centered on deliberate play and cognitively challenging variability of practice, on motor coordination and cognitive processing; (2 examined whether motor coordination outcomes mediate intervention effects on children’s cognition, while controlling for moderation by lifestyle factors as outdoor play habits and weight status. Four hundred and sixty children aged 5-10 years participated in a 6-month group randomized intervention in physical education, with or without playful coordinative and cognitive enrichment. The weight status and spontaneous outdoor play habits of children (parental report of outdoor play were evaluated at baseline. Before and after the intervention, motor developmental level (Movement Assessment Battery for Children was evaluated in all children, who were then assessed either with a test of working memory (Random Number Generation task, or with a test of attention (from the Cognitive Assessment System, CAS.Children assigned to the ‘enriched’ intervention showed more pronounced improvements in all motor coordination assessments (manual dexterity, ball skills, static/dynamic balance. The beneficial effect on ball skills was amplified by the level of spontaneous outdoor play and weight status. Among indices of executive function and attention, only that of inhibition showed a differential effect of intervention type. Moderated mediation showed that the better outcome of the enriched physical education on ball skills mediated the better inhibition outcome, but only when the enrichment intervention was paralleled by a medium

A study on the effects of heated surface wettability on nucleation characteristics in subcooled flow boiling

International Nuclear Information System (INIS)

Kajihara, Tomoyuki; Kaiho, Kazuhiro; Okawa, Tomio

2014-01-01

Subcooled flow boiling plays an important role in boiling water reactors because it influences the heat transfer performance from fuel rods, two-phase flow stabilities, and neutron moderation characteristics. In the present study, flow visualization of water subcooled flow boiling in a vertical heated channel was carried out to investigate the mechanisms of void fraction development. The two surfaces of distinctly different contact angles were used as the heated surface to investigate the effect of the surface wettability. It was observed that with an increase in the wall heat flux, more nucleation sites were activated and larger bubbles were produced at low-frequency. It was considered that formation of these large bubbles primarily contributed to the void fraction development. (author)

Pleasure to play, arousal to stay: the effect of player emotions on digital game preferences and playing time.

Science.gov (United States)

Poels, Karolien; van den Hoogen, Wouter; Ijsselsteijn, Wijnand; de Kort, Yvonne

2012-01-01

This study investigated how player emotions during game-play, measured through self-report and physiological recordings, predict playing time and game preferences. We distinguished between short-term (immediately after game-play) and long-term (after 3 weeks) playing time and game preferences. While pleasure was most predictive for short-term playing time and game preferences, arousal, particularly for game preferences, was most predictive on the longer term. This result was found through both self-report and physiological emotion measures. This study initiates theorizing about digital gaming as a hedonic consumer product and sketches future research endeavors of this topic.

Biofilm Surface Density Determines Biocide Effectiveness

Directory of Open Access Journals (Sweden)

Sara Bas

2017-12-01

Full Text Available High resistance of biofilms for chemical challenges is a serious industrial and medical problem. In this work a gradient of surface covered with biofilm has been produced and correlated to the effectiveness of different commercially available oxidative biocides. The results for thin Escherichia coli biofilms grown in rich media supplemented with glucose or lactose on glass or poly methyl methacrylate surfaces indicate that the effectiveness of hydrogen peroxide or chlorine dioxide and quaternary ammonium compounds is inversely proportional to the fraction of the surface covered with the biofilm. In areas where biofilm covered more than 90% of the available surface the biocide treatment was inefficient after 60 min of incubation. The combined effect of oxidant and surfactant increased the effectiveness of the biocide. On the other hand, the increased biofilm viscoelasticity reduced biocide effectiveness. The results emphasize differential biocide effectiveness depending on the fraction of the attached bacterial cells. The results suggest that biofilm biocide resistance is an acquired property that increases with biofilm maturation. The more dense sessile structures present lower log reductions compared to less dense ones.

The effect of physiological conditions on the surface structure of proteins: Setting the scene for human digestion of emulsions

Science.gov (United States)

Maldonado-Valderrama, J.; Gunning, A. P.; Ridout, M. J.; Wilde, P. J.; Morris, V. J.

2009-10-01

Understanding and manipulating the interfacial mechanisms that control human digestion of food emulsions is a crucial step towards improved control of dietary intake. This article reports initial studies on the effects of the physiological conditions within the stomach on the properties of the film formed by the milk protein ( β -lactoglobulin) at the air-water interface. Atomic force microscopy (AFM), surface tension and surface rheology techniques were used to visualize and examine the effect of gastric conditions on the network structure. The effects of changes in temperature, pH and ionic strength on a pre-formed interfacial structure were characterized in order to simulate the actual digestion process. Changes in ionic strength had little effect on the surface properties. In isolation, acidification reduced both the dilatational and the surface shear modulus, mainly due to strong repulsive electrostatic interactions within the surface layer and raising the temperature to body temperature accelerated the rearrangements within the surface layer, resulting in a decrease of the dilatational response and an increase of surface pressure. Together pH and temperature display an unexpected synergism, independent of the ionic strength. Thus, exposure of a pre-formed interfacial β -lactoglobulin film to simulated gastric conditions reduced the surface dilatational modulus and surface shear moduli. This is attributed to a weakening of the surface network in which the surface rearrangements of the protein prior to exposure to gastric conditions might play a crucial role.

Effect of Play Therapy Applications on Shyness Behaviors of Pre-school Children

Directory of Open Access Journals (Sweden)

Selda Kockaya

2017-03-01

Full Text Available The purpose of this research is to examine the impact of play therapy on a child who have shyness behavior through parent and teacher evaluations in preschool. The research was carried out with the participation of one shy student from six age groups who has been registered at 2014-2015 academic year in Saraykoy Central Mukerrem Tokat Kindergarten in Saraykoy, Denizli. AB experimental design was used from single subject design in the study. When results of the research examined, according to child's mother and teacher, play therapy intervention reduced emotional problems and peer relation problems and caused increase in prosocial behaviors. It could be said that play therapy program might have effective and significant impact on preschool children who have shyness behavior. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2017; 9(1.000: 31-44

Experimental study of the differential effects of playing versus watching violent video games on children's aggressive behavior.

Science.gov (United States)

Polman, Hanneke; de Castro, Bram Orobio; van Aken, Marcel A G

2008-01-01

There is great concern about the effects of playing violent video games on aggressive behavior. The present experimental study was aimed at investigating the differential effects of actively playing vs. passively watching the same violent video game on subsequent aggressive behavior. Fifty-seven children aged 10-13 either played a violent video game (active violent condition), watched the same violent video game (passive violent condition), or played a non-violent video game (active non-violent condition). Aggression was measured through peer nominations of real-life aggressive incidents during a free play session at school. After the active participation of actually playing the violent video game, boys behaved more aggressively than did the boys in the passive game condition. For girls, game condition was not related to aggression. These findings indicate that, specifically for boys, playing a violent video game should lead to more aggression than watching television violence. Copyright 2007 Wiley-Liss, Inc.

The effects of video game playing on attention, memory, and executive control.

Science.gov (United States)

Boot, Walter R; Kramer, Arthur F; Simons, Daniel J; Fabiani, Monica; Gratton, Gabriele

2008-11-01

Expert video game players often outperform non-players on measures of basic attention and performance. Such differences might result from exposure to video games or they might reflect other group differences between those people who do or do not play video games. Recent research has suggested a causal relationship between playing action video games and improvements in a variety of visual and attentional skills (e.g., [Green, C. S., & Bavelier, D. (2003). Action video game modifies visual selective attention. Nature, 423, 534-537]). The current research sought to replicate and extend these results by examining both expert/non-gamer differences and the effects of video game playing on tasks tapping a wider range of cognitive abilities, including attention, memory, and executive control. Non-gamers played 20+ h of an action video game, a puzzle game, or a real-time strategy game. Expert gamers and non-gamers differed on a number of basic cognitive skills: experts could track objects moving at greater speeds, better detected changes to objects stored in visual short-term memory, switched more quickly from one task to another, and mentally rotated objects more efficiently. Strikingly, extensive video game practice did not substantially enhance performance for non-gamers on most cognitive tasks, although they did improve somewhat in mental rotation performance. Our results suggest that at least some differences between video game experts and non-gamers in basic cognitive performance result either from far more extensive video game experience or from pre-existing group differences in abilities that result in a self-selection effect.

Effects of Static Stretching and Playing Soccer on Knee Laxity.

Science.gov (United States)

Baumgart, Christian; Gokeler, Alli; Donath, Lars; Hoppe, Matthias W; Freiwald, Jürgen

2015-11-01

This study investigated exercise-induced effects of static stretching and playing soccer on anterior tibial translation (ATT) of the knee joint. Randomized controlled trial. University biomechanics laboratory. Thirty-one athletes were randomly assigned into a stretching (26.9 ± 6.2 years, 1.77 ± 0.09 m, 67.9 ± 10.7 kg) and a control group (27.9 ± 7.4 years, 1.75 ± 0.08 m, 72.0 ± 14.9 kg). Thirty-one amateur soccer players in an additional soccer group (25.1 ± 5.6 years, 1.74 ± 0.10 m, 71.8 ± 14.8 kg). All participants had no history of knee injury requiring surgery and any previous knee ligament or cartilage injury. The stretching group performed 4 different static stretching exercises with a duration of 2 × 20 seconds interspersed with breaks of 10 seconds. The soccer group completed a 90-minute soccer-specific training program. The control group did not perform any physical activity for approximately 30 minutes. Anterior tibial translation was measured with the KT-1000 knee arthrometer at forces of 67 N, 89 N, and maximal manual force (Max) before and after the intervention. There was a significant increase in ATT after static stretching and playing soccer at all applied forces. Maximal manual testing revealed a mean increase of ATT after static stretching of 2.1 ± 1.6 mm (P soccer of 1.0 ± 1.5 mm (P = 0.001). The ATT increase after static stretching at 67 and 89 N is significantly higher than in controls. At maximum manual testing, significant differences were evident between all groups. Static stretching and playing soccer increase ATT and may consequently influence mechanical factors of the anterior cruciate ligament. The ATT increase after static stretching was greater than after playing soccer. The observed increase in ATT after static stretching and playing soccer may be associated with changes in kinesthetic perception and sensorimotor control, activation of muscles, joint stability, overall performance, and higher injury risk.

Teachers and Parents Play to Learn: Play-Based Instruction in Computer Technology

Science.gov (United States)

Parker, Denise

2010-01-01

Play is so important that it is declared as one of the human rights by the United Nations. Although it is focused on children, play does "not" stop there. In the 1990s the author designed and facilitated a blended curriculum for a Head Start Program. The instructional goal was to introduce and get the children to effectively and…

Learning by Doing in Leadership Education: Experiencing Followership and Effective Leadership Communication through Role-Play

Science.gov (United States)

Tabak, Filiz; Lebron, Mariana

2017-01-01

This paper describes the implementation of a role-play exercise to illustrate the influence of followership styles and effective communication on leader-follower relationship formation and development. We provide the pedagogical theory and evidence behind using role-plays in classroom settings, followed by a literature review pertaining to…

Effect of Reaction Conditions on the Surface Modification of Cellulose Nanofibrils with Aminopropyl Triethoxysilane

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Eduardo Robles

2018-04-01

Full Text Available Nine different surface modifications of cellulose nanofibrils (CNF with 3-aminopropyl triethoxysilane (ATS by using three different solvent systems (water, ethanol, and a mixture of both were investigated. The effect of reaction conditions, such as silane to cellulose ratio and solvent type were evaluated to determine their contribution to the extent of the silane modification. Nanofibril properties were evaluated by infrared spectroscopy, powder X-ray diffraction, surface free energy, thermogravimetry, 13C and 29Si nuclear magnetic resonance, and electronic microscopy. The influence of the solvent in the solvolysis of the silane was reflected in the presence or absence of ethoxy groups in the silane. On the other hand, whereas the surface modification was increased directly proportionally to silane ratio on the reaction, the aggregation of nanofibrils was also increased, which can play a negative role in certain applications. The increment of silane modification also had substantial repercussions on the crystallinity of the nanofibrils by the addition of amorphous components to the crystalline unit; moreover, silane surface modifications enhanced the hydrophobic character of the nanofibrils.

Are the effects of Unreal violent video games pronounced when playing with a virtual reality system?

Science.gov (United States)

Arriaga, Patrícia; Esteves, Francisco; Carneiro, Paula; Monteiro, Maria Benedicta

2008-01-01

This study was conducted to analyze the short-term effects of violent electronic games, played with or without a virtual reality (VR) device, on the instigation of aggressive behavior. Physiological arousal (heart rate (HR)), priming of aggressive thoughts, and state hostility were also measured to test their possible mediation on the relationship between playing the violent game (VG) and aggression. The participants--148 undergraduate students--were randomly assigned to four treatment conditions: two groups played a violent computer game (Unreal Tournament), and the other two a non-violent game (Motocross Madness), half with a VR device and the remaining participants on the computer screen. In order to assess the game effects the following instruments were used: a BIOPAC System MP100 to measure HR, an Emotional Stroop task to analyze the priming of aggressive and fear thoughts, a self-report State Hostility Scale to measure hostility, and a competitive reaction-time task to assess aggressive behavior. The main results indicated that the violent computer game had effects on state hostility and aggression. Although no significant mediation effect could be detected, regression analyses showed an indirect effect of state hostility between playing a VG and aggression. Copyright 2008 Wiley-Liss, Inc.

Effect of Sex and Body Mass Index on Children's Physical Activity Intensity during Free Play at an Indoor Soft Play Center: An Exploratory Study.

Science.gov (United States)

Jones, Michelle A

2017-09-12

Background : Indoor soft play can provide a safe but exciting physical activity opportunity regardless of environmental conditions. Relatively little is known about the quality or quantity of physical activity engaged in by children during indoor free soft play. The aim of this study was to evaluate the contribution indoor free soft play can make in enabling children to meet physical activity guidelines and to evaluate the effects of sex and body mass index category. Methods : Seventy-two boys and girls aged five to 10 years engaged in un-controlled indoor free soft play with a mean duration of 120.7 (27.1) min, during which physical activity was monitored using Actigraph accelerometers. Results : Children spent an average of 61.7 (24.2) min engaging in moderate to vigorous physical activity (MVPA) and 51.4% ( n = 37) achieved the recommended 60 min of MVPA through the single visit to the indoor soft play center. Boys (68.3 (25.7) min) engaged in significantly ( p < 0.05) more MVPA than girls (55.8 (21.4) min). Normal weight (65.7 (23.3) min) children engaged in significantly more MVPA than overweight children (48.0 (18.9) min). Conclusions : Attendance at a soft play indoor center has the potential to support children to engage in sufficient MVPA and overcome environmental factors that can restrict physical activity opportunities.

Effects of black carbon and boundary layer interaction on surface ozone in Nanjing, China

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J. Gao

2018-05-01

Full Text Available As an important solar radiation absorbing aerosol, the effect of black carbon (BC on surface ozone, via reducing photolysis rate, has been widely discussed by offline model studies. However, BC–boundary layer (BL interactions also influence surface ozone. Using the online model simulations and process analysis, we demonstrate the significant impact of BC–BL interaction on surface ozone in Nanjing. The absorbing effect of BC heats the air above the BL and suppresses and delays the development of the BL, which eventually leads to a change in surface ozone via a change in the contributions from chemical and physical processes (photochemistry, vertical mixing and advection. For chemical processes, the suppression of the BL leads to large amounts of ozone precursors being confined below the BL which has an increased effect on ozone chemical production and offsets the decrease caused by the reduction of the photolysis rate, thus enhancing ozone chemical formation from 10:00 to 12:00 LT. Furthermore, changes in physical processes, especially the vertical mixing process, show a more significant influence on surface ozone. The weakened turbulence, caused by the suppressed BL, entrains much less ozone aloft down to the surface. Finally, summing-up the changes in the processes, surface ozone reduces before noon and the maximum reduction reaches 16.4 ppb at 12:00 LT. In the afternoon, the changes in chemical process are small which inconspicuously influence surface ozone. However, change in the vertical mixing process still influences surface ozone significantly. Due to the delayed development of the BL, there are obvious ozone gradients around the top of BL. Therefore, high concentrations of ozone aloft can still be entrained down to the surface which offsets the reduction of surface ozone. Comparing the changes in the processes, the change in vertical mixing plays the most important role in impacting surface ozone. Our results highlight the

Effects of black carbon and boundary layer interaction on surface ozone in Nanjing, China

Science.gov (United States)

Gao, Jinhui; Zhu, Bin; Xiao, Hui; Kang, Hanqing; Pan, Chen; Wang, Dongdong; Wang, Honglei

2018-05-01

As an important solar radiation absorbing aerosol, the effect of black carbon (BC) on surface ozone, via reducing photolysis rate, has been widely discussed by offline model studies. However, BC-boundary layer (BL) interactions also influence surface ozone. Using the online model simulations and process analysis, we demonstrate the significant impact of BC-BL interaction on surface ozone in Nanjing. The absorbing effect of BC heats the air above the BL and suppresses and delays the development of the BL, which eventually leads to a change in surface ozone via a change in the contributions from chemical and physical processes (photochemistry, vertical mixing and advection). For chemical processes, the suppression of the BL leads to large amounts of ozone precursors being confined below the BL which has an increased effect on ozone chemical production and offsets the decrease caused by the reduction of the photolysis rate, thus enhancing ozone chemical formation from 10:00 to 12:00 LT. Furthermore, changes in physical processes, especially the vertical mixing process, show a more significant influence on surface ozone. The weakened turbulence, caused by the suppressed BL, entrains much less ozone aloft down to the surface. Finally, summing-up the changes in the processes, surface ozone reduces before noon and the maximum reduction reaches 16.4 ppb at 12:00 LT. In the afternoon, the changes in chemical process are small which inconspicuously influence surface ozone. However, change in the vertical mixing process still influences surface ozone significantly. Due to the delayed development of the BL, there are obvious ozone gradients around the top of BL. Therefore, high concentrations of ozone aloft can still be entrained down to the surface which offsets the reduction of surface ozone. Comparing the changes in the processes, the change in vertical mixing plays the most important role in impacting surface ozone. Our results highlight the great impacts BC

Entropic and Electrostatic Effects on the Folding Free Energy of a Surface-Attached Biomolecule: An Experimental and Theoretical Study

Science.gov (United States)

Watkins, Herschel M.; Vallée-Bélisle, Alexis; Ricci, Francesco; Makarov, Dmitrii E.; Plaxco, Kevin W.

2012-01-01

Surface-tethered biomolecules play key roles in many biological processes and biotechnologies. However, while the physical consequences of such surface attachment have seen significant theoretical study, to date this issue has seen relatively little experimental investigation. In response we present here a quantitative experimental and theoretical study of the extent to which attachment to a charged –but otherwise apparently inert– surface alters the folding free energy of a simple biomolecule. Specifically, we have measured the folding free energy of a DNA stem loop both in solution and when site-specifically attached to a negatively charged, hydroxyl-alkane-coated gold surface. We find that, whereas surface attachment is destabilizing at low ionic strength it becomes stabilizing at ionic strengths above ~130 mM. This behavior presumably reflects two competing mechanisms: excluded volume effects, which stabilize the folded conformation by reducing the entropy of the unfolded state, and electrostatics, which, at lower ionic strengths, destabilizes the more compact folded state via repulsion from the negatively charged surface. To test this hypothesis we have employed existing theories of the electrostatics of surface-bound polyelectrolytes and the entropy of surface-bound polymers to model both effects. Despite lacking any fitted parameters, these theoretical models quantitatively fit our experimental results, suggesting that, for this system, current knowledge of both surface electrostatics and excluded volume effects is reasonably complete and accurate. PMID:22239220

Effects of Playing Violent versus Nonviolent Video Games on the Aggressive Ideation of Aggressive and Nonaggressive Children.

Science.gov (United States)

Graybill, Daniel; And Others

1985-01-01

Examines effects of playing violent and nonviolent video games on children's aggressive ideation. Children played a violent or nonviolent video game for eight minutes. Provides initial support, at least on a short-term basis, for notion that the playing of video games affects children's aggression fantasies. (Author/DST)

Spin Hall effect by surface roughness

KAUST Repository

Zhou, Lingjun

2015-01-08

The spin Hall and its inverse effects, driven by the spin orbit interaction, provide an interconversion mechanism between spin and charge currents. Since the spin Hall effect generates and manipulates spin current electrically, to achieve a large effect is becoming an important topic in both academia and industries. So far, materials with heavy elements carrying a strong spin orbit interaction, provide the only option. We propose here a new mechanism, using the surface roughness in ultrathin films, to enhance the spin Hall effect without heavy elements. Our analysis based on Cu and Al thin films suggests that surface roughness is capable of driving a spin Hall angle that is comparable to that in bulk Au. We also demonstrate that the spin Hall effect induced by surface roughness subscribes only to the side-jump contribution but not the skew scattering. The paradigm proposed in this paper provides the second, not if only, alternative to generate a sizable spin Hall effect.

Quantum interference in grazing scattering of swift He atoms from LiF(0 0 1) surfaces: Surface eikonal approximation

Energy Technology Data Exchange (ETDEWEB)

Gravielle, M.S. [Instituto de Astronomia y Fisica del Espacio, CONICET, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Dpto. de Fisica, FCEN, Universidad de Buenos Aires, Buenos Aires (Argentina)], E-mail: msilvia@iafe.uba.ar; Miraglia, J.E. [Instituto de Astronomia y Fisica del Espacio, CONICET, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Dpto. de Fisica, FCEN, Universidad de Buenos Aires, Buenos Aires (Argentina)

2009-02-15

This work deals with the interference effects recently observed in grazing collisions of few-keV atoms with insulator surfaces. The process is studied within a distorted-wave method, the surface eikonal approximation, based on the use of the eikonal wave function and involving axial channeled trajectories with different initial conditions. The theory is applied to helium atoms impinging on a LiF(0 0 1) surface along the <1 1 0> direction. The role played by the projectile polarization and the surface rumpling is investigated. We found that when both effects are included, the proposed eikonal approach provides angular projectile spectra in good agreement with the experimental findings.

Quantum interference in grazing scattering of swift He atoms from LiF(0 0 1) surfaces: Surface eikonal approximation

International Nuclear Information System (INIS)

Gravielle, M.S.; Miraglia, J.E.

2009-01-01

This work deals with the interference effects recently observed in grazing collisions of few-keV atoms with insulator surfaces. The process is studied within a distorted-wave method, the surface eikonal approximation, based on the use of the eikonal wave function and involving axial channeled trajectories with different initial conditions. The theory is applied to helium atoms impinging on a LiF(0 0 1) surface along the direction. The role played by the projectile polarization and the surface rumpling is investigated. We found that when both effects are included, the proposed eikonal approach provides angular projectile spectra in good agreement with the experimental findings.

Microseismic Monitoring Using Sparse Surface Network of Broadband Instruments: Western Canada Shale Play Case Study

Science.gov (United States)

Yenier, E.; Baturan, D.; Karimi, S.

2016-12-01

network and the use of broadband instrumentation. The results indicate that sparse surface networks of high quality instruments can provide rich and reliable datasets for evaluation of the impact and effectiveness of hydraulic fracture operations in regions with favorable surface noise, local stress and attenuation characteristics.

Play Therapy: Practice, Issues, and Trends

Science.gov (United States)

Homeyer, Linda E.; Morrison, Mary O.

2008-01-01

Play therapy is an effective means of responding to the mental health needs of young children and is widely accepted as a valuable and developmentally appropriate intervention. The authors discuss the importance of play in development, the therapeutic benefits of play, the rich history of play therapy, and recent research and current issues and…

Ion bombardment effect on surface state of metal

International Nuclear Information System (INIS)

Vaulin, E.P.; Georgieva, N.E.; Martynenko, T.P.

1990-01-01

The effect of slow argon ion bombardment on the surface microstructure of polycrystalline copper as well as the effect of surface state on sputtering of D-16 polycrystalline alloy are experimentally studied. Reduction of copper surface roughness is observed. It is shown that the D-16 alloy sputtering coefficient is sensitive to the surface state within the limits of the destructed surface layer

Guided play and free play in an enriched environment: Impact on motor development

Directory of Open Access Journals (Sweden)

Míriam Stock Palma

2014-06-01

Full Text Available The purpose of this study was to investigate the effects of guided play and free play in an enriched environmentintervention programs using motor skill development in kindergarten children. Seventy-one children attending kindergarten classes were assigned to two experimental groups and one control group. Participants performed the Test of Gross Motor Development-2 before and after the intervention period. Results revealed that both boys and girls in the guided play group showed motor skill improvement, whereas no changes were observed in motor development in the boys and girls assigned to the free play in enriched environment group, nor in those in the control group. These findings indicate that the teacher's role in the guided play intervention was crucial to help preschool children to improve their performance.

Flexible architecture: bamboo as a tool for children to play in urban kampung

Science.gov (United States)

Susanto, D.; Widyarko; Ilmiani, A. N.

2018-03-01

Due to the dense population and increase of development, urban kampung in Indonesia is facing a problem of limited children’s play spaces. Flexible architecture with its movable principle is expected to be a solution by creating children’s playing tool that is built among the dense urban kampung. Bamboo is the staple material because it is local, able to regenerate quickly, lightweight, and affordable. By using the exploratory method, this research tries to reveal the previously hidden aspects by evaluating all processes of design-build of three created children’s playing tools. These playing tools can be built in the kampung after three processes of apart-and-reassemble. However, there are several questions which need to be discussed further; the right configuration between the component and the joint of the bamboo, to make apart-and-reassemble process more effective in a dense urban kampung, and also how to make bamboo’s structure able to survive better under rainy seasons and surface humidity.

Effectiveness of Group Play Therapy on Symptoms of Oppositional Defiant Among Children

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Narges Morshed

2015-12-01

Full Text Available Background and Objectives: With regard to the prevalence of Oppositional-Defiant Disorder in children and converting to the other disorders, if left untreated, this research aims to investigate the effectiveness of group play therapy on oppositional-defiant disorder symptoms among children. Materials and Methods: This study is interventional and quasi-experimental research. In this study based on cluster sampling method, 30 participants were selected and randomly assigned to the experimental and control groups. The tools discussed here included Child Behavior Checklist (CBCL, Raven's Progressive Matrixes, Teacher Report Form (TRF as well as a clinical interview with parents. Play therapy was provided weekly by group for the participants, in sixty-minute eight sessions. Participants were assessed in three stages of pre- interference post- interference and after two month intervals from completing sessions. SPSS18 and multi-variables covariance analysis method were used for analyzing data. Results: The results obtained by Mancova analysis showed that there was a significant decrease in oppositional defiant-disorder symptoms in comparison with control group reporting by parents and teacher (P < 0.001. In addition, the results indicated the same effect after two months. Conclusions: The results indicated the efficiency of group play therapy on decrease of oppositional defiant disorder symptoms among children. Accordingly using this treatment method on children was recommended to the therapists.

Quantum reflection of fast atoms from insulator surfaces: Eikonal description

Energy Technology Data Exchange (ETDEWEB)

Gravielle, M S; Miraglia, J E, E-mail: msilvia@iafe.uba.a, E-mail: miraglia@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, CONICET, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina) and Dpto. de Fisica, FCEN, Universidad de Buenos Aires (Argentina)

2009-11-01

Interference effects recently observed in grazing scattering of swift atoms from insulator surfaces are studied within a distorted-wave method - the surface eikonal approximation. This approach makes use of the eikonal wave function, involving axial channeled trajectories. The theory is applied to helium atoms colliding with a LiF(001) surface along low-index crystallographic directions. The roles played by the projectile polarization and the surface rumpling are investigated, finding that both effects are important for the description of the experimental projectile distributions.

Consequences of Play: A Systematic Review of the Effects of Online Gaming

Science.gov (United States)

Sublette, Victoria Anne; Mullan, Barbara

2012-01-01

Massively Multiplayer Online Games (MMOGs) have received considerable attention in news headlines describing gamers who have died while engaging in excessive play. However, more common physical and psychosocial effects attributed to online video gaming are social isolation, increased aggression, and negative academic and occupational consequences.…

Effect of computer game playing on baseline laparoscopic simulator skills.

Science.gov (United States)

Halvorsen, Fredrik H; Cvancarova, Milada; Fosse, Erik; Mjåland, Odd

2013-08-01

Studies examining the possible association between computer game playing and laparoscopic performance in general have yielded conflicting results and neither has a relationship between computer game playing and baseline performance on laparoscopic simulators been established. The aim of this study was to examine the possible association between previous and present computer game playing and baseline performance on a virtual reality laparoscopic performance in a sample of potential future medical students. The participating students completed a questionnaire covering the weekly amount and type of computer game playing activity during the previous year and 3 years ago. They then performed 2 repetitions of 2 tasks ("gallbladder dissection" and "traverse tube") on a virtual reality laparoscopic simulator. Performance on the simulator were then analyzed for association to their computer game experience. Local high school, Norway. Forty-eight students from 2 high school classes volunteered to participate in the study. No association between prior and present computer game playing and baseline performance was found. The results were similar both for prior and present action game playing and prior and present computer game playing in general. Our results indicate that prior and present computer game playing may not affect baseline performance in a virtual reality simulator.

Femtosecond laser-induced surface wettability modification of polystyrene surface

Science.gov (United States)

Wang, Bing; Wang, XinCai; Zheng, HongYu; Lam, YeeCheong

2016-12-01

In this paper, we demonstrated a simple method to create either a hydrophilic or hydrophobic surface. With femtosecond laser irradiation at different laser parameters, the water contact angle (WCA) on polystyrene's surface can be modified to either 12.7° or 156.2° from its original WCA of 88.2°. With properly spaced micro-pits created, the surface became hydrophilic probably due to the spread of the water droplets into the micro-pits. While with properly spaced micro-grooves created, the surface became rough and more hydrophobic. We investigated the effect of laser parameters on WCAs and analyzed the laser-treated surface roughness, profiles and chemical bonds by surface profilometer, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). For the laser-treated surface with low roughness, the polar (such as C—O, C=O, and O—C=O bonds) and non-polar (such as C—C or C—H bonds) groups were found to be responsible for the wettability changes. While for a rough surface, the surface roughness or the surface topography structure played a more significant role in the changes of the surface WCA. The mechanisms involved in the laser surface wettability modification process were discussed.

Effects of playing violent videogames on Chinese adolescents' pro-violence attitudes, attitudes toward others, and aggressive behavior.

Science.gov (United States)

Wei, Ran

2007-06-01

This study examines the effects of exposure to online videogame violence on Chinese adolescents' attitudes toward violence, empathy, and aggressive behavior. Results of bivariate analyses show that playing violent videogames on the Internet was associated with greater tolerance of violence, a lower emphatic attitude, and more aggressive behavior. Results of hierarchical regression analyses showed sustained relationships between exposure and pro-violent attitudes and empathy when exposure was examined simultaneously with gender, computer use, and Internet use. However, the linkage between exposure and aggression became non-significant, suggesting that the effects of playing violent videogames were greater for attitudinal outcomes than on overt behavior. Gender differences in playing videogames and in effects were also found.

Play Matters

DEFF Research Database (Denmark)

Sicart (Vila), Miguel Angel

? In Play Matters, Miguel Sicart argues that to play is to be in the world; playing is a form of understanding what surrounds us and a way of engaging with others. Play goes beyond games; it is a mode of being human. We play games, but we also play with toys, on playgrounds, with technologies and design......, but not necessarily fun. Play can be dangerous, addictive, and destructive. Along the way, Sicart considers playfulness, the capacity to use play outside the context of play; toys, the materialization of play--instruments but also play pals; playgrounds, play spaces that enable all kinds of play; beauty...

Magical arts: the poetics of play.

Science.gov (United States)

Jacobus, Mary

2005-01-01

The paper argues that links between play and magic in British Object Relations point to the persistence of aesthetic concerns within psychoanalysis. Magical thinking is present in British Object Relations psychoanalysis from its beginnings in Klein's play technique and early aesthetic writings, surfacing elsewhere in Susan Isaac's educational experiments and her theories of metaphor. Marion Milner's clinical account of the overlapping areas of illusion and symbol-formation in a boy's war-games link the primitive rituals of Frazer's "The Golden Bough" with her patient's creativity. In Winnicott's concept of the transitional object, the theory of play achieves its apotheosis as a diffusive theory of culture or "private madness," and as a paradigm for psychoanalysis itself. Tracing the non-positivistic, mystical, and poetical elements in British Object Relations underlines the extent to which aesthetics is not just entangled with psychoanalysis, but constitutive of it in its mid-twentieth century manifestations.

Magnetism and rotation effect on surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order

Energy Technology Data Exchange (ETDEWEB)

Abo-Dahab, S. M. [Taif University, Taif (Saudi Arabia); Abd-Alla, A. M. [SVU, Qena (Egypt); Khan, Aftab [Sohag University, Sohag (Egypt)

2015-08-15

The aim of this paper is to study the propagation of surface waves in a rotating fibre-reinforced viscoelastic media of higher order under the influence of magnetic field. The general surface wave speeds derived to study the effects of rotation and magnetic field on surface waves. Particular cases for Stoneley, Love and Rayleigh waves are also discussed and dispersion relation for the waves has been deduced. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. For order zero our results are well agreement to fibre-reinforced materials. Also by neglecting the reinforced elastic parameters, the results reduce to well known isotropic medium. It is observed that in a rotating medium the surface waves are dispersive. Also magnetic effects play a significant roll. It is observed that Love wave remain unaffected in a rotating medium but remain under the influence of magnetic field. Rayleigh waves are affected by rotation and magnetic field whereas Stoneley waves are independent of Maxwell stresses. It is also observed that, surface waves cannot propagate in a fast rotating medium or in the presence of magnetic field of high intensity. Numerical results for particular materials are given and illustrated graphically. The results indicate that the effect of rotation and magnetic field are very pronounced.

Magnetism and rotation effect on surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order

International Nuclear Information System (INIS)

Abo-Dahab, S. M.; Abd-Alla, A. M.; Khan, Aftab

2015-01-01

The aim of this paper is to study the propagation of surface waves in a rotating fibre-reinforced viscoelastic media of higher order under the influence of magnetic field. The general surface wave speeds derived to study the effects of rotation and magnetic field on surface waves. Particular cases for Stoneley, Love and Rayleigh waves are also discussed and dispersion relation for the waves has been deduced. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. For order zero our results are well agreement to fibre-reinforced materials. Also by neglecting the reinforced elastic parameters, the results reduce to well known isotropic medium. It is observed that in a rotating medium the surface waves are dispersive. Also magnetic effects play a significant roll. It is observed that Love wave remain unaffected in a rotating medium but remain under the influence of magnetic field. Rayleigh waves are affected by rotation and magnetic field whereas Stoneley waves are independent of Maxwell stresses. It is also observed that, surface waves cannot propagate in a fast rotating medium or in the presence of magnetic field of high intensity. Numerical results for particular materials are given and illustrated graphically. The results indicate that the effect of rotation and magnetic field are very pronounced.

Self-enhanced plasma discharge effect in the deposition of diamond-like carbon films on the inner surface of slender tube

Energy Technology Data Exchange (ETDEWEB)

Xu, Yi [Department of 702, Beihang University, Beijing (China); Li, Liuhe, E-mail: liliuhe@buaa.edu.cn [Department of 702, Beihang University, Beijing (China); Luo, Sida [Department of 702, Beihang University, Beijing (China); International Research Institute for Multidisciplinary Science, Beihang University, Beijing (China); Lu, Qiuyuan [Dong Feng Commercial Vehicle Technical Center, Dong Feng Commercial Vehicle Co., LTD, Wuhan (China); Gu, Jiabin; Lei, Ning [Department of 702, Beihang University, Beijing (China); Huo, Chunqin [Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education, Shenzhen University, Guangdong (China)

2017-01-30

Highlights: • Effect of inner surface materials of tubes on plasma discharge is examined. • Electron mean free path is used to analyze the films deposition. • Secondary electrons emitted from inner surface of tube enhance plasma discharge. - Abstract: Enhanced glow discharge plasma immersion ion implantation and deposition (EGD-PIII&D) have been proved to be highly effective for depositing diamond-like carbon (DLC) films on the inner surface of the slender quartz tube with a deposition rate of 1.3 μm/min. Such a high-efficiency DLC films deposition was explained previously as the short electrons mean free path to cause large collision frequency between electrons and neutral particles. However, in this paper, we found that the inner surface material of the tube itself play a vital role on the films deposition. To disclose the mechanism of this phenomenon, the effect of different inner surface materials on plasma discharge was experimentally and theoretically investigated. Then a self-enhancing plasma discharge is discovered. It is found that secondary electrons emitted from the inner surface material, whatever it is the tube inner surface or deposited DLC films, can dramatically enhance the plasma discharge to improve the DLC films deposition rate.

Effect of Sex and Body Mass Index on Children’s Physical Activity Intensity during Free Play at an Indoor Soft Play Center: An Exploratory Study

Science.gov (United States)

2017-01-01

Background: Indoor soft play can provide a safe but exciting physical activity opportunity regardless of environmental conditions. Relatively little is known about the quality or quantity of physical activity engaged in by children during indoor free soft play. The aim of this study was to evaluate the contribution indoor free soft play can make in enabling children to meet physical activity guidelines and to evaluate the effects of sex and body mass index category. Methods: Seventy-two boys and girls aged five to 10 years engaged in un-controlled indoor free soft play with a mean duration of 120.7 (27.1) min, during which physical activity was monitored using Actigraph accelerometers. Results: Children spent an average of 61.7 (24.2) min engaging in moderate to vigorous physical activity (MVPA) and 51.4% (n = 37) achieved the recommended 60 min of MVPA through the single visit to the indoor soft play center. Boys (68.3 (25.7) min) engaged in significantly (p < 0.05) more MVPA than girls (55.8 (21.4) min). Normal weight (65.7 (23.3) min) children engaged in significantly more MVPA than overweight children (48.0 (18.9) min). Conclusions: Attendance at a soft play indoor center has the potential to support children to engage in sufficient MVPA and overcome environmental factors that can restrict physical activity opportunities. PMID:28895904

The effects of size and surface modification of amorphous silica particles on biodistribution and liver metabolism in mice

Science.gov (United States)

Lu, Xiaoyan; Ji, Cai; Jin, Tingting; Fan, Xiaohui

2015-05-01

Engineered nanoparticles, with unconventional properties, are promising platforms for biomedical applications. Since they may interact with a wide variety of biomolecules, it is critical to understand the impact of the physicochemical properties of engineered nanoparticles on biological systems. In this study, the effects of particle size and surface modification alone or in combination of amorphous silica particles (SPs) on biological responses were determined using a suite of general toxicological assessments and metabonomics analysis in mice model. Our results suggested that amino or carboxyl surface modification mitigated the liver toxicity of plain-surface SPs. 30 nm SPs with amino surface modification were found to be the most toxic SPs among all the surface-modified SP treatments at the same dosage. When treatment dose was increased, submicro-sized SPs with amino or carboxyl surface modification also induced liver toxicity. Biodistribution studies suggested that 70 nm SPs were mainly accumulated in liver and spleen regardless of surface modifications. Interestingly, these two organs exhibited different uptake trends. Furthermore, metabonomics studies indicated that surface modification plays a more dominant role to affect the liver metabolism than particle size.

Surface elastic properties in silicon nanoparticles

Science.gov (United States)

Melis, Claudio; Giordano, Stefano; Colombo, Luciano

2017-09-01

The elastic behavior of the external surface of a solid body plays a key role in nanomechanical phenomena. While bulk elasticity enjoys the benefits of a robust theoretical understanding, many surface elasticity features remain unexplored: some of them are here addressed by blending together continuum elasticity and atomistic simulations. A suitable readdressing of the surface elasticity theory allows to write the balance equations in arbitrary curvilinear coordinates and to investigate the dependence of the surface elastic parameters on the mean and Gaussian curvatures of the surface. In particular, we predict the radial strain induced by surface effects in spherical and cylindrical silicon nanoparticles and provide evidence that the surface parameters are nearly independent of curvatures and, therefore, of the surface conformation.

Effects of video game playing on cerebral blood flow in young adults: a SPECT study.

Science.gov (United States)

Chou, Yuan-Hwa; Yang, Bang-Hung; Hsu, Ju-Wei; Wang, Shyh-Jen; Lin, Chun-Lung; Huang, Kai-Lin; Chien Chang, Alice; Lee, Shin-Min

2013-04-30

To study the impact of video game playing on the human brain, the effects of two video games playing on cerebral blood flow (CBF) in young adults were determined. Thirty healthy subjects comprising 18 males and 12 females who were familiar with video game playing were recruited. Each subject underwent three sessions of single photon emission computed tomography (SPECT) with a bolus injection of 20 mCi (99m)Tc ECD IV to measure their CBF. The first measurement was performed as baseline, the second and third measurements were performed after playing two different video games for 30 min, respectively. Statistic parametric mapping (SPM2) with Matlab 6.5 implemented on a personal computer was used for image analysis. CBF was significantly decreased in the prefrontal cortex and significantly increased in the temporal and occipital cortices after both video games playing. Furthermore, decreased CBF in the anterior cingulate cortex (ACC) which was significantly correlated with the number of killed characters was found after the violent game playing. The major finding of hypo-perfusion in prefrontal regions after video game playing is consistent with a previous study showing reduced or abnormal prefrontal cortex functions after video game playing. The second finding of decreased CBF in the ACC after playing the violent video game provides support for a previous hypothesis that the ACC might play a role in regulating violent behavior. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Cost-effectiveness of peer role play and standardized patients in undergraduate communication training.

Science.gov (United States)

Bosse, Hans Martin; Nickel, Martin; Huwendiek, Sören; Schultz, Jobst Hendrik; Nikendei, Christoph

2015-10-24

The few studies directly comparing the methodological approach of peer role play (RP) and standardized patients (SP) for the delivery of communication skills all suggest that both methods are effective. In this study we calculated the costs of both methods (given comparable outcomes) and are the first to generate a differential cost-effectiveness analysis of both methods. Medical students in their prefinal year were randomly assigned to one of two groups receiving communication training in Pediatrics either with RP (N = 34) or 19 individually trained SP (N = 35). In an OSCE with standardized patients using the Calgary-Cambridge Referenced Observation Guide both groups achieved comparable high scores (results published). In this study, corresponding costs were assessed as man-hours resulting from hours of work of SP and tutors. A cost-effectiveness analysis was performed. Cost-effectiveness analysis revealed a major advantage for RP as compared to SP (112 vs. 172 man hours; cost effectiveness ratio .74 vs. .45) at comparable performance levels after training with both methods. While both peer role play and training with standardized patients have their value in medical curricula, RP has a major advantage in terms of cost-effectiveness. This could be taken into account in future decisions.

Surface effects in controlled thermonuclear fusion

International Nuclear Information System (INIS)

Kaminsky, M.

1975-08-01

During the operation of large size plasma facilities and future controlled thermonuclear fusion reactors the surfaces of such major components as container walls, beam limiters, diverter walls and beam-dump walls of the injector region will be exposed to particle and photon bombardment from primary plasma radiations and from secondary radiations. Such radiations can cause, for example, physical and chemical sputtering, blistering, particle- and photon-impact induced desorption, secondary electron and x-ray emission, backscattering, nuclear reactions, photo-decomposition of surface compounds, photocatalysis, and vaporization. Such effects in turn can (a) seriously damage and erode the bombarded surface and (b) release major quantities of impurities which will contaminate the plasma. The effects of some of the major surface phenomena on the operation of plasma facilities and future fusion reactors are discussed

Guiding Future Early Childhood Educators to Reclaim Their Own Play as a Foundation for Becoming Effective Advocates for Children's Play

Science.gov (United States)

Nicholson, Julie; Shimpi, Priya Mariana

2015-01-01

Two case studies describe how two women, enrolled in an undergraduate course on play, were guided to examine play across their lifespan, critique the barriers that led to a decline in their play from childhood to young adulthood, and engage in cycles of documentation, dialogue, and analysis of their adult play experiences in order to discover…

Effect of Surface Treatment on the Surface Characteristics of AISI 316L Stainless Steel

Science.gov (United States)

Trigwell, Steve; Selvaduray, Guna

2005-01-01

The ability of 316L stainless steel to maintain biocompatibility, which is dependent upon the surface characteristics, is critical to its effectiveness as an implant material. The surfaces of mechanically polished (MP), electropolished (EP) and plasma treated 316L stainless steel coupons were characterized by X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) for chemical composition, Atomic Force Microscopy for surface roughness, and contact angle measurements for critical surface tension. All surfaces had a Ni concentration that was significantly lower than the bulk concentration of -43%. The Cr content of the surface was increased significantly by electropolishing. The surface roughness was also improved significantly by electropolishing. Plasma treatment had the reverse effect - the surface Cr content was decreased. It was also found that the Cr and Fe in the surface exist in both the oxide and hydroxide states, with the ratios varying according to surface treatment.

Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

Science.gov (United States)

Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad; Rafii-Tabar, Hashem

2014-05-01

Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin-Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

International Nuclear Information System (INIS)

Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad; Rafii-Tabar, Hashem

2014-01-01

Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin–Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

Energy Technology Data Exchange (ETDEWEB)

Ghavanloo, Esmaeal, E-mail: ghavanloo@shirazu.ac.ir [School of Mechanical Engineering, Shiraz University, Shiraz 71963-16548 (Iran, Islamic Republic of); Fazelzadeh, S. Ahmad [School of Mechanical Engineering, Shiraz University, Shiraz 71963-16548 (Iran, Islamic Republic of); Rafii-Tabar, Hashem [Department of Medical Physics and Biomedical Engineering, Research Center for Medical Nanotechnology and Tissue Engineering, Shahid Beheshti University of Medical Sciences, Evin, Tehran (Iran, Islamic Republic of); Computational Physical Sciences Research Laboratory, School of Nano-Science, Institute for Research in Fundamental Sciences (IPM), Tehran (Iran, Islamic Republic of)

2014-05-01

Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin–Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

Modeling of liquid–gas meniscus for textured surfaces: effects of curvature and local slip length

International Nuclear Information System (INIS)

Gaddam, Anvesh; Garg, Mayank; Agrawal, Amit; Joshi, Suhas S

2015-01-01

Surface texturing at the micro/nanolevel allows air to be trapped in sufficiently small cavities, thereby reducing the flow resistance over the surface in the laminar regime. The nature of the liquid–gas meniscus plays an important role in defining the boundary condition and it depends on the flow conditions and geometrical properties of textures. In the present work, we employ the unsteady volume of fluid model to investigate the behavior of the liquid–gas meniscus for ridges arranged normal to the flow direction to substantiate the frictional resistance of flow in a microchannel. It is found that the assumption of ‘zero shear stress’ at the liquid–gas interface grossly overpredicts the effective slip length with meniscus curvature and local partial slip length playing the dominant role. Numerical simulations performed in the laminar regime (20  <  Re  <  120) over single layered ridges normal to the flow direction revealed the effect of texture geometry on the reduction in pressure drop. In single layered structures, lotus-like geometries exhibited a greater reduction in drag (more than 30%) when compared to all other texture geometries. It is recognized that the flow experiences expansion and contraction cycles as it flows over the transverse ridges increasing the frictional resistance. Our findings will help to modify the boundary condition at the liquid–gas meniscus for accurate modeling in the laminar regime and to optimize the texture geometry to improve drag reduction. (paper)

Surface phonons

CERN Document Server

Wette, Frederik

1991-01-01

In recent years substantial progress has been made in the detection of surface phonons owing to considerable improvements in inelastic rare gas scattering tech­ niques and electron energy loss spectroscopy. With these methods it has become possible to measure surface vibrations in a wide energy range for all wave vectors in the two-dimensional Brillouin zone and thus to deduce the complete surface phonon dispersion curves. Inelastic atomic beam scattering and electron energy loss spectroscopy have started to play a role in the study of surface phonons similar to the one played by inelastic neutron scattering in the investigation of bulk phonons in the last thirty years. Detailed comparison between experimen­ tal results and theoretical studies of inelastic surface scattering and of surface phonons has now become feasible. It is therefore possible to test and to improve the details of interaction models which have been worked out theoretically in the last few decades. At this point we felt that a concise, co...

The Effects of Playing Educational Video Games on Kindergarten Achievement.

Science.gov (United States)

Din, Feng S.; Calao, Josephine

2001-01-01

Investigated whether kindergarten students who played Sony PlayStation educational video games for 40 minutes daily for 11 weeks learned better than peers who did not play such games. Found that the experimental group gained significantly more than the control group in spelling and decoding on the Wide Range Achievement Test-R3. Found no…

On the Stress Transfer of Nanoscale Interlayer with Surface Effects

Directory of Open Access Journals (Sweden)

Quan Yuan

2018-01-01

Full Text Available An improved shear-lag model is proposed to investigate the mechanism through which the surface effect influences the stress transfer of multilayered structures. The surface effect of the interlayer is characterized in terms of interfacial stress and surface elasticity by using Gurtin–Murdoch elasticity theory. Our calculation result shows that the surface effect influences the efficiency of stress transfer. The surface effect is enhanced with decreasing interlayer thickness and elastic modulus. Nonuniform and large residual surface stress distribution amplifies the influence of the surface effect on stress concentration.

Beyond self-selection in video game play: an experimental examination of the consequences of massively multiplayer online role-playing game play.

Science.gov (United States)

Smyth, Joshua M

2007-10-01

There is burgeoning interest in the study of video games. Existing work is limited by the use of correlational designs and is thus unable to make causal inferences or remove self-selection biases from observed results. The recent development of online, socially integrated video games (massively multiplayer online role-playing games [MMORPGs]) has created a new experience for gamers. This randomized, longitudinal study examined the effects of being assigned to play different video game types on game usage, health, well-being, sleep, socializing, and academics. One hundred 18- to 20-year-old participants (73% male; 68% Caucasian) were randomly assigned to play arcade, console, solo computer, or MMORPG games for 1 month. The MMORPG group differed significantly from other groups after 1 month, reporting more hours spent playing, worse health, worse sleep quality, and greater interference in "real-life" socializing and academic work. In contrast, this group also reported greater enjoyment in playing, greater interest in continuing to play, and greater acquisition of new friendships. MMORPGs represent a different gaming experience with different consequences than other types of video games and appear to pose both unique risks and benefits from their use.

Why do Dolphins Play?

Directory of Open Access Journals (Sweden)

Stan A. Kuczaj

2014-05-01

Full Text Available Play is an important aspect of dolphin life, perhaps even an essential one. Play provides opportunities for dolphin calves to practice and perfect locomotor skills, including those involved in foraging and mating strategies and behaviors. Play also allows dolphin calves to learn important social skills and acquire information about the characteristics and predispositions of members of their social group, particularly their peers. In addition to helping dolphin calves learn how to behave, play also provides valuable opportunities for them to learn how to think. The ability to create and control play contexts enables dolphins to create novel experiences for themselves and their playmates under relatively safe conditions. The behavioral variability and individual creativity that characterize dolphin play yield ample opportunities for individual cognitive development as well as social learning, and sometimes result in innovations that are reproduced by other members of the group. Although adults sometimes produce innovative play, calves are the primary source of such innovations. Calves are also more likely to imitate novel play behaviors than are adults, and so calves contribute significantly to both the creation and transmission of novel play behaviors within a group. Not unexpectedly, then, the complexity of dolphin play increases with the involvement of peers. As a result, the opportunity to observe and/or interact with other dolphin calves enhances the effects of play on the acquisition and maintenance of flexible problem solving skills, the emergence and strengthening of social and communicative competencies, and the establishment of social relationships. It seems that play may have evolved to help young dolphins learn to adapt to novel situations in both their physical and social worlds, the beneficial result being a set of abilities that increases the likelihood that an individual survives and reproduces.

Surface States and Effective Surface Area on Photoluminescent P-Type Porous Silicon

Science.gov (United States)

Weisz, S. Z.; Porras, A. Ramirez; Resto, O.; Goldstein, Y.; Many, A.; Savir, E.

1997-01-01

The present study is motivated by the possibility of utilizing porous silicon for spectral sensors. Pulse measurements on the porous-Si/electrolyte system are employed to determine the surface effective area and the surface-state density at various stages of the anodization process used to produce the porous material. Such measurements were combined with studies of the photoluminescence spectra. These spectra were found to shift progressively to the blue as a function of anodization time. The luminescence intensity increases initially with anodization time, reaches a maximum and then decreases with further anodization. The surface state density, on the other hand, increases with anodization time from an initial value of about 2 x 10(exp 12)/sq cm surface to about 1013 sq cm for the anodized surface. This value is attained already after -2 min anodization and upon further anodization remains fairly constant. In parallel, the effective surface area increases by a factor of 10-30. This behavior is markedly different from the one observed previously for n-type porous Si.

Acute toxicity of quantum dots on late pregnancy mice: Effects of nanoscale size and surface coating

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wanyi [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); The Second Affiliated Hospital of Nanchang University, Nanchang 330000 (China); Yang, Lin; Kuang, Huijuan; Yang, Pengfei [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Aguilar, Zoraida P.; Wang, Andrew [Ocean NanoTech, LLC, Springdale, AR72764 (United States); Fu, Fen, E-mail: fu_fen@163.com [The Second Affiliated Hospital of Nanchang University, Nanchang 330000 (China); Xu, Hengyi, E-mail: kidyxu@163.com [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China)

2016-11-15

Graphical abstract: In spite of the immense benefits from quantum dots (QDs), there is scanty information regarding their toxicity mechanisms against late pregnancy. - Highlights: • QDs and CdCl{sub 2} were effectively blocked by the placental barrier. • CdSe QDs more effectively altered the expression levels of susceptive genes. • Nanoscale size of QDs is more important than free Cd in inducing toxicity. • Outer surface shell coating of QDs played a protective role. - Abstract: In this study, the effects of cadmium containing QDs (such as CdSe/ZnS and CdSe QDs) and bulk CdCl{sub 2} in pregnant mice, their fetuses, and the pregnancy outcomes were investigated. It was shown that although the QDs and bulk CdCl{sub 2} were effectively blocked by the placental barrier, the damage on the placenta caused by CdSe QDs still led to fetus malformation, while the mice in CdSe/ZnS QDs treatment group exhibited slightly hampered growth but showed no significant abnormalities. Moreover, the Cd contents in the placenta and the uterus of CdSe QDs and CdSe/ZnS QDs treatment groups showed significantly higher than the CdCl{sub 2} treated group which indicated that the nanoscale size of the QDs allowed relative ease of entry into the gestation tissues. In addition, the CdSe QDs more effectively altered the expression levels of susceptive genes related to cell apoptosis, dysplasia, metal transport, cryptorrhea, and oxidative stress, etc. These findings suggested that the nanoscale size of the QDs were probably more important than the free Cd in inducing toxicity. Furthermore, the results indicated that the outer surface shell coating played a protective role in the adverse effects of QDs on late pregnancy mice.

Effect of play therapy on behavioral problems of maladjusted preschool children.

Science.gov (United States)

Jafari, Niloufar; Mohammadi, Mohammad Reza; Khanbani, Mehdi; Farid, Saeedeh; Chiti, Parisa

2011-01-01

The present research was conducted to study the effect of play therapy on reducing behavioral problems of children with oppositional defiant disorder. Using multistage cluster sampling, regions 6, 7, and 8 in Tehran were selected. Among kindergartens of these areas, 3 kindergartens which were supported by the welfare organization were randomly selected. Of all the pre-school children of these 3 kindergartens, 40 children who could have behavioral disorder, according to their teachers and parents, were carefully tested. Of them, 16 children who showed severe symptoms of oppositional defiant disorder, were selected via the results obtained from the child symptom inventory questionnaire (CSI-4), teacher's form, and a researcher-made self-control checklist, Then, the subjects were randomly divided into one control and one experimental group. This research is quasi-experimental, and is conducted using pre-test, post-test, and control group. Values of the calculated F for oppositional defiant disorder in control group and experimental group was meaningful after fixing the effect of pre-test (Pplay therapy reduced severity of ADHD in those children in experimental group compared to those in control group who did not receive such instructions. Results of this research demonstrates that children's disobedience can be reduced by play therapy.

Effect of laser cutting parameters on surface roughness of stainless steel 307

Directory of Open Access Journals (Sweden)

Amal NASSAR

2016-12-01

Full Text Available Optimal parameters of laser cutting are an important step to improve surface quality of cutting edge in the laser cutting of stainless steel 307. This paper presents a new approach for optimizing the cutting parameters on stainless steel. Based on 33 full factorial experimental design, cutting experiments were conducted for stainless steel 307 plates using a laser machine (AMADA FONT 3015. The cutting parameters such as, cutting speed, cutting power and gas pressure are optimized for maximizing surface quality. The results indicated that cutting power and cutting speed play an important role in surface quality.

Effects of playing mathematics computer games on primary school students' multiplicative reasoning ability

NARCIS (Netherlands)

Bakker, Marjoke; Van den Heuvel-Panhuizen, M.; Robitzsch, Alexander

2015-01-01

This study used a large-scale cluster randomized longitudinal experiment (N=719; 35schools) to investigate the effects of online mathematics mini-games on primary school students' multiplicative reasoning ability. The experiment included four conditions: playing at school, integrated in a lesson

Problematic Game Play: The Diagnostic Value of Playing Motives, Passion, and Playing Time in Men

Directory of Open Access Journals (Sweden)

Julia Kneer

2015-04-01

Full Text Available Internet gaming disorder is currently listed in the DSM—not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1 analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2 testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81 that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing.

Problematic game play: the diagnostic value of playing motives, passion, and playing time in men.

Science.gov (United States)

Kneer, Julia; Rieger, Diana

2015-04-30

Internet gaming disorder is currently listed in the DSM-not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1) analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2) testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81) that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing.

Effect of Preoperative Play Interventions on Post Surgery Anxiety

Directory of Open Access Journals (Sweden)

Narges Alirezaei

2008-12-01

Full Text Available "n "nObjective: Many studies have shown that the level of postoperative distress and anxiety in children is associated with the amount of anxiety during the pre operative period. In this study, we compared the effect of pre-operational attending in a playroom and using play activities on the level of anxiety increment after surgery in an intervention and a control group of Iranian children. "n "nMethod: In a clinical trial, 75 children aged 5 to 12 enrolled in the intervention and the control group. The anxiety symptoms were assessed using State-Trait Anxiety Inventory for Children, Revised Children's Manifest Anxiety Scale, and Yale modified Pre operative Anxiety Scale. The mean differences of pre and post operative anxiety scores were calculated and compared using the ANCOVA statistical method. "n "nResults: The two groups had similar demographic characteristics except for age which was higher in the control group. The baseline anxiety score was lower in the intervention compare to the control group and was statistically significant. There was a significant reduction in the trend of anxiety increment after surgery in the intervention group in comparison to the control group. "n "nConclusion: Attending in playrooms and using play activities may reduce the trend of increment in the anxiety level induced by surgical procedures.

The effects of gender, motor skills and play area on the free play activities of 8-11 year old school children.

Science.gov (United States)

Harten, Nathan; Olds, Tim; Dollman, Jim

2008-09-01

Two studies were conducted to examine the interactions between gender, play area, motor skills and free play activity in 8-11 year old school children. In both studies, boys were more active than girls. In boys, but not in girls, energy expenditure was greater for high-skill than for low-skill children (p = 0.0002), and increased as play area increased (p = 0.01). These results suggest that motor skills and play space are important variables in determining the free play activity of boys, but not of girls. This may be related to widely different play styles among boys and girls.

Effects of shrub and tree cover increase on the near-surface atmosphere in northern Fennoscandia

Directory of Open Access Journals (Sweden)

J. H. Rydsaa

2017-09-01

Full Text Available Increased shrub and tree cover in high latitudes is a widely observed response to climate change that can lead to positive feedbacks to the regional climate. In this study we evaluate the sensitivity of the near-surface atmosphere to a potential increase in shrub and tree cover in the northern Fennoscandia region. We have applied the Weather Research and Forecasting (WRF model with the Noah-UA land surface module in evaluating biophysical effects of increased shrub cover on the near-surface atmosphere at a fine resolution (5.4 km  ×  5.4 km. Perturbation experiments are performed in which we prescribe a gradual increase in taller vegetation in the alpine shrub and tree cover according to empirically established bioclimatic zones within the study region. We focus on the spring and summer atmospheric response. To evaluate the sensitivity of the atmospheric response to inter-annual variability in climate, simulations were conducted for two contrasting years, one warm and one cold. We find that shrub and tree cover increase leads to a general increase in near-surface temperatures, with the highest influence seen during the snowmelt season and a more moderate effect during summer. We find that the warming effect is stronger in taller vegetation types, with more complex canopies leading to decreases in the surface albedo. Counteracting effects include increased evapotranspiration, which can lead to increased cloud cover, precipitation, and snow cover. We find that the strength of the atmospheric feedback is sensitive to snow cover variations and to a lesser extent to summer temperatures. Our results show that the positive feedback to high-latitude warming induced by increased shrub and tree cover is a robust feature across inter-annual differences in meteorological conditions and will likely play an important role in land–atmosphere feedback processes in the future.

Laser surface treatment of polyamide and NiTi alloy and the effects on mesenchymal stem cell response

Science.gov (United States)

Waugh, D. G.; Lawrence, J.; Shukla, P.; Chan, C.; Hussain, I.; Man, H. C.; Smith, G. C.

2015-07-01

Mesenchymal stem cells (MSCs) are known to play important roles in development, post-natal growth, repair, and regeneration of mesenchymal tissues. What is more, surface treatments are widely reported to affect the biomimetic nature of materials. This paper will detail, discuss and compare laser surface treatment of polyamide (Polyamide 6,6), using a 60 W CO2 laser, and NiTi alloy, using a 100 W fiber laser, and the effects of these treatments on mesenchymal stem cell response. The surface morphology and composition of the polyamide and NiTi alloy were studied by scanning electron microscopy (SEM) and X-ray photoemission spectroscopy (XPS), respectively. MSC cell morphology cell counting and viability measurements were done by employing a haemocytometer and MTT colorimetric assay. The success of enhanced adhesion and spreading of the MSCs on each of the laser surface treated samples, when compared to as-received samples, is evidenced in this work.

Effects of communication training on real practice performance: a role-play module versus a standardized patient module.

NARCIS (Netherlands)

Schlegel, C.; Woermann, U.; Shaha, M.; Rethans, J.J.; Vleuten, C.P.M. van der

2012-01-01

This study investigated the effectiveness of modules involving standardized patients and role-plays on training communication skills. The first module involved standardized patients and an Objective Structured Clinical Examination (OSCE); the second module consisted of peer role-plays and a written

Surface Effect on Oil Transportation in Nanochannel: a Molecular Dynamics Study.

Science.gov (United States)

Zheng, Haixia; Du, Yonggang; Xue, Qingzhong; Zhu, Lei; Li, Xiaofang; Lu, Shuangfang; Jin, Yakang

2017-12-01

In this work, we investigate the dynamics mechanism of oil transportation in nanochannel using molecular dynamics simulations. It is demonstrated that the interaction between oil molecules and nanochannel has a great effect on the transportation properties of oil in nanochannel. Because of different interactions between oil molecules and channel, the center of mass (COM) displacement of oil in a 6-nm channel is over 30 times larger than that in a 2-nm channel, and the diffusion coefficient of oil molecules at the center of a 6-nm channel is almost two times more than that near the channel surface. Besides, it is found that polarity of oil molecules has the effect on impeding oil transportation, because the electrostatic interaction between polar oil molecules and channel is far larger than that between nonpolar oil molecules and channel. In addition, channel component is found to play an important role in oil transportation in nanochannel, for example, the COM displacement of oil in gold channel is very few due to great interaction between oil and gold substrate. It is also found that nano-sized roughness of channel surface greatly influences the speed and flow pattern of oil. Our findings would contribute to revealing the mechanism of oil transportation in nanochannels and therefore are very important for design of oil extraction in nanochannels.

The therapeutic power of play: examining the play of young children with leukaemia.

Science.gov (United States)

Gariépy, N; Howe, N

2003-11-01

The therapeutic function of play has been investigated in relation to recognized stressors such as hospitalization, illness and medical treatments for ill children. While medical treatments in the past 30 years have improved survival rates, children's psychological experiences and quality of life during and after their illness have received limited attention. The present study investigated the therapeutic effects of play on 3- to 5-year-old children with leukaemia compared with a control group of healthy children. The participants with leukaemia (n = 11) were from the external oncology clinic of an urban children's hospital; control children (n = 11) attended a day care centre. Measures included children's experience of stress, social and cognitive play behaviours, and daily mood. A series of manova revealed that the children with leukaemia, compared with the control children, engaged in (a) significantly fewer total play behaviours, and in particular less (b) parallel, (c) group and (d) dramatic play. Pearson correlations revealed significant relationships between reports of 'being happy' and play only for children with leukaemia. Quantitative and qualitative analyses revealed a pattern of repetitive play activities week after week for children with leukaemia, but not controls. Findings are discussed in light of the theoretical and practical implications for children undergoing treatment for leukaemia.

Vibration of Piezoelectric Nanowires Including Surface Effects

Directory of Open Access Journals (Sweden)

R. Ansari

2014-04-01

Full Text Available In this paper, surface and piezoelectric effects on the vibration behavior of nanowires (NWs are investigated by using a Timoshenko beam model. The electric field equations and the governing equations of motion for the piezoelectric NWs are derived with the consideration of surface effects. By the exact solution of the governing equations, an expression for the natural frequencies of NWs with simply-supported boundary conditions is obtained. The effects of piezoelectricity and surface effects on the vibrational behavior of Timoshenko NWs are graphically illustrated. A comparison is also made between the predictions of Timoshenko beam model and those of its Euler-Bernoulli counterpart. Additionally, the present results are validated through comparison with the available data in the literature.

Fabrication of zero contact angle ultra-super hydrophilic surfaces.

Science.gov (United States)

Jothi Prakash, C G; Clement Raj, C; Prasanth, R

2017-06-15

Zero contact angle surfaces have been created with the combined effect of nanostructure and UV illumination. The contact angle of titanium surface has been optimized to 3.25°±1°. with nanotubular structures through electrochemical surface modification. The porosity and surface energy of tubular TiO 2 layer play critical role over the surface wettability and the hydrophilicity of the surface. The surface free energy has been enhanced from 23.72mJ/m 2 (bare titanium surface) to 87.11mJ/m 2 (nanotubular surface). Similar surface with TiO 2 nanoparticles coating shows superhydrophilicity with contact angle up to 5.63°±0.95°. This implies liquid imbibition and surface curvature play a crucial role in surface hydrophilicity. The contact angle has been further reduced to 0°±0.86° by illuminating the surface with UV radiation. Results shows that by tuning the nanotube morphology, highly porous surfaces can be fabricated to reduce contact angle and enhance wettability. This study provides an insight into the inter-relationship between surface structural factors and ultra-superhydrophilic surfaces which can help to optimize thermal hydraulic and self cleaning surfaces. Copyright © 2017. Published by Elsevier Inc.

Surface roughness effects on heat transfer in Couette flow

International Nuclear Information System (INIS)

Elia, G.G.

1981-01-01

A cell theory for viscous flow with rough surfaces is applied to two basic illustrative heat transfer problems which occur in Couette flow. Couette flow between one adiabatic surface and one isothermal surface exhibits roughness effects on the adiabatic wall temperature. Two types of rough cell adiabatic surfaces are studied: (1) perfectly insulating (the temperature gradient vanishes at the boundary of each cell); (2) average insulating (each cell may gain or lose heat but the total heat flow at the wall is zero). The results for the roughness on a surface in motion are postulated to occur because of fluid entrainment in the asperities on the moving surface. The symmetry of the roughness effects on thermal-viscous dissipation is discussed in detail. Explicit effects of the roughness on each surface, including combinations of roughness values, are presented to enable the case where the two surfaces may be from different materials to be studied. The fluid bulk temperature rise is also calculated for Couette flow with two ideal adiabatic surfaces. The effect of roughness on thermal-viscous dissipation concurs with the viscous hydrodynamic effect. The results are illustrated by an application to lubrication. (Auth.)

Multiresolution molecular mechanics: Surface effects in nanoscale materials

Energy Technology Data Exchange (ETDEWEB)

Yang, Qingcheng, E-mail: qiy9@pitt.edu; To, Albert C., E-mail: albertto@pitt.edu

2017-05-01

Surface effects have been observed to contribute significantly to the mechanical response of nanoscale structures. The newly proposed energy-based coarse-grained atomistic method Multiresolution Molecular Mechanics (MMM) (Yang, To (2015), ) is applied to capture surface effect for nanosized structures by designing a surface summation rule SR{sup S} within the framework of MMM. Combined with previously proposed bulk summation rule SR{sup B}, the MMM summation rule SR{sup MMM} is completed. SR{sup S} and SR{sup B} are consistently formed within SR{sup MMM} for general finite element shape functions. Analogous to quadrature rules in finite element method (FEM), the key idea to the good performance of SR{sup MMM} lies in that the order or distribution of energy for coarse-grained atomistic model is mathematically derived such that the number, position and weight of quadrature-type (sampling) atoms can be determined. Mathematically, the derived energy distribution of surface area is different from that of bulk region. Physically, the difference is due to the fact that surface atoms lack neighboring bonding. As such, SR{sup S} and SR{sup B} are employed for surface and bulk domains, respectively. Two- and three-dimensional numerical examples using the respective 4-node bilinear quadrilateral, 8-node quadratic quadrilateral and 8-node hexahedral meshes are employed to verify and validate the proposed approach. It is shown that MMM with SR{sup MMM} accurately captures corner, edge and surface effects with less 0.3% degrees of freedom of the original atomistic system, compared against full atomistic simulation. The effectiveness of SR{sup MMM} with respect to high order element is also demonstrated by employing the 8-node quadratic quadrilateral to solve a beam bending problem considering surface effect. In addition, the introduced sampling error with SR{sup MMM} that is analogous to numerical integration error with quadrature rule in FEM is very small. - Highlights: �

Comparison of Effects of Running and Playing Exercises on Differential Leucocyte Count in Young Elite Athletes

Science.gov (United States)

Cenikli, Abdullah

2016-01-01

The aims of the present research are to test the effects of running and playing exercises on leucocyte and differential leucocyte accounts, and to test the possible differences between running and playing exercises in terms of leucocyte accounts. They were thirty two male young soccer players. Participants arrived at the laboratory after a 12-hour…

All-(111) surface silicon nanowire field effect transistor devices: Effects of surface preparations

NARCIS (Netherlands)

Masood, M.N.; Carlen, Edwin; van den Berg, Albert

2014-01-01

Etching/hydrogen termination of All-(111) surface silicon nanowire field effect (SiNW-FET) devices developed by conventional photolithography and plane dependent wet etchings is studied with X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and

Surface effects on the red giant branch

Science.gov (United States)

Ball, W. H.; Themeßl, N.; Hekker, S.

2018-05-01

Individual mode frequencies have been detected in thousands of individual solar-like oscillators on the red giant branch (RGB). Fitting stellar models to these mode frequencies, however, is more difficult than in main-sequence stars. This is partly because of the uncertain magnitude of the surface effect: the systematic difference between observed and modelled frequencies caused by poor modelling of the near-surface layers. We aim to study the magnitude of the surface effect in RGB stars. Surface effect corrections used for main-sequence targets are potentially large enough to put the non-radial mixed modes in RGB stars out of order, which is unphysical. Unless this can be circumvented, model-fitting of evolved RGB stars is restricted to the radial modes, which reduces the number of available modes. Here, we present a method to suppress gravity modes (g-modes) in the cores of our stellar models, so that they have only pure pressure modes (p-modes). We show that the method gives unbiased results and apply it to three RGB solar-like oscillators in double-lined eclipsing binaries: KIC 8410637, KIC 9540226 and KIC 5640750. In all three stars, the surface effect decreases the model frequencies consistently by about 0.1-0.3 μHz at the frequency of maximum oscillation power νmax, which agrees with existing predictions from three-dimensional radiation hydrodynamics simulations. Though our method in essence discards information about the stellar cores, it provides a useful step forward in understanding the surface effect in RGB stars.

The Powerful Effect of Play in a Child's Education

Science.gov (United States)

Rivera, Miquela

2009-01-01

Play is a great equalizer. It is a universal, natural human pursuit. It need not--and should not--be based on or require expensive toys. Instead, children need an atmosphere in which exploration and play are valued and encouraged, a print-rich environment in which books--these can be borrowed from a library--encourage verbal skills; materials…

Effect of play therapy on behavioral problems of mal-adjusted pre-school children

Directory of Open Access Journals (Sweden)

Mehdi Khanbani

2011-01-01

Full Text Available Objective: The present research was conducted to study the effect of play therapy on reducing behavioral problems of mal-adjusted children (children with oppositional defiant disorder. Method: By using multistage cluster sampling, regions 6, 7, and 8 in Tehran were selected, and among kindergartens of these areas, 3 kindergartens under the support of welfare organization were randomly selected. From pre-school children of these 3 kindergartens, 40 children that could have behavioral disorder according to their teachers and parents complaints, were carefully tested, and among them, by the results obtained from child symptom inventory questionnaire (CSI-4, teacher's form, and a researcher-made self-control checklist, 16 children who showed severe symptoms of oppositional defiant disorder were selected, and they were randomly divided into control and experimental group. This research is quasi-experimental, and is done by the use of pre-test, post-test, and control group. Results: values of calculated F for oppositional defiant disorder in control and experimental group is meaningful after fixing the effect of pre-test (F(1,12=74/94, P<0/001 so there is a meaningful difference between means of disobedience disorder post-test scores in experimental and control group by having the fixed effect of pre-test effect. Comparison of adjusted means of 2 groups shows that the mean of attention-deficit hyperactivity disorder (ADHD in experimental group (M=14/09 is lower than control group (M=36/66. Therefore, applying play therapy in experimental group in comparison with control group, who did not receive these instructions, caused reduction in attention-deficit hyperactivity disorder (ADHD in pre-school children. Conclusion: Results of this research show that the children's disobedience is reduced by benefiting from play therapy.

Limitations of the efficacy of surface disinfection in the healthcare setting.

Science.gov (United States)

Williams, Gareth J; Denyer, Stephen P; Hosein, Ian K; Hill, Dylan W; Maillard, Jean-Yves

2009-06-01

We examined the efficacy of 2 commercially available wipes to effectively remove, kill, and prevent the transfer of both methicillin-resistant and methicillin-susceptible Staphylococcus aureus from contaminated surfaces. Although wipes play a role in decreasing the number of pathogenic bacteria from contaminated surfaces, they can potentially transfer bacteria to other surfaces if they are reused.

Effects of sub-minimum inhibitory concentrations of ciprofloxacin on enteroaggregative Escherichia coli and the role of the surface protein dispersin

Energy Technology Data Exchange (ETDEWEB)

Fowlkes, Jason Davidson [ORNL; Doktycz, Mitchel John [ORNL; Allison, David Post [ORNL

2011-01-01

Enteroaggregative Escherichia coli (EAEC) are bacterial pathogens that cause watery diarrhoea, which is often persistent and can be inflammatory. The antibiotic ciprofloxacin is used to treat EAEC infections, but a full understanding of the antimicrobial effects of ciprofloxacin is needed for more efficient treatment of bacterial infections. In this study, it was found that sub-minimum inhibitory concentrations (sub-MICs) of ciprofloxacin had an inhibitory effect on EAEC adhesion to glass and mammalian HEp-2 cells. It was also observed that bacterial surface properties play an important role in bacterial sensitivity to ciprofloxacin. In an EAEC mutant strain where the hydrophobic positively charged surface protein dispersin was absent, sensitivity to ciprofloxacin was reduced compared with the wild-type strain. Identified here are several antimicrobial effects of ciprofloxacin at sub-MIC concentrations indicating that bacterial surface hydrophobicity affects the response to ciprofloxacin. Investigating the effects of sub-MIC doses of antibiotics on targeted bacteria could help to further our understanding of bacterial pathogenicity and elucidate future antibiotic treatment modalities.

Effect of anodic surface treatment on PAN-based carbon fiber and its relationship to the fracture toughness of the carbon fiber-reinforced polymer composites

DEFF Research Database (Denmark)

Sarraf, Hamid; Skarpova, Ludmila

2008-01-01

The effect of anodic surface treatment on the polyacrylonitrile (PAN)-based carbon fibers surface properties and the mechanical behavior of the resulting carbon fiber-polymer composites has been studied in terms of the contact angle measurements of fibers and the fracture toughness of composites...... in the fiber surface nature and the mechanical interfacial properties between the carbon fiber and epoxy resin matrix of the resulting composites, i.e., the fracture toughness. We suggest that good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices...

Surface layer effects on waste glass corrosion

International Nuclear Information System (INIS)

Feng, X.

1993-01-01

Water contact subjects waste glass to chemical attack that results in the formation of surface alteration layers. Two principal hypotheses have been advanced concerning the effect of surface alteration layers on continued glass corrosion: (1) they act as a mass transport barrier and (2) they influence the chemical affinity of the glass reaction. In general, transport barrier effects have been found to be less important than affinity effects in the corrosion of most high-level nuclear waste glasses. However, they can be important under some circumstances, for example, in a very alkaline solution, in leachants containing Mg ions, or under conditions where the matrix dissolution rate is very low. The latter suggests that physical barrier effect may affect the long-term glass dissolution rate. Surface layers influence glass reaction affinity through the effects of the altered glass and secondary phases on the solution chemistry. The reaction affinity may be controlled by various precipitates and crystalline phases, amorphous silica phases, gel layer, or all the components of the glass. The surface alteration layers influence radionuclide release mainly through colloid formation, crystalline phase incorporation, and gel layer retention. This paper reviews current understanding and uncertainties

Effects of surfaces on resistor percolation.

Science.gov (United States)

Stenull, O; Janssen, H K; Oerding, K

2001-05-01

We study the effects of surfaces on resistor percolation at the instance of a semi-infinite geometry. Particularly we are interested in the average resistance between two connected ports located on the surface. Based on general grounds as symmetries and relevance we introduce a field theoretic Hamiltonian for semi-infinite random resistor networks. We show that the surface contributes to the average resistance only in terms of corrections to scaling. These corrections are governed by surface resistance exponents. We carry out renormalization-group improved perturbation calculations for the special and the ordinary transition. We calculate the surface resistance exponents phiS and phiS(infinity) for the special and the ordinary transition, respectively, to one-loop order.

Effects of surface and interface traps on exciton and multi-exciton dynamics in core/shell quantum dots

Science.gov (United States)

Bozio, Renato; Righetto, Marcello; Minotto, Alessandro

2017-08-01

Exciton interactions and dynamics are the most important factors determining the exceptional photophysical properties of semiconductor quantum dots (QDs). In particular, best performances have been obtained for ingeniously engineered core/shell QDs. We have studied two factors entering in the exciton decay dynamics with adverse effects for the luminescence efficiency: exciton trapping at surface and interface traps, and non-radiative Auger recombination in QDs carrying either net charges or multiple excitons. In this work, we present a detailed study into the optical absorption, fluorescence dynamics and quantum yield, as well as ultrafast transient absorption properties of CdSe/CdS, CdSe/Cd0.5Zn0.5S, and CdSe/ZnS QDs as a function of shell thickness. It turns out that de-trapping processes play a pivotal role in determining steady state emission properties. By studying the excitation dependent photoluminescence quantum yields (PLQY) in different CdSe/CdxZn1-xS (x = 0, 0.5, 1) QDs, we demonstrate the different role played by hot and cold carrier trapping rates in determining fluorescence quantum yields. Finally, the use of global analysis allows us untangling the complex ultrafast transient absorption signals. Smoothing of interface potential, together with effective surface passivation, appear to be crucial factors in slowing down both Auger-based and exciton trapping recombination processes.

The effects of size and surface modification of amorphous silica particles on biodistribution and liver metabolism in mice

International Nuclear Information System (INIS)

Lu, Xiaoyan; Ji, Cai; Jin, Tingting; Fan, Xiaohui

2015-01-01

Engineered nanoparticles, with unconventional properties, are promising platforms for biomedical applications. Since they may interact with a wide variety of biomolecules, it is critical to understand the impact of the physicochemical properties of engineered nanoparticles on biological systems. In this study, the effects of particle size and surface modification alone or in combination of amorphous silica particles (SPs) on biological responses were determined using a suite of general toxicological assessments and metabonomics analysis in mice model. Our results suggested that amino or carboxyl surface modification mitigated the liver toxicity of plain-surface SPs. 30 nm SPs with amino surface modification were found to be the most toxic SPs among all the surface-modified SP treatments at the same dosage. When treatment dose was increased, submicro-sized SPs with amino or carboxyl surface modification also induced liver toxicity. Biodistribution studies suggested that 70 nm SPs were mainly accumulated in liver and spleen regardless of surface modifications. Interestingly, these two organs exhibited different uptake trends. Furthermore, metabonomics studies indicated that surface modification plays a more dominant role to affect the liver metabolism than particle size. (paper)

Anomalous water dynamics at surfaces and interfaces: synergistic effects of confinement and surface interactions

Science.gov (United States)

Biswas, Rajib; Bagchi, Biman

2018-01-01

In nature, water is often found in contact with surfaces that are extended on the scale of molecule size but small on a macroscopic scale. Examples include lipid bilayers and reverse micelles as well as biomolecules like proteins, DNA and zeolites, to name a few. While the presence of surfaces and interfaces interrupts the continuous hydrogen bond network of liquid water, confinement on a mesoscopic scale introduces new features. Even when extended on a molecular scale, natural and biological surfaces often have features (like charge, hydrophobicity) that vary on the scale of the molecular diameter of water. As a result, many new and exotic features, which are not seen in the bulk, appear in the dynamics of water close to the surface. These different behaviors bear the signature of both water-surface interactions and of confinement. In other words, the altered properties are the result of the synergistic effects of surface-water interactions and confinement. Ultrafast spectroscopy, theoretical modeling and computer simulations together form powerful synergistic approaches towards an understanding of the properties of confined water in such systems as nanocavities, reverse micelles (RMs), water inside and outside biomolecules like proteins and DNA, and also between two hydrophobic walls. We shall review the experimental results and place them in the context of theory and simulations. For water confined within RMs, we discuss the possible interference effects propagating from opposite surfaces. Similar interference is found to give rise to an effective attractive force between two hydrophobic surfaces immersed and kept fixed at a separation of d, with the force showing an exponential dependence on this distance. For protein and DNA hydration, we shall examine a multitude of timescales that arise from frustration effects due to the inherent heterogeneity of these surfaces. We pay particular attention to the role of orientational correlations and modification of the

Children's expression through play therapy

Directory of Open Access Journals (Sweden)

Ljubomirović Nataša

2015-01-01

Full Text Available Play as a child's expression, is a skill through which children speaks to adults. Play therapy is a broad field of therapeutic intervention based on the play in order to help the child to cope with problems. Through play, children learn to communicate with others, to express their feelings. Through play they learn and can improve their cognitive, emotional and social capabilities. Play therapy is a nondirective technique focused on the child. It is not focused on the problem, at present even the past, but focused on the expression of the child feelings, accepting the child, rather than correction. The focus has been on the wisdom of a child, not on expertise therapists, guiding the child through play rather than instructing. The aim of play therapy is to encourage healthy growth and development, developing skills in problem solving, reduction of undesirable behavior, confidence building and the development of self-control. This method is effective for a wide range of children's problems, such as the state of stress, anxiety, problem behavior, hyperkinetic syndrome, depression, loss, trauma, the problem of bonding situations parents divorced, somatic disorders, autism spectrum disorders, social problems.

Surface effects on the mechanical properties of nanoporous materials

International Nuclear Information System (INIS)

Lu Zixing; Zhang Cungang; Liu Qiang; Yang Zhenyu

2011-01-01

In this paper, surface effects on the mechanical behaviour of nanoporous materials are investigated using the theory of surface elasticity and Timoshenko beam theory based on the tetrakaidecahedron (or Kelvin) open-cell foam model. Meanwhile, the influence of surface elasticity and residual surface stress on the mechanical properties of nanoporous materials is discussed. In addition, the results derived from the theory of Euler-Bernoulli beam model are also provided for comparison. Theoretical results show that the effective Young's modulus of the nanoporous materials increases as the diameter of the strut decreases, but in contrast Poisson's ratio and the brittle collapse strength decrease with the diameter of the strut. The contribution of shear deformation to surface effects on elastic properties is more significant, while the surface effects on brittle collapse strength are not sensitive to shear deformation, and it can even be neglected. As the strut size increases, the present results can be reduced to the cases without considering surface effects, which verifies the efficiency of the present model to a certain extent.

Effectiveness of Client-centered Play Therapy on Fear and Anxiety in Preschool Children

Directory of Open Access Journals (Sweden)

Hoda Sadat Mosavi

2016-12-01

Full Text Available Background and Objective: Preschool period is playing main role in development and adjustment of children. Fear and anxiety are of externalizing disorders, providing untreated it leads to negative effects on individual and social relationship specially in adulthood therefore, this research investigates the influence of client-centered play therapy on fear and anxiety among preschool children (5-6 aged.Materials and Methods: This study is a quasi-experimental study with pre and post- tests. 14 male and female preschool children (5-6 aged who were obtaining scores higher than cut-off in Spence anxiety scale (SAS and fear survey schedule for children-revised (FSSC-R parents’ form questionnaires were selected, and then they were assigned randomly to the control and experimental groups. The experimental group received techniques of client-centered play therapy for six treatment sessions (45minutes for each session. The fear and anxiety were measured at the beginning and at end of therapeutic session, utilizing the Spence Children's Anxiety Scale and fear survey schedule for children-revised (FSSC-R parents’ form. Statistical analysis conducted by analysis of covariance (ANCOVA.Results: There is significantly difference in Mean (SD scores of pretest 130.4 (3.3 and posttest 127.1 (4.6 fear (P<0.001, F= 24.6 and in scores of pretest 58.6 (2.6 and post-test 48.28 (3.6 anxiety (P<0.001, F=19.5 between preschool children in pre and post-test.Conclusion: Findings indicated that client-centered play therapy has effective in reducing behavioral problem such as fear and anxiety disorders in preschool children. Therefore, it can be useful and applicable as the psychological therapeutic interventions for decreasing behavioral distress in children.

Why People Play: Artificial Lives Acquiring Play Instinct to Stabilize Productivity

Directory of Open Access Journals (Sweden)

Shinichi Tamura

2012-01-01

Full Text Available We propose a model to generate a group of artificial lives capable of coping with various environments which is equivalent to a set of requested task, and likely to show that the plays or hobbies are necessary for the group of individuals to maintain the coping capability with various changes of the environment as a whole. This may be an another side of saying that the wide variety of the abilities in the group is necessary, and if the variety in a species decreased, its species will be extinguished. Thus, we show some simulation results, for example, in the world where more variety of abilities are requested in the plays, performance of the whole world becomes stable and improved in spite of being calculated only from job tasks, and can avoid the risk of extinction of the species. This is the good effect of the play.

Effects of Ce concentrations on ignition temperature and surface tension of Mg-9wt.%Al alloy

Directory of Open Access Journals (Sweden)

Deng Zhenghua

2013-03-01

Full Text Available Magnesium alloys are well known for their excellent properties, but the potential issues with oxidation and burning during melting and casting largely limit its industrial applications. The addition of Ce in magnesium alloys can significantly raise ignition-proof performance and change the structure of the oxide film on the surface of the molten metal as well as the surface tension values. Surface tension is an important physical parameter of the metal melts, and it plays an important role in the formation of surface oxide film. In this present work, the ignition temperature and the surface tension of Mg-9wt.%Al alloy with different Ce concentrations were studied. Surface tensions was measured using the maximum bubble pressure method (MBPM. Ignition temperature was measured using NiCr-NiSi type thermocouples and was monitored and recorded via a WXT-604 desk recording device. The results show that the ignition point of Mg-9wt.%Al alloy can be effectively elevated by adding Ce. The ignition temperature reaches its highest point of 720 ℃ when the addition of Ce is 1wt.%. The surface tension of the molten Mg-9wt.%Al alloy decreases exponentially with the increase of Ce addition at the same temperature. Similarly, the experiment also shows that the surface tension of Mg-9wt.%Al alloy decreases exponentially with the increase of temperature.

Adsorption effectiveness of β-lactoglobulin onto gold surface determined by quartz crystal microbalance.

Science.gov (United States)

Jachimska, B; Świątek, S; Loch, J I; Lewiński, K; Luxbacher, T

2018-06-01

Bovine β-lactoglobulin (LGB) is a transport protein that can bind to its structure hydrophobic bioactive molecules. Due to the lack of toxicity, high stability and pH-dependent molecular binding mechanism, lactoglobulin can be used as a carrier of sparingly soluble drugs. Dynamic light scattering has confirmed LGB's tendency to create oligomeric forms. The hydrodynamic diameter of LGB molecules varies from 4 nm to 6 nm in the pH range of 2-10 and ionic strength I = 0.001-0.15 M, which corresponds to the presence of mono or dimeric LGB forms. The LGB zeta potential varies from 26.5 mV to -33.3 mV for I = 0.01 M and from 13.3 mV to -16 mV for I = 0.15 M in the pH range of 2-10. The isoelectric point is at pH 4.8. As a result of strong surface charge compensation, the maximum effective ionization degree of the LGB molecule is 35% for ionic strength I = 0.01 M and 22% for I = 0.15 M. The effectiveness of adsorption is linked with the properties of the protein, as well as those of the adsorption surface. The functionalization of gold surfaces with β-lactoglobulin (LGB) was studied using a quartz crystal microbalance with energy dissipation monitoring (QCM-D). The effectiveness of LGB adsorption correlates strongly with a charge of gold surface and the zeta potential of the molecule. The greatest value of the adsorbed mass was observed in the pH range in which LGB has a positive zeta potential values, below pH 4.8. This observation shows that electrostatic interactions play a dominant role in LGB adsorption on gold surfaces. Based on the adsorbed mass, protein orientation on gold surfaces was determined. The preferential side-on orientation of LGB molecules observed in the adsorption layer is consistent with the direction of the molecule dipole momentum determined by molecular dynamics simulations of the protein (MD). The use of the QCM-D method also allowed us to determine the effectiveness of adsorption of LGB on gold

Block Play and Mathematics Learning in Preschool: The Effects of Building Complexity, Peer and Teacher Interactions in the Block Area, and Replica Play Materials

Science.gov (United States)

Trawick-Smith, Jeffrey; Swaminathan, Sudha; Baton, Brooke; Danieluk, Courtney; Marsh, Samantha; Szarwacki, Monika

2017-01-01

Block play has been included in early childhood classrooms for over a century, yet few studies have examined its effects on learning. Several previous investigations indicate that the complexity of block building is associated with math ability, but these studies were often conducted in adult-guided, laboratory settings. In the present…

NHE8 plays important roles in gastric mucosal protection

Science.gov (United States)

Xu, Hua; Li, Jing; Chen, Huacong; Wang, Chunhui

2013-01-01

Sodium/hydrogen exchanger (NHE) 8 is an apically expressed membrane protein in the intestinal epithelial cells. It plays important roles in sodium absorption and bicarbonate secretion in the intestine. Although NHE8 mRNA has been detected in the stomach, the precise location and physiological role of NHE8 in the gastric glands remain unclear. In the current study, we successfully detected the expression of NHE8 in the glandular region of the stomach by Western blotting and located NHE8 protein at the apical membrane in the surface mucous cells by a confocal microscopic method. We also identified the expression of downregulated-in-adenoma (DRA) in the surface mucous cells in the stomach. Using NHE8−/− mice, we found that NHE8 plays little or no role in basal gastric acid production, yet NHE8−/− mice have reduced gastric mucosal surface pH and higher incidence of developing gastric ulcer. DRA expression was reduced significantly in the stomach in NHE8−/− mice. The propensity for gastric ulcer, reduced mucosal surface pH, and low DRA expression suggest that NHE8 is indirectly involved in gastric bicarbonate secretion and gastric mucosal protection. PMID:23220221

Why do adult dogs 'play'?

Science.gov (United States)

Bradshaw, John W S; Pullen, Anne J; Rooney, Nicola J

2015-01-01

Among the Carnivora, play behaviour is usually made up of motor patterns characteristic of predatory, agonistic and courtship behaviour. Domestic dogs are unusual in that play is routinely performed by adults, both socially, with conspecifics and with humans, and also asocially, with objects. This enhanced playfulness is commonly thought to be a side effect of paedomorphosis, the perpetuation of juvenile traits into adulthood, but here we suggest that the functions of the different types of play are sufficiently distinct that they are unlikely to have arisen through a single evolutionary mechanism. Solitary play with objects appears to be derived from predatory behaviour: preferred toys are those that can be dismembered, and a complex habituation-like feedback system inhibits play with objects that are resistant to alteration. Intraspecific social play is structurally different from interspecific play and may therefore be motivationally distinct and serve different goals; for example, dogs often compete over objects when playing with other dogs, but are usually more cooperative when the play partner is human. The majority of dogs do not seem to regard competitive games played with a human partner as "dominance" contests: rather, winning possession of objects during games appears to be simply rewarding. Play may be an important factor in sociality, since dogs are capable of extracting social information not only from games in which they participate, but also from games that they observe between third parties. We suggest that the domestic dog's characteristic playfulness in social contexts is an adaptive trait, selected during domestication to facilitate both training for specific purposes, and the formation of emotionally-based bonds between dog and owner. Play frequency and form may therefore be an indicator of the quality of dog-owner relationships. Copyright © 2014 Elsevier B.V. All rights reserved.

Size effect of the elastic modulus of rectangular nanobeams: Surface elasticity effect

International Nuclear Information System (INIS)

Yao Hai-Yan; Fan Wen-Liang; Yun Guo-Hong

2013-01-01

The size-dependent elastic property of rectangular nanobeams (nanowires or nanoplates) induced by the surface elasticity effect is investigated by using a developed modified core-shell model. The effect of surface elasticity on the elastic modulus of nanobeams can be characterized by two surface related parameters, i.e., inhomogeneous degree constant and surface layer thickness. The analytical results show that the elastic modulus of the rectangular nanobeam exhibits a distinct size effect when its characteristic size reduces below 100 nm. It is also found that the theoretical results calculated by a modified core-shell model have more obvious advantages than those by other models (core-shell model and core-surface model) by comparing them with relevant experimental measurements and computational results, especially when the dimensions of nanostructures reduce to a few tens of nanometers. (condensed matter: structural, mechanical, and thermal properties)

Video Games and Aggression: the effects of violent game play on self-reported and peer-observed anger

OpenAIRE

Nelson, Andrew R

2009-01-01

The continued upsurge in the popularity of video games has lead to persistent debate over the effects of play, particularly the use of violent video games. The present experimental study aimed to replicate the results of numerous research groups who found that playing violent video games lead to an increase in aggression and to examine peer-observer perceptions of violent game play. Two experiments were carried out; the first used 24 participants in a within-subjects design being filmed while...

Effects of playing video games on perceptions of one's humanity.

Science.gov (United States)

Greitemeyer, Tobias

2013-01-01

According to self-perception theory, individuals infer their characteristics by observing their own behavior. In the present research, the hypothesis is examined whether helping behavior increases perceptions of one's own humanity even when help is given that does not benefit a real person. In fact, two studies revealed that playing a prosocial video game (where the goal is to help and care for other game characters) led to increased perceptions of the player's own humanity (in particular, for positive humanity traits). Results also revealed that playing a violent, relative to a neutral, video game decreased perceptions of humanity on positive humanity traits and increased perceptions of humanity on negative humanity traits. Taken together, it appears that being helpful while playing video games leads to the perception of being more human, whereas being harmful while playing video games leads players to perceive themselves negatively.

Effects of Playing a Serious Computer Game on Body Mass Index and Nutrition Knowledge in Women.

Science.gov (United States)

Shiyko, Mariya; Hallinan, Sean; Seif El-Nasr, Magy; Subramanian, Shree; Castaneda-Sceppa, Carmen

2016-06-02

Obesity and weight gain is a critical public health concern. Serious digital games are gaining popularity in the context of health interventions. They use persuasive and fun design features to engage users in health-related behaviors in a non-game context. As a young field, research about effectiveness and acceptability of such games for weight loss is sparse. The goal of this study was to evaluate real-world play patterns of SpaPlay and its impact on body mass index (BMI) and nutritional knowledge. SpaPlay is a computer game designed to help women adopt healthier dietary and exercise behaviors, developed based on Self-Determination theory and the Player Experience of Need Satisfaction (PENS) model. Progress in the game is tied to real-life activities (e.g., eating a healthy snack, taking a flight of stairs). We recruited 47 women to partake in a within-subject 90-day longitudinal study, with assessments taken at baseline, 1-, 2-, and 3- months. Women were on average, 29.8 years old (±7.3), highly educated (80.9% had BA or higher), 39% non-White, baseline BMI 26.98 (±5.6), who reported at least contemplating making changes in their diet and exercise routine based on the Stages of Change Model. We computed 9 indices from game utilization data to evaluate game play. We used general linear models to examine inter-individual differences between levels of play, and multilevel models to assess temporal changes in BMI and nutritional knowledge. Patterns of game play were mixed. Participants who reported being in the preparation or action stages of behavior change exhibited more days of play and more play regularity compared to those who were in the contemplation stage. Additionally, women who reported playing video games 1-2 hours per session demonstrated more sparse game play. Brief activities, such as one-time actions related to physical activity or healthy food, were preferred over activities that require a longer commitment (e.g., taking stairs every day for a week

Play and playfulness, basic features of early childhood education

NARCIS (Netherlands)

Singer, E.

2013-01-01

This article argues that play and playfulness are basic features in early childhood education, but that play curricula can have serious drawbacks. The starting point is the play theory of the Dutch historian Johan Huizinga, a radical critic of the focus on the educational benefits of play. According

Play and playfulness in early childhood education and care.

Directory of Open Access Journals (Sweden)

Singer E.

2015-06-01

Full Text Available Play and playfulness are basic features in early childhood education. The elements of play are pleasure, a sense of freedom, and the co-construction of shared meaning through the use of rules or rhythms. Play and learning are closely related in early childhood. But when the focus on the educational benefits of play becomes too strong, the most essential feature of play is lost: children’s pleasure. Young children in group settings often have to adapt to the teachers’ demands related to security, hygiene, and social norms and values. But the playfulness of the teachers helps to overcome differences in power in the caregiver-child relationship and prevents young children from becoming overburdened with strict rules and group discipline. Play and playfulness are a resource of shared pleasure and creativity in learning processes.

Effects of Behavioral Contingencies on Adolescent Active Videogame Play and Overall Activity: A Randomized Trial.

Science.gov (United States)

Norman, Gregory J; Adams, Marc A; Ramirez, Ernesto R; Carlson, Jordan A; Kerr, Jacqueline; Godbole, Suneeta; Dillon, Lindsay; Marshall, Simon J

2013-06-01

This study evaluated the effect of four active videogames (AVGs) varying in behavioral contingencies (behavior-consequence relations) on adolescent AVG play and overall activity levels over 4 weeks. Each AVG, manufactured by SSD/Xavix(®) (Shiseido Co. of Japan, Tokyo, Japan), was coded and scored for the number of positive and aversive behavioral contingencies within the games. "Bowling" and "Tennis" were classified as having "higher contingency scores," and "Boxing" and aerobic fitness training were classified as having "lower contingency scores." Adolescents (n=63; 11-15 years old; 62% male; 38% Hispanic; 44% overweight or obese) were randomized to play one of the four AVGs at home and recorded game play sessions in a paper log. Baseline and week 4 assessments were completed at home; week 1, 2, and 3 assessments were completed by telephone. Accelerometers were worn during baseline and weeks 1 and 4. Accelerometer-measured sedentary and light activity hours/day were stable over time, whereas moderate-vigorous physical activity minutes/day increased in the higher contingency group and decreased in the lower contingency group (interaction effect, 6.43, P=0.024). Reported game play minutes decreased in both groups from week 1 to week 4 (-29.42 minutes, P=0.001). There was some support for the hypothesis that AVGs with more behavioral contingencies, compared with AVGs with fewer behavioral contingencies, result in more physical activity. However, overall AVG play decreased substantially after the first week. Further study is needed to better understand how behavioral contingencies can be used in AVGs to enhance their potential to provide health benefits to game players.

Playful Membership

DEFF Research Database (Denmark)

Åkerstrøm Andersen, Niels; Pors, Justine Grønbæk

2014-01-01

This article studies the implications of current attempts by organizations to adapt to a world of constant change by introducing the notion of playful organizational membership. To this end we conduct a brief semantic history of organizational play and argue that when organizations play, employees...... are expected to engage in playful exploration of alternative selves. Drawing on Niklas Luhmann's theory of time and decision-making and Gregory Bateson's theory of play, the article analyses three empirical examples of how games play with conceptions of time. We explore how games represent an organizational...

Effects of ion sputtering on semiconductor surfaces

International Nuclear Information System (INIS)

McGuire, G.E.

1978-01-01

Ion beam sputtering has been combined with Auger spectroscopy to study the effects of ion beams on semiconductor surfaces. Observations on the mass dependence of ion selective sputtering of two component systems are presented. The effects of ion implantation are explained in terms of atomic dilution. Experimental data are presented that illustrate the super-position of selective sputtering and implantation effects on the surface composition. Sample reduction from electron and ion beam interaction is illustrated. Apparent sample changes which one might observe from the effects of residual gas contamination and electric fields are also discussed. (Auth.)

Facilitating Social Play for Children with PDDs: Effects of Paired Robotic Devices

Directory of Open Access Journals (Sweden)

Soichiro Matsuda

2017-06-01

Full Text Available Interacting with toys and other people is fundamental for developing social communication skills. However, children with autism spectrum disorder (ASD are characterized by having a significant impairment in social interaction, which often leads to deficits in play skills. For this reason, methods of teaching play skills to young children with ASD have been well documented. Although previous studies have examined a variety of instructional strategies for teaching skills, few studies have evaluated the potential of using robotic devices. The purpose of the present study is to examine whether automatic feedback provided by colored lights and vibration via paired robotic devices, COLOLO, facilitates social play behaviors in children with ASD. We also explore how social play relates to social interaction. COLOLO is a system of paired spherical devices covered with soft fabric. All participants in this study were recruited as volunteers through the Department of Psychology at Keio University. The pilot study included three participants diagnosed with Pervasive Developmental Disorders (PDDs; 5- to 6-year-old boys, and compared experimental conditions with and without automatic feedback from the devices (colored lights and vibration. The results indicated that the participants in the condition that included feedback from the devices exhibited increased rates of ball contact and looking at the therapist’s ball, but did not exhibit increased rates of eye contact or positive affect. In the experimental study, a systematic replication of the pilot study was performed with three other participants diagnosed with PDDs (3- to 6-year-old boys, using an A-B-A-B design. Again, the results demonstrated that, in the condition with colored lights and vibration, the children increased ball contact as well as looking at the therapist’s ball. However, the results did not show the effect of automatic feedback consistently for three children. These findings are

Teaching Play Skills to Visually Impaired Preschool Children: Its Effect on Social Interaction

Science.gov (United States)

Ozaydin, Latife

2015-01-01

The aim of this study is to assess the effects that teaching visually impaired (VI) preschool children play skills has on their abilities to initialize and respond to social interactions with their typically developing (TD) peers in a reverse mainstreaming preschool class. The subjects of the study were three female VI students regularly attending…

Effect of increase in allotted time on game playing performance: Case study of an online word game

OpenAIRE

Putthiwanit, Chutinon; Kincart, Andrew

2011-01-01

Online game players tend to differ in the duration of time they play. However, no matter whether the time on playing an online game is spent positively or negatively, we may assume that when the duration of each online-game round is increased, players tend to engage in more interaction with their opponents. Though there are a significant number of research studies on time usage in computer games, there is no research exploring the direct effect of time on online game playing performance. As a...

Effects of surface and interface scattering on anomalous Hall effect in Co/Pd multilayers

KAUST Repository

Guo, Zaibing

2012-09-27

In this paper, we report the results of surface and interface scattering on anomalous Hall effect in Co/Pd multilayers with perpendicular magnetic anisotropy. The surface scattering effect has been extracted from the total anomalous Hall effect. By scaling surface scattering contribution with ρAHs∼ργss, the exponent γ has been found to decrease with the increase of surface scattering resistivity, which could account for the thickness-dependent anomalous Hall effect. Interface diffusion induced by rapid thermal annealing modifies not only the magnetization and longitudinal resistivity but also the anomalous Hall effect; a large exponent γ ∼ 5.7 has been attributed to interface scattering-dominated anomalous Hall effect.

Surface excitation parameter for rough surfaces

International Nuclear Information System (INIS)

Da, Bo; Salma, Khanam; Ji, Hui; Mao, Shifeng; Zhang, Guanghui; Wang, Xiaoping; Ding, Zejun

2015-01-01

Graphical abstract: - Highlights: • Instead of providing a general mathematical model of roughness, we directly use a finite element triangle mesh method to build a fully 3D rough surface from the practical sample. • The surface plasmon excitation can be introduced to the realistic sample surface by dielectric response theory and finite element method. • We found that SEP calculated based on ideal plane surface model are still reliable for real sample surface with common roughness. - Abstract: In order to assess quantitatively the importance of surface excitation effect in surface electron spectroscopy measurement, surface excitation parameter (SEP) has been introduced to describe the surface excitation probability as an average number of surface excitations that electrons can undergo when they move through solid surface either in incoming or outgoing directions. Meanwhile, surface roughness is an inevitable issue in experiments particularly when the sample surface is cleaned with ion beam bombardment. Surface roughness alters not only the electron elastic peak intensity but also the surface excitation intensity. However, almost all of the popular theoretical models for determining SEP are based on ideal plane surface approximation. In order to figure out whether this approximation is efficient or not for SEP calculation and the scope of this assumption, we proposed a new way to determine the SEP for a rough surface by a Monte Carlo simulation of electron scattering process near to a realistic rough surface, which is modeled by a finite element analysis method according to AFM image. The elastic peak intensity is calculated for different electron incident and emission angles. Assuming surface excitations obey the Poisson distribution the SEPs corrected for surface roughness are then obtained by analyzing the elastic peak intensity for several materials and for different incident and emission angles. It is found that the surface roughness only plays an

Surface and interface effects in VLSI

CERN Document Server

Einspruch, Norman G

1985-01-01

VLSI Electronics Microstructure Science, Volume 10: Surface and Interface Effects in VLSI provides the advances made in the science of semiconductor surface and interface as they relate to electronics. This volume aims to provide a better understanding and control of surface and interface related properties. The book begins with an introductory chapter on the intimate link between interfaces and devices. The book is then divided into two parts. The first part covers the chemical and geometric structures of prototypical VLSI interfaces. Subjects detailed include, the technologically most import

Effects of surface deposition and droplet injection on film cooling

International Nuclear Information System (INIS)

Wang, Jin; Cui, Pei; Vujanović, Milan; Baleta, Jakov; Duić, Neven; Guzović, Zvonimir

2016-01-01

Highlights: • Cooling effectiveness is significantly affected by the deposition size. • Coverage area for model without mist is reduced by increasing the deposition height. • Wall temperature is decreased by 15% with 2% mist injection. • Cooling coverage is increased by more than three times with 2% mist injection. • Cooling effectiveness for mist models is improved by increasing deposition height. - Abstract: In the present research, the influence of the particle dispersion onto the continuous phase in film cooling application was analysed by means of numerical simulations. The interaction between the water droplets and the main stream plays an important role in the results. The prediction of two-phase flow is investigated by employing the discrete phase model (DPM). The results present heat transfer characteristics in the near-wall region under the influence of mist cooling. The local wall temperature distribution and film cooling effectiveness are obtained, and results show that the film cooling characteristics on the downstream wall are affected by different height of surface deposits. It is also found that smaller deposits without mist injection provide a lower wall temperature and a better cooling performance. With 2% mist injection, evaporation of water droplets improves film cooling effectiveness, and higher deposits cause lateral and downstream spread of water droplets. The results indicate that mist injection can significantly enhance film cooling performance.

THE MAGIC OF PLAY: LOW-INCOME MOTHERS' AND FATHERS' PLAYFULNESS AND CHILDREN'S EMOTION REGULATION AND VOCABULARY SKILLS.

Science.gov (United States)

Cabrera, Natasha J; Karberg, Elizabeth; Malin, Jenessa L; Aldoney, Daniela

2017-11-01

Using data from a diverse sample of low-income families who participated in the Early Head Start Research Evaluation Project (n = 73), we explored the association between mothers' and fathers' playfulness with toddlers, toddler's affect during play, and children's language and emotion regulation at prekindergarten. There were two main findings. First, fathers' playfulness in toddlerhood was associated with children's vocabulary skills in prekindergarten whereas mothers' playfulness was related to children's emotion regulation. Cross-parental effects were found only for mothers. The association between mothers' playfulness and children's vocabulary and emotion regulation was strengthened when fathers engaged in more pretend play and when children were affectively positive during the play. These findings show that playfulness is an important source of variation in the vocabulary and emotion regulation of children growing up in low-income families. They also point to domain-specific ways that mothers and fathers promote children's regulatory and vocabulary skills, and highlight the importance of children's positive engagement in play. © 2017 Michigan Association for Infant Mental Health.

Moving educational role-play beyond entertainment

DEFF Research Database (Denmark)

Duus Henriksen, Thomas

2010-01-01

Educational role-play has long proved an effective tool for consultants trying to develop the skills that employees are using for performing certain job functions. However, while educational role-play often is presented as an entertaining means for learning, such insistence on making learning gam...

Influence of surface topography on the surface durability of steam oxidised sintered iron

Directory of Open Access Journals (Sweden)

José Daniel Biasoli de Mello

2005-06-01

Full Text Available Durability of surfaces has been reported as the main factor affecting tribological behavior of steam oxidised sintered iron. The presence of surface pores and their negative influence on load bearing capacity, suggest that surface topography might play an important role on the durability of the oxide layer. In this paper, the influence of compaction pressure and powder grade on surface topography, and as a consequence, its effect on the tribological behavior of steam oxidised sintered iron has been analysed. Specimens prepared from atomised iron powders with different sizes were compacted using 4 different pressures, sintered, and then subjected to steam treatment. Tribological characterisation was carried out in a reciprocating sliding wear test. Although the processing parameters affected the surface topography to a considerable extent, the main influence may be attributed to powder grade. A strong influence of surface topography on the durability distance, evaluated in terms of the evolution of contact resistance with total sliding distance, has been highlighted. Surfaces which were smoother and had high load-carrying capacity were always associated with a higher durability distance.

Modeling of surface tension effects in venturi scrubbing

Science.gov (United States)

Ott, Robert M.; Wu, Tatsu K. L.; Crowder, Jerry W.

A modified model of venturi scrubber performance has been developed that addresses two effects of liquid surface tension: its effect on droplet size and its effect on particle penetration into the droplet. The predictions of the model indicate that, in general, collection efficiency increases with a decrease in liquid surface tension, but the range over which this increase is significant depends on the particle size and on the scrubber operating parameters. The predictions further indicate that the increases in collection efficiency are almost totally due to the effect of liquid surface tension on the mean droplet size, and that the collection efficiency is not significantly affected by the ability of the particle to penetrate the droplet.

Effects of realism on extended violent and nonviolent video game play on aggressive thoughts, feelings, and physiological arousal.

Science.gov (United States)

Barlett, Christopher P; Rodeheffer, Christopher

2009-01-01

Previous research has shown that playing violent video game exposure can increase aggressive thoughts, aggressive feelings, and physiological arousal. This study compared the effects that playing a realistic violent, unrealistic violent, or nonviolent video game for 45 min has on such variables. For the purpose of this study, realism was defined as the probability of seeing an event in real life. Participants (N=74; 39 male, 35 female) played either a realistic violent, unrealistic violent, or nonviolent video game for 45 min. Aggressive thoughts and aggressive feelings were measured four times (every 15 min), whereas arousal was measured continuously. The results showed that, though playing any violent game stimulated aggressive thoughts, playing a more realistic violent game stimulated significantly more aggressive feelings and arousal over the course of play. Copyright 2009 Wiley-Liss, Inc.

The acute effect of match play on hamstring strength and lower limb flexibility in elite youth football players

DEFF Research Database (Denmark)

Wollin, M; Thorborg, K; Pizzari, T

2017-01-01

. Competitive football match play has a significant acute and transient effect on isometric hamstring strength and associated pain levels during resisted knee flexion in male international youth players. Range of motion measures appear to remain relatively unaffected by match play. Isometric hamstring strength......The aim of this study was to investigate the effect of competitive football match play on hamstring strength and lower limb flexibility. Fifteen male international youth football players were included. Hamstring strength and associated pain ratings, ankle dorsiflexion, hip extension, knee extension...... and flexion range of motion were evaluated immediately post-match and at intervals of 24, 48, and 72 h post-match. Strength significantly reduced post-match (P

The effect of two kinds of role playing on self-evaluation of improved assertiveness.

Science.gov (United States)

Kipper, D A

1992-03-01

The study investigated the "differential effect of role-playing enactments" hypothesis through self-evaluations of improvement in assertiveness by participants in an assertive training program. Twenty-two nonassertive Israeli students were trained in two groups: mimetic-replications (action modeling, n = 12) and spontaneous (self-produced action, n = 10) role-playing interventions. Comparisons of their scores on the Self-Expression College Scale (CSES) before and after the training showed that both groups significantly improved their self-evaluations, but the mimetic-replication group did better. In particular, this group scored significantly higher on the CSES first factor (the willingness to take risks in situations that involved other, significant persons).

Effects of surface treatments on microstructure in stainless steel

International Nuclear Information System (INIS)

Mabuchi, Yasuhiro; Tamako, Hiroaki; Kaneda, Junya; Yamashita, Norimichi; Miyakawa, Masahiko

2009-01-01

It is revealed that Stress Corrosion Cracking (SCC) on the surface of the L-grade stainless steels in Nuclear Power Plants is caused by heavily cold work of the materials. The microstructure, hardness and residual stress on the surface of the material are factors for SCC initiation. There are surface treatment methods that is effective reduction on SCC such as Flap Wheel (FW) polishing, Clean N Strip (CNS) polishing, Water Jet Peening (WJP) and Shot Peening (SP). In this paper, the characteristics of the surface cold worked layer of the L-grade stainless steels conducted by above-mentioned surface treatments are analyzed, and effects of the surface treatments on the surface layer are discussed. (author)

The effect of group play therapy on social-emotional skills in pre-school children.

Science.gov (United States)

Chinekesh, Ahdieh; Kamalian, Mehrnoush; Eltemasi, Masoumeh; Chinekesh, Shirin; Alavi, Manijeh

2013-12-24

Childhood is important and critical period in human life. The foundation of ego is shaped in childhood. Play therapy is one of the successful strategies to help children with inner conflicts problems. This method of psychotherapy is base on the normal learning processes of children, provides solutions to relieve feelings of stress, and expands self-expression. Group play therapy can enhance the self-awareness, self- regulation, social communication, empathy and adoptability in children. Present study investigated the effects of play therapy on relational and emotional skills of pre-school children. For this purpose, the total numbers of 372 pre-school children were randomly selected, and divided into two equal groups (case and control). In next step, the BUSSE-SR methodology was used for evaluation and comparison of self-awareness, self-regulation, social interaction, empathy, adoptability, and control groups. Pre-test were performed for both groups and case group was involved in-group play therapy. According to the results of post-test, correlation of variables between case-control groups was examined by multivariate analysis of covariance. Frequency of boys and girls in our sample were 51.3 and 48.7 percent, respectively. The mean age of children was 5.1±0.6 year. According to the results of present study, play therapy significantly enhanced the social-emotional skills (Pplay therapy can be used in pre-school centers to help children learn problem-solving skills and communicate with others.

Effects of "Fair Play Game" Strategy on Moderate to Vigorous Physical Activity in Physical Education

Science.gov (United States)

Azevedo, Liane B.; Vidoni, Carla; Dinsdale, Sarah

2016-01-01

Less than 50% of a PE lesson is usually spent in MVPA. A dependent-group contingency strategy, "Fair Play Game," has shown effectiveness in increasing MVPA during PE lessons among students from affluent schools. The purpose of this study was to determine the effectiveness of this strategy on MVPA among students from an undeserved…

Adolescent opiate exposure in the female rat induces subtle alterations in maternal care and transgenerational effects on play behavior.

Directory of Open Access Journals (Sweden)

Nicole L. Johnson

2011-06-01

Full Text Available The non-medical use of prescription opiates, such as Vicodin® and MSContin®, has increased dramatically over the past decade. Of particular concern is the rising popularity of these drugs in adolescent female populations. Use during this critical developmental period could have significant long-term consequences for both the female user as well as potential effects on her future offspring. To address this issue, we have begun modeling adolescent opiate exposure in female rats and have observed significant transgenerational effects despite the fact that all drugs are withdrawn several weeks prior to pregnancy. The purpose of the current set of studies was to determine whether adolescent morphine exposure modifies postpartum care. In addition, we also examined juvenile play behavior in both male and female offspring. The choice of the social play paradigm was based on previous findings demonstrating effects of both postpartum care and opioid activity on play behavior. The findings revealed subtle modifications in the maternal behavior of adolescent morphine-exposed females, primarily related to the amount of time females’ spend nursing and in non-nursing contact with their young. In addition, male offspring of adolescent morphine-exposed mothers (MOR-F1 demonstrate decreased rough and tumble play behaviors, with no significant differences in general social behaviors (i.e. social grooming and social exploration. Moreover, there was a tendency toward increased rough and tumble play in MOR-F1 females, demonstrating the sex-specific nature of these effects. Given the importance of the postpartum environment on neurodevelopment, it is possible that modifications in maternal-offspring interactions, related to a history of adolescent opiate exposure, plays a role in the observed transgenerational effects. Overall, these studies indicate that the long-term consequences of adolescent opiate exposure can impact both the female and her future offspring.

How passion and impulsivity influence a player's choice of videogame, intensity of playing and time spent playing

OpenAIRE

Puerta-Cortés, Diana Ximena; Panova, Tayana; Carbonell, Xavier; Chamarro, Andrés

2016-01-01

Videogames have received much attention in addiction research due to their popularity and frequent use. However, few studies have addressed the effect of passion and impulsivity in gamers. Therefore, the aim of the current study was to examine the influence of passion and impulsivity on the intensity of play, playing time, and choice of Massive Multiplayer Online Role Play Game (MMORPG) vs. non-MMORPG. A sample of 630 university students (40.7% Colombian, 59.3% Spanish) responded ...

The effect of sub-minimum inhibitory concentration of ciprofloxacin concentrations on enteroaggregative Escherichia coli and the role of the surface protein dispersin

Energy Technology Data Exchange (ETDEWEB)

Mortensen, Ninell P [ORNL; Fowlkes, Jason Davidson [ORNL; Trevino-Dopatka, Sonia [ORNL; Maggart, Michael J [ORNL; Boisen, Nadia [University of Virginia School of Medicine; Doktycz, Mitchel John [ORNL; Nataro, James [University of Virginia School of Medicine; Allison, David P [ORNL

2011-01-01

Enteroaggregative Escherichia coli (EAEC) are bacterial pathogens that cause watery diarrhea, which is often persistent and can be inflammatory. The antibiotic ciprofloxacin is used to treat EAEC infections, but a full understanding of the antimicrobial effects of ciprofloxacin is needed for more efficient treatment of bacterial infections. In this study, it was found that sub-minimum inhibitory concentrations (sub-MICs) of ciprofloxacin had an inhibitory effect on EAEC adhesion to glass and mammalian HEp-2 cells. It was also observed that bacterial surface properties play an important role in bacterial sensitivity to ciprofloxacin. In an EAEC mutant strain where the hydrophobic positively charged surface protein dispersin was absent, sensitivity to ciprofloxacin was reduced compared with the wild-type strain. Identified here are several antimicrobial effects of ciprofloxacin at sub-MIC concentrations indicating that bacterial surface hydrophobicity affects the response to ciprofloxacin. Investigating the effects of sub-MIC doses of antibiotics on targeted bacteria could help to further our understanding of bacterial pathogenicity and elucidate future antibiotic treatment modalities.

Word Play: Scaffolding Language Development through Child-Directed Play

Science.gov (United States)

Wasik, Barbara A.; Jacobi-Vessels, Jill L.

2017-01-01

Play is an important activity in young children's lives. It is how children explore their world and build knowledge. Although free play, which is play that is totally child directed, contributes to children's learning, self-regulation and motivation, adults' participation in children's play is critical in their development, especially their…

Bioactive glass-chitosan composite coatings on PEEK: Effects of surface wettability and roughness on the interfacial fracture resistance and in vitro cell response

Science.gov (United States)

Hong, Wei; Guo, Fangwei; Chen, Jianwei; Wang, Xin; Zhao, Xiaofeng; Xiao, Ping

2018-05-01

To improve the osteointegration of polyetheretherketone (PEEK) spinal fusions, the 45S5 bioactive glass® (BG)-chitosan (CH) composite was used to coat the PEEK by a dip-coating method at room temperature. A robust bonding between the BG-CH composite coating and the PEEK was achieved by a combined surface treatment of sand blasting and acid etching. The effects of surface wettability and surface roughness on the adhesion of the BG-CH composite coating were characterized by fracture resistance (Gc), respectively, measured by four-point bending tests. Compared with the surface polar energy (wettability), the surface roughness (>3 μm) played a more important role for the increase in Gc values by means of crack shielding effect under the mixed mode stress. The maximum adhesion strength (σ) of the coatings on the modified PEEK measured by the tensile pull-off test was about 5.73 MPa. The in vitro biocompatibilities of PEEK, including cell adhesion, cell proliferation, differentiation, and bioactivity in the stimulated body fluid (SBF), were enhanced by the presence of BG-CH composite coatings, which also suggested that this composite coating method could provide an effective solution for the weak PEEK-bone integration.

Deep-water northern Gulf of Mexico hydrocarbon plays

International Nuclear Information System (INIS)

Peterson, R.H.; Cooke, D.W.

1995-01-01

The geologic setting in the deep-water (depths greater than 1,500 feet) Gulf of Mexico is very favorable for the existence of large, commercial hydrocarbon accumulations. These areas have active salt tectonics that create abundant traps, underlying mature Mesozoic source rocks that can be observed expelling oil and gas to the ocean surface, and good quality reservoirs provided by turbidite sand deposits. Despite the limited amount of drilling in the deep-water Gulf of Mexico, 11 deep-water accumulations have been discovered which, when developed, will rank in the top 100 largest fields in the Gulf of Mexico. Proved field discoveries (those with announced development plans) have added over 1 billion barrels of oil equivalent to Gulf of Mexico reserves, and unproved field discoveries may add to additional billion barrels of oil equivalent. The Minerals Management Service, United States Department of the Interior, has completed a gulf-wide review of over 1,086 oil and gas fields and placed every pay sand in each field into a hydrocarbon play (plays are defined by chronostratigraphy, lithostratigraph, structure, and production). Seven productive hydrocarbon plays were identified in the deep-water northern Gulf of Mexico. Regional maps illustrate the productive limits of each play. In addition, field data, dry holes, and wells with sub-economic pay were added to define the facies and structural limits for each play. Areas for exploration potential are identified for each hydrocarbon play. A type field for each play is chosen to demonstrate the play's characteristics

Playful Literacy

DEFF Research Database (Denmark)

Froes, Isabel

these practices, which compose the taxonomy of tablet play. My contribution lies in identifying and proposing a series of theoretical concepts that complement recent theories related to play and digital literacy studies. The data collected through observations informed some noteworthy aspects, including how...... with tablets’ physical and digital affordances shape children’s digital play. This thesis presents how young children’s current practices when playing with tablets inform digital experiences in Denmark and Japan. Through an interdisciplinary lens and a grounded theory approach, I have identified and mapped...... vocabulary in children’s digital play experiences. These early digital experiences set the rules for the playgrounds and assert digital tablets as twenty-first-century toys, shaping young children’s playful literacy....

Modeling ADHD-type arousal with unilateral frontal cortex damage in rats and beneficial effects of play therapy.

Science.gov (United States)

Panksepp, Jaak; Burgdorf, Jeff; Turner, Cortney; Gordon, Nakia

2003-06-01

It has been recently shown that human adolescents with Attention Deficit/Hyperactivity Disorder (ADHD) have frontal lobe deficits, especially on the right sides of their brains (). ADHD is commonly treated with psychostimulants which may have adverse consequences. Hence, less invasive therapies need to be developed. In the present work, we tested the ability of right frontal lesions to induce hyperactivity in rats. We also evaluated the effects of chronic play therapy during early adolescence to reduce both hyperactivity and the elevated playfulness later in development. Play therapy was able to reduce both hyperactivity and excessive playfulness. In additional work, we found that access to rough-and-tumble play in normal animals could enhance subsequent behavioral indices of behavioral inhibition (i.e., freezing in response to a startle stimulus) that appeared to be independent of increased fearfulness and fatigue. Overall, these results suggest that (1) neonatal frontal lobe lesions can be used as an animal model of the overactivity in ADHD and (2) rough-and-tumble play therapy may be a new useful treatment for ADHD.

Play Therapy

Science.gov (United States)

Lawver, Timothy; Blankenship, Kelly

2008-01-01

Play therapy is a treatment modality in which the therapist engages in play with the child. Its use has been documented in a variety of settings and with a variety of diagnoses. Treating within the context of play brings the therapist and the therapy to the level of the child. By way of an introduction to this approach, a case is presented of a six-year-old boy with oppositional defiant disorder. The presentation focuses on the events and interactions of a typical session with an established patient. The primary issues of the session are aggression, self worth, and self efficacy. These themes manifest themselves through the content of the child’s play and narration of his actions. The therapist then reflects these back to the child while gently encouraging the child toward more positive play. Though the example is one of nondirective play therapy, a wide range of variation exists under the heading of play therapy. PMID:19724720

Effect of proteins on the surface microstructure evolution of a CoCrMo alloy in bio-tribocorrosion processes.

Science.gov (United States)

Wang, Zhongwei; Yan, Yu; Su, Yanjing; Qiao, Lijie

2016-09-01

Under tribological contact, the subsurface microstructure of CoCrMo alloys for artificial joint implants can be changed and affect the life and safety of such devices. As one of the most important and abundant components in the synovial fluid, proteins play a key role in affecting the bio-tribocorrosion behaviors of metal implants. The effect of proteins on the subsurface microstructure evolution of a CoCrMo alloy was investigated using a transmission electron microscope (TEM) in this study. The result shows that proteins have two main effects on the subsurface's evolution: forming a multilayered structure and causing severer subsurface deformation. The tribo-film can protect the passive film from scrapping, and then the passive film can reduce or even suppress the stacking fault annihilation by blocking the access to the metal surface. It leads to the stacking fault being diffused towards the deeper area and a strain accumulation in the subsurface, before inducing a severer deformation. On the other hand, the effect of proteins results in the location changing from the top surface to be underneath the top surface, where the maximum frictional shear stress occurs. This can cause a deeper deformation. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of Play-based Occupational Therapy on Symptoms of Hospitalized Children with Cancer: A Single-subject Study.

Science.gov (United States)

Mohammadi, Ahmad; Mehraban, Afsoon Hassani; Damavandi, Shahla A

2017-01-01

Cancer is one of the four leading causes of death in children. Its courses of diagnosis and treatment can cause physiologic symptoms and psychological distress that secondarily affect children's quality of life and participation in daily activities. The aim of this study was to investigate the effect of play-based occupational therapy on pain, anxiety, and fatigue in hospitalized children with cancer who were receiving chemotherapy. Two hospitalized children with acute lymphoblastic leukemia at least 4 months after diagnoses who received two courses of chemotherapy participated in this pilot study. Takata Play History and Iranian Children Participation Assessment Scale were used to develop intervention protocol. Nine, 30-45 min play-based occupational therapy sessions took place for each child. Children filled out the Faces Pain Scale, Visual Fatigue Scale, and Faces Anxiety Scale before and after each intervention session. Pain, anxiety, and fatigue levels decreased in both participants. Furthermore, the results showed a relationship between pain, anxiety, and fatigue variables in these children. Play-based occupational therapy can be effective in improving pain, anxiety, and fatigue levels in hospitalized children with cancer receiving chemotherapy.

Effect of play-based occupational therapy on symptoms of hospitalized children with cancer: A single-subject study

Directory of Open Access Journals (Sweden)

Ahmad Mohammadi

2017-01-01

Full Text Available Objective: Cancer is one of the four leading causes of death in children. Its courses of diagnosis and treatment can cause physiologic symptoms and psychological distress that secondarily affect children's quality of life and participation in daily activities. The aim of this study was to investigate the effect of play-based occupational therapy on pain, anxiety, and fatigue in hospitalized children with cancer who were receiving chemotherapy. Methods: Two hospitalized children with acute lymphoblastic leukemia at least 4 months after diagnoses who received two courses of chemotherapy participated in this pilot study. Takata Play History and Iranian Children Participation Assessment Scale were used to develop intervention protocol. Nine, 30–45 min play-based occupational therapy sessions took place for each child. Children filled out the Faces Pain Scale, Visual Fatigue Scale, and Faces Anxiety Scale before and after each intervention session. Results: Pain, anxiety, and fatigue levels decreased in both participants. Furthermore, the results showed a relationship between pain, anxiety, and fatigue variables in these children. Conclusions: Play-based occupational therapy can be effective in improving pain, anxiety, and fatigue levels in hospitalized children with cancer receiving chemotherapy.

The effect of a program to promote play to reduce children's post-surgical pain: with plush toys, it hurts less.

Science.gov (United States)

Ullán, Ana M; Belver, Manuel H; Fernández, Esperanza; Lorente, Felix; Badía, Marta; Fernández, Beatriz

2014-03-01

Various nonpharmacological strategies to relieve hospitalized children's pain propose play as a central element. Play is considered an essential resource to improve the negative psychosocial effects of the disease and the hospitalization itself. However, the empirical research of play in health settings has not received much attention. The goal of this study was to determine the effect of a program to promote play in the hospital on postsurgical pain in pediatric patients. The research hypothesis was that children will manifest less pain if they are distracted through play during the postsurgical period. We carried out a randomized parallel trial with two groups, an experimental group and a control group. The control group did not receive any specific treatment, only the standard attention contemplated in the hospital. The parents of the children from the experimental group received instructions to play with their children in the postsurgical period and specific play material with which to play. The results obtained support the research hypothesis. On average, the children from the experimental group scored lower on a pain scale than the children from the control group. This occurred in the three postsurgical measurements of pain. It is concluded that the program to promote play can decrease children's perception of pain. Copyright © 2014 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Non-Digital Game Playing by Older Adults.

Science.gov (United States)

Mortenson, W Ben; Sixsmith, Andrew; Kaufman, David

2017-09-01

Research on video games' effect on cognition and behaviour has been extensive, yet little research has explored non-digital forms of game playing, especially among older adults. As part of a larger survey on game playing, 886 respondents (≥ age 55) filled out questionnaires about non-digital game play. The study aims were to determine perceived benefits of non-digital game play and to determine socio-demographic factors that might predict perceived benefits. Survey results indicate that non-digital game playing is social in nature and common (73% of respondents) among older adults. Older adults play for fun, but also to help maintain their cognition. Regression analyses indicated various socio-demographic factors - age, education, gender, and race - were independently associated with perceived benefits from game playing. The results thus emphasize the importance of non-digital game playing in this population and suggest that efforts to facilitate game playing may improve social interactions and quality of life.

The Effect of Entonox, Play Therapy and a Combination on Pain Relief in Children: A Randomized Controlled Trial.

Science.gov (United States)

Mohan, Simi; Nayak, Ruma; Thomas, Reju Joseph; Ravindran, Vinitha

2015-12-01

Pediatric pain is often undertreated/neglected due to time constraints, difficulties in timing of oral analgesics, fear of side effects of opioids and anxiolytics, and apprehension of additional pain in the use of local anesthetic injections. In this study, the researcher was prompted to choose rapidly acting interventions that were low dose and allowed the child to stay alert, suitable for a quick discharge. The purpose of this study was to evaluate the effects of Entonox, play therapy, and a combination to relieve procedural pain in children aged 4-15 years. The study was designed as a randomized controlled trial; the subjects were divided into four groups using a sequential allocation plan from 123 total subjects. Group A received Entonox, Group B received play therapy, Group C received both Entonox and play therapy, and Group D received existing standard interventions. The study was vetted by the departmental study review committee. The pain level was assessed using FLACC scale for children aged 4-9 years and the Wong Bakers Faces Pain Scale for children aged 10-15 years; scores ranged from 0 to 10. All the data were analyzed using SPSS 16.0 with descriptive statistics and, inferential statistics. The mean pain scores were as follows: Entonox group, 2.87; Play therapy group, 4; combination group, 3; and control group, 5.87. When statistical testing was applied, a significant reduction in the pain score in all the three experimental groups when compared to the control group was found (p = .002), but not in the pain score among the three experimental groups (p = .350). The findings of this study indicated that all three interventions were effective in lowering pain scores when compared to the control group. Play therapy is as potent as Entonox in relieving procedural pain, though there was no additive effect on pain relief when play therapy and Entonox were combined. A protocol for age-related choice between play therapy and Entonox administration was introduced

Impact of Changes in Playing Time on Playing-Related Musculoskeletal Pain in String Music Students.

Science.gov (United States)

Robitaille, Judith; Tousignant-Laflamme, Yannick; Guay, Manon

2018-03-01

During their training, musicians must develop good work habits that they will carry on throughout their professional career in order to avoid potential chronic health problems, such as musculoskeletal pain. The effect of sudden changes in instrument playing-time on the development of playing-related musculoskeletal pain (PRMP) has not been thoroughly investigated in music students playing bowed string instruments (BSI), even though they are regularly exposed to such changes to perfect their playing skills. To explore the association between sudden changes in instrument playing-time and changes in PRMP in BSI players. A prospective cohort study was completed with BSI students attending a summer music camp offering high-level training. Participants completed a self-administered 23-item questionnaire designed for the study upon arrival at camp (T1) and then 7 days later (T2). Ninety-three BSI students (16±4 yrs old) completed the questionnaires, for a 23% response rate. Their playing-time increased by 23±14 hrs between T1 and T2. Complaints in pain frequency (e.g., from never to most of the time) and intensity (19±24 mm on VAS) significantly increased between T1 and T2 and were correlated with an increase in playing-time. A sudden increase in playing-time, such as that experienced by elite BSI students attending an intensive music camp, was related to an increase in PRMP. However, in this study, changes in pain characteristics were only partly explained by the change in playing-time.

Effects of hydrogen peroxide bleaching strips on tooth surface color, surface microhardness, surface and subsurface ultrastructure, and microchemical (Raman spectroscopic) composition.

Science.gov (United States)

Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

2006-01-01

This study examined the effects of hydrogen peroxide tooth bleaching strips on the surface hardness and morphology of enamel and the ultrastructure and chemical composition of enamel and dentin in vitro. Sound human molars were ground and polished to prepare a uniform substrate for bleaching treatments. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching strips, which utilize hydrogen peroxide in a gel as the in situ bleaching source at 6.0 and 6.5% concentrations of H2O2. Control treatments included an untreated group. Crest Whitestrips bleaching included treatment exposures simulating 2x the recommended clinical exposures (28 hours bleaching). Surface color measurements were taken prior to and following bleaching to ensure tooth bleaching activity. The effects of bleach on physical properties of enamel were assessed with microhardness measures. Ultrastructural effects were classified by surface and subsurface confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) techniques. In addition, the effects of bleaching on tooth microchemical composition was studied in different tooth regions by coincident assessment of Raman spectroscopic signature. Color assessments confirmed significant ex vivo tooth bleaching by Whitestrips. Surface microhardness and SEM measures revealed no deleterious effects on the enamel surfaces. CLSM micromorphological assessments supported the safety of hydrogen peroxide bleaching strips both on surface and subsurface enamel, DEJ, and dentin ultrastructure. Raman spectroscopy analysis demonstrated no obvious effects of bleaching treatments on the microchemical composition of enamel and dentin. These results confirm that tooth bleaching with hydrogen peroxide whitening strips does not produce changes in surface

Design for Play

DEFF Research Database (Denmark)

Feder, Karen

2017-01-01

Abstract The purpose of the new Design for Play initiative is to inspire and educate designers to design for the future of play. To create “play ambassadors” equipped with excellent tools, methods, approaches and mind-sets to design for the playful human being in an ever-changing world. To teach...... and inspire children to grow up to be creative designers of their own life and the world around them. The Design for Play research team will study the interplay between people, processes and products in design for play and support the development of playful designers, playful solutions and playful experiences...

Surface zwitterionization: Effective method for preventing oral bacterial biofilm formation on hydroxyapatite surfaces

Science.gov (United States)

Lee, Myoungjin; Kim, Heejin; Seo, Jiae; Kang, Minji; Kang, Sunah; Jang, Joomyung; Lee, Yan; Seo, Ji-Hun

2018-01-01

In this study, we conducted surface zwitterionization of hydroxyapatite (HA) surfaces by immersing them in the zwitterionic polymer solutions to provide anti-bacterial properties to the HA surface. Three different monomers containing various zwitterionic groups, i.e., phosphorylcholine (PC), sulfobetaine (SB), and carboxybetaine (CB), were copolymerized with the methacrylic monomer containing a Ca2+-binding moiety, using the free radical polymerization method. As a control, functionalization of the copolymer containing the Ca2+-binding moiety was synthesized using a hydroxy group. The stable immobilization of the zwitterionic functional groups was confirmed by water contact angle analysis and X-ray photoelectron spectroscopy (XPS) measurement conducted after the sonication process. The zwitterionized HA surface showed significantly decreased protein adsorption, whereas the hydroxyl group-coated HA surface showed limited efficacy. The anti-bacterial adhesion property was confirmed by conducting Streptococcus mutans (S. mutans) adhesion tests for 6 h and 24 h. When furanone C-30, a representative anti-quorum sensing molecule for S. mutans, was used, only a small amount of bacteria adhered after 6 h and the population did not increase after 24 h. In contrast, zwitterionized HA surfaces showed almost no bacterial adhesion after 6 h and the effect was retained for 24 h, resulting in the lowest level of oral bacterial adhesion. These results confirm that surface zwitterionization is a promising method to effectively prevent oral bacterial adhesion on HA-based materials.

Teaching Peace: Alternatives to Violent Play.

Science.gov (United States)

Jurek, Dianne Miller; Velazquez, Michaela

1995-01-01

To help combat the effects of violence on children and improve the quality and nature of play, early childhood teachers can: define violence by helping children become aware of the issue, help children resolve their own conflicts, create a peace place in the classroom, intervene when violent play occurs, evaluate media and toys, and educate…

Effects of Surface Treatment of Activated Carbon on Its Surface and Cr(VI) Adsorption Characteristics

Energy Technology Data Exchange (ETDEWEB)

Park, Soo Jin; Jang, Yu Sin [Advanced Materials Division., Korea Research Institute of Chimical Technology, Taejon (Korea)

2001-04-01

In this work, the effect of surface treatments on activated carbons (ACs) has been studied in the context of gas and liquid adsorption behaviors. The chemical solutions used in this experiment were 35% sodium hydroxide, and these were used for the acidic and basic treatments, respectively. The surface properties have been determined by pH, acid-base values, and FT-IR. The adsorption isotherms of Cr(VI) ion on activated carbons have been studied with the 5 mg/l concentration at ambient temperature. N{sub 2} adsorption isotherm characteristics, which include the specific surface area, micro pore volume, and microporosity, were determined by BET and Boer's-plot methods. In case of the acidic treatment of activated carbons, it was observed that the adsorption of Cr(VI) ion was more effective due to the increase acid value (or acidic functional group) of activated carbon surfaces. However, the basic treatment on activated carbons was caused no significant effects, probably due to the decreased specific surface area and total pore volume. 27 refs., 7 figs., 4 tabs.

FairyPlay

DEFF Research Database (Denmark)

Toft, Herdis

2018-01-01

in a play culture where children recycle them in transmitted, transformed and transgressive modes. His fairy tales function as raw materials – trash – for play-production, and these contemporary children muddle, mingle, remix their formulas and elements with other materials and adjust them to a play context......Hans Christian Andersen is a cultural icon in the Danish community, and his fairy tales are canonized as treasured Danish cultural heritage. However, situated as they are today in a crosscultural mix between folklore, booklore and medialore, they also may be analysed as useful, treasured trash...... through improvisations. So they perform what we shall name FairyPlay - just like Hans Christian Andersen himself did. We show Hans Christian Andersen as an intimate connoisseur of play culture, a homo ludens, a trash-sculptor and a thing-finder, like Pippi Longstocking and like children in play. Examples...

Bonding of radioactive contamination. IV. Effect of surface finish

International Nuclear Information System (INIS)

Rankin, W.N.

1983-01-01

The mechanisms by which radioactive contamination would be bonded to a DWPF canister are being investigated. Previous investigations in this series have examined the effects of temperature, oxidation before contamination, and atmosphere composition control on the bonding of contamination. This memorandum describes the results of tests to determine the effect of special surface finishes on the bonding of contamination to waste glass canisters. Surface pretreatments which produce smoother canister surfaces actually cause radioactive contamination to be more tightly bonded to the metal surface than on an untreated surface. Based on the results of these tests it is recommended that the canister surface finish be specified as having a bright cold rolled mill finish equivalent to ASTM No. 2B. 7 references, 3 figures, 3 tables

Effects of Ce concentrations on ignition temperature and surface tension of Mg-9wt.%Al alloy

OpenAIRE

Deng Zhenghua; Li Huaji; Zhao Wanjun

2013-01-01

Magnesium alloys are well known for their excellent properties, but the potential issues with oxidation and burning during melting and casting largely limit its industrial applications. The addition of Ce in magnesium alloys can significantly raise ignition-proof performance and change the structure of the oxide film on the surface of the molten metal as well as the surface tension values. Surface tension is an important physical parameter of the metal melts, and it plays an important role in...

Playing violent video games increases intergroup bias.

Science.gov (United States)

Greitemeyer, Tobias

2014-01-01

Previous research has shown how, why, and for whom violent video game play is related to aggression and aggression-related variables. In contrast, less is known about whether some individuals are more likely than others to be the target of increased aggression after violent video game play. The present research examined the idea that the effects of violent video game play are stronger when the target is a member of an outgroup rather than an ingroup. In fact, a correlational study revealed that violent video game exposure was positively related to ethnocentrism. This relation remained significant when controlling for trait aggression. Providing causal evidence, an experimental study showed that playing a violent video game increased aggressive behavior, and that this effect was more pronounced when the target was an outgroup rather than an ingroup member. Possible mediating mechanisms are discussed.

Sexually dimorphic effects of a prenatal immune challenge on social play and vasopressin expression in juvenile rats

Directory of Open Access Journals (Sweden)

Taylor Patrick V

2012-06-01

Full Text Available Abstract Background Infectious diseases and inflammation during pregnancy increase the offspring’s risk for behavioral disorders. However, how immune stress affects neural circuitry during development is not well known. We tested whether a prenatal immune challenge interferes with the development of social play and with neural circuits implicated in social behavior. Methods Pregnant rats were given intraperitoneal injections of the bacterial endotoxin lipopolysaccharide (LPS – 100 μg /kg or saline on the 15th day of pregnancy. Offspring were tested for social play behaviors between postnatal days 26–40. Brains were harvested on postnatal day 45 and processed for arginine vasopressin (AVP mRNA in situ hybridization. Results In males, LPS treatment reduced the frequency of juvenile play behavior and reduced AVP mRNA expression in the medial amygdala and bed nucleus of the stria terminalis. These effects were not found in females. LPS treatment did not change AVP mRNA expression in the suprachiasmatic nucleus, paraventricular nucleus, or supraoptic nucleus of either sex, nor did it affect the sex difference in the size of the sexually dimorphic nucleus of the preoptic area. Conclusions Given AVP’s central role in regulating social behavior, the sexually dimorphic effects of prenatal LPS treatment on male AVP mRNA expression may contribute to the sexually dimorphic effect of LPS on male social play and may, therefore, increase understanding of factors that contribute to sex differences in social psychopathology.

Numerical Investigation of Effect of Surface Roughness in a Microchannel

Energy Technology Data Exchange (ETDEWEB)

Shin, Myung Seob; Byun, Sung Jun; Yoon, Joon Yong [Hanyang University, Seoul (Korea, Republic of)

2010-05-15

In this paper, lattice Boltzmann method(LBM) results for a laminar flow in a microchannel with rough surface are presented. The surface roughness is modeled as an array of rectangular modules placed on the top and bottom surface of a parallel-plate channel. The effects of relative surface roughness, roughness distribution, and roughness size are presented in terms of the Poiseuille number. The roughness distribution characterized by the ratio of the roughness height to the spacing between the modules has a negligible effect on the flow and friction factors. Finally, a significant increase in the Poiseuille number is observed when the surface roughness is considered, and the effects of roughness on the microflow field mainly depend on the surface roughness.

Combined Effects of Surface Morphology and Mechanical Straining Magnitudes on the Differentiation of Mesenchymal Stem Cells without Using Biochemical Reagents

Directory of Open Access Journals (Sweden)

Ji-Yeon Jang

2011-01-01

Full Text Available Existing studies examining the control of mesenchymal stem cell (MSC differentiation into desired cell types have used a variety of biochemical reagents such as growth factors despite possible side effects. Recently, the roles of biomimetic microphysical environments have drawn much attention in this field. We studied MSC differentiation and changes in gene expression in relation to osteoblast-like cell and smooth muscle-like cell type resulting from various microphysical environments, including differing magnitudes of tensile strain and substrate geometries for 8 days. In addition, we also investigated the residual effects of those selected microphysical environment factors on the differentiation by ceasing those factors for 3 days. The results of this study showed the effects of the strain magnitudes and surface geometries. However, the genes which are related to the same cell type showed different responses depending on the changes in strain magnitude and surface geometry. Also, different responses were observed three days after the straining was stopped. These data confirm that controlling microenvironments so that they mimic those in vivo contributes to the differentiation of MSCs into specific cell types. And duration of straining engagement was also found to play important roles along with surface geometry.

Play Therapy: Facilitative Use of Child's Play in Elementary School Counseling.

Science.gov (United States)

Landreth, Garry L.

1987-01-01

Reviews five major developments in play therapy: psychoanalysis, release therapy, relationship therapy, nondirective therapy, and play therapy in school settings. Suggests ways school counselors can use play therapy. Describes play therapy facilities, location selection, and play materials. Lists objectives of play therapy and how teachers can aid…

Effects of surface relaxation and reconstruction on the vibration characteristics of nanobeams

International Nuclear Information System (INIS)

Zhang, Wen-Ming; Hu, Kai-Ming; Peng, Zhi-Ke; Meng, Guang; Yang, Bin

2016-01-01

Surface effects on the free vibration characteristics of nanobeams are investigated by a modified continuum model. In this paper, the relationship between the parameters of the modified continuum model of surface effects including surface elasticity, surface density, and residual surface stresses, and the parameters of the atomistic lattice model such as surface relaxation and reconstruction in nanobeams is characterized by an atomistic lattice model. The surface effects are incorporated into nanobeams to develop a modified continuum model depicting the free vibrational behavior of nanobeams. The model is validated with the experimental data of an effective size-dependent Young’s modulus and the previous theoretical results. The results demonstrate that both surface elasticity and surface density vary exponentially with surface layer thickness. Therefore, surface elasticity and density can be affected by surface relaxation and residual surface stresses can be induced by surface reconstruction. The natural frequencies of doubly clamped nanobeams can be affected by the dimensions of the nanobeams, surface layer thickness, and residual surface stress. This work may be helpful for understanding surface effects and their influence on the vibrational behavior of nanobeams. (paper)

Mediatized play

DEFF Research Database (Denmark)

Johansen, Stine Liv

Children’s play must nowadays be understood as a mediatized field in society and culture. Media – understood in a very broad sense - holds severe explanatory power in describing and understanding the practice of play, since play happens both with, through and inspired by media of different sorts........ In this presentation the case of ‘playing soccer’ will be outlined through its different mediated manifestations, including soccer games and programs on TV, computer games, magazines, books, YouTube videos and soccer trading cards....

Tribological effects of polymer surface modification through plastic

Indian Academy of Sciences (India)

Tribological effects of polymer surface modification through plastic deformation. K O Low K J Wong ... In this regard, a surface modification technique through plastic deformation has been implemented. ... Bulletin of Materials Science | News.

Surface-environment effects in spin crossover solids

Energy Technology Data Exchange (ETDEWEB)

Gudyma, Iu., E-mail: yugudyma@gmail.com; Maksymov, A.

2017-06-15

Highlights: • The spin-crossover nanocrystals were described by modified Ising-like model. • The ligand field on the surface is a function of external fluctuations. • The thermal hysteresis with surface and bulk interactions of the lattice was studied. • The system behavior with fluctuating ligand field on the surface was examined. • The fluctuations enlarge the hysteresis, but smaller surface interaction narrows it. - Abstract: The impact of surface effects on thermal induced spin crossover phenomenon is a subject of a broad and current interest. Using the modified Ising-like model of spin crossover solids with the ligand field as function of the molecule’ positions and random component on surface by means of Metropolis Monte Carlo algorithm the thermal spin transition curves were calculated. The analysis of spin configuration during transition gives a general idea about contribution of molecules from the surface and inside the lattice into resulting magnetization of the systems. The behavior of hysteresis loop for various surface coupling and fluctuations strength has been described.

Effects of playing a violent video game as male versus female avatar on subsequent aggression in male and female players.

Science.gov (United States)

Yang, Grace S; Huesmann, L Rowell; Bushman, Brad J

2014-01-01

Previous research has shown that violent video games can increase aggression in players immediately after they play. The present research examines the effects of one subtle cue within violent video games that might moderate these effects-whether the avatar is male or female. One common stereotype is that males are more aggressive than females. Thus, playing a violent video game as a male avatar, compared to a female avatar, should be more likely to prime aggressive thoughts and inclinations in players and lead to more aggressive behavior afterwards. Male and female university students (N = 242) were randomly assigned to play a violent video game as a male or female avatar. After gameplay, participants gave an ostensible partner who hated spicy food hot sauce to eat. The amount of hot sauce given was used to measure aggression. Consistent with priming theory, results showed that both male and female participants who played a violent game as a male avatar behaved more aggressively afterwards than those who played as female avatar. The priming effects of the male avatar were somewhat stronger for male participants than for female participants, suggesting that male participants identified more with the male avatar than did the female participants. These results are particularly noteworthy because they are consistent with another recent experiment showing that playing a violent game as an avatar with a different stereotypically aggressive attribute (black skin color) stimulates more aggression than playing as an avatar without the stereotypically aggressive attribute (Yang et al., 2014, Social Psychological and Personality Science). © 2014 Wiley Periodicals, Inc.

Nonlinear free vibration of piezoelectric nanobeams incorporating surface effects

International Nuclear Information System (INIS)

Hosseini-Hashemi, Shahrokh; Nahas, Iman; Fakher, Mahmood; Nazemnezhad, Reza

2014-01-01

In this study, the nonlinear free vibration of piezoelectric nanobeams incorporating surface effects (surface elasticity, surface tension, and surface density) is studied. The governing equation of the piezoelectric nanobeam is derived within the framework of Euler–Bernoulli beam theory with the von Kármán geometric nonlinearity. In order to satisfy the balance conditions between the nanobeam bulk and its surfaces, the component of the bulk stress, σ zz , is assumed to vary linearly through the nanobeam thickness. An exact solution is obtained for the natural frequencies of a simply supported piezoelectric nanobeam in terms of the Jacobi elliptic functions using the free vibration mode shape of the corresponding linear problem. Then, the influences of the surface effects and the piezoelectric field on the nonlinear free vibration of nanobeams made of aluminum and silicon with positive and negative surface elasticity, respectively, have been studied for various properties of the piezoelectric field, various nanobeam sizes and amplitude ratios. It is observed that if the Young’s modulus of a nanobeam is lower, the effect of the piezoelectric field on the frequency ratios (FRs) of the nanobeam will be greater. In addition, it is seen that by increasing the nanobeam length so that the nanobeam cross section is set to be constant, the surface effects and the piezoelectric field with negative voltage values increases the FRs, whereas it is the other way around when the nanobeam cross section is assumed to be dependent on the length of the nanobeam. (paper)

Effects of surface tension on tray point efficiencies

Energy Technology Data Exchange (ETDEWEB)

Chen, G.X.; Afacan, A.; Chuang, K.T. (Alberta Univ., Edmonton, AB (Canada))

1994-08-01

Sieve tray efficiencies for the distillation of methanol/water, acetic acid/water, and cyclohexane/n-heptane mixtures were measured as a function of composition under fixed vapor and liquid rates in a 0.15 m diameter distillation column. The three binary distillation systems used in the study had a wide range of surface tensions measured as a function of composition. From the efficiencies measured, the number of vapor- and liquid-phase transfer units (Ng and Nl) was determined and the effects of surface tension on Ng and Nl were identified. To further verify the results obtained from the distillation column, bubble sizes in froths for air/water, air/methanol, and air/(water + surfactant) systems with different surface tensions were measured. The results show that surface tension has a significant effect on tray efficiency and the number of transfer units. Bubble sizes in the tray froths were mainly determined by surface tension, and bubble breakup and coalescence occur in the froths. 45 refs., 15 figs., 1 tab.

Biomimicking micropatterned surfaces and their effect on marine biofouling.

Science.gov (United States)

Brzozowska, Agata M; Parra-Velandia, Fernando J; Quintana, Robert; Xiaoying, Zhu; Lee, Serina S C; Chin-Sing, Lim; Jańczewski, Dominik; Teo, Serena L-M; Vancso, Julius G

2014-08-05

When synthetic materials are submerged in marine environments, dissolved matter and marine organisms attach to their surfaces by a process known as marine fouling. This phenomenon may lead to diminished material performance with detrimental consequences. Bioinspired surface patterning and chemical surface modifications present promising approaches to the design of novel functional surfaces that can prevent biofouling phenomena. In this study, we report the synergistic effects of surface patterns, inspired by the marine decapod crab Myomenippe hardwickii in combination with chemical surface modifications toward suppressing marine fouling. M. hardwickii is known to maintain a relatively clean carapace although the species occurs in biofouling communities of tropical shallow subtidal coastal waters. Following the surface analysis of selected specimens, we designed hierarchical surface microtopographies that replicate the critical features observed on the crustacean surface. The micropatterned surfaces were modified with zwitterionic polymer brushes or with layer-by-layer deposited polyelectrolyte multilayers to enhance their antifouling and/or fouling-release potential. Chemically modified and unmodified micropatterned surfaces were subjected to extensive fouling tests, including laboratory assays against barnacle settlement and algae adhesion, and field static immersion tests. The results show a statistically significant reduction in settlement on the micropatterned surfaces as well as a synergistic effect when the microtopographies are combined with grafted polymer chains.

Effect of strain on surface diffusion and nucleation

DEFF Research Database (Denmark)

Brune, Harald; Bromann, Karsten; Röder, Holger

1995-01-01

The influence of strain on diffusion and nucleation has been studied by means of scanning tunneling microscopy and effective-medium theory for Ag self-diffusion on strained and unstrained (111) surfaces. Experimentally, the diffusion barrier is observed to be substantially lower on a pseudomorphic...... effect on surface diffusion and nucleation in heteroepitaxy and are thus of significance for the film morphology in the kinetic growth regime....

Strong coupling electrostatics for randomly charged surfaces: antifragility and effective interactions.

Science.gov (United States)

Ghodrat, Malihe; Naji, Ali; Komaie-Moghaddam, Haniyeh; Podgornik, Rudolf

2015-05-07

We study the effective interaction mediated by strongly coupled Coulomb fluids between dielectric surfaces carrying quenched, random monopolar charges with equal mean and variance, both when the Coulomb fluid consists only of mobile multivalent counterions and when it consists of an asymmetric ionic mixture containing multivalent and monovalent (salt) ions in equilibrium with an aqueous bulk reservoir. We analyze the consequences that follow from the interplay between surface charge disorder, dielectric and salt image effects, and the strong electrostatic coupling that results from multivalent counterions on the distribution of these ions and the effective interaction pressure they mediate between the surfaces. In a dielectrically homogeneous system, we show that the multivalent counterions are attracted towards the surfaces with a singular, disorder-induced potential that diverges logarithmically on approach to the surfaces, creating a singular but integrable counterion density profile that exhibits an algebraic divergence at the surfaces with an exponent that depends on the surface charge (disorder) variance. This effect drives the system towards a state of lower thermal 'disorder', one that can be described by a renormalized temperature, exhibiting thus a remarkable antifragility. In the presence of an interfacial dielectric discontinuity, the singular behavior of counterion density at the surfaces is removed but multivalent counterions are still accumulated much more strongly close to randomly charged surfaces as compared with uniformly charged ones. The interaction pressure acting on the surfaces displays in general a highly non-monotonic behavior as a function of the inter-surface separation with a prominent regime of attraction at small to intermediate separations. This attraction is caused directly by the combined effects from charge disorder and strong coupling electrostatics of multivalent counterions, which dominate the surface-surface repulsion due to

Study the Postbuckling of Hexagonal Piezoelectric Nanowires with Surface Effect

Directory of Open Access Journals (Sweden)

O. Rahmani

2014-04-01

Full Text Available Piezoelectric nanobeams having circular, rectangular and hexagonal cross-sections are synthesized and used in various Nano structures; however, piezoelectric nanobeams with hexagonal cross-sections have not been studied in detail. In particular, the physical mechanisms of the surface effect and the role of surface stress, surface elasticity and surface piezoelectricity have not been discussed thoroughly. The present study investigated post-buckling behavior of piezoelectric nanobeams by examining surface effects. The energy method was applied to post-buckling of hexagonal nanobeams and the critical buckling voltage and amplitude are derived analytically from bulk and surface material properties and geometric factors.

Play at Work

DEFF Research Database (Denmark)

Meier Sørensen, Bent; Spoelstra, Sverre

2012-01-01

The interest in organizational play is growing, both in popular business discourse and organization studies. As the presumption that play is dysfunctional for organizations is increasingly discarded, the existing positions may be divided into two camps; one proposes ‘serious play’ as an engine fo...... workplaces engage in play: play as a (serious) continuation of work, play as a (critical) intervention into work and play as an (uninvited) usurpation of work....

Effects of a Play-Based Teacher Consultation (PBTC) Program on Interpersonal Skills of Elementary School Teachers in the Classroom

Science.gov (United States)

Carlson, Sarah E.

2011-01-01

The purpose of this study was to examine the effectiveness of a play-based teacher consultation (PBTC) program on individual teachers' interpersonal classroom behaviors and teacher-child relationships. The research questions addressed the application of child-centered play therapy principles and PBTC increasing teacher responsiveness, decreasing…

Playful Interaction

DEFF Research Database (Denmark)

2003-01-01

The video Playful Interaction describes a future architectural office, and envisions ideas and concepts for playful interactions between people, materials and appliances in a pervasive and augmented working environment. The video both describes existing developments, technologies and designs...... as well as ideas not yet implemented such as playful modes of interaction with an augmented ball. Playful Interaction has been used as a hybrid of a vision video and a video prototype (1). Externally the video has been used to visualising our new ideas, and internally the video has also worked to inspire...

The role of play themes in non-directive play therapy.

Science.gov (United States)

Ryan, Virginia; Edge, Andrew

2012-07-01

Describing the processes underlying play therapy is important for evidence based practice in child therapy. Employing play themes to describe children's play session contents is in widespread use by practitioners, but an adequate classification of these themes for non-directive play therapy practice has not yet been established. This article sets out to fill this gap by first describing how themes can be distinguished and distilled from the contents of play therapy contents. Second, a classification of main themes and sub-themes with exemplars to illustrate these concepts which is compatible with non-directive play therapy practice is set out. Finally a pilot project with experienced play therapists to test this classification in practice is suggested, along with the research questions that will need to be investigated in the shorter and longer terms.

Teaching Play Skills to Young Children with Autism

Science.gov (United States)

Jung, Sunhwa; Sainato, Diane M.

2013-01-01

Background: Play is critical for the development of young children and is an important part of their daily routine. However, children with autism often exhibit deficits in play skills and engage in stereotypic behaviour. We reviewed studies to identify effective instructional strategies for teaching play skills to young children with autism.…

Can I Say Something? The Effects of Digital Game Play on Willingness to Communicate

Science.gov (United States)

Reinders, Hayo; Wattana, Sorada

2014-01-01

This paper reports on a study into the effects of digital game play on learners' Willingness to Communicate (WTC), or individuals' "readiness to enter into discourse at a particular time with a specific person or persons, using a L2" (MacIntyre, Dörnyei, Clément, & Noels, 1998, p. 547). Thirty Thai learners of English as a foreign…

The effect of lizardite surface characteristics on pyrite flotation

International Nuclear Information System (INIS)

Feng Bo; Feng Qiming; Lu Yiping

2012-01-01

Highlights: ► Two kinds of lizardite samples have different effect on the flotation of pyrite. ► Acid leaching changed the surface characteristics of lizardite mineral. ► The leached lizardite has less magnesium on its surface. ► The electro-kinetic behavior of lizardite aqueous suspensions is mainly a function of the Mg/Si atomic ratio on mineral surface. - Abstract: The effect of lizardite surface characteristics on pyrite flotation has been investigated through flotation tests, adsorption tests, zeta potential measurements, FTIR study, X-ray photoelectron spectroscopy (XPS) and sedimentation tests. The flotation results show that at pH value 9, where flotation of nickel sulfide ores is routinely performed, two kinds of lizardite samples (native lizardite and leached lizardite) have different effects on the flotation of pyrite. The native lizardite adheres to the surface of pyrite and reduces pyrite flotation recovery while the leached lizardite does not interfere with pyrite flotation. Infrared analyses and XPS tests illustrate that acid leaching changed the surface characteristics of lizardite mineral and the leached lizardite has less magnesium on its surface. It has been determined that the electro-kinetic behavior of lizardite aqueous suspensions is mainly a function of the Mg/Si atomic ratio on lizardite surface. So, the low isoelectric point observed in the leached sample has been linked to values of this ratio lower than that of the native lizardite.

Effect of surface conditions on blast wave propagation

International Nuclear Information System (INIS)

Song, Seung Ho; Li, Yi Bao; Lee, Chang Hoon; Choi, Jung Il

2016-01-01

We performed numerical simulations of blast wave propagations on surfaces by solving axisymmetric two-dimensional Euler equations. Assuming the initial stage of fireball at the breakaway point after an explosion, we investigated the effect of surface conditions considering surface convex or concave elements and thermal conditions on blast wave propagations near the ground surface. Parametric studies were performed by varying the geometrical factors of the surface element as well as thermal layer characteristics. We found that the peak overpressure near the ground zero was increased due to the surface elements, while modulations of the blast wave propagations were limited within a region for the surface elements. Because of the thermal layer, the precursor was formed in the propagations, which led to the attenuation of the peak overpressure on the ground surface

Effects of surface roughness on deviation angle and performance losses in wet steam turbines

International Nuclear Information System (INIS)

Bagheri Esfe, H.; Kermani, M.J.; Saffar Avval, M.

2015-01-01

In this paper, effects of turbine blade roughness and steam condensation on deviation angle and performance losses of the wet stages are investigated. The steam is assumed to obey non-equilibrium thermodynamic model, in which abrupt formation of liquid droplets produces condensation shocks. An AUSM-van Leer hybrid scheme is used to solve two-phase turbulent transonic steam flow around turbine rotor tip sections. The dominant solver of the computational domain is taken to be the AUSM scheme (1993) that in regions with large gradients smoothly switches to van Leer scheme (1979). This guarantees a robust hybrid scheme throughout the domain. It is observed that as a result of condensation, the aerothermodymics of the flow field changes. For example for a supersonic wet case with exit isentropic Mach number M e,is  = 1.45, the deviation angle and total pressure loss coefficient change by 65% and 200%, respectively, when compared with dry case. It is also observed that losses due to surface roughness in subsonic regions are much larger than those in supersonic regions. Hence, as a practical guideline for maintenance sequences, cleaning of subsonic parts of steam turbines should be considered first. - Highlights: • Two-phase turbulent transonic steam flow is numerically studied in this paper. • As a result of condensation, aerothermodynamics of the flow field changes. • Surface roughness has almost negligible effect on deviation angle. • Surface roughness plays an important role in performance losses. • Contribution of different loss mechanisms for smooth and rough blades are computed.

Effective slip lengths for flows over surfaces with nanobubbles: the effects of finite slip

International Nuclear Information System (INIS)

Hendy, S C; Lund, N J

2009-01-01

We consider effective slip lengths for flows of simple liquids over surfaces contaminated by gaseous nanobubbles. In particular, we examine whether the effects of finite slip over the liquid-bubble interface are important in limiting effective slip lengths over such surfaces. Using an expression that interpolates between the perfect slip and finite slip regimes for flow over bubbles, we conclude that for the bubble dimensions and coverages typically reported in the literature the effects of finite slip are secondary, reducing effective slip lengths by only 10%. Further, we find that nanobubbles do not significantly increase slip lengths beyond those reported for bare hydrophobic surfaces.

Imagination, Playfulness, and Creativity in Children's Play with Different Toys

Science.gov (United States)

Mo????ller, Signe?? Juhl?

2015-01-01

Based on a four-month experimental study of preschool children's play with creative-construction and social-fantasy toys, the author examines the in?uence of both types of toys on the play of preschool children. Her comparative analysis considers the impact of transformative play on the development of imagination during play activities and…

Effects of XPS operational parameters on investigated sample surfaces

International Nuclear Information System (INIS)

Mrad, O.; Ismail, I.

2013-04-01

In this work, we studied the effects of the operating conditions of the xray photoelectron spectroscopy analysis technique (XPS) on the investigated samples. Firstly, the performances of the whole system have been verified as well as the accuracy of the analysis. Afterwards, the problem of the analysis of insulating samples caused by the charge buildup on the surface has been studied. The use of low-energy electron beam (<100 eV) to compensate the surface charge has been applied. The effect of X-ray on the samples have been assessed and was found to be nondestructive within the analysis time. The effect of low- and high-energy electron beams on the sample surface have been investigated. Highenergy electrons were found to have destructive effect on organic samples. The sample heating procedure has been tested and its effect on the chemical stat of the surface was followed. Finally, the ion source was used to determine the elements distribution and the chemical stat of different depths of the sample. A method has been proposed to determine these depths (author).

Surface characterization

Science.gov (United States)

Mandla A. Tshabalala

2005-01-01

Surface properties of wood play an important role when wood is used or processed into different commodities such as siding, joinery, textiles, paper, sorption media or wood composites. Thus, for example, the quality and durability of a wood coating are determined by the surface properties of the wood and the coating. The same is true for wood composites, as the...

Effects of rational surface density on resistive g turbulence

International Nuclear Information System (INIS)

Beklemishev, A.D.; Sugama, H.; Horton, W.

1993-01-01

The Beklemishev-Horton theory states that the anomalous transport coefficient is proportional to the density of rational surfaces provided that the interaction between the modes localized around different rational surfaces is weak compared with modes of the same helicity. The authors examine the effects of the density of states ρ using resistive g turbulence in 2D (single-helicity) and 3D (multi-helicity) simulations. They find that the modes with different helicities do not equipartition the available energy, but rather the coalescence or inverse cascade effect is strong so that a few low order mode rational surfaces receive most of the energy. The quasilinear flattening at the surfaces is a strong effect and they use bifurcation theory to derive that the effective diffusivity increases as χ eff = χ 0 ρ/(1 - Cρ) where C is a constant determined by interaction integrals. For a sufficiently high density of states Cρ ≤ 1, the higher order nonlinear interaction must be taken into account

The effectiveness of linguistic plays on the grammatical skills of hearing-impaired children with hearing aids

Directory of Open Access Journals (Sweden)

Sahar Mohammad Esmaeilzadeh

2014-12-01

Full Text Available Background and Aim: Grammatical skills development of hearing-impaired children depends on using appropriate educational rehabilitation programs. This study aims to investigate the effectiveness of linguistic plays on the grammatical skills in hearing-impaired children with hearing aids.Methods: Ten hearing-impaired children with hearing aids, aged between 5 and 7, were randomly assigned to two groups (5 children in each group. Each treatment group received 12 sessions on linguistic plays. The grammatical skills of these children were evaluated via the TOLD-P: 3 (Persian version; in addition, their level of intelligence was assessed by the Raven test.Results: The difference between the scores of both control and treatment groups revealed a statistically significant difference in grammatical skills (t=7.61, p=0.001 and three subskills of the children who participated in the linguistic plays. These subskills include syntactic understanding (t=3.16, p=0.013, sentence imitation (t=1.71, p=0.006, and morphological completion (t=6.55, p=0.001. In other words, the findings suggest that linguistic plays have a significant impact on the improvement of the aforementioned skills in hearing-impaired children.Conclusion: Results suggest that it would be beneficial to include linguistic plays as part of routine rehabilitation programs as a means of improving the grammatical difficulties of children. After partaking in linguistic plays, children significantly improved their ability to comprehend the meaning of sentences and also to recognize, understand, and use common Persian morphological forms.

Go Play Outside! Effects of a risk-reframing tool on mothers' tolerance for, and parenting practices associated with, children's risky play: study protocol for a randomized controlled trial.

Science.gov (United States)

Brussoni, Mariana; Ishikawa, Takuro; Han, Christina; Pike, Ian; Bundy, Anita; Faulkner, Guy; Mâsse, Louise C

2018-03-07

Children's risky play is associated with a variety of positive developmental, physical and mental health outcomes, including greater physical activity, self-confidence and risk-management skills. Children's opportunities for risky play have eroded over time, limited by parents' fears and beliefs about risk, particularly among mothers. We developed a digital tool and in-person Risk-reframing (RR) workshop to reframe parents' perceptions of risk and change parenting behaviours. The purpose of this paper is to describe our RR intervention, rationale and protocol for a randomised controlled trial to examine whether it leads to increases in mothers' tolerance of risk in play and goal attainment relating to promoting their child's opportunities for risky play. We use a randomised controlled trial design and will recruit a total of 501 mothers of children aged 6-12 years. The RR digital tool is designed for a one-time visit and includes three chapters of self-reflection and experiential learning tasks. The RR in-person tool is a 2-h facilitated workshop in which participants are guided through discussion of the same tasks contained within the digital tool. The control condition consists of reading the Position Statement on Active Outdoor Play. Primary outcome is increased tolerance of risk in play, as measured by the Tolerance of Risk in Play Scale. Secondary outcome is self-reported attainment of a behaviour-change goal that participants set for themselves. We will test the hypothesis that there will be differences between the experimental and control conditions with respect to tolerance of risk in play using mixed-effects models. We will test the hypothesis that there will be differences between the experimental and control conditions with respect to goal attainment using logistic regression. The results of this trial will have important implications for facilitating the widespread change in parents' risk perception that is necessary for promoting broad societal

Horizon effects with surface waves on moving water

Energy Technology Data Exchange (ETDEWEB)

Rousseaux, Germain; Maissa, Philippe; Mathis, Christian; Coullet, Pierre [Universite de Nice-Sophia Antipolis, Laboratoire J-A Dieudonne, UMR CNRS-UNS 6621, Parc Valrose, 06108 Nice Cedex 02 (France); Philbin, Thomas G; Leonhardt, Ulf, E-mail: Germain.Rousseaux@unice.f [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom)

2010-09-15

Surface waves on a stationary flow of water are considered in a linear model that includes the surface tension of the fluid. The resulting gravity-capillary waves experience a rich array of horizon effects when propagating against the flow. In some cases, three horizons (points where the group velocity of the wave reverses) exist for waves with a single laboratory frequency. Some of these effects are familiar in fluid mechanics under the name of wave blocking, but other aspects, in particular waves with negative co-moving frequency and the Hawking effect, were overlooked until surface waves were investigated as examples of analogue gravity (Schuetzhold R and Unruh W G 2002 Phys. Rev. D 66 044019). A comprehensive presentation of the various horizon effects for gravity-capillary waves is given, with emphasis on the deep water/ short wavelength case kh>>1, where many analytical results can be derived. A similarity of the state space of the waves to that of a thermodynamic system is pointed out.

[Effects of soil crusts on surface hydrology in the semiarid Loess hilly area].

Science.gov (United States)

Wei, Wei; Wen, Zhi; Chen, Li-Ding; Chen, Jin; Wu, Dong-Ping

2012-11-01

Soil crusts are distributed extensively in the Chinese Loess Plateau and play key roles in surface hydrological processes. In this study, a typical loess hilly region in Anjiagou catchment, Dingxi city, Gansu province was selected as the study region, and soil crusts in the catchment were investigated. Then, the hydrological effect of soil crusts was studied by using multi-sampling and hydrological monitoring experiments. Several key results were shown as follows. Firstly, compared with bared soil without crust cover, soil crusts can greatly reduce the bulk density, improve the porosity of soil, and raise the holding capacity of soil moisture which ranges from 1.4 to 1.9 times of that of bared soil. Secondly, the role of soil crust on rainfall interception was very significant. Moss crust was found to be strongest on rainfall interception, followed by synantectic crusts and lichen crusts. Bared soil without covering crusts was poorest in resisting rainfall splash. Thirdly, hydrological simulation experiments indicate that soil crusts play a certain positive role in promoting the water infiltration capacity, and the mean infiltration rate of the crusted soil was 2 times higher than that of the no-crust covered soils. While the accumulated infiltrated water amounts was also far higher than that of the bared soil.

[From fantasy to reality: understanding the way of playing of institutionalized children victims of violence through therapeutic play].

Science.gov (United States)

Giacomello, Karina Jorgino; Melo, Luciana de Lione

2011-01-01

This qualitative research is based on the reference framework of Phenomenology--analysis of the structure of the situated phenomenon, and aims to understand institutionalized children victims of violence through therapeutic play sessions. Participants were three sheltered children of preschool age, one boy and two goals. The therapeutic play sessions of the drama type were held in a reserved place and ranged from 30 to 50 minutes, using the following guiding proposal: "Let us play that we are children who live at the shelter?" Two broad theme categories could be captured: playing and pretending and playing and reality. When they are pretending while playing, sometimes calmly, sometimes violently, the children brought contents that evidenced situations in their daily family reality. When they expose their reality, the children addressed questions about the shelter institution and the bond with these professionals and with the relatives. It can be affirmed that therapeutic play allowed for the children's effective communication by expressing their feelings, desires, experiences, criticism against the environment they live in and family relations, besides permitting a moment of pleasure and relaxation.

Differential effects of wakeful rest, music and video game playing on working memory performance in the n-back task

Directory of Open Access Journals (Sweden)

Maxim S Kuschpel

2015-10-01

Full Text Available The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music breaks on working memory performance. Young adults were exposed to breaks involving (i eyes-open resting, (ii listening to music and (iii playing the video game Angry Birds before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the Angry Birds video game during a short learning break led to a decline in task performance over the course of the task as compared to eyes-open resting and listening to music, although overall task performance was not impaired. This effect was associated with high levels of daily mind wandering and low self-reported ability to concentrate. These findings indicate that video games can negatively affect working memory performance over time when played in between learning tasks. We suggest further investigation of these effects because of their relevance to everyday activity.

Differential effects of wakeful rest, music and video game playing on working memory performance in the n-back task.

Science.gov (United States)

Kuschpel, Maxim S; Liu, Shuyan; Schad, Daniel J; Heinzel, Stephan; Heinz, Andreas; Rapp, Michael A

2015-01-01

The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on working memory performance. Young adults were exposed to breaks involving (i) eyes-open resting, (ii) listening to music and (iii) playing the video game "Angry Birds" before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the "Angry Birds" video game during a short learning break led to a decline in task performance over the course of the task as compared to eyes-open resting and listening to music, although overall task performance was not impaired. This effect was associated with high levels of daily mind wandering and low self-reported ability to concentrate. These findings indicate that video games can negatively affect working memory performance over time when played in between learning tasks. We suggest further investigation of these effects because of their relevance to everyday activity.

Differential effects of wakeful rest, music and video game playing on working memory performance in the n-back task

Science.gov (United States)

Kuschpel, Maxim S.; Liu, Shuyan; Schad, Daniel J.; Heinzel, Stephan; Heinz, Andreas; Rapp, Michael A.

2015-01-01

The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on working memory performance. Young adults were exposed to breaks involving (i) eyes-open resting, (ii) listening to music and (iii) playing the video game “Angry Birds” before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the “Angry Birds” video game during a short learning break led to a decline in task performance over the course of the task as compared to eyes-open resting and listening to music, although overall task performance was not impaired. This effect was associated with high levels of daily mind wandering and low self-reported ability to concentrate. These findings indicate that video games can negatively affect working memory performance over time when played in between learning tasks. We suggest further investigation of these effects because of their relevance to everyday activity. PMID:26579055

Characterizing the effects of regolith surface roughness on photoemission from surfaces in space

Science.gov (United States)

Dove, A.; Horanyi, M.; Wang, X.

2017-12-01

Surfaces of airless bodies and spacecraft in space are exposed to a variety of charging environments. A balance of currents due to plasma bombardment, photoemission, electron and ion emission and collection, and secondary electron emission determines the surface's charge. Photoelectron emission is the dominant charging process on sunlit surfaces in the inner solar system due to the intense solar UV radiation. This can result in a net positive surface potential, with a cloud of photoelectrons immediately above the surface, called the photoelectron sheath. Conversely, the unlit side of the body will charge negatively due the collection of the fast-moving solar wind electrons. The interaction of charged dust grains with these positively and negatively charged surfaces, and within the photoelectron and plasma sheaths may explain the occurrence of dust lofting, levitation and transport above the lunar surface. The surface potential of exposed objects is also dependent on the material properties of their surfaces. Composition and particle size primarily affect the quantum efficiency of photoelectron generation; however, surface roughness can also control the charging process. In order to characterize these effects, we have conducted laboratory experiments to examine the role of surface roughness in generating photoelectrons in dedicated laboratory experiments using solid and dusty surfaces of the same composition (CeO2), and initial comparisons with JSC-1 lunar simulant. Using Langmuir probe measurements, we explore the measured potentials above insulating surfaces exposed to UV and an electric field, and we show that the photoemission current from a dusty surface is largely reduced due to its higher surface roughness, which causes a significant fraction of the emitted photoelectrons to be re-absorbed within the surface. We will discuss these results in context of similar situations on planetary surfaces.

Antibacterial effect of silver nanofilm modified stainless steel surface

Science.gov (United States)

Fang, F.; Kennedy, J.; Dhillon, M.; Flint, S.

2015-03-01

Bacteria can attach to stainless steel surfaces, resulting in the colonization of the surface known as biofilms. The release of bacteria from biofilms can cause contamination of food such as dairy products in manufacturing plants. This study aimed to modify stainless steel surfaces with silver nanofilms and to examine the antibacterial effectiveness of the modified surface. Ion implantation was applied to produce silver nanofilms on stainless steel surfaces. 35 keV Ag ions were implanted with various fluences of 1 × 1015 to 1 × 1017 ions•cm-2 at room temperature. Representative atomic force microscopy characterizations of the modified stainless steel are presented. Rutherford backscattering spectrometry spectra revealed the implanted atoms were located in the near-surface region. Both unmodified and modified stainless steel coupons were then exposed to two types of bacteria, Pseudomonas fluorescens and Streptococcus thermophilus, to determine the effect of the surface modification on bacterial attachment and biofilm development. The silver modified coupon surface fluoresced red over most of the surface area implying that most bacteria on coupon surface were dead. This study indicates that the silver nanofilm fabricated by the ion implantation method is a promising way of reducing the attachment of bacteria and delay biofilm formation.

Playful biometrics: controversial technology through the lens of play.

Science.gov (United States)

Ellerbrok, Ariane

2011-01-01

This article considers the role of play in the context of technological emergence and expansion, particularly as it relates to recently emerging surveillance technologies. As a case study, I consider the trajectory of automated face recognition—a biometric technology of numerous applications, from its more controversial manifestations under the rubric of national security to a clearly emerging orientation toward play. This shift toward “playful” biometrics—or from a technology traditionally coded as “hard” to one now increasingly coded as “soft”—is critical insofar as it renders problematic the traditional modes of critique that have, up until this point, challenged the expansion of biometric systems into increasingly ubiquitous realms of everyday life. In response to this dynamic, I propose theorizing the expansion of face recognition specifically in relation to “play,” a step that allows us to broaden the critical space around newly emerging playful biometrics, as well as playful surveillance more generally. In addition, play may also have relevance for theorizing other forms of controversial technology, particularly given its potential role in processes of obfuscation, normalization, and marginalization.

Maternal attitude and child interest in various play activities before and after mother-child play sessions

Directory of Open Access Journals (Sweden)

Soedjatmiko Soedjatmiko

2018-01-01

Full Text Available Background Play stimulates children’s growth and development. When mothers and their children play, a positive attitude from the mother and adequate interest from the child is required. Little is known about the play activities that effectively stimulate such positive maternal attitude and child interest. Objective To assess for associations between various play activities with maternal attitude and child interest before and after mother-child play sessions. Methods Pre-post intervention questionnaires were distributed to mothers before and after playing with their children. Children were aged 1-5 years, from two play sites (in Surabaya and Makassar, and included using purposive sampling. Eight types of toys/play activities were provided. The allocated time for answering the 17-question survey was 15 minutes. Average scores before and after the mother-child play sessions were analyzed using paired T-test. Results We collected 264 valid questionnaires, 235 in Surabaya and 29 in Makassar. Improvement of maternal attitude after the mother-child play session was found in 132 mothers [mean diff. 0.07 (SD 0.42; 95%CI -0.117 to -0.015; P=0.011]. Play activities with significant improvements in maternal attitude were jigsaw puzzle [mean diff. 0.09 (SD 0.66; 95% CI 0.007 to 0.167;P= 0.033, Lego blocks (mean diff.-0.10 (SD 0.69; 95%CI -0.186 to -0.018; P=0.017, mini-gardening (mean diff. -0.15 (SD 0.75; 95%CI -0.238 to -0.057; P=0.002, sandbox [mean diff.-0.24 (SD 0.83; 95%CI -0.339 to – 0.138; P < 0.001], fishing [mean diff. -0.17 (SD 0.68; 95%CI -0.253 to -0.088; P < 0.001], and animal figurines [mean diff. -0.21 (SD 0.75; 95%CI -0.3 to -0.117;P <0.001]. Improvement of child interest was found in 161 children [mean diff. 0.20 (SD 0.52; 95%CI -0.264 to -0.116; P<0.001]. Play activities with significant improvements in child interest were jigsaw puzzle, Lego blocks, origami, mini-gardening, fishing, and animal figurines. Conclusion Some mother

Fair Play: A Study of Scientific Workforce Trainers’ Experience Playing an Educational Video Game about Racial Bias

Science.gov (United States)

Kaatz, Anna; Carnes, Molly; Gutierrez, Belinda; Savoy, Julia; Samuel, Clem; Filut, Amarette; Pribbenow, Christine Maidl

2017-01-01

Explicit racial bias has decreased in the United States, but racial stereotypes still exist and conspire in multiple ways to perpetuate the underparticipation of Blacks in science careers. Capitalizing on the potential effectiveness of role-playing video games to promote the type of active learning required to increase awareness of and reduce subtle racial bias, we developed the video game Fair Play, in which players take on the role of Jamal, a Black male graduate student in science, who experiences discrimination in his PhD program. We describe a mixed-methods evaluation of the experience of scientific workforce trainers who played Fair Play at the National Institutes of Health Division of Training Workforce Development and Diversity program directors’ meeting in 2013 (n = 47; 76% female, n = 34; 53% nonwhite, n = 26). The evaluation findings suggest that Fair Play can promote perspective taking and increase bias literacy, which are steps toward reducing racial bias and affording Blacks equal opportunities to excel in science. PMID:28450447

Effect of a family focused active play intervention on sedentary time and physical activity in preschool children.

Science.gov (United States)

O'Dwyer, Mareesa V; Fairclough, Stuart J; Knowles, Zoe; Stratton, Gareth

2012-10-01

Early childhood provides a window of opportunity for the promotion of physical activity. Given the limited effectiveness of interventions to date, new approaches are needed. Socio-ecological models suggest that involving parents as intervention targets may be effective in fostering healthier lifestyles in children. This study describes the effectiveness of a family-focused 'Active Play' intervention in decreasing sedentary time and increasing total physical activity in preschool children. Seventy-seven families were recruited from 8 randomly selected SureStart children's centres in the North West of England. Centres were randomly assigned to either an intervention (n = 4) or a comparison group (n = 4). Parents and children in the intervention group received a 10-week active play programme delivered by trained active play professionals; this included an activity and educational component. Families in the comparison group were asked to maintain their usual routine. Each participating parent and child wore a uni-axial accelerometer for 7 days at baseline and post-test. Week and weekend day sedentary time and total physical activity adjusted for child- and home- level covariates were analysed using multilevel analyses. Significant intervention effects were observed for sedentary time and physical activity for both week and weekend days. Children in the intervention group engaged in 1.5% and 4.3% less sedentary time during week and weekend days, respectively and 4.5% and 13.1% more physical activity during week and weekend days, respectively than children in the comparison group. Parent's participation in sport and their physical activity levels, child's sex, availability of media in the home and attendance at organised activities were significant predictors of sedentary time and physical activity in this age group. A 10-week family focused active play intervention produced positive changes in sedentary time and total physical activity levels in preschool children

Effects of a Redesigned Classroom on Play Behaviour among Preschool Children

Science.gov (United States)

Acer, Dilek; Gözen, Göksu; Firat, Zehra Saadet; Kefeli, Hatice; Aslan, Büsra

2016-01-01

Current research exists regarding the play behaviour of students in various settings and with varying abilities. Regardless, there needs to be improved understanding of how students' play behaviour is affected when their classroom environment is significantly redesigned. This study examined, over a 21-week period between December 2013 and May…

Effect of surface topography and bioactive properties on early adhesion and growth behavior of mouse preosteoblast MC3T3-E1 cells.

Science.gov (United States)

Li, Na; Chen, Gang; Liu, Jue; Xia, Yang; Chen, Hanbang; Tang, Hui; Zhang, Feimin; Gu, Ning

2014-10-08

The effects of bioactive properties and surface topography of biomaterials on the adhesion and spreading properties of mouse preosteoblast MC3T3-E1 cells was investigated by preparation of different surfaces. Poly lactic-co-glycolic acid (PLGA) electrospun fibers (ES) were produced as a porous rough surface. In our study, coverslips were used as a substrate for the immobilization of 3,4-dihydroxyphenylalanine (DOPA) and collagen type I (COL I) in the preparation of bioactive surfaces. In addition, COL I was immobilized onto porous electrospun fibers surfaces (E-COL) to investigate the combined effects of bioactive molecules and topography. Untreated coverslips were used as controls. Early adhesion and growth behavior of MC3T3-E1 cells cultured on the different surfaces were studied at 6, 12, and 24 h. Evaluation of cell adhesion and morphological changes showed that the all the surfaces were favorable for promoting the adhesion and spreading of cells. CCK-8 assays and flow cytometry revealed that both topography and bioactive properties were favorable for cell growth. Analysis of β1, α1, α2, α5, α10 and α11 integrin expression levels by immunofluorescence, real-time RT-PCR, and Western blot and indicated that surface topography plays an important role in the early stage of cell adhesion. However, the influence of topography and bioactive properties of surfaces on integrins is variable. Compared with any of the topographic or bioactive properties in isolation, the combined effect of both types of properties provided an advantage for the growth and spreading of MC3T3-E1 cells. This study provides a new insight into the functions and effects of topographic and bioactive modifications of surfaces at the interface between cells and biomaterials for tissue engineering.

Spin Hall effect by surface roughness

KAUST Repository

Zhou, Lingjun; Grigoryan, Vahram L.; Maekawa, Sadamichi; Wang, Xuhui; Xiao, Jiang

2015-01-01

induced by surface roughness subscribes only to the side-jump contribution but not the skew scattering. The paradigm proposed in this paper provides the second, not if only, alternative to generate a sizable spin Hall effect.

Screening-induced surface polar optical phonon scattering in dual-gated graphene field effect transistors

Energy Technology Data Exchange (ETDEWEB)

Hu, Bo, E-mail: hubo2011@semi.ac.cn

2015-03-15

The effect of surface polar optical phonons (SOs) from the dielectric layers on electron mobility in dual-gated graphene field effect transistors (GFETs) is studied theoretically. By taking into account SO scattering of electron as a main scattering mechanism, the electron mobility is calculated by the iterative solution of Boltzmann transport equation. In treating scattering with the SO modes, the dynamic dielectric screening is included and compared to the static dielectric screening and the dielectric screening in the static limit. It is found that the dynamic dielectric screening effect plays an important role in the range of low net carrier density. More importantly, in-plane acoustic phonon scattering and charged impurity scattering are also included in the total mobility for SiO{sub 2}-supported GFETs with various high-κ top-gate dielectric layers considered. The calculated total mobility results suggest both Al{sub 2}O{sub 3} and AlN are the promising candidate dielectric layers for the enhancement in room temperature mobility of graphene in the future.

Surface correlation effects in two-band strongly correlated slabs.

Science.gov (United States)

Esfahani, D Nasr; Covaci, L; Peeters, F M

2014-02-19

Using an extension of the Gutzwiller approximation for an inhomogeneous system, we study the two-band Hubbard model with unequal band widths for a slab geometry. The aim is to investigate the mutual effect of individual bands on the spatial distribution of quasi-particle weight and charge density, especially near the surface of the slab. The main effect of the difference in band width is the presence of two different length scales corresponding to the quasi-particle profile of each band. This is enhanced in the vicinity of the critical interaction of the narrow band where an orbitally selective Mott transition occurs and a surface dead layer forms for the narrow band. For the doped case, two different regimes of charge transfer between the surface and the bulk of the slab are revealed. The charge transfer from surface/center to center/surface depends on both the doping level and the average relative charge accumulated in each band. Such effects could also be of importance when describing the accumulation of charges at the interface between structures made of multi-band strongly correlated materials.

The effects of surface treatments on rapid chloride permeability tests

KAUST Repository

Yoon, Seyoon

2012-08-01

Surface treatments are commonly applied to improve the chloride resistance of concrete structures exposed to saline environments. Information on chloride ingress to surface-treated concrete is mostly provided by application of the rapid chloride permeability test (RCPT); this test is short in duration and provides rapid results. This study presents a numerical formulation, based on the extended Nernst-Plank/Poisson (NPP) equation, to model the effect of the surface treatment on a sample tested by RCPT. Predictions of the model are compared to experimental measurements. The simulations show that the results from RCPT, in terms of ionic profiles and measurement of the electric field, are dependent on the effectiveness of surface treatments. During RCPT, highly effective surface treatments cause both cations and anions to flocculate at the interface between the surface treatment and the concrete, creating a local electric field. Our numerical model includes these phenomena and presents a methodology to obtain more accurate diffusivities of the surface-treated- concrete from RCPT. © 2012 Elsevier B.V. All rights reserved.

The effects of surface treatments on rapid chloride permeability tests

KAUST Repository

Yoon, Seyoon; Oh, Sang-gyun; Ha, Juyoung; Monteiro, Paulo M.

2012-01-01

Surface treatments are commonly applied to improve the chloride resistance of concrete structures exposed to saline environments. Information on chloride ingress to surface-treated concrete is mostly provided by application of the rapid chloride permeability test (RCPT); this test is short in duration and provides rapid results. This study presents a numerical formulation, based on the extended Nernst-Plank/Poisson (NPP) equation, to model the effect of the surface treatment on a sample tested by RCPT. Predictions of the model are compared to experimental measurements. The simulations show that the results from RCPT, in terms of ionic profiles and measurement of the electric field, are dependent on the effectiveness of surface treatments. During RCPT, highly effective surface treatments cause both cations and anions to flocculate at the interface between the surface treatment and the concrete, creating a local electric field. Our numerical model includes these phenomena and presents a methodology to obtain more accurate diffusivities of the surface-treated- concrete from RCPT. © 2012 Elsevier B.V. All rights reserved.

Modeling the large-scale effects of surface moisture heterogeneity on wetland carbon fluxes in the West Siberian Lowland

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T. J. Bohn

2013-10-01

Full Text Available We used a process-based model to examine the role of spatial heterogeneity of surface and sub-surface water on the carbon budget of the wetlands of the West Siberian Lowland over the period 1948–2010. We found that, while surface heterogeneity (fractional saturated area had little overall effect on estimates of the region's carbon fluxes, sub-surface heterogeneity (spatial variations in water table depth played an important role in both the overall magnitude and spatial distribution of estimates of the region's carbon fluxes. In particular, to reproduce the spatial pattern of CH4 emissions recorded by intensive in situ observations across the domain, in which very little CH4 is emitted north of 60° N, it was necessary to (a account for CH4 emissions from unsaturated wetlands and (b use spatially varying methane model parameters that reduced estimated CH4 emissions in the northern (permafrost half of the domain (and/or account for lower CH4 emissions under inundated conditions. Our results suggest that previous estimates of the response of these wetlands to thawing permafrost may have overestimated future increases in methane emissions in the permafrost zone.

Surface Aging Effect on Tire/Pavement Noise Medium-Term Evolution in a Medium-Size City

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Víctor F. Vázquez

2018-05-01

Full Text Available This paper presents the geo-referenced acoustical results obtained throughout the close proximity noise (CPX technique carried out on different urban sections included within the 2017 strategic noise mapping (Directive 2002/49/CE in Ciudad Real, a Spanish medium-sized city. The employed methodology quantifies the tire/pavement noise generated in the contact between the tire and the surface of the studied sections. Measurements were carried out in different research campaigns between 2008 and 2015 (medium-term evolution. They give valuable information about the pavement-aging effect on its surface characteristics. Throughout these years, the acoustic situation of these sections has worsened mainly due to surface damage and higher mean profile depth (MPD values, although the performance does not follow the same pattern in every section. The relationships between measured tire/pavement noise and theoretical environmental noise, just due to the geometric spreading of sound energy, is also studied in order to elaborate a simple rolling noise mapping and to assess the environmental noise evolution. Traffic noise plays the main role in the noise registered within the assessed sections, therefore, CPX assessment could be used by local authorities to take decisions regarding urban planning and traffic management, with the aim of reducing noise exposure from traffic.

The effect of playing advergames that promote energy-dense snacks or fruit on actual food intake among children.

Science.gov (United States)

Folkvord, Frans; Anschütz, Doeschka J; Buijzen, Moniek; Valkenburg, Patti M

2013-02-01

Previous studies have focused on the effects of television advertising on the energy intake of children. However, the rapidly changing food-marketing landscape requires research to measure the effects of nontraditional forms of marketing on the health-related behaviors of children. The main aim of this study was to examine the effect of advergames that promote energy-dense snacks or fruit on children's ad libitum snack and fruit consumption and to examine whether this consumption differed according to brand and product type (energy-dense snacks and fruit). The second aim was to examine whether advergames can stimulate fruit intake. We used a randomized between-subject design with 270 children (age: 8-10 y) who played an advergame that promoted energy-dense snacks (n = 69), fruit (n = 67), or nonfood products (n = 65) or were in the control condition (n = 69). Subsequently, we measured the free intake of energy-dense snacks and fruit. The children then completed questionnaire measures, and we weighed and measured them. The main finding was that playing an advergame containing food cues increased general energy intake, regardless of the advertised brand or product type (energy-dense snacks or fruit), and this activity particularly increased the intake of energy-dense snack foods. Children who played the fruit version of the advergame did not eat significantly more fruit than did those in the other groups. The findings suggest that playing advergames that promote food, including either energy-dense snacks or fruit, increases energy intake in children.

Total pollution effect of urban surface runoff.

Science.gov (United States)

Luo, Hongbing; Luo, Lin; Huang, Gu; Liu, Ping; Li, Jingxian; Hu, Sheng; Wang, Fuxiang; Xu, Rui; Huang, Xiaoxue

2009-01-01

For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD (chemical oxygen demand), TSS (total suspend solid), TP (total phosphorus), TN (total nitrogen) and BOD (biochemical oxygen demand). The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters: rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 (mass first flush ratio) and FF30 (first 30% of runoff volume) can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs (best management practices) facilities.

Bacterial resistance of self-assembled surfaces using PPOm-b-PSBMAn zwitterionic copolymer - concomitant effects of surface topography and surface chemistry on attachment of live bacteria.

Science.gov (United States)

Hsiao, Sheng-Wen; Venault, Antoine; Yang, Hui-Shan; Chang, Yung

2014-06-01

Three well-defined diblock copolymers made of poly(sulfobetaine methacrylate) (poly(SBMA)) and poly(propylene oxide) (PPO) groups were synthesized by atom transfer radical polymerization (ATRP) method. They were physically adsorbed onto three types of surfaces having different topography, including smooth flat surface, convex surface, and indented surface. Chemical state of surfaces was characterized by XPS while the various topographies were examined by SEM and AFM. Hydrophilicity of surfaces was dependent on both the surface chemistry and the surface topography, suggesting that orientation of copolymer brushes can be tuned in the design of surfaces aimed at resisting bacterial attachment. Escherichia coli, Staphylococcus epidermidis, Streptococcus mutans and Escherichia coli with green fluorescent protein (E. coli GFP) were used in bacterial tests to assess the resistance to bacterial attachment of poly(SBMA)-covered surfaces. Results highlighted a drastic improvement of resistance to bacterial adhesion with the increasing of poly(SBMA) to PPO ratio, as well as an important effect of surface topography. The chemical effect was directly related to the length of the hydrophilic moieties. When longer, more water could be entrapped, leading to improved anti-bacterial properties. The physical effect impacted on the orientation of the copolymer brushes, as well as on the surface contact area available. Convex surfaces as well as indented surfaces wafer presented the best resistance to bacterial adhesion. Indeed, bacterial attachment was more importantly reduced on these surfaces compared with smooth surfaces. It was explained by the non-orthogonal orientation of copolymer brushes, resulting in a more efficient surface coverage of zwitterionic molecules. This work suggests that not only the control of surface chemistry is essential in the preparation of surfaces resisting bacterial attachment, but also the control of surface topography and orientation of antifouling

The effects of video game play on the characteristics of saccadic eye movements.

Science.gov (United States)

Mack, David J; Ilg, Uwe J

2014-09-01

Video game play has become a common leisure activity all around the world. To reveal possible effects of playing video games, we measured saccades elicited by video game players (VGPs) and non-players (NVGPs) in two oculomotor tasks. First, our subjects performed a double-step task. Second, we asked our subjects to move their gaze opposite to the appearance of a visual target, i.e. to perform anti-saccades. As expected on the basis of previous studies, VGPs had significantly shorter saccadic reaction times (SRTs) than NVGPs for all saccade types. However, the error rates in the anti-saccade task did not reveal any significant differences. In fact, the error rates of VGPs were actually slightly lower compared to NVGPs (34% versus 40%, respectively). In addition, VGPs showed significantly higher saccadic peak velocities in every saccade type compared to NVGP. Our results suggest that faster SRTs in VGPs were associated with a more efficient motor drive for saccades. Taken together, our results are in excellent agreement with earlier reports of beneficial video game effects through the general reduction in SRTs. Our data clearly provides additional experimental evidence for an higher efficiency of the VGPs on the one hand and refutes the notion of a reduced impulse control in VGPs on the other. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of substrate modification on microbial growth on surfaces

International Nuclear Information System (INIS)

Brown, Angela Ann

1998-01-01

The principle aim of the program was to produce a novel, non-leaching antimicrobial surface for commercial development and future use in the liquid food packaging industry. Antimicrobial surfaces which exist presently have been produced to combat the growth of prokaryotic organisms and usually function as slow release systems. A system which could inhibit eukaryotic growth without contaminating the surrounding 'environment' with the inhibitor was considered of great commercial importance. The remit of this study was concerned with creating a surface which could control the growth of eukaryotic organisms found in fruit juice with particular interest in the yeast, Saccharomyces cerevisiae. Putative antimicrobial surfaces were created by the chemical modification of the test substrate polymers; nylon and ethylvinyl alcohol (EVOH). Surfaces were chemically modified by the covalent coupling of antimicrobial agents known to be active against the yeast Saccharomyces cerevisiae as ascertained by the screening process determining the minimum inhibitory concentration (MIC) values of agents in the desired test medium. During the study it was found that a number of surfaces did appear to inhibit yeast growth in fruit juice, however on further investigation the apparent inhibitory effect was discovered to be the result of un-bound material free in the test medium. On removing the possibility of any un-bound material present on the test surface, by a series of surface washings, the inhibitory effect on yeast growth was eliminated. Of the agents tested only one appeared to have an inhibitory effect which could be attributed to a true antimicrobial surface effect, Amical 48. As there is little known about this agent in the literature, its affect on yeast growth was examined and in particular a proposal for the mode of action on yeast is discussed, providing a plausible explanation for the inhibitory effect observed when this agent is covalently immobilised onto nylon. (author)

Assessing the effects of manual dexterity and playing computer games on catheter-wire manipulation for inexperienced operators.

Science.gov (United States)

Alsafi, Z; Hameed, Y; Amin, P; Shamsad, S; Raja, U; Alsafi, A; Hamady, M S

2017-09-01

To investigate the effect of playing computer games and manual dexterity on catheter-wire manipulation in a mechanical aortic model. Medical student volunteers filled in a preprocedure questionnaire assessing their exposure to computer games. Their manual dexterity was measured using a smartphone game. They were then shown a video clip demonstrating renal artery cannulation and were asked to reproduce this. All attempts were timed. Two-tailed Student's t-test was used to compare continuous data, while Fisher's exact test was used for categorical data. Fifty students aged 18-22 years took part in the study. Forty-six completed the task at an average of 168 seconds (range 103-301 seconds). There was no significant difference in the dexterity score or time to cannulate the renal artery between male and female students. Students who played computer games for >10 hours per week had better dexterity scores than those who did not play computer games: 9.1 versus 10.2 seconds (p=0.0237). Four of 19 students who did not play computer games failed to complete the task, while all of those who played computer games regularly completed the task (p=0.0168). Playing computer games is associated with better manual dexterity and ability to complete a basic interventional radiology task for novices. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Modeling Linkages Between Effective Impervious Surface and Urban Vegetation Productivity in Semi-arid Environments

Science.gov (United States)

Shields, C. A.; Tague, C.

2010-12-01

With a majority of the world's population now living in urban areas, the role of vegetation in urban ecosystems warrants increased attention. We address the question of how the fine scale (significantly impact the productivity of vegetation and uptake of C and N. To gain insight into how landscape features influence vegetation productivity, we use a coupled ecohydrogic model to estimate impacts of the amount and arrangement of impervious surfaces on vegetation water use. We use the model to explore how concepts from research in natural semi-arid ecosystems can be applied in the urban context. Ecological research in semi-arid ecosystems has shown that the arrangement of vegetated and bare surfaces plays a key role in regulating both runoff and ecosystem water use and productivity. Systems that include a mixture of bare and vegetated surfaces, for example, tend to show less runoff and more productivity than those with more homogeneous cover. In some instances, patchiness of bare and vegetated surfaces is more important than total vegetated area in determining rates of runoff and vegetation use of rainfall. In an urban context, impervious surfaces can be viewed as analogous to the bare surfaces present in undeveloped ecosystems. We consider not only the total impervious area (TIA), but also the effect of impervious area with a direct hydrologic connection to the stream network, effective impervious area (EIA). While increases in total impervious area (TIA) have been widely shown to impact catchment hydrology, the role of effective impervious area (EIA) has been less extensively studied. A consensus is emerging from the literature that EIA is as important or even more important than TIA as an indicator of catchment response to urbanization. Ecohydrologic models offer a tool to quantify the role of EIA on water availability and plant productivity and demonstrate the potential of urban areas to act as C or N sinks (and minimize the impacts such as increased storm runoff

Stability studies of plasma modification effects of polylactide and polycaprolactone surface layers

Energy Technology Data Exchange (ETDEWEB)

Moraczewski, Krzysztof, E-mail: kmm@ukw.edu.pl [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Stepczyńska, Magdalena [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Malinowski, Rafał [Institute for Engineering of Polymer Materials and Dyes, Marii Skłodowskiej-Curie 55, 87‐100 Toruń (Poland); Rytlewski, Piotr; Jagodziński, Bartłomiej; Żenkiewicz, Marian [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland)

2016-07-30

Highlights: • Plasma modification affects surface roughness, wettability and surface energy. • Polylactide and polycaprolactone aging causes decay of the modification effects. • Changes in the surface characteristic and wettability deterioration were observed. • The decay occurs due to migration of low molecular weight molecules to the surface. • Plasma modification effect lasts longer in the case of polycaprolactone. - Abstract: The article presents results of research on the stability of oxygen plasma modification effects of polylactide and polycaprolactone surface layers. The modified samples were aged for three, six or nine weeks. The studies were carried out using scanning electron microscopy, goniometry and Fourier transform infrared spectroscopy. Studies have shown that the plasma modification has significant impact on the geometric structure and chemical composition of the surface, wettability and surface energy of tested polymers. The modification effects are not permanent. It has been observed that over time the effects of plasma modification fade. Studies have shown that modifying effect lasts longer in the case of polycaprolactone.

Effect of impurities in description of surface nanobubbles

NARCIS (Netherlands)

Das, S.; Snoeijer, Jacobus Hendrikus; Lohse, Detlef

2010-01-01

Surface nanobubbles emerging at solid-liquid interfaces of submerged hydrophobic surfaces show extreme stability and very small (gas-side) contact angles. In a recent paper Ducker [ W. A. Ducker Langmuir 25 8907 (2009)]. conjectured that these effects may arise from the presence of impurities at the

Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

Directory of Open Access Journals (Sweden)

Homayun Mehrabani

2014-09-01

Full Text Available Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g., Antarctic anchor ice, or in environments with moisture and cold air (e.g., plants, intertidal begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We examined sub-polar marine organisms to develop sample textures and screened them for ice formation and accretion in submerged conditions using previous methods for comparison to data for Antarctic organisms. The sub-polar organisms tested were all found to form ice readily. We also screened artificial 3-D printed samples using the same previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. Despite limitations inherent to our techniques, it appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels, Mytilus edulis, or on the spines of the Antarctic sea urchin Sterechinus neumayeri slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams, Saxidomas nuttalli. The geometric dimensions of the features have only a small (∼6% effect on ice formation. Surface texture affects ice formation, but does not explain by itself the large variation in ice formation and species-specific ice resistance observed in other work. This suggests future examination of other factors, such as material elastic properties and surface coatings, and their

Searching for Affective and Cognitive Restoration: Examining the Restorative Effects of Casual Video Game Play.

Science.gov (United States)

Rupp, Michael A; Sweetman, Richard; Sosa, Alejandra E; Smither, Janan A; McConnell, Daniel S

2017-11-01

We investigated the effects of a passive break, relaxation activity, and casual video game on affect, stress, engagement, and cognitive performance. Reducing stress and improving cognitive performance is critical across many domains. Previous studies investigated taking a break, relaxation techniques, or playing a game; however, these methods have not been compared within a single experiment. Participants completed a baseline affective and cognitive assessment (ACA), which included the Positive and Negative Affect Schedule, shortened version of the Dundee Stress State Questionnaire, and backward digit-span. Next, participants completed a vigilance task, followed by another ACA. Participants were then assigned at random to complete a break or relaxation activity or play a casual video game, followed by a final ACA. Participants who played the casual video game exhibited greater engagement and affective restoration than the relaxation condition. The break condition slightly decreased affect and prevented cognitive restoration. Playing a casual video game even briefly can restore individuals' affective abilities, making it a suitable activity to restore mood in response to stress. However, future research is needed to find activities capable of cognitive restoration. Many activities in life require sustained cognitive demand, which are stressful and decrease performance, especially for workers in performance-critical domains. Our research suggests some leisure activities are better than others for restoring fatigued affective processes.

Improving free play skills of severely retarded children.

Science.gov (United States)

Wehman, P; Marchant, J A

1978-02-01

Severely and profoundly retarded children are usually deficient in play skills. Since play facilitates socialization, language, and motor development, it is a vitally improtant skill to acquire. This pilot study examined the effects of a behavioral training program on the autistic, independent, and social types of play of four severely and profoundly retarded children. The training program involved the use of instructions, modeling, physical guidance, and verbal reinforcement. Results indicated that a marked increase in independent and social play occurred with the introduction of the training program with all four children. Occupational therapists can play an increasingly important role in helping educators formulate relevant educational programs for severely retarded children, particularly in the areas of play and motor skill development.

TOOLS FOR COLABORATIVE LEARNING: A ROLE-PLAYING PRACTICE

Directory of Open Access Journals (Sweden)

Marta Ortiz-de-Urbina Criado

2010-11-01

Full Text Available Role-playing is an active participation tool that facilitates cooperative learning. It has also proved to be more effective in developing competencies than traditional methods. This technique is essential to make theory and practice compatible as is required in order to adapt subjects to the new education system based on the Bolonia’s agreement, especially in Social Sciences disciplines. Consequently, the objective of this paper is to show the effect and use of role-playing applied to management area. Therefore, we analyze and design the role-playing, putting it in practice in the classroom in Human Resource Management subject of different academic degrees. To conclude, this paper has shown the importance of role-playing as a learning tool and development of skills like work cooperation, problem and conflict solving, decision making, and managing complex systems.

Children's perspective on the effectiveness of the Playing for Life philosophy in an after-school sport program

OpenAIRE

Ling, Fiona C.M.; Farrow, A.; Farrow, D.; Berry, J.; Polman, Remco C.J.

2016-01-01

The Playing for Life (P4L) philosophy was developed based on the concept of game play. It emphasizes learning through games within the sporting context to promote sports participation. The main aim of the study was to qualitatively evaluate the effectiveness of the P4L philosophy in contributing to enjoyment and in encouraging continued participation in sports. A total of 97 children (aged 5–12 years), who participated in the Active After-school Communities program that adopted the P4L philos...

Effects of titanium surface anodization with CaP incorporation on human osteoblastic response

Science.gov (United States)

OLIVEIRA, Natássia Cristina Martins; MOURA, Camilla Christian Gomes; ZANETTA-BARBOSA, Darceny; MENDONÇA, Daniela Baccelli Silveira; MENDONÇA, Gustavo; DECHICHI, Paula

2015-01-01

In this study we investigated whether anodization with calcium phosphate (CaP) incorporation (Vulcano®) enhances growth factors secretion, osteoblast-specific gene expression, and cell viability, when compared to acid etched surfaces (Porous®) and machined surfaces (Screw®) after 3 and 7 days. Results showed significant cell viability for Porous and Vulcano at day 7, when compared with Screw (p=0.005). At the same time point, significant differences regarding runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and bone sialoprotein (BSP) expression were found for all surfaces (p0.05). Although no significant correlation was found for growth factors secretion and Runx2 expression, a significant positive correlation between this gene and ALP/BSP expression showed that their strong association is independent on the type of surface. The incorporation of CaP affected the biological parameters evaluated similar to surfaces just acid etched. The results presented here support the observations that roughness also may play an important role in determining cell response. PMID:23498218

Elastic layer under axisymmetric indentation and surface energy effects

Science.gov (United States)

Intarit, Pong-in; Senjuntichai, Teerapong; Rungamornrat, Jaroon

2018-04-01

In this paper, a continuum-based approach is adopted to investigate the contact problem of an elastic layer with finite thickness and rigid base subjected to axisymmetric indentation with the consideration of surface energy effects. A complete Gurtin-Murdoch surface elasticity is employed to consider the influence of surface stresses. The indentation problem of a rigid frictionless punch with arbitrary axisymmetric profiles is formulated by employing the displacement Green's functions, derived with the aid of Hankel integral transform technique. The problem is solved by assuming the contact pressure distribution in terms of a linear combination of admissible functions and undetermined coefficients. Those coefficients are then obtained by employing a collocation technique and an efficient numerical quadrature scheme. The accuracy of proposed solution technique is verified by comparing with existing solutions for rigid indentation on an elastic half-space. Selected numerical results for the indenters with flat-ended cylindrical and paraboloidal punch profiles are presented to portray the influence of surface energy effects on elastic fields of the finite layer. It is found that the presence of surface stresses renders the layer stiffer, and the size-dependent behavior of elastic fields is observed in the present solutions. In addition, the surface energy effects become more pronounced with smaller contact area; thus, the influence of surface energy cannot be ignored in the analysis of indentation problem especially when the indenter size is very small such as in the case of nanoindentation.

Longitudinal surface curvature effect in magnetohydrodynamics

International Nuclear Information System (INIS)

Bodas, N.G.

1975-01-01

The two-dimensional motion of an incompressible and electrically conducting fluid past an electrically insulated body surface (having curvature) is studied for a given O(1) basic flow and magnetic field, when (i) the applied magnetic field is aligned with the velocity in the basic flow, and (ii) the applied magnetic field is within the body surface. 01 and 0(Re sup(1/2)) mean the first and second order approximations respectively in an exansion scheme in powers of Resup(-1/2), Re being the Reynolds number). The technique of matched asymptotic expansions is used to solve the problem. The governing partial differential equations to 0(Resup(-1/2)) boundary layer approximation are found to give similarity solutions for a family of surface curvature and pressure gradient distributions in case (i), and for uniform basic flow with analytic surface curvature distributions in case (ii). The equations are solved numerically. In case (i) it is seen that the effect of the magnetic field on the skin-friction- correction due to the curvature is very small. Also the magnetic field at the wall is reduced by the curvature on the convex side. In case (ii) the magnetic field significantly increases the skin-friction-correction due to the curvature. The effect of the magnetic field on the O(1) and O(Resup(-1/2)) skin friction coefficients increases with the increase of the electrical conductivity of the fluid. Also, at higher values of the magnetic pressure, moderate changes in the electrical conductivity do not influence the correction to the skin-friction significantly. (Auth.)

Failure to demonstrate that playing violent video games diminishes prosocial behavior.

Science.gov (United States)

Tear, Morgan J; Nielsen, Mark

2013-01-01

Past research has found that playing a classic prosocial video game resulted in heightened prosocial behavior when compared to a control group, whereas playing a classic violent video game had no effect. Given purported links between violent video games and poor social behavior, this result is surprising. Here our aim was to assess whether this finding may be due to the specific games used. That is, modern games are experienced differently from classic games (more immersion in virtual environments, more connection with characters, etc.) and it may be that playing violent video games impacts prosocial behavior only when contemporary versions are used. Experiments 1 and 2 explored the effects of playing contemporary violent, non-violent, and prosocial video games on prosocial behavior, as measured by the pen-drop task. We found that slight contextual changes in the delivery of the pen-drop task led to different rates of helping but that the type of game played had little effect. Experiment 3 explored this further by using classic games. Again, we found no effect. We failed to find evidence that playing video games affects prosocial behavior. Research on the effects of video game play is of significant public interest. It is therefore important that speculation be rigorously tested and findings replicated. Here we fail to substantiate conjecture that playing contemporary violent video games will lead to diminished prosocial behavior.

Effects of surface treatments on the translucency, opalescence, and surface texture of dental monolithic zirconia ceramics.

Science.gov (United States)

Kim, Hee-Kyung; Kim, Sung-Hun; Lee, Jai-Bong; Ha, Seung-Ryong

2016-06-01

Surface polishing or glazing may increase the appearance of depth of monolithic zirconia restorations. The purpose of this in vitro study was to investigate the effects of surface treatments on the translucency, opalescence, and surface texture of dental monolithic zirconia ceramics. Forty-five monolithic zirconia specimens (16.3×16.4×2.0 mm) were divided into groups I to V, according to the number of colorings each received. Each group was then divided into 3 subgroups (n=3) according to the surface treatment: N=no treatment; P=polished; and G=glazed. CIElab color coordinates were obtained relative to D65 on a reflection spectrophotometer. The translucency parameter (TP) and opalescence parameter (OP) were calculated. One specimen per subgroups I and V was selected for evaluation of surface roughness (Ra) and was examined with scanning electron microscopy (SEM). Data were analyzed with 2-way ANOVA and pairwise comparisons (α=.05). Statistical powers were verified to evaluate results (α=.05). The interaction effects of surface treatments combined with the number of colorings were significant for TP, OP, and Ra (P.05), whereas glazing significantly decreased OP and Ra in most groups. SEM images demonstrated that surface treatments affected the surface texture of monolithic zirconia ceramics. Surface treatments combined with coloring strongly affect the surface texture of dental monolithic zirconia ceramics. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

The benefits of playing video games.

Science.gov (United States)

Granic, Isabela; Lobel, Adam; Engels, Rutger C M E

2014-01-01

Video games are a ubiquitous part of almost all children's and adolescents' lives, with 97% playing for at least one hour per day in the United States. The vast majority of research by psychologists on the effects of "gaming" has been on its negative impact: the potential harm related to violence, addiction, and depression. We recognize the value of that research; however, we argue that a more balanced perspective is needed, one that considers not only the possible negative effects but also the benefits of playing these games. Considering these potential benefits is important, in part, because the nature of these games has changed dramatically in the last decade, becoming increasingly complex, diverse, realistic, and social in nature. A small but significant body of research has begun to emerge, mostly in the last five years, documenting these benefits. In this article, we summarize the research on the positive effects of playing video games, focusing on four main domains: cognitive, motivational, emotional, and social. By integrating insights from developmental, positive, and social psychology, as well as media psychology, we propose some candidate mechanisms by which playing video games may foster real-world psychosocial benefits. Our aim is to provide strong enough evidence and a theoretical rationale to inspire new programs of research on the largely unexplored mental health benefits of gaming. Finally, we end with a call to intervention researchers and practitioners to test the positive uses of video games, and we suggest several promising directions for doing so. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Analysing playing using the note-time playing path.

Science.gov (United States)

de Graaff, Deborah L E; Schubert, Emery

2011-03-01

This article introduces a new method of data analysis that represents the playing of written music as a graph. The method, inspired by Miklaszewski, charts low-level note timings from a sound recording of a single-line instrument using high-precision audio-to-MIDI conversion software. Note onset times of pitch sequences are then plotted against the score-predicted timings to produce a Note-Time Playing Path (NTPP). The score-predicted onset time of each sequentially performed note (horizontal axis) unfolds in performed time down the page (vertical axis). NTPPs provide a visualisation that shows (1) tempo variations, (2) repetitive practice behaviours, (3) segmenting of material, (4) precise note time positions, and (5) time spent on playing or not playing. The NTPP can provide significant new insights into behaviour and cognition of music performance and may also be used to complement established traditional approaches such as think-alouds, interviews, and video coding.

Amphetamine and cocaine suppress social play behavior in rats through distinct mechanisms.

Science.gov (United States)

Achterberg, E J Marijke; Trezza, Viviana; Siviy, Stephen M; Schrama, Laurens; Schoffelmeer, Anton N M; Vanderschuren, Louk J M J

2014-04-01

Social play behavior is a characteristic form of social behavior displayed by juvenile and adolescent mammals. This social play behavior is highly rewarding and of major importance for social and cognitive development. Social play is known to be modulated by neurotransmitter systems involved in reward and motivation. Interestingly, psychostimulant drugs, such as amphetamine and cocaine, profoundly suppress social play, but the neural mechanisms underlying these effects remain to be elucidated. In this study, we investigated the pharmacological underpinnings of amphetamine- and cocaine-induced suppression of social play behavior in rats. The play-suppressant effects of amphetamine were antagonized by the alpha-2 adrenoreceptor antagonist RX821002 but not by the dopamine receptor antagonist alpha-flupenthixol. Remarkably, the effects of cocaine on social play were not antagonized by alpha-2 noradrenergic, dopaminergic, or serotonergic receptor antagonists, administered either alone or in combination. The effects of a subeffective dose of cocaine were enhanced by a combination of subeffective doses of the serotonin reuptake inhibitor fluoxetine, the dopamine reuptake inhibitor GBR12909, and the noradrenaline reuptake inhibitor atomoxetine. Amphetamine, like methylphenidate, exerts its play-suppressant effect through alpha-2 noradrenergic receptors. On the other hand, cocaine reduces social play by simultaneous increases in dopamine, noradrenaline, and serotonin neurotransmission. In conclusion, psychostimulant drugs with different pharmacological profiles suppress social play behavior through distinct mechanisms. These data contribute to our understanding of the neural mechanisms of social behavior during an important developmental period, and of the deleterious effects of psychostimulant exposure thereon.

Soil surface organic layers in Arctic Alaska: spatial distribution, rates of formation, and microclimatic effects

Science.gov (United States)

Baughman, Carson; Mann, Daniel H.; Verbyla, David L.; Kunz, Michael L.

2015-01-01

Organic layers of living and dead vegetation cover the ground surface in many permafrost landscapes and play important roles in ecosystem processes. These soil surface organic layers (SSOLs) store large amounts of carbon and buffer the underlying permafrost and its contained carbon from changes in aboveground climate. Understanding the dynamics of SSOLs is a prerequisite for predicting how permafrost and carbon stocks will respond to warming climate. Here we ask three questions about SSOLs in a representative area of the Arctic Foothills region of northern Alaska: (1) What environmental factors control the thickness of SSOLs and the carbon they store? (2) How long do SSOLs take to develop on newly stabilized point bars? (3) How do SSOLs affect temperature in the underlying ground? Results show that SSOL thickness and distribution correlate with elevation, drainage area, vegetation productivity, and incoming solar radiation. A multiple regression model based on these correlations can simulate spatial distribution of SSOLs and estimate the organic carbon stored there. SSOLs develop within a few decades after a new, sandy, geomorphic surface stabilizes but require 500–700 years to reach steady state thickness. Mature SSOLs lower the growing season temperature and mean annual temperature of the underlying mineral soil by 8 and 3°C, respectively. We suggest that the proximate effects of warming climate on permafrost landscapes now covered by SSOLs will occur indirectly via climate's effects on the frequency, extent, and severity of disturbances like fires and landslides that disrupt the SSOLs and interfere with their protection of the underlying permafrost.

MOTHER-CHILD AND FATHER-CHILD PLAY INTERACTION: THE IMPORTANCE OF PARENTAL PLAYFULNESS AS A MODERATOR OF THE LINKS BETWEEN PARENTAL BEHAVIOR AND CHILD NEGATIVITY.

Science.gov (United States)

Menashe-Grinberg, Atara; Atzaba-Poria, Naama

2017-11-01

Based on the premise that father-child play is an important context for children's development and that fathers "specialize" in play, similarities and differences in the role of playfulness in the father-child and mother-child relationship were examined. Participants in this study included 111 families (children's age: 1-3 years). Father-child and mother-child play interactions were videotaped and coded for parental playfulness, sensitivity, structuring, and nonintrusiveness as well as child negativity. Results indicated that mothers and fathers did not differ in playfulness and that mothers and fathers who were higher in playfulness had children with lower levels of negativity. However, playfulness differently moderated the links between parents' and children's behaviors for mothers and fathers. A double-risk pattern was found for mothers, such that the links between child negativity and maternal sensitivity, structuring, and nonintrusiveness were significant only for the subgroup of mothers with low levels of playfulness. When mothers had high levels of playfulness, these effects were negligible. For fathers, a double-buffer pattern was revealed, indicating that the links between child negativity and paternal sensitivity and structuring were significant only for fathers with high levels of playfulness. When fathers had low levels of playfulness, these effects were negligible. These findings demonstrate the important role that parental playfulness has on parent-child interaction as well as the need to examine moderation patterns separately for fathers and mothers. © 2017 Michigan Association for Infant Mental Health.

Surface effects on the mechanical properties of nanoporous materials

International Nuclear Information System (INIS)

Xia Re; Li Xide; Feng Xiqiao; Qin Qinghua; Liu Jianlin

2011-01-01

Using the theory of surface elasticity, we investigate the mechanical properties of nanoporous materials. The classical theory of porous materials is modified to account for surface effects, which become increasingly important as the characteristic sizes of microstructures shrink to nanometers. First, a refined Timoshenko beam model is presented to predict the effective elastic modulus of nanoporous materials. Then the surface effects on the elastic microstructural buckling behavior of nanoporous materials are examined. In particular, nanoporous gold is taken as an example to illustrate the application of the proposed model. The results reveal that both the elastic modulus and the critical buckling behavior of nanoporous materials exhibit a distinct dependence on the characteristic sizes of microstructures, e.g. the average ligament width.

Surface effects on the mechanical properties of nanoporous materials

Energy Technology Data Exchange (ETDEWEB)

Xia Re [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Li Xide; Feng Xiqiao [AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); Qin Qinghua [School of Engineering, Australian National University, Canberra, ACT 0200 (Australia); Liu Jianlin, E-mail: fengxq@tsinghua.edu.cn [Department of Engineering Mechanics, China University of Petroleum, Qingdao 266555 (China)

2011-07-01

Using the theory of surface elasticity, we investigate the mechanical properties of nanoporous materials. The classical theory of porous materials is modified to account for surface effects, which become increasingly important as the characteristic sizes of microstructures shrink to nanometers. First, a refined Timoshenko beam model is presented to predict the effective elastic modulus of nanoporous materials. Then the surface effects on the elastic microstructural buckling behavior of nanoporous materials are examined. In particular, nanoporous gold is taken as an example to illustrate the application of the proposed model. The results reveal that both the elastic modulus and the critical buckling behavior of nanoporous materials exhibit a distinct dependence on the characteristic sizes of microstructures, e.g. the average ligament width.

Laser-induced novel patterns: As smart strain actuators for new-age dental implant surfaces

International Nuclear Information System (INIS)

Çelen, Serap; Özden, Hüseyin

2012-01-01

Highlights: ► It is time for that paradigm shift and for an exploration of novel surfaces. ► We developed novel 3D smart surfaces as strain actuators by nanosecond laser pulse energies. ► We analyzed these smart surface morphologies using FEM. ► We estimated their internal stiffness values which play a great role on stress shielding effect. ► We gave the optimum operation parameters. - Abstract: Surface morphologies of titanium implants are of crucial importance for long-term mechanical adaptation for following implantation. One major problem is the stress shielding effect which originates from the mismatch of the bone and the implant elasticity. It is time for a paradigm shift and for an exploration of novel smart surfaces to prevent this problem. Several surface treatment methods have traditionally been used to modify the surface morphology of titanium dental implants. The laser micro-machining can be considered as a unique and promising, non-contact, no media, contamination free, and flexible treatment method for modifying surface properties of materials in the biomedical industry. The aim of the present study is two folds; to develop novel 3D smart surfaces which can be acted as strain actuators by nanosecond laser pulse energies and irradiation strategies. And analyze these smart surface morphologies using finite element methods in order to estimate their internal stiffness values which play a great role on stress shielding effect. Novel 3D smart strain actuators were prepared using an ytterbium fiber laser (λ = 1060 nm) with 200–250 ns pulse durations on commercial pure titanium dental implant material specimen surfaces and optimum operation parameters were suggested.

A method to evaluate the effect of contact with excipients on the surface crystallization of amorphous drugs.

Science.gov (United States)

Zhang, Si-Wei; Yu, Lian; Huang, Jun; Hussain, Munir A; Derdour, Lotfi; Qian, Feng; de Villiers, Melgardt M

2014-12-01

Amorphous drugs are used to improve the solubility, dissolution, and bioavailability of drugs. However, these metastable forms of drugs can transform into more stable, less soluble, crystalline counterparts. This study reports a method for evaluating the effect of commonly used excipients on the surface crystallization of amorphous drugs and its application to two model amorphous compounds, nifedipine and indomethacin. In this method, amorphous samples of the drugs were covered by excipients and stored in controlled environments. An inverted light microscope was used to measure in real time the rates of surface crystal nucleation and growth. For nifedipine, vacuum-dried microcrystalline cellulose and lactose monohydrate increased the nucleation rate of the β polymorph from two to five times when samples were stored in a desiccator, while D-mannitol and magnesium stearate increased the nucleation rate 50 times. At 50% relative humidity, the nucleation rates were further increased, suggesting that moisture played an important role in the crystallization caused by the excipients. The effect of excipients on the crystal growth rate was not significant, suggesting that contact with excipients influences the physical stability of amorphous nifedipine mainly through the effect on crystal nucleation. This effect seems to be drug specific because for two polymorphs of indomethacin, no significant change in the nucleation rate was observed under the excipients.

Effects of e-learning, lectures, and role playing on nursing students' knowledge acquisition, retention and satisfaction.

Science.gov (United States)

Pourghaznein, Tayebeh; Sabeghi, Hakimeh; Shariatinejad, Keyvan

2015-01-01

Nursing education can maintain its dynamic quality when it moves toward innovation and modern methods of teaching and learning. Therefore, teachers are required to employ up to date methods in their teaching plans. This study evaluated the effects of e-learning, lectures, and role playing on nursing students' learning, retention, and satisfaction. Sixty nursing students were selected as an experiment and control groups during two consecutive semesters. The educational content was presented as e-learning and role playing during one semester (experiment group) and as lectures in the next semester (control group). A questionnaire containing three parts was used to assess demographics, learning and satisfaction statuses. The questionnaire also included a final openended question to evaluate the students' ideas about the whole course. The mean scores of posttest were 16.13 ± 1.37 using role playing, 15.50 ± 1.44 using e-learning and 16.45 ± 1.23 using lectures. The differences between the mean scores of posttest and pretest were 12.84 ± 1.43, 12.56 ± 1.57, and 13.73 ± 1.53 in the mentioned methods, respectively. Lectures resulted in significantly better learning compared to role playing and e-learning. In contrast, retention rates were significantly lower using lectures than using role playing and e-learning. Students' satisfaction from e-learning was significantly lower than lecturing and role playing. Due to the lower rates of retention following lectures, the teachers are recommended to use student- centered approaches in their lectures. Since students' satisfaction with e-learning was lower than the other methods, further studies are suggested to explore the problems of e-learning in Iran.

Surface chemistry essentials

CERN Document Server

Birdi, K S

2013-01-01

Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

Effect of surface wettability caused by radiation induced surface activation on leidenfrost condition

International Nuclear Information System (INIS)

Takamasa, T.; Hazuku, T.; Tamura, N.; Okamoto, K.; Mishima, K.; Furuya, M.

2003-01-01

Improving the limit of boiling heat transfer or critical heat flux requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. From this basis, we investigated surface wettability and Leidenfrost condition using metal oxides irradiated by γ-rays. In our previous study, contact angle, an indicator of macroscopic wettability, of a water droplet on metal oxide at room temperature was measured by image processing of the images obtained by a CCD video camera. The results showed that the surface wettability on metal oxide pieces of titanium, Zircaloy No. 4, SUS-304, and copper was improved significantly by the Radiation Induced Surface Activation (RISA) phenomenon. To delineate the effect of Radiation Induced Surface Activation (RISA) on heat transferring phenomena, the Leidenfrost condition and quenching of metal oxides irradiated by γ-rays were investigated. In the Leidenfrost experiment, when the temperature of the heating surface reached the wetting limit temperature, water-solid contact vanished because a stable vapor film existed between the droplet and the metal surface; i.e., a Leidenfrost condition obtained. The wetting limit temperature increased with integrated irradiation dose. After irradiation, the wet length and the duration of contact increased, and the contact angle decreased. In the quenching test, high surface wettability, or a highly hydrophilic condition, of a simulated fuel rod made of SUS was achieved, and the quenching velocities were increased up to 20-30% after 300 kGy 60Co γ-ray irradiation

Effect of surface wettability caused by radiation induced surface activation on leidenfrost condition

Energy Technology Data Exchange (ETDEWEB)

Takamasa, T.; Hazuku, T.; Tamura, N.; Okamoto, K. [Tokyo Univ., Tokyo (Japan); Mishima, K. [Kyoto Univ., Kyoto (Japan); Furuya, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

2003-07-01

Improving the limit of boiling heat transfer or critical heat flux requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. From this basis, we investigated surface wettability and Leidenfrost condition using metal oxides irradiated by {gamma}-rays. In our previous study, contact angle, an indicator of macroscopic wettability, of a water droplet on metal oxide at room temperature was measured by image processing of the images obtained by a CCD video camera. The results showed that the surface wettability on metal oxide pieces of titanium, Zircaloy No. 4, SUS-304, and copper was improved significantly by the Radiation Induced Surface Activation (RISA) phenomenon. To delineate the effect of Radiation Induced Surface Activation (RISA) on heat transferring phenomena, the Leidenfrost condition and quenching of metal oxides irradiated by {gamma}-rays were investigated. In the Leidenfrost experiment, when the temperature of the heating surface reached the wetting limit temperature, water-solid contact vanished because a stable vapor film existed between the droplet and the metal surface; i.e., a Leidenfrost condition obtained. The wetting limit temperature increased with integrated irradiation dose. After irradiation, the wet length and the duration of contact increased, and the contact angle decreased. In the quenching test, high surface wettability, or a highly hydrophilic condition, of a simulated fuel rod made of SUS was achieved, and the quenching velocities were increased up to 20-30% after 300 kGy 60Co {gamma}-ray irradiation.

Playing with Protons CREATIONS Demonstrator

CERN Multimedia

Alexopoulos, Angelos

2017-01-01

This document describes Playing with Protons, a CMS education initiative that seeks to enhance teachers’ pedagogical practice with creative, hands-on methodologies through which 10-12 year old students can, in turn, get engaged effectively with science, technology and innovation.

Effect of impact surface in equestrian falls

OpenAIRE

Clark, J. Michio; Post, Andrew; Connor, Thomas A.; Hoshizaki, Thomas Blaine; Gilchrist, M. D.

2016-01-01

This study examines the effect of impact surface on head kinematic response and maximum principal strain (MPS) for equestrian falls. A helmeted Hybrid III headform was dropped unrestrained onto three impact surfaces of different stiffness (steel, turf and sand) and three locations. Peak resultant linear acceleration, rotational acceleration and duration of the impact events were measured. A finite element brain model was used to calculate MPS. The results revealed that drops onto steel produc...

The Effectiveness of Cognitive-Behavioral Play Therapy on Externalizing Behavior Problems Among Street and Working Children

Directory of Open Access Journals (Sweden)

Niloofar Ghodousi

2017-11-01

Discussion: It seems that one of the effective ways to lessen externalizing behavior problems among street and working children is cognitive-behavioral play therapy; therefore, coaches and teachers of such children are recommended to make use of this method to lower their behavioral problems. 

Synergistic effect of wire bending and salivary pH on surface properties and mechanical properties of orthodontic stainless steel archwires.

Science.gov (United States)

Hobbelink, Marieke G; He, Yan; Xu, Jia; Xie, Huixu; Stoll, Richard; Ye, Qingsong

2015-01-01

The aim of this study was to investigate the corrosive behaviour of stainless steel archwires in a more clinically relevant way by bending and exposing to various pH. One hundred and twenty pieces of rectangular stainless steel wires (0.43 × 0.64 mm) were randomly assigned into four groups. In each group, there were 15 pieces of bent wires and 15 straight ones. Prior to measurements of the wires, as individual experimental groups (group 1, 2, and 3), the wires were exposed to artificial saliva for 4 weeks at pH 5.6, 6.6, and 7.6, respectively. A control group of wires (group 4) remained in air for the same period of time before sent for measurements. Surface roughness (Ra-value) was measured by a profilometer. Young's modulus and maximum force were determined by a four-point flexural test apparatus. Scanning electron microscopy was used to observe the surface morphology of straight wire. Differences between groups were examined using a two-way analysis of variance (ANOVA). Mean surface roughness values, flexural Young's moduli, and maximum force values of bent wires are significantly different from those of the straight wires, which was the main effect of wire bending, ignoring the influence of pH. A significant effect was found between Ra-values regarding the main effect of pH, ignoring the influence of shape. There was a significant interaction effect of bending and pH on flexural Young's moduli of stainless steel archwires, while pH did not show much impact on the maximum force values of those stainless steel wires. Bigger surface irregularities were seen on SEM images of straight wires immersed in artificial saliva at pH 5.6 compared to artificial saliva at other pH values. Surface depth (Rz) was more sensitive than Ra in revealing surface roughness, both measured from 3D reconstructed SEM images. Ra showed a comparable result of surface roughness to Ra-value measured by the profilometer. Bending has a significant influence on surface roughness and mechanical

Learning Arabic through play

DEFF Research Database (Denmark)

Papadopoulos, Pantelis M.; Ibrahim, Zeinab; Karatsolis, Andreas

2015-01-01

This paper presents the use of educational games in the context of the “Arabiyyatii” research project, a three-year project funded through Qatar National Research Fund. The scope of the project is teaching Modern Standard Arabic (MSA) to kindergarten students (5-6 years old) that are native...... speakers of the Qatari dialect. Part of the new curriculum envisioned in the project includes the use of simple educational games, specifically designed and developed for tabletop surface computers. The paper presents a naturalistic study design, following the activities of 18 students for a period of 9...... weeks in the project. The paper presents three of the most played games by the students, along with analysis on collected data, focusing on students’ performance and attitudes towards the new curriculum. Results analysis provided an encouraging image, suggesting that the conducted activity was able...

Teaching communication skills to hospice teams: comparing the effectiveness of a communication skills laboratory with in-person, second life, and phone role-playing.

Science.gov (United States)

Hamilton, Gillian; Ortega, Rosio; Hochstetler, Vicki; Pierson, Kristen; Lin, Peiyi; Lowes, Susan

2014-09-01

Communication skills are critical in hospice care but challenging to teach. Therefore, a hospice agency developed a communication skills laboratory for nurses and social workers. Learners role-played 3 common hospice scenarios. The role-play modalities were in-person, Second Life, and telephone. Learners were scored on 4 communication aspects. Learners in all modalities rated the laboratory as very effective. However, learners in the Second Life and phone modality showed greater improvements from scene 1 to 3 than those in the in-person modality. There were no significant differences in improvement between the Second Life and phone modalities. Results support the effectiveness of this communication skills laboratory while using different teaching modalities and show phone and Second Life role-plays were more effective than an in-person role-play. © The Author(s) 2013.

Early Social Fear in Relation to Play with an Unfamiliar Peer: Actor and Partner Effects

Science.gov (United States)

Walker, Olga L.; Degnan, Kathryn A.; Fox, Nathan A.; Henderson, Heather A.

2015-01-01

The purpose of this study was to examine the associations between maternal reports of social fear at 24 months and social behaviors with an unfamiliar peer during play at 36 months, using the Actor-Partner Interdependence Model (APIM; Kashy & Kenny, 1999). The APIM model was used to not only replicate previous findings of direct effects of…

Different effects of surface heterogeneous atoms of porous and non-porous carbonaceous materials on adsorption of 1,1,2,2-tetrachloroethane in aqueous environment.

Science.gov (United States)

Chen, Weifeng; Ni, Jinzhi

2017-05-01

The surface heterogeneous atoms of carbonaceous materials (CMs) play an important role in adsorption of organic pollutants. However, little is known about the surface heterogeneous atoms of CMs might generate different effect on adsorption of hydrophobic organic compounds by porous carbonaceous materials - activated carbons (ACs) and non-porous carbonaceous materials (NPCMs). In this study, we observed that the surface oxygen and nitrogen atoms could decrease the adsorption affinity of both ACs and NPCMs for 1,1,2,2-tetrachloroethane (TeCA), but the degree of decreasing effects were very different. The increasing content of surface oxygen and nitrogen ([O + N]) caused a sharper decrease in adsorption affinity of ACs (slope of lg (k d /SA) vs [O + N]: -0.098∼-0.16) than that of NPCMs (slope of lg (k d /SA) vs [O + N]: -0.025∼-0.059) for TeCA. It was due to the water cluster formed by the surface hydrophilic atoms that could block the micropores and generate massive invalid adsorption sites in the micropores of ACs, while the water cluster only occupied the surface adsorption sites of NPCMs. Furthermore, with the increasing concentration of dissolved TeCA, the effect of surface area on adsorption affinity of NPCMs for TeCA kept constant while the effect of [O + N] decreased due to the competitive adsorption between water molecule and TeCA on the surface of NPCMs, meanwhile, both the effects of micropore volume and [O + N] on adsorption affinity of ACs for TeCA were decreased due to the mechanism of micropore volume filling. These findings are valuable for providing a deep insight into the adsorption mechanisms of CMs for TeCA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of leaf area index on the coupling between water table, land surface energy fluxes, and planetary boundary layer at the regional scale

Science.gov (United States)

Lu, Y.; Rihani, J.; Langensiepen, M.; Simmer, C.

2013-12-01

Vegetation plays an important role in the exchange of moisture and energy at the land surface. Previous studies indicate that vegetation increases the complexity of the feedbacks between the atmosphere and subsurface through processes such as interception, root water uptake, leaf surface evaporation, and transpiration. Vegetation cover can affect not only the interaction between water table depth and energy fluxes, but also the development of the planetary boundary layer. Leaf Area Index (LAI) is shown to be a major factor influencing these interactions. In this work, we investigate the sensitivity of water table, surface energy fluxes, and atmospheric boundary layer interactions to LAI as a model input. We particularly focus on the role LAI plays on the location and extent of transition zones of strongest coupling and how this role changes over seasonal timescales for a real catchment. The Terrestrial System Modelling Platform (TerrSysMP), developed within the Transregional Collaborative Research Centre 32 (TR32), is used in this study. TerrSysMP consists of the variably saturated groundwater model ParFlow, the land surface model Community Land Model (CLM), and the regional climate and weather forecast model COSMO (COnsortium for Small-scale Modeling). The sensitivity analysis is performed over a range of LAI values for different vegetation types as extracted from the Moderate Resolution Imaging Spectroradiometer (MODIS) dataset for the Rur catchment in Germany. In the first part of this work, effects of vegetation structure on land surface energy fluxes and their connection to water table dynamics are studied using the stand-alone CLM and the coupled subsurface-surface components of TerrSysMP (ParFlow-CLM), respectively. The interconnection between LAI and transition zones of strongest coupling are investigated and analyzed through a subsequent set of subsurface-surface-atmosphere coupled simulations implementing the full TerrSysMP model system.

Concepts of Play and Play Culture for the 21st Century

DEFF Research Database (Denmark)

Nørgård, Rikke Toft; Toft, Herdis; Karoff, Helle Skovbjerg

2014-01-01

, Associate professor Carsten Jessen, Aarhus University, Assistant professor Helle Skovbjerg Karoff, University of Aalborg and Assistant professor Rikke Toft Nørgård, Aarhus University. This panel represents and discusses different concepts of play and play culture in both diachronic and synchronic dimensions......BIN Norden conference 2014 Accepted panel ________________________________________ Concepts of Play and Play Culture for the 21st Century Participants in the panel are: Associate professor Herdis Toft, University of Southern Denmark (organizer), Professor Beth Juncker, University of Copenhagen....... For several centuries western theorists, for instance Baumgarten, Schiller, Huizinga, Caillois, Sutton Smith, Vygotsky, Bateson, Salen & Zimmerman, Flemming Mouritsen and later on the panel participants, have discussed the concept of play and play culture. They have presented their own theoretical...

Effects of a single-session assertiveness music therapy role playing protocol for psychiatric inpatients.

Science.gov (United States)

Silverman, Michael J

2011-01-01

The purpose of this study was to implement and measure the effectiveness of a single-session assertiveness music therapy role playing protocol for psychiatric inpatients. Participants (N=133) were randomly assigned by group to one of three conditions: (a) Assertiveness Music Therapy, (b) No Music Assertiveness, or (c) Music No Assertiveness. Participants in both assertiveness conditions role played a number of different commonly occurring scenarios at an inpatient psychiatric facility and in the community. There were no significant between-group differences in posttest quality of life, locus of control, or other subscales. However, participants in both assertiveness conditions tended to have slightly higher internal locus of control and overall quality of life scores than participants in the music no assertiveness condition. Additionally, the assertiveness music therapy condition had higher attendance rates than the other conditions. A higher percentage of participants from both the assertiveness music therapy and music no assertiveness conditions indicated they thought their session was the most helpful/therapeutic group therapy session in which they had participated; this was not the case for the assertiveness no music condition. Future research is warranted to measure the effects of protocols that can help psychiatric patients generalize skills learned in treatment.

Failure to demonstrate that playing violent video games diminishes prosocial behavior.

Directory of Open Access Journals (Sweden)

Morgan J Tear

Full Text Available BACKGROUND: Past research has found that playing a classic prosocial video game resulted in heightened prosocial behavior when compared to a control group, whereas playing a classic violent video game had no effect. Given purported links between violent video games and poor social behavior, this result is surprising. Here our aim was to assess whether this finding may be due to the specific games used. That is, modern games are experienced differently from classic games (more immersion in virtual environments, more connection with characters, etc. and it may be that playing violent video games impacts prosocial behavior only when contemporary versions are used. METHODS AND FINDINGS: Experiments 1 and 2 explored the effects of playing contemporary violent, non-violent, and prosocial video games on prosocial behavior, as measured by the pen-drop task. We found that slight contextual changes in the delivery of the pen-drop task led to different rates of helping but that the type of game played had little effect. Experiment 3 explored this further by using classic games. Again, we found no effect. CONCLUSIONS: We failed to find evidence that playing video games affects prosocial behavior. Research on the effects of video game play is of significant public interest. It is therefore important that speculation be rigorously tested and findings replicated. Here we fail to substantiate conjecture that playing contemporary violent video games will lead to diminished prosocial behavior.

Failure to Demonstrate That Playing Violent Video Games Diminishes Prosocial Behavior

Science.gov (United States)

Tear, Morgan J.; Nielsen, Mark

2013-01-01

Background Past research has found that playing a classic prosocial video game resulted in heightened prosocial behavior when compared to a control group, whereas playing a classic violent video game had no effect. Given purported links between violent video games and poor social behavior, this result is surprising. Here our aim was to assess whether this finding may be due to the specific games used. That is, modern games are experienced differently from classic games (more immersion in virtual environments, more connection with characters, etc.) and it may be that playing violent video games impacts prosocial behavior only when contemporary versions are used. Methods and Findings Experiments 1 and 2 explored the effects of playing contemporary violent, non-violent, and prosocial video games on prosocial behavior, as measured by the pen-drop task. We found that slight contextual changes in the delivery of the pen-drop task led to different rates of helping but that the type of game played had little effect. Experiment 3 explored this further by using classic games. Again, we found no effect. Conclusions We failed to find evidence that playing video games affects prosocial behavior. Research on the effects of video game play is of significant public interest. It is therefore important that speculation be rigorously tested and findings replicated. Here we fail to substantiate conjecture that playing contemporary violent video games will lead to diminished prosocial behavior. PMID:23844191

Effects on energetic impact of atomic clusters with surfaces

International Nuclear Information System (INIS)

Popok, V.N.; Vuchkovich, S.; Abdela, A.; Campbell, E.E.B.

2007-01-01

A brief state-of-the-art review in the field of cluster ion interaction with surface is presented. Cluster beams are efficient tools for manipulating agglomerates of atoms providing control over the synthesis as well as modification of surfaces on the nm-scale. The application of cluster beams for technological purposes requires knowledge of the physics of cluster-surface impact. This has some significant differences compared to monomer ion - surface interactions. The main effects of cluster-surface collisions are discussed. Recent results obtained in experiments on silicon surface nanostructuring using keV-energy implantation of inert gas cluster ions are presented and compared with molecular dynamics simulations. (authors)

Immobilization of β-galactosidase from Kluyveromyces lactis onto polymeric membrane surfaces: effect of surface characteristics.

Science.gov (United States)

Güleç, Hacı Ali

2013-04-01

The aim of this study was to investigate the effects of surface characteristics of plain and plasma modified cellulose acetate (CA) membranes on the immobilization yield of β-galactosidases from Kluyveromyces lactis (KLG) and its galacto-oligosaccharide (GOS) yield, respectively. Low pressure plasma treatments involving oxygen plasma activation, plasma polymerization (PlsP) of ethylenediamine (EDA) and PlsP of 2-mercaptoethanol were used to modify plain CA membrane surfaces. KLG enzyme was immobilized onto plain and oxygen plasma treated membrane surfaces by simple adsorption. Oxygen plasma activation increased the hydrophylicity of CA membrane surfaces and it improved the immobilization yield of the enzyme by 42%. KLG enzyme was also immobilized onto CA membrane surfaces through amino groups created by PlsP of EDA via covalent binding. Plasma action at 60W plasma power and 15 min. exposure time improved the amount of membrane bounded enzyme by 3.5-fold. The enrichment of the amount of amino groups via polyethyleneimine (PEI) addition enhanced this increase from 3.5-fold to 4.5-fold. Although high enzyme loading was achived (65-83%), both of the methods dramatically decreased the enzyme activity (11-12%) and GOS yield due to probably negative effects of active amino groups. KLG enzyme was more effectively immobilized onto thiolated CA membrane surface created by PlsP of 2-mercaptoethanol with high immobilization yield (70%) and especially high enzyme activity (46%). Immobilized enzymes on the CA membranes treated by PlsP were successively reutilized for 5-8 cycles at 25°C and enzymatic derivatives retained approximately 75-80% of their initial activites at the end of the reactions. Copyright © 2012 Elsevier B.V. All rights reserved.

Playing on the edge

DEFF Research Database (Denmark)

Cermak-Sassenrath, Daniel

2018-01-01

and specific ways. For instance, gambling for money, party and drinking games, professional play and show sports, art installations, violent and military propaganda computer games, pervasive/mobile gaming, live-action role playing, festivals, performances, and games such as Ghosting and Planking. It is argued......Everything gets more interesting, challenging, or intense the closer it gets to the edge, and so does play. How edgy can play become and still be play? Based on Huizinga’s notion of play, this chapter discusses how a wide range of playful activities pushes the boundaries of play in different...... that in concert with a number of characteristics that mark an activity as play, play is essentially a subjective perspective and individual decision of the player. Huizinga calls this attitude the play spirit, which informs a player’s actions and is in turn sustained by them. Edgy digital or mobile games do...

Play Therapy: A Review

Science.gov (United States)

Porter, Maggie L.; Hernandez-Reif, Maria; Jessee, Peggy

2009-01-01

This article discusses the current issues in play therapy and its implications for play therapists. A brief history of play therapy is provided along with the current play therapy approaches and techniques. This article also touches on current issues or problems that play therapists may face, such as interpreting children's play, implementing…

Well Played: The Origins and Future of Playfulness

Science.gov (United States)

Gordon, Gwen

2014-01-01

In this article, the author synthesizes research from several disciplines to shed light on play's central role in healthy development. Gordon builds on research in attachment theory that correlates secure attachment in infancy with adult well-being to demonstrate how playfulness might be a lifelong outcome of secure attachment and a primary…

Effect of remote clouds on surface UV irradiance

Energy Technology Data Exchange (ETDEWEB)

Deguenther, M.; Meerkoetter, R. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

2000-06-01

Clouds affect local surface UV irradiance, even if the horizontal distance from the radiation observation site amounts to several kilometers. In order to investigate this effect, which we call remote clouds effect, a 3-dimensional radiative transfer model is applied. Assuming the atmosphere is subdivided into a quadratic based sector and its surrounding, we quantify the influence of changing cloud coverage within this surrounding from 0% to 100% on surface UV irradiance at the sector center. To work out this remote clouds influence as a function of sector base size, we made some calculations for different sizes between 10 km x 10 km and 100 km x 100 km. It appears that in the case of small sectors (base size {<=}20 km x 20 km) the remote clouds effect is highly variable: Depending on cloud structure, solar zenith angle and wavelength, the surface UV irradiance may be enhanced up to 15% as well as reduced by more than 50%. In contrast, for larger sectors it is always the case that enhancements become smaller by 5% if sector base size exceeds 60 km x 60 km. However, these values are upper estimates of the remote cloud effects and they are found only for special cloud structures. Since these structures might occur but cannot be regarded as typical, different satellite observed cloud formations (horizontal resolution about 1 km x 1 km) have also been investigated. For these more common cloud distributions we find remote cloud effects to be distinctly smaller than the corresponding upper estimates, e.g., for a sector with base size of 25 km x 25 km the surface UV irradiance error due to ignoring the actual remote clouds and replacing their influence with periodic horizontal boundary conditions is less than 3%, whereas the upper estimate of remote clouds effect would suggest an error close to 10%. (orig.)

The LapG protein plays a role in Pseudomonas aeruginosa biofilm formation by controlling the presence of the CdrA adhesin on the cell surface

DEFF Research Database (Denmark)

Rybtke, Morten; Berthelsen, Jens; Yang, Liang

2015-01-01

Pseudomonas aeruginosa is a clinically relevant species involved in biofilm-based chronic infections. We provide evidence that the P. aeruginosa LapG protein functions as a periplasmic protease that can cleave the protein adhesin CdrA off the cell surface, and thereby plays a role in biofilm...... formation and biofilm dispersal. The P. aeruginosa LapG protein is shown to be a functional homolog of the Pseudomonas putida LapG protein which has previously been shown to function as a periplasmic protease that targets the surface adhesin LapA. Transposon mutagenesis and characterization of defined...... and whole-cell protein fractions showed that CdrA was retained in the whole-cell protein fraction when LapG was absent, whereas it was found in the culture supernatant when LapG was present. The finding that CdrA is a target of LapG in P. aeruginosa is surprising because CdrA has no homology to LapA....

Depression and play in early childhood. Play behavior of depressed and nondepressed 3- to 6-year olds in various play situations

NARCIS (Netherlands)

Mol Lous, A.; Wit, C.A.M. de; Bruyn, E.E.J. De; Riksen-Walraven, J.M.A.; Rost, H.

2000-01-01

The behavior of seven depressed and seven nondepressed 3- to 6-year-olds was compared in three play situations: solitary free play, interactive free play, and play narratives. Depressed children played significantly less than their nondepressed controls. This was mainly due to differences in

Video Game Playing Effects on Obesity in an Adolescent with Autism Spectrum Disorder: A Case Study

Directory of Open Access Journals (Sweden)

Brandy E. Strahan

2015-01-01

Full Text Available Adolescent obesity has tripled in the past two decades, and adolescents with disabilities, specifically autism spectrum disorders (ASD, may be at greater risk for obesity due to the behavioral, physical, and psychosocial complications related to their disorder. This case study reports the effects of video game playing on an obese adolescent with ASD and illustrates the use of a multiple baseline single subject design. Over 12 weeks, the participant played inactive (6 weeks and active video games (6 weeks on the Wii console. Physiological data were evaluated weekly at home. Stress and anxiety were measured via the Stress Survey Schedule for Individuals with Autism and Other Pervasive Non-Developmental Disorders (SSS and the Behavior Assessment System for Children Second Edition (BASC-2 pre- and postintervention. The Therapy Attitude Inventory (TAI was used to determine parental perception of video game playing as a socially valid intervention to reduce stress and anxiety. Results demonstrated that active video game playing slowed and/or reduced weight and BMI with minimal changes to waist-to-hip ratios, triceps skinfolds, and stress and anxiety. This study demonstrates how alternative methods for physical activity may be used to improve health outcomes of overweight/obese adolescents with ASD and suggests directions for future research.

Numerical analysis of the bucket surface roughness effects in Pelton turbine

International Nuclear Information System (INIS)

Xiao, Y X; Zeng, C J; Zhang, J; Yan, Z G; Wang, Z W

2013-01-01

The internal flow of a Pelton turbine is quite complex. It is difficult to analyse the unsteady free water sheet flow in the rotating bucket owing to the lack of a sound theory. Affected by manufacturing technique and silt abrasion during the operation, the bucket surface roughness of Pelton turbine may be too great, and thereby influence unit performance. To investigate the effect of bucket roughness on Pelton turbine performance, this paper presents the numerical simulation of the interaction between the jet and the bucket in a Pelton turbine. The unsteady three-dimensional numerical simulations were performed with CFX code by using the SST turbulence model coupling the two-phase flow volume of fluid method. Different magnitude orders of bucket surface roughness were analysed and compared. Unsteady numerical results of the free water sheet flow patterns on bucket surface, torque and unit performance for each bucket surface roughness were generated. The total pressure distribution on bucket surface is used to show the free water sheet flow pattern on bucket surface. By comparing the variation of water sheet flow patterns on bucket surface with different roughness, this paper qualitatively analyses how the bucket surface roughness magnitude influences the impeding effect on free water sheet flow. Comparison of the torque variation of different bucket surface roughness highlighted the effect of the bucket surface roughness on the Pelton turbine output capacity. To further investigate the effect of bucket surface roughness on Pelton turbine performance, the relation between the relative efficiency loss rate and bucket surface roughness magnitude is quantitatively analysed. The result can be used to predict and evaluate the Pelton turbine performance

Numerical analysis of the bucket surface roughness effects in Pelton turbine

Science.gov (United States)

Xiao, Y. X.; Zeng, C. J.; Zhang, J.; Yan, Z. G.; Wang, Z. W.

2013-12-01

The internal flow of a Pelton turbine is quite complex. It is difficult to analyse the unsteady free water sheet flow in the rotating bucket owing to the lack of a sound theory. Affected by manufacturing technique and silt abrasion during the operation, the bucket surface roughness of Pelton turbine may be too great, and thereby influence unit performance. To investigate the effect of bucket roughness on Pelton turbine performance, this paper presents the numerical simulation of the interaction between the jet and the bucket in a Pelton turbine. The unsteady three-dimensional numerical simulations were performed with CFX code by using the SST turbulence model coupling the two-phase flow volume of fluid method. Different magnitude orders of bucket surface roughness were analysed and compared. Unsteady numerical results of the free water sheet flow patterns on bucket surface, torque and unit performance for each bucket surface roughness were generated. The total pressure distribution on bucket surface is used to show the free water sheet flow pattern on bucket surface. By comparing the variation of water sheet flow patterns on bucket surface with different roughness, this paper qualitatively analyses how the bucket surface roughness magnitude influences the impeding effect on free water sheet flow. Comparison of the torque variation of different bucket surface roughness highlighted the effect of the bucket surface roughness on the Pelton turbine output capacity. To further investigate the effect of bucket surface roughness on Pelton turbine performance, the relation between the relative efficiency loss rate and bucket surface roughness magnitude is quantitatively analysed. The result can be used to predict and evaluate the Pelton turbine performance.

Play as Self-Realization: Toward a General Theory of Play

Science.gov (United States)

Henricks, Thomas S.

2014-01-01

In a wide-ranging essay that reviews the major theories of plays and relates them to significant notions of the self, the author addresses the question of why we play. He does so to argue that play is a biologically driven project of self-understanding and self-realization, one that humans--although they also share the experience with other…

Effect of nanocrystalline surface of substrate on microstructure and ...

Indian Academy of Sciences (India)

surface layers or bulk nanocrystalline metals and alloys more effectively. ... severe plastic deformation on surface layers of bulk met- als at high strains and strain rates. .... scanning electron microscopy (SEM) (Zeiss, model: Sigma. VP), energy ...

Protective Surfacing for Playgrounds.

Science.gov (United States)

Frost, Joe L.

Noting that 90 percent of serious playground injuries result from falls to hard surfaces, this paper reviews the advantages and disadvantages of various playground surfacing materials in terms of cost, climate, durability, aesthetics, and play value. Findings are based on the personal experience of the author, government documents, laboratory…

Surface effects on converse piezoelectricity of crystals.

Science.gov (United States)

Molayem, Mohammad; Springborg, Michael; Kirtman, Bernard

2017-09-20

The contribution of surface units to bulk properties are often neglected in theoretical and computational studies of crystalline systems. We demonstrate that this assumption has to be made with caution in the case of (electric field) polarization. As a generalization of an earlier work on quasi-one-dimensional systems [Springborg, et al., Phys. Rev. B: Condens. Matter Mater. Phys., 2010, 82, 165442], it is shown that the polarization for 2D and 3D systems contains a surface contribution that can, in principle, take any value (within physical limits) and has consequences for converse piezoelectric responses. Subsequently, we determine the surface effects quantitatively for a group of ferroelectric perovskite structures. Our results indicate that such contributions can be substantial.

Effect of Superhydrophobic Surface of Titanium on Staphylococcus aureus Adhesion

Directory of Open Access Journals (Sweden)

Peifu Tang

2011-01-01

Full Text Available Despite the systemic antibiotics prophylaxis, orthopedic implants still remain highly susceptible to bacterial adhesion and resulting in device-associated infection. Surface modification is an effective way to decrease bacterial adhesion. In this study, we prepared surfaces with different wettability on titanium surface based on TiO2 nanotube to examine the effect of bacterial adhesion. Firstly, titanium plates were calcined to form hydrophilic TiO2 nanotube films of anatase phase. Subsequently, the nanotube films and inoxidized titaniums were treated with 1H, 1H, 2H, 2H-perfluorooctyl-triethoxysilane (PTES, forming superhydrophobic and hydrophobic surfaces. Observed by SEM and contact angle measurements, the different surfaces have different characteristics. Staphylococcus aureus (SA adhesion on different surfaces was evaluated. Our experiment results show that the superhydrophobic surface has contact angles of water greater than 150∘ and also shows high resistance to bacterial contamination. It is indicated that superhydrophobic surface may be a factor to reduce device-associated infection and could be used in clinical practice.

A pilot play-based intervention to improve the social play interactions of children with autism spectrum disorder and their typically developing playmates.

Science.gov (United States)

Henning, Belindi; Cordier, Reinie; Wilkes-Gillan, Sarah; Falkmer, Torbjorn

2016-08-01

Occupational therapists play a key role in addressing the social difficulties of children with ASD. However, interventions are often time intensive, without outcomes generalising beyond the clinic setting. To examine the feasibility and preliminary effectiveness of an intervention to address the social play skills of children with ASD. Participants in this multiple case study design were five children with autism spectrum disorder (ASD), five typically developing playmates and five parents of children with ASD. Two therapists and parents delivered the intervention involving clinic play sessions and home modules. Parents' treatment adherence was recorded. The Test of Playfulness was scored by a blinded rater to examine child outcomes following the intervention. Line graphs were used to examine case data. Percentage of non-overlapping data (PND) was used to calculate the single-case effect size for each child. Parents completed 92.2% of the intervention. Children's case data showed an upwards trend from pre- to post-intervention in four of the five pairs (child with ASD and playmate). However, there was a decrease in scores from post-intervention to the two-month home follow-up for all but one pair. PND indicated the intervention was effective for two children with ASD and three of their playmates, had a questionable effect on three children with ASD and no observable effect on two playmates. The intervention demonstrated preliminary feasibility and effectiveness for improving the social play skills of some children with ASD. Careful consideration is needed to identify which children with ASD and which playmates would be best suited for this intervention approach. © 2016 Occupational Therapy Australia.

Proximal and distal effects of play on child compliance with a brain-injured parent.

OpenAIRE

Ducharme, J M; Rushford, N

2001-01-01

Individuals with brain injury may experience severe cognitive and other impairments. For brain-injured parents, such deficits may be associated with child behavior problems, including noncompliance. We assessed the effects of a play period conducted by a brain-injured father on the compliance of his son, who had become uncooperative with his father after the injury. The child consistently demonstrated improved compliance during proximal and distal compliance sessions that followed father-son ...

The effects of sea surface temperature gradients on surface turbulent fluxes

Science.gov (United States)

Steffen, John

A positive correlation between sea surface temperature (SST) and wind stress perturbation near strong SST gradients (DeltaSST) has been observed in different parts of the world ocean, such as the Gulf Stream in the North Atlantic and the Kuroshio Extension east of Japan. These changes in winds and SSTs can modify near-surface stability, surface stress, and latent and sensible heat fluxes. In general, these small scale processes are poorly modeled in Numerical Weather Prediction (NWP) and climate models. Failure to account for these air--sea interactions produces inaccurate values of turbulent fluxes, and therefore a misrepresentation of the energy, moisture, and momentum budgets. Our goal is to determine the change in these surface turbulent fluxes due to overlooking the correlated variability in winds, SSTs, and related variables. To model these air--sea interactions, a flux model was forced with and without SST--induced changes to the surface wind fields. The SST modification to the wind fields is based on a baroclinic argument as implemented by the University of Washington Planetary Boundary-Layer (UWPBL) model. Other input parameters include 2-m air temperature, 2-m dew point temperature, surface pressure (all from ERA--interim), and Reynolds Daily Optimum Interpolation Sea Surface Temperature (OISST). Flux model runs are performed every 6 hours starting in December 2002 and ending in November 2003. From these model outputs, seasonal, monthly, and daily means of the difference between DeltaSST and no DeltaSST effects on sensible heat flux (SHF), latent heat flux (LHF), and surface stress are calculated. Since the greatest impacts occur during the winter season, six additional December-January-February (DJF) seasons were analyzed for 1987--1990 and 1999--2002. The greatest differences in surface turbulent fluxes are concentrated near strong SST fronts associated with the Gulf Stream and Kuroshio Extension. On average, 2002---2003 DJF seasonal differences in SHF

Role-Play and Student Engagement: Reflections from the Classroom

Science.gov (United States)

Stevens, Rachel

2015-01-01

Role-play is viewed by scholars as an effective active learning strategy: it encourages participation among passive learners, adds dynamism to the classroom and promotes the retention of material. But what do students think of role-play? This study surveyed 144 students after a role-play activity in a history course and asked them to identify what…

Are medical treatments for individuals and groups like single-play and multiple-play gambles?

Directory of Open Access Journals (Sweden)

Michael L. DeKay

2006-11-01

Full Text Available People are often more likely to accept risky monetary gambles with positive expected values when the gambles will be played more than once. We investigated whether this distinction between single-play and multiple-play gambles extends to medical treatments for individual patients and groups of patients. Resident physicians and medical students (extit{n} = 69 and undergraduates (extit{n} = 99 ranked 9 different flu shots and a no-flu-shot option in 1 of 4 combinations of perspective (individual patient vs. group of 1000 patients and uncertainty frame (probability vs. frequency. The rank of the no-flu-shot option (a measure of preference for treatment vs. no treatment was not significantly related to perspective or participant population. The main effect of uncertainty frame and the interaction between perspective and uncertainty frame approached significance (0.1 {extgreater} extit{p} {extgreater} 0.05, with the no-flu-shot option faring particularly poorly (treatment faring particularly well when decisions about many patients were based on frequency information. Undergraduate participants believed that the no-flu-shot option would be less attractive (treatment would be more attractive in decisions about many patients, but these intuitions were inconsistent with the actual ranks. These results and those of other studies suggest that medical treatments for individuals and groups are not analogous to single-play and multiple-play monetary gambles, perhaps because many people are unwilling to aggregate treatment outcomes over patients in the same way that they would compute net gains or losses over monetary gambles.

The influence of playing computer games on pupil's development

OpenAIRE

Pospíšilová, Lenka

2008-01-01

This thesis is about the effects of playing computer games on pupils and students behavior. It is divided into a theoretical and an investigative part. The theoretical part is dedicated to historical development of technologies and principals of game systems in relationship to technical progress. It adverts to psychological, social and biological effects of long time, intensive playing of games. It shows positive and negative effects ofthis activity. The work analyses typical pathological eve...

"If I Am Not Doing My Own Playing Then I Am Not Able to Truly Share the Gift of Play with Children": Using Poststructuralism and Care Ethics to Examine Future Early Childhood Educators' Relationships with Play in Adulthood

Science.gov (United States)

Nicholson, Julie; Shimpi, Priya Mariana; Rabin, Colette

2014-01-01

The current sociopolitical context of schooling is positioning play as incongruous with children's academic learning. As a result, teacher educators must increasingly guide future early childhood professionals to develop the skills and knowledge necessary to become effective play advocates. This includes articulating the value of play across the…

Surface for dummies

CERN Document Server

Rathbone, Andy

2014-01-01

Make Microsoft's Surface work-and play-just the way you want it to Microsoft's Surface tablet has the features and personality you're looking for, with a robust environment for business computing that doesn't skimp on fun. Surface for Dummies, 2nd Edition explains how Windows 8.1 Pro and Windows RT differ, and helps you decide which Surface model is best for you. Step by step, this book walks you through both the hardware and software features of the Surface, including the touch cover and type cover, Windows RT and Windows 8.1 Pro operating systems, and the coveted Office Home & Student 2013 s

FORMATION OF ANTIBACTERIAL EFFECT ON CERAMIC TILE SURFACES

Directory of Open Access Journals (Sweden)

Selçuk ÖZCAN

2017-03-01

Full Text Available Biocidal antimicrobial molecular barrier (BAMB solutions are known to provide antimicrobial effect on the surfaces in industrial applications. However, there has been a lack of scientific reports about the subject in the literature. In this study, in order to impart an antimicrobial surface property on ceramic surfaces, a BAMB solution was applied on gloss fired ceramic wall tile substrates and the surface antimicrobial activity results were compared with that of plain wall tiles (without BAMB application. The ceramic surfaces were cleaned, and stove dried at120°C prior to spray coating with a BAMB solution. The coated substrates were dried in the ambient. The intactness of the coatings was checked with the bromophenol blue test. The microstructural and molecular characterization of the BAMB coated surfaces were carried out with SEM imaging and surface FTIR, respectively. The antimicrobial activity tests of the surfaces were conducted according to ASTM E2180-07 (Standard Test Method for Determining the Activity of Incorporated Antimicrobial Agent in Polymeric or Hydrophobic Materials. The microorganisms used were Staphylococcus aureus (ATCC 6538 and Pseudomonas aeruginosa (ATCC 15442 bacteria. The BAMB coated surfaces showed less flocculent bacterial growth in comparison to uncoated ceramic surfaces leading to the conclusion that the BAMB improved the antimicrobial property.

Games people play the psychology of human relationships

CERN Document Server

Berne, Eric

2010-01-01

The bestselling Games People Play is the book that has helped millions of people understand the dynamics of relationships, by psychiatrist Eric Berne.We all play games. In every encounter with other people we are doing so. The nature of these games depends both on the situation and on who we meet.Eric Berne's classic Games People Play is the most accessible and insightful book ever written about the games we play: those patterns of behaviour that reveal hidden feelings and emotions. Wise and witty, it shows the underlying motivations behind our relationships and explores the roles that we try to play - and are forced to play.Games People Play gives you the keys to unlock the psychology of others - and yourself. You'll become more honest, more effective, and a true team player.'A brilliant, amusing, and clear catalogue of the psychological theatricals that human beings play over and over again' Kurt VonnegutEric Berne was a prominent psychiatrist and bestselling author.After inventing his groundbreaking Transa...

Play and play occupation: a survey of paediatric occupational therapy practice in Ireland

Directory of Open Access Journals (Sweden)

Alice Moore

2017-04-01

Full Text Available Purpose - Play occupation has been identified as an essential part of children’s lives, and it subsequently features in paediatric occupational therapy. However, few studies address the current place of play and play occupation in occupational therapy practice. This study aims to address this gap in knowledge by exploring paediatric occupational therapists’ perspectives on the place of play and play occupation in occupational therapy practice in Ireland. Design/methodology/approach - A cross-sectional online survey was conducted to gather data about the current use of play in the occupational therapy for children under 12 years. Convenience sampling and snowball recruitment techniques were used to recruit paediatric occupational therapists. Data were analysed using descriptive statistics and qualitative content analysis. Findings - In total, 65 therapists responded to the survey (estimated response rate, 32%. Results are organised into four sections: demographics and practice context, play assessment practices, use of play in practice and perceived barriers to play-centred practice. Respondents reported that they valued play as a childhood occupation. However, the survey findings identified that the primary focus was on play as a means to an end. Lack of education on play (research, theory and interventions and pressures in the workplace have been identified as barriers to play-centred practice. Research limitations/implications - Findings indicate that there is a mismatch between therapists valuing play as an occupation and how play is used in occupational therapy practice. Unless clarifications are made about play occupation as being different to skills acquisition in childhood, play occupation will continue to get overlooked as an authentic concern of occupation-centred practice. Thus, play as occupation deserves further attention from educators, researchers and practitioners as a means of strengthening occupation-centred practice, in

Effective Boundary Slip Induced by Surface Roughness and Their Coupled Effect on Convective Heat Transfer of Liquid Flow

Directory of Open Access Journals (Sweden)

Yunlu Pan

2018-05-01

Full Text Available As a significant interfacial property for micro/nano fluidic system, the effective boundary slip can be induced by the surface roughness. However, the effect of surface roughness on the effective slip is still not clear, both increased and decreased effective boundary slip were found with increased roughness. The present work develops a simplified model to study the effect of surface roughness on the effective boundary slip. In the created rough models, the reference position of the rough surfaces to determinate effective boundary slip was set based on ISO/ASME standard and the surface roughness parameters including Ra (arithmetical mean deviation of the assessed profile, Rsm (mean width of the assessed profile elements and shape of the texture varied to form different surface roughness. Then, the effective boundary slip of fluid flow through the rough surface was analyzed by using COMSOL 5.3. The results show that the effective boundary slip induced by surface roughness of fully wetted rough surface keeps negative and further decreases with increasing Ra or decreasing Rsm. Different shape of roughness texture also results in different effective slip. A simplified corrected method for the measured effective boundary slip was developed and proved to be efficient when the Rsm is no larger than 200 nm. Another important finding in the present work is that the convective heat transfer firstly increases followed by an unobvious change with increasing Ra, while the effective boundary slip keeps decreasing. It is believed that the increasing Ra enlarges the area of solid-liquid interface for convective heat transfer, however, when Ra is large enough, the decreasing roughness-induced effective boundary slip counteracts the enhancement effect of roughness itself on the convective heat transfer.

Effects of surface atomistic modification on mechanical properties of gold nanowires

International Nuclear Information System (INIS)

Sun, Xiao-Yu; Xu, Yuanjie; Wang, Gang-Feng; Gu, Yuantong; Feng, Xi-Qiao

2015-01-01

Highlights: • Molecular dynamics simulations of surface modification effect of Au nanowires. • Surface modification can greatly affect the mechanical properties of nanowires. • Core–shell model is used to elucidate the effect of residual surface stress. - Abstract: Modulation of the physical and mechanical properties of nanowires is a challenging issue for their technological applications. In this paper, we investigate the effects of surface modification on the mechanical properties of gold nanowires by performing molecular dynamics simulations. It is found that by modifying a small density of silver atoms to the surface of a gold nanowire, the residual surface stress state can be altered, rendering a great improvement of its plastic yield strength. This finding is in good agreement with experimental measurements. The underlying physical mechanisms are analyzed by a core–shell nanowire model. The results are helpful for the design and optimization of advanced nanomaterial with superior mechanical properties

Thermal inertia and surface heterogeneity on Mars

Science.gov (United States)

Putzig, Nathaniel E.

Thermal inertia derived from temperature observations is critical for understanding surface geology and assessing potential landing sites on Mars. Derivation methods generally assume uniform surface properties for any given observation. Consequently, horizontal heterogeneity and near-surface layering may yield apparent thermal inertia that varies with time of day and season. To evaluate the effects of horizontal heterogeneity, I modeled the thermal behavior of surfaces containing idealized material mixtures (dust, sand, duricrust, and rocks) and differing slope facets. These surfaces exhibit diurnal and seasonal variability in apparent thermal inertia of several 100 tiu, 1 even for components with moderately contrasting thermal properties. To isolate surface effects on the derived thermal inertia of Mars, I mapped inter- annual and seasonal changes in albedo and atmospheric dust opacity, accounting for their effects in a modified derivation algorithm. Global analysis of three Mars years of MGS-TES 2 data reveals diurnal and seasonal variations of ~200 tiu in the mid-latitudes and 600 tiu or greater in the polar regions. Correlation of TES results and modeled apparent thermal inertia of heterogeneous surfaces indicates pervasive surface heterogeneity on Mars. At TES resolution, the near-surface thermal response is broadly dominated by layering and is consistent with the presence of duricrusts over fines in the mid-latitudes and dry soils over ground ice in the polar regions. Horizontal surface mixtures also play a role and may dominate at higher resolution. In general, thermal inertia obtained from single observations or annually averaged maps may misrepresent surface properties. In lieu of a robust heterogeneous- surface derivation technique, repeat coverage can be used together with forward-modeling results to constrain the near-surface heterogeneity of Mars. 1 tiu == J m -2 K -1 s - 2 Mars Global Surveyor Thermal Emission Spectrometer

Electrochemical Approach for Effective Antifouling and Antimicrobial Surfaces.

Science.gov (United States)

Gaw, Sheng Long; Sarkar, Sujoy; Nir, Sivan; Schnell, Yafit; Mandler, Daniel; Xu, Zhichuan J; Lee, Pooi See; Reches, Meital

2017-08-09

Biofouling, the adsorption of organisms to a surface, is a major problem today in many areas of our lives. This includes: (i) health, as biofouling on medical device leads to hospital-acquired infections, (ii) water, since the accumulation of organisms on membranes and pipes in desalination systems harms the function of the system, and (iii) energy, due to the heavy load of the organic layer that accumulates on marine vessels and causes a larger consumption of fuel. This paper presents an effective electrochemical approach for generating antifouling and antimicrobial surfaces. Distinct from previously reported antifouling or antimicrobial electrochemical studies, we demonstrate the formation of a hydrogen gas bubble layer through the application of a low-voltage square-waveform pulses to the conductive surface. This electrochemically generated gas bubble layer serves as a separation barrier between the surroundings and the target surface where the adhesion of bacteria can be deterred. Our results indicate that this barrier could effectively reduce the adsorption of bacteria to the surface by 99.5%. We propose that the antimicrobial mechanism correlates with the fundamental of hydrogen evolution reaction (HER). HER leads to an arid environment that does not allow the existence of live bacteria. In addition, we show that this drought condition kills the preadhered bacteria on the surface due to water stress. This work serves as the basis for the exploration of future self-sustainable antifouling techniques such as incorporating it with photocatalytic and photoelectrochemical reactions.

Causes and Effects of Online Video Game Playing Among Junior-Senior High School Students in Malang East Java

OpenAIRE

Eskasasnanda, I Dewa Putu

2017-01-01

Science and technology development causes a lot of changes in any fields including the form of popular games among the Junior and Senior High School students in Indonesia. The traditional games that are famous formerly have been replaced by the modern games like online video game. This article discusses the cause and effect of the online video game playing on the Junior and Senior High Schools students in Malang. This study reveal that students play video games online due to peers pressure; a...

Advances in surface treatments: Technology, applications, effects

International Nuclear Information System (INIS)

Niku-Lari, A.

1987-01-01

An international handbook has been produced to include all aspects of residual stresses, including the theoretical background, effects of residual stresses, measurement and calculation and quantitative assessment of residual stress effects. Techniques for altering residual stresses, particularly surface treatments, are discussed. Up to date information on the state of the art is presented. (UK)

Repair Bond Strength of Aged Resin Composite after Different Surface and Bonding Treatments

Directory of Open Access Journals (Sweden)

Michael Wendler

2016-07-01

Full Text Available The aim of this study was to compare the effect of different mechanical surface treatments and chemical bonding protocols on the tensile bond strength (TBS of aged composite. Bar specimens were produced using a nanohybrid resin composite and aged in distilled water for 30 days. Different surface treatments (diamond bur, phosphoric acid, silane, and sandblasting with Al2O3 or CoJet Sand, as well as bonding protocols (Primer/Adhesive were used prior to application of the repair composite. TBS of the specimens was measured and the results were analyzed using analysis of variance (ANOVA and the Student–Newman–Keuls test (α = 0.05. Mechanically treated surfaces were characterized under SEM and by profilometry. The effect of water aging on the degree of conversion was measured by means of FTIR-ATR spectroscopy. An important increase in the degree of conversion was observed after aging. No significant differences in TBS were observed among the mechanical surface treatments, despite variations in surface roughness profiles. Phosphoric acid etching significantly improved repair bond strength values. The cohesive TBS of the material was only reached using resin bonding agents. Application of an intermediate bonding system plays a key role in achieving reliable repair bond strengths, whereas the kind of mechanical surface treatment appears to play a secondary role.

Role-playing is an effective instructional strategy for genetic counseling training: an investigation and comparative study.

Science.gov (United States)

Xu, Xiao-Feng; Wang, Yan; Wang, Yan-Yan; Song, Ming; Xiao, Wen-Gang; Bai, Yun

2016-09-02

Genetic diseases represent a significant public health challenge in China that will need to be addressed by a correspondingly large number of professional genetic counselors. However, neither an official training program for genetic counseling, nor formal board certification, was available in China before 2015. In 2009, a genetic counseling training program based on role-playing was implemented as a pilot study at the Third Military Medical University to train third-year medical students. Questionnaires on participant attitudes to the program and role-playing were randomly administered to 324 students after they had finished their training. Pre- and post-training instructional tests, focusing on 42 key components of genetic counseling, were administered randomly to 200 participants to assess mastery of each component. Finally, scores in final examinations of 578 participants from 2009 to 2011 were compared to scores obtained by 614 non-participating students from 2006 to 2008 to further assess program efficacy. Both the training program and the instructional strategy of role-playing were accepted by most participants. Students believed that role-playing improved their practice of genetic counseling and medical genetics, enhanced their communication skills, and would likely contribute to future professional performance. The average understanding of 40 of the key points in genetic counseling was significantly improved, and most students approached excellent levels of mastery. Scores in final examinations and the percentages of students scoring above 90 were also significantly elevated. Role-playing is a feasible and effective instructional strategy for training genetic counselors in China as well as in other developing countries.

The Surface Layer Homology Domain-Containing Proteins of Alkaliphilic Bacillus pseudofirmus OF4 Play an Important Role in Alkaline Adaptation via Peptidoglycan Synthesis.

Science.gov (United States)

Fujinami, Shun; Ito, Masahiro

2018-01-01

It is well known that the Na + cycle and the cell wall are essential for alkaline adaptation of Na + -dependent alkaliphilic Bacillus species. In Bacillus pseudofirmus OF4, surface layer protein A (SlpA), the most abundant protein in the surface layer (S-layer) of the cell wall, is involved in alkaline adaptation, especially under low Na + concentrations. The presence of a large number of genes that encode S-layer homology (SLH) domain-containing proteins has been suggested from the genome sequence of B. pseudofirmus OF4. However, other than SlpA, the functions of SLH domain-containing proteins are not well known. Therefore, a deletion mutant of the csaB gene, required for the retention of SLH domain-containing proteins on the cell wall, was constructed to investigate its physiological properties. The csaB mutant strain of B. pseudofirmus OF4 had a chained morphology and alkaline sensitivity even under a 230 mM Na + concentration at which there is no growth difference between the parental strain and the slpA mutant strain. Ultra-thin section transmission electron microscopy showed that a csaB mutant strain lacked an S-layer part, and its peptidoglycan (PG) layer was disturbed. The slpA mutant strain also lacked an S-layer part, although its PG layer was not disturbed. These results suggested that the surface layer homology domain-containing proteins of B. pseudofirmus OF4 play an important role in alkaline adaptation via peptidoglycan synthesis.

Screening effect on the polaron by surface plasmons

Science.gov (United States)

Xu, Xiaoying; Xu, Xiaoshan; Seal, Katyayani; Guo, Hangwen; Shen, Jian; Low Dimensional Materials Physics, Oak Ridge National Lab Team; University of Tennessee Team; Physics Department, Fudan University Team

2011-03-01

Surface plasmons occur when the conduction electrons at a metal/dielectric interface resonantly interact with external electromagnetic fields. While surface plasmons in vicinity of a polaron in the dielectric material, a strong screening effect on polaron characteristics is introduced. In this work, we observed the reduction of polarons in multiferroic LuFe2O4, which is mainly contributed by surface plasmons. Research sponsored 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.

The play grid

DEFF Research Database (Denmark)

Fogh, Rune; Johansen, Asger

2013-01-01

In this paper we propose The Play Grid, a model for systemizing different play types. The approach is psychological by nature and the actual Play Grid is based, therefore, on two pairs of fundamental and widely acknowledged distinguishing characteristics of the ego, namely: extraversion vs. intro...

The Effect of Parental Involvement and Encouragement on Preschool Children's Symbolic Play

Science.gov (United States)

Marjanovic-Umek, Ljubica; Fekonja-Peklaj, Urška; Podlesek, Anja

2014-01-01

The purpose of our study was to examine the ways in which parents engage in play with their children within the family context and to establish which parental play behaviour predicts the play behaviour of their children during interactive play with toys. The sample included 58 children from 2;6 to 6 years old and their parents. The parent-child…

Deep-Water Resedimented Carbonate Exploration Play Types: Controls and Models

Science.gov (United States)

Minzoni, M.; Janson, X.; Kerans, C.; Playton, T.; Winefield, P.; Burgess, P. M.

2016-12-01

Deepwater resedimented deposits have been described in both modern and ancient carbonate sequences, many with good reservoir potential, for example the giant Cretaceous Poza Rica field in Mexico ( 40 MMBoe), the Mississippian Tangiz field in Kazakhstan, and several fields in the U.S. Permian basin (several Tcf gas). Nevertheless, carbonate slope and basin systems remain poorly understood when compared to their siliciclastic counterparts. Legacy published and unpublished work, combined with a global database of surface and sub-surface examples of resedimented carbonates, has highlighted that downslope resedimentation of carbonate material is in large part controlled by the evolution of the parent platform margin, which in turn is best characterized in terms of various controlling processes such as the carbonate factory type, tectonic setting, eustatic variations, and prevailing wind direction and ocean current patterns. Two generic play types emerge: (i) attached carbonate slope play -developed immediately adjacent to the parent carbonate platform and dominated by rock fall and platform collapse deposits or in situ boundstone; and (ii) detached carbonate slope play - deposited further from the platform margin via channelized turbidity currents and other mass-flow processes. High-rising, steep, bypass platform margins with collapse scars and grain-dominated factories have the highest potential to generate channelized and detached deep-water reservoirs with high initial porosity and permeability. Best reservoirs are aragonitic grainstones transported from the platform into the adjacent basin, and undergoing dissolution in submarine undersaturated water with early formation of secondary porosity to further enhance reservoir properties. Any exploration model aiming at identifying potential resedimented carbonate plays should be based on carbonate platform configurations and factory types favorable for re-sedimentation of large sedimentary bodies and preservation or

Effect of surface hydroxyl groups on heat capacity of mesoporous silica

Science.gov (United States)

Marszewski, Michal; Butts, Danielle; Lan, Esther; Yan, Yan; King, Sophia C.; McNeil, Patricia E.; Galy, Tiphaine; Dunn, Bruce; Tolbert, Sarah H.; Hu, Yongjie; Pilon, Laurent

2018-05-01

This paper quantifies the effect of surface hydroxyl groups on the effective specific and volumetric heat capacities of mesoporous silica. To achieve a wide range of structural diversity, mesoporous silica samples were synthesized by various methods, including (i) polymer-templated nanoparticle-based powders, (ii) polymer-templated sol-gel powders, and (iii) ambigel silica samples dried by solvent exchange at room temperature. Their effective specific heat capacity, specific surface area, and porosity were measured using differential scanning calorimetry and low-temperature nitrogen adsorption-desorption measurements. The experimentally measured specific heat capacity was larger than the conventional weight-fraction-weighted specific heat capacity of the air and silica constituents. The difference was attributed to the presence of OH groups in the large internal surface area. A thermodynamic model was developed based on surface energy considerations to account for the effect of surface OH groups on the specific and volumetric heat capacity. The model predictions fell within the experimental uncertainty.

Conformation evolution of oil contaminants onto aluminum oxide surface in aqueous solution: The effect of surface coverage

Energy Technology Data Exchange (ETDEWEB)

Xie, Wenkun; Liu, Haitao, E-mail: xwk584523412@126.com; Sun, Yazhou; Fu, Hongya; Liang, Yingchun

2017-01-15

Highlights: • The dynamic conformational change of oil contaminations, at various surface coverages onto perfect α-Al{sub 2}O{sub 3}(0001) surface in aqueous solution is given. • The effect of surface coverage of oil molecules on the driving forces for the conformational change of oil contaminations is described. • The effect of interfacial water on the conformational change and even detachment of oil contaminations is considered. - Abstract: The microscopic conformational change process of oil contaminants adhered onto perfect α-Al{sub 2}O{sub 3} (0001) surface in aqueous solution was investigated by using all-atom classic molecular dynamics simulations. The change in removal mechanism of oil contaminants induced by surface coverage (surface area per molecule) was emphatically explored. Our simulation results strongly reveal that the increase in oil surface coverage induces an evident difference in microscopic detachment processes of oil contaminants. At a low surface coverage, oil contaminants can be thoroughly detached from solid surface. The whole detachment process could be divided into multi stages, including conformational change of oil contaminants on solid surface, dynamic motion of those in bulk solution and rapid migration of those from bulk solution to air/water interface. With surface coverage increasing, water diffusion becomes the key to induce conformational change and promote the detachment of oil contaminants. When oil surface coverage exceeds a threshold value, oil contaminants also undertake an evident conformational change process exhibiting typical characteristics but an incomplete detachment process occurs. All findings of the present study are helpful for the interpretation of the removal mechanism of oil contaminants on solid surface.

The surface effect on axisymmetric wave propagation in piezoelectric cylindrical shells

Directory of Open Access Journals (Sweden)

Yunying Zhou

2015-02-01

Full Text Available Based on the surface piezoelectricity theory and first-order shear deformation theory, the surface effect on the axisymmetric wave propagating in piezoelectric cylindrical shells is analyzed. The Gurtin–Murdoch theory is utilized to get the nontraditional boundary conditions and constitutive equations of the surface, in company with classical governing equations of the bulk, from which the basic formulations are obtained. Numerical results show that the surface layer has a profound effect on wave characteristics in nanostructure at a higher mode.

Role-Playing in Science Education: An Effective Strategy for Developing Multiple Perspectives

Science.gov (United States)

Howes, Elaine V.; Cruz, Barbara C.

2009-01-01

Role-playing can be an engaging and creative strategy to use in the college classroom. Using official accounts, personal narratives, and diaries to recreate a particular time period, event, or personality, the instructional strategy alternately referred to as role-playing, dramatic improvisation, or first-person characterization can be an…

Size- and shape-dependent surface thermodynamic properties of nanocrystals

Science.gov (United States)

Fu, Qingshan; Xue, Yongqiang; Cui, Zixiang

2018-05-01

As the fundamental properties, the surface thermodynamic properties of nanocrystals play a key role in the physical and chemical changes. However, it remains ambiguous about the quantitative influence regularities of size and shape on the surface thermodynamic properties of nanocrystals. Thus by introducing interface variables into the Gibbs energy and combining Young-Laplace equation, relations between the surface thermodynamic properties (surface Gibbs energy, surface enthalpy, surface entropy, surface energy and surface heat capacity), respectively, and size of nanocrystals with different shapes were derived. Theoretical estimations of the orders of the surface thermodynamic properties of nanocrystals agree with available experimental values. Calculated results of the surface thermodynamic properties of Au, Bi and Al nanocrystals suggest that when r > 10 nm, the surface thermodynamic properties linearly vary with the reciprocal of particle size, and when r < 10 nm, the effect of particle size on the surface thermodynamic properties becomes greater and deviates from linear variation. For nanocrystals with identical equivalent diameter, the more the shape deviates from sphere, the larger the surface thermodynamic properties (absolute value) are.

Alibis for Adult Play

Science.gov (United States)

2017-01-01

The social meanings of play sit at odds with norms of responsible and productive adult conduct. To be “caught” playing as an adult therefore risks embarrassment. Still, many designers want to create enjoyable, nonembarrassing play experiences for adults. To address this need, this article reads instances of spontaneous adult play through the lens of Erving Goffman’s theory of the interaction order to unpack conditions and strategies for nonembarrassing adult play. It identifies established frames, segregated audiences, scripts supporting smooth performance, managing audience awareness, role distancing, and, particularly, alibis for play: Adults routinely provide alternative, adult-appropriate motives to account for their play, such as child care, professional duties, creative expression, or health. Once legitimized, the norms and rules of play themselves then provide an alibi for behavior that would risk being embarrassing outside play.

Laser-induced novel patterns: As smart strain actuators for new-age dental implant surfaces

Energy Technology Data Exchange (ETDEWEB)

Celen, Serap, E-mail: serap.celen@ege.edu.tr [Ege University, Faculty of Engineering, Mechanical Engineering Department, Izmir, 35100 (Turkey); Oezden, Hueseyin [Ege University, Faculty of Engineering, Mechanical Engineering Department, Izmir, 35100 (Turkey)

2012-12-15

Highlights: Black-Right-Pointing-Pointer It is time for that paradigm shift and for an exploration of novel surfaces. Black-Right-Pointing-Pointer We developed novel 3D smart surfaces as strain actuators by nanosecond laser pulse energies. Black-Right-Pointing-Pointer We analyzed these smart surface morphologies using FEM. Black-Right-Pointing-Pointer We estimated their internal stiffness values which play a great role on stress shielding effect. Black-Right-Pointing-Pointer We gave the optimum operation parameters. - Abstract: Surface morphologies of titanium implants are of crucial importance for long-term mechanical adaptation for following implantation. One major problem is the stress shielding effect which originates from the mismatch of the bone and the implant elasticity. It is time for a paradigm shift and for an exploration of novel smart surfaces to prevent this problem. Several surface treatment methods have traditionally been used to modify the surface morphology of titanium dental implants. The laser micro-machining can be considered as a unique and promising, non-contact, no media, contamination free, and flexible treatment method for modifying surface properties of materials in the biomedical industry. The aim of the present study is two folds; to develop novel 3D smart surfaces which can be acted as strain actuators by nanosecond laser pulse energies and irradiation strategies. And analyze these smart surface morphologies using finite element methods in order to estimate their internal stiffness values which play a great role on stress shielding effect. Novel 3D smart strain actuators were prepared using an ytterbium fiber laser ({lambda} = 1060 nm) with 200-250 ns pulse durations on commercial pure titanium dental implant material specimen surfaces and optimum operation parameters were suggested.

Presence of the relative age effect and its effect on playing time among under-20 players in the Norwegian premier league Tippeligaen – a four-year follow up

Directory of Open Access Journals (Sweden)

Stig Arve Sæther

2016-03-01

Full Text Available European top-level soccer clubs are continually looking for talented players. Few clubs, however, are willing to let youth players play at the highest senior level. Perhaps as a consequence, the search for talented players has resulted in an imbalance in the characteristics of these players, towards an overrepresentation of players born early in the selection year, an effect called the relative age effect (RAE. The RAE has been documented to be present among senior top-level players. Even so, few studies have investigated the effect among youth players at the senior level. The aim of this study is to examine RAE among U17-U20 players in the Norwegian premier league Tippeligaen in the 2009-2012 seasons. Participants were 315 male players born in 1990-1996. The results showed that 68% of the players were born in the two first quartiles of the year. The effect was even increasing in the four-year period. As we could expect based on the literature, the oldest players are given more playing time. However, the connection between playing time and RAE was inconsistent. Norwegian top-level soccer seems to be affected by the RAE when selecting their players. These players are not however guaranteed playing time because of the RAE.

Effect of Electropulsing-Assisted Ultrasonic Nanocrystalline Surface Modification on the Surface Mechanical Properties and Microstructure of Ti-6Al-4V Alloy

Science.gov (United States)

Ye, Yongda; Wang, Haibo; Tang, Guoyi; Song, Guolin

2018-05-01

The effect of electropulsing-assisted ultrasonic nanocrystalline surface modification (EP-UNSM) on surface mechanical properties and microstructure of Ti-6Al-4V alloy is investigated. Compared to conventional ultrasonic nanocrystalline surface modification (UNSM), EP-UNSM can effectively facilitate surface roughness and morphology, leading to excellent surface roughness (reduced from Ra 0.918 to Ra 0.028 μm by UNSM and Ra 0.019 μm by EP-UNSM) and smoother morphology with less cracks and defects. Surface friction coefficients are enhanced, resulting in lower and smoother friction coefficients. In addition, the surface-strengthened layer and ultra-refined grains are significantly enhanced with more severe plastic deformation and a greater surface hardness (a maximum hardness value of 407 HV and an effective depth of 550 μm, in comparison with the maximum hardness value of 364 HV and effective depth of 300 μm obtained by conventional UNSM). Remarkable enhancement of surface mechanical properties can be attributed to the refined gradient microstructure and the enhanced severe plastic deformation layer induced by coupling the effects of UNSM and electropulsing. The accelerated dislocation mobility and atom diffusion caused by the thermal and athermal effects of electropulsing treatment may be the primary intrinsic reasons for these improvements.

An evaluation of the effect of surface chromium concentration on the oxidation of a stainless steel

International Nuclear Information System (INIS)

Lobb, R.C.; Evans, H.E.

1983-01-01

Short-term oxidation tests have been performed at 850 deg C in a CO 2 -based atmosphere on 20Cr-25Ni-Nb-stabilized steels previously exposed to dynamic vacuum at 1000 deg C. This pre-treatment preferentially removes chromium from the metal surface and is always detrimental to the oxidation properties. It is shown that porous, iron-rich oxides initially form on specimens with surface chromium concentrations 18.5 w/o chromium, a protective surface layer is produced. It is suggested that the transition between these extremes is determined by nucleation conditions and, in the present steels, it is shown how the metal grain size plays a significant role. (author)

Superhydrophobic nanostructured Kapton® surfaces fabricated through Ar + O2 plasma treatment: Effects of different environments on wetting behaviour

Science.gov (United States)

Barshilia, Harish C.; Ananth, A.; Gupta, Nitant; Anandan, C.

2013-03-01

Kapton® [poly (4,4'-oxy diphenylene pyromellitimide)] polyimides have widespread usage in semiconductor devices, solar arrays, protective coatings and space applications, due to their excellent chemical and physical properties. In addition to their inherent properties, imparting superhydrophobicity on these surfaces will be an added advantage. Present work describes the usage of Ar + O2 plasma treatment for the preparation of superhydrophobic Kapton® surfaces. Immediately after the plasma treatment, the surfaces showed superhydrophilicity as a result of high energy dangling bonds and polar group concentration. But the samples kept in low vacuum for 48 h exhibited superhydrophobicity with high water contact angles (>150°). It is found that the post plasma treatment process, called ageing, especially in low vacuum plays an important role in delivering superhydrophobic property to Kapton®. Field emission scanning electron microscopy and atomic force microscopy were used to probe the physical changes in the surface of the Kapton®. The surfaces showed formation of nano-feathers and nano-tussock microstructures with variation in surface roughness against plasma treatment time. A thorough chemical investigation was performed using Fourier transform infrared spectroscopy and micro-Raman spectroscopy, which revealed changes in the surface of the Ar + O2 plasma treated Kapton®. Surface chemical species of Kapton® were confirmed again by X-ray photoelectron spectroscopy spectra for untreated surfaces whereas Ar + O2 plasma treated samples showed the de-bonding and re-organization of structural elements. Creation of surface roughness plays a dominant role in the contribution of superhydrophobicity to Kapton® apart from the surface modifications due to Ar + O2 plasma treatment and ageing in low vacuum.

Alibis for Adult Play: A Goffmanian Account of Escaping Embarrassment in Adult Play.

Science.gov (United States)

Deterding, Sebastian

2018-05-01

The social meanings of play sit at odds with norms of responsible and productive adult conduct. To be "caught" playing as an adult therefore risks embarrassment. Still, many designers want to create enjoyable, nonembarrassing play experiences for adults. To address this need, this article reads instances of spontaneous adult play through the lens of Erving Goffman's theory of the interaction order to unpack conditions and strategies for nonembarrassing adult play. It identifies established frames, segregated audiences, scripts supporting smooth performance, managing audience awareness, role distancing, and, particularly, alibis for play: Adults routinely provide alternative, adult-appropriate motives to account for their play, such as child care, professional duties, creative expression, or health. Once legitimized, the norms and rules of play themselves then provide an alibi for behavior that would risk being embarrassing outside play.

A methodology for modeling surface effects on stiff and soft solids

Science.gov (United States)

He, Jin; Park, Harold S.

2018-06-01

We present a computational method that can be applied to capture surface stress and surface tension-driven effects in both stiff, crystalline nanostructures, like size-dependent mechanical properties, and soft solids, like elastocapillary effects. We show that the method is equivalent to the classical Young-Laplace model. The method is based on converting surface tension and surface elasticity on a zero-thickness surface to an initial stress and corresponding elastic properties on a finite thickness shell, where the consideration of geometric nonlinearity enables capturing the out-of-plane component of the surface tension that results for curved surfaces through evaluation of the surface stress in the deformed configuration. In doing so, we are able to use commercially available finite element technology, and thus do not require consideration and implementation of the classical Young-Laplace equation. Several examples are presented to demonstrate the capability of the methodology for modeling surface stress in both soft solids and crystalline nanostructures.

Effect of surface roughness and surface modification of indium tin oxide electrode on its potential response to tryptophan

International Nuclear Information System (INIS)

Khan, Md. Zaved Hossain; Nakanishi, Takuya; Kuroiwa, Shigeki; Hoshi, Yoichi; Osaka, Tetsuya

2011-01-01

Highlights: → We examine factors affecting potential response of ITO electrode to tryptophan. → Surface roughness of ITO electrode affects the stability of its rest potential. → Surface modification is effective for ITO electrode with a certain roughness. → Optimum values of work function exist for potential response of ITO to tryptophan. - Abstract: The effect of surface modification of indium tin oxide (ITO) electrode on its potential response to tryptophan was investigated for ITO substrates with different surface roughness. It was found that a small difference in surface roughness, between ∼1 and ∼2 nm of R a evaluated by atomic force microscopy, affects the rest potential of ITO electrode in the electrolyte. A slight difference in In:Sn ratio at the near surface of the ITO substrates, measured by angle-resolved X-ray photoelectron spectrometry and Auger electron spectroscopy is remarkable, and considered to relate with surface roughness. Interestingly, successive modification of the ITO surface with aminopropylsilane and disuccinimidyl suberate, of which essentiality to the potential response to indole compounds we previously reported, improved the stability of the rest potential and enabled the electrodes to respond to tryptophan in case of specimens with R a values ranging between ∼2 and ∼3 nm but not for those with R a of ∼1 nm. It was suggested that there are optimum values of effective work function of ITO for specific potential response to tryptophan, which can be obtained by the successive modification of ITO surface.

Diffuse Surface Scattering in the Plasmonic Resonances of Ultralow Electron Density Nanospheres.

Science.gov (United States)

Monreal, R Carmina; Antosiewicz, Tomasz J; Apell, S Peter

2015-05-21

Localized surface plasmon resonances (LSPRs) have recently been identified in extremely diluted electron systems obtained by doping semiconductor quantum dots. Here, we investigate the role that different surface effects, namely, electronic spill-out and diffuse surface scattering, play in the optical properties of these ultralow electron density nanosystems. Diffuse scattering originates from imperfections or roughness at a microscopic scale on the surface. Using an electromagnetic theory that describes this mechanism in conjunction with a dielectric function including the quantum size effect, we find that the LSPRs show an oscillatory behavior in both position and width for large particles and a strong blue shift in energy and an increased width for smaller radii, consistent with recent experimental results for photodoped ZnO nanocrystals. We thus show that the commonly ignored process of diffuse surface scattering is a more important mechanism affecting the plasmonic properties of ultralow electron density nanoparticles than the spill-out effect.

Systematic observation of play behavior in autistic children.

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Black, M; Freeman, B J; Montgomery, J

1975-12-01

The play behavior, defined as interaction with peers and objects, of five autistic children was systematically observed in four environments, i.e., a stark environment, a theraplay unit, a playroom, and an outside play deck. The preliminary results suggested that (1) with some children environment has little or no effect on their play behavior; (2) with multiple objects, autistic children frequently related to the objects rather than to their peers; (3) object play was most frequently at the manipulative stage and often included repetitive and negative behavior; (4) within a confined space with no objects present, autistic children frequently engaged in solitary repetitive behavior; and (5) within a confined space designed to facilitate a movement flow (theraplay), autistic children modeled and imitated and were involved in gross motor play together.

Playing Shakespeare.

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Bashian, Kathleen Ryniker

1993-01-01

Describes a yearlong project at 12 Catholic middle schools in the Diocese of Arlington, Virginia, to incorporate the plays of William Shakespeare into the curriculum. Teachers attended university lectures and directed students in performances of the plays. Concludes that Shakespeare can be understood and enjoyed by middle school students. (BCY)

Virtual Playgrounds? Assessing the Playfulness of Massively Multiplayer Online Role-Playing Games

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Graham, Kerrie Lewis

2010-01-01

Millions of children and adults devote much of their leisure time to playing massively multiplayer online role-playing games (MMORPGs). Most observers commonly categorize computer games as a play activity, but this article asks whether MMORPGs contain activities that might not be play. The author examines the phenomenon of online gaming and…

Let's Play at My House: Effects of the Home Environment on the Social Behavior of Children.

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Jeffers, Victoria W.; Lore, Richard K.

1979-01-01

Results showed that preschool children at home initiated both more positive and aggressive social interactions and were more effective in attracting a visiting child into play than were children away from home. This was the case even when the child at home had been shyer during the first meeting of the children. (JMB)

PLAYING ORIGAMI ENHANCE THE CREATIVITY OF SCHOOL AGED CHILDREN

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Yuni Sufyanti Arief

2017-07-01

Full Text Available Introduction: Critical period for creativity development happened at school aged. Playing Origami is a stimulation that can be done to develop child’s creativity optimally. The aimed of this study was to analyze the effect of playing origami toward creativity development at school age in 4th grade elementary school Krian, Sidoarjo. Method: This study was used a pre experimental and purposive sampling design. The populations were children who age in the sixth until seventh age in 4th grade elementary school Krian, Sidoarjo. There were 41 respondents for this research who met the inclusion criteria. The independent variable was the playing origami while the dependent variable was creativity development of school age. Data were collected by using questionnaire and Figural Creativity test to know the creativity level before and after intervention, and then analyzed by using Wilcoxon Signed Rank Test with significance level of a£0.05. Result: The result showed that there was an effect of play origami toward the creativity development of school age with significant level (p=0.000. Discussion: It can be concluded that playing origami can develop the creativity of school aged children. Every child should be facilitated by provide a chance, supportt and activity that can improve their creativity development that can be useful for them and other people. Further study was recommended to analyze the effect of playing origami on decreasing stress hospitalization.

Play and Adversity: How the Playful Mammalian Brain Withstands Threats and Anxieties

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Siviy, Stephen M.

2010-01-01

Most mammals play, but they do so in a dangerous world. The dynamic relationship between the stresses created by their world and the activity of play helps to explain the evolution of play in mammals, as the author demonstrates in evidence garnered from experiments that introduce elements of fear to rats at play. The author describes the resulting…

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