High precision and stable structures for particle detectors

CERN Document Server

Da Mota Silva, S; Hauviller, Claude

1999-01-01

The central detectors used in High Energy Physics Experiments require the use of light and stable structures capable of supporting delicate and precise radiation detection elements. These structures need to be highly stable under environmental conditions where external vibrations, high radiation levels, temperature and humidity gradients should be taken into account. Their main design drivers are high dimension and dynamic stability, high stiffness to mass ratio and large radiation length. For most applications, these constraints lead us to choose Carbon Fiber Reinforced Plastics ( CFRP) as structural element. The construction of light and stable structures with CFRP for these applications can be achieved by careful design engineering and further confirmation at the prototyping phase. However, the experimental environment can influence their characteristics and behavior. In this case, theuse of adaptive structures could become a solution for this problem. We are studying structures in CFRP with bonded piezoel...

The High Temperature Tensile and Creep Behaviors of High Entropy Superalloy.

Science.gov (United States)

Tsao, Te-Kang; Yeh, An-Chou; Kuo, Chen-Ming; Kakehi, Koji; Murakami, Hideyuki; Yeh, Jien-Wei; Jian, Sheng-Rui

2017-10-04

This article presents the high temperature tensile and creep behaviors of a novel high entropy alloy (HEA). The microstructure of this HEA resembles that of advanced superalloys with a high entropy FCC matrix and L1 2 ordered precipitates, so it is also named as "high entropy superalloy (HESA)". The tensile yield strengths of HESA surpass those of the reported HEAs from room temperature to elevated temperatures; furthermore, its creep resistance at 982 °C can be compared to those of some Ni-based superalloys. Analysis on experimental results indicate that HESA could be strengthened by the low stacking-fault energy of the matrix, high anti-phase boundary energy of the strengthening precipitate, and thermally stable microstructure. Positive misfit between FCC matrix and precipitate has yielded parallel raft microstructure during creep at 982 °C, and the creep curves of HESA were dominated by tertiary creep behavior. To the best of authors' knowledge, this article is the first to present the elevated temperature tensile creep study on full scale specimens of a high entropy alloy, and the potential of HESA for high temperature structural application is discussed.

On the evaluation of elastic follow-up of a high temperature discontinuous structure

International Nuclear Information System (INIS)

Lee, J. M.; Kim, J. B.; Lee, H. Y.; Lee, J. H.

2003-01-01

While high temperature structures of LMR experience inelastic deformation such as plasticity and creep due to high temperature operating temperature of 530∼550 .deg. C, geometric nonlinear structures may undergo elastic follow-up behavior due to the interaction between stiff region and weak region. Thus, careful consideration should be given to the design and analysis of high temperature geometric nonlinear structure. In this study, the elastic follow-up behavior of geometric nonlinear structure has been investigated and the current status of design method implemented in the ASME-NH, Japanese BDS, French RCC-MR, and UK R-5 codes to consider elastic follow-up behavior has been reviewed. It has been shown that the ratio of the stiff region and the weak region and the type of loading affect the elastic follow-up behavior greatly from the detailed inelastic analyses of two bar model and L-shaped structure subjected to various loading situation. The applicability and the conservatism of simplified analysis methods implemented among various design codes need to be studied further

Thermal expansion behavior in fabricated cellular structures

International Nuclear Information System (INIS)

Oruganti, R.K.; Ghosh, A.K.; Mazumder, J.

2004-01-01

Thermal expansion behavior of cellular structures is of interest in applications where undesirable deformation and failure are caused by thermal expansion mismatch. This report describes the role of processing-induced effects and metallurgical aspects of melt-processed cellular structures, such as a bi-material structure designed to contract on heating, as well as uni-material structures of regular and stochastic topology. This bi-material structure utilized the principle of internal geometric constraints to alter the expansion behavior of the internal ligaments to create overall contraction of the structure. Homogenization design method was used to design the structure, and fabrication was by direct metal deposition by laser melting of powder in another part of a joint effort. The degree of porosity and grain size in the fabricated structure are characterized and related to the laser deposition parameters. The structure was found to contract upon heating over a short range of temperature subsequent to which normal expansion ensued. Also examined in this report are uni-material cellular structures, in which internal constraints arise from residual stress variations caused by the fabrication process, and thereby alter their expansion characteristics. A simple analysis of thermal strain of this material supports the observed thermal expansion behavior

Anomalous anisotropic compression behavior of superconducting CrAs under high pressure

Science.gov (United States)

Yu, Zhenhai; Wu, Wei; Hu, Qingyang; Zhao, Jinggeng; Li, Chunyu; Yang, Ke; Cheng, Jinguang; Luo, Jianlin; Wang, Lin; Mao, Ho-kwang

2015-01-01

CrAs was observed to possess the bulk superconductivity under high-pressure conditions. To understand the superconducting mechanism and explore the correlation between the structure and superconductivity, the high-pressure structural evolution of CrAs was investigated using the angle-dispersive X-ray diffraction (XRD) method. The structure of CrAs remains stable up to 1.8 GPa, whereas the lattice parameters exhibit anomalous compression behaviors. With increasing pressure, the lattice parameters a and c both demonstrate a nonmonotonic change, and the lattice parameter b undergoes a rapid contraction at ∼0.18−0.35 GPa, which suggests that a pressure-induced isostructural phase transition occurs in CrAs. Above the phase transition pressure, the axial compressibilities of CrAs present remarkable anisotropy. A schematic band model was used to address the anomalous compression behavior of CrAs. The present results shed light on the structural and related electronic responses to high pressure, which play a key role toward understanding the superconductivity of CrAs. PMID:26627230

Brain structural correlates of risk-taking behavior and effects of peer influence in adolescents.

Directory of Open Access Journals (Sweden)

Myoung Soo Kwon

Full Text Available Adolescents are characterized by impulsive risky behavior, particularly in the presence of peers. We discriminated high and low risk-taking male adolescents aged 18-19 years by assessing their propensity for risky behavior and vulnerability to peer influence with personality tests, and compared structural differences in gray and white matter of the brain with voxel-based morphometry (VBM and diffusion tensor imaging (DTI, respectively. We also compared the brain structures according to the participants' actual risk-taking behavior in a simulated driving task with two different social conditions making up a peer competition situation. There was a discrepancy between the self-reported personality test results and risky driving behavior (running through an intersection with traffic lights turning yellow, chancing a collision with another vehicle. Comparison between high and low risk-taking adolescents according to personality test results revealed no significant difference in gray matter volume and white matter integrity. However, comparison according to actual risk-taking behavior during task performance revealed significantly higher white matter integrity in the high risk-taking group, suggesting that increased risky behavior during adolescence is not necessarily attributed to the immature brain as conventional wisdom says.

Modelling and simulation of the influence of forming processes on the structural behavior of high strength steels

International Nuclear Information System (INIS)

Gelin, J.C.; Thibaud, S.; Boudeau, N.

2005-01-01

The paper first describes experiments and modeling concerning the identification of material behavior for high strength steels with phase transformations associated to plastic deformation. The experiments consist of tensile and bulging tests carried out on 316L stainless steels and TRIP 700 steels used in automotive industry. These experiments have permitted to determine the hardening curves of such materials vs. the martensite volume fraction associated to plastic deformation. It has been demonstrated that the stress triaxiality has a major role in the martenstic transformation and a model is proposed to define the flow stress vs. effective strain accounting planar anisotropy and variation of martenstic volume fraction. Then a plasticity model has been proposed in an anisotropic form and the related flow rules have been defined. The resulting model has been implemented in different finite elements software, and applied in numerical simulations of stamping and hydroforming of typical components to prove the effects of forming processes on the resulting properties of the components. Finally, the structural behavior of the resulting components is investigated and the effects of forming processes on the resulting structural behaviour are analyzed. Two cases are presented, one concerns the deep drawing of a cylindrical cup and the other concerns the stamping of a closed U channel used as a structural part for crash frames. Is has been clearly proved that the variation of martensite volume fraction arising during processing has a strong influence on the resulting behaviour of the parts considering springback and crash resistance

Elastodynamic behavior of the three dimensional layer-by-layer metamaterial structure

International Nuclear Information System (INIS)

Aravantinos-Zafiris, N.; Sigalas, M. M.; Economou, E. N.

2014-01-01

In this work, we numerically investigate for the first time the elastodynamic behavior of a three dimensional layer-by-layer rod structure, which is easy to fabricate and has already proved to be very efficient as a photonic crystal. The Finite Difference Time Domain method was used for the numerical calculations. For the rods, several materials were examined and the effects of all the geometric parameters of the structure were also numerically investigated. Additionally, two modifications of the structure were included in our calculations. The results obtained here (for certain geometric parameters), exhibiting a high ratio of longitudinal over transverse sound velocity and therefore a close approach to ideal pentamode behavior over a frequency range, clearly show that the layer-by-layer rod structure, besides being an efficient photonic crystal, is a very serious contender as an elastodynamic metamaterial.

High temperature structural silicides

International Nuclear Information System (INIS)

Petrovic, J.J.

1997-01-01

Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi 2 -based materials, which are borderline ceramic-intermetallic compounds. MoSi 2 single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi 2 possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi 2 -Si 3 N 4 composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi 2 -based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing

A Fully Automated High-Throughput Zebrafish Behavioral Ototoxicity Assay.

Science.gov (United States)

Todd, Douglas W; Philip, Rohit C; Niihori, Maki; Ringle, Ryan A; Coyle, Kelsey R; Zehri, Sobia F; Zabala, Leanne; Mudery, Jordan A; Francis, Ross H; Rodriguez, Jeffrey J; Jacob, Abraham

2017-08-01

Zebrafish animal models lend themselves to behavioral assays that can facilitate rapid screening of ototoxic, otoprotective, and otoregenerative drugs. Structurally similar to human inner ear hair cells, the mechanosensory hair cells on their lateral line allow the zebrafish to sense water flow and orient head-to-current in a behavior called rheotaxis. This rheotaxis behavior deteriorates in a dose-dependent manner with increased exposure to the ototoxin cisplatin, thereby establishing itself as an excellent biomarker for anatomic damage to lateral line hair cells. Building on work by our group and others, we have built a new, fully automated high-throughput behavioral assay system that uses automated image analysis techniques to quantify rheotaxis behavior. This novel system consists of a custom-designed swimming apparatus and imaging system consisting of network-controlled Raspberry Pi microcomputers capturing infrared video. Automated analysis techniques detect individual zebrafish, compute their orientation, and quantify the rheotaxis behavior of a zebrafish test population, producing a powerful, high-throughput behavioral assay. Using our fully automated biological assay to test a standardized ototoxic dose of cisplatin against varying doses of compounds that protect or regenerate hair cells may facilitate rapid translation of candidate drugs into preclinical mammalian models of hearing loss.

Structural analysis of behavioral networks from the Internet

International Nuclear Information System (INIS)

Meiss, M R; Menczer, F; Vespignani, A

2008-01-01

In spite of the Internet's phenomenal growth and social impact, many aspects of the collective communication behavior of its users are largely unknown. Understanding the structure and dynamics of the behavioral networks that connect users with each other and with services across the Internet is key to modeling the network and designing future applications. We present a characterization of the properties of the behavioral networks generated by several million users of the Abilene (Internet2) network. Structural features of these networks offer new insights into scaling properties of network activity and ways of distinguishing particular patterns of traffic. For example, we find that the structure of the behavioral network associated with Web activity is characterized by such extreme heterogeneity as to challenge any simple attempt to model Web server traffic

Structural analysis of behavioral networks from the Internet

Energy Technology Data Exchange (ETDEWEB)

Meiss, M R; Menczer, F [Department of Computer Science, Indiana University, Bloomington, IN 47405 (United States); Vespignani, A [Department of Informatics, Indiana University, Bloomington, IN 47408 (United States)], E-mail: mmeiss@indiana.edu

2008-06-06

In spite of the Internet's phenomenal growth and social impact, many aspects of the collective communication behavior of its users are largely unknown. Understanding the structure and dynamics of the behavioral networks that connect users with each other and with services across the Internet is key to modeling the network and designing future applications. We present a characterization of the properties of the behavioral networks generated by several million users of the Abilene (Internet2) network. Structural features of these networks offer new insights into scaling properties of network activity and ways of distinguishing particular patterns of traffic. For example, we find that the structure of the behavioral network associated with Web activity is characterized by such extreme heterogeneity as to challenge any simple attempt to model Web server traffic.

Nonlinear system identification of smart structures under high impact loads

International Nuclear Information System (INIS)

Sarp Arsava, Kemal; Kim, Yeesock; El-Korchi, Tahar; Park, Hyo Seon

2013-01-01

The main purpose of this paper is to develop numerical models for the prediction and analysis of the highly nonlinear behavior of integrated structure control systems subjected to high impact loading. A time-delayed adaptive neuro-fuzzy inference system (TANFIS) is proposed for modeling of the complex nonlinear behavior of smart structures equipped with magnetorheological (MR) dampers under high impact forces. Experimental studies are performed to generate sets of input and output data for training and validation of the TANFIS models. The high impact load and current signals are used as the input disturbance and control signals while the displacement and acceleration responses from the structure–MR damper system are used as the output signals. The benchmark adaptive neuro-fuzzy inference system (ANFIS) is used as a baseline. Comparisons of the trained TANFIS models with experimental results demonstrate that the TANFIS modeling framework is an effective way to capture nonlinear behavior of integrated structure–MR damper systems under high impact loading. In addition, the performance of the TANFIS model is much better than that of ANFIS in both the training and the validation processes. (paper)

High risk sexual behaviors for HIV among the in-school youth in Swaziland: a structural equation modeling approach.

Science.gov (United States)

Sacolo, Hlengiwe Nokuthula; Chung, Min-Huey; Chu, Hsin; Liao, Yuan-Mei; Chen, Chiung-Hua; Ou, Keng-Liang; Chang, Lu-I; Chou, Kuei-Ru

2013-01-01

Global efforts in response to the increased prevalence of the human immunodeficiency virus (HIV) are mainly aimed at reducing high risk sexual behaviors among young people. However, knowledge regarding intentions of young people to engage in protective sexual behaviors is still lacking in many countries around the world, especially in Sub-Saharan Africa where prevalence of human immunodeficiency virus is the highest. The objective of this study was to test the theory of planned behavior (TPB) for predicting factors associated with protective sexual behaviors, including sexual abstinence and condom use, among in-school youths aged between 15 and 19 years in Swaziland. This cross-sectional survey was conducted using a anonymous questionnaire. A two-stage stratified and cluster random sampling method was used. Approximately one hundred pupils from each of four schools agreed to participate in the study, providing a total sample size of 403 pupils of which 369 were ultimately included for data analysis. The response rate was 98%. Structural equation modeling was used to analyse hypothesized paths. The TPB model used in this study was effective in predicting protective sexual behavior among Swazi in-school youths, as shown by model fit indices. All hypothesized constructs significantly predicted intentions for abstinence and condom use, except perceived abstinence controls. Subjective norms were the strongest predictors of intention for premarital sexual abstinence; however, perceived controls for condom use were the strongest predictors of intention for condom use. Our findings support application of the model in predicting determinants of condom use and abstinence intentions among Swazi in-school youths.

High Risk Sexual Behaviors for HIV among the In-School Youth in Swaziland: A Structural Equation Modeling Approach

Science.gov (United States)

Chu, Hsin; Liao, Yuan-Mei; Chen, Chiung-Hua; Ou, Keng-Liang; Chang, Lu-I; Chou, Kuei-Ru

2013-01-01

Background Global efforts in response to the increased prevalence of the human immunodeficiency virus (HIV) are mainly aimed at reducing high risk sexual behaviors among young people. However, knowledge regarding intentions of young people to engage in protective sexual behaviors is still lacking in many countries around the world, especially in Sub-Saharan Africa where prevalence of human immunodeficiency virus is the highest. The objective of this study was to test the theory of planned behavior (TPB) for predicting factors associated with protective sexual behaviors, including sexual abstinence and condom use, among in-school youths aged between 15 and 19 years in Swaziland. Methods This cross-sectional survey was conducted using a anonymous questionnaire. A two-stage stratified and cluster random sampling method was used. Approximately one hundred pupils from each of four schools agreed to participate in the study, providing a total sample size of 403 pupils of which 369 were ultimately included for data analysis. The response rate was 98%. Structural equation modeling was used to analyse hypothesized paths. Results The TPB model used in this study was effective in predicting protective sexual behavior among Swazi in-school youths, as shown by model fit indices. All hypothesized constructs significantly predicted intentions for abstinence and condom use, except perceived abstinence controls. Subjective norms were the strongest predictors of intention for premarital sexual abstinence; however, perceived controls for condom use were the strongest predictors of intention for condom use. Conclusions Our findings support application of the model in predicting determinants of condom use and abstinence intentions among Swazi in-school youths. PMID:23861756

Evaluation of Dynamic Deformation Behaviors in Metallic Materials under High Strain-Rates Using Taylor Bar Impact Test

Energy Technology Data Exchange (ETDEWEB)

Bae, Kyung Oh; Shin, Hyung Seop [Andong National Univ., Andong (Korea, Republic of)

2016-09-15

To ensure the reliability and safety of various mechanical systems in accordance with their high-speed usage, it is necessary to evaluate the dynamic deformation behavior of structural materials under impact load. However, it is not easy to understand the dynamic deformation behavior of the structural materials using experimental methods in the high strain-rate range exceeding 10{sup 4} s{sup -1}. In this study, the Taylor bar impact test was conducted to investigate the dynamic deformation behavior of metallic materials in the high strain-rate region, using a high-speed photography system. Numerical analysis of the Taylor bar impact test was performed using AUTODYN S/W. The results of the analysis were compared with the experimental results, and the material behavior in the high strain-rate region was discussed.

High temperature structural sandwich panels

Science.gov (United States)

Papakonstantinou, Christos G.

High strength composites are being used for making lightweight structural panels that are being employed in aerospace, naval and automotive structures. Recently, there is renewed interest in use of these panels. The major problem of most commercial available sandwich panels is the fire resistance. A recently developed inorganic matrix is investigated for use in cases where fire and high temperature resistance are necessary. The focus of this dissertation is the development of a fireproof composite structural system. Sandwich panels made with polysialate matrices have an excellent potential for use in applications where exposure to high temperatures or fire is a concern. Commercial available sandwich panels will soften and lose nearly all of their compressive strength temperatures lower than 400°C. This dissertation consists of the state of the art, the experimental investigation and the analytical modeling. The state of the art covers the performance of existing high temperature composites, sandwich panels and reinforced concrete beams strengthened with Fiber Reinforced Polymers (FRP). The experimental part consists of four major components: (i) Development of a fireproof syntactic foam with maximum specific strength, (ii) Development of a lightweight syntactic foam based on polystyrene spheres, (iii) Development of the composite system for the skins. The variables are the skin thickness, modulus of elasticity of skin and high temperature resistance, and (iv) Experimental evaluation of the flexural behavior of sandwich panels. Analytical modeling consists of a model for the flexural behavior of lightweight sandwich panels, and a model for deflection calculations of reinforced concrete beams strengthened with FRP subjected to fatigue loading. The experimental and analytical results show that sandwich panels made with polysialate matrices and ceramic spheres do not lose their load bearing capability during severe fire exposure, where temperatures reach several

High risk sexual behaviors for HIV among the in-school youth in Swaziland: a structural equation modeling approach.

Directory of Open Access Journals (Sweden)

Hlengiwe Nokuthula Sacolo

Full Text Available BACKGROUND: Global efforts in response to the increased prevalence of the human immunodeficiency virus (HIV are mainly aimed at reducing high risk sexual behaviors among young people. However, knowledge regarding intentions of young people to engage in protective sexual behaviors is still lacking in many countries around the world, especially in Sub-Saharan Africa where prevalence of human immunodeficiency virus is the highest. The objective of this study was to test the theory of planned behavior (TPB for predicting factors associated with protective sexual behaviors, including sexual abstinence and condom use, among in-school youths aged between 15 and 19 years in Swaziland. METHODS: This cross-sectional survey was conducted using a anonymous questionnaire. A two-stage stratified and cluster random sampling method was used. Approximately one hundred pupils from each of four schools agreed to participate in the study, providing a total sample size of 403 pupils of which 369 were ultimately included for data analysis. The response rate was 98%. Structural equation modeling was used to analyse hypothesized paths. RESULTS: The TPB model used in this study was effective in predicting protective sexual behavior among Swazi in-school youths, as shown by model fit indices. All hypothesized constructs significantly predicted intentions for abstinence and condom use, except perceived abstinence controls. Subjective norms were the strongest predictors of intention for premarital sexual abstinence; however, perceived controls for condom use were the strongest predictors of intention for condom use. CONCLUSIONS: Our findings support application of the model in predicting determinants of condom use and abstinence intentions among Swazi in-school youths.

Long-Term Structural Health Monitoring System for a High-Speed Railway Bridge Structure

Directory of Open Access Journals (Sweden)

You-Liang Ding

2015-01-01

Full Text Available Nanjing Dashengguan Bridge, which serves as the shared corridor crossing Yangtze River for both Beijing-Shanghai high-speed railway and Shanghai-Wuhan-Chengdu railway, is the first 6-track high-speed railway bridge with the longest span throughout the world. In order to ensure safety and detect the performance deterioration during the long-time service of the bridge, a Structural Health Monitoring (SHM system has been implemented on this bridge by the application of modern techniques in sensing, testing, computing, and network communication. The SHM system includes various sensors as well as corresponding data acquisition and transmission equipment for automatic data collection. Furthermore, an evaluation system of structural safety has been developed for the real-time condition assessment of this bridge. The mathematical correlation models describing the overall structural behavior of the bridge can be obtained with the support of the health monitoring system, which includes cross-correlation models for accelerations, correlation models between temperature and static strains of steel truss arch, and correlation models between temperature and longitudinal displacements of piers. Some evaluation results using the mean value control chart based on mathematical correlation models are presented in this paper to show the effectiveness of this SHM system in detecting the bridge’s abnormal behaviors under the varying environmental conditions such as high-speed trains and environmental temperature.

Long-Term Structural Health Monitoring System for a High-Speed Railway Bridge Structure

Science.gov (United States)

Wu, Lai-Yi

2015-01-01

Nanjing Dashengguan Bridge, which serves as the shared corridor crossing Yangtze River for both Beijing-Shanghai high-speed railway and Shanghai-Wuhan-Chengdu railway, is the first 6-track high-speed railway bridge with the longest span throughout the world. In order to ensure safety and detect the performance deterioration during the long-time service of the bridge, a Structural Health Monitoring (SHM) system has been implemented on this bridge by the application of modern techniques in sensing, testing, computing, and network communication. The SHM system includes various sensors as well as corresponding data acquisition and transmission equipment for automatic data collection. Furthermore, an evaluation system of structural safety has been developed for the real-time condition assessment of this bridge. The mathematical correlation models describing the overall structural behavior of the bridge can be obtained with the support of the health monitoring system, which includes cross-correlation models for accelerations, correlation models between temperature and static strains of steel truss arch, and correlation models between temperature and longitudinal displacements of piers. Some evaluation results using the mean value control chart based on mathematical correlation models are presented in this paper to show the effectiveness of this SHM system in detecting the bridge's abnormal behaviors under the varying environmental conditions such as high-speed trains and environmental temperature. PMID:26451387

Structural behavior of cable superconductors

International Nuclear Information System (INIS)

Becker, H.; Marston, P.

1983-01-01

The structural properties of cable superconductor coils, for particle accelerators such as the Tevatron and the CBA (Colliding Beam Accelerator), depend upon direction of loading. For compression perpendicular to the ''flat faces'' of the conductor, the coils exhibit nonlinear, inelastic and time dependent behavior. The same is true for ''inplane'' compression loading perpendicular to the conductor edges. In the lengthwise direction, the coils display tension and compression stress-strain curves typical of structural metals. The loading of primary concern is compression perpendicular to the conductor faces since deformations in that direction can have a major influence on magnetic field quality. However, the coil behavior under that condition is uncertain because of the nonlinear stress strain curve complicated by creep and relaxation at the stress levels induced by preloading and Lorentz forces. Furthermore, the stiffness of the loading fixture appears to influence the data as shown by results from tests run under different conditions at Berkeley, Brookhaven and MIT. The paper displays test data on stress-strain curves for all three loading directions. Results are presented for RT, 77 K and 4 K behavior. Data of various investigators are compared. The applicability of a relatively simple power law between stress and strain is depicted

High temperature oxidation behavior of TiAl-based intermetallics

International Nuclear Information System (INIS)

Stroosnijder, M.F.; Sunderkoetter, J.D.; Haanappel, V.A.C.

1996-01-01

TiAl-based intermetallic compounds have attracted considerable interest as structural materials for high-temperature applications due to their low density and substantial mechanical strength at high temperatures. However, one major drawback hindering industrial application arises from the insufficient oxidation resistance at temperatures beyond 700 C. In the present contribution some general aspects of high temperature oxidation of TiAl-based intermetallics will be presented. This will be followed by a discussion of the influence of alloying elements, in particular niobium, and of the effect of nitrogen in the oxidizing environment on the high temperature oxidation behavior of such materials

Effect of Co content on structure and magnetic behaviors of high induction Fe-based amorphous alloys

Energy Technology Data Exchange (ETDEWEB)

Roy, Rajat K., E-mail: rajat@nmlindia.org; Panda, Ashis K.; Mitra, Amitava

2016-11-15

The replacement of Fe with Co is investigated in the (Fe{sub 1−x}Co{sub x}){sub 79}Si{sub 8.5}B{sub 8.5}Nb{sub 3}Cu{sub 1} (x=0, 0.05, 0.2, 0.35, 0.5) amorphous alloys. The alloys are synthesized in the forms of ribbons by single roller melt spinning technique, and the structural and magnetic properties of annealed ribbons are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM), B–H curve tracer, respectively. All as-cast alloys are structurally amorphous, however, their magnetic properties are varying with Co addition. The Co addition within 5–20 at% results in moderate thermal stability, saturation induction, Curie temperature and lowest coercivity, while 35 at% Co causes highest saturation induction, coercivity, Curie temperature and lowest thermal stability. On devitrification, the magnetic properties change with the generation of α-FeCo nanocrystallites and (FeCo){sub 23}B{sub 6}, Fe{sub 2}B phases during primary and secondary crystallization stages, respectively. A small amount Co is advantageous for maintaining finer nanocrystallites in amorphous matrix even after annealing at 600 °C, leading to high saturation magnetization (>1.5 T) and low coercivity (~35 A/m). The improved magnetic properties at elevated temperatures indicate these alloys have a potential for high frequency transformer core applications. - Highlights: • The structural and magnetic behaviors of Fe based amorphous alloys have been investigated with the effect of Co content. • The Co has no adverse effect on amorphization of alloys. • A small amount Co causes the superior improvement of magnetic properties at elevated temperatures. • Therefore, it is important not only for academic research but also for industrial applied research.

On the Mechanical Behavior of Advanced Composite Material Structures

Science.gov (United States)

Vinson, Jack

During the period between 1993 and 2004, the author, as well as some colleagues and graduate students, had the honor to be supported by the Office of Naval Research to conduct research in several aspects of the behavior of structures composed of composite materials. The topics involved in this research program were numerous, but all contributed to increasing the understanding of how various structures that are useful for marine applications behaved. More specifically, the research topics focused on the reaction of structures that were made of fiber reinforced polymer matrix composites when subjected to various loads and environmental conditions. This included the behavior of beam, plate/panel and shell structures. It involved studies that are applicable to fiberglass, graphite/carbon and Kevlar fibers imbedded in epoxy, polyester and other polymeric matrices. Unidirectional, cross-ply, angle ply, and woven composites were involved, both in laminated, monocoque as well as in sandwich constructions. Mid-plane symmetric as well as asymmetric laminates were studied, the latter involving bending-stretching coupling and other couplings that only can be achieved with advanced composite materials. The composite structures studied involved static loads, dynamic loading, shock loading as well as thermal and hygrothermal environments. One major consideration was determining the mechanical properties of composite materials subjected to high strain rates because the mechanical properties vary so significantly as the strain rate increases. A considerable number of references are cited for further reading and study for those interested.

Evaluation of structural behavior, geological and hydrogeological characteristics

International Nuclear Information System (INIS)

Kim, Jhin Wung; Kim, Sun Hoon; Kim, Dae Hong; Choi, Kyu Sup

1992-02-01

In order to understand the behavior of an underground structure properly, this report includes the study on the structural behavior of rock masses surrounding underground openings considering the effect of excavation. Before analyzing the underground structure, the followings are studied: initial stress distribution before excavation, stress release and redistribution due to the sequential excavation, comparison of analysis methods, discussions on numerical simulation techniques for the sequential excavation and an numerical analysis modeling. The underground structure in then analyzed using the finite element and distinct element methods of analysis considering the effect of sequential excavation, Based on the results of the analysis, the followings are discussed: shape of the opening, distance between openings, method and sequence of excavation, and structural reinforcement. (Author)

High-strength concrete and the design of power plant structures

International Nuclear Information System (INIS)

Puttonen, J.

1991-01-01

Based on the literature, the design of high-strength concrete structures and the suitability of high-strength concrete for the power plant structures have been studied. Concerning the behavior of structures, a basic difference between the high-strength concrete and the traditional one is that the ductility of the high-strength concrete is smaller. In the design, the non-linear stress-strain relationship of the high-strength concrete has to be taken into account. The use of the high-strength concrete is economical if the strength of the material can be utilized. In the long term, the good durability and wear resistance of the high-strength concrete increases the economy of the material. Because of the low permeability of the high-strength concrete, it is a potential material in the safety-related structures of nuclear power plants. The study discovered no particular power plant structure which would always be economical to design of high-strength concrete. However, the high-strength concrete was found to be a competitive material in general

Community Structural Instability, Anomie, Imitation and Adolescent Suicidal Behavior

Science.gov (United States)

Thorlindsson, Thorolfur; Bernburg, Jon Gunnar

2009-01-01

The current study examines the contextual effects of community structural characteristics, as well as the mediating role of key social mechanisms, on youth suicidal behavior in Iceland. We argue that the contextual influence of community structural instability on youth suicidal behavior should be mediated by weak attachment to social norms and…

Elemental redistribution behavior in tellurite glass induced by high repetition rate femtosecond laser irradiation

International Nuclear Information System (INIS)

Teng, Yu; Zhou, Jiajia; Khisro, Said Nasir; Zhou, Shifeng; Qiu, Jianrong

2014-01-01

Highlights: • Abnormal elements redistribution behavior was observed in tellurite glass. • The refractive index and Raman intensity distribution changed significantly. • The relative glass composition remained unchanged while the glass density changed. • First time report on the abnormal element redistribution behavior in glass. • The glass network structure determines the elemental redistribution behavior. - Abstract: The success in the fabrication of micro-structures in glassy materials using femtosecond laser irradiation has proved its potential applications in the construction of three-dimensional micro-optical components or devices. In this paper, we report the elemental redistribution behavior in tellurite glass after the irradiation of high repetition rate femtosecond laser pulses. The relative glass composition remained unchanged while the glass density changed significantly, which is quite different from previously reported results about the high repetition rate femtosecond laser induced elemental redistribution in silicate glasses. The involved mechanism is discussed with the conclusion that the glass network structure plays the key role to determine the elemental redistribution. This observation not only helps to understand the interaction process of femtosecond laser with glassy materials, but also has potential applications in the fabrication of micro-optical devices

The tensile behavior of Ti36Ni49Hf15 high temperature shape memory alloy

International Nuclear Information System (INIS)

Wang, Y.Q.; Zheng, Y.F.; Cai, W.; Zhao, L.C.

1999-01-01

Recently, ternary Ti-Ni-Hf alloys have attracted great interest in the field of high temperature shape memory materials research and development. Extensive studies have been made on its manufacture process, constitutional phases, phase transformation behavior, the structure, substructure and interface structure of martensite and the precipitation behavior during ageing. Yet up to date there is no report about the fundamental mechanical properties of Ti-Ni-Hf alloys, such as the stress-strain data, the variation laws of the yield strength and elongation with the temperature. In the present study, tensile tests at various temperatures are employed to investigate the mechanical behavior of Ti-Ni-Hf alloy with different matrix structures, from full martensite to full parent phase structure, with the corresponding deformation mechanism discussed

Thermomechanics of composite structures under high temperatures

CERN Document Server

Dimitrienko, Yu I

2016-01-01

This pioneering book presents new models for the thermomechanical behavior of composite materials and structures taking into account internal physico-chemical transformations such as thermodecomposition, sublimation and melting at high temperatures (up to 3000 K). It is of great importance for the design of new thermostable materials and for the investigation of reliability and fire safety of composite structures. It also supports the investigation of interaction of composites with laser irradiation and the design of heat-shield systems. Structural methods are presented for calculating the effective mechanical and thermal properties of matrices, fibres and unidirectional, reinforced by dispersed particles and textile composites, in terms of properties of their constituent phases. Useful calculation methods are developed for characteristics such as the rate of thermomechanical erosion of composites under high-speed flow and the heat deformation of composites with account of chemical shrinkage. The author expan...

Effect of high temperature on integrity of concrete containment structures

International Nuclear Information System (INIS)

Bhat, P.D.

1986-01-01

The effect of high temperature on concrete material properties and structural behavior are studied in order to relate these effects to the performance of concrete containment structures. Salient data obtained from a test program undertaken to study the behavior of a restrained concrete structure under thermal gradient loads up to its ultimate limit are described. The preliminary results indicate that concrete material properties can be considered to remain unaltered up to temperatures of 100 0 C. The presence of thermal gradients did not significantly affect the structures ultimate mechanical load capacity. Relaxation of restraint forces due to creep was found to be an important factor. The test findings are compared with the observations made in available literature. The effect of test findings on the integrity analysis of a containment structure are discussed. The problem is studied from the viewpoint of a CANDU heavy water reactor containment

Virtual Testing of Composite Structures Made of High Entropy Alloys and Steel

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Victor Geantă

2017-11-01

Full Text Available High entropy alloys (HEA are metallic materials obtained from a mixture of at least five atomic-scale chemical elements. They are characterized by high mechanical strength, good thermal stability and hardenability. AlCrFeCoNi alloys have high compression strength and tensile strength values of 2004 MPa, respectively 1250 MPa and elongation of about 32.7%. These materials can be used to create HEA-steel type composite structures which resist to dynamic deformation during high speed impacts. The paper presents four different composite structures made from a combination of HEA and carbon steel plates, using different joining processes. The numerical simulation of the impact behavior of the composite structures was performed by virtual methods, taking into account the mechanical properties of both materials. For analyzing each constructive variant, three virtual shootings were designed, using a 7.62 × 39 mm cal. incendiary armor-piercing bullet and different impact velocities. The best ballistic behavior was provided by the composite structures obtained by welding and brazing that have good continuity and rigidity. The other composite structures, which do not have good surface adhesion, show high fragmentation risk, because the rear plate can fragment on the axis of shooting due to the combination between the shock waves and the reflected ones. The order of materials in the composite structure has a very important role in decreasing the impact energy.

Band structure and phonon properties of lithium fluoride at high pressure

Energy Technology Data Exchange (ETDEWEB)

Panchal, J. M., E-mail: amitjignesh@yahoo.co.in [Government Engineering College, Gandhinagar 382028, Gujarat (India); Department of Physics, University School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat (India); Joshi, Mitesh [Government Polytechnic for Girls, Athwagate, Surat395001, Gujarat (India); Gajjar, P. N., E-mail: pngajjar@rediffmail.com [Department of Physics, University School of Sciences, Gujarat University, Ahmedabad 380009, Gujarat (India)

2016-05-23

High pressure structural and electronic properties of Lithium Fluoride (LiF) have been studied by employing an ab-initio pseudopotential method and a linear response scheme within the density functional theory (DFT) in conjunction with quasi harmonic Debye model. The band structure and electronic density of states conforms that the LiF is stable and is having insulator behavior at ambient as well as at high pressure up to 1 Mbar. Conclusions based on Band structure, phonon dispersion and phonon density of states are outlined.

Band structure and phonon properties of lithium fluoride at high pressure

International Nuclear Information System (INIS)

Panchal, J. M.; Joshi, Mitesh; Gajjar, P. N.

2016-01-01

High pressure structural and electronic properties of Lithium Fluoride (LiF) have been studied by employing an ab-initio pseudopotential method and a linear response scheme within the density functional theory (DFT) in conjunction with quasi harmonic Debye model. The band structure and electronic density of states conforms that the LiF is stable and is having insulator behavior at ambient as well as at high pressure up to 1 Mbar. Conclusions based on Band structure, phonon dispersion and phonon density of states are outlined.

Using Behavioral Economics to Design Physician Incentives That Deliver High-Value Care.

Science.gov (United States)

Emanuel, Ezekiel J; Ubel, Peter A; Kessler, Judd B; Meyer, Gregg; Muller, Ralph W; Navathe, Amol S; Patel, Pankaj; Pearl, Robert; Rosenthal, Meredith B; Sacks, Lee; Sen, Aditi P; Sherman, Paul; Volpp, Kevin G

2016-01-19

Behavioral economics provides insights about the development of effective incentives for physicians to deliver high-value care. It suggests that the structure and delivery of incentives can shape behavior, as can thoughtful design of the decision-making environment. This article discusses several principles of behavioral economics, including inertia, loss aversion, choice overload, and relative social ranking. Whereas these principles have been applied to motivate personal health decisions, retirement planning, and savings behavior, they have been largely ignored in the design of physician incentive programs. Applying these principles to physician incentives can improve their effectiveness through better alignment with performance goals. Anecdotal examples of successful incentive programs that apply behavioral economics principles are provided, even as the authors recognize that its application to the design of physician incentives is largely untested, and many outstanding questions exist. Application and rigorous evaluation of infrastructure changes and incentives are needed to design payment systems that incentivize high-quality, cost-conscious care.

Structured dyadic behavior therapy processes for ADHD intervention.

Science.gov (United States)

Curtis, David F

2014-03-01

Children with Attention-Deficit/Hyperactivity Disorder (ADHD) present significant problems with behavioral disinhibition that often negatively affect their peer relationships. Although behavior therapies for ADHD have traditionally aimed to help parents and teachers better manage children's ADHD-related behaviors, therapy processes seldom use peer relationships to implement evidence-based behavioral principles. This article introduces Structured Dyadic Behavior Therapy as a milieu for introducing effective behavioral techniques within a socially meaningful context. Establishing collaborative behavioral goals, benchmarking, and redirection strategies are discussed to highlight how in-session dyadic processes can be used to promote more meaningful reinforcement and change for children with ADHD. Implications for improving patient care, access to care, and therapist training are also discussed.

Dynamical behavior of price forecasting in structures of group correlations

Science.gov (United States)

Lim, Kyuseong; Kim, Soo Yong; Kim, Kyungsik

2015-07-01

We investigate the prediction of the future prices from the structures and the networks of the companies in special financial groups. After the financial group network has been constructed from the value of the high cross-correlation, each company in a group is simulated and analyzed how it buys or sells stock is anaylzed and how it makes rational investments is forecasted. In the shortmemory behavior rather than the long-memory behavior, each company among a group can make a rational investment decision by using a stochastic evolution rule in the financial network. In particular, we simulate and analyze the investment situation in connection with the empirical data and the simulated result.

Crash simulation of hybrid structures considering the stress and strain rate dependent material behavior of thermoplastic materials

Science.gov (United States)

Hopmann, Ch.; Schöngart, M.; Weber, M.; Klein, J.

2015-05-01

Thermoplastic materials are more and more used as a light weight replacement for metal, especially in the automotive industry. Since these materials do not provide the mechanical properties, which are required to manufacture supporting elements like an auto body or a cross bearer, plastics are combined with metals in so called hybrid structures. Normally, the plastics components are joined to the metal structures using different technologies like welding or screwing. Very often, the hybrid structures are made of flat metal parts, which are stiffened by a reinforcement structure made of thermoplastic materials. The loads on these structures are very often impulsive, for example in the crash situation of an automobile. Due to the large stiffness variation of metal and thermoplastic materials, complex states of stress and very high local strain rates occur in the contact zone under impact conditions. Since the mechanical behavior of thermoplastic materials is highly dependent on these types of load, the crash failure of metal plastic hybrid parts is very complex. The problem is that the normally used strain rate dependent elastic/plastic material models are not capable to simulate the mechanical behavior of thermoplastic materials depended on the state of stress. As part of a research project, a method to simulate the mechanical behavior of hybrid structures under impact conditions is developed at the IKV. For this purpose, a specimen for the measurement of mechanical properties dependet on the state of stress and a method for the strain rate depended characterization of thermoplastic materials were developed. In the second step impact testing is performed. A hybrid structure made from a metal sheet and a reinforcement structure of a Polybutylenterephthalat Polycarbonate blend is tested under impact conditions. The measured stress and strain rate depended material data are used to simulate the mechanical behavior of the hybrid structure under highly dynamic load with

Long term bending behavior of ultra-high performance concrete (UHPC beams

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Gheorghe-Alexandru BARBOS

2015-12-01

Full Text Available Unlike normal concrete (NC the behavior of ultra-high performance concrete (UHPC is different under long-term efforts, if we refer to creep, shrinkage or long-term deflections. It is well known that UHPC has special properties, like compressive strength higher than 150 MPa and tensile strength higher than 20 MPa - in case of UHPC reinforced with steel-fibers. Nevertheless, UHPC behavior is not completely elucidated in what concerns creep straining or serviceability behavior in case of structural elements. Some studies made on UHPC samples shown that creep is significantly reduced if the concrete is subjected to heat treatment and if it contains steel-fiber reinforcement. Relating thereto, it is important to know how does structural elements made of this type of concrete works in service life under long-term loadings. The results obtained on UHPC samples, regarding creep straining from tension or compression efforts may not be generalized in case of structural elements (e.g. beams, slabs, columns subjected to bending. By performing this study, it was aimed to understand the influence of heat treatment and steel-fiber addition on the rheological phenomena of UHPC bended beams.

Plasma Structure and Behavior of Miniature Ring-Cusp Discharges

Science.gov (United States)

Mao, Hann-Shin

Miniature ring-cusp ion thrusters provide a unique blend of high efficiencies and millinewton level thrust for future spacecraft. These thrusters are attractive as a primary propulsion for small satellites that require a high delta V, and as a secondary propulsion for larger spacecraft that require precision formation flying, disturbance rejection, or attitude control. To ensure desirable performance throughout the life of such missions, an advancement in the understanding of the plasma structure and behavior of miniature ring-cusp discharges is required. A research model was fabricated to provide a simplified experimental test bed for the analysis of the plasma discharge chamber of a miniature ion thruster. The plasma source allowed for spatially resolved measurements with a Langmuir probe along a meridian plane. Probe measurements yielded plasma density, electron temperature, and plasma potential data. The magnetic field strength was varied along with the discharge current to determine the plasma behavior under various conditions. The structure of the plasma properties were found to be independent of the discharge power under the proper scaling. It was concluded that weaker magnetic fields can improve the overall performance for ion thruster operation. To further analyze the experimental measurements, a framework was developed based on the magnetic field. A flux aligned coordinate system was developed to decouple the perpendicular and parallel plasma motion with respect to the magnetic field. This was done using the stream function and magnetic scalar potential. Magnetic formulae provided intuition on the field profiles dependence on magnet dimensions. The flux aligned coordinate system showed that the plasma was isopycnic along constant stream function values. This was used to develop an empirical relation suitable for estimating the spatial behavior and to determine the plasma volume and loss areas. The plasma geometry estimates were applied to a control volume

The Effect of Perceived Motivational Structure of Classroom on Achievement Behaviors

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Siavash Talepasand

2013-06-01

Full Text Available The aim of the study was to investigate the effect of perceived motivational structure of classroom on achievement behaviors (the choice of problem, effort, persistence in solving algorithm and flowchart problems. There were 45 high school male students (Mean age = 17 years old in the third grade of computer field in three classes. Classes were divided into two experimental and one control group. Instructional content was given in 10 sessions for 180 minutes. The variables of choice, effort, and persistence were collected by direct as-sessment method. A pre-test and post-test design was used. The Data were analyzed by using multivariate analysis of variance. Results indicated that mastery structure had positive effect on the amount of effort and persistence in solving algorithm and flowchart problems in comparison with control group. Mastery structure in comparison with performance structure increased the amount of effort in solving problems significantly. In addition, an interactive effect between previous achieve-ment and perceived structure of classroom was achieved in a mastery level. The amount of persistence in that of students with very weak previous achievement was more than students with average previous achievement. The find-ing of this study is compatible with the theory of achievement goal and illustrates that the mastery structure plays an effective role in forming achievement behaviors.

Examining the Dynamic Structure of Daily Internalizing and Externalizing Behavior at Multiple Levels of Analysis

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Aidan G.C. Wright

2015-12-01

Full Text Available Psychiatric diagnostic covariation suggests that the underlying structure of psychopathology is not one of circumscribed disorders. Quantitative modeling of individual differences in diagnostic patterns has uncovered several broad domains of mental disorder liability, of which the Internalizing and Externalizing spectra have garnered the greatest support. These dimensions have generally been estimated from lifetime or past-year comorbidity patters, which are distal from the covariation of symptoms and maladaptive behavior that ebb and flow in daily life. In this study, structural models are applied to daily diary data (Median = 94 days of maladaptive behaviors collected from a sample (N = 101 of individuals diagnosed with personality disorders. Using multilevel and unified structural equation modeling, between-person, within-person, and person-specific structures were estimated from 16 behaviors that are encompassed by the Internalizing and Externalizing spectra. At the between-person level (i.e., individual differences in average endorsement across days we found support for a two-factor Internalizing-Externalizing model, which exhibits significant associations with corresponding diagnostic spectra. At the within-person level (i.e., dynamic covariation among daily behavior pooled across individuals we found support for a more differentiated, four-factor, Negative Affect-Detachment-Hostility-Impulsivity structure. Finally, we demonstrate that the person-specific structures of associations between these four domains are highly idiosyncratic.

Examining the Dynamic Structure of Daily Internalizing and Externalizing Behavior at Multiple Levels of Analysis

Science.gov (United States)

Wright, Aidan G. C.; Beltz, Adriene M.; Gates, Kathleen M.; Molenaar, Peter C. M.; Simms, Leonard J.

2015-01-01

Psychiatric diagnostic covariation suggests that the underlying structure of psychopathology is not one of circumscribed disorders. Quantitative modeling of individual differences in diagnostic patterns has uncovered several broad domains of mental disorder liability, of which the Internalizing and Externalizing spectra have garnered the greatest support. These dimensions have generally been estimated from lifetime or past-year comorbidity patters, which are distal from the covariation of symptoms and maladaptive behavior that ebb and flow in daily life. In this study, structural models are applied to daily diary data (Median = 94 days) of maladaptive behaviors collected from a sample (N = 101) of individuals diagnosed with personality disorders (PDs). Using multilevel and unified structural equation modeling, between-person, within-person, and person-specific structures were estimated from 16 behaviors that are encompassed by the Internalizing and Externalizing spectra. At the between-person level (i.e., individual differences in average endorsement across days) we found support for a two-factor Internalizing–Externalizing model, which exhibits significant associations with corresponding diagnostic spectra. At the within-person level (i.e., dynamic covariation among daily behavior pooled across individuals) we found support for a more differentiated, four-factor, Negative Affect-Detachment-Hostility-Disinhibition structure. Finally, we demonstrate that the person-specific structures of associations between these four domains are highly idiosyncratic. PMID:26732546

Family structure and eating behavior disorders.

Science.gov (United States)

Mateos-Agut, Manuel; García-Alonso, Isabel; De la Gándara-Martín, Jesús J; Vegas-Miguel, María I; Sebastián-Vega, Carlota; Sanz-Cid, Beatriz; Martínez-Villares, Ana; Martín-Martínez, Esther

2014-01-01

The modern way of life, characterized by the cult of individualism, discredited authority, and a proliferation of points of view about reality, has modified family structure. This social structure imbues families and the way that its members become ill, in such a way that eating behavior disorders (EDs) have become a typically postmodern way of becoming ill. The aim is to understand the systemic structure and vulnerability of families by comparing 108 families with members who have ED to 108 families without pathology. A questionnaire administered by an interview with trained personnel was used. Families with ED have a different structure from the families in the control group. They have more psychiatric history and poor coping skills. The family hierarchy is not clearly defined and the leadership is diffuse, with strict and unpredictable rules, more intergenerational coalitions, and fewer alliances. The relationship between the parents is distant or confrontational, and their attitudes towards their children are complacent and selfish, with ambivalent and unaffectionate bonds. In the case of mothers, this is manifested by separation anxiety and dyadic dependence. Their expectations concerning their offspring are either very demanding and unrealistic, or indifferent, and there is less control of their behavior, in addition to poor organization of the family meals. The structural differences between the two groups of families seem to be important for the occurrence and maintenance of EDs, although they may not be the only cause. The results suggest strategies for clinical intervention in EDs.

Development of NONSTA code for the design and analysis of LMR high temperature structure

International Nuclear Information System (INIS)

Kim, Jong Bum; Lee, H. Y.; Yoo, B.

1999-02-01

Liquid metal reactor(LMR) operates at high temperature (500-550 dg C) and structural materials undergo complex deformation behavior like diffusion, dislocation glide, and dislocation climb due to high temperature environment. And the material life reduces rapidly due to the interaction of cavities created inside structural materials and high temperature fatigue cracks. Thus the establishment of high temperature structure analysis techniques is necessary for the reliability and safety evaluation of such structures. The objectives of this study are to develop NONSTA code as the subprogram of ABAQUS code adopting constitutive equations which can predict high temperature material behavior precisely and to build the systematic analysis procedures. The developed program was applied to the example problems such as the tensile analysis using exponential creep model and the repetitive tensile-compression analysis using Chaboche unified viscoplastic model. In addition, the problem of a plate with a center hole subjected to tensile load was solved to show the applicability of the program to multiaxial problem and the time dependent stress redistribution was observed. (Author). 40 refs., 2 tabs., 24 figs

The auxetic behavior of an expanded periodic cellular structure

Science.gov (United States)

Ciolan, Mihaela A.; Lache, Simona; Velea, Marian N.

2018-02-01

Within nowadays research, when it comes to lightweight sandwich panels, periodic cellular structures are considered real trendsetters. One of the most used type of core in producing sandwich panels is the honeycomb. However, due to its relatively high manufacturing cost, this structure has limited applications; therefore, research has been carried out in order to develop alternative solutions. An example in this sense is the ExpaAsym cellular structure, developed at the Transilvania University of Braşov; it represents a periodic cellular structure manufactured through a mechanically expansion process of a previously cut and perforated sheet material. The relative density of the structure was proven to be significantly lower than the one of the honeycomb. This gives a great advantage to the structure, due to the fact that when the internal angle A of the unit cell is 60°, after the mechanical expansion it results a hexagonal structure. The main objective of this paper is to estimate the in-plane Poisson ratios of the structure, in terms of its geometrical parameters. It is therefore analytically shown that for certain values of the geometric parameters, the in-plane Poisson ratios have negative values when the internal angle exceeds 90°, which determines its auxetic behavior.

Corrosion Behavior of Brazed Zinc-Coated Structured Sheet Metal

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A. Nikitin

2017-01-01

Full Text Available Arc brazing has, in comparison to arc welding, the advantage of less heat input while joining galvanized sheet metals. The evaporation of zinc is reduced in the areas adjacent to the joint and improved corrosion protection is achieved. In the automotive industry, lightweight design is a key technology against the background of the weight and environment protection. Structured sheet metals have higher stiffness compared to typical automobile sheet metals and therefore they can play an important role in lightweight structures. In the present paper, three arc brazing variants of galvanized structured sheet metals were validated in terms of the corrosion behavior. The standard gas metal arc brazing, the pulsed arc brazing, and the cold metal transfer (CMT® in combination with a pulsed cycle were investigated. In experimental climate change tests, the influence of the brazing processes on the corrosion behavior of galvanized structured sheet metals was investigated. After that, the corrosion behavior of brazed structured and flat sheet metals was compared. Because of the selected lap joint, the valuation of damage between sheet metals was conducted. The pulsed CMT brazing has been derived from the results as the best brazing method for the joining process of galvanized structured sheet metals.

Trust, Behavior, and High School Outcomes

Science.gov (United States)

Romero, Lisa S.

2015-01-01

Purpose: The purpose of this paper is to contribute to the literature on student trust and to examine the relationship between student trust, behavior, and academic outcomes in high school. It asks, first, does trust have a positive effect on high school outcomes? Second, does trust influence student behavior, exerting an indirect effect on…

Structured evaluation of rodent behavioral tests used in drug discovery research

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Anders eHånell

2014-07-01

Full Text Available A large variety of rodent behavioral tests are currently being used to evaluate traits such as sensory-motor function, social interactions, anxiety-like and depressive-like behavior, substance dependence and various forms of cognitive function. Most behavioral tests have an inherent complexity, and their use requires consideration of several aspects such as the source of motivation in the test, the interaction between experimenter and animal, sources of variability, the sensory modality required by the animal to solve the task as well as costs and required work effort. Of particular importance is a test’s validity because of its influence on the chance of successful translation of preclinical results to clinical settings. High validity may, however, have to be balanced against practical constraints and there are no behavioral tests with optimal characteristics. The design and development of new behavioral tests is therefore an ongoing effort and there are now well over one hundred tests described in the contemporary literature. Some of them are well established following extensive use, while others are novel and still unproven. The task of choosing a behavioral test for a particular project may therefore be daunting and the aim of the present review is to provide a structured way to evaluate rodent behavioral tests aimed at drug discovery research.

The Structure of Childhood Disruptive Behaviors

Science.gov (United States)

Martel, Michelle M.; Gremillion, Monica; Roberts, Bethan; von Eye, Alexander; Nigg, Joel T.

2010-01-01

Attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) frequently co-occur. Comorbidity of these 2 childhood disruptive behavior domains has not been satisfactorily explained at either a structural or etiological level. The current study evaluated a bifactor model, which allows for a "g" factor in addition to…

Factor Structure of Child Behavior Scale Scores in Peruvian Preschoolers

Science.gov (United States)

Meyer, Erin L.; Schaefer, Barbara A.; Soto, Cesar Merino; Simmons, Crystal S.; Anguiano, Rebecca; Brett, Jeremy; Holman, Alea; Martin, Justin F.; Hata, Heidi K.; Roberts, Kimberly J.; Mello, Zena R.; Worrell, Frank C.

2011-01-01

Behavior rating scales aid in the identification of problem behaviors, as well as the development of interventions to reduce such behavior. Although scores on many behavior rating scales have been validated in the United States, there have been few such studies in other cultural contexts. In this study, the structural validity of scores on a…

Assessment of thermo-mechanical behavior in CLAM steel first wall structures

International Nuclear Information System (INIS)

Liu Fubin; Yao Man

2012-01-01

Highlights: ► China Low Activation Martensitic steel (CLAM) as FW the structural material. ► The thermo-mechanical behavior of the FW was analyzed under the condition of normal ITER operation combined effect of plasma heat flux and neutron heating. ► The temperature dependence of the material physical properties of CLAM is summarized. - Abstract: The temperature and strain distributions of the mockup with distinct structural material (SS316L or China Low Activation Martensitic steel (CLAM)) in two-dimensional model were calculated and analyzed, based on a high heat flux (HHF) test recently reported with heat flux of 3.2 MW/m 2 . The calculated temperature and strain results in the first wall (FW), in which SS316L is as the structural material, showed good agreement with HHF test. By substituting CLAM steel for SS316L the contrast analysis indicates that the thermo-mechanical property for CLAM steel is better than that of SS316 at the same condition. Furthermore, the thermo-mechanical behavior of the FW was analyzed under the condition of normal ITER operation combined effect of plasma heat flux and neutron heating.

Assessment of thermo-mechanical behavior in CLAM steel first wall structures

Energy Technology Data Exchange (ETDEWEB)

Liu Fubin, E-mail: liufubin_1216@126.com [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, Liaoning (China); Yao Man, E-mail: yaoman@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, Liaoning (China)

2012-01-15

Highlights: Black-Right-Pointing-Pointer China Low Activation Martensitic steel (CLAM) as FW the structural material. Black-Right-Pointing-Pointer The thermo-mechanical behavior of the FW was analyzed under the condition of normal ITER operation combined effect of plasma heat flux and neutron heating. Black-Right-Pointing-Pointer The temperature dependence of the material physical properties of CLAM is summarized. - Abstract: The temperature and strain distributions of the mockup with distinct structural material (SS316L or China Low Activation Martensitic steel (CLAM)) in two-dimensional model were calculated and analyzed, based on a high heat flux (HHF) test recently reported with heat flux of 3.2 MW/m{sup 2}. The calculated temperature and strain results in the first wall (FW), in which SS316L is as the structural material, showed good agreement with HHF test. By substituting CLAM steel for SS316L the contrast analysis indicates that the thermo-mechanical property for CLAM steel is better than that of SS316 at the same condition. Furthermore, the thermo-mechanical behavior of the FW was analyzed under the condition of normal ITER operation combined effect of plasma heat flux and neutron heating.

A structural behavior study of rock caverns considering the effects of discontinuities

International Nuclear Information System (INIS)

Kim, Jhin Wung; Kim, Sun Hoon; Seo, Jeong Moon; Choi, Kyu Seop; Kim, Dae Hong; Lee, Kyung Jin; Choi, In Gil; Lee, Dong Yong

1990-06-01

The objective of this study is to understand the effects of discontinuities within rock masses on the structural behavior of underground rock caverns for radioactive waste disposal, and then develop a computer program for the structural analysis of rock caverns considering these effect of discontinuities. The behavior of rock masses, such as strength, deformation modes, ect., is very difficult to predict because discontinuities in the form of microcracks or joints are randomly distributed within rock masses. Discontinuties existing around the rock cavern for underground radioactive waste disposal may become the main transport pathways of radionuclides, and reduce the strength of rock masses eventually causing the rock cavern structure unstable. Therefore, a comprehensive understanding of the mechanical properties and behavior of discontinuous rock masses and an improvement of structural analysis methods are essential in order to understand the behavior of underground rock cavern structures properly in order to design safe and economic understanding the behavior of discontinuous rock masses is essential. Therfore, this study includes literature review on mechanical properties of and computational models for discontinuous rock masses, and on structures. Then, bases on the engineering judgement a suitable selection and slight modifications on computational models and analysis methods have been made before developing the structural analysis computer program for underground radioactive waste disposal structures. (author)

Structured parenting of toddlers at high versus low genetic risk: two pathways to child problems.

Science.gov (United States)

Leve, Leslie D; Harold, Gordon T; Ge, Xiaojia; Neiderhiser, Jenae M; Shaw, Daniel; Scaramella, Laura V; Reiss, David

2009-11-01

Little is known about how parenting might offset genetic risk to prevent the onset of child problems during toddlerhood. We used a prospective adoption design to separate genetic and environmental influences and test whether associations between structured parenting and toddler behavior problems were conditioned by genetic risk for psychopathology. The sample included 290 linked sets of adoptive families and birth mothers and 95 linked birth fathers. Genetic risk was assessed via birth mother and birth father psychopathology (anxiety, depression, antisociality, and drug use). Structured parenting was assessed via microsocial coding of adoptive mothers' behavior during a cleanup task. Toddler behavior problems were assessed with the Child Behavior Checklist. Controlling for temperamental risk at 9 months, there was an interaction between birth mother psychopathology and adoptive mothers' parenting on toddler behavior problems at 18 months. The interaction indicated two pathways to child problems: structured parenting was beneficial for toddlers at high genetic risk but was related to behavior problems for toddlers at low genetic risk. This crossover interaction pattern was replicated with birth father psychopathology as the index of genetic risk. The effects of structured parenting on toddler behavior problems varied as a function of genetic risk. Children at genetic risk might benefit from parenting interventions during toddlerhood that enhance structured parenting.

Highly ordered FEPT and FePd magnetic nano-structures: Correlated structural and magnetic studies

International Nuclear Information System (INIS)

Lukaszew, Rosa Alejandra; Cebollada, Alfonso; Clavero, Cesar; Garcia-Martin, Jose Miguel

2006-01-01

The micro-structure of epitaxial FePt and FePd films grown on MgO (0 0 1) substrates is correlated to their magnetic behavior. The FePd films exhibit high chemical ordering and perpendicular magnetic anisotropy. On the other hand FePt films exhibit low chemical ordering, with nano-grains oriented in two orthogonal directions, forcing the magnetization to remain in the plane of the films

Artificial neural networks in prediction of mechanical behavior of concrete at high temperature

International Nuclear Information System (INIS)

Mukherjee, A.; Nag Biswas, S.

1997-01-01

The behavior of concrete structures that are exposed to extreme thermo-mechanical loading is an issue of great importance in nuclear engineering. The mechanical behavior of concrete at high temperature is non-linear. The properties that regulate its response are highly temperature dependent and extremely complex. In addition, the constituent materials, e.g. aggregates, influence the response significantly. Attempts have been made to trace the stress-strain curve through mathematical models and rheological models. However, it has been difficult to include all the contributing factors in the mathematical model. This paper examines a new programming paradigm, artificial neural networks, for the problem. Implementing a feedforward network and backpropagation algorithm the stress-strain relationship of the material is captured. The neural networks for the prediction of uniaxial behavior of concrete at high temperature has been presented here. The results of the present investigation are very encouraging. (orig.)

The effects of poaching and habitat structure on anti-predator behavioral strategies: A guanaco population in a high cold desert as case study.

Science.gov (United States)

Cappa, Flavio; Campos, Valeria; Giannoni, Stella; Andino, Natalia

2017-01-01

The effects of poaching on wildlife have been widely studied in conservation biology and can be heterogeneous, particularly on ungulates. These effects can be estimated through different methodologies whose use depends on several conditions such as Flight-initiation distance (FID). Our objectives were: 1- to evaluate whether poaching affects the FID and group structure of a guanaco (Lama guanicoe) population in a high cold desert in San Juan (Argentina); 2- to assess whether habitat structure (slope and vegetation cover) influences FID and group structure in this population. The study area included a site with poaching (unprotected area), and a site without poaching (protected area). We recorded 100 groups of guanacos: 70 in the protected and 30 in the unprotected area. FID and group size were greater in the unprotected than in the protected area, whereas proportions of group categories (with offspring, without offspring and solitary) were similar between areas. Besides, in relation to habitat structure, FID increased when vegetation cover decreased. On the other hand, FID and group size were not affected by slope. Our study shows that guanacos respond to poaching pressure as do other ungulate species, and that other factors such as vegetation cover also affect this behavior. Managers should be aware when interpreting FID due to its relation to habitat structure; the guanaco appears to assume greater risk (lower FID) in areas with high vegetation cover.

A development report on the inelastic analysis program for the high temperature structures

International Nuclear Information System (INIS)

Kim, Jong Bum; Lee, H. Y.; Lee, J. H.

2001-04-01

LMR high temperature structures such as reactor vessel and reactor internal structures are subject to high temperature operating loads thus they can undergo damage due to creep, creep-fatigue, and ratcheting behavior. In this project, NONSTA-EP program implementing combined isotropic and kinematic hardening behavior and NONSTA-VP program implementing Chaboche model, which is so called viscoplasticity model, have been developed and have been continuously improved. In the year of 2000, NONSTA-OW program implementing Ohno-Wang model which can simulate progressive plasticity (that is ratcheting) more precisely compared to other models. One of the characteristics of inelastic constitutive equations is to have various numbers of material parameters to simulate complex material behaviors realistically and it is very important to obtain these material parameters. In this project, the improved method to obtain these material parameters has been studied with the optimal technique and by conducting material characteristic tests under high temperature conditions. The feasibility of the developed program with Ohno-Wang model, which contains 9 isotropic constitutive equations, has been studied through the example problem

Nonlinear analysis of reinforced concrete structures subjected to high temperature and external load

International Nuclear Information System (INIS)

Sugawara, Y.; Goto, M.; Saito, K.; Suzuki, N.; Muto, A.; Ueda, M.

1993-01-01

A quarter of a century has passed since the finite element method was first applied to nonlinear problems concerning reinforced concrete structures, and the reliability of the analysis at ordinary temperature has been enhanced accordingly. By contrast, few studies have tried to deal with the nonlinear behavior of reinforced concrete structures subjected to high temperature and external loads simultaneously. It is generally known that the mechanical properties of concrete and steel are affected greatly by temperature. Therefore, in order to analyze the nonlinear behavior of reinforced concrete subjected to external loads at high temperature, it is necessary to construct constitutive models of the materials reflecting the influence of temperature. In this study, constitutive models of concrete and reinforcement that can express decreases in strength and stiffness at high temperature have been developed. A two-dimensional nonlinear finite element analysis program has been developed by use of these material models. The behavior of reinforced concrete beams subjected simultaneously to high temperature and shear forces were simulated using the developed analytical method. The results of the simulation agreed well with the experimental results, evidencing the validity of the developed material models and the finite element analysis program

Preschool externalizing behavior predicts gender-specific variation in adolescent neural structure.

Directory of Open Access Journals (Sweden)

Jessica Z K Caldwell

Full Text Available Dysfunction in the prefrontal cortex, amygdala, and hippocampus is believed to underlie the development of much psychopathology. However, to date only limited longitudinal data relate early behavior with neural structure later in life. Our objective was to examine the relationship of early life externalizing behavior with adolescent brain structure. We report here the first longitudinal study linking externalizing behavior during preschool to brain structure during adolescence. We examined the relationship of preschool externalizing behavior with amygdala, hippocampus, and prefrontal cortex volumes at age 15 years in a community sample of 76 adolescents followed longitudinally since their mothers' pregnancy. A significant gender by externalizing behavior interaction revealed that males-but not females-with greater early childhood externalizing behavior had smaller amygdala volumes at adolescence (t = 2.33, p = .023. No significant results were found for the hippocampus or the prefrontal cortex. Greater early externalizing behavior also related to smaller volume of a cluster including the angular gyrus and tempoparietal junction across genders. Results were not attributable to the impact of preschool anxiety, preschool maternal stress, school-age internalizing or externalizing behaviors, or adolescent substance use. These findings demonstrate a novel, gender-specific relationship between early-childhood externalizing behavior and adolescent amygdala volume, as well as a cross-gender result for the angular gyrus and tempoparietal junction.

X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press

International Nuclear Information System (INIS)

Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Shen, Guoyin; Shibazaki, Yuki; Wang, Yanbin

2015-01-01

Several X-ray techniques for studying structure, elastic properties, viscosity, and immiscibility of liquids at high pressures have been integrated using a Paris-Edinburgh press at the 16-BM-B beamline of the Advanced Photon Source. Here, we report the development of X-ray imaging techniques suitable for studying behavior of liquids at high pressures and high temperatures. White X-ray radiography allows for imaging phase separation and immiscibility of melts at high pressures, identified not only by density contrast but also by phase contrast imaging in particular for low density contrast liquids such as silicate and carbonate melts. In addition, ultrafast X-ray imaging, at frame rates up to ∼10 5 frames/second (fps) in air and up to ∼10 4 fps in Paris-Edinburgh press, enables us to investigate dynamics of liquids at high pressures. Very low viscosities of melts similar to that of water can be reliably measured. These high-pressure X-ray imaging techniques provide useful tools for understanding behavior of liquids or melts at high pressures and high temperatures

X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press

Energy Technology Data Exchange (ETDEWEB)

Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Shen, Guoyin [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, 9700 S. Cass Ave., Argonne, Illinois 60439 (United States); Shibazaki, Yuki [Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki aza Aoba 6-3, Aoba-ku, Sendai 980-8578 (Japan); Wang, Yanbin [GeoSoilEnviroCARS, Center for Advanced Radiation Sources, The University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States)

2015-07-15

Several X-ray techniques for studying structure, elastic properties, viscosity, and immiscibility of liquids at high pressures have been integrated using a Paris-Edinburgh press at the 16-BM-B beamline of the Advanced Photon Source. Here, we report the development of X-ray imaging techniques suitable for studying behavior of liquids at high pressures and high temperatures. White X-ray radiography allows for imaging phase separation and immiscibility of melts at high pressures, identified not only by density contrast but also by phase contrast imaging in particular for low density contrast liquids such as silicate and carbonate melts. In addition, ultrafast X-ray imaging, at frame rates up to ∼10{sup 5} frames/second (fps) in air and up to ∼10{sup 4} fps in Paris-Edinburgh press, enables us to investigate dynamics of liquids at high pressures. Very low viscosities of melts similar to that of water can be reliably measured. These high-pressure X-ray imaging techniques provide useful tools for understanding behavior of liquids or melts at high pressures and high temperatures.

Problematic Gaming Behavior Among Finnish Junior High School Students: Relation to Socio-Demographics and Gaming Behavior Characteristics.

Science.gov (United States)

Männikkö, Niko; Ruotsalainen, Heidi; Demetrovics, Zsolt; Lopez-Fernandez, Olatz; Myllymäki, Laura; Miettunen, Jouko; Kääriäinen, Maria

2017-09-14

Multiplatform digital media use and gaming have been increased in recent years. The aim of this study was to examine associations between sociodemographics and digital gaming behavior characteristics (i.e., gaming time, medium, and genres) with problematic gaming behavior in adolescents. A convenience sample of Finnish junior high school students (n = 560; mean age 14 years, ranging from 12 to 16 years) participated in the cross-sectional survey, of which, 83% (n = 465) reported having played digital games regularly. Sociodemographic data, different forms of digital media use, gaming behavior characteristics and problematic gaming behavior was assessed. Study participants spent on average one hour per day playing digital games; casual games (23.9%), shooting games (19.8%), and sport games (12.9%), were the most popular games among participants. By using regression analysis, a blended family structure and gaming time related positively to problematic gaming behavior. Preferences for game genres such as solo, Massively Multiplayer Online Role-Playing and strategy-management games were also positively associated with problematic use of digital games. These findings provide knowledge that can be utilized in the prevention of the possible negative consequences of digital gaming.

Ductile fracture behavior of cast structure containing voids

Energy Technology Data Exchange (ETDEWEB)

Gilles, Ph.; Migne, C. [FRAMATOME ANP, 92 - Paris-La-Defence (France); Chapuliot, S. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. de Mecanique et de Technologie

2001-07-01

In pressurized water reactors, the primary loop contains cast-piping components made of duplex stainless steel. Due to the presence of ferrite, such steels are susceptible to thermal aging embrittlement, which decrease their fracture resistance. The cast process induces shrinkage cavities, therefore all these components are submitted to liquid penetrant examination and all surface defects are repaired. EDF, CEA and Framatome have conducted experimental and analytical analysis of fatigue and fracture behavior of aged cast stainless steel structures containing shrinkage cavities. The present study considers only ductile tearing and is based on specimen test results and a fracture mechanics model of the interaction between shrinkage cavities. The experimental results presented here show that large groups of shrinkage cavities have almost no influence on the global behavior of the structure. Only for the specimen with the largest reduction of area, a significant reduction of strength has been registered. Using elementary fracture mechanics models, it has been evidenced that failure mechanism of structures containing shrinkage cavities consists in 3 phases: local initiation, macro-crack formation by coalescence and failure by crack instability or collapse depending if J resistance is low or not. No significant changes in global behavior appear in the first phase. (A.C.)

Ductile fracture behavior of cast structure containing voids

International Nuclear Information System (INIS)

Gilles, Ph.; Migne, C.; Chapuliot, S.

2001-01-01

In pressurized water reactors, the primary loop contains cast-piping components made of duplex stainless steel. Due to the presence of ferrite, such steels are susceptible to thermal aging embrittlement, which decrease their fracture resistance. The cast process induces shrinkage cavities, therefore all these components are submitted to liquid penetrant examination and all surface defects are repaired. EDF, CEA and Framatome have conducted experimental and analytical analysis of fatigue and fracture behavior of aged cast stainless steel structures containing shrinkage cavities. The present study considers only ductile tearing and is based on specimen test results and a fracture mechanics model of the interaction between shrinkage cavities. The experimental results presented here show that large groups of shrinkage cavities have almost no influence on the global behavior of the structure. Only for the specimen with the largest reduction of area, a significant reduction of strength has been registered. Using elementary fracture mechanics models, it has been evidenced that failure mechanism of structures containing shrinkage cavities consists in 3 phases: local initiation, macro-crack formation by coalescence and failure by crack instability or collapse depending if J resistance is low or not. No significant changes in global behavior appear in the first phase. (A.C.)

DYNAMIC BEHAVIOR OF TWO-SPAN CONTINUOUS CONCRETE BRIDGES UNDER MOVING OF HIGH-SPEED TRAINS

Directory of Open Access Journals (Sweden)

O. H. Marinichenko

2017-10-01

Full Text Available Purpose. The scientific work provides a comparison of the results of the movement of a high-speed passenger train across the bridge, obtained as a result of finite element modeling in the SAP2000 software package, and real tests of a double-span concrete railway bridge. Analysis of the rigid characteristics of flying structures. Methodology.The numerical method presented in this study shows valid results concerning the dynamic analysis of the behavior of bridges in conditions of high-speed train traffic. The factors influencing the dynamic behavior of bridges under moving loads, the influence of design parameters and rolling stock, as well as the interaction of the train and spans are determined. The system was used in the form of moving concentrated forces simulating the axes of the train. Findings. Maximum movements and accelerations were obtained as a result of the dynamic calculation for different speeds of the train and compared with practical tests. The correctness of the model of a span structure with regard to continuous ferroconcrete spans was verified. Originality. Within the framework of the work, the latest test results were used, including those with speeds calculated on the prospect of rail passenger traffic. For these tests, a model of a span structure was developed. Practical value. The results of the research can be used to plan the introduction of high-speed train traffic on existing and planned flying structures of reinforced concrete bridges. An approach to the design of span structures that will be effective when passing high-speed passenger trains is implemented.

Gang Membership, School Violence, and the Mediating Effects of Risk and Protective Behaviors in California High Schools

Science.gov (United States)

Estrada, Joey Nuñez, Jr.; Gilreath, Tamika D.; Astor, Ron Avi; Benbenishty, Rami

2014-01-01

There is insufficient empirical evidence exploring associations between gang membership and school violence behaviors. Using a sample of 272,863 high school students, this study employs a structural equation model to examine how school risk and protective behaviors and attitudes mediate effects of gang members' involvement with school violence…

High frequency flow-structural interaction in dense subsonic fluids

Science.gov (United States)

Liu, Baw-Lin; Ofarrell, J. M.

1995-01-01

Prediction of the detailed dynamic behavior in rocket propellant feed systems and engines and other such high-energy fluid systems requires precise analysis to assure structural performance. Designs sometimes require placement of bluff bodies in a flow passage. Additionally, there are flexibilities in ducts, liners, and piping systems. A design handbook and interactive data base have been developed for assessing flow/structural interactions to be used as a tool in design and development, to evaluate applicable geometries before problems develop, or to eliminate or minimize problems with existing hardware. This is a compilation of analytical/empirical data and techniques to evaluate detailed dynamic characteristics of both the fluid and structures. These techniques have direct applicability to rocket engine internal flow passages, hot gas drive systems, and vehicle propellant feed systems. Organization of the handbook is by basic geometries for estimating Strouhal numbers, added mass effects, mode shapes for various end constraints, critical onset flow conditions, and possible structural response amplitudes. Emphasis is on dense fluids and high structural loading potential for fatigue at low subsonic flow speeds where high-frequency excitations are possible. Avoidance and corrective measure illustrations are presented together with analytical curve fits for predictions compiled from a comprehensive data base.

Oxidation behavior of TD-NiCr in a dynamic high temperature environment

Science.gov (United States)

Tenney, D. R.; Young, C. T.; Herring, H. W.

1974-01-01

The oxidation behavior of TD-NiCr has been studied in static and high-speed flowing air environments at 1100 and 1200 C. It has been found that the stable oxide morphologies formed on the specimens exposed to the static and dynamic environments were markedly different. The faceted crystal morphology characteristic of static oxidation was found to be unstable under high-temperature, high-speed flow conditions and was quickly replaced by a porous NiO 'mushroom' type structure. Also, it was found that the rate of formation of CrO3 from Cr2O3 was greatly enhanced by high gas velocity conditions. The stability of Cr2-O3 was found to be greatly improved by the presence of an outer NiO layer, even though the NiO layer was very porous. An oxidation model is proposed to explain the observed microstructures and overall oxidation behavior of TD-NiCr alloys.

Examining Relationships among Enabling School Structures, Academic Optimism and Organizational Citizenship Behaviors

Science.gov (United States)

Messick, Penelope Pope

2012-01-01

This study examined the relationships among enabling school structures, academic optimism, and organizational citizenship behaviors. Additionally, it sought to determine if academic optimism served as a mediator between enabling school structures and organizational citizenship behaviors. Three existing survey instruments, previously tested for…

Dissociation behavior of methane--ethane mixed gas hydrate coexisting structures I and II.

Science.gov (United States)

Kida, Masato; Jin, Yusuke; Takahashi, Nobuo; Nagao, Jiro; Narita, Hideo

2010-09-09

Dissociation behavior of methane-ethane mixed gas hydrate coexisting structures I and II at constant temperatures less than 223 K was studied with use of powder X-ray diffraction and solid-state (13)C NMR techniques. The diffraction patterns at temperatures less than 203 K showed both structures I and II simultaneously convert to Ih during the dissociation, but the diffraction pattern at temperatures greater than 208 K showed different dissociation behavior between structures I and II. Although the diffraction peaks from structure II decreased during measurement at constant temperatures greater than 208 K, those from structure I increased at the initial step of dissociation and then disappeared. This anomalous behavior of the methane-ethane mixed gas hydrate coexisting structures I and II was examined by using the (13)C NMR technique. The (13)C NMR spectra revealed that the anomalous behavior results from the formation of ethane-rich structure I. The structure I hydrate formation was associated with the dissociation rate of the initial methane-ethane mixed gas hydrate.

High-rate operant behavior in two mouse strains: a response-bout analysis.

Science.gov (United States)

Johnson, Joshua E; Pesek, Erin F; Newland, M Christopher

2009-06-01

Operant behavior sometimes occurs in bouts characterized by an initiation rate, within-bout response rate, and bout length. The generality of this structure was tested using high-rate nose-poking in mice. Reinforcement of short interresponse times produced high response rates while a random-interval schedule held reinforcement rates constant. BALB/c mice produced bouts that were more frequent, longer, and contained a higher within-bout rate of responding (nine nose-pokes/s) than did the C57BL/6 mice (five nose-pokes/s). Adding a running wheel decreased total nose-pokes and bout length, and increased bout-initiation rate. Free-feeding reduced nose-poking by decreasing bout-initiation rate. Photoperiod reversal decreased bout-initiation rate but not total nose-poke rate. Despite strain differences in bout structure, both strains responded similarly to the interventions. The three bout measures were correlated with overall rate but not with each other. Log-survival analyses provided independent descriptors of the structure of high-rate responding in these two strains.

Thermal behavior of spatial structures under solar irradiation

International Nuclear Information System (INIS)

Liu, Hongbo; Liao, Xiangwei; Chen, Zhihua; Zhang, Qian

2015-01-01

The temperature, particularly the non-uniform temperature under solar irradiation, is the main load for large-span steel structures. Due the shortage of in-site temperature test in previous studies, an in-site test was conducted on the large-span steel structures under solar irradiation, which was covered by glass roof and light roof, to gain insight into the temperature distribution of steel members under glass roof or light roof. A numerical method also was presented and verified to forecast the temperature of steel member under glass roof or light roof. Based on the on-site measurement and numerical analyses conducted, the following conclusions were obtained: 1) a remarkable temperature difference exists between the steel member under glass roof and that under light roof, 2) solar irradiation has a significant effect on the temperature distribution and thermal behavior of large-span spatial structures, 3) negative thermal load is the controlling factor for member stress, and the positive thermal load is the controlling factor for nodal displacement. - Highlights: • Temperature was measured for a steel structures under glass roof and light roof. • Temperature simulation method was presented and verified. • The thermal behavior of steel structures under glass or light roof was presented

Influence of structural disorder on low-temperature behavior of penetration depth in electron-doped high-TC thin films

International Nuclear Information System (INIS)

Lanfredi, A.J.C.; Sergeenkov, S.; Araujo-Moreira, F.M.

2006-01-01

To probe the influence of structural disorder on low-temperature behavior of magnetic penetration depth, λ(T), in electron-doped high-T C superconductors, a comparative study of high-quality Pr 1.85 Ce 0.15 CuO 4 (PCCO) and Sm 1.85 Ce 0.15 CuO 4 (SCCO) thin films is presented. The λ(T) profiles are extracted from conductance-voltage data using a highly-sensitive home-made mutual-inductance technique. The obtained results confirm a d-wave pairing mechanism in both samples (with nodal gap parameter Δ 0 /k B T C =2.0 and 2.1 for PCCO and SCCO films, respectively), substantially modified by impurity scattering (which is more noticeable in less homogeneous SCCO films) at the lowest temperatures. More precisely, Δλ(T)=λ(T)-λ(0) is found to follow the Goldenfeld-Hirschfeld interpolation formulae Δλ(T)/λ(0)=AT 2 /(T+T 0 ) with T 0 =ln(2)k B Γ 1/2 Δ 0 1/2 being the crossover temperature which demarcates pure and impure scattering processes (T 0 /T C =0.13 and 0.26 for PCCO and SCCO films, respectively). The value of the extracted impurity scattering rate Γ correlates with the quality of our samples and is found to be much higher in less homogeneous films with lower T C

High pressure structural phase transitions of TiO2 nanomaterials

International Nuclear Information System (INIS)

Li Quan-Jun; Liu Bing-Bing

2016-01-01

Recently, the high pressure study on the TiO 2 nanomaterials has attracted considerable attention due to the typical crystal structure and the fascinating properties of TiO 2 with nanoscale sizes. In this paper, we briefly review the recent progress in the high pressure phase transitions of TiO 2 nanomaterials. We discuss the size effects and morphology effects on the high pressure phase transitions of TiO 2 nanomaterials with different particle sizes, morphologies, and microstructures. Several typical pressure-induced structural phase transitions in TiO 2 nanomaterials are presented, including size-dependent phase transition selectivity in nanoparticles, morphology-tuned phase transition in nanowires, nanosheets, and nanoporous materials, and pressure-induced amorphization (PIA) and polyamorphism in ultrafine nanoparticles and TiO 2 -B nanoribbons. Various TiO 2 nanostructural materials with high pressure structures are prepared successfully by high pressure treatment of the corresponding crystal nanomaterials, such as amorphous TiO 2 nanoribbons, α -PbO 2 -type TiO 2 nanowires, nanosheets, and nanoporous materials. These studies suggest that the high pressure phase transitions of TiO 2 nanomaterials depend on the nanosize, morphology, interface energy, and microstructure. The diversity of high pressure behaviors of TiO 2 nanomaterials provides a new insight into the properties of nanomaterials, and paves a way for preparing new nanomaterials with novel high pressure structures and properties for various applications. (topical review)

Structural behavior of Tl-exchanged natrolite at high pressure depending on the composition of pressure-transmitting medium

Science.gov (United States)

Seryotkin, Yu. V.; Bakakin, V. V.; Likhacheva, A. Yu.; Dementiev, S. N.; Rashchenko, S. V.

2017-10-01

The structural evolution of Tl-exchanged natrolite with idealized formula Tl2[Al2Si3O10]·2H2O, compressed in penetrating (water:ethanol 1:1) and non-penetrating (paraffin) media, was studied up to 4 GPa. The presence of Tl+ with non-bonded electron lone pairs, which can be either stereo-chemically active or passive, determines distinctive features of the high-pressure behavior of the Tl-form. The effective volume of assemblages Tl+(O,H2O) n depends on the E-pairs activity: single-sided coordination correlates with smaller volumes. At ambient conditions, there are two types of Tl positions, only one of them having a nearly single-sided coordination as a characteristic of stereo-activity of the Tl+ E pair. Upon the compression in paraffin, a phase transition occurs: a 5% volume contraction of flexible natrolite framework is accompanied by the conversion of all the Tl+ cations into stereo-chemically active state with a single-sided coordination. This effect requires the reconstruction of all the extra-framework subsystems with the inversion of the cation and H2O positions. The compression in water-containing medium leads to the increase of H2O content up to three molecules pfu through the filling of partly vacant positions. This hinders a single-sided coordination of Tl ions and preserves the configuration of their ion-molecular subsystem. It is likely that the extra-framework subsystem is responsible for the super-structure modulation.

Creep deformation and rupture behavior of type 304/308 stainless steel structural weldments

International Nuclear Information System (INIS)

McAfee, W.J.; Richardson, M.; Sartory, W.K.

1977-01-01

The creep deformation and rupture of type 304/308 stainless steel structural weldments at 593 0 C (1100 0 F) was experimentally investigated to study the comparative behavior of the base metal and weld metal constituents. The tests were conducted in support of ORNL's program to develop high-temperature structural design methods applicable to liquid-metal fast breeder reactor (LMFBR) system components that operate in the creep range. The specimens used were thin-walled, right circular cylinders capped with either flat or hemispherical heads and tested under internal gas pressure. Circumferential welds were located in different regions of the cylinder or head and, with one exception, were geometrically duplicated by all base metal regions in companion specimens. Results are presented on the comparative deformation and rupture behavior of selected points in the base metal and weldment regions of the different specimens and on the overall surface strains for selected specimens

Homogenization-based topology optimization for high-resolution manufacturable micro-structures

DEFF Research Database (Denmark)

Groen, Jeroen Peter; Sigmund, Ole

2018-01-01

This paper presents a projection method to obtain high-resolution, manufacturable structures from efficient and coarse-scale, homogenization-based topology optimization results. The presented approach bridges coarse and fine scale, such that the complex periodic micro-structures can be represented...... by a smooth and continuous lattice on the fine mesh. A heuristic methodology allows control of the projected topology, such that a minimum length-scale on both solid and void features is ensured in the final result. Numerical examples show excellent behavior of the method, where performances of the projected...

[The structure of aggression of the patients with paranoid schizophrenia and compensatory behavioral trends].

Science.gov (United States)

Reverchuk, I V; Khudyakova, Yu Yu

To study the structure of aggression of the patients with paranoid schizophrenia depending on sex and illness duration. 102 patients with paranoid schizophrenia and 101 healthy people, aged from 18 to 64 years, were examined. Quantitative indicators of cognitive, emotional, and behavioral components of aggression were measured using the Buss-Perry questionnaire. The projective Hand-test was administered to assess aggressive behavioral tendencies and inclinations to aggressive behavior. The authors identified the dissociated structure of aggressiveness in patients with paranoid schizophrenia that manifested with dissociated cognitive, emotional, and behavioral components. The specifics of the structure of aggression and compensatory behavioral trends are described.

Modeling and analysis of aging behavior of concrete structures in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Rashid, J.Y.R.; James, R.J.; Dunham, R.S. [ANATECH (United States)

2011-07-01

As nuclear power plants approach the end of their original design life and begin to transition to the life extension phase, consideration has to be given to the effects of structural aging when evaluating the extended operation of reinforced or pre-stressed concrete structures. The behavior of concrete is highly nonlinear, having low tensile strength, shear stiffness and strength that depend on crack widths, and a confinement-dependent compressive elasto-plasticity. A concrete material model is described having the appropriate capabilities required for evaluating structural aging. The model treats reinforced concrete as a three-phase composite: plain concrete material as a three-dimensional continuum phase, steel reinforcement (rebar) as a uni-directional phase, and a rebar-concrete interaction phase. Structural aging is defined as the combined effects of time dependent material properties degradation and service induced changes in loading and operational conditions. Three broad categories of structural aging, and the interaction between them, are considered: 1) Aging effects due to expected time dependent changes in material properties, 2) Aging effects due to unexpected time dependent material degradation, and 3) Aging effects due to operational environment and loading. Example analyses are presented which illustrate the value of using advanced modeling and simulation in evaluating expected and unusual structural behavior. This is particularly important for safety structures that are approaching the end of their design life and are facing the prospect of re-licensing for extended operation

Sexting behaviors among young Hispanic women: incidence and association with other high-risk sexual behaviors.

Science.gov (United States)

Ferguson, Christopher J

2011-09-01

Several legal cases in the United States in which adolescents were charged with child pornography distribution after sharing nude photographs of themselves with romantic partners or others have highlighted the issue of sexting behaviors among youth. Although policy makers, mental health workers, educators and parents have all expressed concern regarding the potential harm of sexting behaviors, little to no research has examined this phenomenon empirically. The current study presents some preliminary data on the incidence of sexting behavior and associated high risk sexual behaviors in a sample of 207 predominantly Hispanic young women age 16-25. Approximately 20% of young women reported engaging in sexting behavior. Sexting behaviors were not associated with most other high-risk sexual behaviors, but were slightly more common in women who found sex to be highly pleasurable or who displayed histrionic personality traits.

High-energy behavior of non-Abelian gauge theories

International Nuclear Information System (INIS)

Nieh, H.T.; Yao, Y.

1976-01-01

This paper is a detailed account of a study in perturbation theory of the high-energy behavior of non-Abelian gauge theories. The fermion-fermion scattering amplitude is calculated up to sixth order in the coupling constant in the high-energy limit s → infinity with fixed t, in the approximation of keeping only the leading logarithmic terms. Results indicate that the high-energy behavior of non-Abelian gauge theories are complicated, and quite different from the known behaviors of other field theories studied so far

Anharmonic behavior and structural phase transition in Yb2O3

Directory of Open Access Journals (Sweden)

Sugandha Dogra Pandey

2013-12-01

Full Text Available The investigation of structural phase transition and anharmonic behavior of Yb2O3 has been carried out by high-pressure and temperature dependent Raman scattering studies respectively. In situ Raman studies under high pressure were carried out in a diamond anvil cell at room temperature which indicate a structural transition from cubic to hexagonal phase at and above 20.6 GPa. In the decompression cycle, Yb2O3 retained its high pressure phase. We have observed a Stark line in the Raman spectra at 337.5 cm−1 which arises from the electronic transition between 2F5/2 and 2F7/2 multiplates of Yb3+ (4f13 levels. These were followed by temperature dependent Raman studies in the range of 80–440 K, which show an unusual mode hardening with increasing temperature. The hardening of the most dominant mode (Tg + Ag was analyzed in light of the theory of anharmonic phonon-phonon interaction and thermal expansion of the lattice. Using the mode Grüneisen parameter obtained from high pressure Raman measurements; we have calculated total anharmonicity of the Tg + Ag mode from the temperature dependent Raman data.

A phenotypic structure and neural correlates of compulsive behaviors in adolescents.

Science.gov (United States)

Montigny, Chantale; Castellanos-Ryan, Natalie; Whelan, Robert; Banaschewski, Tobias; Barker, Gareth J; Büchel, Christian; Gallinat, Jürgen; Flor, Herta; Mann, Karl; Paillère-Martinot, Marie-Laure; Nees, Frauke; Lathrop, Mark; Loth, Eva; Paus, Tomas; Pausova, Zdenka; Rietschel, Marcella; Schumann, Gunter; Smolka, Michael N; Struve, Maren; Robbins, Trevor W; Garavan, Hugh; Conrod, Patricia J

2013-01-01

A compulsivity spectrum has been hypothesized to exist across Obsessive-Compulsive disorder (OCD), Eating Disorders (ED), substance abuse (SA) and binge-drinking (BD). The objective was to examine the validity of this compulsivity spectrum, and differentiate it from an externalizing behaviors dimension, but also to look at hypothesized personality and neural correlates. A community-sample of adolescents (N=1938; mean age 14.5 years), and their parents were recruited via high-schools in 8 European study sites. Data on adolescents' psychiatric symptoms, DSM diagnoses (DAWBA) and substance use behaviors (AUDIT and ESPAD) were collected through adolescent- and parent-reported questionnaires and interviews. The phenotypic structure of compulsive behaviors was then tested using structural equation modeling. The model was validated using personality variables (NEO-FFI and TCI), and Voxel-Based Morphometry (VBM) analysis. Compulsivity symptoms best fit a higher-order two factor model, with ED and OCD loading onto a compulsivity factor, and BD and SA loading onto an externalizing factor, composed also of ADHD and conduct disorder symptoms. The compulsivity construct correlated with neuroticism (r=0.638; p ≤ 0.001), conscientiousness (r=0.171; p ≤ 0.001), and brain gray matter volume in left and right orbitofrontal cortex, right ventral striatum and right dorsolateral prefrontal cortex. The externalizing factor correlated with extraversion (r=0.201; p ≤ 0.001), novelty-seeking (r=0.451; p ≤ 0.001), and negatively with gray matter volume in the left inferior and middle frontal gyri. Results suggest that a compulsivity spectrum exists in an adolescent, preclinical sample and accounts for variance in both OCD and ED, but not substance-related behaviors, and can be differentiated from an externalizing spectrum.

Characterization of Anisotropic Behavior for High Grade Pipes

Science.gov (United States)

Yang, Kun; Huo, Chunyong; Ji, Lingkang; Li, Yang; Zhang, Jiming; Ma, Qiurong

With the developing requirement of nature gas, the property needs of steel for pipe line are higher and higher, especially in strength and toughness. It is necessary to improve the steel grade in order to ensure economic demand and safety. However, with the rise of steel grade, the differences on properties in different orientations (anisotropic behaviors) become more and more obvious after the process of hot rolling, which may affect the prediction of fracture for the pipes seriously (Thinking of isotropic mechanical properties for material in traditional predict way). In order to get the reason for anisotropic mechanics, a series of tests are carried out for high grade steel pipes, including not only mechanical properties but also microstructures. Result indicates that there are obviously anisotropic behaviors for high grade steel pipes in two orientations (rolling orientation and transverse orientation). Strength is better in T orientation because Rm is higher and Rt 0.5 rises more in T orientation, and toughness is better in L orientation because of the higher Akv and SA in L orientation under a same temperature. Banded structures are formed in T orientation, and the spatial distribution of inclusion and precipitated phases are different in T, L and S orientation. The anisotropic arrangement for the matrix in space (banded structures), which is formed after the process of hot rolling, may affect the mechanical properties in different orientation. Moreover, the elasticity modulus of particles is different from the elasticity modulus of matrix, deformation between particles and matrix may cause stress concentration, and damage forms in this place. Because of the different distribution of particles in space, the level of damage is anisotropic in different orientations, and the anisotropic mechanical properties occur finally. Therefore, the anisotropic mechanical properties are determined by the anisotropic microstructures, both the anisotropic of matrix and the

A social work study high-risk behavior among teenagers

Directory of Open Access Journals (Sweden)

Mohammad Reza Iravani

2012-01-01

Full Text Available Teenagers are believed the people who are supposed to build the world's future. High-risk behaviors such as addiction to drugs, smoking cigarettes, sex, etc. could significantly hurts teenagers and there must be some supporting programs to reduce these issues as much as possible. This paper performs an empirical investigation to study the different factors influencing high- risk behavior among teenagers who live in a city of Esfahan, Iran. The proposed study designs a questionnaire and distribute between two groups of female and male teenagers. The results indicate that while there is a meaningful relationship between high-risk behaviors and average high school marks among male students there is no meaningful relationship between high-risk behaviors and high school grades among female students. The results also indicate that there is a meaningful difference between gender and high-risk behavior. The season of birth for female and male students is another important factor for having high-risk behaviors. While the order of birth plays an important role among male students, the order of birth is not an important factor among female teenagers. Finally, the results indicate that teenagers' parental financial affordability plays a vital role on both female and male teenagers.

Behavioral Logistics - Analysis of behavioral routines and governance structures in the interorganizational maritime transport chain

Directory of Open Access Journals (Sweden)

2010-09-01

Full Text Available The strong improvements in information and communication systems as well as better transshipment technologies provide the platform for more efficient transport within interorganizational transport chains. Nevertheless these technologies do not automatically optimize systems based on routines and behavioral patterns, established over the last decades. Logisticians - in theory and practice - have to consider the field of behavioral science to describe and analyse transport problems regarding to involved actors' strategic behavior and social embeddedness, too. The objective of this paper is to illustrate behavioral aspects of supposed technical problems in interorganizational transport chains. Therefore, this paper analyses behavioral routines and governance structures in the interorganizational maritime transport chain using a case study, dealing with the generation and circulation of transport information at the earliest point available, so called "estimated time of arrival" (ETA.

An overview of the crash dynamics failure behavior of metal and composite aircraft structures

Science.gov (United States)

Carden, Huey D.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.

1991-01-01

An overview of failure behavior results is presented from some of the crash dynamics research conducted with concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. Experimental and analytical data are presented that indicate some general trends in the failure behavior of a class of composite structures that includes fuselage panels, individual fuselage sections, fuselage frames, skeleton subfloors with stringers and floor beams without skin covering, and subfloors with skin added to the frame stringer structure. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models.

Structural transitions and multiferroic properties of high Ni-doped BiFeO3

Science.gov (United States)

Betancourt-Cantera, L. G.; Bolarín-Miró, A. M.; Cortés-Escobedo, C. A.; Hernández-Cruz, L. E.; Sánchez-De Jesús, F.

2018-06-01

Nickel doped bismuth ferrite powders, BiFe1-x NixO3 (0 ≤ x ≤ 0.5), were synthesized by high-energy ball milling followed by an annealing at 700 °C. A detailed study about the substitution of Fe3+ by Ni2+ on the crystal structure and multiferroic properties is presented. The X-ray diffraction patterns reveal the formation of rhombohedral structure with small amounts of Bi2Fe4O9 as a secondary phase for x behavior indicates the frustration of the G-antiferromagnetic order typical of the un-doped BiFeO3, caused by the presence of small amounts of Ni2+ (x Behavior modifications of electrical conductivity, permittivity and dielectric loss versus frequency are related with crystal structure transformations, when nickel concentration is increased.

High-temperature oxidation behavior of dense SiBCN monoliths: Carbon-content dependent oxidation structure, kinetics and mechanisms

International Nuclear Information System (INIS)

Li, Daxin; Yang, Zhihua; Jia, Dechang; Wang, Shengjin; Duan, Xiaoming; Zhu, Qishuai; Miao, Yang; Rao, Jiancun; Zhou, Yu

2017-01-01

Highlights: •The scale growth for all investigated monoliths at 1500 °C cannot be depicted by a linear or parabolic rate law. •The carbon-rich monoliths oxidize at 1500 °C according to a approximately linear weight loss equation. •The excessive carbon in SiBCN monoliths deteriorates the oxidation resistance. •The oxidation resistance stems from the characteristic oxide structures and increased oxidation resistance of BN(C). -- Abstract: The high temperature oxidation behavior of three SiBCN monoliths: carbon-lean SiBCN with substantial Si metal, carbon-moderate SiBCN and carbon-rich SiBCN with excessive carbon, was investigated at 1500 °C for times up to15 h. Scale growth for carbon-lean and −moderate monoliths at 1500 °C cannot be described by a linear or parabolic rate law, while the carbon-rich monoliths oxidize according to a approximately linear weight loss equation. The microstructures of the oxide scale compose of three distinct layers. The passivating layer of carbon and boron containing amorphous SiO 2 and increased oxidation resistance of BN(C) both benefit the oxidation resistance.

High-beta linac structures

International Nuclear Information System (INIS)

Schriber, S.O.

1979-01-01

Accelerating structures for high-beta linacs that have been and are in use are reviewed in terms of their performance. Particular emphasis is given to room-temperature structures and the disk-and-washer structure. The disk-and-washer structure has many attractive features that are discussed for pulsed high-gradient linacs, for 100% duty-cycle medium-gradient linacs and for high-current linacs requiring maximal amounts of stored energy in the electric fields available to the beam

From childhood adversity to problem behaviors: Role of psychological and structural social integration.

Science.gov (United States)

Chao, Lo-Hsin; Tsai, Meng-Che; Liang, Ya-Lun; Strong, Carol; Lin, Chung-Ying

2018-01-01

Childhood adversity (CA) is associated with problem behaviors in adolescence, but the mediators, that is, those factors that help build resilience and prevent some children who experience CA from engaging in problem behaviors, await more exploration, including social integration. The aim of this study was to identify the association between CA and adolescent problem behaviors, and to further examine the mediating role of social integration distinctly as psychological and structural integration. Data used were from the Taiwan Education Panel Survey, a core panel of 4,261 students (age 13) surveyed in 2001 and followed for three more waves until age 18. For psychological integration, an average score was calculated to represent adolescents' feelings about their school. Structural integration was constructed using several items about adolescents' school and extracurricular activities. We used structural equation modeling with the diagonally weighted least squares method to examine the effect of CA on the primary outcome: adolescent problem behaviors via social integration. The hypothesized structural equation model specifying the path from CA to adolescent problem behavior had good fit. Respondents with one CA were indirectly linked to problem behaviors via psychological but not structural integration (e.g. the level of participation in school and non-school activities). On mediation analysis, psychological integration significantly mediated the paths from one CA to all six problem behaviors (all P integration; two or more CA were not associated with significant paths to problem behaviors. The contribution of social integration is crucial to an adolescent's development from CA to problem behaviors. To form supportive social relationships to achieve better health, we suggest that those adolescents who have been exposed to CA should be helped to join more teams and take part in more activities, thereby increasing their opportunities for social interaction, and improving

Optimization of hardening/softening behavior of plane frame structures using nonlinear normal modes

DEFF Research Database (Denmark)

Dou, Suguang; Jensen, Jakob Søndergaard

2016-01-01

Devices that exploit essential nonlinear behavior such as hardening/softening and inter-modal coupling effects are increasingly used in engineering and fundamental studies. Based on nonlinear normal modes, we present a gradient-based structural optimization method for tailoring the hardening...... involving plane frame structures where the hardening/softening behavior is qualitatively and quantitatively tuned by simple changes in the geometry of the structures....

A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

Energy Technology Data Exchange (ETDEWEB)

Yang, Z., E-mail: zhaohui@nwpu.edu.cn; Yu, T. [School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072 (China); Chen, H. [Xi’an Aerospace Propulsion Institute, Xi’an 710100 (China); Li, B. [State Key Laboratory for Manufacturing and Systems Engineering, Xi’an Jiaotong University, Xi’an 710054 (China)

2016-08-15

The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software TEMA Motion is used to track the spot which marked the cage surface. Finally, by developing the MATLAB program, a Lissajous’ figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

International Nuclear Information System (INIS)

Yang, Z.; Yu, T.; Chen, H.; Li, B.

2016-01-01

The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software TEMA Motion is used to track the spot which marked the cage surface. Finally, by developing the MATLAB program, a Lissajous’ figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

High Risk Sexual Behaviors for HIV among the In-School Youth in Swaziland: A Structural Equation Modeling Approach

OpenAIRE

Sacolo, Hlengiwe Nokuthula; Chung, Min-Huey; Chu, Hsin; Liao, Yuan-Mei; Chen, Chiung-Hua; Ou, Keng-Liang; Chang, Lu-I; Chou, Kuei-Ru

2013-01-01

BACKGROUND: Global efforts in response to the increased prevalence of the human immunodeficiency virus (HIV) are mainly aimed at reducing high risk sexual behaviors among young people. However, knowledge regarding intentions of young people to engage in protective sexual behaviors is still lacking in many countries around the world, especially in Sub-Saharan Africa where prevalence of human immunodeficiency virus is the highest. The objective of this study was to test the theory of planned be...

Modeling structural, dyadic, and individual factors: the inclusion and exclusion model of HIV related behavior.

Science.gov (United States)

Albarracin, Dolores; Tannenbaum, Melanie B; Glasman, Laura R; Rothman, Alexander J

2010-12-01

Changing HIV-related behaviors requires addressing the individual, dyadic, and structural influences that shape them. This supplement of AIDS & Behavior presents frameworks that integrate these three influences on behavior. Concepts from these frameworks were selected to model the processes by which structural factors affect individual HIV-related behavior. In the Inclusion/Exclusion Model, material and symbolic inclusions and exclusions (sharing versus denying resources) regulate individuals' ability and motivation to detect, prevent, and treat HIV. Structural interventions create inclusions that increase one's ability or motivation to perform these behaviors or exclusions that hinder one's ability or motivation to execute counterproductive behaviors. The need to expand research regarding multilevel influences on HIV-related behavior is also discussed, particularly concerning further understanding of sustained behavior change and effective dissemination of evidence-based intervention strategies.

High-energy behavior of field-strength interactions

International Nuclear Information System (INIS)

Levin, D.N.

1976-01-01

It is known that spontaneously broken gauge theories are the only renormalizable theories of massive spin-one particles with mass dimension less than or equal to 4. This paper describes a search for renormalizable interactions with higher mass dimension. Specifically, we examine the high-energy behavior of a class of models which involve field-strength interactions. Power counting shows that the high-energy behavior of these models is no worse than the naively estimated high-energy behavior of a gauge theory in the U gauge. Therefore, there may be a ''soft'' symmetry-breaking mechanism (for instance, a soft divergence of an antisymmetric tensor current) which enforces renormalizable high-energy behavior in the same way that spontaneously broken gauge invariance guarantees the renormalizability of gauge theories. This hope is supported by the existence of ''gauge theories'' of strings, which describe analogous interactions of strings and field strengths. Unfortunately, this idea is tarnished by explicit calculations in which renormalizability is imposed in the form of unitarity bounds. These unitarity bounds imply that all possible field-strength couplings must be zero and that the remaining interactions describe a spontaneously broken gauge theory. Thus this result supports an earlier conjecture that gauge theories are the only renormalizable theories of massive vector bosons

A phenotypic structure and neural correlates of compulsive behaviors in adolescents.

Directory of Open Access Journals (Sweden)

Chantale Montigny

Full Text Available A compulsivity spectrum has been hypothesized to exist across Obsessive-Compulsive disorder (OCD, Eating Disorders (ED, substance abuse (SA and binge-drinking (BD. The objective was to examine the validity of this compulsivity spectrum, and differentiate it from an externalizing behaviors dimension, but also to look at hypothesized personality and neural correlates.A community-sample of adolescents (N=1938; mean age 14.5 years, and their parents were recruited via high-schools in 8 European study sites. Data on adolescents' psychiatric symptoms, DSM diagnoses (DAWBA and substance use behaviors (AUDIT and ESPAD were collected through adolescent- and parent-reported questionnaires and interviews. The phenotypic structure of compulsive behaviors was then tested using structural equation modeling. The model was validated using personality variables (NEO-FFI and TCI, and Voxel-Based Morphometry (VBM analysis.Compulsivity symptoms best fit a higher-order two factor model, with ED and OCD loading onto a compulsivity factor, and BD and SA loading onto an externalizing factor, composed also of ADHD and conduct disorder symptoms. The compulsivity construct correlated with neuroticism (r=0.638; p ≤ 0.001, conscientiousness (r=0.171; p ≤ 0.001, and brain gray matter volume in left and right orbitofrontal cortex, right ventral striatum and right dorsolateral prefrontal cortex. The externalizing factor correlated with extraversion (r=0.201; p ≤ 0.001, novelty-seeking (r=0.451; p ≤ 0.001, and negatively with gray matter volume in the left inferior and middle frontal gyri.Results suggest that a compulsivity spectrum exists in an adolescent, preclinical sample and accounts for variance in both OCD and ED, but not substance-related behaviors, and can be differentiated from an externalizing spectrum.

A Phenotypic Structure and Neural Correlates of Compulsive Behaviors in Adolescents

Science.gov (United States)

Montigny, Chantale; Castellanos-Ryan, Natalie; Whelan, Robert; Banaschewski, Tobias; Barker, Gareth J.; Büchel, Christian; Gallinat, Jürgen; Flor, Herta; Mann, Karl; Paillère-Martinot, Marie-Laure; Nees, Frauke; Lathrop, Mark; Loth, Eva; Paus, Tomas; Pausova, Zdenka; Rietschel, Marcella; Schumann, Gunter; Smolka, Michael N.; Struve, Maren; Robbins, Trevor W.; Garavan, Hugh; Conrod, Patricia J.

2013-01-01

Background A compulsivity spectrum has been hypothesized to exist across Obsessive-Compulsive disorder (OCD), Eating Disorders (ED), substance abuse (SA) and binge-drinking (BD). The objective was to examine the validity of this compulsivity spectrum, and differentiate it from an externalizing behaviors dimension, but also to look at hypothesized personality and neural correlates. Method A community-sample of adolescents (N=1938; mean age 14.5 years), and their parents were recruited via high-schools in 8 European study sites. Data on adolescents’ psychiatric symptoms, DSM diagnoses (DAWBA) and substance use behaviors (AUDIT and ESPAD) were collected through adolescent- and parent-reported questionnaires and interviews. The phenotypic structure of compulsive behaviors was then tested using structural equation modeling. The model was validated using personality variables (NEO-FFI and TCI), and Voxel-Based Morphometry (VBM) analysis. Results Compulsivity symptoms best fit a higher-order two factor model, with ED and OCD loading onto a compulsivity factor, and BD and SA loading onto an externalizing factor, composed also of ADHD and conduct disorder symptoms. The compulsivity construct correlated with neuroticism (r=0.638; p≤0.001), conscientiousness (r=0.171; p≤0.001), and brain gray matter volume in left and right orbitofrontal cortex, right ventral striatum and right dorsolateral prefrontal cortex. The externalizing factor correlated with extraversion (r=0.201; p≤0.001), novelty-seeking (r=0.451; p≤0.001), and negatively with gray matter volume in the left inferior and middle frontal gyri. Conclusions Results suggest that a compulsivity spectrum exists in an adolescent, preclinical sample and accounts for variance in both OCD and ED, but not substance-related behaviors, and can be differentiated from an externalizing spectrum. PMID:24244633

INVESTIGATION OF THERMAL BEHAVIOR OF MULTILAYERED FIRE RESISTANT STRUCTURE

Directory of Open Access Journals (Sweden)

R. GUOBYS

2016-09-01

Full Text Available This paper presents experimental and numerical investigations of thermal behavior under real fire conditions of new generation multilayered fire resistant structure (fire door, dimensions H × W × D: 2090 × 980 × 52 mm combining high strength and fire safety. This fire door consists of two steel sheets (thickness 1.5 and 0.7 mm with stone wool ( = 33 kg/m3, k = 0.037 W/mK, E = 5000 N/m2,  = 0.2 insulating layer in between. One surface of the structure was heated in fire furnace for specified period of time of 60 min. Temperature and deformation of opposite surface were measured from outside at selected measuring points during fire resistance test. Results are presented as temperature-time and thermal deformation-time graphs. Experimental results were compared with numerical temperature field simulation results obtained from SolidWorks®Simulation software. Numerical results were found to be in good agreement with experimental data. The percent differences between door temperatures from simulation and fire resistance test don’t exceed 8%. This shows that thermal behaviour of such multilayered structures can be investigated numerically, thus avoiding costly and time-consuming fire resistance tests. It is established that investigated structure should be installed in a way that places thicker steel sheet closer to the potential heat source than thinner one. It is also obtained that stone wool layer of higher density should be used to improve fire resistance of the structure.

Determination of Healthy Lifestyle Behaviors of High School Students

Science.gov (United States)

Çelebi, Evrim; Gündogdu, Cemal; Kizilkaya, Aysel

2017-01-01

Healthy lifestyle behaviors can be defined as all the behaviors believed and applied by individuals to be healthy, maintain health and be protected from diseases. This study aims to determine the healthy lifestyle behaviors of high school students studying at the high schools in the Province of Elazig, Turkey. The study population of this…

High-pressure structural and elastic properties of Tl₂O₃

Energy Technology Data Exchange (ETDEWEB)

Gomis, O., E-mail: osgohi@fis.upv.es; Vilaplana, R. [Centro de Tecnologías Físicas, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Santamaría-Pérez, D. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, 46100 Burjassot (Spain); Earth Sciences Department, University College London, Gower Street, WC1E 6BT London (United Kingdom); Ruiz-Fuertes, J. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, 46100 Burjassot (Spain); Geowissenschaften, Goethe-Universität, Altenhöferallee 1, 60438 Frankfurt am Main (Germany); Sans, J. A.; Manjón, F. J.; Mollar, M. [Instituto de Diseño para la Fabricación y Producción Automatizada, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); and others

2014-10-07

The structural properties of Thallium (III) oxide (Tl₂O₃) have been studied both experimentally and theoretically under compression at room temperature. X-ray powder diffraction measurements up to 37.7 GPa have been complemented with ab initio total-energy calculations. The equation of state of Tl₂O₃ has been determined and compared to related compounds. It has been found experimentally that Tl₂O₃ remains in its initial cubic bixbyite-type structure up to 22.0 GPa. At this pressure, the onset of amorphization is observed, being the sample fully amorphous at 25.2 GPa. The sample retains the amorphous state after pressure release. To understand the pressure-induced amorphization process, we have studied theoretically the possible high-pressure phases of Tl₂O₃. Although a phase transition is theoretically predicted at 5.8 GPa to the orthorhombic Rh₂O₂-II-type structure and at 24.2 GPa to the orthorhombic α-Gd₂S₃-type structure, neither of these phases were observed experimentally, probably due to the hindrance of the pressure-driven phase transitions at room temperature. The theoretical study of the elastic behavior of the cubic bixbyite-type structure at high-pressure shows that amorphization above 22 GPa at room temperature might be caused by the mechanical instability of the cubic bixbyite-type structure which is theoretically predicted above 23.5 GPa.

New insight in magnetic saturation behavior of nickel hierarchical structures

Science.gov (United States)

Ma, Ji; Zhang, Jianxing; Liu, Chunting; Chen, Kezheng

2017-09-01

It is unanimously accepted that non-ferromagnetic inclusions in a ferromagnetic system will lower down total saturation magnetization in unit of emu/g. In this study, ;lattice strain; was found to be another key factor to have critical impact on magnetic saturation behavior of the system. The lattice strain determined assembling patterns of primary nanoparticles in hierarchical structures and was intimately related with the formation process of these architectures. Therefore, flower-necklace-like and cauliflower-like nickel hierarchical structures were used as prototype systems to evidence the relationship between assembling patterns of primary nanoparticles and magnetic saturation behaviors of these architectures. It was found that the influence of lattice strain on saturation magnetization outperformed that of non-ferromagnetic inclusions in these hierarchical structures. This will enable new insights into fundamental understanding of related magnetic effects.

Observing preschoolers' social-emotional behavior: structure, foundations, and prediction of early school success.

Science.gov (United States)

Denham, Susanne A; Bassett, Hideko Hamada; Thayer, Sara K; Mincic, Melissa S; Sirotkin, Yana S; Zinsser, Katherine

2012-01-01

Social-emotional behavior of 352 3- and 4-year-olds attending private child-care and Head Start programs was observed using the Minnesota Preschool Affect Checklist, Revised (MPAC-R). Goals of the investigation included (a) using MPAC-R data to extract a shortened version, MPAC-R/S, comparing structure, internal consistency, test-retest reliability, and stability of both versions; and, using the shortened measure, to examine (b) age, gender, and risk status differences in social-emotional behaviors; (c) contributions of emotion knowledge and executive function to social-emotional behaviors; and (d) contributions of social-emotional behaviors to early school adjustment and kindergarten academic success. Results show that reliability of MPAC-R/S was as good, or better, than the MPAC-R. MPAC-R/S structure, at both times of observation, included emotionally negative/aggressive, emotionally regulated/prosocial, and emotionally positive/productive behaviors; MPAC-R structure was similar but less replicable over time. Age, gender, and risk differences were found. Children's emotion knowledge contributed to later emotionally regulated/prosocial behavior. Finally, preschool emotionally negative/aggressive behaviors were associated with concurrent and kindergarten school success, and there was evidence of social-emotional behavior mediating relations between emotion knowledge or executive function, and school outcomes. The importance of portable, empirically supported observation measures of social-emotional behaviors is discussed along with possible applications, teacher utilization, and implementation barriers.

In-situ investigations of structural changes during cyclic loading by high resolution reciprocal space mapping

DEFF Research Database (Denmark)

Diederichs, Annika M.; Thiel, Felix; Lienert, Ulrich

2017-01-01

dislocation structures can be identified using advanced electron microscopy and synchrotron techniques. A detailed characterization of the microstructure during cyclic loading by in-situ monitoring the internal structure within individual grains with high energy x-rays can help to understand and predict...... the materials behavior during cyclic deformation and to improve the material design. While monitoring macroscopic stress and strain during cyclic loading, reciprocal space maps of diffraction peaks from single grains are obtained with high resolution. High Resolution Reciprocal Space Mapping was applied...

Microstructure and wear behavior of austempered high carbon high silicon steel

Directory of Open Access Journals (Sweden)

Acharya Palaksha

2018-01-01

Full Text Available In the present investigation, the influence of austempering temperature and time on the microstructure and dry sliding wear behavior of high silicon steel was studied. The test specimens were initially austenitised at 900°C for 30 minutes, thereafter austempered at various temperatures 280°C, 360°C and 400°C, for varying duration from 30 to 120 minutes. These samples after austempering heat treatment were subsequently air cooled to room temperature, to generate typical ausferritic microstructures and then correlated with the wear property. The test outcomes demonstrate the slight increase in specific wear rate with increase in both austempering temperature and time. Specific wear rate was found to be minimum at an austempering temperature of 280°C, that exhibits lower bainite microstructure with high hardness, on the other hand specific wear rate was found to be slightly high at increased austempering temperatures at 360°C and 400°C, due to the upper bainite structure that offered lower hardness to the matrix. The sample austempered at 280°C for 30 minutes offered superior wear resistance when compared to other austempering conditions, mainly due to the presence of fine acicular bainitic ferrite along with stabilized retained austenite and also some martensite in the microstructure.

Fracture Toughness and Fatigue Crack Growth Behavior of As-Cast High-Entropy Alloys

Science.gov (United States)

Seifi, Mohsen; Li, Dongyue; Yong, Zhang; Liaw, Peter K.; Lewandowski, John J.

2015-08-01

The fracture toughness and fatigue crack growth behavior of two as-vacuum arc cast high-entropy alloys (HEAs) (Al0.2CrFeNiTi0.2 and AlCrFeNi2Cu) were determined. A microstructure examination of both HEA alloys revealed a two-phase structure consisting of body-centered cubic (bcc) and face-centered cubic (fcc) phases. The notched and fatigue precracked toughness values were in the range of those reported in the literature for two-phase alloys but significantly less than recent reports on a single phase fcc-HEA that was deformation processed. Fatigue crack growth experiments revealed high fatigue thresholds that decreased significantly with an increase in load ratio, while Paris law slopes exhibited metallic-like behavior at low R with significant increases at high R. Fracture surface examinations revealed combinations of brittle and ductile/dimpled regions at overload, with some evidence of fatigue striations in the Paris law regime.

Structural behavior of concrete box bridge using embedded FBG sensors

Science.gov (United States)

Chung, Wonseok; Kang, Donghoon

2012-04-01

For the structural monitoring of railway bridges, electromagnetic interference (EMI) is a significant problem as modern railway lines are powered by high-voltage electric power feeding systems. Fiber optic sensing systems are free from EMI and have been successfully applied in civil engineering fields. This study presents the application of fiber Bragg grating (FBG)-based sensing systems to precast concrete box railway bridges. A 20 m long full-scale precast concrete box railway girder was fabricated and tested in order to identify its static performance. The experimental program involved the measurement of the nonlinear static behavior until failure. Multiplexed FBG strain sensors were embedded along the length of steel rebar and a strain-induced wavelength shift was measured in order to monitor internal strains. The measured values from the FBG-based sensors are compared with the results using electric signal-based sensors. The results show that the FBG sensing system is promising and can improve the efficiency of structural monitoring for modern railway bridges.

Family Structure Changes and Children's Health, Behavior, and Educational Outcomes

DEFF Research Database (Denmark)

Rasmussen, Astrid Würtz

More and more children do not grow up in traditional nuclear families. Instead, they grow up in single-parent households or in families with a step-parent. Hence, it is important to improve our understanding of the impact of "shocks" in family structure due to parental relationship dissolution...... on children. In this study I empirically test whether children are traumatized both in the short and the long run by shocks in the family structure during childhood. I focus on educational, behavioral, and health outcomes. A population sample of Danish children born in January to May 1985 is used...... for the analysis. The empirical cross-sectional analysis indicates a negative relation between the number of family structure changes and children.s health, behavior, and educational outcomes. These results are con.rmed by a differences-in-differences analysis of health outcomes. This suggests...

Simple Syllabic Calls Accompany Discrete Behavior Patterns in Captive Pteronotus parnellii: An Illustration of the Motivation-Structure Hypothesis

Directory of Open Access Journals (Sweden)

Matthew J. Clement

2012-01-01

Full Text Available Mustached bats, Pteronotus parnellii, are highly social and vocal. Individuals of this species roost in tight clusters, and emit an acoustically rich repertoire of calls whose behavioral significance is largely unknown. We recorded their social and vocal behaviors within a colony housed under semi-natural conditions. We also quantified the spatial spread of each bat’s roosting location and discovered that this was relatively fixed and roughly confined to an individual’s body width. The spatial precision in roosting was accompanied by an equally remarkable match between specific vocalizations and well-timed, discrete, identifiable postures/behaviors, as revealed by logistic regression analysis. The bodily behaviors included crouching, marking, yawning, nipping, flicking, fighting, kissing, inspecting, and fly-bys. Two echolocation-like calls were used to maintain spacing in the colony, two noisy broadband calls were emitted during fights, two tonal calls conveyed fear, and another tonal call signaled appeasement. Overall, the results establish that mustached bats exhibit complex social interactions common to other social mammals. The correspondence of relatively low frequency and noisy, broadband calls with aggression, and of tonal, high frequency calls with fear supports Morton’s Motivation-Structure hypothesis, and establishes a link between motivation and the acoustic structure of social calls emitted by mustached bats.

Investigation of structural materials of reactors using high-energy heavy-ion irradiations

International Nuclear Information System (INIS)

Wang Zhiguang

2007-01-01

Radiation damage in structural materials of fission/fusion reactors is mainly attributed to the evolution of intensive atom displacement damage induced by energetic particles (n, α and/or fission fragments) and high-rate helium doping by direct α particle bombardments and/or (n, α) reactions. It can cause severe degradation of reactor structural materials such as surface blistering, bulk void swelling, deformation, fatigue, embrittlement, stress erosion corrosion and so on that will significantly affect the operation safety of reactors. However, up to now, behavior of structural materials at the end of their service can hardly be fully tested in a real reactor. In the present work, damage process in reactor structural materials is briefly introduced, then the advantages of energetic ion implantation/irradiation especially high-energy heavy ion irradiation are discussed, and several typical examples on simulation of radiation effects in reactor candidate structural materials using high-energy heavy ion irradiations are pronounced. Experimental results and theoretical analysis suggested that irradiation with energetic particles especially high-energy heavy ions is very useful technique for simulating the evolution of microstructures and macro-properties of reactor structural materials. Furthermore, an on-going plan of material irradiation experiments using high energy H- and He-ions based on the Heavy Ion Research Facilities in Lanzhou (HIRFL) is also briefly interpreted. (authors)

High aspect ratio titanium nitride trench structures as plasmonic biosensor

DEFF Research Database (Denmark)

Shkondin, Evgeniy; Repän, Taavi; Takayama, Osamu

2017-01-01

High aspect ratio titanium nitride (TiN) grating structures are fabricated by the combination of deep reactive ion etching (DRIE) and atomic layer deposition (ALD) techniques. TiN is deposited at 500 ◦C on a silicon trench template. Silicon between vertical TiN layers is selectively etched...... to fabricate the high aspect ratio TiN trenches with the pitch of 400 nm and height of around 2.7 µm. Dielectric functions of TiN films with different thicknesses of 18 - 105 nm and post-annealing temperatures of 700 - 900 ◦C are characterized by an ellipsometer. We found that the highest annealing temperature...... of 900 ◦C gives the most pronounced plasmonic behavior with the highest plasma frequency, ωp = 2.53 eV (λp = 490 nm). Such high aspect ratio trench structures function as a plasmonic grating sensor that supports the Rayleigh-Woods anomalies (RWAs), enabling the measurement of changes in the refractive...

Modeling Structural, Dyadic, and Individual Factors: The Inclusion and Exclusion Model of HIV Related Behavior

OpenAIRE

Albarracin, Dolores; Tannenbaum, Melanie B.; Glasman, Laura R.; Rothman, Alexander J.

2010-01-01

Changing HIV-related behaviors requires addressing the individual, dyadic, and structural influences that shape them. This supplement of AIDS & Behavior presents frameworks that integrate these three influences on behavior. Concepts from these frameworks were selected to model the processes by which structural factors affect individual HIV-related behavior. In the Inclusion/Exclusion Model, material and symbolic inclusions and exclusions (sharing versus denying resources) regulate individuals...

Nanomechanical Behavior of High Gas Barrier Multilayer Thin Films.

Science.gov (United States)

Humood, Mohammad; Chowdhury, Shahla; Song, Yixuan; Tzeng, Ping; Grunlan, Jaime C; Polycarpou, Andreas A

2016-05-04

Nanoindentation and nanoscratch experiments were performed on thin multilayer films manufactured using the layer-by-layer (LbL) assembly technique. These films are known to exhibit high gas barrier, but little is known about their durability, which is an important feature for various packaging applications (e.g., food and electronics). Films were prepared from bilayer and quadlayer sequences, with varying thickness and composition. In an effort to evaluate multilayer thin film surface and mechanical properties, and their resistance to failure and wear, a comprehensive range of experiments were conducted: low and high load indentation, low and high load scratch. Some of the thin films were found to have exceptional mechanical behavior and exhibit excellent scratch resistance. Specifically, nanobrick wall structures, comprising montmorillonite (MMT) clay and polyethylenimine (PEI) bilayers, are the most durable coatings. PEI/MMT films exhibit high hardness, large elastic modulus, high elastic recovery, low friction, low scratch depth, and a smooth surface. When combined with the low oxygen permeability and high optical transmission of these thin films, these excellent mechanical properties make them good candidates for hard coating surface-sensitive substrates, where polymers are required to sustain long-term surface aesthetics and quality.

Dynamic behavior of tuning fork shear-force structures in a SNOM system

Energy Technology Data Exchange (ETDEWEB)

Gao, Fengli [Department of Engineering Mechanics, AML, CNMM, Tsinghua University, Beijing 100084 (China); Li, Xide, E-mail: lixide@tsinghua.edu.cn [Department of Engineering Mechanics, AML, CNMM, Tsinghua University, Beijing 100084 (China); Wang, Jia [State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Fu, Yu [Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, 637553 (Singapore)

2014-07-01

Piezoelectric tuning fork shear-force structures are widely used as a distance control unit in a scanning near-field optical microscopy. However, the complex dynamic behavior among the micro-tuning forks (TFs), optical fiber probes, and the probe–surface interactions is still a crucial issue to achieve high-resolution imaging or near-field interaction inspections. Based on nonlinear beam tension-bending vibration theory, vibration equations in both longitudinal and lateral directions have been established when the TF structure and the optical fiber are treated as deformable structures. The relationship of the probe–surface interaction induced by Van der Waals force has been analyzed and the corresponding numerical results used to describe the vibrational behavior of the probe approaching the sample surface are obtained. Meanwhile, the viscous resistance of the liquid film on the sample surface has also been investigated using linear beam-bending vibration theory. Experiments testing the interaction between the probe and the water film on a single crystal silicon wafer have been carried out and the viscous resistance of the water film was estimated using the established equations. Finally, to use the TF-probe structure as a force sensor, the relation between the dynamic response of the TF-probe system and an external force on the probe tip was obtained. - Highlights: • Nonlinear vibration equation is established for a deformable tuning fork probe assembly. • Probe–sample interactions induced by Van der Waals force and viscous resistance are investigated. • The viscous resistance between the probe and the water film is estimated using testing results.

A comparison of hardware description languages. [describing digital systems structure and behavior to a computer

Science.gov (United States)

Shiva, S. G.

1978-01-01

Several high level languages which evolved over the past few years for describing and simulating the structure and behavior of digital systems, on digital computers are assessed. The characteristics of the four prominent languages (CDL, DDL, AHPL, ISP) are summarized. A criterion for selecting a suitable hardware description language for use in an automatic integrated circuit design environment is provided.

Early deprivation increases high-leaning behavior, a novel anxiety-like behavior, in the open field test in rats.

Science.gov (United States)

Kuniishi, Hiroshi; Ichisaka, Satoshi; Yamamoto, Miki; Ikubo, Natsuko; Matsuda, Sae; Futora, Eri; Harada, Riho; Ishihara, Kohei; Hata, Yoshio

2017-10-01

The open field test is one of the most popular ethological tests to assess anxiety-like behavior in rodents. In the present study, we examined the effect of early deprivation (ED), a model of early life stress, on anxiety-like behavior in rats. In ED animals, we failed to find significant changes in the time spent in the center or thigmotaxis area of the open field, the common indexes of anxiety-like behavior. However, we found a significant increase in high-leaning behavior in which animals lean against the wall standing on their hindlimbs while touching the wall with their forepaws at a high position. The high-leaning behavior was decreased by treatment with an anxiolytic, diazepam, and it was increased under intense illumination as observed in the center activity. In addition, we compared the high-leaning behavior and center activity under various illumination intensities and found that the high-leaning behavior is more sensitive to illumination intensity than the center activity in the particular illumination range. These results suggest that the high-leaning behavior is a novel anxiety-like behavior in the open field test that can complement the center activity to assess the anxiety state of rats. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Beyond dichotomies-(m)others' structuring and the development of toddlers' prosocial behavior across cultures.

Science.gov (United States)

Kärtner, Joscha

2018-04-01

Basic elements of prosociality-(pro)social cognition, motivation, and prosocial behavior-emerge during the first and second year of life. These elements are rooted in biological predispositions and the developmental system is complemented by caregivers' structuring. By structuring, (m)others integrate toddlers' unrefined (pro)social sentiments and behavioral inclinations into coherent patterns and align toddlers' experience and behavior with the population's cultural model. These cultural models specify target states for appropriate affective, motivational and behavioral responses regarding toddlers' prosociality and these target states, in turn, inform (m)others' appraisal and guide their structuring. The experiences that toddlers make in these social interactions have important implications for how the basic elements of prosociality are refined and further develop. Copyright © 2017 Elsevier Ltd. All rights reserved.

Users structure and behavior on an online social network during a political protest

Science.gov (United States)

Morales, A. J.; Losada, J. C.; Benito, R. M.

2012-11-01

Over the past years, new technologies and specially online social networks have penetrated into the world’s population at an accelerated pace. In this paper we analyze collected data from the web application Twitter, in order to describe the structure and dynamics of the emergent social networks, based on complexity science. We focused on a Venezuelan protest that took place exclusively by Twitter during December, 2010. We found a community structure with highly connected hubs and three different kinds of user behavior that determine the information flow dynamics. We noticed that even though online social networks appear to be a pure social environment, traditional media still holds loads of influence inside the network.

Behavioral response and cell morphology changes of caenorhabditis elegans under high power millimeter wave irradiation

International Nuclear Information System (INIS)

Ren Changhong; Gao Yan; Wu Yonghong; Xu Zhiwei; Zhang Chenggang; Yuan Guangjiang; Xu Shouxi; Su Yinong; Liu Pukun

2010-01-01

C. elegans were exposed to high power millimeter waves (MMWs) with different mean power densities, to investigate their behavioral response and cell morphology changes under MMW irradiation. The time-course photomicrography system was used to record the behavioral changes of C. elegans. The behavioral response and cell morphology changes were further observed by stereoscopic microscopes. The results show that freely moving C. elegans will escape from the MMW irradiation region quickly. After the exposure to MMWs with output mean power of 10 W and 12 W, the bending speed of C. elegans increases significantly at first, while the movement gradually slows down until the bodies get rigid. However, exposed to 5 W MMW, C. elegans show a distinctive tolerant reaction because of the thermal effect. In addition, cell morphological observations show that the nuclear structure of the eggs are abnormal after abnormal after MMW irradiation. High power MMW significantly affects the behaviors and cell morphology of C. elegans, which suggests the C. elegans could be used as a typical model species to study the biological effects of MMW irradiation. (authors)

Examining the Relationship between Holistic/Analytic Style and Classroom Learning Behaviors of High School Students

Science.gov (United States)

Cheng, Hong-Yu; Zhang, Shu-Qiang

2017-01-01

The purpose of this study was to investigate whether and how high school students' cognitive tendencies in holistic/analytic style relate to their active or passive behavioral patterns observed in the classroom. It was speculated that academic intrinsic motivation might play the role as a moderator and learning approach (the structure-oriented…

Low-Cycle Fatigue Behavior of 10CrNi3MoV High Strength Steel and Its Undermatched Welds.

Science.gov (United States)

Song, Wei; Liu, Xuesong; Berto, Filippo; Razavi, S M J

2018-04-24

The use of high strength steel allows the design of lighter, more slender and simpler structures due to high strength and favorable ductility. Nevertheless, the increase of yield strength does not guarantee the corresponding improvement of fatigue resistance, which becomes a major concern for engineering structure design, especially for the welded joints. The paper presents a comparison of the low cycle fatigue behaviors between 10CrNi3MoV high strength steel and its undermatched weldments. Uniaxial tension tests, Push-pull, strain-controlled fatigue tests were conducted on base metal and weldments in the strain range of 0.2⁻1.2%. The monotonic and cyclic stress-strain curves, stress-life, strain-life and energy-life in terms of these materials were analyzed for fatigue assessment of materials discrepancy. The stress-life results of base metal and undermatched weld metal exhibit cyclic softening behaviors. Furthermore, the shapes of 10CrNi3MoV steel hysteresis loops show a satisfactory Masing-type behavior, while the weld metal shows a non-Masing type behavior. Strain, plastic and total strain energy density amplitudes against the number of reversals to failure results demonstrate that the undermatched weld metal presents a higher resistance to fatigue crack initiation than 10CrNi3MoV high strength steel. Finally, fatigue fracture surfaces of specimens were compared by scanning electron microscopy to identify the differences of crack initiation and the propagation between them.

Low-Cycle Fatigue Behavior of 10CrNi3MoV High Strength Steel and Its Undermatched Welds

Directory of Open Access Journals (Sweden)

Wei Song

2018-04-01

Full Text Available The use of high strength steel allows the design of lighter, more slender and simpler structures due to high strength and favorable ductility. Nevertheless, the increase of yield strength does not guarantee the corresponding improvement of fatigue resistance, which becomes a major concern for engineering structure design, especially for the welded joints. The paper presents a comparison of the low cycle fatigue behaviors between 10CrNi3MoV high strength steel and its undermatched weldments. Uniaxial tension tests, Push-pull, strain-controlled fatigue tests were conducted on base metal and weldments in the strain range of 0.2–1.2%. The monotonic and cyclic stress-strain curves, stress-life, strain-life and energy-life in terms of these materials were analyzed for fatigue assessment of materials discrepancy. The stress-life results of base metal and undermatched weld metal exhibit cyclic softening behaviors. Furthermore, the shapes of 10CrNi3MoV steel hysteresis loops show a satisfactory Masing-type behavior, while the weld metal shows a non-Masing type behavior. Strain, plastic and total strain energy density amplitudes against the number of reversals to failure results demonstrate that the undermatched weld metal presents a higher resistance to fatigue crack initiation than 10CrNi3MoV high strength steel. Finally, fatigue fracture surfaces of specimens were compared by scanning electron microscopy to identify the differences of crack initiation and the propagation between them.

High-Risk Driving Behaviors among Adolescent Binge-Drinkers

Science.gov (United States)

Marcotte, Thomas D.; Bekman, Nicole M.; Meyer, Rachel A.; Brown, Sandra A.

2013-01-01

Background Binge drinking is common among adolescents. Alcohol use, and binge-drinking in particular, has been associated with neurocognitive deficits as well as risk-taking behaviors, which may contribute to negative driving outcomes among adolescents even while sober. Objectives To examine differences in self-reported driving behaviors between adolescent binge-drinkers and a matched sample of controls, including (a) compliance with graduated licensing laws, (b) high risk driving behaviors, and (c) driving outcomes (crashes, traffic tickets). Methods The present study examined driving behaviors and outcomes in adolescent recent binge drinkers (n=21) and demographically and driving history matched controls (n=17), ages 16-18. Results Binge drinkers more frequently violated graduated licensing laws (e.g., driving late at night), and engaged in more “high risk” driving behaviors, such as speeding and using a cell-phone while driving. Binge drinkers had more traffic tickets, crashes and “near crashes” than the control group. In a multivariate analysis, binge drinker status and speeding were the most robust predictors of a crash. Conclusion Binge drinking teens consistently engage in more dangerous driving behaviors and experience more frequent crashes and traffic tickets. They are also less compliant with preventative restrictions placed on youth while they are learning critical safe driving skills. Scientific Significance These findings highlight a need to examine the contribution of underlying traits (such as sensation seeking) and binge-related cognitive changes to these high-risk driving behaviors, which may assist researchers in establishing alternative prevention and policy efforts targeting this population. PMID:22324748

High School Sports Involvement Diminishes the Association Between Childhood Conduct Disorder and Adult Antisocial Behavior.

Science.gov (United States)

Samek, Diana R; Elkins, Irene J; Keyes, Margaret A; Iacono, William G; McGue, Matt

2015-07-01

Life course-persistent antisocial behavior manifests as a display of aggressive and antisocial behavior beginning in childhood (conduct disorder [CD]) and lasting through adulthood (adult antisocial personality disorder). This study aimed to build on prior research by evaluating whether involvement in high school sports helped attenuate the association between CD and subsequent adult antisocial behavior (AAB). A prospective sample of 967 male and female adolescents (56% adopted) was used. Structured interviews were used to assess CD (symptoms before the age of 15 years), involvement in sports during high school, and past-year adult antisocial personality disorder symptoms in young adulthood (M age = 22.4 years). As expected, the association between CD and AAB was significantly less for those involved in sports (β = .28; p antisocial behavior in the model (age, gender, adoption status), and results were consistent across males and females. Involvement in other extracurricular activities (e.g., student government, plays, clubs) did not significantly moderate the relationship between CD and AAB. Although selection effects were evident (those with more CD symptoms were less likely to be involved in sports), findings nevertheless suggest high school sports involvement may be a notable factor related to disrupting persistent antisocial behavior beginning in childhood and adolescence and lasting through young adulthood. Implications are discussed. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Centrifuge Testing and Seismic Response Analysis for Uplift Behavior of Spread Foundation Structures on Rock

Directory of Open Access Journals (Sweden)

Takuya Suzuki

2016-09-01

Full Text Available The uplift behavior of structures subjected to severe seismic motion has not been clarified. This paper presents experimental and analytical studies conducted for clarifying this problem of spread foundation structures on rock. First, centrifugal loading tests are conducted to determine the uplift behavior of these structures, and the uplift behavior of these structures is confirmed. Then, simulation analyses are performed using a three-dimensional FE model and the accuracy of these analyses is confirmed. A comparison between test and analyses results clarified the important analytical conditions required for maintaining analysis precision and the limit of analysis precision.

High temperature deformation behavior and microstructural evolutions of a high Zr containing WE magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Asqardoust, Sh.; Zarei-Hanzaki, A. [School of Metallurgical & Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Fatemi, S.M., E-mail: mfatemi@ut.ac.ir [Shahid Rajaee Teacher Training University, Tehran (Iran, Islamic Republic of); Moradjoy-Hamedani, M. [School of Metallurgical & Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

2016-06-05

Magnesium alloys containing RE elements (WE grade) are considered as potential materials for high temperature structural applications. To this end, it is crucial to study the flow behavior and the microstructural evolution of these alloys at high temperatures. In present work, the hot compression testing was employed to investigate the deformation behavior of a rolled WE54 magnesium alloy at elevated temperatures. The experimental material failed to deform to target strain of 0.6 at 250 and 300 °C, while the straining was successfully performed at 350 °C. A flow softening was observed at 350 °C, which was related to the depletion of RE strengthener elements, particularly Y atoms, from the solid solution and dynamic precipitation of β phases. It was suggested that the Zener pinning effect of the latter precipitates might retard the occurrence of dynamic recrystallization. As the temperature increased to 450 and 500 °C, the RE elements dissolved in the matrix and thus dynamic recrystallization could considerably progress in the microstructure. The comparative study of specimens cut along transverse ad normal direction (TD and ND specimens) implied that the presence of RE elements might effectively reduce the yield anisotropy in WE54 rolled alloy. Microstructural observations indicated a higher fraction of dynamically-recrystallized grains for the ND specimens. This was discussed relying on the different shares of deformation mechanism during compressing the TD and ND specimens. - Highlights: • Deformation behavior of a high Zr WE alloy was addressed at low strain rate. • Dynamic precipitation was realized at 350 °C. • The occurrence of DRX was retarded due to Zener pinning effect. • A higher DRX fraction was obtained in ND specimens comparing with TD ones.

Behavior and strength of beams cast with ultra high strength concrete containing different types of fibers

Directory of Open Access Journals (Sweden)

M.M. Kamal

2014-04-01

Full Text Available Ultra-high performance concrete (UHPC is a special type of concrete with extraordinary potentials in terms of strength and durability performance. Its production and application implement the most up-to-date knowledge and technology of concrete manufacturing. Sophisticated structural designs in bridges and high-rise buildings, repair works and special structures like nuclear facilities are currently the main fields of applications of UHPC. This paper aimed to evaluate the behavior of ultra-high strength concrete beams. This paper also aimed to determine the effect of adding fibers and explore their effect upon the behavior and strength of the reinforced concrete beams. A total of twelve simple concrete beams with and without shear reinforcements were tested in flexure. The main variables taken into consideration in this research were the type of fibers and the percentage of longitudinal reinforcement as well as the existence or absence of the web reinforcement. Two types of fibers were used including steel and polypropylene fibers. The behavior of the tested beams was investigated with special attention to the deflection under different stages of loading, initial cracking, cracking pattern, and ultimate load. Increased number of cracks was observed at the end of loading due to the use of fibers, which led to the reduced width of cracks. This led to increased stiffness and higher values of maximum loads.

Comparative study on two different seal surface structure for reactor pressure vessel sealing behavior

International Nuclear Information System (INIS)

Chen Jun; Xiong Guangming; Deng Xiaoyun

2014-01-01

The seal surface structure is very important to reactor pressure vessel (RPV) sealing behavior. In this paper, two 3-D RPV sealing analysis finite models have been established with different seal surface structures, in order to study the influence of two structures. The separation of RPV upper and lower flanges, bolt loads and etc. are obtained, which are used to evaluate the sealing behavior of the RPV. Meanwhile, the comparative analysis of safety margin of two seal surface structural had been done, which provides the theoretical basis for RPV seal structure design optimization. (authors)

Impulsivity, aggression and brain structure in high and low lethality suicide attempters with borderline personality disorder.

Science.gov (United States)

Soloff, Paul; White, Richard; Diwadkar, Vaibhav A

2014-06-30

Impulsivity and aggressiveness are trait dispositions associated with the vulnerability to suicidal behavior across diagnoses. They are associated with structural and functional abnormalities in brain networks involved in regulation of mood, impulse and behavior. They are also core characteristics of borderline personality disorder (BPD), a disorder defined, in part, by recurrent suicidal behavior. We assessed the relationships between personality traits, brain structure and lethality of suicide attempts in 51 BPD attempters using multiple regression analyses on structural MRI data. BPD was diagnosed by the Diagnostic Interview for Borderline Patients-revised, impulsivity by the Barratt Impulsiveness Scale (BIS), aggression by the Brown-Goodwin Lifetime History of Aggression (LHA), and high lethality by a score of 4 or more on the Lethality Rating Scale (LRS). Sixteen High Lethality attempters were compared to 35 Low Lethality attempters, with no significant differences noted in gender, co-morbidity, childhood abuse, BIS or LHA scores. Degree of medical lethality (LRS) was negatively related to gray matter volumes across multiple fronto-temporal-limbic regions. Effects of impulsivity and aggression on gray matter volumes discriminated High from Low Lethality attempters and differed markedly within lethality groups. Lethality of suicide attempts in BPD may be related to the mediation of these personality traits by specific neural networks. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Electronic structure of the copper oxides: Band picture versus correlated behavior

Energy Technology Data Exchange (ETDEWEB)

Pickett, W E; Cohen, R E; Singh, D [Naval Research Lab., Washington, DC (USA); Krakauer, H [Coll. of William and Mary, Williamsburg, VA (USA)

1989-12-01

In the 2 1/2 years since the discovery of the high temperature superconducting copper oxides, a great deal has been learned from experiment about their behavior. From the theoretical side, there continues to be developments both within the band picture and from the model Hamiltonian viewpoint emphasizing correlations. In this paper we discuss briefly these complementary viewpoints in relation to certain of the experimental data. Due to our background in the band structure area, we approach the discussion by evaluating which phenomena can be (or has been) accounted for by the standard band approach, and point out which properties appear to require more intricate treatments of correlation. (orig.).

Work hardening behavior study of structural alloys for cryogenic applications

International Nuclear Information System (INIS)

Chu, D.; Morris, J.W. Jr.

1992-01-01

Previous investigation on aluminum-lithium alloys have indicated different dependencies of the work hardening behavior on temperature. This variation in temperature dependence is attributed to differences in microstructure rather than composition. An understanding of the microstructural effect on the observed thermal dependency is important as it may allow the tailoring of deformation properties through mechanical processing. Work hardening analyses on other aluminum alloys and a number of structural steels have been performed to better elucidate the role played by microstructure in determining the work hardening behavior. In the paper correlations between the differences in mechanical behavior and the various microstructures observed are presented

Association of maltreatment with high-risk internet behaviors and offline encounters.

Science.gov (United States)

Noll, Jennie G; Shenk, Chad E; Barnes, Jaclyn E; Haralson, Katherine J

2013-02-01

High-risk Internet behaviors, including viewing sexually explicit content, provocative social networking profiles, and entertaining online sexual solicitations, were examined in a sample of maltreated and nonmaltreated adolescent girls aged 14 to 17 years. The impact of Internet behaviors on subsequent offline meetings was observed over 12 to 16 months. This study tested 2 main hypotheses: (1) maltreatment would be a unique contributor to high-risk Internet behaviors and (2) high-quality parenting would dampen adolescents' propensity to engage in high-risk Internet behaviors and to participate in offline meetings. Online and offline behaviors and parenting quality were gleaned from 251 adolescent girls, 130 of whom experienced substantiated maltreatment and 121 of whom were demographically matched comparison girls. Parents reported on adolescent behaviors and on the level of Internet monitoring in the home. Social networking profiles were objectively coded for provocative self-presentations. Offline meetings with persons first met online were assessed 12 to 16 months later. Thirty percent of adolescents reported having offline meetings. Maltreatment, adolescent behavioral problems, and low cognitive ability were uniquely associated with high-risk Internet behaviors. Exposure to sexual content, creating high-risk social networking profiles, and receiving online sexual solicitations were independent predictors of subsequent offline meetings. High-quality parenting and parental monitoring moderated the associations between adolescent risk factors and Internet behaviors, whereas use of parental control software did not. Treatment modalities for maltreated adolescents should be enhanced to include Internet safety literacy. Adolescents and parents should be aware of how online self-presentations and other Internet behaviors can increase vulnerability for Internet-initiated victimization.

The Examination of the Effectiveness of an Educational Intervention based on the Planned Behavior Theory on Improving Pubertal Health Behavior in Female High School Students

Directory of Open Access Journals (Sweden)

Farnaz Eslamimehr

2017-09-01

Full Text Available Background: Puberty is a period of psychological, physical, mental, emotional and social growth that stability and development of personality occurs in this period. This study aimed to determine the effect of planned behavior theory on improving pubertal health behavior in female first grade high school students. Materials and Methods:  A quasi-experimental intervention was conducted in female high school in Khamir city, Iran in 2015. One of the schools were randomly assigned to the control group and other to the experimental group. Using the formula sample, 60 students were selected from each school. Samples were evaluated in two stages through pre-test and two months later via post-test by administered questionnaire including questions about demographic characteristics and structures of planned behavior theory. The content of training was presented through lecture group discussion with teaching aids such as booklet and pamphlet. The collected data were analyzed using SPSS version 22. Results: The intervention group mean age at first menstrual period was 12.30 ± 0.84 years old and for control group was 12.25 ± 0.79 years old. The results showed that two months after the intervention, health behaviors, subjective norms, behavioral intention, perceived behavioral control, and attitude, were significantly higher than pre- intervention (P

Pricing Decision under Dual-Channel Structure considering Fairness and Free-Riding Behavior

Directory of Open Access Journals (Sweden)

Yongmei Liu

2014-01-01

Full Text Available Under dual-channel structure, the free-riding behavior based on different service levels between online channel and offline channel cannot be avoided, which would lead to channel unfairness. This study implies that the dual-channel supply chain is built up by online channel controlled by manufacturer and traditional channel controlled by retailer, respectively. Under this channel structure, we rebuild the linear demand function considering free-riding behavior and modify the pricing model based on channel fairness. Then the influences of fair factor and free-riding behavior on manufacturer and retailer pricing and performance are discussed. Finally, we propose some numerical analysis to provide some valuable recommendations for manufacturer and retailer improving channel management performance.

Thermo-Mechanical Behavior and Shakedown of Shape Memory Alloy Cable Structures

Science.gov (United States)

Biggs, Daniel B.

Shape memory alloys (SMAs) are a versatile class of smart materials that exhibit adaptive properties which have been applied to solve engineering problems in wide-ranging fields from aerospace to biomedical engineering. Yet there is a lack of understanding of the fundamental nature of SMAs in order to effectively apply them to challenging problems within these engineering fields. Stranding fine NiTi wires into a cable form satisfies the demands of many aerospace and civil engineering applications which require actuators to withstand large tensile loads. The impact of increased bending and twisting in stranded NiTi wire structures, as well as introducing contact mechanics to the unstable phase transformation is not well understood, and this work aims to fill that void. To study the scalability of NiTi cables, thermo-mechanical characterization tests are conducted on cables much larger than those previously tested. These cables are found to have good superelastic properties and repeatable cyclic behavior with minimal induced plasticity. The behavior of additional cables, which have higher transition temperatures that can be used in a shape memory mode as thermo-responsive, high force actuator elements, are explored. These cables are found to scale up the performance of straight wire by maintaining an equivalent work output. Moreover, this work investigates the degradation of the thermal actuation of SMA wires through novel stress-temperature paths, discovering several path dependent behaviors of transformation-induced plasticity. The local mechanics of NiTi cable structures are explored through experiments utilizing digital image correlation, revealing new periodic transformation instabilities. Finite element simulations are presented, which indicate that the instabilities are caused by friction and relative sliding between wires in a cable. Finally, a study of the convective heat transfer of helical wire involving a suite of wind tunnel experiments, numerical

Peel testing behavior of mushroom-top terminated structured adhesives

Science.gov (United States)

Hossfeld, Craig Kenneth

Synthetic structured surfaces have been created based on the extraordinary adhesive ability exhibited by insects, spiders, and geckos. The adhesion of synthetic and natural structured adhesives is attributed to the cumulative addition of van der Waals forces acting on the structures of the surface. It has been shown that for synthetic surfaces a "mushroom top" or "flanged" terminating structure exhibits the highest adhesion. Unfortunately, due to the variety of testing and fabrication techniques and the small scale of previous studies, the detachment behavior of these structures is not well understood. This research systematically investigated the effect of peel angle, pillar diameter, flange diameter, and pillar aspect ratio on the force required for peeling. Explicit emphasis was placed on relatively large pillar structures to allow for in situ optical visualization in order to gain insights into fundamental mechanisms which dictate peeling. Traditional molding techniques were used to fabricate optical-scale mushroom terminated structures with pillar diameters of 1mm and 400microm and aspect ratios of 1, 3, and 5. Results were quantitatively compared to peel testing theory for conventional adhesives. It was convincingly demonstrated that the adhesive energy of a patterned surface changes as function of angle, and cannot be treated as a constant. The variability in the energy was linked to mechanistic differences in detachment through in situ observations and finite element analysis. Experimental results show that smaller pillars do not necessarily lead to higher adhesion during peeling, aspect ratio plays little role in peeling adhesive behavior, and pillar flange size is critical to adhesion. The conclusions from this study outline design parameters for mushroom topped dry adhesives in peeling applications.

Predicting High-School Students' Bystander Behavior in Simulated Dating Violence Situations.

Science.gov (United States)

Jouriles, Ernest N; Rosenfield, David; Yule, Kristen; Sargent, Kelli S; McDonald, Renee

2016-03-01

Dating violence among adolescents is associated with a variety of negative health consequences for victims. Bystander programs are being developed and implemented with the intention of preventing such violence, but determinants of high-school students' responsive bystander behavior remain unclear. The present study examines hypothesized determinants of high-school students' bystander behavior in simulated situations of dating violence. Participants were 80 high-school students who completed self-reports of hypothesized determinants of bystander behavior (responsibility, efficacy, and perceived benefits for intervening) at a baseline assessment. A virtual-reality paradigm was used to observationally assess bystander behavior at 1-week and 6-month assessments after baseline. Efficacy for intervening was positively associated with observed bystander behavior at the 1-week and 6-month assessments. Moreover, efficacy predicted bystander behavior over and above feelings of responsibility and perceived benefits for intervening. Contrary to our predictions, neither responsibility nor perceived benefits for intervening were associated with observed bystander behavior. This research advances our understanding of determinants of bystander behavior for high-school students and can inform prevention programming for adolescents. The study also introduces an innovative way to assess high-school students' bystander behavior. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Experimental Study of Structure/Behavior Relationship for a Metallized Explosive

Science.gov (United States)

Bukovsky, Eric; Reeves, Robert; Gash, Alexander; Glumac, Nick

2017-06-01

Metal powders are commonly added to explosive formulations to modify the blast behavior. Although detonation velocity is typically reduced compared to the neat explosive, the metal provides other benefits. Aluminum is a common additive to increase the overall energy output and high-density metals can be useful for enhancing momentum transfer to a target. Typically, metal powder is homogeneously distributed throughout the material; in this study, controlled distributions of metal powder in explosive formulations were investigated. The powder structures were printed using powder bed printing and the porous structures were filled with explosives to create bulk explosive composites. In all cases, the overall ratio between metal and explosive was maintained, but the powder distribution was varied. Samples utilizing uniform distributions to represent typical materials, discrete pockets of metal powder, and controlled, graded powder distributions were created. Detonation experiments were performed to evaluate the influence of metal powder design on the output pressure/time and the overall impulse. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Behavioral correlates of changes in hippocampal gray matter structure during acquisition of foreign vocabulary.

Science.gov (United States)

Bellander, Martin; Berggren, Rasmus; Mårtensson, Johan; Brehmer, Yvonne; Wenger, Elisabeth; Li, Tie-Qiang; Bodammer, Nils C; Shing, Yee-Lee; Werkle-Bergner, Markus; Lövdén, Martin

2016-05-01

Experience can affect human gray matter volume. The behavioral correlates of individual differences in such brain changes are not well understood. In a group of Swedish individuals studying Italian as a foreign language, we investigated associations among time spent studying, acquired vocabulary, baseline performance on memory tasks, and gray matter changes. As a way of studying episodic memory training, the language learning focused on acquiring foreign vocabulary and lasted for 10weeks. T1-weighted structural magnetic resonance imaging and cognitive testing were performed before and after the studies. Learning behavior was monitored via participants' use of a smartphone application dedicated to the study of vocabulary. A whole-brain analysis showed larger changes in gray matter structure of the right hippocampus in the experimental group (N=33) compared to an active control group (N=23). A first path analyses revealed that time spent studying rather than acquired knowledge significantly predicted change in gray matter structure. However, this association was not significant when adding performance on baseline memory measures into the model, instead only the participants' performance on a short-term memory task with highly similar distractors predicted the change. This measure may tap similar individual difference factors as those involved in gray matter plasticity of the hippocampus. Copyright © 2015 Elsevier Inc. All rights reserved.

Wake structure and similar behavior of wake profiles downstream of a plunging airfoil

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Ali R. DAVARI

2017-08-01

Full Text Available Very limited attention has already been paid to the velocity behavior in the wake region in unsteady aerodynamic problems. A series of tests has been performed on a flapping airfoil in a subsonic wind tunnel to study the wake structure for different sets of mean angle of attack, plunging amplitude and reduced frequency. In this study, the velocity profiles in the wake for various oscillation parameters have been measured using a wide shoulder rake, especially designed for the present experiments. The airfoil under consideration was a critical section of a 660 kW wind turbine. The results show that for a flapping airfoil the wake structure can be of drag producing type, thrust producing or neutral, depending on the mean angle of attack, oscillation amplitude and reduced frequency. In a thrust producing wake, a high-momentum high-velocity jet flow is formed in the core region of the wake instead of the conventional low-momentum flow. As a result, the drag force normally experienced by the body due to the momentum deficit would be replaced by a thrust force. According to the results, the momentum loss in the wake decreases as the reduced frequency increases. The thrust producing wake pattern for the flapping airfoil has been observed for sufficiently low angles of attack in the absence of the viscous effects. This phenomenon has also been observed for either high oscillation amplitudes or high reduced frequencies. According to the results, for different reduced frequencies and plunging amplitudes, such that the product of them be a constant, the velocity profiles exhibit similar behavior and coalesce on each other. This similarity parameter works excellently at small angles of attack. However, at near stall boundaries, the similarity is not as evident as before.

Simulation and modeling of the crushing behavior of structural members

International Nuclear Information System (INIS)

Toi, Yutaka

1986-01-01

The analysis of the crushing behavior (the behavior of compressive breakdown accompanied by super large deformation) of structural members is an important subject which becomes the base of the ultimate strength design of the structures which may cause collision accident such as automobiles, ships and aircrafts, and of those which are feared to be collided such as offshore structures, bridge piers and nuclear power plants. However, since it is a phenomenon of very strong nonlinearity, its analysis is accompanied by large difficulty. In this report, three kinds of the approach for this problem, that is, rigid-plastic theoretical analysis, the simulation using a rigid body and spring model and nonlinear finite element analysis, are explained, referring to the example of calculation by the authors on the non-axisymmetric crushing problem of cylindrical shells. In crushing problem, the matters of concern are the amount of collision energy which can be absorbed by the plastic deformation of structures and the amount of deformation. It can be said that the increase of calculation cost brings about the heightening of calculation accuracy. The nonlinear finite element analysis is promising because its calculation cost is expected to lower in future. (Kako, I.)

Ceramic matrix composites -- Advanced high-temperature structural materials

International Nuclear Information System (INIS)

Lowden, R.A.; Ferber, M.K.; DiPietro, S.G.

1995-01-01

This symposium on Ceramic Matrix Composites: Advanced High-Temperature Structural Materials was held at the 1994 MRS Fall Meeting in Boston, Massachusetts on November 28--December 2. The symposium was sponsored by the Department of Energy's Office of Industrial Technology's Continuous Fiber Ceramic Composites Program, the Air Force Office of Scientific Research, and NASA Lewis Research Center. Among the competing materials for advanced, high-temperature applications, ceramic matrix composites are leading candidates. The symposium was organized such that papers concerning constituents--fibers and matrices--were presented first, followed by composite processing, modeling of mechanical behavior, and thermomechanical testing. More stable reinforcements are necessary to enhance the performance and life of fiber-reinforced ceramic composites, and to ensure final acceptance of these materials for high-temperature applications. Encouraging results in the areas of polymer-derived SiC fibers and single crystal oxide filaments were given, suggesting composites with improved thermomechanical properties and stability will be realized in the near future. The significance of the fiber-matrix interface in the design and performance of these materials is evident. Numerous mechanical models to relate interface properties to composite behavior, and interpret test methods and data, were enthusiastically discussed. One issue of great concern for any advanced material for use in extreme environments is stability. This theme arose frequently throughout the symposium and was the topic of focus on the final day. Fifty nine papers have been processed separately for inclusion on the data base

Health behaviors of Bydgoszcz high school graduates

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Alicja Kostencka

2016-10-01

Full Text Available Lifestyle affects the physical, mental, social development, health and learning ability. It seems that there are differences in the health behaviors  of young females and males, however these differences are not well described. The aim of the current study was to assess the lifestyle of eighteen-years old and to compare their health behaviors of young persons according to their gender. The study was conducted among 98 students of high schools in Bydgoszcz (35 females and 68 males. All participants were 18 years old. The questionnaire was prepared especially for the purposes of the study, a part of the questions of this questionnaire was taken from the Canada Fitness Survey. The physical activity, mode of nutrition, use of stimulants, hours of sleep, time spent in front of screens and the level of stress were taken into consideration while assessing the teenagers’ lifestyle. The lifestyle of high school graduates is worrisome. It is characterized by low level of physical activity, irregular nutrition, not enough fruits, vegetables and water consumed. A large group of young people drink alcohol, smoke tobacco and marijuana, sleep too short. Males also spend too many hours in front of a television, computer or other similar device. Differences in the health behaviors of  women and men appear to be significant. The prevalence of alcohol abuse in this group is very high and affects both sexes. The sex differences in the health-promoting behaviors among men and women in this group of adolescents seems to diminish. Observed unhealthy behaviors indicates the urgent need for health education, especially those that educate the student about the value of the person, the value of health, and the development of social skills that underlie personal development. The foremost priority is  risk prevention implementation in primary schools. Further research and continuous monitoring of health behaviors in different age groups  is needed as well as  to

Evolution of structural, magnetic and transport behavior by Pr doping in SrRuO3

Science.gov (United States)

Gupta, Renu; Pramanik, A. K.

2018-05-01

Here we report the evolution of structural, magnetic and transport behavior in perovskite based ruthenates Sr1-xPrxRuO3 (x=0.0 and 0.1). The substitution of Pr on Sr site retains orthorhombic structure while we find the slight change in structural parameters. The SrRuO3 has itinerant ferromagnet (FM) type nature of ordering temperature ˜160 K and below the transition temperature showing large bifurcation between ZFC and FC magnetization. By Pr doping, the magnetic moment decreases with decreasing bifurcation of ZFC and FC. The ZFC data show three distinct peaks (three transition temperature; TM1,TM2 and TM3). The magnetization study of both the samples, at high temperature fitted with modified CWL showing the decreasing value of ordering temperature by Pr doping matches close to TM2. The low-temperature isothermal magnetization M (H) data show that the high field saturation moment has decreased by Pr doping. The Arrott plot gives spontaneous magnetization (Ms) which is also decreased by Pr substitution. Evolution of Rhodes-Wohlfarth ratio value increases, which suggests that FM in this system evolves toward the more itinerant type by Pr doping. The electrical resistivity ρ(T) of both the samples show metallic behavior, in the all temperature range and ρ(T) increases by Pr doping while around below 45 K, the resistivity decreases by Pr doping and this crossing temperature also matches with ZFC data.

Non Linear Analyses for the Evaluation of Seismic Behavior of Mixed R.C.-Masonry Structures

International Nuclear Information System (INIS)

Liberatore, Laura; Tocci, Cesare; Masiani, Renato

2008-01-01

In this work the seismic behavior of masonry buildings with mixed structural system, consisting of perimeter masonry walls and internal r.c. frames, is studied by means of non linear static (pushover) analyses. Several aspects, like the distribution of seismic action between masonry and r.c. elements, the local and global behavior of the structure, the crisis of the connections and the attainment of the ultimate strength of the whole structure are examined. The influence of some parameters, such as the masonry compressive and tensile strength, on the structural behavior is investigated. The numerical analyses are also repeated on a building in which the r.c. internal frames are replaced with masonry walls

Structure and mechanical behavior of bird beaks

Science.gov (United States)

Seki, Yasuaki

The structure and mechanical behavior of Toco toucan (Ramphastos toco) and Wreathed hornbill (Rhyticeros undulatus) beaks were examined. The structure of Toco toucan and Wreathed hornbill beak was found to be a sandwich composite with an exterior of keratin and a fibrous bony network of closed cells made of trabeculae. A distinctive feature of the hornbill beak is its casque formed from cornified keratin layers. The casque is believed to have an acoustic function due to the complex internal structure. The toucan and hornbill beaks have a hollow region that extends from proximal to mid-section. The rhamphotheca is comprised of super-posed polygonal scales (45 mum diameter and 1 mum thickness) fixed by some organic adhesive. The branched intermediate filaments embedded in keratin matrix were discovered by transmission electron microscopy (TEM). The diameter of intermediate laments was ~10 nm. The orientation of intermediate filaments was examined with TEM tomography and the branched filaments were homogeneously distributed. The closed-cell foam is comprised of the fibrous structure of bony struts with an edge connectivity of three or four and the cells are sealed off by the thin membranes. The volumetric structure of bird beak foam was reproduced by computed tomography for finite element modeling.

Structural Dynamic Behavior of Wind Turbines

Science.gov (United States)

Thresher, Robert W.; Mirandy, Louis P.; Carne, Thomas G.; Lobitz, Donald W.; James, George H. III

2009-01-01

The structural dynamicist s areas of responsibility require interaction with most other members of the wind turbine project team. These responsibilities are to predict structural loads and deflections that will occur over the lifetime of the machine, ensure favorable dynamic responses through appropriate design and operational procedures, evaluate potential design improvements for their impact on dynamic loads and stability, and correlate load and control test data with design predictions. Load prediction has been a major concern in wind turbine designs to date, and it is perhaps the single most important task faced by the structural dynamics engineer. However, even if we were able to predict all loads perfectly, this in itself would not lead to an economic system. Reduction of dynamic loads, not merely a "design to loads" policy, is required to achieve a cost-effective design. The two processes of load prediction and structural design are highly interactive: loads and deflections must be known before designers and stress analysts can perform structural sizing, which in turn influences the loads through changes in stiffness and mass. Structural design identifies "hot spots" (local areas of high stress) that would benefit most from dynamic load alleviation. Convergence of this cycle leads to a turbine structure that is neither under-designed (which may result in structural failure), nor over-designed (which will lead to excessive weight and cost).

Assessing Actual Visit Behavior through Antecedents of Tourists Satisfaction among International Tourists in Jordan: A Structural Equation Modeling (SEM Approach

Directory of Open Access Journals (Sweden)

Ayed Moh’d Al Muala

2011-06-01

Full Text Available Jordan tourism industry is facing fluctuating tourist visit provoked by dissatisfaction, high visit risk, low hotel service, or negative Jordan image. This study aims to examine the relationships between the antecedents of tourist satisfaction and actual visit behavior in tourism of Jordan, and the mediating effect of tourist satisfaction (SAT in the relationship between Jordan image (JOM, service climate (SER and actual visit behavior (ACT. A total of 850 international tourists completed a survey that were conducted at southern sites in Jordan. Using structural equation modeling (SEM technique, confirmatory Factor Analysis (CFA was performed to examine the reliability and validity of the measurement, and the structural equation modeling techniques (Amos 6.0 were used to evaluate the casual model. Results of the study demonstrate the strong predictive power and explain of international tourists’ behavior in Jordan. The findings highlighted that the relationship between Jordan image and service climate are significant and positive on actual visit behavior.

An explanation of the irreversibility behavior in the highly- anisotropic high-temperature superconductors

International Nuclear Information System (INIS)

Gray, K.E.; Kim, D.H.

1991-01-01

The wide temperature range of the reversible, lossy state of the new high-temperature superconductors in a magnetic field was recognized soon after their discovery. This behavior, which had gone virtually undetected in conventional superconductors, has generated considerable interest, both for a fundamental understanding of the HTS and because it degrades the performance of HTS for finite-field applications. We show that recently proposed explanation of this behavior for the highly-anisotropic high-temperature superconductors, as a dimensional crossover of the magnetic vortices, is strongly supported by recent experiments on a Bi 2 Sr 2 CaCu 2 O x single crystal using the high-Q mechanical oscillator techniques

Hypersexuality and high sexual desire: exploring the structure of problematic sexuality.

Science.gov (United States)

Carvalho, Joana; Štulhofer, Aleksandar; Vieira, Armando L; Jurin, Tanja

2015-06-01

The concept of hypersexuality has been accompanied by fierce debates and conflicting conclusions about its nature. One of the central questions under the discussion is a potential overlap between hypersexuality and high sexual desire. With the relevant research in its early phase, the structure of hypersexuality remains largely unknown. The aim of the present study was to systematically explore the overlap between problematic sexuality and high sexual desire. A community online survey was carried out in Croatia in 2014. The data were first cluster analyzed (by gender) based on sexual desire, sexual activity, perceived lack of control over one's sexuality, and negative behavioral consequences. Participants in the meaningful clusters were then compared for psychosocial characteristics. To complement cluster analysis (CA), multigroup confirmatory factor analysis (CFA) of the same four constructs was carried out. Indicators representing the proposed structure of hypersexuality were included: sexual desire, frequency of sexual activity, lack of control over one's sexuality, and negative behavioral outcomes. Psychosocial characteristics such as religiosity, attitudes toward pornography, and general psychopathology were also evaluated. CA pointed to the existence of two meaningful clusters, one representing problematic sexuality, that is, lack of control over one's sexuality and negative outcomes (control/consequences cluster), and the other reflecting high sexual desire and frequent sexual activity (desire/activity cluster). Compared with the desire/activity cluster, individuals from the control/consequences cluster reported more psychopathology and were characterized by more traditional attitudes. Complementing the CA findings, CFA pointed to two distinct latent dimensions-problematic sexuality and high sexual desire/activity. Our study supports the distinctiveness of hypersexuality and high sexual desire/activity, suggesting that problematic sexuality might be more

A numerical study on the structural behavior of underground rock caverns for radioactive waste disposal

International Nuclear Information System (INIS)

Kim, Sun Hoon; Choi, Kyu Sup; Lee, Kyung Jin; Kim, Dae Hong

1991-01-01

In order to design safe and economical underground disposal structures for radioactive wastes, understanding the behavior of discontinuous rock masses is essential. This study includes discussions about the computational model for discontinuous rock masses and the structural analysis method for underground storage structures. Then, based on an engineering judgement a suitable selection and slight modifications on computational models and analysis methods have been made in order to analyze and understand the structural behavior of the rock cavern with discontinuities

DASH - Youth Risk Behavior Surveillance System (YRBSS): High School

Data.gov (United States)

U.S. Department of Health & Human Services — 1991-2015. High School Dataset. The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health behaviors among youth and young...

Technology Enabled Work: The Role of Self-Efficacy in Determining Telecommuter Adjustment and Structuring Behavior.

Science.gov (United States)

Raghuram, Sumita; Wiesenfeld, Batia; Garud, Raghu

2003-01-01

Responses from 31.5% of 723 telecommuters revealed a positive association between self-efficacy and both adjustment to teleworking and behaviors for structuring work. The more extensive the telecommuting, the stronger these positive relationships. Women were more proactive in structuring work behavior. (Contains 43 references.) (SK)

Mechanical properties of LMR structural materials at high temperature

International Nuclear Information System (INIS)

Kim, D. W.; Kuk, I. H.; Ryu, W. S. and others

1999-03-01

Austenitic stainless is used for the structural material of liquid metal reactor (LMR) because of good mechanical properties at high temperature. Stainless steel having more resistant to temperature by adding minor element has been developing for operating the LMR at higher temperature. Of many elements, nitrogen is a prospective element to modify type 316L(N) stainless steel because nitrogen is the most effective element for solid solution and because nitrogen retards the precipitation of carbide at grain boundary. Ti, Nb, and V are added to improve creep properties by stabilizing the carbides through forming MC carbide. Testing techniques of tensile, fatigue, creep, and creep-fatigue at high temperature are difficult. Moreover, testing times for creep and creep-fatigue tests are very long up to several tens of thousands hours because creep and creep-fatigue phenomena are time-dependent damage mechanism. So, it is hard to acquire the material data for designing LMR systems during a limited time. In addition, the integrity of LMR structural materials at the end of LMR life has to be predicted from the laboratory data tested during the short term because there is no data tested during 40 years. Therefore, the effect of elements on mechanical properties at high temperature was reviewed in this study and many methods to predict the long-term behaviors of structural materials by simulated modelling equation is shown in this report. (author). 32 refs., 9 tabs., 38 figs

A quaternary lead based perovskite structured materials with diffuse phase transition behavior

International Nuclear Information System (INIS)

Puli, Venkata Sreenivas; Martínez, R.; Kumar, Ashok; Scott, J.F.; Katiyar, Ram S.

2011-01-01

Graphical abstract: (a) Curie–Weiss plot for the inverse of the relative dielectric permittivity and (b) log (1/ε − 1/ε m ) as function of log (T − T m ) for ceramics at 1 kHz. Highlights: ► Retaining phase pure structure with quaternary complex stoichiometric compositions. ► P–E loops with good saturation polarization (P s ∼ 30.7 μC/cm 2 ). ► Diffused relaxor phase transition behavior with γ estimated is ∼1.65. -- Abstract: A lead based quaternary compound composed of 0.25(PbZr 0.52 Ti 0.48 O 3 ) + 0.25(PbFe 0.5 Ta 0.5 O 3 ) + 0.25 (PbF 0.67 W 0.33 O 3 ) + 0.25(PbFe 0.5 Nb 0.5 O 3 ) – (PZT–PFT–PFW–PFN) was synthesized by conventional solid-state reaction techniques. It showed moderate high dielectric constant, low dielectric loss, and two diffuse phase transitions, one below the room temperature ∼261 K and other above ∼410 K. X-ray diffraction (XRD) patterns revealed a tetragonal crystal structure at room temperature where as scanning electron micrograph (SEM) indicates inhomogeneous surface with an average grain size of 500 nm–3 μm. Well saturated ferroelectric hysteresis loops with good saturation polarization (spontaneous polarization, P s ∼ 30.68 μC/cm 2 ) were observed. Temperature-dependent ac conductivity displayed low conductivity with kink in spectra near the phase transition. In continuing search for developing new ferroelectric materials, in the present study we report stoichiometric compositions of complex perovskite ceramic materials: (PZT–PFT–PFW–PFN) with diffuse phase transition behavior. The crystal structure, dielectric properties, and ferroelectric properties were characterized by XRD, SEM, dielectric spectroscopy, and polarization. 1/ε versus (T) plots revealed diffuse relaxor phase transition (DPT) behavior. The compositional variation on the phase transition temperature, dielectric constant, and ferroelectric to paraelectric phase transitions are discussed.

A quaternary lead based perovskite structured materials with diffuse phase transition behavior

Energy Technology Data Exchange (ETDEWEB)

Puli, Venkata Sreenivas, E-mail: pvsri123@gmail.com [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States); Martinez, R.; Kumar, Ashok [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States); Scott, J.F. [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States); Cavendish Laboratory, Dept. Physics, University of Cambridge, Cambridge CB0 3HE (United Kingdom); Katiyar, Ram S., E-mail: rkatiyar@uprrp.edu [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States)

2011-12-15

Graphical abstract: (a) Curie-Weiss plot for the inverse of the relative dielectric permittivity and (b) log (1/{epsilon} - 1/{epsilon}{sub m}) as function of log (T - T{sub m}) for ceramics at 1 kHz. Highlights: Black-Right-Pointing-Pointer Retaining phase pure structure with quaternary complex stoichiometric compositions. Black-Right-Pointing-Pointer P-E loops with good saturation polarization (P{sub s} {approx} 30.7 {mu}C/cm{sup 2}). Black-Right-Pointing-Pointer Diffused relaxor phase transition behavior with {gamma} estimated is {approx}1.65. -- Abstract: A lead based quaternary compound composed of 0.25(PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}) + 0.25(PbFe{sub 0.5}Ta{sub 0.5}O{sub 3}) + 0.25 (PbF{sub 0.67}W{sub 0.33}O{sub 3}) + 0.25(PbFe{sub 0.5}Nb{sub 0.5}O{sub 3}) - (PZT-PFT-PFW-PFN) was synthesized by conventional solid-state reaction techniques. It showed moderate high dielectric constant, low dielectric loss, and two diffuse phase transitions, one below the room temperature {approx}261 K and other above {approx}410 K. X-ray diffraction (XRD) patterns revealed a tetragonal crystal structure at room temperature where as scanning electron micrograph (SEM) indicates inhomogeneous surface with an average grain size of 500 nm-3 {mu}m. Well saturated ferroelectric hysteresis loops with good saturation polarization (spontaneous polarization, P{sub s} {approx} 30.68 {mu}C/cm{sup 2}) were observed. Temperature-dependent ac conductivity displayed low conductivity with kink in spectra near the phase transition. In continuing search for developing new ferroelectric materials, in the present study we report stoichiometric compositions of complex perovskite ceramic materials: (PZT-PFT-PFW-PFN) with diffuse phase transition behavior. The crystal structure, dielectric properties, and ferroelectric properties were characterized by XRD, SEM, dielectric spectroscopy, and polarization. 1/{epsilon} versus (T) plots revealed diffuse relaxor phase transition (DPT) behavior. The

Classroom Activity Structures and the Generalizability of Teacher Behavior.

Science.gov (United States)

Anderson, Lorin W.; Mandeville, Garrett K.

The purpose of this study was to examine the influence of several instructional formats (e.g., lecture, discourse, seatwork) on the generalizability of teacher behaviors. Two structured observation instruments were used to observe two samples of teachers: 42 fifth grade science teachers on eight occasions, and 87 fifth grade mathematics teachers…

Evaluation of thermal displacement behavior of high temperature piping system in power-up test of HTTR. No. 1 results up to 20 MW operation

International Nuclear Information System (INIS)

Hanawa, Satoshi; Kojima, Takao; Sumita, Junya; Tachibana, Yukio

2002-03-01

Temperature of the primary cooling system of the High Temperature Engineering Test Reactor, HTTR, becomes very high because the coolant temperature at the reactor outlet reaches 950degC, and 400degC at inlet of the reactor. Therefore, it is important to confirm the thermal displacement behavior of the high temperature piping system in the primary cooling system from the viewpoint of the structural integrity. Moreover, newly designed 3-dimensional floating support system is adopted to the cooling system, it is meaningful to verify the thermal displacement behavior of the piping system applied the 3-dimensional floating support system. In the power-up test (up to 20 MW operation), thermal displacement behavior of the high temperature piping system was measured. This paper describes the experimental and analytical results of thermal displacement characteristics of the high temperature piping system. The results showed that the resistance force induced from the supporting system effects to the thermal displacement behavior of cooling system, and the analytical results have a good agreement with the experimental results by optimizing the resistant force of the floating support system. Additionally, structural integrity at the 30 MW operation was confirmed by the analysis. (author)

Femtosecond laser fabricated spike structures for selective control of cellular behavior.

Science.gov (United States)

Schlie, Sabrina; Fadeeva, Elena; Koch, Jürgen; Ngezahayo, Anaclet; Chichkov, Boris N

2010-09-01

In this study we investigate the potential of femtosecond laser generated micrometer sized spike structures as functional surfaces for selective cell controlling. The spike dimensions as well as the average spike to spike distance can be easily tuned by varying the process parameters. Moreover, negative replications in soft materials such as silicone elastomer can be produced. This allows tailoring of wetting properties of the spike structures and their negative replicas representing a reduced surface contact area. Furthermore, we investigated material effects on cellular behavior. By comparing human fibroblasts and SH-SY5Y neuroblastoma cells we found that the influence of the material was cell specific. The cells not only changed their morphology, but also the cell growth was affected. Whereas, neuroblastoma cells proliferated at the same rate on the spike structures as on the control surfaces, the proliferation of fibroblasts was reduced by the spike structures. These effects can result from the cell specific adhesion patterns as shown in this work. These findings show a possibility to design defined surface microstructures, which could control cellular behavior in a cell specific manner.

Molybdenum peroxo complex. Structure and thermal behavior

Energy Technology Data Exchange (ETDEWEB)

Segawa, Koichi; Ooga, Katsumi; Kurusu, Yasuhiko

1984-10-01

The molybdenum peroxide (Mo-y) prepared by oxidation of molybdenum metal with hydrogen peroxide has been studied to determine its structure and thermal behavior. Temperature programmed decomposition has been used to study the thermal stability of Mo-y. Two distinct peaks, I and II, of decomposition processes are discernible in Mo-y. Peak I corresponds to the elimination of water of crystallization and peak II to the decomposition of a peroxide ion of Mo-y. IR and UV examinations support the results of the thermal analysis. The IR band at 931 cm/sup -1/ and the UV band at 381 nm show the same thermal behavior. Both bands are attributable to the peroxide ion of Mo-y. Spectroscopic studies show that Mo-y has the tetrahedral coordination derived from the single molybdenum complex, which has double bond oxygens attached to Mo atom and has a symmetric type of peroxide ion with one water of crystallization.

Behavioral responses in structured populations pave the way to group optimality.

Science.gov (United States)

Akçay, Erol; Van Cleve, Jeremy

2012-02-01

An unresolved controversy regarding social behaviors is exemplified when natural selection might lead to behaviors that maximize fitness at the social-group level but are costly at the individual level. Except for the special case of groups of clones, we do not have a general understanding of how and when group-optimal behaviors evolve, especially when the behaviors in question are flexible. To address this question, we develop a general model that integrates behavioral plasticity in social interactions with the action of natural selection in structured populations. We find that group-optimal behaviors can evolve, even without clonal groups, if individuals exhibit appropriate behavioral responses to each other's actions. The evolution of such behavioral responses, in turn, is predicated on the nature of the proximate behavioral mechanisms. We model a particular class of proximate mechanisms, prosocial preferences, and find that such preferences evolve to sustain maximum group benefit under certain levels of relatedness and certain ecological conditions. Thus, our model demonstrates the fundamental interplay between behavioral responses and relatedness in determining the course of social evolution. We also highlight the crucial role of proximate mechanisms such as prosocial preferences in the evolution of behavioral responses and in facilitating evolutionary transitions in individuality.

Creep behavior of materials for high-temperature reactor application

International Nuclear Information System (INIS)

Schneider, K.; Hartnagel, W.; Iischner, B.; Schepp, P.

1984-01-01

Materials for high-temperature gas-cooled reactor (HTGR) application are selected according to their creep behavior. For two alloys--Incoloy-800 used for the live steam tubing of the thorium high-temperature reactor and Inconel-617 evaluated for tubings in advanced HTGRs--creep curves are measured and described by equations. A microstructural interpretation is given. An essential result is that nonstable microstructures determine the creep behavior

Probabilistic analysis of structures involving random stress-strain behavior

Science.gov (United States)

Millwater, H. R.; Thacker, B. H.; Harren, S. V.

1991-01-01

The present methodology for analysis of structures with random stress strain behavior characterizes the uniaxial stress-strain curve in terms of (1) elastic modulus, (2) engineering stress at initial yield, (3) initial plastic-hardening slope, (4) engineering stress at point of ultimate load, and (5) engineering strain at point of ultimate load. The methodology is incorporated into the Numerical Evaluation of Stochastic Structures Under Stress code for probabilistic structural analysis. The illustrative problem of a thick cylinder under internal pressure, where both the internal pressure and the stress-strain curve are random, is addressed by means of the code. The response value is the cumulative distribution function of the equivalent plastic strain at the inner radius.

Evaluation of aseismic integrity in the HTTR core-bottom structure. V. On the static and dynamic behavior of graphite HTTR key-keyway structures

International Nuclear Information System (INIS)

Futakawa, M.; Iyoku, T.

1996-01-01

For pt.IV see ibid., vol.154, p.83-95, 1995. The graphite components in high temperature gas-cooled reactors are connected to each other through a key-keyway structure that has gaps between the key and the keyway to accommodate thermal expansion. Because a dynamic load concentrates on the key-keyway structure during earthquakes, it is considered to be a crucial element for assessing the integrity of the graphite components. A combination of experiments and analyses was employed to investigate the dynamic behavior of the key-keyway structure, i.e. the equivalent stiffness associated with vibrational characteristics of the graphite components and the stress distribution under dynamic loading. The experiments were performed using a graphite scale model and a dynamic photo-elastic method. The analysis was carried out using the finite element method (FEM) code ABAQUS, taking account of the contact behavior between the key and the keyway. The following conclusions were derived. (1) The equivalent stiffness of the key-keyway structure shows nonlinearity, owing to the contact deformation. (2) The equivalent stiffness evaluated by the FEM analysis, taking account of the non-linear contact deformation, is applicable for predicting the vibrational characteristics of the key-keyway structure. (3) The stress concentration under dynamic loading is lower than or nearly equal to that under static loading. The maximum stress concentration of the seismic load can be sufficiently evaluated under static loading conditions. (orig.)

Contrastive Numerical Investigations on Thermo-Structural Behaviors in Mass Concrete with Various Cements

Science.gov (United States)

Zhou, Wei; Feng, Chuqiao; Liu, Xinghong; Liu, Shuhua; Zhang, Chao; Yuan, Wei

2016-01-01

This work is a contrastive investigation of numerical simulations to improve the comprehension of thermo-structural coupled phenomena of mass concrete structures during construction. The finite element (FE) analysis of thermo-structural behaviors is used to investigate the applicability of supersulfated cement (SSC) in mass concrete structures. A multi-scale framework based on a homogenization scheme is adopted in the parameter studies to describe the nonlinear concrete behaviors. Based on the experimental data of hydration heat evolution rate and quantity of SSC and fly ash Portland cement, the hydration properties of various cements are studied. Simulations are run on a concrete dam section with a conventional method and a chemo-thermo-mechanical coupled method. The results show that SSC is more suitable for mass concrete structures from the standpoint of temperature control and crack prevention. PMID:28773517

Nonlinear behaviors of FRP-wrapped tall trees subjected to high wind loads

Science.gov (United States)

Kang, J.; Yi, Z. Z.; Choi, S. G.

2017-12-01

This study investigated the mechanical stability of historical tall trees wrapped with fiber-reinforced polymer (FRP) laminates using finite element (FE) analysis. High wind loads are considered as external loading conditions as they are one of the major threats on the structural stability of tall old trees. There have been several traditional practices to enhance the stability of tall trees exposed to high windstorms such as tree supporters and anchorages. They, however, have been sometimes causing negative effects with their misuses as the application guidelines for those methods were not adequately studied or documented. Furthermore, the oldest known trees in the country should be protected from the damage of external surface as well as ruin of the landscape. The objective of this study was to evaluate the structural effects of FRP wraps applied to tall trees subjected to high wind loads. The anisotropic material properties of wood and FRP laminates were considered in the analysis in addition to geometrically nonlinear behaviors. This study revealed that FRP wrapping for tall trees could effectively reduce the deflections and maximum stresses of trees, which results in the enhanced stability of tall trees. The optimum geometry and thicknesses of FRP wraps proposed in this study would provide fundemental guidelines for designing and constructing the application of innovative FRP wraps on tall trees, which are structurally unstable or should be preserved nationally and historically.

Effects of high magnetic field on martensitic transformation behavior and structure in Fe-based alloys

International Nuclear Information System (INIS)

Ohtsuka, H.; Wada, H.; Ghosh, G.

2000-01-01

Effects of magnetic field on lath-type martensitic transformation behavior and the reverse transformation behavior from lath math martensite to austenite have been investigated in 18Ni maraging steel. It was found that the reverse transformation temperature during heating is increased by magnetic field. Reverse transformation behavior during isothermal holding was also found to be retarded by magnetic field. (orig.)

On static triplet structures in fluids with quantum behavior

Science.gov (United States)

Sesé, Luis M.

2018-03-01

The problem of the equilibrium triplet structures in fluids with quantum behavior is discussed. Theoretical questions of interest to the real space structures are addressed by studying the three types of structures that can be determined via path integrals (instantaneous, centroid, and total thermalized-continuous linear response). The cases of liquid para-H2 and liquid neon on their crystallization lines are examined with path-integral Monte Carlo simulations, the focus being on the instantaneous and the centroid triplet functions (equilateral and isosceles configurations). To analyze the results further, two standard closures, Kirkwood superposition and Jackson-Feenberg convolution, are utilized. In addition, some pilot calculations with path integrals and closures of the instantaneous triplet structure factor of liquid para-H2 are also carried out for the equilateral components. Triplet structural regularities connected to the pair radial structures are identified, a remarkable usefulness of the closures employed is observed (e.g., triplet spatial functions for medium-long distances, triplet structure factors for medium k wave numbers), and physical insight into the role of pair correlations near quantum crystallization is gained.

Thermodynamic behavior of glassy state of structurally related compounds.

Science.gov (United States)

Kaushal, Aditya Mohan; Bansal, Arvind Kumar

2008-08-01

Thermodynamic properties of amorphous pharmaceutical forms are responsible for enhanced solubility as well as poor physical stability. The present study was designed to investigate the differences in thermodynamic parameters arising out of disparate molecular structures and associations for four structurally related pharmaceutical compounds--celecoxib, valdecoxib, rofecoxib, and etoricoxib. Conventional and modulated temperature differential scanning calorimetry were employed to study glass forming ability and thermodynamic behavior of the glassy state of model compounds. Glass transition temperature of four glassy compounds was in a close range of 327.6-331.8 K, however, other thermodynamic parameters varied considerably. Kauzmann temperature, strength parameter and fragility parameter showed rofecoxib glass to be most fragile of the four compounds. Glass forming ability of the compounds fared similar in the critical cooling rate experiments, suggesting that different factors were determining the glass forming ability and subsequent behavior of the compounds in glassy state. A comprehensive understanding of such thermodynamic facets of amorphous form would help in rationalizing the approaches towards development of stable glassy pharmaceuticals.

Fast Food Consumption Behaviors in High-School Students based on the Theory of Planned Behavior (TPB

Directory of Open Access Journals (Sweden)

Kamal Mirkarimi

2016-07-01

Full Text Available Background: Studies report inappropriate snack and junk food consumption patterns in children and young adults in Iran. The current survey was aimed to explore fast food consumption behaviors in high-school students based on the Theory of Planned Behavior. Materials and Methods: A cross-sectional study was done among 500 high-school students. Samples were selected based on cluster sampling method at first and simple random at second. Data were collected using a researcher-made questionnaire. To analyze, SPSS-16 and tests, including t-test, Chi-square, correlation coefficient and multiple regressions were used. Results: The monthly frequency of fast food consumption was 4.01. The TPB explained fast food use behaviors with R2 of 0.6, effectively. Results also represented that frequency of fast food consumption was meaningfully in line with behavioral intention (β = 0.60, P < 0.05 and subjective norms (β = 0.17, P < 0.05. Conclusion: It seems likely beneficial to consider important subjective norms (especially friends that may strongly effect on high-school student intention to use fast food. Also students perceived behavioral control must be increased.

Nonvolatile conductive filaments resistive switching behaviors in Ag/GaO{sub x} /Nb:SrTiO{sub 3}/Ag structure

Energy Technology Data Exchange (ETDEWEB)

Li, P.G. [Beijing University of Posts and Telecommunications, State Key Laboratory of Information Photonics and Optical Communication, Beijing (China); Zhejiang Sci-Tech University, Center for Optoelectronics Materials and Devices, Hangzhou (China); Zhi, Y.S.; An, Y.H.; Guo, D.Y.; Tang, W.H.; Xiao, J.H. [Beijing University of Posts and Telecommunications, State Key Laboratory of Information Photonics and Optical Communication, Beijing (China); Wang, P.C. [Zhejiang Sci-Tech University, Center for Optoelectronics Materials and Devices, Hangzhou (China); Sun, Z.B. [Chinese Academy of Sciences, Key Laboratory of Electronics and Information Technology for Space Systems, National Space Science Center, Beijing (China); Li, L.H. [State University of New York at Potsdam, Department of Physics, Potsdam, NY (United States)

2016-07-15

Ag/GaO{sub x} /NSTO/Ag structures were fabricated, and the electrical properties measurement results show that the device behaviors a unipolar resistance switching characteristic with bi-stable resistance ratio of three orders. In the positive voltage region, the dominant conducting mechanism of high resistance state obeys Poole-Frenkel emission rules, while in the negative region, that obeys space-charge-limited current mechanism. Both the I-V curves of ON and OFF states and temperature-dependent variation resistances indicate that the unipolar resistance switching behavior can be explained by the formation/rupture of conductive filaments, which composed of oxygen vacancies. The stable switching results demonstrated that the structure can be applied in resistance random access memory devices. (orig.)

Stock portfolio structure of individual investors infers future trading behavior.

Science.gov (United States)

Bohlin, Ludvig; Rosvall, Martin

2014-01-01

Although the understanding of and motivation behind individual trading behavior is an important puzzle in finance, little is known about the connection between an investor's portfolio structure and her trading behavior in practice. In this paper, we investigate the relation between what stocks investors hold, and what stocks they buy, and show that investors with similar portfolio structures to a great extent trade in a similar way. With data from the central register of shareholdings in Sweden, we model the market in a similarity network, by considering investors as nodes, connected with links representing portfolio similarity. From the network, we find investor groups that not only identify different investment strategies, but also represent individual investors trading in a similar way. These findings suggest that the stock portfolios of investors hold meaningful information, which could be used to earn a better understanding of stock market dynamics.

Stock portfolio structure of individual investors infers future trading behavior.

Directory of Open Access Journals (Sweden)

Ludvig Bohlin

Full Text Available Although the understanding of and motivation behind individual trading behavior is an important puzzle in finance, little is known about the connection between an investor's portfolio structure and her trading behavior in practice. In this paper, we investigate the relation between what stocks investors hold, and what stocks they buy, and show that investors with similar portfolio structures to a great extent trade in a similar way. With data from the central register of shareholdings in Sweden, we model the market in a similarity network, by considering investors as nodes, connected with links representing portfolio similarity. From the network, we find investor groups that not only identify different investment strategies, but also represent individual investors trading in a similar way. These findings suggest that the stock portfolios of investors hold meaningful information, which could be used to earn a better understanding of stock market dynamics.

Stock Portfolio Structure of Individual Investors Infers Future Trading Behavior

Science.gov (United States)

Bohlin, Ludvig; Rosvall, Martin

2014-01-01

Although the understanding of and motivation behind individual trading behavior is an important puzzle in finance, little is known about the connection between an investor's portfolio structure and her trading behavior in practice. In this paper, we investigate the relation between what stocks investors hold, and what stocks they buy, and show that investors with similar portfolio structures to a great extent trade in a similar way. With data from the central register of shareholdings in Sweden, we model the market in a similarity network, by considering investors as nodes, connected with links representing portfolio similarity. From the network, we find investor groups that not only identify different investment strategies, but also represent individual investors trading in a similar way. These findings suggest that the stock portfolios of investors hold meaningful information, which could be used to earn a better understanding of stock market dynamics. PMID:25068302

A structural model of health behavior modification among patients with cardiovascular disease.

Science.gov (United States)

Goong, Hwasoo; Ryu, Seungmi; Xu, Lijuan

2016-02-01

The purpose of the study was to test a structural equation model in which social support, health beliefs, and stage of change predict the health behaviors of patients with cardiovascular disease. A cross-sectional correlational design was used. Using convenience sampling, a survey about social support, health belief, stage of change, and health behavior was completed by 314 adults with cardiovascular disease from outpatient clinics in 2 university hospitals in Korea. Data were analyzed using a structural equation model with the Analysis of Moment program. The participants were aged 53.44±13.19 years (mean±SD), and about 64% of them were male. The proposed model fit the data from the study well, explaining 19% and 60% of the variances in the stage of change and health behavior, respectively. The findings indicate that the performance of health behavior modification among the patients with cardiovascular disease can be explained by social support, health belief, and stage of change based on a health-belief and stage-of-change model. Further studies are warranted to confirm the efficacy of health-promoting strategies in initiating and maintaining the performance of health behaviors by providing social support from family and medical staff and enhancing health belief. Copyright © 2015 Elsevier Inc. All rights reserved.

Appeals to consumer responsibility and improving structural conditions as means to promote sustainable consumer behavior

DEFF Research Database (Denmark)

Thøgersen, John

for their acts or (b) structural conditions determined by governments? In field experiments with large samples of ordinary consumers, the behavioral effects of perceptions of responsibility/personal moral norms and of altering an important structural condition are quantified by measuring a relevant behavior......-developed public transit service. The results suggest that there is often more to gain from changing structural conditions to be more facilitating for the desired behavior than from a campaign targeting consumer feelings of responsibility.......Environmental policy-makers increasingly emphasize consumers' responsibility for environmental side effects of their acts, but is this justified? This paper investigates which is the most important limiting factor for sustainable consumption: (a) the extent to which consumers assume responsibility...

Conference Analysis Report of Assessments on Defect and Damage for a High Temperature Structure

International Nuclear Information System (INIS)

Lee, Hyeong Yeon

2008-11-01

This report presents the analysis on the state-of-the-art research trends on creep-fatigue damage, defect assessment of high temperature structure, development of heat resistant materials and their behavior at high temperature based on the papers presented in the two international conferences of ASME PVP 2008 which was held in Chicago in July 2008 and CF-5(5th International Conference on Creep, Fatigue and Creep-Fatigue) which was held in Kalpakkam, India in September 2008

Conference Analysis Report of Assessments on Defect and Damage for a High Temperature Structure

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyeong Yeon

2008-11-15

This report presents the analysis on the state-of-the-art research trends on creep-fatigue damage, defect assessment of high temperature structure, development of heat resistant materials and their behavior at high temperature based on the papers presented in the two international conferences of ASME PVP 2008 which was held in Chicago in July 2008 and CF-5(5th International Conference on Creep, Fatigue and Creep-Fatigue) which was held in Kalpakkam, India in September 2008.

Structural behavior of Pd40Cu30Ni10P20 bulk metallic glass below and above the glass transition

DEFF Research Database (Denmark)

Mattern, N.; Hermann, H.; Roth, S.

2003-01-01

The thermal behavior of the structure of Pd40Cu30Ni10P20 bulk metallic glass has been investigated in situ through the glass transition by means of high-temperature x-ray synchrotron diffraction. The dependence of the x-ray structure factor S(q) of the Pd40Cu30Ni10P20 glass on temperature follows...... the Debye theory up to the glass transition with a Debye temperature theta=296 K. Above the glass transition temperature T-g, the temperature dependence of S(q) is altered, pointing to a continuous development of structural changes in the liquid with temperature. The atomic pair correlation functions g......(r) indicate changes in short-range-order parameters of the first and the second neighborhood with temperature. The temperature dependence of structural parameters is different in glass and in supercooled liquid, with a continuous behavior through the glass transition. The nearest-neighbor distance decreases...

Unraveling Crystalline Structure of High-Pressure Phase of Silicon Carbonate

Directory of Open Access Journals (Sweden)

Rulong Zhou

2014-03-01

Full Text Available Although CO_{2} and SiO_{2} both belong to group-IV oxides, they exhibit remarkably different bonding characteristics and phase behavior at ambient conditions. At room temperature, CO_{2} is a gas, whereas SiO_{2} is a covalent solid with rich polymorphs. A recent successful synthesis of the silicon-carbonate solid from the reaction between CO_{2} and SiO_{2} under high pressure [M. Santoro et al., Proc. Natl. Acad. Sci. U.S.A. 108, 7689 (2011] has resolved a long-standing puzzle regarding whether a Si_{x}C_{1−x}O_{2} compound between CO_{2} and SiO_{2} exists in nature. Nevertheless, the detailed atomic structure of the Si_{x}C_{1−x}O_{2} crystal is still unknown. Here, we report an extensive search for the high-pressure crystalline structures of the Si_{x}C_{1−x}O_{2} compound with various stoichiometric ratios (SiO_{2}:CO_{2} using an evolutionary algorithm. Based on the low-enthalpy structures obtained for each given stoichiometric ratio, several generic structural features and bonding characteristics of Si and C in the high-pressure phases are identified. The computed formation enthalpies show that the SiC_{2}O_{6} compound with a multislab three-dimensional (3D structure is energetically the most favorable at 20 GPa. Hence, a stable crystalline structure of the elusive Si_{x}C_{1−x}O_{2} compound under high pressure is predicted and awaiting future experimental confirmation. The SiC_{2}O_{6} crystal is an insulator with elastic constants comparable to typical hard solids, and it possesses nearly isotropic tensile strength as well as extremely low shear strength in the 2D plane, suggesting that the multislab 3D crystal is a promising solid lubricant. These valuable mechanical and electronic properties endow the SiC_{2}O_{6} crystal for potential applications in tribology and nanoelectronic devices, or as a stable solid-state form for CO_{2} sequestration.

Preliminary Guideline for the High Temperature Structure Integrity Assessment Procedure Part II. High Temperature Structural Integrity Assessment

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Han; Kim, J. B.; Lee, H. Y.; Park, C. G.; Joo, Y. S.; Koo, G. H.; Kim, S. H

2007-02-15

A high temperature structural integrity assessment belongs to the Part II of a whole preliminary guideline for the high temperature structure. The main contents of this guideline are the evaluation procedures of the creep-fatigue crack initiation and growth in high temperature condition, the high temperature LBB evaluation procedure, and the inelastic evaluations of the welded joints in SFR structures. The methodologies for the proper inelastic analysis of an SFR structures in high temperatures are explained and the guidelines of inelastic analysis options using ANSYS and ABAQUS are suggested. In addition, user guidelines for the developed NONSTA code are included. This guidelines need to be continuously revised to improve the applicability to the design and analysis of the SFR structures.

Development of low emittance high brightness electron beams and rf accelerating structures

International Nuclear Information System (INIS)

Pellegrini, C.

1991-01-01

The main goals of this project were the construction of an S-band RF photoinjector for the production of a high brightness electron beam, and the development of a new type of RF accelerator structure; the Plane wave transformer. By the end of October 1991 the photoinjector had been built, its RF characteristics had been measured at low power, and an initial test of the gun at high RF power had been done. The Plane Wave Transformer had also been built and tested at lower power. In both cases the results obtained are mostly in agreement with the expected and calculated behavior

The structural integrity of high level waste containers for deep disposal

International Nuclear Information System (INIS)

Keer, T.J.; Martindale, N.J.; Haijtink, B.

1990-01-01

Most countries with a nuclear power program are developing plans to dispose of high level waste in deep geological repositories. These facilities are typically in the range 500-1000m below ground. Although long term safety analyses mainly rely on the isolation function of the geological barrier, for the medium term (between 500 and 1000 years) a barrier such as a container (overpack) may play an important role. This paper addresses the mechanical/structural behavior of these structures under extreme geological pressures. The work described in the paper was conducted within the COMPAS project (Container Mechanical Performance Assessment) funded by the Commission of the European Communities and the United Kingdom Department of the Environment. The work was aimed at predicting the modes of failure and failure pressures which characterize the heavy, thick walled mild steel containers which might be considered for the disposal of vitrified waste. The work involved a considerable amount of analytical work, using 3-D non-linear finite element techniques, coupled with a large parallel program of experimental work. The experimental work consisted of a number of scale model tests in which the response of the containers was examined under external pressures as high as 120MPa. Extensive strain-gauge instrumentation was used to record the behavior of the models as they were driven to collapse. A number of comparative computer calculations were carried out by organizations from various European countries. Correlations were established between experimental and analytical data and guidelines regarding the choice of suitable software were established. The work concluded with a full 3-D simulation of the behavior of a container under long-term disposal conditions. In this analysis, non-linearities due to geological effects and material/geometry effects in the container were properly accounted for. 6 refs., 9 figs., 4 tabs

Dynamic behavior of cellular materials and cellular structures: Experiments and modeling

Science.gov (United States)

Gao, Ziyang

Cellular solids, including cellular materials and cellular structures (CMS), have attracted people's great interests because of their low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They offer potential for lightweight structures, energy absorption, thermal management, etc. Therefore, the studies of cellular solids have become one of the hottest research fields nowadays. From energy absorption point of view, any plastically deformed structures can be divided into two types (called type I and type II), and the basic cells of the CMS may take the configurations of these two types of structures. Accordingly, separated discussions are presented in this thesis. First, a modified 1-D model is proposed and numerically solved for a typical type II structure. Good agreement is achieved with the previous experimental data, hence is used to simulate the dynamic behavior of a type II chain. Resulted from different load speeds, interesting collapse modes are observed, and the parameters which govern the cell's post-collapse behavior are identified through a comprehensive non-dimensional analysis on general cellular chains. Secondly, the MHS specimens are chosen as an example of type I foam materials because of their good uniformity of the cell geometry. An extensive experimental study was carried out, where more attention was paid to their responses to dynamic loadings. Great enhancement of the stress-strain curve was observed in dynamic cases, and the energy absorption capacity is found to be several times higher than that of the commercial metal foams. Based on the experimental study, finite elemental simulations and theoretical modeling are also conducted, achieving good agreements and demonstrating the validities of those models. It is believed that the experimental, numerical and analytical results obtained in the present study will certainly deepen the understanding of the unsolved fundamental issues on the mechanical behavior of

Experimental validation of 3D printed material behaviors and their influence on the structural topology design

Science.gov (United States)

Yang, Kai Ke; Zhu, Ji Hong; Wang, Chuang; Jia, Dong Sheng; Song, Long Long; Zhang, Wei Hong

2018-05-01

The purpose of this paper is to investigate the structures achieved by topology optimization and their fabrications by 3D printing considering the particular features of material microstructures and macro mechanical performances. Combining Digital Image Correlation and Optical Microscope, this paper experimentally explored the anisotropies of stiffness and strength existing in the 3D printed polymer material using Stereolithography (SLA) and titanium material using Selective Laser Melting (SLM). The standard specimens and typical structures obtained by topology optimization were fabricated along different building directions. On the one hand, the experimental results of these SLA produced structures showed stable properties and obviously anisotropic rules in stiffness, ultimate strengths and places of fractures. Further structural designs were performed using topology optimization when the particular mechanical behaviors of SLA printed materials were considered, which resulted in better structural performances compared to the optimized designs using `ideal' isotropic material model. On the other hand, this paper tested the mechanical behaviors of SLM printed multiscale lattice structures which were fabricated using the same metal powder and the same machine. The structural stiffness values are generally similar while the strength behaviors show a difference, which are mainly due to the irregular surface quality of the tiny structural branches of the lattice. The above evidences clearly show that the consideration of the particular behaviors of 3D printed materials is therefore indispensable for structural design and optimization in order to improve the structural performance and strengthen their practical significance.

Experimental validation of 3D printed material behaviors and their influence on the structural topology design

Science.gov (United States)

Yang, Kai Ke; Zhu, Ji Hong; Wang, Chuang; Jia, Dong Sheng; Song, Long Long; Zhang, Wei Hong

2018-02-01

The purpose of this paper is to investigate the structures achieved by topology optimization and their fabrications by 3D printing considering the particular features of material microstructures and macro mechanical performances. Combining Digital Image Correlation and Optical Microscope, this paper experimentally explored the anisotropies of stiffness and strength existing in the 3D printed polymer material using Stereolithography (SLA) and titanium material using Selective Laser Melting (SLM). The standard specimens and typical structures obtained by topology optimization were fabricated along different building directions. On the one hand, the experimental results of these SLA produced structures showed stable properties and obviously anisotropic rules in stiffness, ultimate strengths and places of fractures. Further structural designs were performed using topology optimization when the particular mechanical behaviors of SLA printed materials were considered, which resulted in better structural performances compared to the optimized designs using `ideal' isotropic material model. On the other hand, this paper tested the mechanical behaviors of SLM printed multiscale lattice structures which were fabricated using the same metal powder and the same machine. The structural stiffness values are generally similar while the strength behaviors show a difference, which are mainly due to the irregular surface quality of the tiny structural branches of the lattice. The above evidences clearly show that the consideration of the particular behaviors of 3D printed materials is therefore indispensable for structural design and optimization in order to improve the structural performance and strengthen their practical significance.

Individual-Based Compulsive Sexual Behavior Scale: Its Development and Importance in Examining Compulsive Sexual Behavior.

Science.gov (United States)

Efrati, Yaniv; Mikulincer, Mario

2018-04-03

Compulsive sexual behavior comprises individual-based (e.g., sexual fantasies, compulsive sexual thoughts, masturbation) and partnered (e.g., interpersonal sexual conquests, repeated infidelity) facets. Most instruments for assessing compulsive sexual behavior, however, focus less on the individual-based facet and specifically on fantasies and compulsive thoughts. In the current research, we developed and validated an individual-based compulsive sexual behavior scale (I-CSB). In Study 1 (N = 492), the factorial structure of the I-CSB was examined. In Study 2 (N = 406), we assessed I-CSB's convergent validity. In Study 3 (N = 112), we examined whether the I-CSB differentiates between individuals who suffer from compulsive sexual behavior and those who do not. Results revealed a four-factor structure for individual-based compulsive sexual behavior that is associated with an intense inner conflict regarding sexuality (high arousal contrasting with high sexual anxiety), and that accounts for approximately 75% of the differences between people with compulsive sexual behavior and controls. Results are discussed in light of the need for a broader understanding of compulsive sexual behavior.

Studies on turbulence structure and liquid film behavior in annular two-phase flow flowing in a throat section

International Nuclear Information System (INIS)

Yoshida, Kenji; Miyabe, Masaya; Matsumoto, Tadayoshi; Kataoka, Isao; Ohmori, Shuichi; Mori, Michitsugu

2004-01-01

Experimental studies on turbulence structure and liquid film behavior in annular two-phase flow were carried out concerned with the steam injector systems for a next-generation nuclear reactor. In the steam injector, steam/water annular two-phase flow is formed at the mixing nozzle. To make an appropriate design for high-performance steam injector system, it is very important to accumulate the fundamental data of thermo-hydro dynamic characteristics of annular flow in the steam injector. Especially, the turbulence modification in multi-phase flow due to the phase interaction is one of the most important phenomena and has attracted research attention. In this study, the liquid film behavior and the resultant turbulence modification due to the phase interaction were investigated. The behavior of the interfacial waves on liquid film flow such as the ripple or disturbance waves were observed to make clear the interfacial velocity and the special structure of the interfacial waves by using the high-speed video camera and the digital camera. The measurements for gas-phase velocity profiles and turbulent intensity in annular flow passing through the throat section were precisely performed to investigate quantitatively the turbulent modification in annular flow by using the constant temperature hot-wire anemometer. The measurements for liquid film thickness by the electrode needle method were also carried out. (author)

Predictors of Behavior Factors of High School Students against Recycling

Science.gov (United States)

Cimen, Osman; Yilmaz, Mehmet

2016-01-01

This study aims to determine the variables that predict high school students' recycling behaviors. The study was designed as survey model. The study's sample consists of 203 students at a high school in Ankara. A recycling behavior scale developed by the researchers was used as a data collection tool. The scale has 3 dimensions: recycling…

Structural and Behavioral Correlates of HIV Infection among Pregnant Women in a Country with a Highly Generalized HIV Epidemic: A Cross-Sectional Study with a Probability Sample of Antenatal Care Facilities in Swaziland.

Science.gov (United States)

Lukhele, Bhekumusa Wellington; Techasrivichien, Teeranee; Suguimoto, S Pilar; Musumari, Patou Masika; El-Saaidi, Christina; Haumba, Samson; Tagutanazvo, Oslinah Buru; Ono-Kihara, Masako; Kihara, Masahiro

2016-01-01

HIV disproportionately affects women in Sub-Saharan Africa. Swaziland bears the highest HIV prevalence of 41% among pregnant women in this region. This heightened HIV-epidemic reflects the importance of context-specific interventions. Apart from routine HIV surveillance, studies that examine structural and behavioral factors associated with HIV infection among women may facilitate the revitalization of existing programs and provide insights to inform context-specific HIV prevention interventions. This cross-sectional study employed a two-stage random cluster sampling in ten antenatal health care facilities in the Hhohho region of Swaziland in August and September 2015. Participants were eligible for the study if they were 18 years or older and had tested for HIV. Self-administered tablet-based questionnaires were used to assess HIV risk factors. Of all eligible pregnant women, 827 (92.4%) participated, out of which 297 (35.9%) were self-reportedly HIV positive. Among structural factors, family function was not significantly associated with self-reported HIV positive status, while lower than high school educational attainment (AOR, 1.65; CI, 1.14-3.38; P = 0.008), and income below minimum wage (AOR, 1.81; CI, 1.09-3.01; P = 0.021) were significantly associated with self-reported HIV positive status. Behavioral factors significantly associated with reporting a positive HIV status included; ≥2 lifetime sexual partners (AOR, 3.16; CI, 2.00-5.00; PHIV/AIDS-related knowledge level was high but not associated to self-reported HIV status (P = 0.319). Structural and behavioral factors showed significant association with self-reported HIV infection among pregnant women in Swaziland while HIV/AIDS-related knowledge and family function did not. This suggests that HIV interventions should be reinforced taking into consideration these findings. The findings also suggest the importance of future research sensitive to the Swazi and African sociocultural contexts, especially

Hierarchical core-shell structure of ZnO nanorod@NiO/MoO₂ composite nanosheet arrays for high-performance supercapacitors.

Science.gov (United States)

Hou, Sucheng; Zhang, Guanhua; Zeng, Wei; Zhu, Jian; Gong, Feilong; Li, Feng; Duan, Huigao

2014-08-27

A hierarchical core-shell structure of ZnO nanorod@NiO/MoO2 composite nanosheet arrays on nickel foam substrate for high-performance supercapacitors was constructed by a two-step solution-based method involving two hydrothermal processes followed by a calcination treatment. Compared to one composed of pure NiO/MoO2 composite nanosheets, the hierarchical core-shell structure electrode displays better pseudocapacitive behaviors in 2 M KOH, including high areal specific capacitance values of 1.18 F cm(-2) at 5 mA cm(-2) and 0.6 F cm(-2) at 30 mA cm(-2) as well as relatively good rate capability at high current densities. Furthermore, it also shows remarkable cycle stability, remaining at 91.7% of the initial value even after 4000 cycles at a current density of 10 mA cm(-2). The enhanced pseudocapacitive behaviors are mainly due to the unique hierarchical core-shell structure and the synergistic effect of combining ZnO nanorod arrays and NiO/MoO2 composite nanosheets. This novel hierarchical core-shell structure shows promise for use in next-generation supercapacitors.

Profiles of classroom behavior in high schools: associations with teacher behavior management strategies and classroom composition.

Science.gov (United States)

Pas, Elise T; Cash, Anne H; O'Brennan, Lindsey; Debnam, Katrina J; Bradshaw, Catherine P

2015-04-01

Although there has been considerable attention to the issue of classroom management and processes in educational reform models, there has been relatively limited research on these factors in high schools. The current study utilized observational data from 1262 classrooms in 52 high schools to examine teacher classroom management strategies and ratings of student compliance, engagement, and social disruption. Latent profile analysis (LPA) was conducted to examine specific patterns of classroom-wide student behavior in relation to teachers' use of classroom management strategies and classroom composition. The LPA revealed three distinct classroom behavioral profiles where students consistently met behavioral expectations (71%), inconsistently met expectations (23%), and were noncompliant (6%). Analyses indicated a functional association between patterns of student behavior and teachers' classroom management. In classrooms where students consistently met expectations, teachers provided more opportunities to respond and less disapproval and reactive behavioral management. Classrooms with noncompliant students had teachers who used the most disapproval and reactive behavior management. In addition, classrooms characterized as consistent had fewer males and more White students than classrooms characterized by inconsistent and noncompliant behaviors. These findings highlight the link between student patterns of behavior and teacher classroom management and have important implications for screening and professional development. Copyright © 2014 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Microstructure and Wear Behavior of Atmospheric Plasma-Sprayed AlCoCrFeNiTi High-Entropy Alloy Coating

Science.gov (United States)

Tian, Li-Hui; Xiong, Wei; Liu, Chuan; Lu, Sheng; Fu, Ming

2016-12-01

Due to the advantages such as high strength, high hardness and good wear resistance, high-entropy alloys (HEAs) attracted more and more attentions in recent decades. However, most reports on HEAs were limited to bulk materials. Although a few of studies on atmospheric plasma-sprayed (APS) HEA coatings were carried out, the wear behavior, especially the high-temperature wear behavior of those coatings has not been investigated till now. Therefore, in this study, APS was employed to deposit AlCoCrFeNiTi high-entropy alloy coating using mechanically alloyed AlCoCrFeNiTi powder as the feedstock. The phase structure of the initial powder, the feedstock powder and the as-sprayed coating was examined by an x-ray diffractometer. The surface morphology of the feedstock powder and the microstructure of the as-sprayed coating were analyzed by field emission scanning electron microscopy and energy-dispersive spectroscopy. The bonding strength and the microhardness of the as-sprayed coating were tested. The wear behavior of the coating at 25, 500, 700 and 900 °C was investigated by analysis of the wear surface morphology and measurements of the volume wear rate and the coefficient of friction.

Health-promoting behaviors among female students in primary and secondary high school levels in Poldokhtar in 2014

Directory of Open Access Journals (Sweden)

2015-12-01

Full Text Available Background : Teenage girls health is more important due to multiple cultural and social reasons, the maturity characteristics of girls and their somatic and mental conditions of puberty and also their main role in fertility and its influence on a family life, makes a reduplicate importance on teenage girls health in comparison with boys. The purpose of this study was to investigate the health-promoting behaviors of female students in Poldokhtar. Materials and Methods: This descriptive cross-sectional study, was carried out on 427 high school female students selected using multiple step sampling method. Data were collected by a questionnaire (demographic questions, and standard health-promotion behaviors (HPLPII. Data were analyzed by t-test and ANOVA. Results: 421 questionnaires were completed. Average of general score of health-promoting behaviors was about 6.64 percent. Average score of different structures in students consisted of health responsibility, nutrition, physical activity and stress management were 7.68, 9.66, 2.58 and 8.56 percent respectively. Parental education, mother's occupation, family size, type of entertainment and body mass index had a significant relation with health-promoting behaviors (p<0.001. Conclusion: The results of this research showed that the sanitary behaviors of girl student in Poldokhtar has a moderate range. Stress management and physical activity had an inappropriate situation compared with two other structures and this makes more attention for more entries.

Investigating the degradation behavior under hot carrier stress for InGaZnO TFTs with symmetric and asymmetric structures

International Nuclear Information System (INIS)

Tsai, Ming-Yen; Chang, Ting-Chang; Chu, Ann-Kuo; Chen, Te-Chih; Hsieh, Tien-Yu; Chen, Yu-Te; Tsai, Wu-Wei; Chiang, Wen-Jen; Yan, Jing-Yi

2013-01-01

This letter studies the hot-carrier effect in indium–gallium–zinc oxide (IGZO) thin film transistors with symmetric and asymmetric source/drain structures. The different degradation behaviors after hot-carrier stress in symmetric and asymmetric source/drain devices indicate that different mechanisms dominate the degradation. Since the C–V measurement is highly sensitive to trap states compared to the I–V characterization, C–V curves are utilized to analyze the hot-carrier stress-induced trap state generation. Furthermore, the asymmetric C–V measurements C GD (gate-to-drain capacitance) and C GS (gate-to-source capacitance) are used to analyze the trap state in channel location. The asymmetric source/drain structure under hot-carrier stress induces an asymmetric electrical field and causes different degradation behaviors. In this work, the on-current and subthreshold swing (S.S.) degrade under low electrical field, whereas an apparent V t shift occurs under large electrical field. The different degradation behaviors indicate that trap states are generated under a low electrical field and the channel-hot-electron (CHE) effect occurs under a large electrical field. - Highlights: ► Asymmetric structure thin film transistors improve kick-back effect. ► Asymmetric structures under hot-carrier stress induce different degradation. ► Hot-carrier stress leads to capacitance–voltage curve distortion. ► Extra trap states are generated during hot-carrier stress

Seismic behavior and design of a primary shield structure consisting of steel-plate composite (SC) walls

Energy Technology Data Exchange (ETDEWEB)

Booth, Peter N., E-mail: boothpn@purdue.edu [Lyles School of Civil Engineering, Purdue University, W. Lafayette, IN (United States); Varma, Amit H., E-mail: ahvarma@purdue.edu [Lyles School of Civil Engineering, Purdue University, W. Lafayette, IN (United States); Sener, Kadir C., E-mail: ksener@purdue.edu [Lyles School of Civil Engineering, Purdue University, W. Lafayette, IN (United States); Mori, Kentaro, E-mail: kentaro_mori@mhi.co.jp [Mitsubishi Heavy Industries, Ltd, Kobe (Japan)

2015-12-15

This paper presents an analytical evaluation of the seismic behavior and design of a unique primary shield (PSW) structure consisting of steel-plate composite (SC) walls designed for a typical pressurized water reactor (PWR) nuclear power plant. Researchers in Japan have previously conducted a reduced (1/6th) scale test of a PSW structure to evaluate its seismic (lateral) load-deformation behavior. This paper presents the development and benchmarking of a detailed 3D nonlinear inelastic finite element (NIFE) model to predict the lateral load-deformation response and behavior of the 1/6th scale test structure. The PSW structure consists of thick SC wall segments with complex and irregular geometry that surround the central reactor vessel cavity. The wall segments have three layers of steel plates (one each on the interior and exterior surfaces and one embedded in the middle) that are anchored to the concrete infill with stud anchors. The results from the 3D NIFE analyses include: (i) the lateral load-deformation behavior of the PSW structure, (ii) the progression of yielding in the steel plates, concrete cracking, formation of compression struts, and (iii) the final failure mode. These results are compared and benchmarked using experimental measurements and observations reported by Shodo et al. (2003). The analytical results provide significant insight into the lateral behavior and strength of the PSW structure, and are used for developing a design approach. This design approach starts with ACI 349 code equations for reinforced concrete shear walls and modifies them for application to the PSW structure. A simplified 3D linear elastic finite element (LEFE) model of the PSW structure is also proposed as a conventional structural analysis tool for estimating the design force demands for various load combinations.

Seismic behavior and design of a primary shield structure consisting of steel-plate composite (SC) walls

International Nuclear Information System (INIS)

Booth, Peter N.; Varma, Amit H.; Sener, Kadir C.; Mori, Kentaro

2015-01-01

This paper presents an analytical evaluation of the seismic behavior and design of a unique primary shield (PSW) structure consisting of steel-plate composite (SC) walls designed for a typical pressurized water reactor (PWR) nuclear power plant. Researchers in Japan have previously conducted a reduced (1/6th) scale test of a PSW structure to evaluate its seismic (lateral) load-deformation behavior. This paper presents the development and benchmarking of a detailed 3D nonlinear inelastic finite element (NIFE) model to predict the lateral load-deformation response and behavior of the 1/6th scale test structure. The PSW structure consists of thick SC wall segments with complex and irregular geometry that surround the central reactor vessel cavity. The wall segments have three layers of steel plates (one each on the interior and exterior surfaces and one embedded in the middle) that are anchored to the concrete infill with stud anchors. The results from the 3D NIFE analyses include: (i) the lateral load-deformation behavior of the PSW structure, (ii) the progression of yielding in the steel plates, concrete cracking, formation of compression struts, and (iii) the final failure mode. These results are compared and benchmarked using experimental measurements and observations reported by Shodo et al. (2003). The analytical results provide significant insight into the lateral behavior and strength of the PSW structure, and are used for developing a design approach. This design approach starts with ACI 349 code equations for reinforced concrete shear walls and modifies them for application to the PSW structure. A simplified 3D linear elastic finite element (LEFE) model of the PSW structure is also proposed as a conventional structural analysis tool for estimating the design force demands for various load combinations.

Time-Dependent Behavior of High-Strength Kevlar and Vectran Webbing

Science.gov (United States)

Jones, Thomas C.; Doggett, William R.

2014-01-01

High-strength Kevlar and Vectran webbings are currently being used by both NASA and industry as the primary load-bearing structure in inflatable space habitation modules. The time-dependent behavior of high-strength webbing architectures is a vital area of research that is providing critical material data to guide a more robust design process for this class of structures. This paper details the results of a series of time-dependent tests on 1-inch wide webbing including an initial set of comparative tests between specimens that underwent realtime and accelerated creep at 65 and 70% of their ultimate tensile strength. Variability in the ultimate tensile strength of the webbings is investigated and compared with variability in the creep life response. Additional testing studied the effects of load and displacement rate, specimen length and the time-dependent effects of preconditioning the webbings. The creep test facilities, instrumentation and test procedures are also detailed. The accelerated creep tests display consistently longer times to failure than their real-time counterparts; however, several factors were identified that may contribute to the observed disparity. Test setup and instrumentation, grip type, loading scheme, thermal environment and accelerated test postprocessing along with material variability are among these factors. Their effects are discussed and future work is detailed for the exploration and elimination of some of these factors in order to achieve a higher fidelity comparison.

Finite element analysis of inelastic structural behavior

International Nuclear Information System (INIS)

Argyris, J.H.; Szimmat, J.; Willam, K.J.

1977-01-01

The paper describes recent achievements in the finite element analysis of inelastic material behavior. The main purpose is to examine the interaction of three disciplines; (i) the finite element formulation of large deformation problems in the light of a systematic linearization, (ii) the constitutive modelling of inelastic processes in the rate-dependent and rate-independent response regime and (iii) the numerical solution of nonlinear rate problems via incremental iteration techniques. In the first part, alternative finite element models are developed for the idealization of large deformation problems. A systematic approach is presented to linearize the field equations locally by an incremental procedure. The finite element formulation is then examined for the description of inelastic material processes. In the second part, nonlinear and inelastic material phenomena are classified and illustrated with representative examples of concrete and metal components. In particular, rate-dependent and rate-independent material behavior is examined and representative constitutive models are assessed for their mathematical characterization. Hypoelastic, elastoplastic and endochronic models are compared for the description rate-independent material phenomena. In the third part, the numerial solution of inelastic structural behavior is discussed. In this context, several incremental techniques are developed and compared for tracing the evolution of the inelastic process. The numerical procedures are examined with regard to stability and accuracy to assess the overall efficiency. The 'optimal' incremental technique is then contrasted with the computer storage requirements to retain the data for the 'memory-characteristics' of the constitutive model

Comparison study of inelastic analyses for high temperature structure subjected to cyclic creep loading

International Nuclear Information System (INIS)

Kim, J. B.; Lee, H. Y.; Lee, J. H.

2002-01-01

It is necessary to develop a reliable numerical analysis method to simulate the plasticity and creep behavior of LMR high temperature structures. Since general purpose finite element analysis codes such as ABAQUS and ANSYS provide various models for plastic hardening and creep equation of Norton's power law, it is possible to perform the separate iscoplasticity analysis. In this study, the high temperature structural analysis program(NONSTA-VP) implementing Chaboche's unified visco plasticity equation into ABAQUS has been developed and the viscoplastic response of the 316 SS plate having a circular hole subjected to a cyclic creep loading has been analyzed. The results among the separate visco plasticity analyses and the unified visco plasticity analysis using NONSTA-VP have been compared and the results from NONSTA-VP shows remarkable responses of stress relaxation and creep behavior during hold time compared to those from separate visco plasticity analyses. Also, it is anticipated to reduce the conservatism arising from using elastic approach for creep-fatigue damage analysis since the stress range and the strain range from the unified visco plasticity analysis has been greatly reduced compared to those from separate visco plasticity analyses and elastic analysis

A function-behavior-structure framework for quantification and reproduction of emotional haptic experience in using an electronic device

International Nuclear Information System (INIS)

Bae, Il Ju; Lee, Soo Hong; Ok, Hyung Seok; Lee, Jae In

2013-01-01

A user's haptic experience in using an electronic device is related to the continuous and dynamic variances of the structural state of the device. Since the changes of the structural component cause complex changes of the dynamics, it is difficult to predict the user's experience. We propose a function-behavior-structure framework to predict and improve the user's experience. The framework consists of the function layer model, the behavior layer model, and the structure layer model. Especially, the independent behavior model to the device is based on a physical phenomenon. Finally, an optimized structure which produces an ideal haptic experience for a cell phone is suggested.

Stochastic models for structured populations scaling limits and long time behavior

CERN Document Server

Meleard, Sylvie

2015-01-01

In this contribution, several probabilistic tools to study population dynamics are developed. The focus is on scaling limits of qualitatively different stochastic individual based models and the long time behavior of some classes of limiting processes. Structured population dynamics are modeled by measure-valued processes describing the individual behaviors and taking into account the demographic and mutational parameters, and possible interactions between individuals. Many quantitative parameters appear in these models and several relevant normalizations are considered, leading  to infinite-dimensional deterministic or stochastic large-population approximations. Biologically relevant questions are considered, such as extinction criteria, the effect of large birth events, the impact of  environmental catastrophes, the mutation-selection trade-off, recovery criteria in parasite infections, genealogical properties of a sample of individuals. These notes originated from a lecture series on Structured P...

Experimental Study on Temperature Behavior of SC Structures under Pure Bending

International Nuclear Information System (INIS)

Ham, K. W.; Lee, K. J.; Park, D. S.; Jeon, J. H.

2006-01-01

SC(Steel plate Concrete) module method uses steel plate instead of reinforcing bar and mold in existing RC structure. Steel plate modules are fabricated in advance, installed and poured with concrete in construction field, so construction period is remarkably shortened by SC module technique. In case of existence of temperature gap between internal and external structure surface such as spent fuel storage pool, thermal stress is taken place and as a result of it, structural strength is deteriorated. In this study, we designed three test specimens and several tests with or without temperature heating were conducted to evaluate temperature behavior of SC structures under pure bending loading condition

HTGR fuel behavior at very high temperature

International Nuclear Information System (INIS)

Kashimura, Satoru; Ogawa, Touru; Fukuda, Kousaku; Iwamoto, Kazumi

1986-03-01

Fuel behavior at very high temperature simulating abnormal transient of the reactor operation and accidents have been investigated on TRISO coating LEU oxide particle fuels at JAERI. The test simulating the abnormal transient was carried out by irradiation of loose coated particles above 1600 deg C. The irradiation test indicated that particle failure was principally caused by kernel migration. For simulation of the core heat-up accident, two experiments of out-of-pile heating were made. Survival temperature limits were measured and fuel performance at very high temperature were investigated by the heatings. Study on the fuel behavior under reactivity initiated accident was made by NSRR(Nuclear Safety Research Reactor) pulse irradiation, where maximum temperature was higher than 2800 deg C. It was found in the pulse irradiation experiments that the coated particles incorporated in the compacts did not so severely fail unlike the loose coated particles at ultra high temperature above 2800 deg C. In the former particles UO 2 material at the center of the kernel vaporized, leaving a spherical void. (author)

Peer Victimization and Suicidal Behaviors among High School Youth

Science.gov (United States)

Crepeau-Hobson, Franci; Leech, Nancy L.

2016-01-01

This study examined the association between various types of peer-directed violence and suicidal thoughts and behaviors among adolescents. A nationally representative sample of 15,425 high school students completed the 2011 Youth Risk Behavior Survey. All types of peer victimization (bullying, physical violence, and dating violence) were found to…

Characteristic behavior of underground and semi-underground structure at earthquake

International Nuclear Information System (INIS)

Sawada, Yoshihiro; Komada, Hiroya

1985-01-01

An appropriate earthquake-resistant repository design is required to ensure the safety of the radioactive wastes (shallow or deep ground disposal of low- and high-level wastes, respectively). It is particularly important to understand the propagation characteristics of seismic waves and the behaviors of underground hollow structures at the time of an earthquake. This report deals with seismologic observations of rock beds and undergound structures. The maximum acceleration deep under the ground is found to be about 1/2 - 1/3 of that at the ground surface or along the rock bed in the horizontal direction and about 1/1 - 1/2 in the longitudinal direction. A large attenuation cannot be expected in shallow ground. The decrease in displacement amplitude is small compared to that in acceleration. The attenuation effect is larger for a small earthquake and at a short hypocentral distance. The attenuation factor reaches a maximum at a depth of several tens of meters. The seismic spectrum under the ground is flatter than that at the surface. The maximum acceleration along the side wall of a cavity is almost the same as that in the surrounding rock bed. An underground cavity shows complicated phase characteristics at the time of a small earthquake at a short hypocentral distance. (Nogami, K.)

Experimental Study on Temperature Behavior of SSC (Stiffened Steel Plate Concrete) Structures

International Nuclear Information System (INIS)

Lee, K. J.; Ham, K. W.; Park, D. S.; Kwon, K. J.

2008-01-01

SSC(Stiffened Steel plate Concrete) module method uses steel plate instead of reinforcing bar and mold in existing RC structure. Steel plate modules are fabricated in advance, installed and poured with concrete in construction field, so construction period is remarkably shortened by SC module technique. In case of existence of temperature gap between internal and external structure surface such as containment building, thermal stress is taken place and as a result of it, structural strength is deteriorated. In this study, we designed two test specimens and several tests with temperature heating were conducted to evaluate temperature behavior of SSC structures and RC structure

Fast Food Consumption Behaviors in High-School Students based on the Theory of Planned Behavior (TPB)

OpenAIRE

Kamal Mirkarimi; Morteza Mansourian; Mohammad Javad Kabir; Rahman Berdi Ozouni- Davaji; Maryam Eri; Seyed Ghadir Hosseini; Mostafa Qorbani; Omid Safari; Babak Rastgari Mehr; Mehdi Noroozi; Abdurrahman Charkazi; Hossein Shahnazi

2016-01-01

Background: Studies report inappropriate snack and junk food consumption patterns in children and young adults in Iran. The current survey was aimed to explore fast food consumption behaviors in high-school students based on the Theory of Planned Behavior. Materials and Methods: A cross-sectional study was done among 500 high-school students. Samples were selected based on cluster sampling method at first and simple random at second. Data were collected using a researcher-made questionnaire. ...

Associations of Physical Activity and Sedentary Behaviors with Dietary Behaviors among US High School Students

Directory of Open Access Journals (Sweden)

Richard Lowry

2015-01-01

Full Text Available Background. Physical activity (PA, sedentary behaviors, and dietary behaviors are each associated with overweight and obesity among youth. However, the associations of PA and sedentary behaviors with dietary behaviors are complex and not well understood. Purpose. To describe the associations of PA and sedentary behaviors with dietary behaviors among a representative sample of US high school students. Methods. We analyzed data from the 2010 National Youth Physical Activity and Nutrition Study (NYPANS. Using logistic regression models which controlled for sex, race/ethnicity, grade, body weight status, and weight management goals, we compared dietary behaviors among students who did and did not meet national recommendations for PA and sedentary behaviors. Results. Students who participated in recommended levels of daily PA (DPA and muscle strengthening PA (MSPA were more likely than those who did not to eat fruits and vegetables. Students who exceeded recommended limits for television (TV and computer/video game (C/VG screen time were less likely than those who did not to consume fruits and vegetables and were more likely to consume fast food and sugar-sweetened beverages. Conclusions. Researchers may want to address PA, sedentary behaviors, and dietary behaviors jointly when developing health promotion and obesity prevention programs for youth.

Modeling bistable behaviors in morphing structures through finite element simulations.

Science.gov (United States)

Guo, Qiaohang; Zheng, Huang; Chen, Wenzhe; Chen, Zi

2014-01-01

Bistable structures, exemplified by the Venus flytrap and slap bracelets, can transit between different configurations upon certain external stimulation. Here we study, through three-dimensional finite element simulations, the bistable behaviors in elastic plates in the absence of terminate loads, but with pre-strains in one (or both) of the two composite layers. Both the scenarios with and without a given geometric mis-orientation angle are investigated, the results of which are consistent with recent theoretical and experimental studies. This work can open ample venues for programmable designs of plant/shell structures with large deformations, with applications in designing bio-inspired robotics for biomedical research and morphing/deployable structures in aerospace engineering.

Structural phase transition and elastic properties of AnAs (An= Th, U, Np, Pu) compounds at high pressure

International Nuclear Information System (INIS)

Aynyas, Mahendra; Arya, B.S.; Srivastava, Vipul; Sanyal, Sankar P.

2006-01-01

The high pressure behavior and pressure induced structural phase transition of mono arsenides (AnAs; An = Th, U, Np, Pu) have been investigated by using a three body interaction potential (TBI). This method has been found quite satisfactory in the case of other Rare-Earth compounds. The calculated compression curves of mono-arsenides obtained so have been compared with high pressure X-ray diffraction work. The theoretically predicted phase transition pressure and other structural properties for these compounds agree reasonably well with the measured values. (author)

High-cycle fatigue behavior of ultrafine-grained austenitic stainless and TWIP steels

Energy Technology Data Exchange (ETDEWEB)

Hamada, A.S. [Materials Engineering Laboratory (4KOMT), Box 4200, University of Oulu, 90014 Oulu (Finland); Metallurgical and Materials Engineering Department, Faculty of Petroleum and Mining Engineering, Suez Canal University, Box 43721, Suez (Egypt); Karjalainen, L.P., E-mail: pentti.karjalainen@oulu.fi [Materials Engineering Laboratory (4KOMT), Box 4200, University of Oulu, 90014 Oulu (Finland)

2010-08-20

High-cycle fatigue behavior of ultrafine-grained (UFG) 17Cr-7Ni Type 301LN austenitic stainless and high-Mn Fe-22Mn-0.6C TWIP steels were investigated in a reversed plane bending fatigue and compared to the behavior of steels with conventional coarse grain (CG) size. Optical, scanning and transmission electron microscopy were used to examine fatigue damage mechanisms. Testing showed that the fatigue limits leading to fatigue life beyond 4 x 10{sup 6} cycles were about 630 MPa for 301LN while being 560 MPa for TWIP steel, and being 0.59 and 0.5 of the tensile strength respectively. The CG counterparts were measured to have the fatigue limits of 350 and 400 MPa. The primary damage caused by fatigue took place by grain boundary cracking in UFG 301LN, while slip band cracking occurred in CG 301LN. However, in the case of TWIP steel, the fatigue damage mechanism is similar in spite of the grain size. In the course of cycling neither the formation of a martensite structure nor mechanical twinning occurs, but intense slip bands are created with extrusions and intrusions. Fatigue crack initiates preferentially on grain and twin boundaries, and especially in the intersection sites of slip bands and boundaries.

[Unhealthy behavior associated with the development of high blood pressure in adolescents].

Science.gov (United States)

Sánchez-Zamorano, Luisa María; Burguete-García, Ana Isabel; Flores-Sánchez, Guillermo; Salmerón-Castro, Jorge; Lazcano-Ponce, Eduardo C; Diaz-Benitez, Cinthya E

2017-04-03

This article aims to evaluate the association between unhealthy behavior pattern and prevalence and incidence of high blood pressure in adolescents. Based on data from a cohort study with a baseline population of 2,813 adolescents enrolled in a public school system, the study measured the baseline prevalence and incidence of high blood pressure as a function of smoking, alcohol and illegal drug use, and physical activity. These variables were used to build a model called "unhealthy behavior pattern", and its relationship was evaluated in relation to high blood pressure in adolescents, using multiple logistic regression models. Prevalence of high blood pressure was 8.67%. Accumulated incidence of high blood pressure was 7.58%. In the multivariate analysis of high blood pressure adjusted by degree of adiposity, there was an association with the unhealthy behavior pattern in males (OR = 3.13; 95%CI: 1.67-5.84). The association between incidence of high blood pressure and unhealthy behavior pattern was observed in females (OR = 2.34; 95%CI: 1.11-4.95). In conclusion, high blood pressure is present in the adolescent population, associated with unhealthy behaviors like smoking, alcohol and illegal drug use, and physical inactivity, independently of the degree of adiposity.

Dietary differentiation and the evolution of population genetic structure in a highly mobile carnivore.

Directory of Open Access Journals (Sweden)

Małgorzata Pilot

Full Text Available Recent studies on highly mobile carnivores revealed cryptic population genetic structures correlated to transitions in habitat types and prey species composition. This led to the hypothesis that natal-habitat-biased dispersal may be responsible for generating population genetic structure. However, direct evidence for the concordant ecological and genetic differentiation between populations of highly mobile mammals is rare. To address this we analyzed stable isotope profiles (δ(13C and δ(15N values for Eastern European wolves (Canis lupus as a quantifiable proxy measure of diet for individuals that had been genotyped in an earlier study (showing cryptic genetic structure, to provide a quantitative assessment of the relationship between individual foraging behavior and genotype. We found a significant correlation between genetic distances and dietary differentiation (explaining 46% of the variation in both the marginal test and crucially, when geographic distance was accounted for as a co-variable. These results, interpreted in the context of other possible mechanisms such as allopatry and isolation by distance, reinforce earlier studies suggesting that diet and associated habitat choice are influencing the structuring of populations in highly mobile carnivores.

A function-behavior-structure framework for quantification and reproduction of emotional haptic experience in using an electronic device

Energy Technology Data Exchange (ETDEWEB)

Bae, Il Ju; Lee, Soo Hong [Yonsei University, Seoul (Korea, Republic of); Ok, Hyung Seok; Lee, Jae In [LG Electronics Inc, Seoul (Korea, Republic of)

2013-08-15

A user's haptic experience in using an electronic device is related to the continuous and dynamic variances of the structural state of the device. Since the changes of the structural component cause complex changes of the dynamics, it is difficult to predict the user's experience. We propose a function-behavior-structure framework to predict and improve the user's experience. The framework consists of the function layer model, the behavior layer model, and the structure layer model. Especially, the independent behavior model to the device is based on a physical phenomenon. Finally, an optimized structure which produces an ideal haptic experience for a cell phone is suggested.

Single-source-precursor Synthesis and High-temperature Behavior of SiC Ceramics Containing Boron

Science.gov (United States)

Gui, Miaomiao; Fang, Yunhui; Yu, Zhaoju

2014-12-01

In this paper, a hyperbranched polyborocarbosilane (HPBCS) was prepared by a one-pot synthesis with Cl2Si(CH3)CH2Cl, Cl3SiCH2Cl and BCl3 as the starting materials. The obtained HPBCS was characterized by GPC, FT-IR and NMR, and was confirmed to have hyperbranched structures. The thermal property of the resulting HPBCS was investigated by TGA. The ceramic yield of the HPBCS is about 84% and that of the counterpart hyperbranched hydridopolycarbosilane is only 45%, indicating that the introduction of boron into the preceramic polymer significantly improved the ceramic yield. With the polymer-derived ceramic route, the final ceramics were annealed at 1800 °C in argon atmosphere for 2 h in order to characterize the microstructure and to evaluate the high-temperature behavior. The final ceramic microstructure was studied by XRD and SEM, indicating that the introduction of boron dramatically inhibits SiC crystallization. The boron-containing SiC ceramic shows excellent high-temperature behavior against decomposition and crystallization at 1800 °C.

Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

Directory of Open Access Journals (Sweden)

Long Chen

2016-01-01

Full Text Available This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

SCC crack propagation behavior in 316L weld metal under high temperature water

International Nuclear Information System (INIS)

Nakade, Katsuyuki; Hirasaki, Toshifumi; Suzuki, Shunichi; Takamori, Kenro; Kumagai, Katsuhiko; Tanaka, Yoshihiko; Umeoka, Kuniyoshi

2008-01-01

Intergranular stress corrosion cracking (SCC) of 316L weld metal is of concern to the BWR plants. PLR pipes in commercial BWR plants have shown SCC in almost HAZ area in high temperature water, whereas, SCC has been arrested around fusion boundary for long time in the actual PLR pipe. The SCC behavior could be characterized in terms of dendrite direction, which was defined as the angle between dendrite growth direction and macro-SCC direction. In this study, the relationship between dendrite growth direction and macro-SCC direction was clearly showed on the fracture surface. The relative large difference of SCC susceptibility of 316L HAZ and weld metal was observed on the fracture surface. In the case of 0 degree, SCC has rapidly propagated into the weld metal parallel to the dendrite structure. In the case of more than 30 degree SCC direction, SCC was arrested around fusion area, and 60 degree SCC was drastically arrested around the fusion area. The large inclined dendrite structure for SCC is highly resistant to SCC. (author)

Investigation of the structural behavior of the blades of a darrieus wind turbine†

Science.gov (United States)

Rosen, A.; Abramovich, H.

1985-06-01

A theoretical model in which account is taken of the non-linear, non-planar structural behavior of the curved blades of a Darrieus wind turbine is described. This model is simpler and needs less computational effort than some other models, but is still accurate enough for most engineering purposes. By using the present method, it is possible to treat any blade geometry, any structural, mass and aerodynamic blade properties distribution and any combination of boundary conditions. The model is used in order to calculate the blade behavior under the influence of concentrated loads, gravity loads and centrifugal loads. In order to verify the theoretical model, predictions are compared with experimental results which are obtained from tests with small models of curved blades. Usually the agreement between the theoretical and experimental results is very good. The influence of different parameters on blade behavior is presented and discussed.

High Risk Behaviors in Marine Mammals: Linking Behavioral Responses to Anthropogenic Disturbance to Biological Consequences

Science.gov (United States)

2015-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. High Risk Behaviors in Marine Mammals : Linking...comprehensive evaluation of biological safety zones for diving marine mammals . In this way we intend to identify those marine mammal species or specific...improving the protection of marine mammals during naval operations. OBJECTIVES We are testing the hypothesis that extreme behaviors requiring

Risky business: Behaviors associated with indoor tanning in US high school students

OpenAIRE

Chapman, Stephanie; Ashack, Kurt; Bell, Eric; Sendelweck, Myra Ann; Dellavalle, Robert

2017-01-01

Background: Understanding of associations between indoor tanning and risky health related behaviors such as sexual activity and substance abuse among high school students across the United States is incomplete. Objective: To identify risky health related behaviors among high school students utilizing indoor tanning and analyze differences between state specific data. Methods: Results from the Youth Risk Behavior Surveillance System (YRBSS) 2013 in...

Corrosion behavior of Ni-based structural materials for electrolytic reduction in lithium molten salt

International Nuclear Information System (INIS)

Cho, Soo Haeng; Park, Sung Bin; Lee, Jong Hyeon; Hur, Jin Mok; Lee, Han Soo

2011-01-01

In this study, the corrosion behavior of new Ni-based structural materials was studied for electrolytic reduction after exposure to LiCl-Li 2 O molten salt at 650 deg. C for 24-216 h under an oxidizing atmosphere. The new alloys with Ni, Cr, Al, Si, and Nb as the major components were melted at 1700 deg. C under an inert atmosphere. The melt was poured into a preheated metallic mold to prepare an as-cast alloy. The corrosion products and fine structures of the corroded specimens were characterized by scanning electron microscope (SEM), Energy Dispersive X-ray Spectroscope (EDS), and X-ray diffraction (XRD). The corrosion products of as cast and heat treated low Si/high Ti alloys were Cr 2 O 3 , NiCr 2 O 4 , Ni, NiO, and (Al,Nb,Ti)O 2 ; those of as cast and heat treated high Si/low Ti alloys were Cr 2 O 3 , NiCr 2 O 4 , Ni, and NiO. The corrosion layers of as cast and heat treated low Si/high Ti alloys were continuous and dense. However, those of as cast and heat treated high Si/low Ti alloys were discontinuous and cracked. Heat treated low Si/high Ti alloy showed the highest corrosion resistance among the examined alloys. The superior corrosion resistance of the heat treated low Si/high Ti alloy was attributed to the addition of an appropriate amount of Si, and the metallurgical evaluations were performed systematically.

The Geography of Sexual Orientation: Structural Stigma and Sexual Attraction, Behavior, and Identity Among Men Who Have Sex with Men Across 38 European Countries.

Science.gov (United States)

Pachankis, John E; Hatzenbuehler, Mark L; Mirandola, Massimo; Weatherburn, Peter; Berg, Rigmor C; Marcus, Ulrich; Schmidt, Axel J

2017-07-01

While the prevalence of sexual identities and behaviors of men who have sex with men (MSM) varies across countries, no study has examined country-level structural stigma toward sexual minorities as a correlate of this variation. Drawing on emerging support for the context-dependent nature of MSM's open sexual self-identification cross-nationally, we examined country-level structural stigma as a key correlate of the geographic variation in MSM's sexual attraction, behavior, and identity, and concordance across these factors. Data come from the European MSM Internet Survey, a multi-national dataset containing a multi-component assessment of sexual orientation administered across 38 European countries (N = 174,209). Country-level stigma was assessed using a combination of national laws and policies affecting sexual minorities and a measure of attitudes toward sexual minorities held by the citizens of each country. Results demonstrate that in more stigmatizing countries, MSM were significantly more likely to report bisexual/heterosexual attractions, behaviors, and identities, and significantly less likely to report concordance across these factors, than in less stigmatizing countries. Settlement size moderated associations between country-level structural stigma and odds of bisexual/heterosexual attraction and behavior, such that MSM living in sparsely populated locales within high-structural stigma countries were the most likely to report bisexual or heterosexual behaviors and attractions. While previous research has demonstrated associations between structural stigma and adverse physical and mental health outcomes among sexual minorities, this study was the first to show that structural stigma was also a key correlate not only of sexual orientation identification, but also of MSM's sexual behavior and even attraction. Findings have implications for understanding the ontology of MSM's sexuality and suggest that a comprehensive picture of MSM's sexuality will come

Family Structure Changes and Children's Health, Behavior, and Educational Outcomes

DEFF Research Database (Denmark)

Rasmussen, Astrid Würtz

More and more children do not grow up in traditional nuclear families. Instead they grow up in single parent households or in families with a step-parent. Hence it is important to improve our understanding of the impact of "shocks" in family structure due to parental relationship dissolution...... on children. In this study I empirically test whether children are traumatized both in the short and the long run by shocks in the family structure during childhood. I focus on educational, behavioral, and health outcomes. A population sample of Danish children born in January to May 1983, 1984, and 1985...... is used for the analysis. The empirical cross-sectional analysis indicates a negative relation between the number of family structure changes and children.s educational outcomes. Children experiencing many family structure changes also seem to have worse health outcomes....

Unique cold-crystallization behavior and kinetics of biodegradable poly[(butylene succinate)-co adipate] nanocomposites: a high speed differential scanning calorimetry study

CSIR Research Space (South Africa)

Bandyopadhyay, J

2014-08-01

Full Text Available . The effect of such structural changes on the cold-crystallization behavior and kinetics of PBSANCs were investigated using a high-speed DSC. Surprisingly, the DSC thermograms revealed that the characteristic cold-crystallization peak of neat PBSA shifts...

Neutron star evolution and the structure of matter at high density

International Nuclear Information System (INIS)

Soyeur, Madeleine.

1981-09-01

The structure and properties of neutron stars are determined by the state of cold nuclear matter at high density. In order to investigate the behavior of matter inside neutron stars, observables sensitive to their internal structure have to be calculated and confronted to observations. The thermal radiation of neutron stars seems to be a good candidate to be such observable. It can be shown that the neutrino luminosity of neutron stars, responsible for their cooling in the early stages of their evolution is strongly dependent on possible phase transitions to superfluid nucleons, to pion condensation or to quark matter. The specific heat of matter is also not the same in the various phases expected at high density and is particularly sensitive to the nucleon superfluidity. At present, both the theoretical estimates and the observations of the thermal properties of neutron stars are still quite preliminary. In particular, large uncertainties due to possible reheating mechanisms and magnetic field effects make the theoretical interpretation of the steady radiation of pulsars quite difficult

Disciplining behavior of dog owners in problem situations: The factorial structure

NARCIS (Netherlands)

Ben Michael-Steinberg, Judith; Korzilius, H.P.L.M.; Vossen, J.M.H.; Felling, A.J.A.

2000-01-01

The purpose of the study was to investigate the magnitude and structure of situation-specific owner emotions and behavioral reactions in problematic situations involving a dog. The following questions were addressed: 1. What is the magnitude of situation-specific owner emotions and reactions in a

Genotyping-By-Sequencing (GBS) Detects Genetic Structure and Confirms Behavioral QTL in Tame and Aggressive Foxes (Vulpes vulpes).

Science.gov (United States)

Johnson, Jennifer L; Wittgenstein, Helena; Mitchell, Sharon E; Hyma, Katie E; Temnykh, Svetlana V; Kharlamova, Anastasiya V; Gulevich, Rimma G; Vladimirova, Anastasiya V; Fong, Hiu Wa Flora; Acland, Gregory M; Trut, Lyudmila N; Kukekova, Anna V

2015-01-01

The silver fox (Vulpes vulpes) offers a novel model for studying the genetics of social behavior and animal domestication. Selection of foxes, separately, for tame and for aggressive behavior has yielded two strains with markedly different, genetically determined, behavioral phenotypes. Tame strain foxes are eager to establish human contact while foxes from the aggressive strain are aggressive and difficult to handle. These strains have been maintained as separate outbred lines for over 40 generations but their genetic structure has not been previously investigated. We applied a genotyping-by-sequencing (GBS) approach to provide insights into the genetic composition of these fox populations. Sequence analysis of EcoT22I genomic libraries of tame and aggressive foxes identified 48,294 high quality SNPs. Population structure analysis revealed genetic divergence between the two strains and more diversity in the aggressive strain than in the tame one. Significant differences in allele frequency between the strains were identified for 68 SNPs. Three of these SNPs were located on fox chromosome 14 within an interval of a previously identified behavioral QTL, further supporting the importance of this region for behavior. The GBS SNP data confirmed that significant genetic diversity has been preserved in both fox populations despite many years of selective breeding. Analysis of SNP allele frequencies in the two populations identified several regions of genetic divergence between the tame and aggressive foxes, some of which may represent targets of selection for behavior. The GBS protocol used in this study significantly expanded genomic resources for the fox, and can be adapted for SNP discovery and genotyping in other canid species.

Abnormalities in brain structure and behavior in GSK-3alpha mutant mice

Directory of Open Access Journals (Sweden)

Kaidanovich-Beilin Oksana

2009-11-01

Full Text Available Abstract Background Glycogen synthase kinase-3 (GSK-3 is a widely expressed and highly conserved serine/threonine protein kinase encoded by two genes that generate two related proteins: GSK-3α and GSK-3β. Mice lacking a functional GSK-3α gene were engineered in our laboratory; they are viable and display insulin sensitivity. In this study, we have characterized brain functions of GSK-3α KO mice by using a well-established battery of behavioral tests together with neurochemical and neuroanatomical analysis. Results Similar to the previously described behaviours of GSK-3β+/-mice, GSK-3α mutants display decreased exploratory activity, decreased immobility time and reduced aggressive behavior. However, genetic inactivation of the GSK-3α gene was associated with: decreased locomotion and impaired motor coordination, increased grooming activity, loss of social motivation and novelty; enhanced sensorimotor gating and impaired associated memory and coordination. GSK-3α KO mice exhibited a deficit in fear conditioning, however memory formation as assessed by a passive avoidance test was normal, suggesting that the animals are sensitized for active avoidance of a highly aversive stimulus in the fear-conditioning paradigm. Changes in cerebellar structure and function were observed in mutant mice along with a significant decrease of the number and size of Purkinje cells. Conclusion Taken together, these data support a role for the GSK-3α gene in CNS functioning and possible involvement in the development of psychiatric disorders.

The structural properties of Zr-based bulk metallic glasses subjected to high pressure torsion at different temperatures

International Nuclear Information System (INIS)

Boltynjuk, E. V.; Ubyivovk, E. V.; Kshumanev, A. M.; Gunderov, D. V.; Lukianov, A. V.; Bednarz, A.; Valiev, R. Z.

2016-01-01

The structural properties of a Zr_6_2Cu_2_2Al_1_0Fe_5Dy_1 bulk metallic glasses were investigated. Cylindrical rods of the Zr_6_2Cu_2_2Al_1_0Fe_5Dy_1 BMG were subjected to high pressure torsion at temperatures of 20°C and 150°C. X-ray diffraction, transmission electron microscopy were used to determine peculiarities of the modified structure. Analysis of fracture surfaces, nanohardness measurements were conducted to investigate the influence of structural changes on mechanical behavior of processed samples.

Anomalous High-Energy Waterfall-Like Electronic Structure in 5 d Transition Metal Oxide Sr2IrO4 with a Strong Spin-Orbit Coupling

Science.gov (United States)

Liu, Yan; Yu, Li; Jia, Xiaowen; Zhao, Jianzhou; Weng, Hongming; Peng, Yingying; Chen, Chaoyu; Xie, Zhuojin; Mou, Daixiang; He, Junfeng; Liu, Xu; Feng, Ya; Yi, Hemian; Zhao, Lin; Liu, Guodong; He, Shaolong; Dong, Xiaoli; Zhang, Jun; Xu, Zuyan; Chen, Chuangtian; Cao, Gang; Dai, Xi; Fang, Zhong; Zhou, X. J.

2015-08-01

The low energy electronic structure of Sr2IrO4 has been well studied and understood in terms of an effective Jeff = 1/2 Mott insulator model. However, little work has been done in studying its high energy electronic behaviors. Here we report a new observation of the anomalous high energy electronic structure in Sr2IrO4. By taking high-resolution angle-resolved photoemission measurements on Sr2IrO4 over a wide energy range, we have revealed for the first time that the high energy electronic structures show unusual nearly-vertical bands that extend over a large energy range. Such anomalous high energy behaviors resemble the high energy waterfall features observed in the cuprate superconductors. While strong electron correlation plays an important role in producing high energy waterfall features in the cuprate superconductors, the revelation of the high energy anomalies in Sr2IrO4, which exhibits strong spin-orbit coupling and a moderate electron correlation, points to an unknown and novel route in generating exotic electronic excitations.

Anomalous High-Energy Waterfall-Like Electronic Structure in 5 d Transition Metal Oxide Sr2IrO4 with a Strong Spin-Orbit Coupling.

Science.gov (United States)

Liu, Yan; Yu, Li; Jia, Xiaowen; Zhao, Jianzhou; Weng, Hongming; Peng, Yingying; Chen, Chaoyu; Xie, Zhuojin; Mou, Daixiang; He, Junfeng; Liu, Xu; Feng, Ya; Yi, Hemian; Zhao, Lin; Liu, Guodong; He, Shaolong; Dong, Xiaoli; Zhang, Jun; Xu, Zuyan; Chen, Chuangtian; Cao, Gang; Dai, Xi; Fang, Zhong; Zhou, X J

2015-08-12

The low energy electronic structure of Sr2IrO4 has been well studied and understood in terms of an effective Jeff = 1/2 Mott insulator model. However, little work has been done in studying its high energy electronic behaviors. Here we report a new observation of the anomalous high energy electronic structure in Sr2IrO4. By taking high-resolution angle-resolved photoemission measurements on Sr2IrO4 over a wide energy range, we have revealed for the first time that the high energy electronic structures show unusual nearly-vertical bands that extend over a large energy range. Such anomalous high energy behaviors resemble the high energy waterfall features observed in the cuprate superconductors. While strong electron correlation plays an important role in producing high energy waterfall features in the cuprate superconductors, the revelation of the high energy anomalies in Sr2IrO4, which exhibits strong spin-orbit coupling and a moderate electron correlation, points to an unknown and novel route in generating exotic electronic excitations.

Advanced High Temperature Structural Seals

Science.gov (United States)

Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark

2002-10-01

This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.

Structure, electronic properties, and aggregation behavior of hydroxylated carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

López-Oyama, A. B.; Silva-Molina, R. A.; Ruíz-García, J.; Guirado-López, R. A., E-mail: guirado@ifisica.uaslp.mx [Instituto de Física “Manuel Sandoval Vallarta,” Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, San Luis Potosí (Mexico); Gámez-Corrales, R. [Departamento de Física, Universidad de Sonora, Apartado Postal 5-088, 83190, Hermosillo, Sonora (Mexico)

2014-11-07

We present a combined experimental and theoretical study to analyze the structure, electronic properties, and aggregation behavior of hydroxylated multiwalled carbon nanotubes (OH–MWCNT). Our MWCNTs have average diameters of ∼2 nm, lengths of approximately 100–300 nm, and a hydroxyl surface coverage θ∼0.1. When deposited on the air/water interface the OH–MWCNTs are partially soluble and the floating units interact and link with each other forming extended foam-like carbon networks. Surface pressure-area isotherms of the nanotube films are performed using the Langmuir balance method at different equilibration times. The films are transferred into a mica substrate and atomic force microscopy images show that the foam like structure is preserved and reveals fine details of their microstructure. Density functional theory calculations performed on model hydroxylated carbon nanotubes show that low energy atomic configurations are found when the OH groups form molecular islands on the nanotube's surface. This patchy behavior for the OH species is expected to produce nanotubes having reduced wettabilities, in line with experimental observations. OH doping yields nanotubes having small HOMO–LUMO energy gaps and generates a nanotube → OH direction for the charge transfer leading to the existence of more hole carriers in the structures. Our synthesized OH–MWCNTs might have promising applications.

Behavior and ultimate strength of an inner concrete structure of a nuclear reactor building subjected to thermal and seismic loads

International Nuclear Information System (INIS)

Omatsuzawa, K.; Suzuki, Y.; Sato, M.; Takeda, T.; Yamaguchi, T.; Yoshioka, K.; Nakayama, T.; Furuya, N.; Kawaguchi, T.; Koike, K.; Naganuma, K.

1987-01-01

Heating tests and heating-plus-seismic-loading tests at high temperature (T max = 175 0 C) were conducted using various concrete structural members such as beams, cylindrical walls, H-section walls, and 1/10-scale models of the inner concrete (I/C) structure in a fast breeder reactor (FBR) building. Concrete subjected to high temperature exceeding 100 0 C has a tendency to have lower Young's modulus and to shrink. As these material constants are temperature-dependent, the thermal stress occurring within the concrete structure is smaller than the values usually obtained by normal crack analysis methods. Although thermal stresses and cracks exert marked influences on the behaviors of the structures during the earlier stages of loading, they hardly affect the ultimate bending and shear strengths. Specifically, as a result of I/C model tests, it was made clear that the ultimate strength of the structure is considerably greater than the design loads under combined thermal and seismic loading conditions. (orig./HP)

Behavior Disorders Prevalence in High School Students in Hamedan Province

Directory of Open Access Journals (Sweden)

Ali Reza Zolfaghari

2014-04-01

Full Text Available Objective: Behavioral disorders of childhood and adolescence represent a range of problems and Its prevalence varies in different parts of Iran and the world. Knowledge of them is essential to the prevention, treatment and rehabilitation of patients. The aim of this survey is assessment of behavior disorders prevalence in high school students in Hamedan province. Materials & Methods: In this descriptive and cross sectional study, 500 boy and girl students were selected from Hamedan high schools by multistep cluster sampling, based on region and gender. Data were gathered by Achenbach experience questionnaire (YSR form and analyzed by Friedman and independent T tests. Results: The findings showed that prevalence of behavioral problems among students in the province is 10 percent and it was higher in girls than boys. Most disorders were withdrawal disorder / anxiety and attention problems and somatization disorder was the least problem. Conclusion: Prevalence of behavior disorders in Hamedan province compared to other studies is moderate, but the behavior disorders prevalence of boys and girls are different from other researchs.

The effects of behavioral and structural assumptions in artificial stock market

Science.gov (United States)

Liu, Xinghua; Gregor, Shirley; Yang, Jianmei

2008-04-01

Recent literature has developed the conjecture that important statistical features of stock price series, such as the fat tails phenomenon, may depend mainly on the market microstructure. This conjecture motivated us to investigate the roles of both the market microstructure and agent behavior with respect to high-frequency returns and daily returns. We developed two simple models to investigate this issue. The first one is a stochastic model with a clearing house microstructure and a population of zero-intelligence agents. The second one has more behavioral assumptions based on Minority Game and also has a clearing house microstructure. With the first model we found that a characteristic of the clearing house microstructure, namely the clearing frequency, can explain fat tail, excess volatility and autocorrelation phenomena of high-frequency returns. However, this feature does not cause the same phenomena in daily returns. So the Stylized Facts of daily returns depend mainly on the agents’ behavior. With the second model we investigated the effects of behavioral assumptions on daily returns. Our study implicates that the aspects which are responsible for generating the stylized facts of high-frequency returns and daily returns are different.

Tensile and high cycle fatigue behaviors of high-Mn steels at 298 and 110 K

Energy Technology Data Exchange (ETDEWEB)

Seo, Wongyu; Jeong, Daeho; Sung, Hyokyung; Kim, Sangshik, E-mail: sang@gnu.ac.kr

2017-02-15

Tensile and high cycle fatigue behaviors of high-Mn austenitic steels, including 25Mn, 25Mn0.2Al, 25Mn0.5Cu, 24Mn4Cr, 22Mn3Cr and 16Mn2Al specimens, were investigated at 298 and 110 K. Depending on the alloying elements, tensile ductility of high-Mn steels either increased or decreased with decreasing temperature from 298 to 110 K. Reasonable correlation between the tendency for martensitic tranformation, the critical twinning stress and the percent change in tensile elongation suggested that tensile deformation of high-Mn steels was strongly influenced by SFE determining TRIP and TWIP effects. Tensile strength was the most important parameter in determining the resistance to high cycle fatigue of high-Mn steels with an exceptional work hardening capability at room and cryogenic temperatures. The fatigue crack nucleation mechanism in high-Mn steels did not vary with decreasing tempertature, except Cr-added specimens with grain boundary cracking at 298 K and slip band cracking at 110 K. The EBSD (electron backscatter diffraction) analyses suggested that the deformation mechanism under fatigue loading was significantly different from tensile deformation which could be affected by TRIP and TWIP effects. - Highlights: •The resistances to HCF of various high-Mn steels were measured. •The variables affecting tensile and HCF behaviors of high-Mn steels were assessed. •The relationship between tensile and the HCF behaviors of high-Mn steels was established.

Family Structure Changes and Children's Health, Behavior, and Educational Outcomes

DEFF Research Database (Denmark)

Rasmussen, Astrid Würtz

More and more children do not grow up in traditional nuclear families. Instead they grow up in single parent households or in families with a step-parent. Hence it is important to improve our understanding of the impact of 'shocks' in family structure due to parental relationship dissolution...... on children. In this study I empirically test whether children are traumatized by shocks in the family structure during childhood. I focus on both educational, behavioral, and health outcomes. A population sample of Danish children born in January to May 1983, 1984, and 1985 is used for the analysis...

Compression Behavior of Confined Columns with High-Volume Fly Ash Concrete

Directory of Open Access Journals (Sweden)

Sung-Won Yoo

2017-01-01

Full Text Available The use of fly ash in ordinary concrete provides practical benefits to concrete structures, such as a gain in long-term strength, reduced hydration heat, improved resistance to chloride, and enhanced workability. However, few studies with high-volume fly ash (HVFA concrete have been conducted that focus on the structural applications such as a column. Thus, there is a need to promote field applications of HVFA concrete as a sustainable construction material. To this end, this study investigated the compressive behavior of reinforced concrete columns that contain HVFA with a 50 percent replacement rate. Six columns were fabricated for this study. The study variables were the HVFA replacement rate, tied steel ratio, and tie steel spacing. The computed ultimate strength by the American Concrete Institute (ACI code conservatively predicted the measured values, and, thus, the existing equation in the ACI code is feasible for confined RC columns that contain HVFA. In addition, an analysis model was calibrated based on the experimental results and is recommended for predicting the stress-strain relationship of confined reinforced concrete columns that contain HVFA.

Gestational stress induces persistent depressive-like behavior and structural modifications within the postpartum nucleus accumbens

Science.gov (United States)

Haim, Achikam; Sherer, Morgan; Leuner, Benedetta

2015-01-01

Postpartum depression (PPD) is a common complication following childbirth experienced by one in every five new mothers. Pregnancy stress enhances vulnerability to PPD and has also been shown to increase depressive-like behavior in postpartum rats. Thus, gestational stress may be an important translational risk factor that can be used to investigate the neurobiological mechanisms underlying PPD. Here we examined the effects of gestational stress on depressive-like behavior during the early/mid and late postpartum periods and evaluated whether this was accompanied by altered structural plasticity in the nucleus accumbens (NAc), a brain region that has been linked to PPD. We show that early/mid (PD8) postpartum female rats exhibited more depressive-like behavior in the forced swim test as compared to late postpartum females (PD22). However, two weeks of restraint stress during pregnancy increased depressive-like behavior regardless of postpartum timepoint. In addition, dendritic length, branching, and spine density on medium spiny neurons in the NAc shell were diminished in postpartum rats that experienced gestational stress although stress-induced reductions in spine density were evident only in early/mid postpartum females. In the NAc core, structural plasticity was not affected by gestational stress but late postpartum females exhibited lower spine density and reduced dendritic length. Overall, these data not only demonstrate structural changes in the NAc across the postpartum period, they also show that postpartum depressive-like behavior following exposure to gestational stress is associated with compromised structural plasticity in the NAc and thus may provide insight into the neural changes that could contribute to PPD. PMID:25359225

An extension of the theory of planned behavior to predict pedestrians' violating crossing behavior using structural equation modeling.

Science.gov (United States)

Zhou, Hongmei; Romero, Stephanie Ballon; Qin, Xiao

2016-10-01

This paper aimed to examine pedestrians' self-reported violating crossing behavior intentions by applying the theory of planned behavior (TPB). We studied the behavior intentions regarding instrumental attitude, subjective norm, perceived behavioral control, the three basic components of TPB, and extended the theory by adding new factors including descriptive norm, perceived risk and conformity tendency to evaluate their respective impacts on pedestrians' behavior intentions. A questionnaire presented with a scenario that pedestrians crossed the road violating the pedestrian lights at an intersection was designed, and the survey was conducted in Dalian, China. Based on the 260 complete and valid responses, reliability and validity of the data for each question was evaluated. The data were then analyzed by using the structural equation modeling (SEM). The results showed that people had a negative attitude toward the behavior of violating road-crossing rules; they perceived social influences from their family and friends; and they believed that this kind of risky behavior would potentially harm them in a traffic accident. The results also showed that instrumental attitude and subjective norm were significant in the basic TPB model. After adding descriptive norm, subjective norm was no more significant. Other models showed that conformity tendency was a strong predictor, indicating that the presence of other pedestrians would influence behavioral intention. The findings could help to design more effective interventions and safety campaigns, such as changing people's attitude toward this violation behavior, correcting the social norms, increasing their safety awareness, etc. in order to reduce pedestrians' road crossing violations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Paternal influences on adolescent sexual risk behaviors: a structured literature review.

Science.gov (United States)

Guilamo-Ramos, Vincent; Bouris, Alida; Lee, Jane; McCarthy, Katharine; Michael, Shannon L; Pitt-Barnes, Seraphine; Dittus, Patricia

2012-11-01

To date, most parent-based research has neglected the role of fathers in shaping adolescent sexual behavior and has focused on mothers. The objective of this study was to conduct a structured review to assess the role of paternal influence on adolescent sexual behavior and to assess the methodological quality of the paternal influence literature related to adolescent sexual behavior. We searched electronic databases: PubMed, PsychINFO, Social Services Abstracts, Family Studies Abstracts, Sociological Abstracts, and the Cumulative Index to Nursing and Allied Health Literature. Studies published between 1980 and 2011 that targeted adolescents 11 to 18 years and focused on paternal parenting processes were included. Methodological quality was assessed by using an 11-item scoring system. Thirteen articles were identified and reviewed. Findings suggest paternal factors are independently associated with adolescent sexual behavior relative to maternal factors. The most commonly studied paternal influence was emotional qualities of the father-adolescent relationship. Paternal communication about sex was most consistently associated with adolescent sexual behavior, whereas paternal attitudes about sex was least associated. Methodological limitations include a tendency to rely on cross-sectional design, nonprobability sampling methods, and focus on sexual debut versus broader sexual behavior. Existing research preliminarily suggests fathers influence the sexual behavior of their adolescent children; however, more rigorous research examining diverse facets of paternal influence on adolescent sexual behavior is needed. We provide recommendations for primary care providers and public health practitioners to better incorporate fathers into interventions designed to reduce adolescent sexual risk behavior.

Paternal Influences on Adolescent Sexual Risk Behaviors: A Structured Literature Review

Science.gov (United States)

Bouris, Alida; Lee, Jane; McCarthy, Katharine; Michael, Shannon L.; Pitt-Barnes, Seraphine; Dittus, Patricia

2012-01-01

BACKGROUND AND OBJECTIVE: To date, most parent-based research has neglected the role of fathers in shaping adolescent sexual behavior and has focused on mothers. The objective of this study was to conduct a structured review to assess the role of paternal influence on adolescent sexual behavior and to assess the methodological quality of the paternal influence literature related to adolescent sexual behavior. METHODS: We searched electronic databases: PubMed, PsychINFO, Social Services Abstracts, Family Studies Abstracts, Sociological Abstracts, and the Cumulative Index to Nursing and Allied Health Literature. Studies published between 1980 and 2011 that targeted adolescents 11 to 18 years and focused on paternal parenting processes were included. Methodological quality was assessed by using an 11-item scoring system. RESULTS: Thirteen articles were identified and reviewed. Findings suggest paternal factors are independently associated with adolescent sexual behavior relative to maternal factors. The most commonly studied paternal influence was emotional qualities of the father-adolescent relationship. Paternal communication about sex was most consistently associated with adolescent sexual behavior, whereas paternal attitudes about sex was least associated. Methodological limitations include a tendency to rely on cross-sectional design, nonprobability sampling methods, and focus on sexual debut versus broader sexual behavior. CONCLUSIONS: Existing research preliminarily suggests fathers influence the sexual behavior of their adolescent children; however, more rigorous research examining diverse facets of paternal influence on adolescent sexual behavior is needed. We provide recommendations for primary care providers and public health practitioners to better incorporate fathers into interventions designed to reduce adolescent sexual risk behavior. PMID:23071205

Fluence behavior of polyethylene films irradiated with high energy electrons

International Nuclear Information System (INIS)

Pino, Eddy Segura; Silva, Leonardo G. Andrade e

1999-01-01

Polymers are viscoelastic materials at all temperatures, so that mechanical loads induce time dependable deformations. The recovery of these deformations, on load release, take some time and it is not always recovered completely. The main objective of this work was to analyse the creep behavior of electron irradiated polyethylene films. From the experimental results, it was sated that polyethylene creeps less with an increase on irradiation dose and also that creep recovery in this material increases with doses but it is not complete. This behavior can be attributed to the crosslinking effect witch stabilize elements of the molecular structure of the polyethylene, thus reducing their mobility and so inhibiting the creep mechanism. The partial creep recovery could be also attributed to the reticulation effect and to the polyethylene plastic behavior. Additional information on the creep behavior was obtained by fitting the experimental data with exponential functions and evaluating the mathematical parameters with a modified Kelvin-Voigt mechanical model. (author)

High-pressure behavior of CaMo O4

Science.gov (United States)

Panchal, V.; Garg, N.; Poswal, H. K.; Errandonea, D.; Rodríguez-Hernández, P.; Muñoz, A.; Cavalli, E.

2017-09-01

We report a high-pressure study of tetragonal scheelite-type CaMo O4 up to 29 GPa. In order to characterize its high-pressure behavior, we have combined Raman and optical-absorption measurements with density functional theory calculations. We have found evidence of a pressure-induced phase transition near 15 GPa. Experiments and calculations agree in assigning the high-pressure phase to a monoclinic fergusonite-type structure. The reported results are consistent with previous powder x-ray-diffraction experiments, but are in contradiction with the conclusions obtained from earlier Raman measurements, which support the existence of more than one phase transition in the pressure range covered by our studies. The observed scheelite-fergusonite transition induces significant changes in the electronic band gap and phonon spectrum of CaMo O4 . We have determined the pressure evolution of the band gap for the low- and high-pressure phases as well as the frequencies and pressure dependencies of the Raman-active and infrared-active modes. In addition, based on calculations of the phonon dispersion of the scheelite phase, carried out at a pressure higher than the transition pressure, we propose a possible mechanism for the reported phase transition. Furthermore, from the calculations we determined the pressure dependence of the unit-cell parameters and atomic positions of the different phases and their room-temperature equations of state. These results are compared with previous experiments showing a very good agreement. Finally, information on bond compressibility is reported and correlated with the macroscopic compressibility of CaMo O4 . The reported results are of interest for the many technological applications of this oxide.

Extended fuel swelling models and ultra high burn-up fuel behavior of U–Pu–Zr metallic fuel using FEAST-METAL

Energy Technology Data Exchange (ETDEWEB)

Karahan, Aydın, E-mail: karahan@alum.mit.edu [Center for Advanced Nuclear Energy Systems, Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 24-215, Cambridge, MA 02139 (United States); Andrews, Nathan C., E-mail: nandrews@mit.edu [Center for Advanced Nuclear Energy Systems, Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 24-215, Cambridge, MA 02139 (United States)

2013-05-15

Highlights: ► Improved fuel swelling models in phase structure dependent form. ► A probabilistic verification exercise for the open porosity formation threshold. ► Satisfactory validation effort for available EBR-II database. ► Ultra high burn-up behavior of U–6Zr fuel with 60% smear density fuel. -- Abstract: Computational models in FEAST-METAL U–Pu–Zr metallic fuel behavior code have been upgraded to improve fission gas, solid fission product swelling, and pore sintering behavior in a microstructure dependent form. First, fission gas bubble growth is modeled by selecting small and large bubble groups according to a fixed number of gas atoms per bubble group. Small bubbles nucleated at phase boundaries grow via gas migration and turn into large bubbles. Furthermore, bubble morphology for each phase structure is captured by selecting the number of atoms per bubble and the shape of the bubbles in a phase dependent form. The gas diffusion coefficients for the single gamma phase and effective dual (α + δ) and (β + γ) phase structures are modeled separately, using the activation energy of the corresponding phase structure. In this study, it is found that pressure sintering of the interconnected porosity in dual phases should be less effective than the reference model in order to match clad strain and fission gas release behavior. In addition to these improvements, a probabilistic approach is taken to verify the fission gas-swelling threshold at which interconnected porosity begins. This fracture problem is treated as a function of critical crack length formed via bubble coalescence. It was found that a 10% gas-swelling threshold is appropriate for a wide range of gas bubble sizes. The new version of FEAST-METAL predicts the burn-up, smear density, and axial variation of the clad hoop strain and fission gas release behavior satisfactorily for selected test pins under EBR-II conditions. The code is used to predict ultra-high burn-up U–Pu–6Zr vented

Extended fuel swelling models and ultra high burn-up fuel behavior of U–Pu–Zr metallic fuel using FEAST-METAL

International Nuclear Information System (INIS)

Karahan, Aydın; Andrews, Nathan C.

2013-01-01

Highlights: ► Improved fuel swelling models in phase structure dependent form. ► A probabilistic verification exercise for the open porosity formation threshold. ► Satisfactory validation effort for available EBR-II database. ► Ultra high burn-up behavior of U–6Zr fuel with 60% smear density fuel. -- Abstract: Computational models in FEAST-METAL U–Pu–Zr metallic fuel behavior code have been upgraded to improve fission gas, solid fission product swelling, and pore sintering behavior in a microstructure dependent form. First, fission gas bubble growth is modeled by selecting small and large bubble groups according to a fixed number of gas atoms per bubble group. Small bubbles nucleated at phase boundaries grow via gas migration and turn into large bubbles. Furthermore, bubble morphology for each phase structure is captured by selecting the number of atoms per bubble and the shape of the bubbles in a phase dependent form. The gas diffusion coefficients for the single gamma phase and effective dual (α + δ) and (β + γ) phase structures are modeled separately, using the activation energy of the corresponding phase structure. In this study, it is found that pressure sintering of the interconnected porosity in dual phases should be less effective than the reference model in order to match clad strain and fission gas release behavior. In addition to these improvements, a probabilistic approach is taken to verify the fission gas-swelling threshold at which interconnected porosity begins. This fracture problem is treated as a function of critical crack length formed via bubble coalescence. It was found that a 10% gas-swelling threshold is appropriate for a wide range of gas bubble sizes. The new version of FEAST-METAL predicts the burn-up, smear density, and axial variation of the clad hoop strain and fission gas release behavior satisfactorily for selected test pins under EBR-II conditions. The code is used to predict ultra-high burn-up U–Pu–6Zr vented

ON SHEAR BEHAVIOR OF STRUCTURAL ELEMENTS MADE OF STEEL FIBER REINFORCED CONCRETE

OpenAIRE

Cuenca Asensio, Estefanía

2013-01-01

Cuenca Asensio, E. (2012). ON SHEAR BEHAVIOR OF STRUCTURAL ELEMENTS MADE OF STEEL FIBER REINFORCED CONCRETE [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/18326. Palancia

Availability of high school extracurricular sports programs and high-risk behaviors.

Science.gov (United States)

Cohen, Deborah A; Taylor, Stephanie L; Zonta, Michela; Vestal, Katherine D; Schuster, Mark A

2007-02-01

The Surgeon General has called for an expansion of school-based extracurricular sports programs to address the obesity epidemic. However, little is known about the availability of and participation in high school extracurricular sports and how participation in these sports is related to high-risk behaviors. We surveyed Los Angeles County public high schools in 2002 to determine the number of extracurricular sports programs offered and the percentage of students participating in those programs. We used community data on rates of arrests, births, and sexually transmitted diseases (STDs) among youth to examine associations between risk behaviors and participation in sports programs. The average school offered 14 sports programs, and the average participation rate was 39% for boys and 30% for girls. Smaller schools and schools with higher percentages of disadvantaged students offered fewer programs. The average school offering 13 or fewer programs had 14% of its students participating, while the average school offering 16 or more programs had 31% of its students participating in sports. Controlling for area-level demographics, juvenile arrest rates and teen birth rates, but not STD rates, were lower in areas where schools offered more extracurricular sports. Opportunities for participation in high school extracurricular sports are limited. Future studies should test whether increased opportunities will increase physical activity and impact the increasing overweight problem in youths.

Cigarette use by adolescents: attitude-behavior relationships.

Science.gov (United States)

O'Callaghan, F V; Callan, V J; Baglioni, A

1999-02-01

Structural equation models were used to test the effectiveness of various theories in predicting cigarette smoking among adolescents. Maximum-likelihood estimation, as implemented in LISREL for Windows 8.12, was used to compare the theory of reasoned action (TRA), the theory of planned behavior, and a modified version of the theory of reasoned action incorporating past behavior. Respondents consisted of 225 high school students who were questioned in 1994 about their attitudes, subjective norms, perceived behavioral control, past behavior, intentions, and actual behavior relating to the use of cigarettes. Results indicated that the modification of the TRA incorporating past behavior provided a marginally better fit than the other models. For this group of high school students, attitudes toward smoking, past behavior in relation to smoking, and perceptions of what significant others think they should do were significant predictors of their intentions to smoke. Intentions, together with past behavior, predicted their actual behavior. The models used in the present research show that this behavior can be explained with reference to a small number of key variables which are useful for furthering our understanding of the structure of adolescent smoking.

High temperature strength and aging behavior of 12%Cr-15%Mn austenitic steels

International Nuclear Information System (INIS)

Miyahara, Kazuya; Bae, Dong-Su; Sakai, Hidenori; Hosoi, Yuzo

1993-01-01

High Mn-Cr austenitic steels are still considered to be an important high temperature structural material from the point of view of reduced radio-activation. The objective of the present study is to make a fundamental research of mechanical properties and microstructure of 12%Cr-15%Mn austenitic steels. Especially the effects of alloying elements of V and Ti on the mechanical properties and microstructure evolution of high Mn-Cr steels were studied. Precipitation behaviors of carbides, nitrides and σ phase are investigated and their remarkable effects on the high temperature strength are found. The addition of V was very effective for strengthening the materials with the precipitation of fine VN. Ti was also found to be beneficial for the improvement of high temperature strength properties. The results of high temperature strengths of the 12Cr-15Mn austenitic steels were compared with those of the other candidate and/or reference materials, for example, JFMS (modified 9Cr-2Mo ferritic stainless steel) and JPCAs (modified 316 austenitic stainless steels). (author)

Deformation behavior of large, high-pressure vessel flanges

International Nuclear Information System (INIS)

Spaas, H.A.C.M.; Latzko, D.G.H.

1975-01-01

The analysis of the deformation behavior of large high-pressure vessel flanges poses a much more difficult problem than for low-pressure flanges due to their particular geometry. For a particularly narrow flange geometry (typical of PWR flanges) a finite-element analysis (MARC-IBM-program, eight-node, isoparametric ring elements) was used to predict the behavior of the flange rings. The nonlinear elastic problem resulting from the local closing and/or opening of the partial gap between the gasket faces was solved by an incremental technique using gap elements. The resulting deformation behavior of the flange system has been compared to that obtained from an analysis using the refined rigid ring concept for both bolt-tightening and hydro-testing conditions. The elasto-plastic analysis was solved by the same finite element program system as mentioned above. The incremental steps describing the nonlinear material behavior are allowed to be larger than those for the gap-closure mechanism. Besides a comparison with the former elastic analyses an interpretation will be given of the local plasticity effects, which result in a shift in location of the gasket reaction. Experimental data on local gasket face deformation was obtained by a specially developed laser beam apparatus, with the leak detection channel of the flange serving as a beam hole. Additionally strain gauges were used on flanges and bolts, in combination with special sensing pins for the determination of relative flange rotations. Results obtained so far indicate that for high-pressure flanges of the narrow design investigated here the deformation behavior is best described by an elasto-plastic finite element analysis

Structural and Behavioral Correlates of HIV Infection among Pregnant Women in a Country with a Highly Generalized HIV Epidemic: A Cross-Sectional Study with a Probability Sample of Antenatal Care Facilities in Swaziland.

Directory of Open Access Journals (Sweden)

Bhekumusa Wellington Lukhele

Full Text Available HIV disproportionately affects women in Sub-Saharan Africa. Swaziland bears the highest HIV prevalence of 41% among pregnant women in this region. This heightened HIV-epidemic reflects the importance of context-specific interventions. Apart from routine HIV surveillance, studies that examine structural and behavioral factors associated with HIV infection among women may facilitate the revitalization of existing programs and provide insights to inform context-specific HIV prevention interventions.This cross-sectional study employed a two-stage random cluster sampling in ten antenatal health care facilities in the Hhohho region of Swaziland in August and September 2015. Participants were eligible for the study if they were 18 years or older and had tested for HIV. Self-administered tablet-based questionnaires were used to assess HIV risk factors. Of all eligible pregnant women, 827 (92.4% participated, out of which 297 (35.9% were self-reportedly HIV positive. Among structural factors, family function was not significantly associated with self-reported HIV positive status, while lower than high school educational attainment (AOR, 1.65; CI, 1.14-3.38; P = 0.008, and income below minimum wage (AOR, 1.81; CI, 1.09-3.01; P = 0.021 were significantly associated with self-reported HIV positive status. Behavioral factors significantly associated with reporting a positive HIV status included; ≥2 lifetime sexual partners (AOR, 3.16; CI, 2.00-5.00; P<0.001, and ever cohabited (AOR, 2.39; CI, 1.66-3.43; P = 0.00. The most cited reason for having multiple sexual partners was financial gain. HIV/AIDS-related knowledge level was high but not associated to self-reported HIV status (P = 0.319.Structural and behavioral factors showed significant association with self-reported HIV infection among pregnant women in Swaziland while HIV/AIDS-related knowledge and family function did not. This suggests that HIV interventions should be reinforced taking into

The effectiveness of training acceptance / commitment and training emotion regulation on high-risk behaviors of students with dyscalculia.

Science.gov (United States)

Narimani, Mohammad; Abbasi, Moslem; Abolghasemi, Abbas; Ahadi, Batoul

2013-09-01

Now a days the utilization of Acceptance / Commitment and Emotion Regulation Strategy as a comprehensive treatment plan has been discussed in both the prevention and the control of destructive and risky behaviors. Treatment based on Acceptance/Commitment and Emotion Regulation was effective in both the improvement and the control of high-risk behaviors of students with dyscalculia. The purpose of this study was to investigate the effectiveness of Acceptance and Commitment, and Emotional Regulation training in high-risk behaviors of students with dyscalculia. This research was experimental, with pre-test, post-test and a control group. The statistical universe of this study included all sixth-grade male students in Ardabil city in the academic year of 2012-2013 (A.H.). The subjects of this study involved 800 sixth-grade elementary students in Ardabil province, selected using a multi-stage cluster sampling. From among them, 60 students with dyscalculia were selected using random sampling method after the initial diagnosis by structured clinical interview and the Keymath Mathematic test. Twenty pupil were selected for either the experimental or the control group. To collect data, the questionnaires of "Keymath Mathematic test" and High-risk Behavior" were used. The results of Multivariate Analysis of Variance (MANOVA) showed that "Acceptance / Commitment and Emotion Regulation" treatment trainings were effective in reducing high-risk behaviors, in a manner that they led to a reduction in negative emotions, self-destructive and impulsive behaviors of students with math disorder (dyscalculia). It can be concluded that teaching these skills to the students has been influential in enhancing awareness level and change or positive attitude creation in the subjects. Therefore, it is essential to design and implement interventions based on "prevention caused by the peer group, in collaboration with the parents either at the school or at home among the family members".

Structural Equation Modelling in Behavioral Intention to Use Safety Helmet Reminder System

Directory of Open Access Journals (Sweden)

Rosli Naida

2016-01-01

Full Text Available Motorcycle is one of private transportation which has been widely used in many countries including Malaysia. However, motorcycles are the most dangerous form of motorized transport. Royal Malaysian Police (PDRM statistics recorded that motorcycle is the highest vehicle (45.9% involved in traffic accident compared to other vehicles. The potential cause of the death to the motorcyclist was due to the head injury. One of strategy to mitigate this problem is through proper usage of safety helmet. Therefore, this paper was introduce a new approach on motorcyclist safety by using the Technology Acceptance Model (TAM with additional determinants that contribute to behavioral intention and to increase the proper usage of safety helmets among Malaysian motorcyclists. The Structural Equation Modelling (SEM was used to test the structural TAM proposed. The evaluation for structural model showed the goodness of fit indices are excellent fit. This study found that perceived ease of use, perceived usefulness and social norm are significant towards behavioral intention to use Safety Helmet Reminder System (SHR.

Electronic behavior of highly correlated metals

International Nuclear Information System (INIS)

Reich, A.

1988-10-01

This thesis addresses the question of the strongly interacting many-body problem: that is, systems where the interparticle correlations are so strong as to defy perturbative approaches. These subtle correlations occur in narrow band materials, such as the lanthanides and actinides, wherein the f-electrons are so localized that a variety of new phenomena, including intermediate-valence and heavy-fermionic behavior, may occur. As well, one has the alloying problem, where local interactions are paramount in determining the overall behavior. The technique employed in dealing with these systems is the Small Cluster method, wherein the full many-body Hamiltonian for a small grouping of atoms, coupled with periodic boundary conditions, is solved exactly. This is tantamount to solving a bulk crystal at the high points of symmetry in the Brillouin Zone. The mathematical overhead is further reduced by employing the full space group and spin symmetries. By its very nature, the Small Cluster method is well able to handle short-range interactions, as well as the combinatorial complexity of the many-body problem, on an equal footing. The nature of long-range order and phase transition behavior cannot be incorporated, but sometimes clues as to their origin can be discerned. The calculations presented include: a two-band Anderson model for an intermediate-valence system, wherein photoemission and fluctuation behavior is examined; a single-band Hubbard model for a ternary alloy system, such as copper-silver-gold; and a Hubbard model for a heavy- fermion system, wherein Fermi surface, transport, magnetic and superconducting properties are discussed. 148 refs., 31 figs., 24 tabs

Acceptability, language, and structure of text message-based behavioral interventions for high-risk adolescent females: a qualitative study.

Science.gov (United States)

Ranney, Megan L; Choo, Esther K; Cunningham, Rebecca M; Spirito, Anthony; Thorsen, Margaret; Mello, Michael J; Morrow, Kathleen

2014-07-01

To elucidate key elements surrounding acceptability/feasibility, language, and structure of a text message-based preventive intervention for high-risk adolescent females. We recruited high-risk 13- to 17-year-old females screening positive for past-year peer violence and depressive symptoms, during emergency department visits for any chief complaint. Participants completed semistructured interviews exploring preferences around text message preventive interventions. Interviews were conducted by trained interviewers, audio-recorded, and transcribed verbatim. A coding structure was iteratively developed using thematic and content analysis. Each transcript was double coded. NVivo 10 was used to facilitate analysis. Saturation was reached after 20 interviews (mean age 15.4; 55% white; 40% Hispanic; 85% with cell phone access). (1) Acceptability/feasibility themes: A text-message intervention was felt to support and enhance existing coping strategies. Participants had a few concerns about privacy and cost. Peer endorsement may increase uptake. (2) Language themes: Messages should be simple and positive. Tone should be conversational but not slang filled. (3) Structural themes: Messages may be automated but must be individually tailored on a daily basis. Both predetermined (automatic) and as-needed messages are requested. Dose and timing of content should be varied according to participants' needs. Multimedia may be helpful but is not necessary. High-risk adolescent females seeking emergency department care are enthusiastic about a text message-based preventive intervention. Incorporating thematic results on language and structure can inform development of future text messaging interventions for adolescent girls. Concerns about cost and privacy may be able to be addressed through the process of recruitment and introduction to the intervention. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Thermo-structural analysis and electrical conductivity behavior of epoxy/metals composites

Science.gov (United States)

Boumedienne, N.; Faska, Y.; Maaroufi, A.; Pinto, G.; Vicente, L.; Benavente, R.

2017-05-01

This paper reports on the elaboration and characterization of epoxy resin filled with metallic particles powder (aluminum, tin and zinc) composites. The scanning electron microscopy (SEM) pictures, density measurements and x-ray diffraction analysis (DRX) showed a homogeneous phase of obtained composites. The differential scanning calorimetry revealed a good adherence at matrix-filler interfaces, confirming the SEM observations. The measured glass transition temperatures depend on composites fillers' nature. Afterwards, the electrical conductivity of composites versus their fillers' contents has been investigated. The obtained results depict a nonlinear behavior, indicating an insulator to conductor phase transition at a conduction threshold; with high contrast of ten decades. Hence, the elaborated materials give a possibility to obtain dielectric or electrically conducting phases, which can to be interesting in the choice of desired applications. Finally, the obtained results have been successfully simulated on the basis of different percolation models approach combined with structural characterization inferences.

Localized bending fatigue behavior of high-strength steel monostrands

DEFF Research Database (Denmark)

Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.

2012-01-01

In this paper, the localized bending fatigue behavior of pretensioned high strength steel monostrands is investigated. Furthermore, a new methodology using an optical photogrammetry system, which can quantify surface deformations on the strand is presented. The system allows measurement of the st......In this paper, the localized bending fatigue behavior of pretensioned high strength steel monostrands is investigated. Furthermore, a new methodology using an optical photogrammetry system, which can quantify surface deformations on the strand is presented. The system allows measurement...... displacement (opening/closing and sliding) of the helically wound wires. Moreover, the results are a step towards understanding the bending fatigue damage mechanisms of monostrand cables....

Effects of Comprehensive, Multiple High-Risk Behaviors Prevention Program on High School Students

Science.gov (United States)

Collier, Crystal

2013-01-01

The purpose of this mixed methods study was to examine the effect of a multiple high-risk behaviors prevention program applied comprehensively throughout an entire school-system involving universal, selective, and indicated levels of students at a local private high school during a 4-year period. The prevention program was created based upon the…

Core Competencies and the Prevention of High-Risk Sexual Behavior

Science.gov (United States)

Charles, Vignetta Eugenia; Blum, Robert Wm.

2008-01-01

Adolescent sexual risk-taking behavior has numerous individual, family, community, and societal consequences. In an effort to contribute to the research and propose new directions, this chapter applies the core competencies framework to the prevention of high-risk sexual behavior. It describes the magnitude of the problem, summarizes explanatory…

Ontology-Based High-Level Context Inference for Human Behavior Identification

Science.gov (United States)

Villalonga, Claudia; Razzaq, Muhammad Asif; Khan, Wajahat Ali; Pomares, Hector; Rojas, Ignacio; Lee, Sungyoung; Banos, Oresti

2016-01-01

Recent years have witnessed a huge progress in the automatic identification of individual primitives of human behavior, such as activities or locations. However, the complex nature of human behavior demands more abstract contextual information for its analysis. This work presents an ontology-based method that combines low-level primitives of behavior, namely activity, locations and emotions, unprecedented to date, to intelligently derive more meaningful high-level context information. The paper contributes with a new open ontology describing both low-level and high-level context information, as well as their relationships. Furthermore, a framework building on the developed ontology and reasoning models is presented and evaluated. The proposed method proves to be robust while identifying high-level contexts even in the event of erroneously-detected low-level contexts. Despite reasonable inference times being obtained for a relevant set of users and instances, additional work is required to scale to long-term scenarios with a large number of users. PMID:27690050

Ontology-Based High-Level Context Inference for Human Behavior Identification

Directory of Open Access Journals (Sweden)

Claudia Villalonga

2016-09-01

Full Text Available Recent years have witnessed a huge progress in the automatic identification of individual primitives of human behavior, such as activities or locations. However, the complex nature of human behavior demands more abstract contextual information for its analysis. This work presents an ontology-based method that combines low-level primitives of behavior, namely activity, locations and emotions, unprecedented to date, to intelligently derive more meaningful high-level context information. The paper contributes with a new open ontology describing both low-level and high-level context information, as well as their relationships. Furthermore, a framework building on the developed ontology and reasoning models is presented and evaluated. The proposed method proves to be robust while identifying high-level contexts even in the event of erroneously-detected low-level contexts. Despite reasonable inference times being obtained for a relevant set of users and instances, additional work is required to scale to long-term scenarios with a large number of users.

Structural phase transitions in Zn(CN)2 under high pressures

International Nuclear Information System (INIS)

Poswal, H.K.; Tyagi, A.K.; Lausi, Andrea; Deb, S.K.; Sharma, Surinder M.

2009-01-01

High pressure behavior of zinc cyanide (Zn(CN) 2 ) has been investigated with the help of synchrotron-based X-ray diffraction measurements. Our studies reveal that under pressure this compound undergoes phase transformations and the structures of the new phases depend on whether the pressure is hydrostatic or not. Under hydrostatic conditions, Zn(CN) 2 transforms from cubic to orthorhombic to cubic-II to amorphous phases. In contrast, the non-hydrostatic pressure conditions drive the ambient cubic phase to a partially disordered crystalline phase, which eventually evolves to a substantially disordered phase. The final disordered phase in the latter case is distinct from the amorphous phase observed under the hydrostatic pressures. - Graphical abstract: High pressure X-ray diffraction investigations on Zn(CN) 2 show three phase transformations i.e., cubic→orthorhombic→cubic-II→amorphous. However, the results strongly depend upon the nature of stress

Corrosion behavior of Ni-based structural materials for electrolytic reduction in lithium molten salt

Energy Technology Data Exchange (ETDEWEB)

Cho, Soo Haeng, E-mail: nshcho1@kaeri.re.kr [Korea Atomic Energy Research Institute, 1045 Daedeokdaero Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Park, Sung Bin [Korea Atomic Energy Research Institute, 1045 Daedeokdaero Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Jong Hyeon, E-mail: jonglee@cnu.ac.kr [Graduate School of Green Energy Technology, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Hur, Jin Mok; Lee, Han Soo [Korea Atomic Energy Research Institute, 1045 Daedeokdaero Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

2011-05-01

In this study, the corrosion behavior of new Ni-based structural materials was studied for electrolytic reduction after exposure to LiCl-Li{sub 2}O molten salt at 650 deg. C for 24-216 h under an oxidizing atmosphere. The new alloys with Ni, Cr, Al, Si, and Nb as the major components were melted at 1700 deg. C under an inert atmosphere. The melt was poured into a preheated metallic mold to prepare an as-cast alloy. The corrosion products and fine structures of the corroded specimens were characterized by scanning electron microscope (SEM), Energy Dispersive X-ray Spectroscope (EDS), and X-ray diffraction (XRD). The corrosion products of as cast and heat treated low Si/high Ti alloys were Cr{sub 2}O{sub 3}, NiCr{sub 2}O{sub 4}, Ni, NiO, and (Al,Nb,Ti)O{sub 2}; those of as cast and heat treated high Si/low Ti alloys were Cr{sub 2}O{sub 3}, NiCr{sub 2}O{sub 4}, Ni, and NiO. The corrosion layers of as cast and heat treated low Si/high Ti alloys were continuous and dense. However, those of as cast and heat treated high Si/low Ti alloys were discontinuous and cracked. Heat treated low Si/high Ti alloy showed the highest corrosion resistance among the examined alloys. The superior corrosion resistance of the heat treated low Si/high Ti alloy was attributed to the addition of an appropriate amount of Si, and the metallurgical evaluations were performed systematically.

High-risk sexual behavior among drug-using men.

Science.gov (United States)

Seidman, S N; Sterk-Elifson, C; Aral, S O

1994-01-01

Drug-using men are at high risk for acquisition and transmission of STD, presumably due to the risky behaviors practiced in environments of drug use. To study behaviors associated with STD transmission among drug-using men. Drug outreach workers distributed vouchers to self-identified drug-using men in urban Atlanta. Vouchers could be redeemed for cash at a storefront clinic where subjects provided urine for a urethritis screening test (leukocyte esterase test) and a drug screen, and were interviewed. Of 382 voucher recipients, 252 (66%) came to the clinic. Subjects were predominantly black (92%), homeless (70%), and aged 20 to 40 (88%). All used illicit drugs; none were currently receiving drug abuse treatment. Urine drug screen confirmed recent cocaine use in 63%, and recent opiate use in 4%. Three-fourths reported a history of STD, mostly gonorrhea. In the preceding 3 months, 14% had not had sex, 80% had sex exclusively with women, 4% had sex with both men and women, and 2% had sex exclusively with men. Of the heterosexually active men, 29% had 5 or more recent partners. Compared to other heterosexually active men, these men were more likely to always use alcohol or crack before having sex (prevalence ratio [PR] = 2.0, 95% CI = 1.3-2.5) and to drink alcohol every day (PR = 2.0, 95% CI = 1.2-3.3). Daily crack use was associated with choosing partners at elevated STD risk; daily alcohol use with having more partners. Positive drug screen for cocaine was associated with self-reported crack use. Urethritis, detected in 16%, was not correlated with behavior. A substantial number of drug-using men practice high-risk sexual behavior and should be targeted for intervention. Monetary and other incentives should be considered for recruitment. Further study is needed to clarify the relationship between sexual behavior, cocaine use, and STD.

Experimental Study on the Structural Behavior of HSC Slab under out of plane load

International Nuclear Information System (INIS)

Ham, K. W.; Lee, K. J.; Park, D. S.

2009-01-01

HSC(Half Steel plate Concrete) Slab is a kind of SC(Steel plate Concrete) structure, so it has a similar advantage of SC structures (short construction period, lower cost and good quality control compared to RC). To apply HSC to the slab of containment building of NPP, several test with different test condition (shear span ratio, shear bar, loading type) were conducted to verify structural behavior of HSC slab structure under out of plane loading

Structural Behavior of Concrete Beams Reinforced with Basalt Fiber Reinforced Polymer (BFRP) Bars

Science.gov (United States)

Ovitigala, Thilan

The main challenge for civil engineers is to provide sustainable, environmentally friendly and financially feasible structures to the society. Finding new materials such as fiber reinforced polymer (FRP) material that can fulfill the above requirements is a must. FRP material was expensive and it was limited to niche markets such as space shuttles and air industry in the 1960s. Over the time, it became cheaper and spread to other industries such as sporting goods in the 1980-1990, and then towards the infrastructure industry. Design and construction guidelines are available for carbon fiber reinforced polymer (CFRP), aramid fiber reinforced polymer (AFRP) and glass fiber reinforced polymer (GFRP) and they are currently used in structural applications. Since FRP is linear elastic brittle material, design guidelines for the steel reinforcement are not valid for FRP materials. Corrosion of steel reinforcement affects the durability of the concrete structures. FRP reinforcement is identified as an alternative to steel reinforcement in corrosive environments. Although basalt fiber reinforced polymer (BFRP) has many advantages over other FRP materials, but limited studies have been done. These studies didn't include larger BFRP bar diameters that are mostly used in practice. Therefore, larger beam sizes with larger BFRP reinforcement bar diameters are needed to investigate the flexural and shear behavior of BFRP reinforced concrete beams. Also, shear behavior of BFRP reinforced concrete beams was not yet studied. Experimental testing of mechanical properties and bond strength of BFRP bars and flexural and shear behavior of BFRP reinforced concrete beams are needed to include BFRP reinforcement bars in the design codes. This study mainly focuses on the use of BFRP bars as internal reinforcement. The test results of the mechanical properties of BFRP reinforcement bars, the bond strength of BFRP reinforcement bars, and the flexural and shear behavior of concrete beams

Co-relationship between sexual dysfunction and high-risk sexual behavior in patients receiving buprenorphine and naltrexone maintenance therapy for opioid dependence.

Science.gov (United States)

Ramdurg, Santosh; Ambekar, Atul; Lal, Rakesh

2015-01-01

People suffering from substance dependence suffer from various sexual dysfunctions and are at risk for indulging in various high-risk sexual behaviors and thus are vulnerable to acquire various infections such as HIV/AIDS and other sexually transmitted infections. The aim of the study was to evaluate the correlation between sexual dysfunction and high-risk sexual behavior in opioid-dependent men receiving buprenorphine and naltrexone maintenance therapy. Semi-structured questionnaire, brief male sexual functioning inventory and HIV-risk taking behavior scale was administered to a sample of 60 sexually active men, receiving buprenorphine (n = 30) and naltrexone (n = 30) maintenance therapy for opioid dependence. The main outcomes are correlation between severity of sexual dysfunction and HIV-risk taking behavior. The study results showed 83% of the men on buprenorphine and 90% on naltrexone reported at least one of the sexual dysfunction symptoms. There was a negative correlation between sexual dysfunction and HIV-risk taking behavior that suggest severe the dysfunction, higher the risk taking behavior. Significant correlation was present with overall sexual dysfunction and HIV-risk taking behavior (P = 0.028 and in naltrexone receiving group premature ejaculation versus HIV-risk taking behavior however, (P = 0.022, P sexual dysfunctions and HIV-risk taking behavior, which has clinical implication. Future research should explore this further using biochemical analyses.

The structural properties of Zr-based bulk metallic glasses subjected to high pressure torsion at different temperatures

Energy Technology Data Exchange (ETDEWEB)

Boltynjuk, E. V., E-mail: boltynjuk@gmail.com; Ubyivovk, E. V.; Kshumanev, A. M. [Saint Petersburg State University, 28 Universitetskiy pr., Saint Petersburg, 198504 (Russian Federation); Gunderov, D. V.; Lukianov, A. V. [Ufa State Aviation Technical University, K. Marks 12, Ufa, 450000 (Russian Federation); Bednarz, A. [Faculty of Mechanical Engineering and Aeronautics, Department of Aircraft and Aircraft Engines, Rzeszow University of Technology, Al. Powstancow Warszawy 8, 35-959 Rzeszow (Poland); Valiev, R. Z. [Saint Petersburg State University, 28 Universitetskiy pr., Saint Petersburg, 198504 (Russian Federation); Ufa State Aviation Technical University, K. Marks 12, Ufa, 450000 (Russian Federation)

2016-06-17

The structural properties of a Zr{sub 62}Cu{sub 22}Al{sub 10}Fe{sub 5}Dy{sub 1} bulk metallic glasses were investigated. Cylindrical rods of the Zr{sub 62}Cu{sub 22}Al{sub 10}Fe{sub 5}Dy{sub 1} BMG were subjected to high pressure torsion at temperatures of 20°C and 150°C. X-ray diffraction, transmission electron microscopy were used to determine peculiarities of the modified structure. Analysis of fracture surfaces, nanohardness measurements were conducted to investigate the influence of structural changes on mechanical behavior of processed samples.

Embedded high-contrast distributed grating structures

Science.gov (United States)

Zubrzycki, Walter J.; Vawter, Gregory A.; Allerman, Andrew A.

2002-01-01

A new class of fabrication methods for embedded distributed grating structures is claimed, together with optical devices which include such structures. These new methods are the only known approach to making defect-free high-dielectric contrast grating structures, which are smaller and more efficient than are conventional grating structures.

Metal release behavior of surface oxidized stainless steels into flowing high temperature pure water

International Nuclear Information System (INIS)

Fujiwara, Kazuo; Tomari, Haruo; Nakayama, Takenori; Shimogori, Kazutoshi; Ishigure, Kenkichi; Matsuura, Chihiro; Fujita, Norihiko; Ono, Shoichi.

1987-01-01

In order to clarify the effect of oxidation treatment of Type 304 SS on the inhibition of metal release into high temperature pure water, metal release rate of individual alloying element into flowing deionized water containing 50 ppb dissolved oxygen was measured as the function of exposure time on representative specimens oxidized in air and steam. The behavior of metal release was also discussed in relation to the structure of surface films. Among the alloying elements the amount of Fe ion, Cr ion and Fe crud in high temperature pure water tended to saturate with the exposure time and that of Ni ion and Co ion tended to increase monotonously with the exposure time for all specimens tested. And the treatment of steam-oxidation was the most effective to decrease the metal release of alloying elements and the treatment by air-oxidation also decreased the metal release. These tendencies were confirmed to correlate well with the structure of the surface films as it was in the results in the static autoclave test. (author)

Influence of High Temperature Treatment on Mechanical Behavior of a Coarse-grained Marble

Science.gov (United States)

Rong, G.; Peng, J.; Jiang, M.

2017-12-01

High temperature has a significant influence on the physical and mechanical behavior of rocks. With increasing geotechnical engineering structures concerning with high temperature problems such as boreholes for oil or gas production, underground caverns for storage of radioactive waste, and deep wells for injection of carbon dioxides, etc., it is important to study the influence of temperature on the physical and mechanical properties of rocks. This paper experimentally investigates the triaxial compressive properties of a coarse-grained marble after exposure to different high temperatures. The rock specimens were first heated to a predetermined temperature (200, 400, and 600 oC) and then cooled down to room temperature. Triaxial compression tests on these heat-treated specimens subjected to different confining pressures (i.e., 0, 5, 10, 15, 20, 25, 30, 35, and 40 MPa) were then conducted. Triaxial compression tests on rock specimens with no heat treatment were also conducted for comparison. The results show that the high temperature treatment has a significant influence on the microstructure, porosity, P-wave velocity, stress-strain relation, strength and deformation parameters, and failure mode of the tested rock. As the treatment temperature gradually increases, the porosity slightly increases and the P-wave velocity dramatically decreases. Microscopic observation on thin sections reveals that many micro-cracks will be generated inside the rock specimen after high temperature treatment. The rock strength and Young's modulus show a decreasing trend with increase of the treatment temperature. The ductility of the rock is generally enhanced as the treatment temperature increases. In general, the high temperature treatment weakens the performance of the tested rock. Finally, a degradation parameter is defined and a strength degradation model is proposed to characterize the strength behavior of heat-treated rocks. The results in this study provide useful data for

High temperature oxidation behavior of ODS steels

Science.gov (United States)

Kaito, T.; Narita, T.; Ukai, S.; Matsuda, Y.

2004-08-01

Oxide dispersion strengthened (ODS) steels are being developing for application as advanced fast reactor cladding and fusion blanket materials, in order to allow increased operation temperature. Oxidation testing of ODS steel was conducted under a controlled dry air atmosphere to evaluate the high temperature oxidation behavior. This showed that 9Cr-ODS martensitic steels and 12Cr-ODS ferritic steels have superior high temperature oxidation resistance compared to 11 mass% Cr PNC-FMS and 17 mass% Cr ferritic stainless steel. This high temperature resistance is attributed to earlier formation of the protective α-Cr 2O 3 on the outer surface of ODS steels.

Flexural fracture and fatigue behavior of steel-fiber-reinforced concrete structures

International Nuclear Information System (INIS)

Chang, D.I.

1995-01-01

Fracture and fatigue tests were performed in order to investigate the fracture and fatigue behavior of steel-fibre-reinforced concrete (SFRC) structures. 33 SFRC beams were used in the fracture and fatigue tests. The relationship between loading, strain and midspan deflection of the beams was observed under the three-point loading system.From the test results, the effects of the fiber content, fiber aspect ratio and notch-to-depth ratio on the concrete fracture and fatigue behavior were studied, and the fatigue strengths of SFRC beams were calculated. According to the regression technique, some empirical formulae for predicting the fatigue strength of SFRC beams were also suggested. (orig.)

Effects of high mean stress on the high-cycle fatigue behavior of PWA 1480

International Nuclear Information System (INIS)

Majumdar, S.; Antolovich, S.; Milligan, W.

1985-03-01

PWA 1480 is a potential candidate material for use in the high-pressure fuel turbine blade of the Space Shuttle Main Engine. As an engine material it will be subjected to high-cycle fatigue loading superimposed on a high mean stress due to combined centrifugal and thermal loadings. This paper describes results obtained in an ongoing program to determine the effects of a high mean stress on the high-cycle fatigue behavior of this material

Relationship between Drugs Use and Sexual Risk Behaviors among Senior High School Students

Directory of Open Access Journals (Sweden)

Yola Yuniaarti Herijanto

2017-03-01

Full Text Available Background: Drugs use and risky sexual behavior among teenager are some of crucial problems arising in Indonesia. Statistic showed that there is an increasing prevalence in drugs use and risky sexual behavior among teenagers. This study was conducted to analyze the relationship between drugs use and risky sexual behaviors among high school students. Methods: An analytic study involving 432 students in 5 state high schools located in Kerees region Bandung, West Java, Indonesia, was carried out in 2013. The region was chosen due the high prevalence of substance abuse. The inclusion criteria were every high school students in the Karees region. The exclusion criteria were the students who refused to participate in the study, did not come when the sample was taken, and did not fill the questionnaire completely. The instruments used for the study were questionnaires with cross-sectional technique. Furthermore, the questionnaire used for analyzing drugs use was Addiction Severity Index-Lite Version (ASI-lite questionnaire; with additional questionnaire to analyze risky sexual behaviors. Results: Out of 432 students, 23.8% students already engaged to one or more risky sexual behavior. Among all respondents, the prevalence of students who had already done kissing was 22.7%, necking 9.3%, petting 7.2% and sexual intercourse 1.2%. Illegal drugs had been used at least once by 21.8% students. According to Chi-square test, drugs use and risky sexual behavior were related. Conclusions:The prevalence of both drugs use and risky sexual behaviors are high and students who use drugs are more prone to do risky sexual behavior.

Is structured observation a valid technique to measure handwashing behavior? Use of acceleration sensors embedded in soap to assess reactivity to structured observation.

Science.gov (United States)

Ram, Pavani K; Halder, Amal K; Granger, Stewart P; Jones, Therese; Hall, Peter; Hitchcock, David; Wright, Richard; Nygren, Benjamin; Islam, M Sirajul; Molyneaux, John W; Luby, Stephen P

2010-11-01

Structured observation is often used to evaluate handwashing behavior. We assessed reactivity to structured observation in rural Bangladesh by distributing soap containing acceleration sensors and performing structured observation 4 days later. Sensors recorded the number of times soap was moved. In 45 participating households, the median number of sensor soap movements during the 5-hour time block on pre-observation days was 3.7 (range 0.3-10.6). During the structured observation, the median number of sensor soap movements was 5.0 (range 0-18.0), a 35% increase, P = 0.0004. Compared with the same 5-hour time block on pre-observation days, the number of sensor soap movements increased during structured observation by ≥ 20% in 62% of households, and by ≥ 100% in 22% of households. The increase in sensor soap movements during structured observation, compared with pre-observation days, indicates substantial reactivity to the presence of the observer. These findings call into question the validity of structured observation for measurement of handwashing behavior.

Is Structured Observation a Valid Technique to Measure Handwashing Behavior? Use of Acceleration Sensors Embedded in Soap to Assess Reactivity to Structured Observation

Science.gov (United States)

Ram, Pavani K.; Halder, Amal K.; Granger, Stewart P.; Jones, Therese; Hall, Peter; Hitchcock, David; Wright, Richard; Nygren, Benjamin; Islam, M. Sirajul; Molyneaux, John W.; Luby, Stephen P.

2010-01-01

Structured observation is often used to evaluate handwashing behavior. We assessed reactivity to structured observation in rural Bangladesh by distributing soap containing acceleration sensors and performing structured observation 4 days later. Sensors recorded the number of times soap was moved. In 45 participating households, the median number of sensor soap movements during the 5-hour time block on pre-observation days was 3.7 (range 0.3–10.6). During the structured observation, the median number of sensor soap movements was 5.0 (range 0–18.0), a 35% increase, P = 0.0004. Compared with the same 5-hour time block on pre-observation days, the number of sensor soap movements increased during structured observation by ≥ 20% in 62% of households, and by ≥ 100% in 22% of households. The increase in sensor soap movements during structured observation, compared with pre-observation days, indicates substantial reactivity to the presence of the observer. These findings call into question the validity of structured observation for measurement of handwashing behavior. PMID:21036840

High Thermal Conductivity Composite Structures

National Research Council Canada - National Science Library

Bootle, John

1999-01-01

... applications and space based radiators. The advantage of this material compared to competing materials that it can be used to fabricate high strength, high thermal conductivity, relatively thin structures less than 0.050" thick...

The Application of Structural Equation Modeling to Maternal Ratings of Twins' Behavior and Emotional Problems.

Science.gov (United States)

Silberg, Judy L.; And Others

1994-01-01

Applied structural equation modeling to twin data to assess impact of genetic and environmental factors on children's behavioral and emotional functioning. Applied models to maternal ratings of behavior of 515 monozygotic and 749 dizygotic twin pairs. Importance of genetic, shared, and specific environmental factors for explaining variation was…

Plastic damage induced fracture behaviors of dental ceramic layer structures subjected to monotonic load.

Science.gov (United States)

Wang, Raorao; Lu, Chenglin; Arola, Dwayne; Zhang, Dongsheng

2013-08-01

The aim of this study was to compare failure modes and fracture strength of ceramic structures using a combination of experimental and numerical methods. Twelve specimens with flat layer structures were fabricated from two types of ceramic systems (IPS e.max ceram/e.max press-CP and Vita VM9/Lava zirconia-VZ) and subjected to monotonic load to fracture with a tungsten carbide sphere. Digital image correlation (DIC) and fractography technology were used to analyze fracture behaviors of specimens. Numerical simulation was also applied to analyze the stress distribution in these two types of dental ceramics. Quasi-plastic damage occurred beneath the indenter in porcelain in all cases. In general, the fracture strength of VZ specimens was greater than that of CP specimens. The crack initiation loads of VZ and CP were determined as 958 ± 50 N and 724 ± 36 N, respectively. Cracks were induced by plastic damage and were subsequently driven by tensile stress at the elastic/plastic boundary and extended downward toward to the veneer/core interface from the observation of DIC at the specimen surface. Cracks penetrated into e.max press core, which led to a serious bulk fracture in CP crowns, while in VZ specimens, cracks were deflected and extended along the porcelain/zirconia core interface without penetration into the zirconia core. The rupture loads for VZ and CP ceramics were determined as 1150 ± 170 N and 857 ± 66 N, respectively. Quasi-plastic deformation (damage) is responsible for crack initiation within porcelain in both types of crowns. Due to the intrinsic mechanical properties, the fracture behaviors of these two types of ceramics are different. The zirconia core with high strength and high elastic modulus has better resistance to fracture than the e.max core. © 2013 by the American College of Prosthodontists.

Dielectric-Lined High-Gradient Accelerator Structure

Energy Technology Data Exchange (ETDEWEB)

Jay L. Hirshfield

2012-04-24

Rectangular particle accelerator structures with internal planar dielectric elements have been studied, with a view towards devising structures with lower surface fields for a given accelerating field, as compared with structures without dielectrics. Success with this concept is expected to allow operation at higher accelerating gradients than otherwise on account of reduced breakdown probabilities. The project involves studies of RF breakdown on amorphous dielectrics in test cavities that could enable high-gradient structures to be built for a future multi-TeV collider. The aim is to determine what the limits are for RF fields at the surfaces of selected dielectrics, and the resulting acceleration gradient that could be achieved in a working structure. The dielectric of principal interest in this study is artificial CVD diamond, on account of its advertised high breakdown field ({approx}2 GV/m for dc), low loss tangent, and high thermal conductivity. Experimental studies at mm-wavelengths on materials and structures for achieving high acceleration gradient were based on the availability of the 34.3 GHz third-harmonic magnicon amplifier developed by Omega-P, and installed at the Yale University Beam Physics Laboratory. Peak power from the magnicon was measured to be about 20 MW in 0.5 {micro}s pulses, with a gain of 54 dB. Experiments for studying RF high-field effects on CVD diamond samples failed to show any evidence after more than 10{sup 5} RF pulses of RF breakdown up to a tangential surface field strength of 153 MV/m; studies at higher fields were not possible due to a degradation in magnicon performance. A rebuild of the tube is underway at this writing. Computed performance for a dielectric-loaded rectangular accelerator structure (DLA) shows highly competitive properties, as compared with an existing all-metal structure. For example, comparisons were made of a DLA structure having two planar CVD diamond elements with a all-metal CERN structure HDS

Dielectric-Lined High-Gradient Accelerator Structure

International Nuclear Information System (INIS)

Hirshfield, Jay L.

2012-01-01

Rectangular particle accelerator structures with internal planar dielectric elements have been studied, with a view towards devising structures with lower surface fields for a given accelerating field, as compared with structures without dielectrics. Success with this concept is expected to allow operation at higher accelerating gradients than otherwise on account of reduced breakdown probabilities. The project involves studies of RF breakdown on amorphous dielectrics in test cavities that could enable high-gradient structures to be built for a future multi-TeV collider. The aim is to determine what the limits are for RF fields at the surfaces of selected dielectrics, and the resulting acceleration gradient that could be achieved in a working structure. The dielectric of principal interest in this study is artificial CVD diamond, on account of its advertised high breakdown field (∼2 GV/m for dc), low loss tangent, and high thermal conductivity. Experimental studies at mm-wavelengths on materials and structures for achieving high acceleration gradient were based on the availability of the 34.3 GHz third-harmonic magnicon amplifier developed by Omega-P, and installed at the Yale University Beam Physics Laboratory. Peak power from the magnicon was measured to be about 20 MW in 0.5 (micro)s pulses, with a gain of 54 dB. Experiments for studying RF high-field effects on CVD diamond samples failed to show any evidence after more than 10 5 RF pulses of RF breakdown up to a tangential surface field strength of 153 MV/m; studies at higher fields were not possible due to a degradation in magnicon performance. A rebuild of the tube is underway at this writing. Computed performance for a dielectric-loaded rectangular accelerator structure (DLA) shows highly competitive properties, as compared with an existing all-metal structure. For example, comparisons were made of a DLA structure having two planar CVD diamond elements with a all-metal CERN structure HDS operating at 30

Viscoelastic and thermal behavior of structural concrete with reference to containment vessels

International Nuclear Information System (INIS)

Stefanou, G.D.

1981-01-01

A method of numerical viscoelastic stress analysis is described suitable for concrete structures operating at elevated temperatures. The paper describes how approximate numerical methods of elastic analysis of the finite element type can be extended to incorporate the viscoelastic behavior of structural concrete of the quasi-static type. A new eight parameter viscoelastic model is proposed to represent concrete behavior in the loaded and unloaded stage. The deformational expressions for the proposed viscoelastic analogue are also developed. Finally, as a result of courve-fitting procedures, the evaluation of the creep law coefficients are obtained for creep laws appropriate to a test regime. The proposed method is of general application providing that the properties of concrete are assessed reasonably well. The analytical predictions are compared with experimental results obtained on concrete model specimens loaded for 3 1/2 months, at a temperature of 80 0 C. (author)

High-pressure behavior of synthetic mordenite-Na. An in situ single-crystal synchrotron X-ray diffraction study

Energy Technology Data Exchange (ETDEWEB)

Lotti, Paolo; Merlini, Marco [Univ. degli Studi di Milano, (Italy). Dipt. di Scienze della Terra; Gatta, G. Diego [Univ. degli Studi di Milano, (Italy). Dipt. di Scienze della Terra; CNR, Bari (Italy). Int. di Cristallografia; Liermann, Hanns-Peter [DESY, Hamburg (Germany). Photon Sciences

2015-05-01

The high-pressure behavior of a synthetic mordenite-Na (space group: Cmcm or Cmc2{sub 1}) was studied by in situ single-crystal synchrotron X-ray diffraction with a diamond anvil cell up to 9.22(7) GPa. A phase transition, likely displacive in character, occurred between 1.68(7) and 2.70(8) GPa, from a C-centered to a primitive space group: possibly Pbnm, Pbnn or Pbn2{sub 1}. Fitting of the experimental data with III-BM equations of state allowed to describe the elastic behavior of the high-pressure polymorph with a primitive lattice. A very high volume compressibility [K{sub V0} = 25(2) GPa, β{sub V0} = 1/K{sub V0} = 0.040(3) GPa{sup -1}; K{sub V}' = (∂K{sub V}/∂P){sub T} = 2.0(3)], coupled with a remarkable elastic anisotropy (β{sub b}>>β{sub c}>β{sub a}), was found. Interestingly, the low-P and high-P polymorphs show the same anisotropic compressional scheme. A structure collapse was not observed up to 9.22(7) GPa, even though a strong decrease of the number of observed reflections at the highest pressures suggests an impending amorphization. The structure refinements performed at room-P, 0.98(2) and 1.68(7) GPa allowed to describe, at a first approximation, the mechanisms that govern the framework deformation in the low-P regime: the bulk compression is strongly accommodated by the increase of the ellipticity of the large 12-membered ring channels running along [001].

fMRI investigation of response inhibition, emotion, impulsivity, and clinical high-risk behavior in adolescents.

Science.gov (United States)

Brown, Matthew R G; Benoit, James R A; Juhás, Michal; Dametto, Ericson; Tse, Tiffanie T; MacKay, Marnie; Sen, Bhaskar; Carroll, Alan M; Hodlevskyy, Oleksandr; Silverstone, Peter H; Dolcos, Florin; Dursun, Serdar M; Greenshaw, Andrew J

2015-01-01

High-risk behavior in adolescents is associated with injury, mental health problems, and poor outcomes in later life. Improved understanding of the neurobiology of high-risk behavior and impulsivity shows promise for informing clinical treatment and prevention as well as policy to better address high-risk behavior. We recruited 21 adolescents (age 14-17) with a wide range of high-risk behavior tendencies, including medically high-risk participants recruited from psychiatric clinics. Risk tendencies were assessed using the Adolescent Risk Behavior Screen (ARBS). ARBS risk scores correlated highly (0.78) with impulsivity scores from the Barratt Impulsivity scale (BIS). Participants underwent 4.7 Tesla functional magnetic resonance imaging (fMRI) while performing an emotional Go/NoGo task. This task presented an aversive or neutral distractor image simultaneously with each Go or NoGo stimulus. Risk behavior and impulsivity tendencies exhibited similar but not identical associations with fMRI activation patterns in prefrontal brain regions. We interpret these results as reflecting differences in response inhibition, emotional stimulus processing, and emotion regulation in relation to participant risk behavior tendencies and impulsivity levels. The results are consistent with high impulsivity playing an important role in determining high risk tendencies in this sample containing clinically high-risk adolescents.

M5TM alloy high burnup behavior and worldwide licensing

International Nuclear Information System (INIS)

Mardon, J.P.; Hoffmann, P.B.; Garner, G.L.

2005-01-01

The in-reactor behavior of advanced PWR Zirconium alloys at burnups equal to or below licensing limits has been widely reported. Specifically, the advanced alloy M5 has demonstrated impressive improvements over Zircaloy-4 for fuel rod cladding and fuel assembly structural components. To demonstrate superiority of the alloy at burnups beyond current licensing limits, M5 has been operated in PWR at burnups exceeding 71 GWd/tU in the United States and 78 GWd/tU in Europe. Two extensive irradiation programs have been performed in the United States to demonstrate alloy M5 performance beyond current licensing limits. Four M5 TM fuel rods were exposed to four 24-month cycles in a 15x15 reactor beginning in 1995. Additionally, one 17x17 lead assembly containing M5 fuel rods and guide tubes was operated for four 18-month cycles beginning from 1997. Post-irradiation examinations (PIE) performed after all four cycles in the 15x15 demonstration program revealed excellent performance in the licensed burnup and in the high burnup stages of the experience. Examination of the 4th cycle 17x17 assembly will be accomplished in two stages the first of which is scheduled for June 2005. Moreover, several irradiation campaigns have been performed in Europe in order to confirm the excellent M5 in-pile behavior in demanding PWRs irradiation conditions with regard to void fraction, heat flux, lithium content and temperature. Results from the high burnup fuel examinations verify that the excellent performance achieved up to 62 GWd/tU was continued into higher burnup. The results of high burnup PIE campaigns for European and American PWR's are presented in this paper. Measured performance indicators include fuel assembly dimensional stability parameters (assembly length, fuel rod length, assembly bow, fuel rod bow, fuel rod radial creep and spacer grid width), oxidation measurements (fuel rod and guide tube) and hydrogen pick-up data (fuel rod). In the framework of PCI studies, power ramp

Structure and behavior as determinants: United States nuclear test ban and chemical and biological arms control policy

International Nuclear Information System (INIS)

Reich, J.C.

1991-01-01

US efforts to control chemical and biological warfare and nuclear testing are examined with the aim of explaining the paucity of US backed agreements in these areas. Two theoretical perspectives, the behavioral and structural approaches, are used to explore US arms control outcomes. In the behavioral approach, the effects of governmental organization and the bargaining dynamics of policy-making elites with different cognitive styles are posited as important influences on US nuclear test ban and chemical and biological arms control policy outcomes. The behavioral perspective accounts for the timing of all US failed and successful entries (with one exception) into nuclear test bans and chemical and biological warfare restraints. A shortcoming of the behavior approach, however, is that it tends to overemphasize the chances for successful US entry into nuclear test and chemical and biological warfare limitations. Analysis of the same events from the structural perspective helps to correct for expectations generated by behavioral variables for a higher success rate than ultimately resulted. In the structural approach, the focus is on the effect of the organization of international politics on US nuclear test ban and chemical and biological arms control policy outcomes

Leaching behavior of simulated high-level waste glass

International Nuclear Information System (INIS)

Kamizono, Hiroshi

1987-03-01

The author's work in the study on the leaching behavior of simulated high-level waste (HLW) glass were summarized. The subjects described are (1) leach rates at high temperatures, (2) effects of cracks on leach rates, (3) effects of flow rate on leach rates, and (4) an in-situ burial test in natural groundwater. In the following section, the leach rates obtained by various experiments were summarized and discussed. (author)

Evaluation of seismic behavior of soils under nuclear containment structures via dynamic centrifuge test

Energy Technology Data Exchange (ETDEWEB)

Ha, Jeong Gon, E-mail: jgha87@kaist.ac.kr; Kim, Dong-Soo, E-mail: dskim@kaist.ac.kr

2014-10-01

Highlights: • A series of dynamic centrifuge tests were performed for NPP structure to investigate the soil–foundation-structure interaction with various soil conditions from loose sand to weathered rock. • SFSI phenomena for NPP structure were observed directly using experimental method. • Effect of the soil stiffness and nonlinear characteristics on SFSI was estimated. • There are comparisons of the control motions for seismic design of a NPP structure. • Subsoil condition, earthquake intensity and control motion affected to seismic load. - Abstract: To evaluate the earthquake loads for the seismic design of a nuclear containment structure, it is necessary to consider the soil–foundation-structure interaction (SFSI) due to their interdependent behavior. Especially, understanding the effects of soil stiffness under the structure and the location of control motion to SFSI are very important. Motivated by these requirements, a series of dynamic centrifuge tests were performed with various soil conditions from loose sand to weathered rock (WR), as well as different seismic intensities for the bedrock motion. The different amplification characteristics in peak-accelerations profile and effects of soil-nonlinearity in response spectrum were observed. The dynamic behaviors were compared between surface of free-field and foundation of the structure for the evaluation of the control motion for seismic design. It was found that dynamic centrifuge test has potentials to estimate the seismic load considering SFSI.

Evaluation of seismic behavior of soils under nuclear containment structures via dynamic centrifuge test

International Nuclear Information System (INIS)

Ha, Jeong Gon; Kim, Dong-Soo

2014-01-01

Highlights: • A series of dynamic centrifuge tests were performed for NPP structure to investigate the soil–foundation-structure interaction with various soil conditions from loose sand to weathered rock. • SFSI phenomena for NPP structure were observed directly using experimental method. • Effect of the soil stiffness and nonlinear characteristics on SFSI was estimated. • There are comparisons of the control motions for seismic design of a NPP structure. • Subsoil condition, earthquake intensity and control motion affected to seismic load. - Abstract: To evaluate the earthquake loads for the seismic design of a nuclear containment structure, it is necessary to consider the soil–foundation-structure interaction (SFSI) due to their interdependent behavior. Especially, understanding the effects of soil stiffness under the structure and the location of control motion to SFSI are very important. Motivated by these requirements, a series of dynamic centrifuge tests were performed with various soil conditions from loose sand to weathered rock (WR), as well as different seismic intensities for the bedrock motion. The different amplification characteristics in peak-accelerations profile and effects of soil-nonlinearity in response spectrum were observed. The dynamic behaviors were compared between surface of free-field and foundation of the structure for the evaluation of the control motion for seismic design. It was found that dynamic centrifuge test has potentials to estimate the seismic load considering SFSI

Structure functions in the chiral bag model

International Nuclear Information System (INIS)

Sanjose, V.; Vento, V.; Centro Mixto CSIC/Valencia Univ., Valencia

1989-01-01

We calculate the structure functions of an isoscalar nuclear target for the deep inelastic scattering by leptons in an extended version of the chiral bag model which incorporates the qanti q structure of the pions in the cloud. Bjorken scaling and Regge behavior are satisfied. The model calculation reproduces the low-x behavior of the data but fails to explain the medium- to large-x behavior. Evolution of the quark structure functions seem inevitable to attempt a connection between the low-energy models and the high-energy behavior of quantum chromodynamics. (orig.)

Structure functions in the chiral bag model

Energy Technology Data Exchange (ETDEWEB)

Sanjose, V.; Vento, V.

1989-07-13

We calculate the structure functions of an isoscalar nuclear target for the deep inelastic scattering by leptons in an extended version of the chiral bag model which incorporates the qanti q structure of the pions in the cloud. Bjorken scaling and Regge behavior are satisfied. The model calculation reproduces the low-x behavior of the data but fails to explain the medium- to large-x behavior. Evolution of the quark structure functions seem inevitable to attempt a connection between the low-energy models and the high-energy behavior of quantum chromodynamics. (orig.).

High performance as-grown and annealed high band gap tunnel junctions: Te behavior at the interface

Energy Technology Data Exchange (ETDEWEB)

Bedair, S. M., E-mail: bedair@ncsu.edu; Harmon, Jeffrey L.; Carlin, C. Zachary; Hashem Sayed, Islam E.; Colter, P. C. [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

2016-05-16

The performance of n{sup +}-InGaP(Te)/p{sup +}-AlGaAs(C) high band gap tunnel junctions (TJ) is critical for achieving high efficiency in multijunction photovoltaics. Several limitations for as grown and annealed TJ can be attributed to the Te doping of InGaP and its behavior at the junction interface. Te atoms in InGaP tend to get attached at step edges, resulting in a Te memory effect. In this work, we use the peak tunneling current (J{sub pk}) in this TJ as a diagnostic tool to study the behavior of the Te dopant at the TJ interface. Additionally, we used our understanding of Te behavior at the interface, guided by device modeling, to modify the Te source shut-off procedure and the growth rate. These modifications lead to a record performance for both the as-grown (2000 A/cm{sup 2}) and annealed (1000 A/cm{sup 2}) high band gap tunnel junction.

Effect of Cross-linking Density on Creep and Recovery Behavior in Epoxy-Based Shape Memory Polymers (SMEPs) for Structural Applications

Science.gov (United States)

Rao, Kavitha V.; Ananthapadmanabha, G. S.; Dayananda, G. N.

2016-12-01

Epoxy-based shape memory polymers (SMEPs) are gaining importance in the area of aerospace structures due to their high strength and stiffness which is a primary requirement for an SMEP in structural applications. The understanding of viscoelastic behavior of SMEPs is very essential to assess their shape memory effect. In the present work, three types of SMEPs with varying cross-linking densities were developed by curing an aromatic epoxy resin with aliphatic amines. Glass transition temperature ( T g) was measured for these SMEPs using advanced rheometric expansion system, and from the T g measurements, a range of temperatures from glassy to rubbery regimes were chosen. At selected temperatures, creep-recovery tests were performed in order to evaluate the viscoelastic behavior of SMEPs and also to investigate the effect of temperature on creep-recovery. Further, a three-parameter viscoelastic model (Zener) was used to fit the data obtained from experiments. Model parameters like moduli of the springs and viscosity of the dashpot were evaluated by curve fitting. Results revealed that Zener model was well suited to describe the viscoelastic behavior of SMEPs as a function of test temperatures.

Electronic structure of ion arsenic high temperature superconductors studied by angle resolved photoemission spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Liu, Chang [Iowa State Univ., Ames, IA (United States)

2011-01-01

The main purpose of the present thesis is to present our ARPES results on the iron arsenic superconductors. As revealed by a series of ARPES measurements on both the AEFe2As2 and the RFeAs(O,F) families (parent compound and carrier-doped systems), the electronic structures of the pnictides are complicated, three dimensional, and closely linked to their superconducting behavior (13; 14; 15; 16; 17; 18; 19). Parent compounds of these materials exhibit the basic hole-electron pocket dual plus an apparent Fermi surface reconstruction caused by long range antiferromagnetism (13; 15). When carriers are introduced, the chemical potential shifts in accordance with the Luttinger theorem and the rigid band shifting picture (13). Importantly, both the appearance and disappearance of the superconducting dome at low and high doping levels have intimate relation with topological changes at the Fermi surfaces, resulting in a specific Fermi topology being favored by superconductivity (15; 16). On the low doping side, superconductivity emerges in the phase diagram once the antiferromagnetic reconstruction disappears below the Fermi level, returning the Fermi surface to its paramagnetic-like appearance. On the high doping side, superconductivity disappears around a doping level at which the central hole pocket vanishes due to increasing electron concentration. Such phenomena are evidence for the governing role the electronic structure plays in their superconducting behavior.

Improved method to demonstrate the structural integrity of high density fuel storage racks

International Nuclear Information System (INIS)

Hinderks, M.; Ungoreit, H.; Kremer, G.

2001-01-01

Reracking of existing fuel pools to the maximum extent is desirable from an economical point of view. This goal can be achieved by minimizing the gaps between the spent fuel storage racks. Since the rack design is aimed at enabling consolidated fuel rod storage, additional requirements arise with respect to the design and the structural analysis. The loads resulting from seismic events are decisive for the structural analysis and require a specially detailed and in-depth analysis for high seismic loads. The verification of structural integrity and functionality is performed in two phases. In the first phase the motional behavior of single racks, rows of racks and, where required, of all racks in the pool is simulated by excitation with displacement time histories under consideration of the fluid-structure interaction (FSI). The displacements from these simulations are evaluated, while the loads are utilized as input data for the structural analysis of the racks and the pool floor. The structural analyses for the racks comprise substantially stress analyses for base material and welds as well as stability analyses for the support channels and the rack outside walls. The analyses are performed in accordance with the specified codes and standards

Effects of reinforcement ratio and arrangement on the structural behavior of a nuclear building under aircraft impact

International Nuclear Information System (INIS)

Thai, Duc-Kien; Kim, Seung-Eock; Lee, Hyuk-Kee

2014-01-01

Highlights: • Numerical analysis of RC nuclear building model under aircraft impact was conducted. • The analysis result shows similar behavior as compared to the Riera function. • The effects of reinforcement ratio and arrangement were enumerated. • The appropriate number of layer of longitudinal rebar was recommended. - Abstract: This study presents the effectiveness of the rebar ratio and the arrangement of reinforced concrete (RC) structures on the structural behavior of nuclear buildings under aircraft impact using a finite element (FE) approach. A simplified model of a fictitious nuclear building using RC structures was fully modeled. The aircraft model of a Boeing 767-400 was used for impact simulation and was developed and verified with a conventional impact force–time history curve. The IRIS Punching test was used to validate the damage prediction capabilities of the RC wall under impact loading. With regard to the different rebar ratios and rebar arrangements of a nuclear RC building, the structural behavior of a building under aircraft impact was investigated. The structural behavior investigated included plastic deformation, displacement, energy dissipation, perforation/penetration depth and scabbing area. The results showed that the rebar ratio has a significant effect on withstanding aircraft impact and reducing local damage. With four layers of rebar, the RC wall absorbed and dissipated the impact energy more than once with only two layers of rebar for the same rebar ratio

Turbulent times: effects of turbulence and violence exposure in adolescence on high school completion, health risk behavior, and mental health in young adulthood.

Science.gov (United States)

Boynton-Jarrett, Renée; Hair, Elizabeth; Zuckerman, Barry

2013-10-01

Turbulent social environments are associated with health and developmental risk, yet mechanisms have been understudied. Guided by a life course framework and stress theory, this study examined the association between turbulent life transitions (including frequent residential mobility, school transitions, family structure disruptions, and homelessness) and exposure to violence during adolescence and high school completion, mental health, and health risk behaviors in young adulthood. Participants (n = 4834) from the U.S. National Longitudinal Survey of Youth, 1997 cohort were followed prospectively from age 12-14 years for 10 years. We used structural equation models to investigate pathways between turbulence and cumulative exposure to violence (CEV), and high school completion, mental health, and health risk behaviors, while accounting for early life socio-demographics, family processes, and individual characteristics. Results indicated that turbulence index was associated with cumulative exposure to violence in adolescence. Both turbulence index and cumulative exposure to violence were positively associated with higher health risk behavior, poorer mental health, and inversely associated with high school completion. These findings highlight the importance of considering the cumulative impact of turbulent and adverse social environments when developing interventions to optimize health and developmental trajectory for adolescents transitioning into adulthood. Copyright © 2012 Elsevier Ltd. All rights reserved.

Collective, stochastic and nonequilibrium behavior of highly excited hadronic matter

Energy Technology Data Exchange (ETDEWEB)

Carruthers, P [Los Alamos National Lab., NM (USA). Theoretical Div.

1984-04-23

We discuss selected problems concerning the dynamics and stochastic behavior of highly excited matter, particularly the QCD plasma. For the latter we consider the equation of state, kinetics, quasiparticles, flow properties and possible chaos and turbulence. The promise of phase space distribution functions for covariant transport and kinetic theory is stressed. The possibility and implications of a stochastic bag are spelled out. A simplified space-time model of hadronic collisions is pursued, with applications to A-A collisions and other matters. The domain wall between hadronic and plasma phase is of potential importance: its thickness and relation to surface tension is noticed. Finally, we review the recently developed stochastic cell model of multiparticle distributions and KNO scaling. This topic leads to the notion that fractional dimensions are involved in a rather general dynamical context. We speculate that various scaling phenomena are independent of the full dynamical structure, depending only on a general stochastic framework having to do with simple maps and strange attractors. 42 refs.

Collective, stochastic and nonequilibrium behavior of highly excited hadronic matter

International Nuclear Information System (INIS)

Carruthers, P.

1983-01-01

We discuss selected problems concerning the dynamic and stochasticc behavior of highly excited matter, particularly the QCD plasma. For the latter we consider the equation of state, kinetics, quasiparticles, flow properties and possible chaos and turbulence. The promise of phase space distribution functions for covariant transport and kinetic theory is stressed. The possibility and implications of a stochastic bag are spelled out. A simplified space-time model of hadronic collisions is pursued, with applications to A-A collisions and other matters. The domain wall between hadronic and plasma phase is of potential importance: its thickness and relation to surface tension are noticed. Finally we reviewed the recently developed stochastic cell model of multiparticle distributions and KNO scaling. This topic leads to the notion that fractal dimensions are involved in a rather general dynamical context. We speculate that various scaling phenomena are independent of the full dynamical structure, depending only on a general stochastic framework having to do with simple maps and strange attractors. 42 references

The cheater's high: the unexpected affective benefits of unethical behavior.

Science.gov (United States)

Ruedy, Nicole E; Moore, Celia; Gino, Francesca; Schweitzer, Maurice E

2013-10-01

Many theories of moral behavior assume that unethical behavior triggers negative affect. In this article, we challenge this assumption and demonstrate that unethical behavior can trigger positive affect, which we term a "cheater's high." Across 6 studies, we find that even though individuals predict they will feel guilty and have increased levels of negative affect after engaging in unethical behavior (Studies 1a and 1b), individuals who cheat on different problem-solving tasks consistently experience more positive affect than those who do not (Studies 2-5). We find that this heightened positive affect does not depend on self-selection (Studies 3 and 4), and it is not due to the accrual of undeserved financial rewards (Study 4). Cheating is associated with feelings of self-satisfaction, and the boost in positive affect from cheating persists even when prospects for self-deception about unethical behavior are reduced (Study 5). Our results have important implications for models of ethical decision making, moral behavior, and self-regulatory theory.

Structural Behaviors of Reinforced Concrete Piers Rehabilitated with FRP Wraps

Directory of Open Access Journals (Sweden)

Junsuk Kang

2017-01-01

Full Text Available The use of fiber-reinforced polymer (FRP wraps to retrofit and strengthen existing structures such as reinforced concrete piers is becoming popular due to the higher tensile strength, durability, and flexibility gained and the method’s ease of handling and low installation and maintenance costs. As yet, however, few guidelines have been developed for determining the optimum thicknesses of the FRP wraps applied to external surfaces of concrete or masonry structures. In this study, nonlinear pushover finite element analyses were utilized to analyze the complex structural behaviors of FRP-wrapped reinforced rectangular piers. Design parameters such as pier section sizes, pier heights, pier cap lengths, compressive strengths of concrete, and the thicknesses of the FRP wraps used were thoroughly tested under incremental lateral and vertical loads. The results provide useful guidelines for analyzing and designing appropriate FRP wraps for existing concrete piers.

On the consistency and high-energy behavior of string theory

International Nuclear Information System (INIS)

Mende, P.F.

1988-01-01

In Part I, it is shown that the heterotic string is free of gauge and gravitational anomalies by showing that (a) unless the gauge group is E S x E S or Spin(32)/Z 2 or a subgroup, the internal sector partition function vanishes so there is no consistent theory; and (b) for E 8 x E 8 and Spin(32)/Z 2 compactifications, the longitudinal modes of the massless gauge particles decouple, as required by gauge invariance. We discuss the geometric interpretation for string theory when the action is invariant under a modular subgroup. In Part II, the high-energy behavior of string scattering amplitudes is studied to all orders in perturbation theory, with the aim of exploring the short-distance structure of string theory. It is shown that the sum over all Riemann surfaces is dominated by a saddle point. Consequently, the high-energy limit is universal and simple to calculate. In this limit the amplitudes fall off much faster than allowed by field theory. The dominant saddle points are identified as coming from world sheets which are Z G+1 symmetric algebraic curves, and their contribution to the scattering amplitude is evaluated for the bosonic to all orders and for the heterotic string to two-loop order. An interesting spacetime picture of the high-energy limit emerges. The issue of summing the perturbation expansion is addressed

Emotion and cognition in high and low stress sensitive mouse strains: a combined neuroendocrine and behavioral study in BALB/c and C57BL/6J mice

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Vera Brinks

2007-12-01

Full Text Available Emotionally arousing experiences and stress influence cognitive processes and vice versa. Understanding the relations and interactions between these three systems forms the core of this study. We tested two inbred mouse strains (BALB/c, C57BL/6J; male; 3-month-old for glucocorticoid stress system markers (expression of MR and GR mRNA and protein in hippocampus, amygdala, and prefrontal cortex; blood plasma corticosterone, used behavioral tasks for emotions and cognitive performance (elevated plus maze, holeboard to assess the interdependence of these factors. We hypothesize that BALB/c mice have a stress-vulnerable neuroendocrine phenotype and that emotional expressions in BALB/c and C57BL/6J mice will differentially contribute to learning and memory. We applied factor analyses on emotional and cognitive parameters to determine the behavioral structure of BALB/c and C57BL/6J mice. Glucocorticoid stress system markers indeed show that BALB/c mice are more stress-vulnerable than C57BL/6J mice. Moreover, emotional and explorative factors differed between naïve BALB/c and C57BL/6J mice. BALB/c mice display high movement in anxiogenic zones and high risk assessment, while C57BL/6J mice show little movement in anxiogenic zones and display high vertical exploration. Furthermore, BALB/c mice are superior learners, showing learning related behavior which is highly structured and emotionally biased when exposed to a novel or changing situation. In contrast, C57BL/6J mice display a rather ‘‘chaotic’’ behavioral structure during learning in absence of an emotional factor. These results show that stress vulnerability coincides with more emotionality, which drives well orchestrated goal directed behavior to the benefit of cognition. Both phenotypes have their advantage depending on environmental demands.

Bat guilds, a concept to classify the highly diverse foraging and echolocation behaviors of microchiropteran bats

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Annette eDenzinger

2013-07-01

Full Text Available Throughout evolution the foraging and echolocation behaviors as well as the motor systems of bats have been adapted to the tasks they have to perform while searching and acquiring food. When bats exploit the same class of environmental resources in a similar way, they perform comparable tasks and thus share similar adaptations independent of their phylogeny. Species with similar adaptations are assigned to guilds or functional groups. Habitat type and foraging mode mainly determine the foraging tasks and thus the adaptations of bats. Therefore we use habitat type and foraging mode to define seven guilds. The habitat types open, edge and narrow space are defined according to the bats’ echolocation behavior in relation to the distance between bat and background or food item and background. Bats foraging in the aerial, trawling, flutter detecting, or active gleaning mode use only echolocation to acquire their food. When foraging in the passive gleaning mode bats do not use echolocation but rely on sensory cues from the food item to find it. Bat communities often comprise large numbers of species with a high diversity in foraging areas, foraging modes, and diets. The assignment of species living under similar constraints into guilds identifies pattern of community structure and helps to understand the factors that underlie the organization of highly diverse bat communities. Bat species from different guilds do not compete for food as they differ in their foraging behavior and in the environmental resources they use. However, sympatric living species belonging to the same guild often exploit the same class of resources. To avoid competition they should differ in their niche dimensions. The fine grain structure of bat communities below the rather coarse classification into guilds is determined by mechanisms that result in niche partitioning.

Differences in structure and magnetic behavior of Mn-AlN films due to substrate material

International Nuclear Information System (INIS)

Sato, Takanobu; Nakatani, Ryoichi; Endo, Yasushi; Kirino, Fumiyoshi

2009-01-01

The structure and magnetic behavior of Mn-AlN (Al 1-x Mn x N, x = 0.03, 0.04) films deposited on thermally oxidized Si (001) substrates and sapphire (0001) substrates were studied. Mn-AlN films deposited on each substrate had a wuertzite-type AlN phase with a preferentially oriented c-axis. Mn-AlN films that were deposited on Si (001) substrate exhibited paramagnetic behavior. In addition to paramagnetic behavior, weak ferromagnetic behavior with curie temperatures higher than room temperature were observed for Mn-AlN films deposited on sapphire (0001) substrates.

Structure and wear behavior of AlCrSiN-based coatings

Energy Technology Data Exchange (ETDEWEB)

Chen, Yun [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Chengdu Tool Research Institute Co., Ltd., Chengdu 610500 (China); Du, Hao [School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065 (China); Chen, Ming, E-mail: mchen@sjtu.edu.cn [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Yang, Jun [Chengdu Tool Research Institute Co., Ltd., Chengdu 610500 (China); Xiong, Ji [School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065 (China); Zhao, Haibo [The Analysis and Testing Centre, Sichuan University, Chengdu 610065 (China)

2016-05-01

Graphical abstract: - Highlights: • AlCrSiN based coating showed amorphous structure. • AlCrSiN/Me{sub x}N coatings obtained better wear resistance. • Molybdenum and niobium increased the coating hardness and wear resistance. - Abstract: AlCrN, AlCrSiCN, AlCrSiN/MoN, and AlCrSiN/NbN coatings have been deposited on high-polished WC–Co cemented carbide substrate and tools by mid-frequency magnetron sputtering in Ar/N{sub 2} mixtures. Al{sub 0.6}Cr{sub 0.4}, Al{sub 0.6}Cr{sub 0.3}Si{sub 0.1}, and C/Mo/Nb targets were used during the deposition. The microstructure and mechanical properties of as-deposited coatings were investigated. Investigations of the wear behaviors of coated tools were also performed. The results showed that cubic structure was formed in the coatings. Broader CrAlN (1 1 1) and (2 0 0) peaks without SiN{sub x} peak were formed in the AlCrSiN/Me{sub x}N coatings, which showed a nanocomposited structure. Meanwhile, according to SEM micrographs, AlCrN exhibited a columnar structure, while, AlCrSiCN, AlCrSiN/MoN, and AlCrSiN/NbN coatings showed nanocrystalline morphology. The nano-multilayered coatings performed higher hardness, H/E, and H{sup 3}/E{sup 2} ratios compared with AlCrN coating. Through the Rockwell adhesion test, all the coatings exhibited adhesion strength quality HF1. After turning Inconel 718 under dry condition, the nano-multilyered coatings showed better wear resistance than AlCrN coating. Due to the molybdenum and niobium in the coating, AlCrSiN/MoN and AlCrSiN/NbN coatings showed the best wear resistance.

Optical and structural behaviors of crosslinked polyvinyl alcohol thin films

Science.gov (United States)

Pandit, Subhankar; Kundu, Sarathi

2018-04-01

Polyvinyl Alcohol (PVA) has excellent properties like uniaxial tensile stress, chemical resistance, biocompatibility, etc. The properties of PVA further can be tuned by crosslinking process. In this work, a simple heat treatment method is used to find out the optimum crosslinking of PVA and the corresponding structural and optical responses are explored. The PVA crosslinking is done by exposing the films at different temperatures and time intervals. The optical property of pure and heat treated PVA films are investigated by UV-Vis absorption and photoluminescence emission spectroscopy and structural modifications are studied by Fourier Transform Infrared Spectroscopy (FTIR). The absorption peaks of pure PVA are observed at ≈ 280 and 335 nm and the corresponding emission is observed at ≈ 424 nm. The pure PVA showed modified optical behaviors after the heat treatment. In addition, dipping the PVA films in hot water (85°C) for nearly 20 minutes also show impact on both structural and optical properties. From FTIR spectroscopy, the changes in vibrational band positions confirm the structural modifications of PVA films.

High-Risk Health and Credit Behavior among 18- to 25-Year-Old College Students

Science.gov (United States)

Adams, Troy; Moore, Monique

2007-01-01

The number of students accumulating credit card debt--and the amount of debt itself--on college campuses is increasing. If high-risk credit and health behavior are associated, health behavior interventions might apply to high-risk credit behavior. Objective: The authors' purpose was to examine these possible associations. Participants and Methods:…

Brain Genomics Superstruct Project initial data release with structural, functional, and behavioral measures.

Science.gov (United States)

Holmes, Avram J; Hollinshead, Marisa O; O'Keefe, Timothy M; Petrov, Victor I; Fariello, Gabriele R; Wald, Lawrence L; Fischl, Bruce; Rosen, Bruce R; Mair, Ross W; Roffman, Joshua L; Smoller, Jordan W; Buckner, Randy L

2015-01-01

The goal of the Brain Genomics Superstruct Project (GSP) is to enable large-scale exploration of the links between brain function, behavior, and ultimately genetic variation. To provide the broader scientific community data to probe these associations, a repository of structural and functional magnetic resonance imaging (MRI) scans linked to genetic information was constructed from a sample of healthy individuals. The initial release, detailed in the present manuscript, encompasses quality screened cross-sectional data from 1,570 participants ages 18 to 35 years who were scanned with MRI and completed demographic and health questionnaires. Personality and cognitive measures were obtained on a subset of participants. Each dataset contains a T1-weighted structural MRI scan and either one (n=1,570) or two (n=1,139) resting state functional MRI scans. Test-retest reliability datasets are included from 69 participants scanned within six months of their initial visit. For the majority of participants self-report behavioral and cognitive measures are included (n=926 and n=892 respectively). Analyses of data quality, structure, function, personality, and cognition are presented to demonstrate the dataset's utility.

Structural characteristics and corrosion behavior of biodegradable Mg-Zn, Mg-Zn-Gd alloys.

Science.gov (United States)

Kubásek, J; Vojtěch, D

2013-07-01

In this research, binary Mg-Zn (up to 3 wt% Zn) and ternary Mg-Zn-Gd (up to 3 wt% Gd, 3 wt% Zn) alloys were prepared by induction melting in an argon atmosphere. The structures of these alloys were characterized using light and scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction and X-ray fluorescence. In addition, Brinell hardness measurements were taken to supplement these studies. Corrosion behavior was evaluated by immersion tests and potentiodynamic measurements in a physiological solution (9 g/l NaCl). Depending on the composition, structures of the as-cast alloys contained α-Mg dendrites, MgZn, Mg5Gd and Mg3Gd2Zn3 phases. Compared to pure Mg, zinc improved the corrosion resistance of binary Mg-Zn. Gadolinium also improved the corrosion resistance in the case of Mg-1Zn-3Gd alloy. The highest corrosion rate was observed for Mg-3Zn-3Gd alloy. Our results improve the understanding of the relationships between the structure and corrosion behavior of our studied alloy systems.

Tax evasion under behavioral structures

Directory of Open Access Journals (Sweden)

Gabriela S. Pantoja

2014-01-01

Full Text Available We study the strategic interactions between the fiscal authority and the taxpayer regarding tax evasion and auditing. We fit this interaction into a Bayesian game and introduce the concept of behavioral consistency, which helps reducing the number of available strategies and models the stylized fact according to which the choice to evade is subject to behavioral patterns.

Sensitivity Analysis of the Influence of Structural Parameters on Dynamic Behaviour of Highly Redundant Cable-Stayed Bridges

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B. Asgari

2013-01-01

Full Text Available The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.

Bioinspired Nanocomposite Hydrogels with Highly Ordered Structures.

Science.gov (United States)

Zhao, Ziguang; Fang, Ruochen; Rong, Qinfeng; Liu, Mingjie

2017-12-01

In the human body, many soft tissues with hierarchically ordered composite structures, such as cartilage, skeletal muscle, the corneas, and blood vessels, exhibit highly anisotropic mechanical strength and functionality to adapt to complex environments. In artificial soft materials, hydrogels are analogous to these biological soft tissues due to their "soft and wet" properties, their biocompatibility, and their elastic performance. However, conventional hydrogel materials with unordered homogeneous structures inevitably lack high mechanical properties and anisotropic functional performances; thus, their further application is limited. Inspired by biological soft tissues with well-ordered structures, researchers have increasingly investigated highly ordered nanocomposite hydrogels as functional biological engineering soft materials with unique mechanical, optical, and biological properties. These hydrogels incorporate long-range ordered nanocomposite structures within hydrogel network matrixes. Here, the critical design criteria and the state-of-the-art fabrication strategies of nanocomposite hydrogels with highly ordered structures are systemically reviewed. Then, recent progress in applications in the fields of soft actuators, tissue engineering, and sensors is highlighted. The future development and prospective application of highly ordered nanocomposite hydrogels are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DASH - Youth Risk Behavior Surveillance System (YRBSS): High School - Excluding Sexual Identity

Data.gov (United States)

U.S. Department of Health & Human Services — 1991-2015. High School Dataset. The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health behaviors among youth and young...

Multimodal Behavior Therapy: Case Study of a High School Student.

Science.gov (United States)

Seligman, Linda

1981-01-01

A case study of a high school student concerned with weight problems illustrates multimodal behavior therapy and its use in a high school setting. Multimodal therapy allows the school counselor to maximize referral sources while emphasizing growth and actualization. (JAC)

Ultrathin nickel hydroxide on carbon coated 3D-porous copper structures for high performance supercapacitors.

Science.gov (United States)

Kang, Kyeong-Nam; Kim, Ik-Hee; Ramadoss, Ananthakumar; Kim, Sun-I; Yoon, Jong-Chul; Jang, Ji-Hyun

2018-01-03

An ultrathin nickel hydroxide layer electrodeposited on a carbon-coated three-dimensional porous copper structure (3D-C/Cu) is suggested as an additive and binder-free conductive electrode with short electron path distances, large electrochemical active sites, and improved structural stability, for high performance supercapacitors. The 3D-porous copper structure (3D-Cu) provides high electrical conductivity and facilitates electron transport between the Ni(OH) 2 active materials and the current collector of the Ni-plate. A carbon coating was applied to the 3D-Cu to prevent the oxidation of Cu, without degrading the electron transport behavior of the 3D-Cu. The 3D-Ni(OH) 2 /C/Cu exhibited a high specific capacitance of 1860 F g -1 at 1 A g -1 , and good cycling performance, with an 86.5% capacitance retention after 10 000 cycles. When tested in a two-electrode system, an asymmetric supercapacitor exhibited an energy density of 147.9 W h kg -1 and a power density of 37.0 kW kg -1 . These results open a new area of ultrahigh-performance supercapacitors, supported by 3D-Cu electrodes.

Influence of reinforcement type on the mechanical behavior and fire response of hybrid composites and sandwich structures

Science.gov (United States)

Giancaspro, James William

Lightweight composites and structural sandwich panels are commonly used in marine and aerospace applications. Using carbon, glass, and a host of other high strength fiber types, a broad range of laminate composites and sandwich panels can be developed. Hybrid composites can be constructed by laminating multiple layers of varying fiber types while sandwich panels are manufactured by laminating rigid fiber facings onto a lightweight core. However, the lack of fire resistance of the polymers used for the fabrication remains a very important problem. The research presented in this dissertation deals with an inorganic matrix (Geopolymer) that can be used to manufacture laminate composites and sandwich panels that are resistant up to 1000°C. This dissertation deals with the influence of fiber type on the mechanical behavior and the fire response of hybrid composites and sandwich structures manufactured using this resin. The results are categorized into the following distinct studies. (i) High strength carbon fibers were combined with low cost E-glass fibers to obtain hybrid laminate composites that are both economical and strong. The E-glass fabrics were used as a core while the carbon fibers were placed on the tension face and on both tension and compression faces. (ii) Structural sandwich beams were developed by laminating various types of reinforcement onto the tension and compression faces of balsa wood cores. The flexural behavior of the beams was then analyzed and compared to beams reinforced with organic composite. The effect of core density was evaluated using oak beams reinforced with inorganic composite. (iii) To measure the fire response, balsa wood sandwich panels were manufactured using a thin layer of a fire-resistant paste to serve for fire protection. Seventeen sandwich panels were fabricated and tested to measure the heat release rates and smoke-generating characteristics. The results indicate that Geopolymer can be effectively used to fabricate both

Structural properties and gas sensing behavior of sol-gel grown nanostructured zinc oxide

Energy Technology Data Exchange (ETDEWEB)

Rajyaguru, Bhargav; Gadani, Keval; Kansara, S. B.; Pandya, D. D.; Shah, N. A.; Solanki, P. S., E-mail: piyush.physics@gmail.com [Department of Physics, Saurashtra University, Rajkot – 360 005 (India); Rathod, K. N.; Solanki, Sapana [Department of Physics, Saurashtra University, Rajkot – 360 005 (India); V.V.P. Engineering College, Gujarat Technological University, Rajkot – 360 005 (India)

2016-05-06

In this communication, we report the results of the studies on structural properties and gas sensing behavior of nanostructured ZnO grown using acetone precursor based modified sol-gel technique. Final product of ZnO was sintered at different temperatures to vary the crystallite size while their structural properties have been studied using X-ray diffraction (XRD) measurement performed at room temperature. XRD results suggest the single phasic nature of all the samples and crystallite size increases from 11.53 to 20.96 nm with increase in sintering temperature. Gas sensing behavior has been studied for acetone gas which indicates that lower sintered samples are more capable to sense the acetone gas and related mechanism has been discussed in the light of crystallite size, crystal boundary density, defect mechanism and possible chemical reaction between gas traces and various oxygen species.

The relationship between whistleblowing and organizational citizenship behavior for high school teachers

Directory of Open Access Journals (Sweden)

Abbas ERTÜRK

2016-04-01

Full Text Available The purpose of this study is to examine the relationship between whistleblowing and organizational citizenship behaviors in high school teachers. The research was conducted using the screening model. A total of 381 teachers participated in the research from general and vocational high schools. 216 (56.7% of them were male and 165 (43.3% were female. The "Whistleblowing Scale" and "Organizational Citizenship Scale" were used to collect the data. Descriptive statistics, t-test and ANOVA were used in the data analysis. The Scheffe test was used for the comparison of multiple tests in order to determine the source of the difference for the F values. Pearson correlation analysis was used to determine the relation between the level of organizational citizenship behavior and whistleblowing. The results were tested at the level of p<.01 and p<.05. The survey findings indicate that the teachers’ level of whistleblowing behavior is moderate and that males are whistleblowers significantly more than females, and that there is no significant difference between the groups in terms of the type of school. The teachers’ level of organizational citizenship behavior was high and does not differ according to gender, but significantly differs according to the type of school in favor of vocational schools. In addition, correlation analysis indicates a positive and significant relationship between teachers' whistleblowing behavior and organizational citizenship behavior at a low level.

Semantic structures of world image as internal factors in the self-destructive behavior of today’s teenagers.

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Koroleva N.N.

2015-03-01

Full Text Available This article presents the results of a theoretical and methodological analysis and empirical study of semantic formations in the structure of a world image as factors in teenagers’ self-destructive behavior in contemporary Russian society. During the teenage years the value-semantic bases of a world image are being formed. A world image is the integral, multilevel representation of the subject, which consists of social reality and himself/herself; it exists in the mind as a unity of sensual fabrications, significations, and personalized meanings. Transformations of semantic components of a world image that are inadequate for the environment or that are externally and internally rigid can serve as preconditions for disadaptation and for one of its extreme forms—self-destructive behavior. The purpose of our empirical research was to determine the main characteristics of basic conceptual formations in the structure of a world image—that is, attitudes, intentions, motives, and values— that serve as predictors of disadaptation in modern teenagers. The teenagers in the study were born in different generations with a ten-year interval (1990–1991 and 2000–2001. Our empirical research of the semantic world-image structures that serve as bases for the self-destructive behavior of modern teenagers consisted of two phases. The first phase provided a comparative analysis of the relationships, value preferences, and basic conceptual intentions that raise the possibility of disadaptation and self-destructive behavior among teenagers. In order to perform this analysis, we analyzed data from the Character-Pathological Diagnostic Poll (PDP of A. E. Lichko. During the second phase, a comparative analysis was carried out of the basic semantic components of teenagers’ images of the world and self-destructive and normative behavior. The main conceptual world-image structures were defined with the help of projective methods: the Thematic Apperception

Structure and phase formation behavior and dielectric and magnetic properties of lead iron tantalate-lead zirconate titanate multiferroic ceramics

International Nuclear Information System (INIS)

Wongmaneerung, R.; Tipakontitikul, R.; Jantaratana, P.; Bootchanont, A.; Jutimoosik, J.; Yimnirun, R.; Ananta, S.

2016-01-01

Highlights: • The multiferroic ceramics consisted of PFT and PZT. • Crystal structure changed from cubic to mixedcubic and tetragonal with increasing PZT content. • Dielectric showed the samples underwent a typical relaxor ferroelectric behavior. • Magnetic properties showed very interesting behavior with square saturated magnetic hysteresis loops. - Abstract: Multiferroic (1 − x)Pb(Fe_0_._5Ta_0_._5)O_3–xPb(Zr_0_._5_3Ti_0_._4_7)O_3 (or PFT–PZT) ceramics were synthesized by solid-state reaction method. The crystal structure and phase formation of the ceramics were examined by X-ray diffraction (XRD). The local structure surrounding Fe and Ti absorbing atoms was investigated by synchrotron X-ray Absorption Near-Edge Structure (XANES) measurement. Dielectric properties were studied as a function of frequency and temperature using a LCR meter. A vibrating sample magnetometer (VSM) was used to determine the magnetic hysteresis loops. XRD study indicated that the crystal structure of the sample changed from pure cubic to mixed cubic and tetragonal with increasing PZT content. XANES measurements showed that the local structure surrounding Fe and Ti ions was similar. Dielectric study showed that the samples underwent a typical relaxor ferroelectric behavior while the magnetic properties showed very interesting behavior with square saturated magnetic hysteresis loops.

Relationship between Leadership Behaviors of High School Principals and Teacher Retention in Texas

Science.gov (United States)

Aiken, Debra L.

2010-01-01

The study investigated the relationship between leadership behaviors of high school principals and teacher retention in Texas. A total of 88 Texas high school principals participated in the survey. Leadership behaviors were measured using the Culturally Adapted Leadership for Inspired Business Excellence and Results (CALIBER) Leadership Assessment…

Factor Structure of the Children's Behavior Questionnaire in Children with Williams Syndrome

Science.gov (United States)

Leyfer, Ovsanna; John, Angela E.; Woodruff-Borden, Janet; Mervis, Carolyn B.

2012-01-01

To examine the factor structure of temperament in 5-10-year-olds with Williams syndrome, an exploratory factor analysis was conducted on the responses of parents of 192 children on the children's behavior questionnaire. Four factors were identified. Two corresponded to factors reported for typically developing children: effortful control and…

INSTRUMENTS OF HIGH RISK SEXUAL BEHAVIOR ASSESSMENT: A SYSTEMATIC REVIEW.

Science.gov (United States)

Mirzaei, Mojtaba; Ahmadi, Khodabakhsh; Saadat, Seyed-Hassan; Ramezani, Mohammad Arash

2016-02-01

Sexual behavior is a complex activity affecting all aspects of human's life. Risky sexual behaviors impose negative outcomes on family, relationships and health. Unsafe sex is the second most leading cause of disability adjusted life years worldwide. Valid and reliable tools for assessment of risky sexual behaviors are necessary for implementing preventive measures. we searched Medline and the Cochrane Library of Systematic Reviews, with the keywords of "risky sexual behavior assessment", "sexual risk assessment", "high risk sexual behavior", "sexual risk taking". By reviewing references of the articles, some complementary studies were added. Assessment can be performed by questionnaire or non-questionnaire instruments. Questionnaires vary depending on their target population, evaluation of risky sexual behavior as a whole or focusing on an associated risk factor. In order to avoid usual biases in self reports, objective biomarker assessment of unprotected sex are employed. These markers include prostate specific antigen, chromosome Y DNA and Seminogelin. Risky sexual behavior can be assessed by various subjective and objective methods. While self-reports are more feasible, objective methods offer a higher degree of reliability. Further studies for finding more feasible methods of using biomarkers are recommended.

Behavioral in-effectiveness of high frequency electromagnetic field in mice.

Science.gov (United States)

Salunke, Balwant P; Umathe, Sudhir N; Chavan, Jagatpalsingh G

2015-03-01

The present investigation was carried out with an objective to study the influence of high frequency electromagnetic field (HF-EMF) on anxiety, obsessive compulsive disorder (OCD) and depression-like behavior. For exposure to HF-EMF, non-magnetic material was used to fabricate the housing. Mice were exposed to HF-EMF (2.45GHz), 60min/day for 7 or 30 or 60 or 90 or 120days. The exposure was carried out by switching-on inbuilt class-I BLUETOOTH device that operates on 2.45GHz frequency in file transfer mode at a peak density of 100mW. Mice were subjected to the assessment of anxiety, OCD and depression-like behavior for 7 or 30 or 60 or 90 or 120days of exposure. The anxiety-like behavior was assessed by elevated plus maze, open field test and social interaction test. OCD-like behavior was assessed by marble burying behavior, whereas depression-like behavior was assessed by forced swim test and tail suspension test. The present experiment demonstrates that up to 120days of exposure to HF-EMF does not produce anxiety, OCD and depression-like behavior in mice. Copyright © 2014 Elsevier Inc. All rights reserved.

The structure of filled skutterudites and the local vibration behavior of the filling atom

Energy Technology Data Exchange (ETDEWEB)

Zhou, Xiaojuan [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dongguan Institute of Neutron Science, Dongguan 523808 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zong, Peng-an [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Chen, Xihong [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Tao, Juzhou, E-mail: taoj@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dongguan Institute of Neutron Science, Dongguan 523808 (China); Lin, He, E-mail: linhe@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201204 (China)

2017-02-15

Both of atomic pair distribution function (PDF) and extended x-ray absorption fine structure (EXAFS) experiments have been carried out on unfilled and Yb-filled skutterudites Yb{sub x}Co{sub 4}Sb{sub 12} (x=0, 0.15, 0.2 and 0.25) samples. The structure refinements on PDF data confirm the large amplitude vibration of Yb atom and the dependence of Yb vibration amplitude on the filling content. Temperature dependent EXAFS experiment on filled skutterudites have been carried out at Yb L{sub Ⅲ}-edge in order to explore the local vibration behavior of filled atom. EXAFS experiments show that the Einstein temperature of the filled atom is very low (70.9 K) which agrees with the rattling behavior.

On the origin of grasshopper oviposition behavior: structural homology in pregenital and genital motor systems.

Science.gov (United States)

Thompson, Karen J; Jones, Alaine D; Miller, Sandra A

2014-01-01

In female grasshoppers, oviposition is a highly specialized behavior involving a rhythm-generating neural circuit, the oviposition central pattern generator, unusual abdominal appendages, and dedicated muscles. This study of Schistocerca americana (Drury) grasshoppers was undertaken to determine whether the simpler pregenital abdominal segments, which do not contain ovipositor appendages, share common features with the genital segment, suggesting a roadmap for the genesis of oviposition behavior. Our study revealed that although 5 of the standard pregenital body wall muscles were missing in the female genital segment, homologous lateral nerves were, indeed, present and served 4 ovipositor muscles. Retrograde labeling of the corresponding pregenital nerve branches in male and female grasshoppers revealed motor neurons, dorsal unpaired median neurons, and common inhibitor neurons which appear to be structural homologues of those filled from ovipositor muscles. Some pregenital motor neurons displayed pronounced contralateral neurites; in contrast, some ovipositor motor neurons were exclusively ipsilateral. Strong evidence of structural homology was also obtained for pregenital and ovipositor skeletal muscles supplied by the identified neurons and of the pregenital and ovipositor skeletons. For example, transient embryonic segmental appendages were maintained in the female genital segments, giving rise to ovipositor valves, but were lost in pregenital abdominal segments. Significant proportional differences in sternal apodemes and plates were observed, which partially obscure the similarities between the pregenital and genital skeletons. Other changes in reorganization included genital muscles that displayed adult hypertrophy, 1 genital muscle that appeared to represent 2 fused pregenital muscles, and the insertion points of 2 ovipositor muscles that appeared to have been relocated. Together, the comparisons support the idea that the oviposition behavior of genital

High Behavioral Approach System (BAS) sensitivity, reward responsiveness, and goal-striving predict first onset of bipolar spectrum disorders: a prospective behavioral high-risk design.

Science.gov (United States)

Alloy, Lauren B; Bender, Rachel E; Whitehouse, Wayne G; Wagner, Clara A; Liu, Richard T; Grant, David A; Jager-Hyman, Shari; Molz, Ashleigh; Choi, James Y; Harmon-Jones, Eddie; Abramson, Lyn Y

2012-05-01

A prospective, behavioral high-risk design provided a theoretically guided examination of vulnerability to first onset of bipolar spectrum disorder based on the Behavioral Approach System (BAS) model. Adolescents (ages 14-19) at an "age of risk" for bipolar disorder onset were screened on BAS sensitivity by interviewers blind to current symptoms, lifetime history, and family history of psychopathology. Participants were selected with high versus moderate levels of BAS sensitivity and administered a lifetime diagnostic interview. Those with a bipolar spectrum disorder, psychosis, or hypomanic episode with onset prior to the BAS sensitivity assessment were excluded. High BAS (n = 171) and moderate BAS (n = 119) sensitivity participants in the final sample completed baseline measures of symptoms, goal-setting, and reward responsiveness and were followed prospectively with semistructured diagnostic interviews every 6 months. Consistent with the vulnerability hypothesis of the BAS model of bipolar disorder, high BAS participants had a greater likelihood, and shorter time to onset, of bipolar spectrum disorder than moderate BAS participants across an average of 12.8 months of follow-up (12.9% vs. 4.2%), controlling for baseline depressive and hypomanic symptoms, and family history of bipolar disorder. High reward responsiveness on a behavioral task and ambitious goal-striving for popular fame and financial success (but not impulsivity) also predicted first onset of bipolar spectrum disorder controlling for the covariates and BAS risk group, and ambitious goal-striving partially mediated the BAS risk group effect. We discuss implications of the findings for the BAS model of bipolar disorder and early intervention efforts.

Behavior of technetium in alkaline solution: Identification of non-pertechnetate species in high-level nuclear waste tanks at the Hanford reservation

International Nuclear Information System (INIS)

Lukens, Wayne W. Jr.; Shuh, David K.; Schroeder, Norman C.; Ashley, Kenneth R.

2003-01-01

Technetium is a long-lived (99Tc: 213,000 year half-life) fission product found in nuclear waste and is one of the important isotopes of environmental concern. The known chemistry of technetium suggests that it should be found as pertechnetate, TcO4-, in the extremely basic environment of the nuclear waste tanks at the Hanford site. However, other chemical forms of technetium are present in significant amounts in certain tanks, and these non-pertechnetate species complicate the treatment of the waste. The only spectroscopic characterization of these non-pertechnetate species is a series of X-ray absorption near edge structure (XANES) spectra of actual tank waste. To better understand the behavior of technetium under these conditions, we have investigated the reduction of pertechnetate in highly alkaline solution in the presence of compounds found in high-level waste. These results and the X-ray absorption fine structure (XAFS) spectra of these species are compared to the chemical behavior and XANES spectra of the actual non-pertechnetate species. The identity of the nonpertechnetate species is surprising

Effects of growth rate on structural property and adatom migration behaviors for growth of GaInNAs/GaAs (001) by molecular beam epitaxy

Science.gov (United States)

Li, Jingling; Gao, Peng; Zhang, Shuguang; Wen, Lei; Gao, Fangliang; Li, Guoqiang

2018-03-01

We have investigated the structural properties and the growth mode of GaInNAs films prepared at different growth rates (Rg) by molecular beam epitaxy. The crystalline structure is studied by high resolution X-ray diffraction, and the evolution of GaInNAs film surface morphologies is studied by atomic force microscopy. It is found that both the crystallinity and the surface roughness are improved by increasing Rg, and the change in the growth mode is attributed to the adatom migration behaviors particularly for In atoms, which is verified by elemental analysis. In addition, we have presented some theoretical calculation results related to the N adsorption energy to show the unique N migration behavior, which is instructive to interpret the growth mechanism of GaInNAs films.

Numerical simulation of the fatigue behavior of additive manufactured titanium porous lattice structures

Energy Technology Data Exchange (ETDEWEB)

Zargarian, A.; Esfahanian, M. [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Kadkhodapour, J., E-mail: j.kad@srttu.edu [Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran (Iran, Islamic Republic of); Institute for Materials Testing, Materials Science and Strength of Materials (IMWF), University of Stuttgart, Stuttgart (Germany); Ziaei-Rad, S. [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

2016-03-01

In this paper, the effects of cell geometry and relative density on the high-cycle fatigue behavior of Titanium scaffolds produced by selective laser melting and electron beam melting techniques were numerically investigated by finite element analysis. The regular titanium lattice samples with three different unit cell geometries, namely, diamond, rhombic dodecahedron and truncated cuboctahedron, and the relative density range of 0.1–0.3 were analyzed under uniaxial cyclic compressive loading. A failure event based algorithm was employed to simulate fatigue failure in the cellular material. Stress-life approach was used to model fatigue failure of both bulk (struts) and cellular material. The predicted fatigue life and the damage pattern of all three structures were found to be in good agreement with the experimental fatigue investigations published in the literature. The results also showed that the relationship between fatigue strength and cycles to failure obeyed the power law. The coefficient of power function was shown to depend on relative density, geometry and fatigue properties of the bulk material while the exponent was only dependent on the fatigue behavior of the bulk material. The results also indicated the failure surface at an angle of 45° to the loading direction. - Highlights: • Numerical simulation was used to predict fatigue behavior of titanium scaffolds. • Good agreement between numerical and experimental results • S–N curves obeyed the power law. • Fatigue strength of scaffolds was proportional to their Young's modulus. • Failure surface of scaffolds was inclined at an angle of 45° to loading.

Creep Behavior of High-Strength Concrete Subjected to Elevated Temperatures.

Science.gov (United States)

Yoon, Minho; Kim, Gyuyong; Kim, Youngsun; Lee, Taegyu; Choe, Gyeongcheol; Hwang, Euichul; Nam, Jeongsoo

2017-07-11

Strain is generated in concrete subjected to elevated temperatures owing to the influence of factors such as thermal expansion and design load. Such strains resulting from elevated temperatures and load can significantly influence the stability of a structure during and after a fire. In addition, the lower the water-to-binder (W-B) ratio and the smaller the quantity of aggregates in high-strength concrete, the more likely it is for unstable strain to occur. Hence, in this study, the compressive strength, elastic modulus, and creep behavior were evaluated at target temperatures of 100, 200, 300, 500, and 800 °C for high-strength concretes with W-B ratios of 30%, 26%, and 23%. The loading conditions were set as non-loading and 0.33f cu . It was found that as the compressive strength of the concrete increased, the mechanical characteristics deteriorated and transient creep increased. Furthermore, when the point at which creep strain occurred at elevated temperatures after the occurrence of transient creep was considered, greater shrinkage strain occurred as the compressive strength of the concrete increased. At a heating temperature of 800 °C, the 80 and 100 MPa test specimens showed creep failure within a shrinkage strain range similar to the strain at the maximum load.

Creep Behavior of High-Strength Concrete Subjected to Elevated Temperatures

Directory of Open Access Journals (Sweden)

Minho Yoon

2017-07-01

Full Text Available Strain is generated in concrete subjected to elevated temperatures owing to the influence of factors such as thermal expansion and design load. Such strains resulting from elevated temperatures and load can significantly influence the stability of a structure during and after a fire. In addition, the lower the water-to-binder (W–B ratio and the smaller the quantity of aggregates in high-strength concrete, the more likely it is for unstable strain to occur. Hence, in this study, the compressive strength, elastic modulus, and creep behavior were evaluated at target temperatures of 100, 200, 300, 500, and 800 °C for high-strength concretes with W–B ratios of 30%, 26%, and 23%. The loading conditions were set as non-loading and 0.33fcu. It was found that as the compressive strength of the concrete increased, the mechanical characteristics deteriorated and transient creep increased. Furthermore, when the point at which creep strain occurred at elevated temperatures after the occurrence of transient creep was considered, greater shrinkage strain occurred as the compressive strength of the concrete increased. At a heating temperature of 800 °C, the 80 and 100 MPa test specimens showed creep failure within a shrinkage strain range similar to the strain at the maximum load.

High-resolution 2-D Bragg diffraction reveal heterogeneous domain transformation behavior in a bulk relaxor ferroelectric

Energy Technology Data Exchange (ETDEWEB)

Pramanick, Abhijit, E-mail: apramani@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Kowloon (Hong Kong); Stoica, Alexandru D.; An, Ke [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2016-08-29

In-situ measurement of fine-structure of neutron Bragg diffraction peaks from a relaxor single-crystal using a time-of-flight instrument reveals highly heterogeneous mesoscale domain transformation behavior under applied electric fields. It is observed that only ∼25% of domains undergo reorientation or phase transition contributing to large average strains, while at least 40% remain invariant and exhibit microstrains. Such insights could be central for designing new relaxor materials with better performance and longevity. The current experimental technique can also be applied to resolve complex mesoscale phenomena in other functional materials.

Numerical simulation of the fatigue behavior of additive manufactured titanium porous lattice structures.

Science.gov (United States)

Zargarian, A; Esfahanian, M; Kadkhodapour, J; Ziaei-Rad, S

2016-03-01

In this paper, the effects of cell geometry and relative density on the high-cycle fatigue behavior of Titanium scaffolds produced by selective laser melting and electron beam melting techniques were numerically investigated by finite element analysis. The regular titanium lattice samples with three different unit cell geometries, namely, diamond, rhombic dodecahedron and truncated cuboctahedron, and the relative density range of 0.1-0.3 were analyzed under uniaxial cyclic compressive loading. A failure event based algorithm was employed to simulate fatigue failure in the cellular material. Stress-life approach was used to model fatigue failure of both bulk (struts) and cellular material. The predicted fatigue life and the damage pattern of all three structures were found to be in good agreement with the experimental fatigue investigations published in the literature. The results also showed that the relationship between fatigue strength and cycles to failure obeyed the power law. The coefficient of power function was shown to depend on relative density, geometry and fatigue properties of the bulk material while the exponent was only dependent on the fatigue behavior of the bulk material. The results also indicated the failure surface at an angle of 45° to the loading direction. Copyright © 2015 Elsevier B.V. All rights reserved.

Effectiveness of Methadone in Reduction of High Risk Behaviors in Clients of MMT Center

Directory of Open Access Journals (Sweden)

F Ehsani

2010-09-01

Full Text Available Introduction: Addiction as a social, health problem with its specific complications threatens societies. High risk behaviors such as violence, self mutilation, tattooing, shared injections and unprotected sex behaviors are some of the problems in addicts that need to be treated. One of these treatments is methadone therapy. The purpose of this study was to evaluate effectiveness of methadone in prevention or reduction of high risk behaviors in clients of a MMT center of Shaheed Sadoughi University of medical sciences of Yazd. Methods: This study was done on 93 clients of a MMT center.Questionnaire for this study included items from MAP and questions about some other risky behaviors. This questionnaire was completed at onset of treatment and 6 months after. Data was analyzed with SPSS software program Results: 89.2% of participants were married and 10.8% were single. 63.5% of them were in the20-40 years age group. Most commonly abused substances were heroin and opium. Before onset of treatment, 37.6% of participants had history of imprisonment, 35.5% had shared injections, 32.3%had had unprotected sex, 22.6%had tattooing and 5.4%had mutilated their own selves. Only 36.6% didn’t have any high risk behavior. These behaviors were more common in heroin users and in the20-40 years age group. After onset of treatment and during 6 month of MMT, 86% of clients didn’t have any risky behavior. Only 14%of them continued to have unsafe sex behaviors Conclusion: Addiction can cause high risk behaviors. Data in this paper suggests that young age, heroin use, low education level and no or inadequate information about addictive substances and their consequences are effective and important factors that cause high risk behaviors. Treatment of addicts with methadone maintenance therapy plays an important role in reduction of risky behaviors. Development of appropriate and more MMT centers are recommended.

Characterization, optical properties and laser ablation behavior of epoxy resin coatings reinforced with high reflectivity ceramic particles

Science.gov (United States)

Li, Wenzhi; Kong, Jing; Wu, Taotao; Gao, Lihong; Ma, Zhuang; Liu, Yanbo; Wang, Fuchi; Wei, Chenghua; Wang, Lijun

2018-04-01

Thermal damage induced by high power energy, especially high power laser, significantly affects the lifetime and performance of equipment. High-reflectance coating/film has attracted considerable attention due to its good performance in the damage protection. Preparing a high-reflectance coating with high reaction endothermal enthalpy will effectively consume a large amount of incident energy and in turn protect the substrate from thermal damage. In this study, a low temperature process was used to prepare coatings onto substrate with complex shape and avoid thermal effect during molding. An advanced high reflection ceramic powder, La1‑xSrxTiO3+δ , was added in the epoxy adhesive matrix to improve the reflectivity of coating. The optical properties and laser ablation behaviors of coatings with different ceramic additive ratio of La1‑xSrxTiO3+δ and modified epoxy-La1‑xSrxTiO3+δ with ammonium polyphosphate coatings were investigated, respectively. We found that the reflectivity of coatings is extremely high due to mixed high-reflection La1‑xSrxTiO3+δ particles, up to 96% at 1070 nm, which can significantly improve the laser resistance. In addition, the ammonium polyphosphate modifies the residual carbon structure of epoxy resin from discontinuous fine particles structure to continuous and porous structure, which greatly enhances the thermal-insulation property of coating. Furthermore, the laser ablation threshold is improved obviously, which is from 800 W cm‑2 to 1000 W cm‑2.

Plasma exposure behavior of re-deposited tungsten on structural materials of fusion reactors

Energy Technology Data Exchange (ETDEWEB)

Xu, Yu-Ping; Wang, Jing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei 230031 (China); Zhou, Hai-Shan, E-mail: haishanzhou@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Zeng-De [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Li, Xiao-Chun; Lu, Tao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Hao-Dong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei 230031 (China); Ding, Fang; Mao, Hong-Min; Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Lin, Chen-Guang [General Research Institute for Nonferrous Metals, Beijing 100088 (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei 230031 (China); Hefei Center for Physical Science and Technology, Hefei 230031 (China); Hefei Science Center of Chinese Academy of Science, Hefei 230027 (China)

2017-05-15

To evaluate the effects of re-deposited tungsten (W) on the surface modification and hydrogen isotope retention behavior of fusion structural materials, the plasma exposure behavior of re-deposited W samples prepared by magnetron sputtering on the F82H steel, the V-5Cr-5Ti alloy as well as bare substrate samples was investigated. All the samples were exposed to 367 shots of deuterium plasmas in the 2015 spring EAST campaign. After the plasma exposure, large area of W layer was exfoliated, while big blisters were found at the interface between the remaining W layer and the substrate materials. The deuterium retention behavior of the samples with re-deposited W layer was characterized by thermal desorption spectroscopy and compared with the bare substrate samples.

Non-ohmic transport behavior in ultra-thin gold films

International Nuclear Information System (INIS)

Alkhatib, A.; Souier, T.; Chiesa, M.

2011-01-01

Highlights: → C-AFM study on ultra-thin gold films. → Connection between ultra-thin film morphology and lateral electrical transport. → Transition between ohmic and non-ohmic behavior. → Electrical transition correlation to the film structure continuity. → Direct and indirect tunneling regimes related to discontinuous structures. - Abstract: Structure and local lateral electrical properties of Au films of thicknesses ranging from 10 to 140 nm are studied using conductive atomic force microscopy. Comparison of current maps taken at different thicknesses reveals surprising highly resistive regions (10 10 -10 11 Ω), the density of which increases strongly at lower thickness. The high resistivity is shown to be directly related to discontinuities in the metal sheet. Local I-V curves are acquired to show the nature of electrical behavior relative to thickness. Results show that in Au films of higher thickness the electrical behavior is ohmic, while it is non-ohmic in highly discontinuous films of lower thickness, with the transition happening between 34 and 39 nm. The non-ohmic behavior is explained with tunneling occurring between separated Au islands. The results explain the abrupt increase of electrical resistivity at lower thin film thicknesses.

Pine Plantations and Invasion Alter Fuel Structure and Potential Fire Behavior in a Patagonian Forest-Steppe Ecotone

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Juan Paritsis

2018-03-01

Full Text Available Planted and invading non-native plant species can alter fire regimes through changes in fuel loads and in the structure and continuity of fuels, potentially modifying the flammability of native plant communities. Such changes are not easily predicted and deserve system-specific studies. In several regions of the southern hemisphere, exotic pines have been extensively planted in native treeless areas for forestry purposes and have subsequently invaded the native environments. However, studies evaluating alterations in flammability caused by pines in Patagonia are scarce. In the forest-steppe ecotone of northwestern Patagonia, we evaluated fine fuels structure and simulated fire behavior in the native shrubby steppe, pine plantations, pine invasions, and mechanically removed invasions to establish the relative ecological vulnerability of these forestry and invasion scenarios to fire. We found that pine plantations and their subsequent invasion in the Patagonian shrubby steppe produced sharp changes in fine fuel amount and its vertical and horizontal continuity. These changes in fuel properties have the potential to affect fire behavior, increasing fire intensity by almost 30 times. Pruning of basal branches in plantations may substantially reduce fire hazard by lowering the probability of fire crowning, and mechanical removal of invasion seems effective in restoring original fuel structure in the native community. The current expansion of pine plantations and subsequent invasions acting synergistically with climate warming and increased human ignitions warrant a highly vulnerable landscape in the near future for northwestern Patagonia if no management actions are undertaken.

The effect of differentiated margin on futures market investors' behavior and structure An experimental research

Institute of Scientific and Technical Information of China (English)

Jin-hui Luo; Di-fang Wan; Yang Yang; Guang Yang

2011-01-01

Purpose-The purpose of this paper is to empirically analyze the role of differentiated margin system in leading investors' investing behavior and then optimize investor structure in futures markets.Design/methodology/approach-Using economic experimental research method,this paper designs and conducts a futures market experiment according to experimental research's basic norms,thus acquiring needed and credible empirical data.Findings-By analyzing the experimental data,it is found that compared with situations in futures markets that implement uniform margin system,investors' (especially speculators') futures open position and the ratio of their open position and futures turnover are both significantly higher,in futures markets that implement differentiated margin system.On the other hand,differentiated margin system has no effects on hedgers' futures turnover,but significantly reduces speculators' futures turnover.Research limitations/implications-The findings suggest that compared with uniform margin system,differentiated margin system is beneficial to effectively restrict both speculators' and hedgers' speculating behavior and lead hedgers' market participation.Practical implications-In order to resolve the problem of unreasonable investor structure in China's futures market,i.e.lack of hedgers and over-speculating China's futures market's regulators should reform the margin system and adopt differentiated margin system to lead investors' rational behavior and optimize investor structure.Originality/value-This paper empirically analyzes and verifies,for the first time,the roles of differentiated margin system in affecting investors' investing behavior.The futures market experiment designed and used in this study is a pioneering and exploratory experiment.

Longitudinal connectome-based predictive modeling for REM sleep behavior disorder from structural brain connectivity

Science.gov (United States)

Giancardo, Luca; Ellmore, Timothy M.; Suescun, Jessika; Ocasio, Laura; Kamali, Arash; Riascos-Castaneda, Roy; Schiess, Mya C.

2018-02-01

Methods to identify neuroplasticity patterns in human brains are of the utmost importance in understanding and potentially treating neurodegenerative diseases. Parkinson disease (PD) research will greatly benefit and advance from the discovery of biomarkers to quantify brain changes in the early stages of the disease, a prodromal period when subjects show no obvious clinical symptoms. Diffusion tensor imaging (DTI) allows for an in-vivo estimation of the structural connectome inside the brain and may serve to quantify the degenerative process before the appearance of clinical symptoms. In this work, we introduce a novel strategy to compute longitudinal structural connectomes in the context of a whole-brain data-driven pipeline. In these initial tests, we show that our predictive models are able to distinguish controls from asymptomatic subjects at high risk of developing PD (REM sleep behavior disorder, RBD) with an area under the receiving operating characteristic curve of 0.90 (pParkinson's Progression Markers Initiative. By analyzing the brain connections most relevant for the predictive ability of the best performing model, we find connections that are biologically relevant to the disease.

Co-relationship between sexual dysfunction and high-risk sexual behavior in patients receiving buprenorphine and naltrexone maintenance therapy for opioid dependence

Directory of Open Access Journals (Sweden)

Santosh Ramdurg

2015-01-01

Full Text Available Introduction: People suffering from substance dependence suffer from various sexual dysfunctions and are at risk for indulging in various high-risk sexual behaviors and thus are vulnerable to acquire various infections such as HIV/AIDS and other sexually transmitted infections. AIM: The aim of the study was to evaluate the correlation between sexual dysfunction and high-risk sexual behavior in opioid-dependent men receiving buprenorphine and naltrexone maintenance therapy. Materials and Methods: Semi-structured questionnaire, brief male sexual functioning inventory and HIV-risk taking behavior scale was administered to a sample of 60 sexually active men, receiving buprenorphine (n = 30 and naltrexone (n = 30 maintenance therapy for opioid dependence. Results: The main outcomes are correlation between severity of sexual dysfunction and HIV-risk taking behavior. The study results showed 83% of the men on buprenorphine and 90% on naltrexone reported at least one of the sexual dysfunction symptoms. There was a negative correlation between sexual dysfunction and HIV-risk taking behavior that suggest severe the dysfunction, higher the risk taking behavior. Significant correlation was present with overall sexual dysfunction and HIV-risk taking behavior (P = 0.028 and in naltrexone receiving group premature ejaculation versus HIV-risk taking behavior however, (P = 0.022, P < 0.05 there were no significant differences among both the groups except above findings. Conclusion: Conclusion was treatment is associated with sexual dysfunctions and HIV-risk taking behavior, which has clinical implication. Future research should explore this further using biochemical analyses.

Protective role of Arapaima gigas fish scales: structure and mechanical behavior.

Science.gov (United States)

Yang, Wen; Sherman, Vincent R; Gludovatz, Bernd; Mackey, Mason; Zimmermann, Elizabeth A; Chang, Edwin H; Schaible, Eric; Qin, Zhao; Buehler, Markus J; Ritchie, Robert O; Meyers, Marc A

2014-08-01

The scales of the arapaima (Arapaima gigas), one of the largest freshwater fish in the world, can serve as inspiration for the design of flexible dermal armor. Each scale is composed of two layers: a laminate composite of parallel collagen fibrils and a hard, highly mineralized surface layer. We review the structure of the arapaima scales and examine the functions of the different layers, focusing on the mechanical behavior, including tension and penetration of the scales, with and without the highly mineralized outer layer. We show that the fracture of the mineral and the stretching, rotation and delamination of collagen fibrils dissipate a significant amount of energy prior to catastrophic failure, providing high toughness and resistance to penetration by predator teeth. We show that the arapaima's scale has evolved to minimize damage from penetration by predator teeth through a Bouligand-like arrangement of successive layers, each consisting of parallel collagen fibrils with different orientations. This inhibits crack propagation and restricts damage to an area adjoining the penetration. The flexibility of the lamellae is instrumental to the redistribution of the compressive stresses in the underlying tissue, decreasing the severity of the concentrated load produced by the action of a tooth. The experimental results, combined with small-angle X-ray scattering characterization and molecular dynamics simulations, provide a complete picture of the mechanisms of deformation, delamination and rotation of the lamellae during tensile extension of the scale. Copyright © 2014 Acta Materialia Inc. All rights reserved.

Oscillatory behaviors and hierarchical assembly of contractile structures in intercalating cells

International Nuclear Information System (INIS)

Fernandez-Gonzalez, Rodrigo; Zallen, Jennifer A

2011-01-01

Fluctuations in the size of the apical cell surface have been associated with apical constriction and tissue invagination. However, it is currently not known if apical oscillatory behaviors are a unique property of constricting cells or if they constitute a universal feature of the force balance between cells in multicellular tissues. Here, we set out to determine whether oscillatory cell behaviors occur in parallel with cell intercalation during the morphogenetic process of axis elongation in the Drosophila embryo. We applied multi-color, time-lapse imaging of living embryos and SIESTA, an integrated tool for automated and semi-automated cell segmentation, tracking, and analysis of image sequences. Using SIESTA, we identified cycles of contraction and expansion of the apical surface in intercalating cells and characterized them at the molecular, cellular, and tissue scales. We demonstrate that apical oscillations are anisotropic, and this anisotropy depends on the presence of intact cell–cell junctions and spatial cues provided by the anterior–posterior patterning system. Oscillatory cell behaviors during axis elongation are associated with the hierarchical assembly and disassembly of contractile actomyosin structures at the medial cortex of the cell, with actin localization preceding myosin II and with the localization of both proteins preceding changes in cell shape. We discuss models to explain how the architecture of cytoskeletal networks regulates their contractile behavior and the mechanisms that give rise to oscillatory cell behaviors in intercalating cells

High-Temperature Corrosion Behavior of Alloy 617 in Helium Environment of Very High Temperature Gas Reactor

International Nuclear Information System (INIS)

Lee, Gyeong-Geun; Jung, Sujin; Kim, Daejong; Jeong, Yong-Whan; Kim, Dong-Jin

2012-01-01

Alloy 617 is a Ni-base superalloy and a candidate material for the intermediate heat exchanger (IHX) of a very high temperature gas reactor (VHTR) which is one of the next generation nuclear reactors under development. The high operating temperature of VHTR enables various applications such as mass production of hydrogen with high energy efficiency. Alloy 617 has good creep resistance and phase stability at high temperatures in an air environment. However, it was reported that the mechanical properties decreased at a high temperature in an impure helium environment. In this study, high-temperature corrosion tests were carried out at 850°C-950°C in a helium environment containing the impurity gases H_2, CO, and CH_4, in order to examine the corrosion behavior of Alloy 617. Until 250 h, Alloy 617 specimens showed a parabolic oxidation behavior at all temperatures. The activation energy for oxidation in helium environment was 154 kJ/mol. The SEM and EDS results elucidated a Cr-rich surface oxide layer, Al-rich internal oxides and depletion of grain boundary carbides. The thickness and depths of degraded layers also showed a parabolic relationship with time. A normal grain growth was observed in the Cr-rich surface oxide layer. When corrosion tests were conducted in a pure helium environment, the oxidation was suppressed drastically. It was elucidated that minor impurity gases in the helium would have detrimental effects on the high temperature corrosion behavior of Alloy 617 for the VHTR application.

Family Influences on Dropout Behavior in One California High School.

Science.gov (United States)

Rumberger, Russell W.; And Others

1990-01-01

Investigated how family processes influence high school student dropout behavior. Used a sample of 114 dropouts from 1 California high school, 48 of whom were matched to similarly profiled continuing students. Identified factors that explain students' dropout decisions: permissive parenting, negative parental reactions to grades, excessive…

Unifying logarithmic and factorial behavior in high-energy scattering

International Nuclear Information System (INIS)

Cornwall, J.M.; Morris, D.A.

1995-01-01

The elegant instanton calculus of Lipatov and others used to find factorially divergent behavior (g N N exclamation point) for N g much-gt 1 in gφ 4 perturbation theory is strictly only applicable when all external momenta vanish; a description of high-energy 2→N scattering with N massive particles is beyond the scope of such techniques. On the other hand, a standard multiperipheral treatment of scattering with its emphasis on leading logarithms gives a reasonable picture of high-energy behavior but does not result in factorial divergences. Using a straightforward graphical analysis we present a unified picture of both these phenomena as they occur in the two-particle total cross section of gφ 4 theory. We do not attempt to tame the unitarity violations associated with either multiperipheralism or the Lipatov technique at strong coupling

Fault structure, frictional properties and mixed-mode fault slip behavior

NARCIS (Netherlands)

Collettini, C.; Niemeijer, A.; Viti, C.; Smith, S.A.F.; Marone, C.

2011-01-01

Recent high-resolution GPS and seismological data reveal that tectonic faults exhibit complex, multi-modeslipbehavior including earthquakes, creep events, slow and silent earthquakes, low-frequency events and earthquake afterslip. The physical processes responsible for this range of behavior and the

Movement Behavior of High-Heeled Walking

DEFF Research Database (Denmark)

Alkjær, Tine; Raffalt, Peter Christian; Petersen, Nicolas Caesar

2012-01-01

The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ask how the nervous system controls the ankle joint in this situation? We investigated the movement...... behavior of high-heeled and barefooted walking in eleven female subjects. The movement variability was quantified by calculation of approximate entropy (ApEn) in the ankle joint angle and the standard deviation (SD) of the stride time intervals. Electromyography (EMG) of the soleus (SO) and tibialis...... anterior (TA) muscles and the soleus Hoffmann (H-) reflex were measured at 4.0 km/h on a motor driven treadmill to reveal the underlying motor strategies in each walking condition. The ApEn of the ankle joint angle was significantly higher (p...

Structural Alterations in the Corpus Callosum Are Associated with Suicidal Behavior in Women with Borderline Personality Disorder

Directory of Open Access Journals (Sweden)

Alexander Lischke

2017-04-01

Full Text Available Structural alterations in the corpus callosum (CC, the major white matter tract connecting functionally related brain regions in the two hemispheres, have been shown to be associated with emotional instability, impulsivity and suicidality in various mental disorders. To explore whether structural alterations of the CC would be similarly associated with emotional instability, impulsivity and suicidality in borderline personality disorder (BPD, we used diffusion tensor imaging (DTI to assess the structural integrity of the CC in 21 BPD and 20 healthy control (HC participants. Our hypothesis-driven analyses revealed a positive correlation between BPD participants’ suicidal behavior and fractional anisotropy (FA in the splenium and genu of the CC and a negative correlation between BPD participants’ suicidal behavior and mean diffusivity (MD in the splenium of CC. Our exploratory analyses suggested that suicidal BPD participants showed less FA and more MD in these regions than HC participants but that non-suicidal BPD participants showed similar FA and MD in these regions as HC participants. Taken together, our findings suggest an association between BPD participants’ suicidal behavior and structural alterations in regions of the CC that are connected with brain regions implicated in emotion regulation and impulse control. Structural alterations of the CC may, thus, account for deficits in emotion regulation and impulse control that lead to suicidal behavior in BPD. However, these findings should be considered as preliminary until replicated and extended in future studies that comprise larger samples of suicidal and non-suicidal BPD participants.

Structure-retention and mobile phase-retention relationships for reversed-phase high-performance liquid chromatography of several hydroxythioxanthone derivatives in binary acetonitrile-water mixtures

International Nuclear Information System (INIS)

Amiri, Ali Asghar; Hemmateenejad, Bahram; Safavi, Afsaneh; Sharghi, Hashem; Beni, Ali Reza Salimi; Shamsipur, Mojtaba

2007-01-01

The reversed-phase high-performance liquid chromatographic (RP-HPLC) behavior of some newly synthesized hydroxythioxanthone derivatives using binary acetonitrile-water mixtures as mobile phase has been examined. First, the variation in the retention time of each molecule as a function of mobile phase properties was studied by Kamlet-Taft solvatochromic equations. Then, the influences of molecular structure of the hydroxythioxanthone derivatives on their retention time in various mobile phase mixtures were investigated by quantitative structure-property relationship (QSPR) analysis. Finally, a unified model containing both the molecular structure parameters and mobile phase properties was developed to describe the chromatographic behavior of the systems studied. Among the solvent properties, polarity/polarizability parameter (π * ) and hydrogen-bond basicity (β), and among the solute properties, the most positive local charge (MPC), the sum of positive charges on hydrogen atoms contributing in hydrogen bonding (SPCH) and lipophilicity index (log P) were identified as controlling factors in the RP-HPLC behavior of hydroxythioxanthone derivatives in actonitrile-water binary solvents

Maternal High-Fat Diet Programming of the Neuroendocrine System and Behavior

Science.gov (United States)

Sullivan, Elinor L.; Riper, Kellie M.; Lockard, Rachel; Valleau, Jeanette C.

2015-01-01

Maternal obesity, metabolic state, and diet during gestation have profound effects on offspring development. The prevalence of neurodevelopmental and mental health disorders has risen rapidly in the last several decades in parallel with the rise in obesity rates. Evidence from epidemiological studies indicates that maternal obesity and metabolic complications increase the risk of offspring developing behavioral disorders such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASD), and schizophrenia. Animal models show that a maternal diet high in fat similarly disrupts behavioral programming of offspring, with animals showing social impairments, increased anxiety and depressive behaviors, reduced cognitive development, and hyperactivity. Maternal obesity, metabolic conditions, and high fat diet consumption increase maternal leptin, insulin, glucose, triglycerides, and inflammatory cytokines. This leads to increased risk of placental dysfunction, and altered fetal neuroendocrine development. Changes in brain development that likely contribute to the increased risk of behavioral and mental health disorders include increased inflammation in the brain, as well as alterations in the serotonergic system, dopaminergic system and hypothalamic pituitary adrenal (HPA) axis. PMID:25913366

Structure and phase formation behavior and dielectric and magnetic properties of lead iron tantalate-lead zirconate titanate multiferroic ceramics

Energy Technology Data Exchange (ETDEWEB)

Wongmaneerung, R., E-mail: re_nok@yahoo.com [Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Tipakontitikul, R. [Department of Physics, Ubonratchathani University, Ubonratchathani 31490 (Thailand); Jantaratana, P. [Department of Physics, Kasetsart University, Bangkok 10900 (Thailand); Bootchanont, A.; Jutimoosik, J.; Yimnirun, R. [School of Physics, Institute of Science, and NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Ananta, S. [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2016-03-15

Highlights: • The multiferroic ceramics consisted of PFT and PZT. • Crystal structure changed from cubic to mixedcubic and tetragonal with increasing PZT content. • Dielectric showed the samples underwent a typical relaxor ferroelectric behavior. • Magnetic properties showed very interesting behavior with square saturated magnetic hysteresis loops. - Abstract: Multiferroic (1 − x)Pb(Fe{sub 0.5}Ta{sub 0.5})O{sub 3}–xPb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3} (or PFT–PZT) ceramics were synthesized by solid-state reaction method. The crystal structure and phase formation of the ceramics were examined by X-ray diffraction (XRD). The local structure surrounding Fe and Ti absorbing atoms was investigated by synchrotron X-ray Absorption Near-Edge Structure (XANES) measurement. Dielectric properties were studied as a function of frequency and temperature using a LCR meter. A vibrating sample magnetometer (VSM) was used to determine the magnetic hysteresis loops. XRD study indicated that the crystal structure of the sample changed from pure cubic to mixed cubic and tetragonal with increasing PZT content. XANES measurements showed that the local structure surrounding Fe and Ti ions was similar. Dielectric study showed that the samples underwent a typical relaxor ferroelectric behavior while the magnetic properties showed very interesting behavior with square saturated magnetic hysteresis loops.

Near-surface modifications for improved crack tolerant behavior of high strength alloys: trends and prospects

International Nuclear Information System (INIS)

Hettche, L.R.; Rath, B.B.

1982-01-01

The purpose of this chapter is to examine the potential of surface modifications in improving the crack tolerant behavior of high strength alloys. Provides a critique of two of the most promising and versatile techniques: ion implantation and laser beam surface processing. Discusses crack tolerant properties; engineering characterization; publication trends and Department of Defense interests; and emergent surface modification techniques. Finds that the efficiency with which high strength alloys can be incorporated into a structure or component is dependent on the following crack tolerant properties: fracture toughness, fatigue resistance, sustained loading cracking resistance, fretting fatigue resistance, and hydrogen embrittlement resistance. Concludes that ion implantation and laser surface processing coupled with other advanced metallurgical procedures and fracture mechanic analyses provide the means to optimize both the bulk and surface controlled crack tolerant properties

Modeling fire behavior on tropical islands with high-resolution weather data

Science.gov (United States)

John W. Benoit; Francis M. Fujioka; David R. Weise

2009-01-01

In this study, we consider fire behavior simulation in tropical island scenarios such as Hawaii and Puerto Rico. The development of a system to provide real-time fire behavior prediction in Hawaii is discussed. This involves obtaining fuels and topography information at a fine scale, as well as supplying daily high-resolution weather forecast data for the area of...

Contributing Factors to Aggressive Behaviors in High School Students in Turkey

Science.gov (United States)

Kaya, Fadime; Bilgin, Hulya; Singer, Mark I.

2012-01-01

Violence among young people is an important public health topic as a universal problem. One of the recent issues concerning both the media and parents is the aggressive behavior among the high school students in Istanbul and the worldwide. The aim of this study was to investigate the types and rates of aggressive behavior and the contributing…

The Factor Structure of Preschool Learning Behaviors Scale Scores in Peruvian Children

Science.gov (United States)

Hahn, Kathryn R.; Schaefer, Barbara A.; Merino, Cesar; Worrell, Frank C.

2009-01-01

The factor structure of the Escala de Conductas de Aprendizaje Preescolar (ECAP), a Spanish translation of the Preschool Learning Behaviors Scale (PLBS), was examined in this study. Children aged 2 to 6 years (N = 328) enrolled in public and private preschools in the Republic of Peru were rated by classroom teachers on the frequency of observable,…

Conversational Behaviors in Youth with High-Functioning ASD and Asperger Syndrome

Science.gov (United States)

Paul, Rhea; Orlovski, Stephanie Miles; Marcinko, Hillary Chuba; Volkmar, Fred

2009-01-01

Twenty-nine youth with autism spectrum disorders and 26 with typical development between 12 and 18 years of age were engaged in structured interviews (ADOS). The interviews were videotaped and rated for atypical conversational behaviors by trained raters, using the Pragmatic Rating Scale (Landa et al. "Psychol Med" 22:245-254, 1992). The ASD group…

X-ray diffraction at high pressure and high/low temperatures using synchrotron radiation. Applications in the study of spinel structures

International Nuclear Information System (INIS)

Gerward, L.; Jiang, J.Z.; Olsen, J.S.; Recio, J.M.; Wakowska, A.

2004-01-01

High-pressure x-ray diffraction made a quantum leap in the 1960's with the advent of the diamond-anvil cell. This ingenious device, where two opposing diamond faces apply pressure to a tiny sample, made it possible to replicate the pressure near the core of the Earth by turning a thumbscrew. Multianvil cells, such as the Japanese MAX80 press, were developed for combined high-pressure and high-temperature studies. The availability n at about the same time n of dedicated synchrotron radiation sources of hard x-rays was another big step forward. Since then, the white-beam energy-dispersive method has been the workhorse for high pressure, high-temperature x-ray diffraction, although it is now gradually being replaced by high-resolution monochromatic methods based on the image plate, the CCD camera or other electronic area detectors. The first part of the paper is a review of high-pressure x-ray diffraction (HPXRD), covering roughly the last three decades. Physical parameters, such as the bulk modulus, the compressibility and the equation of state, are defined. The diamond-anvil cell, the multianvil press and other high-pressure devices are described, as well as synchrotron radiation sources and recording techniques. Examples are drawn from current experimental and theoretical research on crystal structures of the spinel type. Accurate structural parameters have been determined at ambient conditions and at low temperatures using single-crystal diffraction and four-circle diffractometers. The uniform high-pressure behavior of the oxide spinels has been investigated in detail and compared with the corresponding behavior of selenium-based spinels. The synthesis of advanced novel materials is exemplified in the case of the cubic spinel Si 3 N 4 . This and other nitrogen spinels, which have a bulk modulus of about 300 GPa modulated by the actual cation, are opening a road towards superhard materials. The paper finishes off with an outlook into the future, where new

Extraction of Structure Function and Gluon Distribution Function at Low-x from Cross Section Derivative by Regge Behavior

International Nuclear Information System (INIS)

Boroun, G.R.

2005-01-01

An approximation method based on Regge behavior is presented. This new method relates the reduced cross section derivative and the structure function Regge behavior at low x. With the use of this approximation method, the C and λ parameters are calculated from the HERA reduced cross section data taken at low-x. Also, we calculate the structure functions F 2 (x,Q 2 ) even for low-x values, which have not been investigated. To test the validity of calculated structure functions, we find the gluon distribution function in the Leading order approximation based on Regge behaviour of structure function and compare to the NLO QCD fit to H1 data and NLO parton distribution function.

The High Strain Rate Deformation Behavior of High Purity Magnesium and AZ31B Magnesium Alloy

Science.gov (United States)

Livescu, Veronica; Cady, Carl M.; Cerreta, Ellen K.; Henrie, Benjamin L.; Gray, George T.

The deformation in compression of pure magnesium and AZ31B magnesium alloy, both with a strong basal pole texture, has been investigated as a function of temperature, strain rate, and specimen orientation. The mechanical response of both metals is highly dependent upon the orientation of loading direction with respect to the basal pole. Specimens compressed along the basal pole direction have a high sensitivity to strain rate and temperature and display a concave down work hardening behavior. Specimens loaded perpendicularly to the basal pole have a yield stress that is relatively insensitive to strain rate and temperature and a work hardening behavior that is parabolic and then linearly upwards. Both specimen orientations display a mechanical response that is sensitive to temperature and strain rate. Post mortem characterization of the pure magnesium was conducted on a subset of specimens to determine the microstructural and textural evolution during deformation and these results are correlated with the observed work hardening behavior and strain rate sensitivities were calculated.

High temperature annealing effect on structural and magnetic properties of Ti/Ni multilayers

International Nuclear Information System (INIS)

Bhatt, Pramod; Ganeshan, V.; Reddy, V.R.; Chaudhari, S.M.

2006-01-01

High temperature annealing effect on structural and magnetic properties of Ti/Ni multilayer (ML) up to 600 deg. C have been studied and reported in this paper. Ti/Ni multilayer samples having constant layer thicknesses of 50 A each are deposited on float glass and Si(1 1 1) substrates using electron-beam evaporation technique under ultra-high vacuum (UHV) conditions at room temperatures. The micro-structural parameters and their evolution with temperature for as-deposited as well as annealed multilayer samples up to 600 deg. C in a step of 100 deg. C for 1 h are determined by using X-ray diffraction (XRD) and grazing incidence X-ray reflectivity techniques. The X-ray diffraction pattern recorded at 300 deg. C annealed multilayer sample shows interesting structural transformation (from crystalline to amorphous) because of the solid-state reaction (SSR) and subsequent re-crystallization at higher temperatures of annealing, particularly at ≥400 deg. C due to the formation of TiNi 3 and Ti 2 Ni alloy phases. Sample quality and surface morphology are examined by using atomic force microscopy (AFM) technique for both as-deposited as well as annealed multilayer samples. In addition to this, a temperature dependent dc resistivity measurement is also used to study the structural transformation and subsequent alloy phase formation due to annealing treatment. The corresponding magnetization behavior of multilayer samples after each stage of annealing has been investigated by using Magneto-Optical Kerr Effect (MOKE) technique and results are interpreted in terms of observed micro-structural changes

Inelastic seismic behavior of post-installed anchors for nuclear safety related structures: Generation of experimental database

Energy Technology Data Exchange (ETDEWEB)

Mahadik, Vinay, E-mail: vinay.mahadik@iwb.uni-stuttgart.de; Sharma, Akanshu; Hofmann, Jan

2016-02-15

Highlights: • Experiments for evaluating seismic behavior of anchors were performed. • Two undercut anchor products in use in nuclear facilities were considered. • Monotonic tension, shear and cycling tension tests at different crack widths. • Crack cycling tests at constant, in-phase and out-of phase tension loads. • Characteristics for the two anchors as a function of crack width were identified. - Abstract: Post installed (PI) anchors are often employed for connections between concrete structure and components or systems in nuclear power plants (NPP) and related facilities. Standardized practices for nuclear related structures demand stringent criteria, which an anchor has to satisfy in order to qualify for use in NPP related structures. In NPP and related facilities, the structure–component interaction in the event of an earthquake depends on the inelastic behavior of the concrete structure, the component system and also the anchorage system that connects them. For analysis, anchorages are usually assumed to be rigid. Under seismic actions, however, it is known that anchors may undergo significant plastic displacement and strength degradation. Analysis of structure–component interaction under seismic loads calls for numerical models simulating inelastic behavior of anchorage systems. A testing program covering different seismic loading scenarios in a reasonably conservative manner is required to establish a basis for generating numerical models of anchorage systems. Currently there is a general lack of modeling techniques to consider the inelastic behavior of anchorages in structure–component interaction under seismic loads. In this work, in view of establishing a basis for development of numerical models simulating the inelastic behavior of anchors, seismic tests on two different undercut anchors qualified for their use in NPP related structures were carried out. The test program was primarily based on the DIBt-KKW-Leitfaden (2010) guidelines

Impact of an Educational Text Message Intervention on Adolescents' Knowledge and High-Risk Behaviors.

Science.gov (United States)

Hickman, Nichole Erin; Schaar, Gina

2018-03-01

Health care providers need to develop improved methods of educating adolescents. This study was developed to evaluate adolescents' responses to and satisfaction with an educational text message intervention to promote healthy behaviors, reduce the incidence of unhealthy behaviors, and prevent high-risk behaviors. Adolescent participants received weekly text messages regarding high-risk sexual behaviors, healthy dietary habits, exercise, drug, or alcohol use, and social issues. Results indicate adolescents learned something new, made a behavioral change, and overall liked the delivery of educational information via text message. This indicates long-term continuation of a text message intervention is a viable means to deliver adolescent health information, thereby improving an adolescent's current and future health status.

Delinquent Behavior in High School Students in Hong Kong: Sociodemographic, Personal, and Family Determinants.

Science.gov (United States)

Shek, Daniel T L; Lin, Li

2016-02-01

On the basis of longitudinal data collected over 6 years, the changes in delinquent behavior and the related sociodemographic, personal, and family determinants were examined in this study. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: A 6-year longitudinal research design was used. Students responded to a questionnaire containing sociodemographic questions and validated measures of positive youth development, family functioning, and delinquent behavior. There was an increasing trend of delinquent behavior with the growth rate slowing down over the high school years. Male adolescents reported higher levels of delinquent behavior and showed a greater increase of delinquent behavior relative to female adolescents. Although positive youth development and family functioning were negatively associated with the initial level of delinquent behavior, they were positively associated with the growth rate of delinquent behavior over time. Delinquent behavior could be described by a quadratic growth curve during high school years. Gender, positive youth development, and family functioning influence the level and developmental trajectory of delinquent behavior in adolescence. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Uniaxial Extensional Behavior of A--B--A Thermoplastic Elastomers: Structure-Properties Relationship and Modeling

Science.gov (United States)

Martinetti, Luca

relation between the observed power-law exponent and molecular structure was established. The measured low-frequency response, originating from the incipient glass transition of the A domains, was exploited and extrapolated to lower frequencies via a sequential application of the fractional Maxwell model and the fractional Zener model. With only a few, physically meaningful material parameters a realistic description of the A--B--A self-similar relaxation was obtained over a frequency range much broader than the experimental window and not accessible via time-temperature superposition. The relationship between large-strain response and network structure of A--B--A triblocks was investigated, by examining (1) the effect of linear relaxation mechanisms on the tensile behavior, (2) the sources of elastic and viscoelastic nonlinearities, and (3) the strain rate dependence of the ultimate properties. For the first time in the literature, the complex high-dimensional rheological signature of chewing gum was analyzed, especially in response to nonlinear and unsteady deformations in both shear and extension. A unique rheological fingerprint was obtained that is sufficient to provide a new robust definition of chewing gum that is independent of specific molecular composition. (Abstract shortened by ProQuest.).

Seismic response analysis of nuclear reactor buildings under consideration of soil-structure interaction with torsional behavior

International Nuclear Information System (INIS)

Mizuno, N.; Iida, T.; Tsushima, Y.; Araki, T.; Nojima, O.

1977-01-01

In this paper, the seismic response analysis is described in detail for estimating the soil-structure interaction effects with the torsional behavior. The analytical method is firstly shown for estimating the stiffness of reactor building by the bending-shear and torsion theory of the thin wall sections in regard to the behavior of structure. The three-dimensional behavior of structure can be obtained more briefly and simply by the proposed method. Secondly, the dynamical soil-foundation coefficient for estimating the dissipation of vibrational energy on the ground is derived by H. Tajimi's theory which is based on a solution of the propagation of seismic waves caused by point excitation on the surface of the elastic half-space medium. The above results give the vibrational impedances of the soil-foundation corresponding to the static soil coefficient, which is defined to the excitation force in the frequency domain. In order to analyze to the equivalues of reactor building, the authors thirdly attempt to approximate the dynamic soil-foundation coefficient as the frequency transfer function of displacement. The complex damping is used for more suitably estimating the elastic structural damping effects of structure. The regression analysis of many degrees of freedom is fourthly attempted for estimating the natural periods annd equivalent viscous damping ratios directly from the experimental results by the forced vibrational test performed in 1974. The analytical results are finally shown for simulating and comparing with the above-mentioned experimental results

Testing the 8-syndrome structure of the child behavior checklist in 30 societies

DEFF Research Database (Denmark)

Ivanova, Masha Y; Dobrean, Anca; Dopfner, Manfred

2007-01-01

There is a growing need for multicultural collaboration in child mental health services, training, and research. To facilitate such collaboration, this study tested the 8-syndrome structure of the Child Behavior Checklist (CBCL) in 30 societies. Parents' CBCL ratings of 58,051 6- to 18-year-olds ...